KR20130124079A - Apparatus and method for reporting power headroom in multiple component carrier system - Google Patents

Abstract

The present invention relates to a method and apparatus for performing a surplus power report (PHR) by a terminal in a wireless communication system. The method and apparatus further include receiving a PDCCH command from the base station indicating a random access over a physical downlink control channel (PDCCH); Trigger the PHR based on the PHR triggering requirement; A physical random access channel (PRACH) including a random access preamble that is a response to the PDCCH command is transmitted in parallel with the PHR to the base station, and the PHR triggering requirement transmits the PHR and the PRACH in parallel in the same subframe. In this case, the transmission power of the physical uplink shared channel (PUSCH) through which the PHR is transmitted is not required to be scaled down. According to the present invention, when performing the parallel transmission, the terminal can properly perform the scheduling and power control of the base station by excluding the surplus power information that may be distorted due to the transmission power setting related to the physical random access channel.

Description

Apparatus and method for reporting surplus power of a terminal in a multi-component carrier system {APPARATUS AND METHOD FOR REPORTING POWER HEADROOM IN MULTIPLE COMPONENT CARRIER SYSTEM}

The present invention relates to wireless communications, and more particularly, to an apparatus and method for performing surplus power reporting in a multi-component carrier system.

In a typical wireless communication system, although a bandwidth between an uplink and a downlink is set to be different from each other, only one carrier is mainly considered. In the 3GPP (3rd Generation Partnership Project) LTE (Long Term Evolution), the number of carriers constituting the uplink and the downlink is 1 based on a single carrier, and the bandwidths of the UL and the DL are generally symmetrical to be. In this single carrier system, random access is performed using one carrier. However, with the recent introduction of multiple carrier systems, random access can be implemented through multiple component carriers.

The multi-carrier system (or referred to as a multi-component carrier system) refers to a wireless communication system capable of supporting carrier aggregation. Carrier aggregation is a technique for efficiently using fragmented small bands in order to combine physically non-continuous bands in the frequency domain and to have the same effect as using logically large bands.

The terminal goes through a random access (RA) process in order to access the network (network, or network). The purpose of the terminal performing the random access process to the network is initial access (initial access), handover (handover) , Radio resource request (Scheduling Request), uplink timing alignment (uplink timing alignment).

One of the methods for the base station to efficiently utilize the resources of the terminal is to use the power headroom information of the terminal. Power control technology (or power control technology) is an essential core technology for minimizing interference and reducing battery consumption of a terminal for efficient allocation of resources in wireless communication. When the terminal provides surplus power information to the base station, the base station may estimate how much uplink maximum transmission power that the terminal can afford. Accordingly, the base station may transmit an uplink such as a transmit power control (TPC), a modulation and coding scheme (MCS), a bandwidth, and the like within a range of the estimated uplink maximum transmit power. Scheduling may be provided to the terminal.

When the terminal performs parallel transmission in the process of surplus power reporting, distortion occurs in the process of calculating surplus power, which may cause a problem that the base station cannot properly perform uplink scheduling. .

An object of the present invention is to provide an apparatus and method for performing surplus power reporting in a multi-component carrier system.

Another object of the present invention is to provide an apparatus and method for efficiently performing surplus power reporting at the same time as a random access procedure.

Another technical problem of the present invention is to provide an apparatus and method for transmitting surplus power values that are not distorted due to power scaling.

According to an aspect of the present invention, a method for transmitting a surplus power report (PHR) by a terminal in a wireless communication system includes receiving a PDCCH command indicating a random access from the base station through a physical downlink control channel (PDCCH) ; Triggering the PHR based on the PHR triggering requirement; And parallel transmission of a physical random access channel (PRACH) including a random access preamble in response to the PDCCH command to the base station with the PHR, wherein the PHR triggering requirement is: When the PRACH is to be transmitted in parallel, it is required that the transmission power of the physical uplink shared channel (PUSCH) through which the PHR is transmitted is not attenuated or scaled.

According to another aspect of the present invention, a method of performing a surplus power report by the terminal in a wireless communication system, the method comprising: receiving a PDCCH command indicating a random access from the base station via a physical downlink control channel; Triggering the PHR based on the PHR triggering requirement; In the same subframe, due to the parallel transmission of the PHR and the physical random access channel including the random access preamble that is a response to the PDCCH command, the physical uplink shared channel to which the PHR is transmitted is not substantially transmitted. Blocking transmission of the PHR when the transmission power of the PUSCH through which the PHR is transmitted is attenuated and scaled; And when the transmission of the PHR is not blocked, transmitting the PHR and the PRACH in parallel to the base station.

