WO2013027967A2 - Method for transmitting uplink control information, user equipment, method for receiving uplink control information, and base station - Google Patents

Abstract

The present invention comprises a PUCCH resource region per each format of downlink control information, which is transmittable through one downlink control channel. A user equipment decides which PUCCH resource in the PUCCH resource region would be used for transmitting PUCCH depending on which downlink control information format is detected. According the present invention, a risk of collision between PUCCH resources, when a cell transmitting a downlink signal and a cell receiving an uplink signal are different, can be prevented.

Description

Uplink control information transmission method and user equipment, uplink control information reception method and base station

The present invention relates to a wireless communication system. Specifically, the present invention relates to a method and apparatus for transmitting an uplink signal and a method and apparatus for receiving an uplink signal.

Various devices and technologies, such as smartphone-to-machine communication (M2M) and smart phones and tablet PCs, which require high data transmission rates, are emerging and spread. As a result, the amount of data required to be processed in a cellular network is growing very quickly. In order to meet this rapidly increasing data processing demand, carrier aggregation technology, cognitive radio technology, etc. to efficiently use more frequency bands, and increase the data capacity transmitted within a limited frequency Multi-antenna technology, multi-base station cooperation technology, and the like are developing. In addition, the communication environment is evolving in the direction of increasing the density of nodes that can be accessed by the user equipment in the vicinity. A node is a fixed point capable of transmitting / receiving a radio signal with a user device having one or more antennas. A communication system having a high density of nodes can provide higher performance communication services to user equipment by cooperation between nodes.

This multi-node cooperative communication method, in which a plurality of nodes communicate with a user equipment using the same time-frequency resources, is more efficient than a conventional communication method in which each node operates as an independent base station to communicate with a user equipment without mutual cooperation. It has much better performance in data throughput.

In a multi-node system, each node cooperates using a plurality of nodes, acting as base stations or access points, antennas, antenna groups, radio remote headers (RRHs), radio remote units (RRUs). Perform communication. Unlike conventional centralized antenna systems in which antennas are centrally located at a base station, in a multi-node system, the plurality of nodes are typically located more than a certain distance apart. The plurality of nodes may be managed by one or more base stations or base station controllers that control the operation of each node or schedule data to be transmitted / received through each node. Each node is connected to a base station or base station controller that manages the node through a cable or dedicated line.

Such a multi-node system can be viewed as a kind of multiple input multiple output (MIMO) system in that distributed nodes can simultaneously communicate with a single or multiple user devices by transmitting and receiving different streams. However, since the multi-node system transmits signals using nodes distributed in various locations, the transmission area that each antenna should cover is reduced as compared to the antennas provided in the existing centralized antenna system. Therefore, compared to the existing system implementing the MIMO technology in the centralized antenna system, in the multi-node system, the transmission power required for each antenna to transmit a signal can be reduced. In addition, since the transmission distance between the antenna and the user equipment is shortened, path loss is reduced, and high-speed data transmission is possible. Accordingly, the transmission capacity and power efficiency of the cellular system can be increased, and communication performance of relatively uniform quality can be satisfied regardless of the position of the user equipment in the cell. In addition, in a multi-node system, since the base station (s) or base station controller (s) connected to the plurality of nodes cooperate with data transmission / reception, signal loss occurring in the transmission process is reduced. In addition, when nodes located more than a certain distance to perform the cooperative communication with the user equipment, the correlation (correlation) and interference between the antennas are reduced. Therefore, according to the multi-node cooperative communication scheme, a high signal to interference-plus-noise ratio (SINR) can be obtained.

Due to the advantages of the multi-node system, the multi-node system is designed to reduce the cost of base station expansion and backhaul network maintenance in the next generation mobile communication system, and to increase service coverage and channel capacity and SINR. In parallel with or in place of a centralized antenna system, it is emerging as a new foundation for cellular communication.

With the introduction of a new wireless communication technology, not only the number of user equipments for which a base station should provide a service in a predetermined resource area increases, but also the uplink data and uplink data that the base station should receive from user equipments for providing a service. The amount of control information is increasing. Since the amount of radio resources available for the base station to communicate with the user device (s) is finite, the base station efficiently receives the user device (s) with uplink data and / or uplink control information using the finite radio resources. New measures are needed.

Accordingly, the present invention provides a method and apparatus for efficiently transmitting / receiving an uplink signal.

Technical problems to be achieved by the present invention are not limited to the above-mentioned technical problems, and other technical problems not mentioned above are apparent to those skilled in the art from the following detailed description. Can be understood.

In one aspect of the present invention, in the user equipment transmits an uplink signal to a base station in a wireless communication system, receiving downlink control information from the base station via a physical downlink shared channel (PDCCH); Transmit ACK / NACK (ACKnowledgment / Negative ACK) information associated with the downlink control information to the base station, and if the format of the downlink control information is a first format, a first PUCCH configured for the first format Uplink shared channel) in the second PUCCH resource region configured for the second format when the ACK / NACK information is transmitted using a first PUCCH resource in the resource region, and the format of the downlink control information is a second format. There is provided an uplink signal transmission method and a user equipment in which the ACK / NACK information is transmitted using a second PUCCH resource.

In another aspect of the present invention, in a wireless communication system, when a base station receives an uplink signal from a user equipment, the base station transmits downlink control information to the user equipment through a physical downlink shared channel (PDCCH); Receive ACK / NACK (ACKnowledgment / Negative ACK) information associated with the downlink control information from the user equipment. When the format of the downlink control information is a first format, a first PUCCH configured for the first format ( Physical Uplink Shared Channel) When the ACK / NACK information is received using a first PUCCH resource in a resource region, and the format of the downlink control information is a second format, a second PUCCH resource region configured for the second format An uplink signal receiving method and a base station for receiving the ACK / NACK information using a second PUCCH resource are provided.

In each aspect of the present invention, first indication information indicating the first PUCCH resource region and second indication information indicating the second PUCCH resource region may be further transmitted from the base station to the user equipment.

In each aspect of the present invention, the first indication information corresponds to an index of a starting first PUCCH resource in the first PUCCH resource region, and the second indication information is a starting second PUCCH resource in the second PUCCH resource region. It may correspond to an index of.

In each aspect of the present invention, each of the first PUCCH resource and the second PUCCH resource may be a resource linked to a control channel element (CCE) in the PDCCH.

In each aspect of the present invention, information indicating a transmission mode from the base station to the user device may be further transmitted, and the first format may be a format specific to the transmission mode.

The problem solving methods are only a part of embodiments of the present invention, and various embodiments reflecting the technical features of the present invention are based on the detailed description of the present invention described below by those skilled in the art. Can be derived and understood.

According to the present invention, when the cell for transmitting the downlink signal and the cell for receiving the uplink signal are different, the risk of PUCCH resources colliding can be prevented.

According to the present invention, the efficiency of uplink / downlink resource usage is increased.

The effects according to the present invention are not limited to the above-mentioned effects, and other effects not mentioned above may be clearly understood by those skilled in the art from the detailed description of the present invention. There will be.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are included as part of the detailed description in order to provide a thorough understanding of the present invention, provide an embodiment of the present invention and together with the description, illustrate the technical idea of the present invention.

1 shows an example of a radio frame structure used in a wireless communication system.

2 illustrates an example of a downlink (DL) / uplink (UL) slot structure in a wireless communication system.

FIG. 3 illustrates a downlink (DL) subframe structure used in a 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) / LTE-A (Advanced) system.

4 illustrates an example of an uplink (UL) subframe structure used in a 3GPP LTE / LTE-A system.

5 illustrates a logical arrangement of Physical Uplink Control CHannel (PUCCH) resources used in one cell.

6 shows an example of determining a dynamic PUCCH resource in a 3GPP LTE- (A) system.

7 illustrates an example of determining a dynamic PUCCH resource according to an embodiment of the present invention.

8 shows an example of CoMP (Coordinated Multi-Point transmission / reception) to which the present invention can be applied.

9 illustrates another example of determining a dynamic PUCCH resource according to an embodiment of the present invention.

10 shows another example of CoMP to which the present invention can be applied.

11 is a block diagram illustrating components of a transmitter 10 and a receiver 20 for carrying out the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. The detailed description, which will be given below with reference to the accompanying drawings, is intended to explain exemplary embodiments of the present invention and is not intended to represent the only embodiments in which the present invention may be practiced. The following detailed description includes specific details in order to provide a thorough understanding of the present invention. However, one of ordinary skill in the art appreciates that the present invention may be practiced without these specific details.

In some instances, well-known structures and devices may be omitted or shown in block diagram form centering on the core functions of the structures and devices in order to avoid obscuring the concepts of the present invention. In addition, the same components will be described with the same reference numerals throughout the present specification.

In the present invention, a user equipment (UE) may be fixed or mobile, and various devices which transmit and receive user data and / or various control information by communicating with a base station (BS) belong to this. The UE may be a terminal equipment (MS), a mobile station (MS), a mobile terminal (MT), a user terminal (UT), a subscriber station (SS), a wireless device, a personal digital assistant (PDA), or a wireless modem. It may be called a modem, a handheld device, or the like. In addition, in the present invention, a BS generally refers to a fixed station communicating with the UE and / or another BS, and communicates with the UE and another BS to exchange various data and control information. The BS may be referred to in other terms such as ABS (Advanced Base Station), NB (Node-B), eNB (evolved-NodeB), BTS (Base Transceiver System), Access Point (Access Point), and Processing Server (PS). In the following description of the present invention, BS is collectively referred to as eNB.

In the present invention, a node refers to a fixed point capable of transmitting / receiving a radio signal by communicating with a user equipment. Various forms of eNBs may be used as nodes regardless of their name. For example, the node may be a BS, an NB, an eNB, a pico-cell eNB (PeNB), a home eNB (HeNB), a relay, a repeater, and the like. Also, the node may not be an eNB. For example, it may be a radio remote head (RRH), a radio remote unit (RRU). RRHs, RRUs, etc. generally have a power level lower than the power level of the eNB. Since RRH or RRU, RRH / RRU) is generally connected to an eNB by a dedicated line such as an optical cable, RRH / RRU and eNB are generally compared to cooperative communication by eNBs connected by a wireless line. By cooperative communication can be performed smoothly. At least one antenna is installed at one node. The antenna may mean a physical antenna or may mean an antenna port, a virtual antenna, or an antenna group. Nodes are also called points. Unlike conventional centralized antenna systems (ie, single node systems) where antennas are centrally located at base stations and controlled by one eNB controller, in a multi-node system A plurality of nodes are typically located farther apart than a predetermined interval. The plurality of nodes may be managed by one or more eNBs or eNB controllers that control the operation of each node or schedule data to be transmitted / received through each node. Each node may be connected to the eNB or eNB controller that manages the node through a cable or dedicated line. In a multi-node system, the same cell identifier (ID) may be used or different cell IDs may be used for signal transmission / reception to / from a plurality of nodes. When a plurality of nodes have the same cell ID, each of the plurality of nodes behaves like some antenna group of one cell. If the nodes have different cell IDs in the multi-node system, such a multi-node system may be regarded as a multi-cell (eg, macro-cell / femto-cell / pico-cell) system. When the multiple cells formed by each of the plurality of nodes are configured to be overlaid according to coverage, the network formed by the multiple cells is particularly called a multi-tier network. The cell ID of the RRH / RRU and the cell ID of the eNB may be the same or may be different. When the RRH / RRU uses eNBs with different cell IDs, both the RRH / RRU and the eNB operate as independent base stations.

In the multi-node system of the present invention to be described below, one or more eNB or eNB controllers connected with a plurality of nodes may control the plurality of nodes to simultaneously transmit or receive signals to the UE via some or all of the plurality of nodes. Can be. Although there are differences between multi-node systems depending on the identity of each node, the implementation of each node, etc., these multi-nodes in that multiple nodes together participate in providing communication services to the UE on a given time-frequency resource. The systems are different from single node systems (eg CAS, conventional MIMO system, conventional relay system, conventional repeater system, etc.). Accordingly, embodiments of the present invention regarding a method for performing data cooperative transmission using some or all of a plurality of nodes may be applied to various kinds of multi-node systems. For example, although a node generally refers to an antenna group spaced apart from another node by a predetermined distance or more, embodiments of the present invention described later may be applied even when the node means any antenna group regardless of the interval. For example, in case of an eNB equipped with a cross polarized (X-pol) antenna, the eNB may control the node configured as the H-pol antenna and the node configured as the V-pol antenna, and thus embodiments of the present invention may be applied. .

Nodes that transmit / receive signals through a plurality of Tx / Rx nodes, transmit / receive signals through at least one node selected from a plurality of Tx / Rx nodes, or transmit downlink signals A communication scheme that enables different nodes to receive the uplink signal is called multi-eNB MIMO or CoMP (Coordinated Multi-Point TX / RX). Cooperative transmission schemes among such cooperative communication between nodes can be largely classified into joint processing (JP) and scheduling coordination. The former may be divided into joint transmission (JT) and dynamic point selection (DPS), and the latter may be divided into coordinated scheduling (CS) and coordinated beamforming (CB). DPS is also called dynamic cell selection (DCS). Compared to other cooperative communication techniques, more diverse communication environments may be formed when JP is performed among cooperative communication techniques among nodes. JT in JP refers to a communication scheme in which a plurality of nodes transmit the same stream to the UE. The UE recovers the stream by synthesizing the signals received from the plurality of nodes. In the case of JT, since the same stream is transmitted by a plurality of nodes, the reliability of signal transmission may be improved by transmission diversity. DPS in JP refers to a communication technique in which a signal is transmitted / received through one node selected according to a specific rule among a plurality of nodes. In the case of DPS, since a node having a good channel condition between the UE and the node will be selected as a communication node, the reliability of signal transmission can be improved.

Meanwhile, in the present invention, a cell refers to a certain geographic area in which one or more nodes provide a communication service. Therefore, in the present invention, communication with a specific cell may mean communication with an eNB or a node that provides a communication service to the specific cell. In addition, the downlink / uplink signal of a specific cell means a downlink / uplink signal from / to an eNB or a node that provides a communication service to the specific cell. In addition, the channel state / quality of a specific cell means a channel state / quality of a channel or communication link formed between an eNB or a node providing a communication service to the specific cell and a UE. In a 3GPP LTE-A based system, a UE transmits a downlink channel state from a specific node on a channel CSI-RS (Channel State Information Reference Signal) resource to which the antenna port (s) of the specific node is assigned to the specific node. Can be measured using CSI-RS (s). In general, adjacent nodes transmit corresponding CSI-RS resources on CSI-RS resources orthogonal to each other. Orthogonality of CSI-RS resources means that the CSI-RS is allocated by CSI-RS resource configuration, subframe offset, and transmission period that specify symbols and subcarriers carrying the CSI-RS. This means that at least one of a subframe configuration and a CSI-RS sequence for specifying the specified subframes are different from each other.