According to another aspect of the present invention, a terminal for performing a surplus power report in a wireless communication system includes a receiving unit for receiving a PDCCH command from the base station for indicating a random access through a physical downlink control channel; A PHR triggering unit for triggering a PHR based on a PHR triggering requirement; And a transmitter for parallel transmission of a physical random access channel including a random access preamble, which is a response to the PDCCH command, to the base station together with the PHR, wherein the PHR triggering unit is configured to parallel the PHR and the PRACH in the same subframe. When transmitting, PHR triggering is performed with the requirement that the transmit power of the physical uplink shared channel through which the PHR is transmitted is not attenuated or scaled.

According to another aspect of the present invention, a terminal performing surplus power reporting in a wireless communication system includes: a receiving unit receiving a PDCCH command indicating a random access from the base station through a physical downlink control channel; A PHR triggering unit for triggering a PHR based on a PHR triggering requirement; In the same subframe, due to the parallel transmission of the PHR and the physical random access channel including the random access preamble that is a response to the PDCCH command, the physical uplink shared channel to which the PHR is transmitted is not substantially transmitted. Or a PHR blocking unit to block transmission of the PHR when the transmission power of the PUSCH through which the PHR is transmitted is attenuated and scaled; And a transmission unit for parallel transmission of the PHR and the PRACH to the base station when the transmission of the PHR is not blocked.

According to the present invention, a terminal performing parallel transmission can selectively provide surplus power information that can be distorted due to the transmission power setting related to the physical random access channel to the base station, and can appropriately perform scheduling and power control of the base station. have.

1 shows a wireless communication system to which the present invention is applied.
2 shows an example of a protocol structure for supporting multiple carriers to which the present invention is applied.
3 shows an example of a frame structure for multi-carrier operation to which the present invention is applied.
4 shows a connection configuration between a downlink component carrier and an uplink component carrier in a multi-carrier system to which the present invention is applied.
5 is a flowchart illustrating a multi-time alignment value acquisition procedure applied to the present invention.
6 is a diagram illustrating timing of an actual TA value application including propagation delay.
7 is a flowchart illustrating a random access performing procedure to which the present invention is applied.
8 shows an example of an extended PHR MAC CE.
9 is a block diagram illustrating a structure of a random access response message according to an embodiment of the present invention.
10 shows an example of a subheader of a MAC PDU to which the present invention is applied.
11 shows an example of an MPR calculation error applied to the present invention.
12 illustrates an example of a power scaling error applied to the present invention.
13 is a flowchart illustrating surplus power reporting between a terminal and a base station according to the present invention.
14 is a block diagram illustrating a structure of a random access response message according to another example of the present invention.
15 is an example of a MAC subheader applied to the present invention.
16 is an example of a MAC control element to which the present invention is applied.
17 is a flowchart illustrating another example of surplus power report between a terminal and a base station according to the present invention.
18 is a flowchart illustrating an example of an environment of a terminal performing PHR transmission in consideration of power scaling according to the present invention.
19 is a flowchart illustrating an example of an operation of a terminal according to the present invention.
20 is a flowchart illustrating the operation of a base station according to the present invention.
21 is a block diagram illustrating a terminal and a base station according to an embodiment of the present invention.

Hereinafter, some embodiments will be described in detail with reference to exemplary drawings. It should be noted that, in adding reference numerals to the constituent elements of the drawings, the same constituent elements are denoted by the same reference symbols as possible even if they are shown in different drawings. In the following description of the embodiments of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present disclosure rather unclear.

1 shows a wireless communication system to which the present invention is applied.

Referring to FIG. 1, a wireless communication system 10 is widely deployed to provide various communication services such as voice, packet data, and the like. The wireless communication system 10 includes at least one base station 11 (BS). Each base station 11 provides communication services to specific cells (15a, 15b, 15c). The cell may again be divided into multiple regions (referred to as sectors).

A user equipment (UE) 12 may be fixed or mobile and may be a mobile station (MS), a mobile terminal (MT), a user terminal (UT), a subscriber station (SS), a wireless device, (personal digital assistant), a wireless modem, a handheld device, and the like. The base station 11 may be called by other terms such as an evolved-NodeB (eNB), a base transceiver system (BTS), an access point, a femto base station, a home node B, . The cell should be interpreted in a generic sense to indicate a partial area covered by the base station 11 and is meant to cover various coverage areas such as a megacell, a macro cell, a microcell, a picocell, and a femtocell.