In the present invention, Physical Downlink Control CHannel (PDCCH) / Physical Control Format Indicator CHannel (PCFICH) / PHICH (Physical Hybrid automatic retransmit request Indicator CHannel) / PDSCH (Physical Downlink Shared CHannel) are respectively DCI (Downlink Control Information) / CFI ( Means a set of time-frequency resources or a set of resource elements that carry downlink format ACK / ACK / NACK (ACKnowlegement / Negative ACK) / downlink data, and also a physical uplink control channel (PUCCH) / physical (PUSCH). Uplink Shared CHannel / PACH (Physical Random Access CHannel) refers to a set of time-frequency resources or a set of resource elements that carry uplink control information (UCI) / uplink data / random access signals, respectively. A time-frequency resource assigned to or belonging to PDCCH / PCFICH / PHICH / PDSCH / PUCCH / PUSCH / PRACH; Resource elements (REs) are referred to as PDCCH / PCFICH / PHICH / PDSCH / PUCCH / PUSCH / PRACH RE or PDCCH / PCFICH / PHICH / PDSCH / PUCCH / PUSCH / PRACH resources, respectively. Hereinafter, the expression that the user equipment transmits PUCCH / PUSCH / PRACH is used as the same meaning as transmitting uplink control information / uplink data / random access signal on or through the PUSCH / PUCCH / PRACH, respectively. In addition, the expression that the eNB transmits PDCCH / PCFICH / PHICH / PDSCH is used in the same sense as transmitting downlink data / control information on or through the PDCCH / PCFICH / PHICH / PDSCH, respectively.

1 illustrates an example of a radio frame structure used in a wireless communication system. In particular, Figure 1 (a) shows a frame structure for frequency division duplex (FDD) used in the 3GPP LTE / LTE-A system, Figure 1 (b) is used in the 3GPP LTE / LTE-A system The frame structure for time division duplex (TDD) is shown.

Referring to FIG. 1, a radio frame used in a 3GPP LTE / LTE-A system has a length of 10 ms (307200 T _s ) and consists of 10 equally sized subframes (subframes). Numbers may be assigned to 10 subframes in one radio frame. Here, T _s represents the sampling time and is expressed as T _s = 1 / (2048 * 15 kHz). Each subframe has a length of 1 ms and consists of two slots. 20 slots in one radio frame may be sequentially numbered from 0 to 19. Each slot is 0.5ms long. The time for transmitting one subframe is defined as a transmission time interval (TTI). The time resource may be classified by a radio frame number (also called a radio frame index), a subframe number (also called a subframe number), a slot number (or slot index), and the like.

The radio frame may be configured differently according to the duplex mode. For example, in the FDD mode, since downlink transmission and uplink transmission are divided by frequency, a radio frame includes only one of a downlink subframe or an uplink subframe for a specific frequency band. In the TDD mode, since downlink transmission and uplink transmission are separated by time, a radio frame includes both a downlink subframe and an uplink subframe for a specific frequency band.

Table 1 illustrates a DL-UL configuration of subframes in a radio frame in the TDD mode.

Table 1

DL-UL configuration

Downlink-to-Uplink Switch-point periodicity

Subframe number

0

One

2

3

4

5

6

7

8

9

0

5 ms

D

S

U

U

U

D

S

U

U

U

One

5 ms

D

S

U

U

D

D

S

U

U

D

2

5 ms

D

S

U

D

D

D

S

U

D

D

3

10 ms

D

S

U

U

U

D

D

D

D

D

4

10 ms

D

S

U

U

D

D

D

D

D

D

5

10 ms

D

S

U

D

D

D

D

D

D

D

6

5 ms

D

S

U

U

U

D

S

U

U

D

In Table 1, D represents a downlink subframe, U represents an uplink subframe, and S represents a special subframe. The singular subframe includes three fields of Downlink Pilot TimeSlot (DwPTS), Guard Period (GP), and Uplink Pilot TimeSlot (UpPTS). DwPTS is a time interval reserved for downlink transmission, and UpPTS is a time interval reserved for uplink transmission. Table 2 illustrates the configuration of a singular frame.

TABLE 2

Special subframe configuration	Normal cyclic prefix in downlink			Extended cyclic prefix in downlink
	DwPTS	UpPTS		DwPTS	UpPTS
		Normal cyclic prefix in uplink	Extended cyclic prefix in uplink		Normal cyclic prefix in uplink	Extended cyclic prefix in uplink
0	6592T s	2192T s	2560T s	7680T s	2192T s	2560T s
One	19760T s			20480T s
2	21952T s			23040T s
3	24144T s			25600T s
4	26336T s			7680T s	4384T s	5120T s
5	6592T s	4384T s	5120T s	20480T s
6	19760T s			23040T s
7	21952T s			-	-	-
8	24144T s			-	-	-

2 illustrates an example of a downlink / uplink (DL / UL) slot structure in a wireless communication system. In particular, FIG. 2 shows a structure of a resource grid of a 3GPP LTE / LTE-A system. There is one resource grid per antenna port.

Referring to FIG. 2, a slot includes a plurality of Orthogonal Frequency Division Multiplexing (OFDM) symbols in a time domain and a plurality of resource blocks (RBs) in a frequency domain. An OFDM symbol may mean a symbol period. Referring to FIG. 2, a signal transmitted in each slot may be represented by a resource grid including N ^{DL / UL} _RB * N ^RB _sc subcarriers and N ^{DL / UL} _symb OFDM symbols. . Here, N ^DL _RB represents the number of resource blocks (RBs) in the downlink slot, and N ^UL _RB represents the number of _RBs in the UL slot. N ^DL _RB and N ^UL _RB depend on DL transmission bandwidth and UL transmission bandwidth, respectively. N ^DL _symb represents the number of OFDM symbols in the downlink slot, and N ^UL _symb represents the number of OFDM symbols in the UL slot. N ^RB _sc represents the number of subcarriers constituting one RB.

The OFDM symbol may be called an OFDM symbol, a Single Carrier Frequency Division Multiplexing (SC-FDM) symbol, or the like according to a multiple access scheme. The number of OFDM symbols included in one slot may vary depending on the channel bandwidth and the length of the cyclic prefix (CP). For example, in case of a normal CP, one slot includes 7 OFDM symbols, whereas in case of an extended CP, one slot includes 6 OFDM symbols. Although FIG. 2 illustrates a subframe in which one slot includes 7 OFDM symbols for convenience of description, embodiments of the present invention can be applied to subframes having other numbers of OFDM symbols in the same manner. Referring to FIG. 2, each OFDM symbol includes N ^{DL / UL} _RB * N ^RB _sc subcarriers in the frequency domain. The types of subcarriers may be divided into data subcarriers for data transmission, reference signal subcarriers for transmission of reference signals, null subcarriers for guard band, and direct current (DC) components. . The null subcarrier for the DC component is a subcarrier left unused and is mapped to a carrier frequency f ₀ during an OFDM signal generation process or a frequency upconversion process. The carrier frequency is also called the center frequency.

One RB is defined as N ^{DL / UL} _symb (e.g., seven) consecutive OFDM symbols in the time domain and is defined by N ^RB _sc (e.g., twelve) consecutive subcarriers in the frequency domain. Is defined. For reference, a resource composed of one OFDM symbol and one subcarrier is called a resource element (RE) or tone. Therefore, one RB is composed of N ^{DL / UL} _symb * N ^RB _sc resource elements. Each resource element in the resource grid may be uniquely defined by an index pair (k, 1) in one slot. k is an index given from 0 to N ^{DL / UL} _RB * N ^RB _sc −1 in the frequency domain, and l is an index given from 0 to N ^{DL / UL} _symb −1 in the time domain.

Two ^RBs , each occupying N ^RB _sc consecutive subcarriers in one subframe and one located in each of two slots of the subframe, are called a physical resource block (PRB) pair. Two RBs constituting a PRB pair have the same PRB number (or also referred to as a PRB index).

3 illustrates a downlink (DL) subframe structure used in a 3GPP LTE / LTE-A system.

Referring to FIG. 3, a DL subframe is divided into a control region and a data region in the time domain. Referring to FIG. 3, up to three (or four) OFDM symbols located in the first slot of a subframe correspond to a control region to which a control channel is allocated. Hereinafter, a resource region available for PDCCH transmission in a DL subframe is called a PDCCH region. The remaining OFDM symbols other than the OFDM symbol (s) used as the control region correspond to a data region to which a Physical Downlink Shared CHannel (PDSCH) is allocated. Hereinafter, a resource region available for PDSCH transmission in a DL subframe is called a PDSCH region. Examples of DL control channels used in 3GPP LTE include a physical control format indicator channel (PCFICH), a physical downlink control channel (PDCCH), a physical hybrid ARQ indicator channel (PHICH), and the like. The PCFICH is transmitted in the first OFDM symbol of a subframe and carries information about the number of OFDM symbols used for transmission of a control channel within the subframe. The PHICH carries a Hybrid Automatic Repeat Request (HARQ) ACK / NACK (acknowledgment / negative-acknowledgment) signal in response to the UL transmission.

Control information transmitted through the PDCCH is referred to as downlink control information (DCI). DCI includes resource allocation information and other control information for the UE or UE group. For example, the DCI includes a transmission format and resource allocation information of a downlink shared channel (DL-SCH), a transmission format and resource allocation information of an uplink shared channel (UL-SCH), and a paging channel. channel, PCH) paging information, system information on the DL-SCH, resource allocation information of an upper layer control message such as a random access response transmitted on the PDSCH, transmission power control command for individual UEs in the UE group ( It includes a Transmit Control Command Set, a Transmit Power Control command, activation indication information of Voice over IP (VoIP), a Downlink Assignment Index (DAI), and the like. The transmission format and resource allocation information of a downlink shared channel (DL-SCH) may also be called DL scheduling information or a DL grant, and may be referred to as an uplink shared channel (UL-SCH). The transmission format and resource allocation information is also called UL scheduling information or UL grant. The DCI carried by one PDCCH has a different size and use depending on the DCI format, and its size may vary depending on a coding rate. In the current 3GPP LTE system, various formats such as formats 0 and 4 for uplink and formats 1, 1A, 1B, 1C, 1D, 2, 2A, 2B, 2C, 3, and 3A are defined for uplink. Hopping flag, RB allocation, modulation coding scheme (MCS), redundancy version (RV), new data indicator (NDI), transmit power control (TPC), and cyclic shift DMRS Control information such as shift demodulation reference signal (UL) index, channel quality informaiton (CQI) request, DL assignment index (DL assignment index), HARQ process number, transmitted precoding matrix indicator (TPMI), and precoding matrix indicator (PMI) information The selected combination is transmitted to the UE as downlink control information. Table 3 shows an example of the DCI format.

TABLE 3

DCI format	Description
0	Resource grants for the PUSCH transmissions (uplink)
One	Resource assignments for single codeword PDSCH transmissions
1A	Compact signaling of resource assignments for single codeword PDSCH
1B	Compact resource assignments for PDSCH using rank-1 closed loop precoding
1C	Very compact resource assignments for PDSCH (eg paging / broadcast system information)
1D	Compact resource assignments for PDSCH using multi-user MIMO
2	Resource assignments for PDSCH for closed-loop MIMO operation
2A	Resource assignments for PDSCH for open-loop MIMO operation
2B	Resource assignments for PDSCH using up to 2 antenna ports with UE-specific reference signals
2C	Resource assignment for PDSCH using up to 8 antenna ports with UE-specific reference signals
3 / 3A	Power control commands for PUCCH and PUSCH with 2-bit / 1-bit power adjustments
4	Scheduling of PUSCH in one UL Component Carrier with multi-antenna port transmission mode

In general, the DCI format that can be transmitted to the UE depends on the transmission mode (TM) configured in the UE. In other words, not all DCI formats may be used for a UE configured in a specific transmission mode, but only certain DCI format (s) corresponding to the specific transmission mode may be used.

The PDCCH is transmitted on an aggregation of one or a plurality of consecutive control channel elements (CCEs). CCE is a logical allocation unit used to provide a PDCCH with a coding rate based on radio channel conditions. The CCE corresponds to a plurality of resource element groups (REGs). For example, one CCE corresponds to nine REGs and one REG corresponds to four REs. In the 3GPP LTE system, a CCE set in which a PDCCH can be located is defined for each UE. The set of CCEs in which a UE can discover its PDCCH is referred to as a PDCCH search space, simply a search space (SS). An individual resource to which a PDCCH can be transmitted in a search space is called a PDCCH candidate. The collection of PDCCH candidates that the UE will monitor is defined as a search space. In the 3GPP LTE / LTE-A system, a search space for each DCI format may have a different size, and a dedicated search space and a common search space are defined. The dedicated search space is a UE-specific search space and is configured for each individual UE. The common search space is configured for a plurality of UEs. Table 4 illustrates the aggregation levels that define the search spaces.

Table 4

Search space			Number of PDCCH candidates M (L)
Type	Aggregation level L	Size [in CCEs]
UE-specific	One	6	6
	2	12	6
	4	8	2
	8	16	2
Common	4	16	4
	8	16	2

One PDCCH candidate corresponds to 1, 2, 4, or 8 CCEs according to a CCE aggregation level. The eNB sends the actual PDCCH (DCI) on any PDCCH candidate in the search space, and the UE monitors the search space to find the PDCCH (DCI). Here, monitoring means attempting decoding of each PDCCH in a corresponding search space according to all monitored DCI formats. The UE may detect its own PDCCH by monitoring the plurality of PDCCHs. Basically, since the UE does not know where its PDCCH is transmitted, every Pframe attempts to decode the PDCCH until every PDCCH of the corresponding DCI format has detected a PDCCH having its own identifier. It is called blind detection (blind decoding).

On the other hand, in order to reduce the overhead of blind decoding, the number of DCI formats is defined smaller than the type of control information transmitted using the PDCCH. The DCI format includes a plurality of different information fields. The type of the information field, the number of information fields, the number of bits of each information field, etc. vary according to the DCI format. In addition, the size of control information matched to the DCI format varies according to the DCI format. Any DCI format may be used for transmitting two or more kinds of control information.

Table 5 shows an example of control information transmitted by DCI format 0. In the following, the bit size of each information field is merely an example, and does not limit the bit size of the field.

Table 5

	Information field	bit (s)
(One)	Flag for format 0 / format 1A differentiation	One
(2)	Hopping flag	One
(3)	Resource block assignment and hopping resource allocation	ceil {log 2 (N UL RB (N UL RB +1) / 2)}
(4)	Modulation and coding scheme and redundancy version	5
(5)	New data indicator	One
(6)	TPC command for scheduled PUSCH	2
(7)	Cyclic shift for DMRS	3
(8)	UL index (TDD)	2
(9)	CQI request	One

The flag field is an information field for distinguishing between format 0 and format 1A. That is, DCI format 0 and DCI format 1A have the same payload size and are distinguished by the flag field. The resource block allocation and hopping resource allocation fields may have different bit sizes according to a hopping PUSCH or a non-hoppping PUSCH. The _RB Allocation and Hopping Resource Allocation field for the non-hopping PUSCH provides the ceil {log ₂ (N ^UL _RB (N ^UL _RB +1) / 2)} bit to the resource allocation of the first slot in the uplink subframe. . Here, N ^UL _RB is the number of resource blocks included in the uplink slot and depends on the uplink transmission bandwidth configured in the cell. Therefore, the payload size of DCI format 0 may vary depending on the uplink bandwidth. DCI format 1A includes an information field for PDSCH allocation, and the payload size of DCI format 1A may also vary according to downlink bandwidth. DCI format 1A provides reference information bit size for DCI format 0. Thus, if the number of information bits of DCI format 0 is less than the number of information bits of DCI format 1A, '0' is added to DCI format 0 until the payload size of DCI format 0 is equal to the payload size of DCI format 1A. Is added. The added '0' is filled in the padding field of the DCI format.

On the other hand, not all DCI formats are searched simultaneously in order to keep the computational load resulting from the blind decoding attempt below a certain level. For example, the UE is semi-statically configured by higher layer signaling to receive PDSCH data transmissions signaled on the PDCCH in accordance with one of transmission modes 1-9. Table 6 illustrates a transmission mode for configuring a multi-antenna technique and a DCI format in which the UE performs blind decoding in the transmission mode.

Table 6

Transmission mode	DCI format	Search space	Transmission scheme of PDSCH corresponding to PDCCH
Mode 1	DCI format 1A	Common andUE specific by C-RNTI	Single-antenna port, port 0
	DCI format 1	UE specific by C-RNTI	Single-antenna port, port 0
Mode 2	DCI format 1A	Common andUE specific by C-RNTI	Transmit diversity
	DCI format 1	UE specific by C-RNTI	Transmit diversity
Mode 3	DCI format 1A	Common andUE specific by C-RNTI	Transmit diversity
	DCI format 2A	UE specific by C-RNTI	Large delay CDD or Transmit diversity
Mode 4	DCI format 1A	Common andUE specific by C-RNTI	Transmit diversity
	DCI format 2	UE specific by C-RNTI	Closed-loop spatial multiplexing or Transmit diversity
Mode 5	DCI format 1A	Common andUE specific by C-RNTI	Transmit diversity
	DCI format 1D	UE specific by C-RNTI	Multi-user MIMO
Mode 6	DCI format 1A	Common andUE specific by C-RNTI	Transmit diversity
	DCI format 1B	UE specific by C-RNTI	Closed-loop spatial multiplexing using a single transmission layer
Mode 7	DCI format 1A	Common andUE specific by C-RNTI	If the number of PBCH antenna ports is one, Single antenna port, port 0 is used, otherwise Transmit diversity
	DCI format 1	UE specific by C-RNTI	Single-antenna port, port 5
Mode 8	DCI format 1A	Common andUE specific by C-RNTI	If the number of PBCH antenna ports is one, Single antenna port, port 0 is used, otherwise Transmit diversity
	DCI format 2B	UE specific by C-RNTI	Dual laayer transmission, port 7 and 8 or single-antenna port, port 7 or 8
Mode 9	DCI format 1A	Common andUE specific by C-RNTI	Non-MBSFN subframe: If the number of PBCH antenna ports is one, Single-antenna port, port 0 is used, otherwise If the number of PBCH antenna ports is one, Single antenna port, port 0 is used, otherwise Transmit diversity Single-antenna port, port 7
	DCI format 2C	UE specific by C-RNTI	Up to 8 layer transmission, ports 7-14

In particular, Table 6 shows the relationship between PDCCH and PDSCH configured by Cell Radio Network Temporary Identifier (C-RNTI), and the UE configured to decode PDCCH with CRC scrambled to C-RNTI by higher layer is the PDCCH. Decode and decode the corresponding PDSCH according to each combination defined in Table 6. For example, if the UE is configured in transmission mode 1 by higher layer signaling, the PDCCH is decoded by the DCI formats 1A and 1, respectively, to obtain one of the DCI of the DCI format 1A and the DCI of the DCI format 1.

When the transmission / reception of the PDCCH is described in more detail, the eNB generates control information according to the DCI format. The eNB may select one DCI format from among a plurality of DCI formats (DCI formats 1, 2, ..., N) according to control information to be sent to the UE. A cyclic redundancy check (CRC) for error detection is attached to control information generated according to each DCI format. In the CRC, an identifier (eg, Radio Network Temporary Identifier) (RNTI) is masked according to the owner or purpose of the PDCCH. In other words, the PDCCH is CRC scrambled with an identifier (eg, RNTI). If C-RNTI is used, the PDCCH carries control information for that particular UE, and other RNTIs (e.g., Paging RNTI (P-RNTI), System Information RNTI (SI-RNTI), RA-RNTI (Random) Access RNTI)) is used, the PDCCH carries common control information received by all UEs in the cell. The eNB performs channel coding on the control information added with the CRC to generate coded data. Rate matching is performed according to a CCE aggregation level allocated to the DCI format, and modulated coded data are generated to generate modulation symbols. The modulation symbols constituting one PDCCH may have one of 1, 2, 4, and 8 CCE aggregation levels. Modulation symbols are mapped to CCE to RE mapping. The UE demaps the physical resource element to the CCE to detect the PDCCH. Since the UE does not know at which CCE aggregation level it should receive the PDCCH, it demodulates each CCE aggregation level. The UE performs rate dematching on the demodulated data. Since the UE does not know which DCI format (or DCI payload size) it should receive control information, the UE performs rate de-matching for each DCI format (or DCI payload size) for the configured transmission mode. Perform. Channel decoding is performed on the rate dematched data according to the code rate, and the CRC is checked to detect whether an error occurs. If no error occurs, the UE may determine that it has detected its PDCCH. If an error occurs, the UE continues to perform blind decoding for different CCE aggregation levels or for different DCI formats (or DCI payload sizes). Upon detecting its own PDCCH, the UE removes the CRC from the decoded data and obtains control information.

The eNB may transmit data for the UE or the UE group through the data area. Data transmitted through the data area is also called user data. For transmission of user data, a physical downlink shared channel (PDSCH) may be allocated to the data area. Paging channel (PCH) and downlink-shared channel (DL-SCH) are transmitted through PDSCH. The UE may read data transmitted through the PDSCH by decoding control information transmitted through the PDCCH. Information indicating to which UE or UE group data of the PDSCH is transmitted, how the UE or UE group should receive and decode PDSCH data, and the like are included in the PDCCH and transmitted. For example, a specific PDCCH is masked with a cyclic redundancy check (CRC) with a Radio Network Temporary Identity (RNTI) of "A", a radio resource (eg, a frequency location) of "B" and a transmission of "C". It is assumed that information about data transmitted using format information (eg, transport block size, modulation scheme, coding information, etc.) is transmitted through a specific DL subframe. The UE monitors the PDCCH using its own RNTI information, and the UE having the RNTI "A" detects the PDCCH, and the PDSCH indicated by "B" and "C" through the received PDCCH information. Receive

4 illustrates an example of an uplink (UL) subframe structure used in a 3GPP LTE / LTE-A system.

Referring to FIG. 4, the UL subframe may be divided into a control region and a data region in the frequency domain. One or several physical uplink control channels (PUCCHs) may be allocated to the control region to carry uplink control information (UCI). One or several physical uplink shared channels (PUSCHs) may be allocated to a data region of a UL subframe to carry user data. The PUSCH may be transmitted together with a DeModulation Reference Signal (DMRS), which is a reference signal (RS) for demodulation of user data transmitted through the PUSCH. The control region and data region in the UL subframe may also be called a PUCCH region and a PUSCH region, respectively. A sounding reference signal (SRS) may be allocated to the data area. The SRS is transmitted in the OFDM symbol located at the end of the UL subframe in the time domain and in the data transmission band of the UL subframe, that is, in the data domain, in the frequency domain. SRSs of several UEs transmitted / received in the last OFDM symbol of the same subframe may be distinguished according to frequency location / sequence.

DMRS or SRS, associated with PUSCH transmission or PUCCH transmission, is defined by the cyclic shift of the base sequence according to a predetermined rule. For example, the reference signal RS sequence r ^(α) _{u, v} (n) may be defined as e ^jαn r _{u, v} (n) (0 ≦ n ≦ M ^RS _sc ). Here, M ^RS _sc = mN ^RB _sc is the length of the RS sequence, 1≤m≤N ^{max, UL} _RB . N ^{max, UL} _RB expressed as an integer multiple of N ^RB _sc means the largest uplink bandwidth configuration. A plurality of RS sequences may be defined from one base sequence through different cyclic shift values α. A plurality of basic sequences are defined for DMRS and SRS. For example, basic sequences can be defined using the root Zadoff-Chu sequence. The basic sequences r _{u, v} (n) are divided into groups. Each group base sequence group contains one or more base sequences. For example, each of the base sequence groups, each length _{^{M RS sc = mN RB sc (}} 1≤m≤5) of one base sequence (v = 0) and the respective length of M _sc ^RS = mN _sc ^RB (6≤ m ≦ N ^RB _sc ) may include two basic sequences. r _{u, v} (n) to u∈ {0,1,... , 29} is the group number (that is, the group index), v represents the base sequence number (that is, the base sequence index) within that group, and each base sequence group number and the base sequence number within that group may change over time. Can be. The sequence group number u in slot n _s is defined by the group hopping pattern and the sequence transition pattern. There are a plurality of different hopping patterns and a plurality of different sequence transition patterns. PUCCH and PUSCH have the same hopping pattern, but may have different sequence transition patterns. The group hopping pattern may be given cell-specific using a pseudo-random sequence generator using N ^cell _ID . The pseudo-random sequence for the group hopping pattern is initialized to a specific initial value (eg c _init = floor (N ^cell _ID / 30)) at the beginning of each radio frame. The sequence transition pattern f ^PUCCH _ss for ^PUCCH may be given based on a cell ID (eg f ^PUCCH _ss = N ^cell _ID mod 30), and the sequence transition pattern f ^PUSCH _ss for ^PUSCH is a value configured by a higher layer ( Δ _ss ) (eg, f ^PUSCH _ss = (f ^PUCCH _ss + Δ _ss ) mod 30), where Δ _ss ∈ {0, 1, ..., 29}).

For example, the PUSCH DMRS sequence r ^(λ) _PUSCH (m · M ^RS _sc + n) associated with the layer λ∈ {0,1, ..., υ-1} is w ^(λ) (m) r ^{( α_λ)} _{u, v} (n). Here, m = 0, 1, n = 0, ..., M ^RS _sc -1, M ^RS _sc = M ^PUSCH _sc . M ^PUSCH _sc is a bandwidth scheduled for uplink transmission and means the number of subcarriers. Orthogonal sequence w ^(λ) (m) may be given by Table 7 below using the cyclic shift field in the most recent uplink-related DCI for the transport block associated with the corresponding PUSCH transmission. The cyclic shift α_λ in the slot n _s can be given as 2πn _{cs, λ} / 12. Where n _{cs, λ} = (n ⁽¹⁾ _DMRS + n ⁽²⁾ _{DMRS, λ} + n _PN (n _s )) mod 12, and n _PN (n _s ) is a pseudo-random sequence c (i) Can be given. c (i) may be cell specific, and the pseudo-random sequence generator is initialized to a specific initial value (which may be cell-specific) at the beginning of each radio frame. For example, c (i) may be initialized with c _init = floor (N ^cell _ID / 30) · 2 ⁵ + f ^PUSCH _ss . n ⁽¹⁾ _DMRS may be given by Table 8 according to the cyclicShift parameter given by higher layer signaling, and n ⁽²⁾ _{DMRS, λ} is the most recent uplink for the transport block associated with the corresponding PUSCH transmission. The cyclic shift for the DMRS field in the link-related DCI can be given according to Table 7 below.

Table 7 illustrates the mapping of the cyclic shift field in the uplink-related DCI format to n ⁽²⁾ _{DMRS, λ} and [w ^(λ) (0) w ^(λ) (1)].

TABLE 7

Table 8 is an illustration of a n ⁽¹⁾ mapping the _DMRS deulroui cycle transition (cyclicShift) by a higher layer signaling.

Table 8

When the UE adopts a Single Carrier Frequency Division Multiplexing Access (SC-FDMA) scheme for UL transmission, in order to maintain a single carrier characteristic, in a 3GPP LTE release 8 or release 9 system, PUCCH and PUSCH are performed on one carrier. Can't send at the same time. In the 3GPP LTE Release 10 system, whether to support simultaneous transmission of a PUCCH and a PUSCH may be indicated in a higher layer.

In the UL subframe, subcarriers having a long distance based on a direct current (DC) subcarrier are used as a control region. In other words, subcarriers located at both ends of the UL transmission bandwidth are allocated for transmission of uplink control information. The DC subcarrier is a component that is not used for signal transmission and is mapped to a carrier frequency f ₀ during frequency upconversion. The PUCCH for one UE is allocated to an RB pair belonging to resources operating at one carrier frequency in one subframe, and the RBs belonging to the RB pair occupy different subcarriers in two slots. The PUCCH allocated in this way is expressed as that the RB pair allocated to the PUCCH is frequency hopped at the slot boundary. However, if frequency hopping is not applied, RB pairs occupy the same subcarrier.

PUCCH may be used to transmit the following control information.

SR (Scheduling Request): Information used for requesting an uplink UL-SCH resource. It is transmitted using OOK (On-Off Keying) method.

HARQ-ACK: A response to a PDCCH and / or a response to a downlink data packet (eg, codeword) on a PDSCH. This indicates whether the PDCCH or PDSCH is successfully received. One bit of HARQ-ACK is transmitted in response to a single downlink codeword, and two bits of HARQ-ACK are transmitted in response to two downlink codewords. HARQ-ACK response includes a positive ACK (simple, ACK), negative ACK (hereinafter, NACK), DTX (Discontinuous Transmission) or NACK / DTX. Here, HARQ-ACK is mixed with HARQ ACK / NACK, ACK / NACK.