Hereinafter, downlink refers to communication from the base station 11 to the terminal 12, and uplink refers to communication from the terminal 12 to the base station 11. In the downlink, the transmitter may be part of the base station 11, and the receiver may be part of the terminal 12. In the uplink, the transmitter may be part of the terminal 12, and the receiver may be part of the base station 11. There are no restrictions on multiple access schemes applied to wireless communication systems. (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), Single Carrier-FDMA , OFDM-CDMA, and the like. A TDD (Time Division Duplex) scheme in which uplink and downlink transmissions are transmitted using different time periods, or an FDD (Frequency Division Duplex) scheme in which they are transmitted using different frequencies can be used.

Carrier aggregation (CA) supports a plurality of carriers, also referred to as spectrum aggregation or bandwidth aggregation. Individual unit carriers bound by carrier aggregation are called component carriers (CCs). Each element carrier is defined as the bandwidth and center frequency. Carrier aggregation is introduced to support increased throughput, prevent cost increases due to the introduction of wideband radio frequency (RF) devices, and ensure compatibility with existing systems. For example, if five elementary carriers are allocated as the granularity of a carrier unit having a bandwidth of 20 MHz, it can support a bandwidth of up to 100 MHz.

Carrier aggregation can be divided into contiguous carrier aggregation between successive element carriers in the frequency domain and non-contiguous carrier aggregation between discontinuous element carriers. The number of carriers aggregated between the downlink and the uplink may be set differently. The case where the number of downlink element carriers is equal to the number of uplink element carriers is referred to as symmetric aggregation and the case where the number of downlink element carriers is different is referred to as asymmetric aggregation.

The size (i.e. bandwidth) of the element carriers may be different. For example, if five element carriers are used for a 70 MHz band configuration, then 5 MHz element carrier (carrier # 0) + 20 MHz element carrier (carrier # 1) + 20 MHz element carrier (carrier # 2) + 20 MHz element carrier (carrier # 3) + 5 MHz element carrier (carrier # 4).

Hereinafter, a multiple carrier system (or a multi-component carrier system) refers to a system supporting carrier aggregation. In a multi-carrier system, adjacent carrier aggregation and / or non-adjacent carrier aggregation may be used, and either symmetric aggregation or asymmetric aggregation may be used.

2 shows an example of a protocol structure for supporting multiple carriers to which the present invention is applied.

Referring to FIG. 2, the common medium access control (MAC) entity 210 manages a physical layer 220 using a plurality of carriers. The MAC management message transmitted on a specific carrier may be applied to other carriers. That is, the MAC management message is a message capable of controlling other carriers including the specific carrier. The physical layer 220 may operate as a time division duplex (TDD) and / or a frequency division duplex (FDD).

There are several physical control channels used in the physical layer 220. The physical downlink control channel (PDCCH) informs the UE of resource allocation of a paging channel (PCH), a downlink shared channel (DL-SCH), and hybrid automatic repeat request (HARQ) information related to the DL-SCH. The PDCCH may carry an uplink grant informing the UE of the resource allocation of the uplink transmission. A DL-SCH is mapped to a physical downlink shared channel (PDSCH). A physical control format indicator channel (PCFICH) informs the UE of the number of OFDM symbols used for PDCCHs and is transmitted every subframe. The physical hybrid ARQ indicator channel (PHICH) is a downlink channel, and carries an HARQ ACK / NACK signal, which is a response of an uplink transmission. A physical uplink control channel (PUCCH) carries uplink control information such as an HARQ ACK / NACK signal for downlink transmission, a scheduling request, and a CQI. A physical uplink shared channel (PUSCH) carries an uplink shared channel (UL-SCH). A physical random access channel (PRACH) carries a random access preamble.

3 shows an example of a frame structure for multi-carrier operation to which the present invention is applied.

Referring to FIG. 3, the frame consists of 10 subframes. The subframe includes a plurality of OFDM symbols. Each carrier may have its own control channel (eg, PDCCH). The multicarriers may or may not be adjacent to each other. The terminal may support one or more carriers according to its capabilities.

The element carrier may be divided into a primary component carrier (PCC) and a secondary component carrier (SCC). The terminal may use only one major carrier or use one or more sub-carrier with carrier. A terminal may be allocated a primary carrier and / or secondary carrier from a base station.

4 shows a linkage between a downlink component carrier and an uplink component carrier in a multi-carrier system to which the present invention is applied.