Channel State Information (CSI): Feedback information for the downlink channel. Multiple Input Multiple Output (MIMO) -related feedback information includes a rank indicator (RI) and a precoding matrix indicator (PMI).

The amount of uplink control information (UCI) that a UE can transmit in a subframe depends on the number of SC-FDMA available for control information transmission. SC-FDMA available for UCI means the remaining SC-FDMA symbol except for the SC-FDMA symbol for transmitting the reference signal in the subframe, and in the case of a subframe including a Sounding Reference Signal (SRS), the last SC of the subframe The -FDMA symbol is also excluded. The reference signal is used for coherent detection of the PUCCH. PUCCH supports various formats according to the transmitted information.

Table 9 shows a mapping relationship between PUCCH format and UCI in LTE / LTE-A system.

Table 9

PUCCH format	Modulation scheme	Number of bits per subframe	Usage	Etc.
One	N / A	N / A (exist or absent)	SR (Scheduling Request)
1a	BPSK	One	ACK / NACK orSR + ACK / NACK	One codeword
1b	QPSK
	2	ACK / NACK orSR + ACK / NACK	Two codeword
2	QPSK	20	CQI / PMI / RI	Joint coding ACK / NACK (extended CP)
2a	QPSK + BPSK	21	CQI / PMI / RI + ACK / NACK	Normal CP only
2b	QPSK + QPSK	22	CQI / PMI / RI + ACK / NACK	Normal CP only
3	QPSK	48	ACK / NACK orSR + ACK / NACK orCQI / PMI / RI + ACK / NACK

Referring to Table 9, the PUCCH format 1 series is mainly used to transmit ACK / NACK information, and the PUCCH format 2 series is mainly used to carry channel state information (CSI) such as CQI / PMI / RI. In particular, the PUCCH format 3 series is mainly used to transmit ACK / NACK information.

The UE is allocated a PUCCH resource for transmission of the UCI from the eNB in an explicit manner by an upper layer signal or an implicit manner by a dynamic control signal. The physical resources used for the PUCCH depend on two parameters given by higher layers, N ⁽²⁾ _RB and N ⁽¹⁾ _cs . The variable N ⁽²⁾ _RB ≧ 0 represents the bandwidth available for PUCCH format 2 / 2a / 2b transmission in each slot and is expressed as N ^RB _sc integer multiples. Variable N ⁽¹⁾ _cs is the number of cyclic shifts (CS) used for PUCCH format 1 / 1a / 1b in the resource block used for mixing of formats 1 / 1a / 1b and 2 / 2a / 2b. Indicates. The value of N ⁽¹⁾ _cs becomes an integer multiple of Δ ^PUCCH _shift within the range of {0, 1, ..., 7}. Δ ^PUCCH _shift is provided by a higher layer. When N ⁽¹⁾ _cs = 0, there are no mixed resource blocks, and at most one resource block supports mixing of formats 1 / 1a / 1b and 2 / 2a / 2b in each slot. The resources used for transmission of PUCCH formats 1 / 1a / 1b, 2 / 2a / 2b, and 3 by antenna port p are non-negative integer indexes n ^{(1, p)} _PUCCH , n ^{(2, p)} _PUCCH < N ⁽²⁾ _RB N ^RB _sc + ceil (N ⁽¹⁾ _cs / 8). (N ^RB _sc -N ⁽¹⁾ _cs -2) and n ^{(2, p)} _PUCCH , respectively.

Specifically, according to a specific rule defined for each PUCCH format, an orthogonal sequence and / or cyclic shift to be applied to a corresponding UCI is determined from a PUCCH resource index, and resource indexes of two resource blocks in a subframe to which a PUCCH is mapped are given. For example, a PRB for transmission of a PUCCH in slot n _s is given as follows.

Equation 1

In Equation 1, the variable m depends on the PUCCH format, and is given to the PUCCH format 1 / 1a / 1b, the PUCCH format 2 / 2a / 2b, and the PUCCH format 3 by Equation 2, Equation 3, and Equation 4, respectively.

Equation 2

In Equation 2, n ^{(1, p)} _PUCCH is a PUCCH resource index of antenna port p for PUCCH format 1 / 1a / 1b, and in the case of ACK / NACK PUCCH, the first CCE index of PDCCH carrying scheduling information of the corresponding PDSCH This is an implicit value.

Equation 3

n ^{(2, p)} _PUCCH is a PUCCH resource index of antenna port p for PUCCH format 2 / 2a / 2b, and is a value transmitted from eNB to UE by higher layer signaling.

Equation 4

n ^{(3, p)} _PUCCH is a PUCCH resource index of antenna port p for PUCCH format 3, and is a value transmitted from eNB to UE by higher layer signaling. N ^PUCCH _{SF, 0} represents a spreading factor for the first slot of a subframe. N ^PUCCH for all within two slot sub-frame using a common PUCCH Format 3 _{SF, 0} to 5, and, N ^PUCCH for the first slot and the second slot from using a reduced PUCCH Format 3 sub-frames _{SF, 0} Are 5 and 4, respectively.

5 illustrates a logical arrangement of Physical Uplink Control CHannel (PUCCH) resources used in one cell.

PUCCH resources are configured based on cell ID. The UE acquires a cell ID of a cell to which the UE is connected and configures PUCCH resources for PUCCH transmission in the cell, that is, PUCCH transmission to a node of the cell based on the cell ID. PUCCH resources configured based on one cell ID include PUCCH resources for transmission of CSI, PUCCH resources for transmission of semi-persistent scheduling (SPS) ACK / NACK and SR, and PUCCH resources for transmission of dynamic ACK / NACK. (Ie, a PUCCH resource that is dynamically allocated by linking with PDCCH). In the 3GPP LTE / LTE-A system, PUCCH resources for transmission of CSI, SPS ACK / NACK, SR, etc. are explicitly semi-statically reserved to the UE by an upper layer signal. Hereinafter, for ACK / NACK transmission, a PUCCH resource dynamically determined in association with a PDCCH is specifically called a dynamic PUCCH resource or an implicit PUCCH resource, and semi-statically refers to a PUCCH resource explicitly configured by a higher layer signal. It is called a (semi-static) PUCCH resource or explicit PUCCH resource. In addition, a PUCCH resource for transmitting CSI is called a CSI PUCCH resource or a CSI resource, and a PUCCH resource for transmitting an SPS ACK / NACK is called an SPS ACK / NACK PUCCH resource or an SPS ACK / NACK resource, and is used for transmitting an SR. The PUCCH resource is called SR PUCCH resource or SR resource, and the PUCCH resource for transmitting ACK / NACK associated with PDCCH is called ACK / NACK PUCCH resource or ACK / NACK resource.

Referring to FIG. 5, PUCCH resources based on one cell ID may include DC subcarriers from remote subcarriers based on a direct current (DC) subcarrier (that is, a subcarrier mapped to f ₀ during a frequency upconversion process). Direction, CSI PUCCH resources, SPS ACK / NACK and SR PUCCH resources, and dynamic ACK / NACK PUCCH resources. In other words, PUCCH resources that are semi-statically configured by higher layer signaling are located outside of the UL transmission bandwidth and dynamically configured ACK / NACK PUCCH resources are higher than the semi-statically configured PUCCH resources. Located close to the center frequency. In this case, the closer to the center frequency, the larger the PUCCH resource index. In other words, the index of the PUCCH resource allocated to the PRB close to the center frequency is larger than the index of the PUCCH resource allocated to the PRB far from the center frequency. A plurality of PUCCH resources in the same PRB are indexed based on orthogonal sequence and / or cyclic shift.

Referring to Equation 2, the PUCCH resources for ACK / NACK is not previously allocated to each UE, the plurality of PUCCH resources are used by each of the plurality of UEs in the cell divided at each time point. Specifically, the PUCCH resources used by the UE to transmit ACK / NACK are dynamically determined based on the PDCCH carrying scheduling information for the PDSCH carrying corresponding downlink data. The entire region in which the PDCCH is transmitted in each DL subframe consists of a plurality of control channel elements (CCEs), and the PDCCH transmitted to the UE consists of one or more CCEs. The UE transmits ACK / NACK through a PUCCH resource linked to a specific CCE (for example, the first CCE) among the CCEs constituting the PDCCH received by the UE.

At each UE, ACK / NACK signals are transmitted through different resources consisting of different cyclic shifts (frequency domain codes) and orthogonal cover codes (time domain spreading codes) in a computer-generated constant amplitude zero auto correlation (CG-CAZAC) sequence. do. OC includes, for example, Walsh / Discrete Fourier Transform (DFT) orthogonal code. An orthogonal sequence (eg, [w0, w1, w2, w3]) can be applied in any time domain (after Fast Fourier Transform (FFT) modulation) or in any frequency domain (prior to FFT modulation). If the number of cyclic shifts (CS) is 6 and the number of OCs is 3, a total of 18 UEs may be multiplexed within the same physical resource block (PRB) based on a single antenna. In other words, PUCCH resources used for transmission of the ACK / NACK signal may be distinguished by OCC, CS (or CCS (CAZAC CS)) and PRB. If any one of OCC, CS, and PRB is different, it is regarded as another PUCCH resource. Can be.

6 shows an example of determining a dynamic PUCCH resource in a 3GPP LTE / LTE-A system.

Referring to FIG. 6, each PUCCH resource index corresponds to a dynamic PUCCH resource for ACK / NACK. The eNB transmits the DCI or fallback DCI according to the transmission mode configured in the UE to the UE on the PDCCH according to the channel situation. Fallback DCI refers to a DCI to be used for communication according to another transmission mode (hereinafter, referred to as a fallback mode) in which communication efficiency is lower than that of the corresponding transmission mode in case the channel state is not good and communication in accordance with the corresponding transmission mode is difficult. it means. Hereinafter, the DCI according to the transmission mode is referred to as TM dependent DCI, and the DCI for the fallback mode is referred to as fallback DCI. In addition, a DCI format defined for transmission of TM dependent DCI is called a TM dependent DCI format, and a DCI format defined for transmission of fallback DCI is called a fallback DCI format. Referring to Table 6, for example, it can be said that the DCI format 1A corresponds to the fallback DCI format. The UE may operate by switching to the fallback mode when detecting the fallback DCI. Or, if it is necessary to perform RRC reconfiguration, the UE may operate by switching to the fallback mode to eliminate the ambiguity problem that occurs during the RRC reconfiguration.

Referring to FIG. 6, the eNB may transmit scheduling information for the PDSCH to the UE on PDCCH of aggregation level 2 (L = 2) on n and n + 1 CCEs. The UE is configured in a specific transmission mode through higher layer signaling. Accordingly, the DCI format that can be transmitted to the UE is limited to a fallback DCI format (DCI format A of FIG. 6) and a TM dependent DCI (DCI format B of FIG. 6) according to the transmission mode configured for the UE. The UE attempts to decode the PDCCH candidate (s) according to the aggregation level according to DCI format A and DCI format B in the common search space and / or the UE specific search space, and thus uses the detected DCI format to decode the PDSCH. It demodulates and sends an ACK / NACK for this to the eNB using the PUCCH resource linked to the CCE of the PDCCH in which the DCI format is detected. At this time, since DCI format A and DCI format B are transmitted on the same CCE resources, they are linked to the same PUCCH resource m. Accordingly, the UE transmits the ACK / NACK associated with the DCI to the eNB using the PUCCH resource m in both the case of detecting the DCI of DCI format A and the case of detecting the DCI of DCI format B, and the eNB transmits the DCI format. In both the case of transmitting the DCI of A and the case of transmitting the DCI of DCI format B, the ACK / NACK associated with the corresponding DCI from the UE is received using the PUCCH resource m.

Specifically, the PUCCH resource index for transmission by two antenna ports p ₀ and p ₁ in the 3GPP LTE / LTE-A system is determined as follows.

Equation 5

Equation 6

Here, n ^{(1, p = p0)} _PUCCH represents an index (ie, a number) of PUCCH resources to be used by antenna port p ₀ , and n ^{(1, p = p1)} _PUCCH represents a PUCCH resource index to be used by antenna port p ₁ . N ⁽¹⁾ _PUCCH represents a signaling value received from a higher layer. N ⁽¹⁾ _PUCCH corresponds to the position where the dynamic PUCCH resource starts among the PUCCH resources of the cell. n _CCE corresponds to the smallest value among the CCE indexes used for PDCCH transmission. For example, when the CCE aggregation level is 2 or more, the first CCE index among the indexes of the plurality of CCEs aggregated for PDCCH transmission is used for determining the ACK / NACK PUCCH resource. That is, a PUCCH resource used for transmission of ACK / NACK for a PDCCH or a PDSCH according to the PDCCH is determined in association with a DL CCE, which is called a dynamic CCE-to-AN linkage.

According to the 3GPP LTE / LTE-A system to date, all UEs served in a specific cell receive information indicating the same N ⁽¹⁾ _PUCCH from the eNB of the cell in semi-static manner. . In other words, according to the existing 3GP LTE / LTE-A system, UEs located in a specific cell share dynamic PUCCH resources after N ⁽¹⁾ _PUCCH , and each of the dynamic PUCCH resources is commonly applied to the specific cell. Linked with CCE indexes respectively. When the cell where the UE receives the downlink signal and the cell where the UE transmits the uplink signal are the same, the UE may determine the dynamic PUCCH resource without any problem using only N ⁽¹⁾ _PUCCH provided in a cell-specific manner. However, in the case of CoMP in which a cell (downlink cell) that transmits a downlink signal to a UE and a cell (uplink cell) in which the UE transmits an uplink signal may vary, PUCCH resources configured for each cell may vary. . Hereinafter, a corresponding node of the downlink cell is called a transmission point, and a corresponding node of the uplink cell is called a reception point. When the transmission point and the reception point are different, the index of the PUCCH resource linked to the CCE of the PDCCH received by the downlink cell may be a different index in the uplink cell, and the PUCCH resource may be in the CCE of another PDCCH of the uplink cell. It may be linked. In addition, since semi-static PUCCH resources are independently reserved for each cell, the start position of the dynamic PUCCH resource of the downlink cell and the start position of the dynamic PUCCH resource of the uplink cell may be different, in which case one N ⁽¹⁾ _PUCCH alone cannot determine the PUCCH resources linked to a specific CCE. Accordingly, the present invention provides a method for efficiently operating the PUCCH resources under a CoMP situation in which the downlink cell and the uplink cell may be different.