Referring to FIG. 4, the downlink component carriers D1, D2, and D3 are aggregated in the downlink, and the uplink component carriers U1, U2, and U3 are aggregated in the uplink. Where Di is the index of the downlink component carrier and Ui is the index of the uplink component carrier (i = 1, 2, 3). At least one downlink element carrier is a dominant carrier and the remainder is a subordinate element carrier. Similarly, at least one uplink component carrier is a dominant carrier and the remainder is a subindent carrier. For example, D1, U1 are the dominant carriers, and D2, U2, D3, U3 are the subelement carriers.

In the FDD system, the downlink component carrier and the uplink component carrier are configured to be 1: 1. For example, D1 is connected to U1, D2 is U2, and D3 is U1 1: 1. The UE establishes a connection between the downlink component carriers and the uplink component carriers through the system information transmitted by the logical channel BCCH or the terminal dedicated RRC message transmitted by the DCCH. Each connection setting may be cell specific or UE specific.

4 illustrates only a 1: 1 connection setup between the downlink component carrier and the uplink component carrier, but it is needless to say that a 1: n or n: 1 connection setup can also be established. The index of the element carrier does not match the order of the element carriers or the position of the frequency band of the corresponding element carrier.

The primary serving cell may be a security input and a non-access stratum (NAS) in an RRC connection establishment or re-establishment or re-establishment state, Refers to one serving cell that provides mobility information. Depending on the capabilities of the terminal, at least one cell may be configured to form a set of serving cells together with a main serving cell, said at least one cell being referred to as a secondary serving cell.

Therefore, the set of serving cells set for one UE may consist of only one main serving cell, or may consist of one main serving cell and at least one secondary serving cell.

The downlink component carrier corresponding to the main serving cell is referred to as a downlink principal carrier (DL PCC), and the uplink component carrier corresponding to the main serving cell is referred to as an uplink principal carrier (UL PCC). In the downlink, the element carrier corresponding to the secondary serving cell is referred to as a downlink sub-element carrier (DL SCC), and in the uplink, an elementary carrier corresponding to the secondary serving cell is referred to as an uplink sub-element carrier (UL SCC) do. Only one DL serving carrier may correspond to one serving cell, and DL CC and UL CC may correspond to each other.

Therefore, the communication between the terminal and the base station in the carrier system is performed through the DL CC or the UL CC, which is equivalent to the communication between the terminal and the base station through the serving cell. For example, in the method of performing random access according to the present invention, a UE transmits a preamble using UL CC is equivalent to transmitting a preamble using a main serving cell or a secondary serving cell. In addition, receiving a downlink information using a DL CC by a UE can be regarded as equivalent to receiving downlink information using a main serving cell or a secondary serving cell.

On the other hand, the main serving cell and the secondary serving cell have the following characteristics.

First, the main serving cell is used for transmission of the PUCCH. On the other hand, the secondary serving cell can not transmit the PUCCH, but some of the information in the PUCCH can be transmitted through the PUSCH.

Second, the main serving cell is always activated, while the secondary serving cell is a carrier that is activated / deactivated according to certain conditions. The specific condition may be a case where an activation / deactivation indicator of the base station is received or an inactivation timer in the terminal expires. Activation means that the transmission or reception of traffic data is performed or is in a ready state. Deactivation means that transmission or reception of traffic data is impossible and measurement or transmission / reception of minimum information is possible.

Third, RRC reconnection is triggered when the primary serving cell experiences RLF, but RRC reconnection is not triggered when the secondary serving cell experiences RLF. The radio link failure occurs when downlink performance is maintained below a threshold for a predetermined time or more, or when random access (RA) fails by a threshold or more times.

Fourth, the main serving cell may be changed by a security key change or a handover procedure accompanied by the RACH procedure. However, in the case of a contention resolution (CR) message, only the PDCCH indicating the contention resolution message should be transmitted through the main serving cell, and the contention resolution message may be transmitted through the main serving cell or the secondary serving cell.

Fifth, NAS information is received through the main serving cell.

Sixth, the main serving cell always consists of a pair of DL PCC and UL PCC.

Seventh, a different CC may be set as a primary serving cell for each terminal.

Eighth, procedures such as reconfiguration, adding, and removal of the secondary serving cell may be performed by the radio resource control (RRC) layer. In addition to the new secondary serving cell, RRC signaling may be used to transmit the system information of the dedicated secondary serving cell.