The present invention proposes to configure additional dynamic PUCCH resources separately from existing dynamic PUCCH resources. In other words, the present invention proposes to configure a collection of additional dynamic PUCCH resources UE-specific or UE group-specific or transmission mode-specifically apart from the existing collection of cell-configured existing dynamic PUCCH resources. For example, an eNB may determine a UE-specific or UE group-specific or transmission mode specific PUCCH resource index offset value separately from a cell-specific PUCCH resource index offset value (eg, N ⁽¹⁾ _PUCCH ). The additional dynamic PUCCH resources can be configured by sending to the UE.

7 illustrates an example of determining a dynamic PUCCH resource according to an embodiment of the present invention, and FIG. 8 illustrates an example of CoMP to which the present invention can be applied.

For example, the eNB may be UE specific or UE group specific or transmission mode specific PUCCH resource separately from the PUCCH resource index offset value (eg, N ⁽¹⁾ _PUCCH ) provided cell specific for Cell ^1. The additional dynamic PUCCH resources can be configured by sending an index offset value K to the UE.

By the higher layer signal transmitted by the eNB, the UE configured to perform CoMP attempts to decode the DCI according to the TM dependent DCI format and the fallback DCI format in the corresponding search space. In FIG. 7 and FIG. 8, DCI format B, which is a TM dependent DCI format, corresponds to a DCI format defined for CoMP. The UE ACK / NACK for the TM dependent DCI using a PUCCH resource linked to a CCE index (eg, CCE n) of a PDCCH carrying a TM dependent DCI (DCI format B) or a fallback DCI (DCI format A). Or transmits ACK / NACK for PDSCH according to the TM dependent DCI to the eNB. In this case, when the UE detects a TM dependent DCI corresponding to CoMP, the PUCCH linked to the CCE index n of the PDCCH carrying the TM dependent DCI among the dynamic PUCCH resources configured separately from the existing dynamic PUCCH resources Determine your resources. For example, referring to FIG. 7, when the UE detects a TM dependent DCI, PUCCH resource 'm + K' linked to the CCE index n of PUCCH resource B, which is a collection of PUCCH resources configured separately for CoMP, is determined. The corresponding ACK / NACK is transmitted to the eNB. On the other hand, when the UE needs to switch to the fallback mode, the PUCCH resource linked to the CCE index n of the PDCCH carrying the fallback DCI is determined among the PUCCH resource A which is a collection of existing dynamic PUCCH resources. For example, the UE transmits the corresponding ACK / NACK to the eNB using the PUCCH resource m linked to the CCE index n among the PUCCH resource B. In other words, the UE may receive a plurality of PUCCH resource index offset values from the eNB, and determine the PUCCH resources by applying different offset values depending on whether to detect the fallback DCI or the TM dependent DCI. Referring to FIG. 7, a UE operating in a fallback mode configures a PUCCH resource index offset to N ⁽¹⁾ _PUCCH to determine dynamic PUCCH resources, and a UE operating in CoMP mode sets a PUCCH resource index offset to 'N ^(1). Configure _PUCCH + K 'to determine dynamic PUCCH resources.

In FIG. 7, a value indicating a relative position based on N ⁽¹⁾ _PUCCH indicating a start position of an existing dynamic PUCCH resource among PUCCH resources of a corresponding cell is an offset value indicating a start position of a dynamic PUCCH resource separately configured according to the present invention. The case used as is illustrated. However, a value indicating an absolute starting position rather than a relative value based on N ⁽¹⁾ _PUCCH may be used as an offset value indicating a starting position of a dynamic PUCCH resource separately configured according to the present invention.

Referring to FIG. 8, the UE may transmit an uplink UCI associated with the PDCCH using a PUCCH resource determined according to the above-described embodiment of the present invention toward the same cell 1 that has received the PDCCH.

The above-described embodiment of the present invention may be applied to a DCI format for PDSCH transmission, that is, a DC grant format for UL grant as well as a DCI format for UL grant. Referring to FIG. 8, the UE of the present invention may transmit ACK / NACK information for the DC grant format for the DL grant to cell 1 using the PUCCH resource determined according to the above-described embodiment of the present invention. However, the UE may transmit a PUSCH according to the DCI format for DL grant toward cell 2 which is a cell different from cell 1.

In addition to the PUCCH resource index, parameters related to ACK / NACK transmission such as a PUCCH / PUSCH DeModulation Reference Signal (DMRS) sequence, a power control setting, a PUCCH payload sequence, a hopping pattern, and the like may also change according to the detected DCI format. . In other words, the eNB determines parameters related to ACK / NACK transmission such as a PUCCH / PUSCH DeModulation Reference Signal (DMRS) sequence, a power control setting, a PUCCH payload sequence, a hopping pattern, and the like for the fallback DCI format. Separately, a parameter for the TM dependent DCI format may be configured and transmitted to the UE. The UE may transmit the PUCCH by applying the parameter for the fallback DCI when detecting the fallback DCI format, and transmit the PUCCH by applying the parameter for the TM dependent DCI when detecting the TM-dependent DCI format. For example, the eNB may transmit a DMRS sequence, a power control parameter, or the like, to a DCI format (eg, DCI format 0) for a fallback PUSCH transmission and a DCI format (eg, to a MIMO transmission) for TM-dependent PUSCH transmission (eg, DCI format 4) may be configured separately for each and signaled to the UE. The UE may perform PUSCH transmission by applying a DMRS sequence, a power control parameter, etc. corresponding to the detected DCI format among preconfigured DMRS sequences, power control parameters, and the like.

Embodiments of the present invention can also be applied to carrier aggregation. Carrier aggregation (CA) (or bandwidth aggregation) refers to a larger uplink / downlink bandwidth by combining a plurality of uplink / downlink frequency blocks to use a wider frequency band than a frequency band operating on one carrier. Speaks technique to use. A typical wireless communication system performs data transmission / reception through one downlink (DL) band and one uplink (UL) band corresponding thereto (frequency division duplex (FDD) mode). Or a predetermined radio frame divided into an uplink time unit and a downlink time unit in a time domain, and perform data transmission / reception through uplink / downlink time units. time division duplex (TDD) mode). The eNB and the UE transmit and receive the scheduled data and / or control information in units of a predetermined time unit, for example, a subframe (SF). Unlike a single carrier technology in which one DL band and one UL band corresponding thereto are used for communication, carrier aggregation refers to a plurality of uplink / downlink frequency blocks that are used to use a wider frequency band. This technique uses a larger uplink / downlink bandwidth. In the carrier aggregation technology, DL and / or UL communication is performed using a plurality of carrier frequencies, an OFDM that performs DL or UL communication by putting a fundamental frequency band divided into a plurality of orthogonal subcarriers on one carrier frequency It is distinguished from technology. Each of the plurality of carriers aggregated is called a component carrier (CC). Each CC may be adjacent to each other or non-adjacent in the frequency domain, and the bandwidth of each CC may be determined independently. Asymmetrical carrier aggregation in which the number of UL CCs and the number of DL CCs are different is also possible. Here, the UL CC and the DL CC are also called UL resources and DL resources, respectively.

The 3GPP LTE-A system uses the concept of a cell to manage radio resources. A cell is defined as a combination of DL resources and UL resources, that is, a combination of a DL CC and a UL CC. The cell may be configured of DL resources alone or a combination of DL resources and UL resources. If carrier aggregation is supported, the linkage between the carrier frequency of the DL resource (or DL CC) and the carrier frequency of the UL resource (or UL CC) is indicated by system information. Can be. For example, a combination of a DL resource and a UL resource may be indicated by a system information block type 2 (SIB2) linkage. In the case of FDD, since the UL operating band and the DL operating band are different from each other, different carrier frequencies are linked to form one cell, and the SIB2 linkage uses a different frequency from that of the DL CC to which the UE is connected. It is indicated as the frequency of. In other words, in the case of FDD, the DL CC constituting one cell and the UL CC linked with the DL CC operate at different frequencies. In the case of TDD, since the UL operating band and the DL operating band are the same, one carrier frequency forms one cell, and the SIB2 linkage uses the same frequency as that of the DL CC to which the UE is connected. It is indicated as In other words, in the case of TDD, the DL CC constituting one cell and the UL CC linked with the DL CC operate at the same frequency. Here, the carrier frequency means a center frequency of each cell or CC. A cell operating on a primary frequency is referred to as a primary cell (PCell) or a PCC, and a cell operating on a secondary frequency (or SCC) is referred to as a secondary cell (SCell). Or SCC. PCell refers to a cell used by a UE to perform an initial connection establishment process or to initiate a connection reestablishment process. PCell may refer to a cell indicated in the handover process. As another example, the PCell may refer to a DL CC which is initially synchronized with a UE by receiving a DL synchronization signal (SS) and an UL CC linked to the DL CC. In the downlink, the carrier corresponding to the PCell is called a downlink primary CC (DL PCC), and the carrier corresponding to the PCell in the uplink is called a UL main CC (DL PCC). SCell refers to a cell that is configurable after RRC (Radio Resource Control) connection establishment is made and can be used to provide additional radio resources. Depending on the capabilities of the UE, the SCell may form a set of serving cells for the UE with the PCell. The serving cell may be called a serving CC. The carrier corresponding to the SCell in downlink is called DL Supplementary CC (DL SCC), and the carrier corresponding to the SCell in uplink is called UL Supplementary CC (UL SCC). In case of the UE that is in the RRC_CONNECTED state but no carrier aggregation is configured or does not support carrier aggregation, there is only one serving cell configured with a PCell. On the other hand, in the case of a UE configured in the RRC_CONNECTED state and configured with carrier aggregation, one or more serving cells may exist, and the entire serving cell may include one PCell and one or more SCells. For carrier aggregation, after the initial security activation process is initiated, the network may configure a UE in which carrier aggregation is supported by adding one or more SCells to an initially configured PCell during a connection establishment process. However, even if the UE supports carrier aggregation, the network may configure only the PCell for the UE without adding the SCell.

For reference, the term cell used in carrier aggregation is distinguished from a term cell which refers to a certain geographic area where communication service is provided by one eNB or one antenna group. The downlink signal of a specific cell, which refers to a coverage of a communication service, means a signal transmitted by an eNB or an antenna group of the specific cell to a UE and is an uplink of the specific cell. The signal refers to a signal transmitted by the UE to an eNB or an antenna group of the specific cell. In contrast, a downlink / uplink signal of a cell of a carrier aggregation refers to a radio signal transmitted / received using resources constituting the cell. In order to distinguish a cell indicating a certain geographic area from a cell of a carrier aggregation, a cell of a carrier aggregation is hereinafter referred to as a CC, and a cell of the geographic area is simply a cell. Hereinafter, embodiments of the present invention will be described.

In the case of communication using a single carrier, since only one serving CC exists, the PDCCH carrying the UL / DL grant and the corresponding PUSCH / PDSCH are transmitted on the same CC. In other words, in the case of FDD under a single carrier situation, the PDCCH for the DL grant for the PDSCH to be transmitted in a specific DL CC is transmitted in the specific CC, and the PDCCH for the UL grant for the PUSCH to be transmitted in the specific UL CC is specified in the specific CC. It is transmitted on the DL CC linked with the UL CC. In contrast, in a multi-carrier system, since a plurality of serving CCs may be configured, UL / DL grants may be allowed to be transmitted in a serving CC having a good channel condition. As such, when the CC carrying the UL / DL grant as scheduling information and the CC on which the UL / DL transmission corresponding to the UL / DL grant is performed are different, this is called cross-carrier scheduling (CCS). Hereinafter, a CC on which a PDCCH carrying a UL / DL grant is transmitted is called a scheduling CC, and a CC on which a PUSCH / PDSCH according to the UL / DL grant is transmitted is called a scheduled CC. When a CC is used to transmit a PDCCH carrying its own scheduling information, the CC becomes a scheduling CC and a scheduled CC. In 3GPP LTE-A system, aggregation of multiple CCs and CCS operation based on the same may be supported for data rate improvement and stable control signaling. The PCC may carry scheduling information for itself and the SCC, and the SCC may carry scheduling information for itself and another SCC. However, it is not allowed in principle for the SCC to carry scheduling information on the PCC. Although a plurality of PDCCHs may be transmitted through a scheduling CC, PUCCH transmissions associated with the plurality of PDCCHs are performed only on the PCC. Accordingly, the PCC is reserved for the PUCCH resources associated with the PCC and the PUCCH resources associated with the SCC.

If PUCCH transmission is allowed only on the PCC, since both the CCS and the non-CCS can transmit the UCI only on the PCC, PUCCH resources associated with the PCC and PUCCH resources associated with the SCC are reserved on the PCC. For example, in the case of CCS, assuming that the PCC is a scheduling CC of another SCC (s), the PCC has PUCCH resource (s) for PDSCH (s) transmitted through the PCC according to the PDCCH transmitted through the PCC. And PUCCH resource (s) for PDSCH (s) via SCC (s) according to the PDCCH transmitted via the PCC is implicitly reserved by the CCE indexes of the PDCCHs. In the case of non-CCS in which scheduling information of the corresponding CC is transmitted only through the corresponding CC, the PUCCH resource (s) associated with the PDCCH (s) transmitted through the PCC is implicitly indicated by the CCE index (es) of the PDCCH (s). The PUCCH resource (s) associated with the PDCCH (s), which are reserved and sent over the SCC, are reserved by explicit signaling from the eNB. For example, the eNB provides semi-statically the PUCCH resource indexes for the SCC to the UE through higher layer signaling, and dynamically allocates the PUCCH resource index to be used for actual ACK / NACK transmission by using a predetermined field in the DCI format. Can be directed. For example, the TPC field in the DCI format may be used as an ACK / NACK Resource Indicator (ARI) indicating one of a predetermined number of PUCCH resources explicitly configured.

CoMP operation may be performed in both carrier aggregation of CCS and carrier aggregation of non-CCS. In the present invention, when carrier aggregation and CoMP are configured together, it is proposed to explicitly or implicitly reserve a PUCCH resource for CoMP separately from the existing PUCCH resources reserved for PCC and SCC in the PCC. When CoMP is performed on a plurality of carrier aggregated CCs, a PUCCH resource region (also referred to as a PUCCH resource set or a PUCCH resource group) for CoMP is separately provided for each CC. In order to be able to operate, the eNB may transmit CoMP PUCCH resource position information for each CC (for example, information indicating a PUCCH resource start position) to the UE. For example, when CoMP is applied to N CCs, the eNB may signal N PUCCH resource index offset values to the UE. When the UE detects the fallback DCI format, the UE determines a PUCCH resource among existing PUCCH resources, and when detecting a TM dependent DCI, the new PUCCH resources separately reserved for the CC based on the CoMP PUCCH resource location information for each CC. The PUCCH resource to be used for UCI transmission associated with the corresponding CC may be determined.