Ninth, the main serving cell is a PDCCH (for example, downlink allocation information allocated to a UE-specific search space) configured to transmit control information only to a specific terminal in an area for transmitting control information. Or uplink grant information) and a PDCCH (for example, system information (for example, system information) allocated to a common search space configured for transmitting control information to all terminals in a cell or a plurality of terminals meeting specific conditions). System information), random access response, or transmit power control (TPC). On the other hand, only the UE-specific search space can be set as the serving cell. That is, since the terminal cannot identify the common search space through the secondary serving cell, the terminal cannot receive control information transmitted only through the common search space and data information indicated by the control information.

Among the secondary serving cells, a secondary serving cell in which a common search space can be defined can be defined, and the secondary serving cell is referred to as a special secondary serving cell (special SCell). The special secondary serving cell is always configured as a scheduling cell during cross carrier scheduling. Also, a PUCCH set in the main serving cell may be defined for the special-purpose serving cell.

The PUCCH for the special secondary serving cell may be fixedly set in the special secondary serving cell configuration or the base station may be allocated (configured) or released by RRC signaling (RRC reconfiguration message) upon reconfiguration for that secondary serving cell have.

The PUCCH for the special secondary serving cell includes ACK / NACK information or channel quality information (CQI) of secondary serving cells existing in a corresponding secondary timing advancement group (sTAG), as mentioned above. It may be configured through the RRC signaling by the base station.

In addition, the base station may configure a special secondary serving cell of one of a plurality of secondary serving cells in the sTAG, or may not configure a special secondary serving cell. The reason for not configuring the special secondary serving cell is that it is determined that the common search space and the PUCCH need not be set. For example, if the contention-based random access procedure does not need to proceed in any serving cell, or if it is determined that the capacity of the current serving cell's PUCCH is sufficient and the PUCCH for the additional serving cell is not needed .

The technical idea of the present invention regarding the characteristics of the main serving cell and the secondary serving cell is not necessarily limited to the above description, but is merely an example and may include more examples.

In a wireless communication environment, a propagation delay may be experienced while a radio wave propagates in a transmitter and is transmitted in a receiver. Therefore, even if the transmitter and the receiver both know the time at which the radio wave is propagated correctly, the arrival time of the signal to the receiver is influenced by the transmission / reception period distance and the surrounding propagation environment. If the receiver does not know exactly when the signal transmitted by the transmitter is received, it will receive the distorted signal even if it fails to receive or receive the signal.

Therefore, in the wireless communication system, synchronization between the base station and the terminal must be predetermined in order to receive the information signal regardless of the downlink / uplink. Types of synchronization include frame synchronization, information symbol synchronization, and sampling period synchronization. Here, the sampling period synchronization is the most basic synchronization to be obtained in order to distinguish the physical signals.

The downlink synchronization acquisition is performed in the UE based on the signal of the base station. The base station transmits a mutually agreed specific signal for facilitating downlink synchronization acquisition at the terminal. The terminal must be able to accurately identify the time at which a particular signal sent from the base station is transmitted. In case of downlink, since one base station simultaneously transmits the same synchronization signal to a plurality of terminals, each of the terminals can acquire synchronization independently of each other.

In case of uplink, the base station receives signals transmitted from a plurality of terminals. When the distance between each terminal and the base station is different, signals received by each base station have different transmission delay times. When uplink information is transmitted based on downlink synchronization acquired by each terminal, And is received at the corresponding base station. In this case, the base station can not acquire synchronization based on any one of the terminals. Therefore, uplink synchronization acquisition requires a procedure different from downlink.

Now, timing alignment (TA, or timing advance (TA)) and multiple time alignment (multiple TA, or multiple time advance) for uplink synchronization acquisition of the UE will be described.

A random access procedure is performed to obtain uplink synchronization of the UE, and the UE performs uplink synchronization based on a timing alignment value (TA), which is transmitted from the base station, during the random access procedure. Acquire it. In order to advance the uplink time, the time alignment value may be referred to as a timing advance value.

When the terminal acquires uplink synchronization, the terminal starts a timing alignment timer (TAT). While the time alignment timer is in operation, the terminal and the base station are in synchronization with each other. If the time alignment timer expires or does not operate, the terminal and the base station determine that they are not synchronized with each other, the terminal does not perform uplink transmissions other than the transmission of the random access preamble.

Meanwhile, in a multi-carrier system, one terminal communicates with a base station via a plurality of element carriers or a plurality of serving cells. If all the signals of the plurality of serving cells set in the UE have the same time delay, the UE can acquire uplink synchronization for all the serving cells with only one time alignment value. On the other hand, if the signals of the plurality of serving cells have different time delays, a different time alignment value is required for each serving cell. That is, multiple timing alignment values are required. If the UE performs random access to each serving cell in order to obtain multi-time alignment values, overhead occurs in the limited uplink resources, and the complexity of the random access may increase. A timing alignment group (TAG) is defined to reduce this overhead and complexity.

The time alignment group is a group including serving cell (s) using the same time alignment value and the same timing reference among the serving cells configured with the UL CC. Each time alignment group includes only a serving cell configured with a UL CC and includes at least one serving cell configured with the UL CC. The information on the serving cells mapped to each time alignment group is referred to as time alignment group configuration information (hereinafter referred to as 'TAG configuration information').

For example, when the first serving cell and the second serving cell belong to the same time alignment group, the same time alignment value TA1 is applied to the first serving cell and the second serving cell. On the other hand, when the first serving cell and the second serving cell belong to different time alignment groups, different time alignment values TA1 and TA2 are applied to the first serving cell and the second serving cell, respectively.

The time alignment group may include a main serving cell, may include at least one secondary serving cell, and may include a primary serving cell and at least one secondary serving cell.

In the time alignment group, initial group setup and group realignment are determined by the serving base station configuring the corresponding serving cell, and the TAG configuration information is transmitted to the terminal through RRC signaling.

The main serving cell does not change the TAG.

The terminal supports at least two TAGs when a multi-time alignment value is required. For example, a TAG is classified into a pTAG (primary TAG) including a main serving cell and a TAG (secondary TAG) not including a main serving cell. Here, only one pTAG always exists, whereas one or more sTAG may be present when a multi-time alignment value is required. At this time, the number of TAG may be set to a maximum of two or a maximum of four. It may also be set to always have a value of TAG ID = 0 for the pTAG.

The serving base station and the terminal may proceed all or part of the following operations to obtain and maintain time alignment values for each time alignment group.

1. TA value acquisition and maintenance of pTAG always proceed through the main serving cell. In addition, a timing reference as a reference for downlink synchronization for calculating a TA value of pTAG is always a DL CC in a main serving cell.

2. In order for the UE to obtain an initial uplink time alignment value for the sTAG, a random access procedure initialized by the base station is used.

3. A timing reference to sTAG may be used for one of the active secondary serving cells. However, it is assumed that there is no change in unnecessary timing reference.

4. Each TAG has one timing reference and one time alignment timer (TAT). Each TAT may be configured with a different timer expiration value and may operate independently of each other. The TAT starts or restarts immediately after acquiring the time alignment value from the serving base station to determine whether the time alignment value obtained and applied by each time alignment group is valid.

5. If the TTAG for pTAG is not in progress, the TAT for all sTAGs is not in progress, i.e. the TAT for all TAGs including pTAG expires, and the TAT for all sTAGs starts when no TAT for pTAG is in progress. I never do that. When the TAT of the pTAT expires, the terminal flushes HARQ buffers of all serving cells. In addition, the terminal clears the resource allocation configuration for all downlink and uplink (clear). For example, when periodic resource allocation is configured without control information transmitted for resource allocation for downlink or uplink, such as PDCCH, such as semi-persistent scheduling (SPS), the SPS configuration Initialize In addition, the configuration of the PUCCH and type 0 SRS (cyclic sounding reference signal) of all serving cells is released.

6. If only the TAT of the sTAG has expired, the terminal stops SRS transmission through the UL CC of the secondary serving cells in the sTAG, the terminal releases the type 0 SRS (cyclic SRS) configuration and type 1 SRS (aperiodic SRS) The configuration is maintained, the terminal maintains the configuration information for the CSI report, the terminal (flush) the HARQ buffers for the uplink of the secondary serving cells in the sTAG.

7. If the TAT for the sTAG is in progress, even if all secondary serving cells in the sTAG are deactivated, the terminal proceeds without stopping the TAT of the corresponding sTAG. This guarantees the validity of the TA value of the corresponding sTAG through the TAT even when all secondary serving cells in the sTAG are inactive and no SRS transmission or uplink transmission for tracking uplink synchronization is maintained for a certain time. It means you can.

8. If the last secondary serving cell in the sTAG is removed, that is, no secondary serving cell in the sTAG is configured, the TAT in that sTAG is stopped.

9. The random access procedure for the secondary serving cell may be performed by the base station transmitting only a PDCCH order for the activated secondary serving cell. That is, only the contention-free random access procedure proceeds. The random access preamble information included in the PDCCH command is indicated by information other than '000000'.

10. The PDCCH for random access response transmission may be transmitted through a serving cell other than the secondary serving cell in which the random access preamble is transmitted.

11. The procedure when the number of retransmissions of the random access preamble of the secondary serving cell reaches the maximum allowed number of retransmissions is as follows.