If the fallback DCI format is called DCI format 1A, the TM dependent DCI format is called DCI format X, the DCI format detected at PCC is called PCC DCI format, and the DCI format detected at SCC is called DCI format at SCC DCI format. In case of carrier aggregation of CCS, PUCCH resources may be reserved / determined in the PCC as follows. At this time, the PCC PUCCH resource means a PUCCH resource on the PCC.

● PCC DCI Format 1A-> Existing PCC PUCCH Resource: CCE Linkage

PCC DCI format X-> new PCC PUCCH resources: offset signaling and CCE linkage

● SCC DCI Format 1A-> Existing PCC PUCCH Resource: CCE Linkage

SCC DCI format X-> new PCC PUCCH resources: offset signaling and CCE linkage

For reference, when simultaneous transmission of a PUSCH and a PUCCH is not allowed and a transmission time of a PUSCH collides with a transmission time of a PUCCH (that is, a PUSCH transmission and a PUCCH transmission are simultaneously configured), the UCI is piggybacked on the PUSCH. May be sent. In other words, in a UE configured such that simultaneous transmission of PUSCH and PUCCH is not allowed, when the transmission time of the PUSCH collides with the transmission time of the PUCCH, the UE drops the PUCCH transmission and transmits uplink data and UCI to the PUSCH. Send multiplexed.

In case of carrier aggregation of non-SCC, PUCCH resources for SCC may be explicitly configured by higher layer (eg, RRC) signaling. However, as in CCS, only the PUCCH resource region for CoMP may be signaled using the PUCCH resource index offset, and actual individual PUCCH resources may be dynamically allocated. That is, the dynamic PUCCH resource for CoMP for the SCC can be secured and operated in the PCC separately from the dynamic PUCCH resource region of the PCC. The individual mapping of the PDCCH through the SCC and the PUCCH resources reserved on the PCC for CoMP of the SCC may be based on the CCE index of the CoMP dependent DCI format carried by the PDCCH.

In the PUCCH format 3, PUCCH resource allocation for a CoMP UE operating in CoMP mode and a normal UE operating in a transmission mode other than CoMP mode may be made according to the above-described embodiment of the present invention. It may be achieved by dividing the PUCCH resource set previously reserved for three. For example, a generic UE selects one PUCCH resource among PUCCH resources in a reserved PUCCH resource set to perform PUCCH format 3 transmission, while a CoMP UE performs a generic UE among PUCCH resources in the PUCCH resource set. One or more of the PUCCH resources not used may be specified and used. If four PUCCH resources are reserved for PUCCH format 3 by RRC signaling, two PUCCH resources of the four PUCCH resources are used as PUCCH resources for existing PUCCH transmission, and the other two are new transmissions ( For example, it may be used as a PUCCH resource for CoMP). Alternatively, as another example, a plurality of PUCCH resource sets composed of four PUCCH resources are configured, a specific set is used as PUCCH resources for existing transmission, and other resource sets are used as PUCCH resources for newly defined transmission. It is also possible. At this time, the distinction of each of the plurality of PUCCH resource sets or the linkage to the PUCCH resource set to be actually used may be implicitly or explicitly determined according to the DCI format, CCE index, antenna port, aggregation level, RRC signaling, and the like. The current ARI consists of 2-bits (ie, four states) to indicate one of four PUCCH resources. The ARI can be used for general PUCCH resource indication or new PUCCH resource indication according to DCI format. . For example, a PUCCH resource set 1 of {A, B, C, D} for a general transmission mode and a PUCCH resource set 2 of {A ', B', C ', D'} for a CoMP mode are configured from an eNB. Upon receiving the DCI format of the normal transmission mode, the received UE determines that the 2-bit ARI in the DCI format of the normal transmission mode indicates one of PUCCH resource set 1, and thus, among the A, B, C, and D according to the ARI. If one is selected and transmits PUCCH format 3 and detects a DCI format of CoMP mode, it is determined that the ARI in the DCI format of the CoMP mode indicates one of PUCCH resource sets 2, and according to the ARI, A 'and B' are determined. One of, C ', and D' may be selected to transmit PUCCH format 3. On the other hand, two of the four states 00, 01, 10, 11 of the ARI (eg, 00, 01) are used for general PUCCH resource indication purposes and the other two states (eg, 10, 11) are new. It may be defined to be used for PUCCH resource indication.

When the UE is configured in CoMP mode, the UE switches or selects PUCCH resources based on CoMP mode configuration signaling. That is, when the UE configured in the CoMP mode detects the DCI format for CoMP, the UE uses the PUCCH resources reserved for CoMP, and the UE configured in the transmission mode other than the CoMP mode or the UE detecting the fallback DCI format even when configured in the CoMP mode. Can be operated to use existing dynamic PUCCH resources.

<Selection of existing or new PUCCH resources according to CCE index>

Meanwhile, dynamic PUCCH resources may be divided into various resource regions according to a purpose, and one resource region may be selected and used according to a DCI format or a transmission mode or higher layer signaling. For example, the eNB configures two types of PUCCH resource regions (eg, PUCCH resource region 1 and PUCCH resource region 2) in advance to signal to the UE, and transmits corresponding PUCCH among the PUCCH resource region 1 and PUCCH resource region 2. PUCCH resources to be used by the UE at this point may be implicitly signaled to the UE using the CCE index of the DCI format for the DL grant. That is, the UE is semi-statically allocated to PUCCH resource region 1 and PUCCH resource region 2, and the PUCCH resource to be used at a specific PUCCH transmission time is determined according to the CCE index of the PDCCH associated with the specific PUCCH transmission time. It may be determined in the PUCCH resource region 2. For example, if the odd CCE index is previously defined as being linked to PUCCH resource 1 and the even CCE index is linked to PUCCH resource 2, the UE decodes the DL grant and depends on whether the odd / even number of the obtained CCE index is odd or even. It is possible to determine which PUCCH resource region from among 1 and PUCCH resource region 2 to select a PUCCH resource. Which individual PUCCH resources in the corresponding PUCCH resource region are to be used may also be implicitly / dynamically determined by the CCE index. Assuming that PUCCH resources related to CoMP are allocated to PUCCH resource 2, the eNB maps DL grants of CoMP UEs to CCEs of even indexes to prevent CoMP UEs and regular UEs from sending ACK / NACK using the same PUCCH resources. can do. As another example, the CCE indexes 1 to 50 may be linked to the PUCCH resource region 1 in order, and the CCE indexes 51 to 100 may be linked to the PUCCH resource region 2. Assuming that PUCCH resources related to CoMP are allocated to PUCCH resource region 2, the eNB maps the DL grant of the CoMP UE to one or more CCEs among the CCEs having CCE indexes 51 to 100 so that the CoMP UE and the general UE share the same PUCCH resources. It is possible to prevent the transmission of the ACK / NACK. The UE when upon detection of a value which of the CCE index 51-100 as n _CCE selecting a PUCCH resource in the PUCCH resource region 2 detects a value of one of the CCE index 1 to 50 as n _CCE the PUCCH resource in the PUCCH resource region 1 Can be configured to select.

<Selection of existing or new PUCCH resources by aggregation level or search space>

The PUCCH resource region may be selected according to the CCE aggregation level. That is, the PUCCH resource region may be determined by linking a specific aggregation level with a specific CCE index. For example, if the eNB transmits DCI on the aggregation of CCEs corresponding to a high aggregation level (eg, aggregation level 4 or 8), this means that the downlink channel condition is not good, so that the UE is in fallback mode at a high aggregation level. It is likely to work. Thus, at high aggregation levels (eg aggregation level 4 or 8), PUCCH resources are selected in the existing PUCCH resource region according to existing PUCCH resource linkage rules, and at low aggregation levels (eg aggregation level 1 or 2). According to the present invention, the eNB and the UE may be configured to select a PUCCH resource in a new PUCCH resource region according to a newly introduced PUCCH resource linkage rule. Alternatively, a PUCCH resource region and a corresponding PUCCH resource index may be obtained depending on the value of a specific field of the DCI format.

Due to the overlap of the search space according to the aggregation level, a situation may occur in which the UE recognizes that the DCI is transmitted at an aggregation level other than the aggregation level transmitted by the eNB. For example, assuming that PDCCH of aggregation level 1 or 2 is linked to a new PUCCH resource and aggregation levels 4 or 8 are linked to an existing PUCCH resource, although the eNB sent DCI at aggregation level 4, the UE did not have the aggregation level. In 2, a case of successful decoding of the DCI may occur. In this case, the eNB expects to receive the UCI using the existing PUCCH resources. Since the UE transmits the UCI using the new PUCCH resources, the eNB cannot effectively receive the UCI. In order to solve this problem, a search space of a PDCCH to be linked to an existing PUCCH resource region and a search space of a PDCCH to be linked to a new PUCCH resource region may be configured differently. Alternatively, even if the UE succeeds in decoding the PDCCH at any aggregation level, it is also possible for the UE to determine the correct aggregation level by attempting to decode all other possible aggregation level (s). When the UE succeeds in decoding the PDCCH at various aggregation levels, the UE may determine the DCI received through the high aggregation level PDCCH as a valid DCI. This is because the eNB transmits the PDCCH at a low aggregation level, but the UE does not succeed in decoding the PDCCH at a high aggregation level. Both the above methods can help the UE to resolve the collision problem of PUCCH resources or the collision of CCEs by enabling the UE to check the exact aggregation level.

Or, it may be connected to other PUCCH resources explicitly or implicitly according to a specific antenna port, layer, and carrier.

<Operating with single DCI format only in uplink>

In case of uplink transmission (eg, signal transmission through PUSCH), only DCI format 0 may be used for scheduling of the uplink transmission. In this case, DCI format 0 is used for operations such as UL transmission to UL CoMP, a UL cell different from the DL cell. If only DCI format 0 is used for PUSCH transmission, the above-described determination of existing PUCCH resources or new PUCCH resources based on the DCI format according to the present invention cannot be applied. Thus, in this case, the UE decides whether DCI format 0 is related to normal operation or special operation (e.g. fallback operation) in order to determine whether to use an existing PUCCH resource or a new PUCCH resource. It is required to find out. This eNB can inform the UE. For example, the eNB may place DCI format 0 in search space A (eg, USS) or CCE index A range when the UE needs to perform normal operation or at a specific aggregation level (eg, aggregation). By using only level 1 or 2), the UE is informed that the DCI format 0 is related to normal operation, and when the UE needs to perform special operation, DCI format 0 is searched for search space B (e.g., CSS) or CCE index. Positioning in the B range or using only a specific aggregation level (eg, aggregation level 4 or 8) may inform the UE that the DCI format 0 is for special operation.

<Operating with multiple DCI formats on uplink>

On the other hand, when DCI format 0 is used as the DCI format for fallback DCI and DCI format 4 is used as the DCI format for TM-dependent DCI, the UE determines PUCCH resource region 1 when DCI format 0 is detected and PUCCH when DCI format 4 is detected. It can be implemented to use resource zone 2.

<DL CoMP + UL CoMP Association Grant>

In the CoMP scenario, the PUCCH resource region 1 and the PUCCH resource region 2 according to the present invention are configured for different cells or reception points. The PUCCH resource region 1 and the PUCCH resource region 2 may be configured based on different cell IDs or may be configured based on the same cell ID and include different PUCCH resources.

The PUCCH resource region 1 and the PUCCH resource region 2 may be prevented from generating physically colliding resources by different PUCCH resource index offsets. When the CoMP mode is configured or indicated among the above-described embodiments of the present invention, an embodiment for using CoC PUCCH resources for CoMP may apply CoMP to PUCCH transmission. Hereinafter, PUCCH transmission to which CoMP is applied is referred to as PUCCH CoMP. In particular, in order to allow the PUCCH CoMP to operate naturally in conjunction with the DL CoMP operation, the present invention does not apply CoMP to PUCCH transmission using CCE and PUCCH resources that are mutually linked by an existing CCE-to-AN linkage. An embodiment of applying CoMP only to PUCCH transmission using dynamic PUCCH resources reserved for CoMP is proposed. Of course, PUCCH CoMP may operate independently of DL CoMP, but PUCCH CoMP may be activated in association with DL CoMP by signaling from eNB. DL CoMP and UL CoMP may be configured in various combinations by signaling from eNB. For example, the following combinations are possible.

DL CoMP (PDSCH) + UL CoMP (all PUCCH)

DL CoMP (PDSCH) + UL CoMP (only CoMP PUCCH)

DL CoMP (PDSCH) + UL CoMP (All PUCCH + PUSCH)

4.DL CoMP (PDSCH) + UL CoMP (Only CoMP PUCCH + PUSCH)

Here, "all PUCCH" means that PUCCH using any PUCCH resource may be transmitted to a point different from the PDSCH transmission point, regardless of whether it is an existing PUCCH resource or a PUCCH resource for CoMP, and "only CoMP PUCCH resource". Means that a PUCCH using only PUCCH resources configured for CoMP can be used for PUCCH transmission to a point different from the PDSCH transmission point.

In PUCCH CoMP, ACK / NACKs may be transmitted on PUCCH with the same / different cyclic shift (CS) / orthogonal sequence (OCC) applied on the same RB or transmitted with different CS / OCC on the same RB and transmitted on PUCCH. have. That is, in case of PUCCH CoMP, a plurality of ACK / NACKs may be transmitted through one PUCCH in one of the following forms.

1. Same PUCCH RB + Same CS / OCC

2. Same PUCCH RB + different CS / OCC

3. Different PUCCH RB + same CS / OCC

4. Different PUCCH RB + Different CS / OCC

The present invention in which PUCCH resources are separately managed by the PUCCH resource index offset may be applied to the PUCCH transmitted in the form of Nos. 2, 3 and 4 of them. As in No. 4, a plurality of ACK / NACKs may be separately mapped to PUCCH resources that are orthogonal to each other. In the case where a plurality of ACK / NACKs are multiplexed using the same CS / OCC in the same RB as in step 1, the ACK / NACKs are difficult to distinguish from each other even by the PUCCH resource index offset according to the present invention. Therefore, in case 1, even though ACK / NACKs are transmitted in the same RB by extending to a spatial domain, the above-described multiple PUCCH resource reservation schemes according to the present invention can be effectively applied by transmitting them through different layers. .

<Applicability to PUCCH / PUSCH CoMP (DPS) of the Invention>: Another Cell ID

9 illustrates another example of determining a dynamic PUCCH resource according to an embodiment of the present invention. In particular, FIG. 9 illustrates a PUCCH resource linkage / reservation when uplink dynamic point selection (DPS) is activated.