A) The MAC layer stops the random access procedure.

B) The MAC layer does not inform the RRC layer that the random access has failed and therefore does not cause triggering of the RLF.

C) The terminal does not notify the base station that the random access of the serving cell has failed.

12. A pathloss (pathloss) reference of a pTAG may be a primary serving cell or a secondary serving cell in a pTAG, and may be set differently through RRC signaling by a base station for each serving cell in the pTAG.

13. Path loss references of UL CCs of each of the serving cells in the sTAG are DL CCs configured with a System Information Block 2, respectively.

5 is a flowchart illustrating a multi-time alignment value acquisition procedure applied to the present invention.

Referring to FIG. 5, the UE performs an RRC connection establishment procedure (hereinafter referred to as an RRC connection establishment procedure or RRC connection establishment procedure) with a base station through a selected cell (S500). The selected cell becomes the main serving cell.

The base station performs an RRC connection configuration procedure or an RRC connection reconfiguration procedure for additionally configuring at least one secondary serving cell in the terminal (S505). For example, a secondary serving cell may be added when it is necessary to allocate to a terminal of more radio resources by a request of a terminal, a request of a network, or a self determination of a base station.

The base station configures (or defines) a time alignment group for the serving cell added to the terminal (S510). In a carrier aggregation situation, TAG setting between serving cells may be performed cell-specifically. For example, when a serving cell of a specific frequency band is always serviced through a frequency selective repeater (FSR) or a remote radio head (RRH), serving of the specific frequency band for all terminals in the service area of the base station. Serving cells served directly from the cell and the base station are configured to belong to different TAGs even though they may be set to the same TA value.

If the base station determines that the same time alignment value as the main serving cell can be applied to the added secondary serving cell, the added secondary serving cell is set to the same TAG as the primary serving cell. In this case, TAG configuration information such as the following step S515 may not be transmitted. If the terminal receives the activation indicator and uplink scheduling information for the added secondary serving cell without receiving the TAG configuration information, the terminal may determine that the added secondary serving cell is set to the same TAG as the main serving cell. have.

If the base station determines that the same time alignment value as the main serving cell cannot be applied to the added secondary serving cell, the base station configures an sTAG including the added secondary serving cell. Each TAG is given a TAG ID for identifying the TAG. However, the base station may selectively assign a TAG ID for the sTAG.

As an example, when the base station determines that the sTAG including the added secondary serving cell is a different TAG from previously configured TAGs, the base station acquires a TAG ID for the sTAG before acquiring uplink synchronization through a random access procedure. Can be given.

As another example, when the base station determines that the added secondary serving cell may be included in an existing TAG or cannot determine which TAG it is included in, the base station performs the random access procedure before acquiring uplink synchronization. The TAG ID for the sTAG may not be assigned. In this case, the base station transmits the TAG configuration information to the terminal as necessary after the terminal acquires the uplink synchronization, the terminal may obtain the TAG ID of the sTAG.

Following step S510, the base station transmits the TAG configuration information to the terminal (S515).

For example, the TAG configuration information may be in a format including TAG ID information for each secondary serving cell. In more detail, the uplink configuration information of each secondary serving cell may include TAG ID information.

As another example, the TAG configuration information may be a format for mapping a serving cell index (ServCellIndex) allocated to each serving cell or a secondary serving cell index (ScellIndex) allocated only to secondary serving cells. For example, pTAG = {ServCellIndex = 1, 2}, sTAG1 = {ServCellIndex = 3, 4}.

As another example, the main serving cell is always TAG ID = 0 and there is no configuration information. In addition, if there is no TAG ID information among the secondary serving cells, the secondary serving cells may mean that the serving cell in the pTAG.

The TAG configuration information may further include timing reference cell information in each TAG. If the TAG configuration information does not include timing reference cell information, the terminal may recognize the timing reference cell in each TAG by itself. For example, the timing reference cell may be recognized through the timing reference cell setting method described above. Alternatively, when the base station configures the secondary serving cell, the serving cell including parameters for the random access procedure may be selected as the timing reference cell. If there are a plurality of serving cells that meet the condition that may be a timing reference cell or the timing reference cell is deactivated, the secondary serving cell having the lowest secondary serving cell index may be set as the timing reference cell.

After the step S515, when the base station intends to schedule a specific secondary serving cell, the base station transmits an activation indicator for activating the specific secondary serving cell to the terminal (S520).

A random access procedure indicated by the base station is performed (S525). When the UE does not secure uplink synchronization in a specific sTAG, the UE may obtain a time alignment value to be adjusted for the specific sTAG.