The uplink DPS involves an operation of changing the target receiving point of the uplink transmission from time to time. If the target receiving point has a cell ID different from the existing cell ID, PUCCH and PUSCH transmission corresponding to the changed target cell should be performed. Since the PUCCH transmission is performed with resource allocation in association with the cell ID, the UE needs to generate the PUCCH resources differently according to which point the PUCCH is transmitted. Therefore, the UE should be configured to generate the PUCCH resource according to the cell ID of the target receiving point to transmit the PUCCH. On the other hand, since the path loss varies depending on the target receiving point, the power control offset may be set differently according to the target receiving point. Therefore, the present invention proposes to control the UL power for each reception point. If the collection of points that the UE can dynamically select is called a DPS set, for example, the UE must know the PUCCH / PUSCH / SRS power control offset for each cell ID included in the DPS set, and the UE must know every uplink transmission moment. It is possible to determine the power control offset of which channel of which cell each time and apply the determined power control offset to uplink transmission to the corresponding cell. The eNB pre-configures a plurality of power control offsets to signal to the UE and dynamically or explicitly indicates among the plurality of power control offsets to enable the UE to apply the power control offset to perform uplink transmission. Can be. Alternatively, the UE may select one power control offset from the plurality of power control offsets according to a predetermined condition and apply it to uplink transmission. The UE may be configured to apply this operation to a PUCCH resource reserved for CoMP when CoMP dependent DCI detects it. Referring to FIG. 9, a PUCCH resource reserved for CoMP may be reserved by a PUCCH resource index offset (K or L) for an existing dynamic PUCCH resource from one cell's point of view, and further, when UL DPS is performed. In the PUCCH resource index offset may be configured for each target receiving point.

In FIG. 9, a value indicating a relative position calculated on the basis of N ⁽¹⁾ _PUCCH indicating a start position of a dynamic PUCCH resource of a specific cell (cell of RX point 1 ⁾ is determined according to the present invention. The case is used as an offset value (K, L) indicating the starting position. However, a value indicating an absolute starting position rather than a relative value based on N ⁽¹⁾ _PUCCH of a specific cell may be used as an offset value indicating a starting position of a dynamic PUCCH resource separately configured according to the present invention.

<Applicability to PUCCH / PUSCH CoMP (DPS) of the Invention>: Same Cell ID

10 shows another example of CoMP to which the present invention can be applied.

A DPS set may be configured that includes a number of receiving (RX) points but includes an RRH having the same cell ID as the eNB. If all of the receiving points in the DPS set have the same cell ID, all the receiving points in the DPS set may share the same PUCCH resources that the PUCCH is transmitted toward different receiving points.

However, in consideration of the change in the UL transmission power level as the distance from the UE varies according to the reception point, PUCCH resources using similar UL transmission power may be collected and allocated to each reception point. In this case, as shown in FIG. 9, a PUCCH resource region may be configured for each reception point, and the PUCCH resource region for each reception point may be divided by a PUCCH resource index offset. An existing DCI field such as CIF may be reused or a new DCI format may be defined and configure an indication field in the new DCI format to indicate to the UE which receiving point is the target point. The proposal of the present invention in which PUCCH resources are determined depending on the DCI format can also be applied here. For example, if a DCI format is defined for each reception point or a DCI format of the same length is used for all reception points, but if it is actually decoded, there is an indication field indicating what the target reception point is, and thus a PUCCH resource. It is possible for the area to be determined.

Multiple PUCCH resource regions are preconfigured and one of them is dynamically indicated (DCI format + CIF combination)

In the 3GPP LTE system, the UE is configured to blind decode up to two DCI formats according to a transmission mode. In this case, the UE will basically perform blind decoding on the fallback DCI format (eg, DCI format 1A) and TM dependent DCI format. The present invention allows the UE to perform a predetermined operation when a DCI format or other newly introduced DCI format designated to achieve a special purpose such as CoMP is detected. The cell selection parameter (s), such as which UE to perform UL transmission to, which cell to target to perform UL transmission, and which cell ID to use to perform UL transmission, are previously determined. Can be specified. In addition, the UE selects PUSCH transmission parameter (s) such as which PUSCH DMRS is to be used, selection of SRS transmission parameter (s) such as which sequence or RB is to be transmitted by the SRS, and which resource (CS) Selection of PUCCH transmission parameter (s), such as whether to use / OCC, RB, hopping, cell ID), etc. may be specified in advance. The parameter set is predefined and the UE can be configured to use the designated parameter set according to the DCI format. Here, the eNB may designate a plurality of parameter sets to the UE in advance by higher layer (eg, RRC) signaling, and allow the UE to select one or some of the plurality of parameter sets for use in UL transmission. have. If several parameter sets are configured by higher layer signaling, the UE may be configured to use the parameter set connected to the specific DCI when a specific DCI is detected. If the DCI format for the plurality of parameter sets is one, the UE may be configured to select one of the plurality of parameter sets by using additional information included in the DCI format. That is, parameter sets reserved for the DCI format are determined according to the DCI format, and among them, the parameter set used for the actual transmission can be dynamically indicated to the UE by the DCI transmitted through the PDCCH. Information indicating a parameter set to be applied to actual UL transmission among the reserved parameter sets may be transmitted from the eNB to the UE by reusing the CIF introduced for carrier aggregation. In carrier aggregation, the CIF is used to indicate which CC the corresponding DCI carries scheduling information. The CIF may be used to indicate a parameter set instead of indicating a CC. When the CIF is used for indicating a parameter set other than the CC, the CIF may be used as a kind of activation signal. For example, suppose the DCI format for CoMP is DCI format X. If CoMP is configured, PUCCH resources associated with DCI format X will be reserved in advance and parameters related to DCI format X will also be preconfigured. However, the PUCCH resources and parameters associated with this DCI format X are actually reserved only without being used, and when the DCI format X is detected by the UE, the reserved PUCCH resources and parameters are used. That is, it can be seen that a reserved PUCCH resource or parameter is activated by an additional field of DCI such as CIF along with DCI format X. The PUCCH resource region may be implicitly determined according to which subframe instead of CIF. For example, when a subframe in which PUCCH resources are heavily reserved for CoMP is periodically configured, when the eNB informs the UE of a start position and a configuration period of a subframe in which CoMP is highly reserved, the UE subframe of the period In CoMP PUCCH resources can be used, and other subframes can use existing PUCCH resources.

Meanwhile, an indication signal separate from the DCI may be used to indicate which of the reserved resources or parameters will be used. For example, the eNB may imply the UE that resources and parameters previously reserved are used by transmitting DCI format X, and may inform the UE through a separate indication signal of which resource and parameter should be used. . When the UE detects DCI format X, it can be known that resources and parameters previously reserved can be used, and performs UL transmission using any of the previously reserved resources and parameters based on the indication signal. I can see if I have to.

When the UE receives the PDSCH in DL cell 1 and transmits the PUCCH for the PDSCH toward UL cell 1 which is the same point as the DL cell 1, the UE uses the PUCCH resource connected to the CCE of the DL cell 1 PUCCH may be transmitted. That is, the UE transmitting the PUCCH toward the same UL reception point as the DL transmission point may transmit the PUCCH using existing PUCCH resources. On the other hand, if UL cell #m (m is a value other than 1), which is a cell different from DL cell 1, is designated as a cell of a reception point, the UE transmits a PUCCH using a PUCCH resource previously reserved for the UL cell #m. It can be configured to. Although PUCCH resources are used here as an example, the embodiment described in this example may be applied to transmission parameters and resources of other channels. For example, a new DMRS sequence different from the existing DMRS sequence may be configured, and which DMRS sequence of the existing DMRS sequence and the new PUSCH DMRS sequence will be used for the PUSCH is included in the DCI format X or separately from the DCI format X. It may be determined by the indication signal transmitted. In particular, the newly configured DMRS sequence may be mainly used for a UL reception point (ie, UL cell) having a different index (eg, different physical cell ID or different virtual cell ID) than the DL transmission point (ie, DL cell). have. Conversely, the newly configured DMRS may be used in a cell of a DL transmission point, and the existing DMRS sequence may be used in a UL cell that is different from the DL cell.

If the DL cell and the UL cell are different, the target UL cell may be designated using CIF. This situation can occur especially when cells of different sizes coexist, such as heterogeneous networks (Hetnet). For example, if DL cell 1 transmits PDSCH1 to the UE, and the UE transmits the PUCCH for the PDSCH1 to UL cell 2 (in this case, the PUSCH is also transmitted to UL cell 2 in general), the eNB Inform the UE that UL cell 2 is the target reception point of the UL transmission. The eNB may indicate the target UL cell to the UE by using the CIF value in the DCI format. It is also possible to add a separate signaling bit for performing this indication function in place of the CIF in the DCI format.

The above-described embodiments can be applied not only to the DCI format for CoMP mode but also to the DCI format of other transmission modes. For example, PUCCH resources may be reserved according to the existing rules for the fallback DCI format, and dynamic PUCCH resources may be configured separately for the DCI format according to the transmission mode according to the present invention. The UE, upon detecting the fallback DCI format, determines the dynamic PUCCH resource according to an existing rule, and when detecting the TM dependent DCI format according to the corresponding transmission mode, the UE may determine the dynamic PUCCH resource among the separately configured PUCCH resources. In other words, embodiments of the present invention can be extended and applied to the general TM dependent DCI format as well as the DCI format for CoMP mode.

11 is a block diagram illustrating components of a transmitter 10 and a receiver 20 for carrying out the present invention.

The transmitter 10 and the receiver 20 are radio frequency (RF) units 13 and 23 capable of transmitting or receiving radio signals carrying information and / or data, signals, messages, and the like, and in a wireless communication system. The device is operatively connected to components such as the memory 12 and 22 storing the communication related information, the RF units 13 and 23 and the memory 12 and 22, and controls the components. And a processor 11, 21 configured to control the memory 12, 22 and / or the RF units 13, 23, respectively, to perform at least one of the embodiments of the invention described above.

The memories 12 and 22 may store a program for processing and controlling the processors 11 and 21, and may temporarily store input / output information. The memories 12 and 22 may be utilized as buffers.

The processors 11 and 21 typically control the overall operation of the various modules in the transmitter or receiver. In particular, the processors 11 and 21 may perform various control functions for carrying out the present invention. The processors 11 and 21 may also be called controllers, microcontrollers, microprocessors, microcomputers, or the like. The processors 11 and 21 may be implemented by hardware or firmware, software, or a combination thereof. When implementing the present invention using hardware, application specific integrated circuits (ASICs) or digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), FPGAs ( field programmable gate arrays) may be provided in the processors 400a and 400b. Meanwhile, when implementing the present invention using firmware or software, the firmware or software may be configured to include a module, a procedure, or a function for performing the functions or operations of the present invention, and configured to perform the present invention. The firmware or software may be provided in the processors 11 and 21 or stored in the memory 12 and 22 to be driven by the processors 11 and 21.

The processor 11 of the transmission apparatus 10 is predetermined from the processor 11 or a scheduler connected to the processor 11 and has a predetermined encoding and modulation on a signal and / or data to be transmitted to the outside. After performing the transmission to the RF unit 13. For example, the processor 11 converts the data sequence to be transmitted into K layers through demultiplexing, channel encoding, scrambling, and modulation. The coded data string is also called a codeword and is equivalent to a transport block, which is a data block provided by the MAC layer. One transport block (TB) is encoded into one codeword, and each codeword is transmitted to a receiving device in the form of one or more layers. The RF unit 13 may include an oscillator for frequency upconversion. The RF unit 13 may include N _t transmit antennas, where N _t is a positive integer greater than or equal to one.

The signal processing of the receiver 20 is the reverse of the signal processing of the transmitter 10. Under the control of the processor 21, the RF unit 23 of the receiving device 20 receives a radio signal transmitted by the transmitting device 10. The RF unit 23 may include N _r receive antennas, and the RF unit 23 frequency down-converts each of the signals received through the receive antennas to restore the baseband signal. . The RF unit 23 may include an oscillator for frequency downconversion. The processor 21 may decode and demodulate a radio signal received through a reception antenna to restore data originally transmitted by the transmission apparatus 10.

The RF units 13, 23 have one or more antennas. The antenna transmits a signal processed by the RF units 13 and 23 to the outside or receives a radio signal from the outside according to an embodiment of the present invention under the control of the processors 11 and 21. , 23). Antennas are also called antenna ports. Each antenna may correspond to one physical antenna or may be configured by a combination of more than one physical antenna elements. The signal transmitted from each antenna can no longer be decomposed by the receiver 20. A reference signal (RS) transmitted corresponding to the corresponding antenna defines an antenna viewed from the perspective of the receiving apparatus 20, and includes a channel or whether the channel is a single radio channel from one physical antenna. Regardless of whether it is a composite channel from a plurality of physical antenna elements, the receiver 20 enables channel estimation for the antenna. That is, the antenna is defined such that a channel carrying a symbol on the antenna can be derived from the channel through which another symbol on the same antenna is delivered. In the case of an RF unit supporting a multi-input multi-output (MIMO) function for transmitting and receiving data using a plurality of antennas, two or more antennas may be connected.

In the embodiments of the present invention, the UE operates as the transmitter 10 in the uplink and the receiver 20 in the downlink. In the embodiments of the present invention, the eNB operates as the receiving device 20 in the uplink, and operates as the transmitting device 10 in the downlink. Hereinafter, the processor, the RF unit and the memory provided in the UE will be referred to as a UE processor, the UE RF unit and the UE memory, respectively, and the processor, the RF unit and the memory provided in the eNB will be referred to as an eNB processor, the eNB RF unit and the eNB memory, respectively.

According to embodiments of the present invention, the eNB processor controls the eNB RF unit to transmit the PDCCH and / or PDSCH, and the UE processor controls the UE RF unit to receive the PDCCH and / or PDSCH. According to embodiments of the present invention, the UE processor controls the eNB RF unit to transmit the PUCCH and the PUSCH, and the eNB processor controls the eNB RF unit to receive the PUCCH and the PUSCH. In the present invention, each receive / transmit point may comprise at least an RF unit. When CoMP is configured, the DL transmission point and the UL reception point may be different, but the points participating in CoMP will be controlled by one eNB processor or by eNB processors that cooperate with each other. When one of the points transmits a DL signal to the UE and one of the points participating in the CoMP receives an UL signal from the UE, the same eNB transmits the DL signal and receives the UL signal. Embodiments of the invention will be described. For example, even when an eNB transmitting a PUCCH resource index offset regarding dynamic PUCCH resources and an eNB receiving a UCI using a PUCCH resource based on the PUCCH resource index offset are different from each other in the following description, the same eNB is seen. Embodiments of the present invention will be described by transmitting downlink signals and uplink signals according to the present invention. However, embodiments of the present invention can be applied even when the eNB transmitting the DL signal and the eNB receiving the UL signal are different.

The eNB processor may control the eNB RF unit to transmit information indicating a transmission mode to the UE. In addition, the eNB processor may configure a plurality of PUCCH resource regions. The eNB processor may control the eNB RF unit to transmit location information (eg, a starting PUCCH resource index) to the UE, which may specify a location of each of the plurality of PUCCH resource regions. For example, the eNB processor may control the eNB RF unit to send one or more PUCCH resource index offset (s) for the transmission mode to the UE in addition to N ⁽¹⁾ _PUCCH which is a cell specific PUCCH resource index offset. have. Each PUCCH resource index offset may correspond to one cell.

The UE RF unit receives the downlink signal from the eNB and passes it to a UE processor. The UE processor attempts to decode the PDCCH in the CSS and / or USS in the subframe to receive the DCI. The UE processor decodes a downlink signal received on a PDCCH in CSS and / or USS in a DCI format (hereinafter, DCI format X) and / or a fallback DCI format according to the transmission mode, thereby transmitting the DCI transmitted to the UE by the eNB. Can be detected / received. If the DCI is successfully decoded by DCI format X, the UE processor may operate in the transmission mode and when the DCI is successfully decoded by fallback DCI format, the UE processor may operate in fallback mode. If the DCI is a DCI for a downlink grant, the UE processor controls the UE RF unit to receive downlink data through a PDSCH according to the downlink grant. The UE processor may control the UE RF unit to generate ACK / NACK information for the downlink data and transmit the ACK / NACK information. When the UE processor successfully decodes the DCI in DCI format X (that is, when detecting the DCI in DCI format X), the UE processor uses the PUCCH resource in the PUCCH resource region configured for DCI format X to transmit the ACK / NACK information. If the UE RF unit is controlled to transmit and the decoding of the DCI is successful in the fallback DCI format (that is, when the DCI of the fallback DCI format is detected), the PUCCH resource in the PUCCH resource region configured for the fallback DCI format is used. The UE RF unit may be controlled to transmit ACK / NAK information. The PUCCH resource region for the fallback DCI format may be an existing dynamic PUCCH resource region, and its starting position may be determined by N ⁽¹⁾ _PUCCH . Which PUCCH resource among the PUCCH resources included in the PUCCH resource region may be determined based on the index n ⁽ _CCE ) of the (first) CCE in the PDCCH carrying the DCI. The PUCCH resource for the ACK / NACK information for the PDSCH in the fallback DCI format may be determined according to Equation 5 and / or Equation 6. The UE processor may determine the ACK / NACK information for the PDSCH according to the DCI format X. PUCCH resources may be determined from among PUCCH resources configured for the DCI format X, that is, for the transmission mode, based on n ⁽ _CCE ).

Meanwhile, when the DCI format is detected, the UE processor may control the UE RF unit and / or the UE memory to perform a predetermined operation. Cell selection parameter (s) such as which reception point the UE RF unit will perform UL transmission, which cell will be targeted to perform UL transmission, which cell ID will be used to perform UL transmission, and so on. Can be specified in advance. In addition, the UE processor may select PUSCH transmission parameter (s) such as which PUSCH DMRS to use, etc., selection of SRS transmission parameter (s) such as which sequence or RB to transmit using SRS, and PUCCH to determine what resource ( Selection of PUCCH transmission parameter (s), such as whether to use CS / OCC, RB, hopping, cell ID), etc. may be specified in advance. The parameter set is preconfigured by the eNB processor, and information about the configured parameter set may be transmitted to the UE by the eNB RF unit. The UE processor may be configured to use the designated parameter set according to the DCI format. The eNB processor may configure a plurality of parameter sets in advance and configure a higher layer signal with information about the configured parameter sets. The eNB processor may control the eNB RF unit to transmit the higher layer signal. The UE RF unit may receive and transmit the layer signal to the UE processor. The UE processor may select one or some of the plurality of parameter sets to use for UL transmission. The UE processor may be configured to use a specific parameter set coupled to the specific DCI if a specific DCI is detected. If the DCI format for the plurality of parameter sets is one, the UE processor may be configured to select one of the plurality of parameter sets using additional information included in the DCI format. The eNB processor may control the eNB RF unit to transmit information on a parameter set that the UE wants to use for actual transmission from the parameter sets reserved by the eNB for a specific DCI format to the UE through a PDCCH. . For example, the eNB processor may use the CIF to indicate one parameter set of a plurality of parameter sets.

Meanwhile, an indication signal separate from the DCI may be used to indicate which of the reserved resources or parameters will be used. For example, the eNB processor may control the eNB RF unit to transmit DCI format X to the UE, and which resource and parameter to use, may control the eNB RF unit to transmit a separate indication signal to the UE. . The UE processor may know that the reserved resources and parameters may be used upon detecting the DCI format X, and may perform UL transmission using any of the previously reserved resources and parameters based on the indication signal. You can see if it should be done.

When the UE RF unit receives the PDSCH in DL cell 1 and transmits the PUCCH for the PDSCH toward UL cell 1 which is the same point as the DL cell 1, the UE processor is configured to transmit a PUCCH resource connected to the CCE of the DL cell 1. The UE RF unit may be controlled to transmit UCI (eg, ACK / NACK information) through the PUCCH. On the other hand, if UL cell #m (m is a value other than 1), which is a cell different from DL cell 1, is designated as a cell of the reception point, the UE processor uses a PUCCH resource previously reserved for the UL cell #m to perform PUCCH. The UE RF unit may be controlled to transmit the UCI through.

Meanwhile, the eNB processor may divide and configure dynamic PUCCH resources into several PUCCH resource regions in advance according to a purpose. For example, one PUCCH resource region may be selected and used among the various PUCCH resource regions according to a DCI format or a transmission mode or higher layer signaling. For example, the collection of certain CCE indexes among the entire CCE indexes may be previously defined as being connected to PUCCH resource region 1 and the collection of remaining CCE indexes to PUCCH resource region 2. The UE processor may decode the DL grant and determine which PUCCH resource region in PUCCH resource region 1 and PUCCH resource region 2 to select a PUCCH resource according to which CCE collection the obtained CCE index belongs to. The UE processor may also implicitly / dynamically determine which individual PUCCH resources in the corresponding PUCCH resource region will be used based on the CCE index. The eNB processor allocates the DL grant of the CoMP UE and the DL grant of the generic UE to the CCEs linked to different PUCCH resource regions, thereby ACK / NACK for the DL grant of the CoMP UE and the ACK / NACK for the DL grant of the generic UE. This can be prevented from using the same PUCCH resource.

The PUCCH resource region may be selected according to the CCE aggregation level. That is, the PUCCH resource region may be determined by linking a specific aggregation level with a specific CCE index. For example, the UE processor selects a PUCCH resource in an existing PUCCH resource region according to an existing PUCCH resource linkage rule for a DCI detected at a high aggregation level (eg, aggregation level 4 or 8), and selects a low aggregation level (eg, For example, for the DCI detected at the aggregation level 1 or 2), the PUCCH resource may be selected in the new PUCCH resource region according to the PUCCH resource linkage rule newly introduced according to the present invention. Alternatively, the UE processor may obtain the PUCCH resource region and the corresponding PUCCH resource index depending on the value of a specific field of the DCI format.

In order to prevent the UE from recognizing that the DCI is transmitted at an aggregation level other than the aggregation level transmitted by the eNB due to the overlap of discovery spaces according to the aggregation level, the eNB processor searches for the PDCCH to be linked to the existing PUCCH resource region. The space and the search space of the PDCCH to be linked to the new PUCCH resource region can be configured differently. Alternatively, the UE processor may be configured to determine the correct aggregation level by attempting to decode all other possible aggregation level (s) even if the UE succeeds in decoding the PDCCH at any aggregation level.

When only DCI format 0 is used for scheduling uplink transmission, the eNB processor may control the eNB RF unit to transmit information on whether the corresponding UE should use an existing PUCCH resource or a new PUCCH resource to the UE. . For example, the eNB processor may place DCI format 0 in search space A (eg, USS) or CCE index A range when the UE needs to perform normal operation, or at a specific aggregation level (eg, By using only aggregation level 1 or 2), the UE is informed that the DCI format 0 is related to normal operation, and when the UE needs to perform a special operation, DCI format 0 is searched for search space B (e.g., CSS) or CCE. Positioning in the index B range or using only a specific aggregation level (eg, aggregation level 4 or 8) may inform the UE that the DCI format 0 is for special operation.

Meanwhile, when DCI format 0 is used as the DCI format for fallback DCI and DCI format 4 is used as the DCI format for TM-dependent DCI, the UE processor uses the PUCCH resource in PUCCH resource region 1 when DCI format 0 is detected. The UE RF unit may be controlled to transmit a signal, and when the DCI format 4 is detected, the UE RF unit may be controlled to transmit the UCI using the PUCCH resource in the PUCCH resource region 2.

Meanwhile, although a plurality of PUCCH resource regions configured according to embodiments of the present invention may be distinguished from each other by PUCCH resource index offsets, these PUCCH resource regions may overlap each other according to how an eNB configures actual PUCCH resource index offsets. It may be configured or completely exclusive. In addition, it is considered that the PDCCH is arranged in the data area instead of the control area of FIG. 3. The PDCCH transmitted / received in the data area is called e-PDCCH. The present invention can also be applied when configuring a PUCCH resource region for an e-PDCCH transmitted / received in a data region separately from a dynamic PUCCH resource region for a PDCCH transmitted / received in a control region. The PUCCH resource region for the e-PDCCH may be UE-specifically configured.

According to the present invention, when the cell for transmitting the downlink signal and the cell for receiving the uplink signal are different, the risk of PUCCH resources colliding can be prevented. Accordingly, PUCCH resources can be efficiently operated.

The detailed description of the preferred embodiments of the invention disclosed as described above is provided to enable those skilled in the art to implement and practice the invention. Although the above has been described with reference to preferred embodiments of the present invention, those skilled in the art will variously modify and change the present invention without departing from the spirit and scope of the invention as set forth in the claims below. I can understand that you can. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Embodiments of the present invention may be used in a base station, relay or user equipment, and other equipment in a wireless communication system.

Claims (12)

1. In transmitting a UL signal to a base station by the user equipment in a wireless communication system,

   Receive downlink control information from the base station through a physical downlink shared channel (PDCCH);

   Transmit ACK / NACK (ACKnowledgment / Negative ACK) information associated with the downlink control information to the base station,

   When the format of the downlink control information is a first format, the ACK / NACK information is transmitted by using a first PUCCH resource in a first PUCCH resource region configured for the first format, When the format of the downlink control information is a second format, the ACK / NACK information is transmitted using a second PUCCH resource in a second PUCCH resource region configured for the second format.

   Uplink signal transmission method.
2. The method of claim 1,

   Receiving first indication information indicating the first PUCCH resource region and second indication information indicating the second PUCCH resource region from the base station;

   Uplink signal transmission method.
3. The method of claim 2,

   The first indication information corresponds to the index of the starting first PUCCH resource in the first PUCCH resource region, and the second indication information corresponds to the index of the starting second PUCCH resource in the second PUCCH resource region.

   Uplink signal transmission method.
4. The method of claim 2,

   Each of the first PUCCH resource and the second PUCCH resource is a resource linked to a control channel element (CCE) in the PDCCH.

   Uplink signal transmission method.
5. The method of claim 2,

   Further comprising receiving information indicating a transmission mode from the base station,

   The first format is a format specific to the transmission mode,

   Uplink signal transmission method.
6. In transmitting a UL signal to a base station by the user equipment in a wireless communication system,

   A radio frequency (RF) unit configured to transmit / receive a signal; And

   A processor configured to control the RF unit,

   The processor controls the RF unit to receive downlink control information from the base station through a physical downlink shared channel (PDCCH), and transmits ACK / NACK (ACKnowledgment / Negative ACK) information associated with the downlink control information to the base station. Control the RF unit to transmit,

   When the format of the downlink control information is a first format, the processor transmits the ACK / NACK information by using a first PUCCH resource in a first PUCCH resource region configured for the first format. Control the RF unit to transmit the ACK / NACK information using a second PUCCH resource in a second PUCCH resource region configured for the second format when the format of the downlink control information is a second format. To control the RF unit,

   User device.
7. The method of claim 6,

   The processor controlling the RF unit to further receive, from the base station, first indication information indicating the first PUCCH resource region and second indication information indicating the second PUCCH resource region,

   User device.
8. The method of claim 7, wherein

   The first indication information corresponds to the index of the starting first PUCCH resource in the first PUCCH resource region, and the second indication information corresponds to the index of the starting second PUCCH resource in the second PUCCH resource region.

   User device.
9. The method of claim 7, wherein

   Each of the first PUCCH resource and the second PUCCH resource is a resource linked to a control channel element (CCE) in the PDCCH.

   User device.
10. The method of claim 7, wherein

    The processor controls the RF unit to further receive information indicating a transmission mode from the base station,

    The first format is a format specific to the transmission mode,

    User device.
11. In the base station receives the uplink signal from the user equipment in a wireless communication system,

    Transmitting downlink control information to the user equipment through a physical downlink shared channel (PDCCH);

    Receive ACK / NACK (ACKnowledgment / Negative ACK) information associated with the downlink control information from the user equipment,

    When the format of the downlink control information is a first format, the ACK / NACK information is received by using a first PUCCH resource in a first PUCCH resource region configured for the first format, When the format of the downlink control information is a second format, receiving the ACK / NACK information using a second PUCCH resource in the second PUCCH resource region configured for the second format,

    Uplink signal receiving method.
12. In the base station receives the uplink signal from the user equipment in a wireless communication system,

    A radio frequency (RF) unit configured to transmit / receive a signal; And

    A processor configured to control the RF unit,

    The processor controls the RF unit to transmit downlink control information to the user equipment through a physical downlink shared channel (PDCCH), and provides ACK / NACK (ACKnowledgment / Negative ACK) information associated with the downlink control information. Control the RF unit to receive from a device,

    If the format of the downlink control information is a first format, the processor receives the ACK / NACK information by using a first PUCCH resource in a first PUCCH resource region configured for the first format. And control the RF unit to receive the ACK / NACK information using a second PUCCH resource in a second PUCCH resource region configured for the second format when the format of the downlink control information is a second format. To control the RF unit,

    Base station.

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