In this case, the random access procedure for the activated secondary serving cell in the sTAG may be started by a PDCCH order (PDCCH order) transmitted by the base station. A secondary serving cell capable of receiving a PDCCH command may be limited to a secondary serving cell including a timing reference specified in the sTAG, or may be any secondary serving cell configured for RACH.

In addition, the base station controls so that the terminal does not simultaneously perform two or more random access procedures. Simultaneous progress of the random access procedure includes a case where two or more random access procedures are synchronized and progress simultaneously, and a case where the random access procedure is concurrently progressed for some time when the random access procedure proceeds. For example, when the UE proceeds with the random access procedure through the primary serving cell, the UE starts the random access procedure through the secondary serving cell while waiting for the random access response message (receives the PDCCH order).

In addition, the base station secures enough information to map a specific secondary serving cell to a specific TAG through information obtained in the existing network or assistant information (eg, location information, RSRP, RSRQ, etc.) received from the terminal. If not, the secondary serving cell required for time alignment grouping is set to another sTAG and the uplink time alignment value is obtained through a random access procedure.

6 is a diagram illustrating timing of actual TA value application including propagation delay to which the present invention is applied.

Referring to FIG. 6, a timing advance command (TAC) for uplink synchronization of a terminal and a base station corresponds to all time alignment values transmitted through a random access response or a TAC MAC control element (CE). will be.

After the time forward command is transmitted in the downlink reception of the terminal, the TAC is applied in the uplink transmission of the terminal after "5ms-round trip time (RTT) (for example, at least 4.33ms)."

The UE may start or restart the TAT from a subframe receiving the random access response or start or restart the TAT from an uplink subframe to which a TA value is applied.

Meanwhile, the random access procedure of step S525 may be performed as in the following procedure of FIG. 7.

7 is a flowchart illustrating a random access procedure to which the present invention is applied. This is an example of a non-contention based random access procedure.

Referring to FIG. 7, the base station transmits a PDCCH order (PDCCH order) for instructing the start of a random access procedure for the secondary serving cell configured in the terminal (S700). Random access preamble assignment (RA preamble assignment) may be performed. In the case of a non-contention based random access procedure, the base station selects one of the reserved random access preambles among the available total random access preambles, and the index of the selected random access preamble and the available time / frequency Random access preamble allocation information including resource information is transmitted to the terminal through a PDCCH command. This is because, for the non-contention based random access process, the UE needs to be allocated a dedicated random access preamble with no possibility of collision from the base station.

For example, when the random access procedure is performed during the handover procedure, the terminal may obtain a dedicated random access preamble generated by the target base station from the handover command message through the source base station. For another example, when the random access procedure is performed by a PDCCH order (PDCCH order) of the base station, the UE may obtain a dedicated random access preamble through PDCCH, that is, physical layer signaling. In this case, the physical layer signaling may be downlink control information (DCI) format 1A and may include fields shown in Table 1 below.

Referring to Table 1, the preamble index is an index indicating a preamble selected from among dedicated random access preambles reserved for the contention-free random access procedure, and the PRACH mask index is available time / frequency resource information. The available time / frequency resource information is indicated again according to a frequency division duplex (FDD) system and a time division duplex (TDD) system, as shown in Table 2 below.

Table 2 below shows a PRACH mask index.

The terminal transmits the random access preamble to the base station (S705). Random access preamble transmission on the secondary serving cell is possible only when indicated by the base station.

When the base station successfully receives the random access preamble, the base station may determine which terminal transmits the random access preamble through which serving cell based on the received random access preamble and time / frequency resources.

Meanwhile, in the random access procedure, the base station sets the preamble transmit power based on the received power expected when the base station receives the preamble. Specifically, it may be set as the following equation.

Here, preambleInitialReceivedTargetPower is a value commonly set by the base station to the terminal in the base station and is a reference value for the transmission power set during the initial preamble transmission. In addition, DELTA_PREAMBLE may be preset to 0 or a specific offset value according to the preamble format. In addition, the powerRampingStep value is a transmission power value that is additionally increased with each preamble retransmission. In addition, the UE instructs the UE to transmit the preamble using a selected PRACH, a corresponding random access-radio network temporary identifier (RA-RNTI), a preamble index, and a PREAMBLE_RECEIVED_TARGET_POWER value in the physical layer.

Table 3 below shows the format of the random access preamble.

Referring to Table 3, T _CP is a parameter representing a section of a cyclic prefix (CP) of a PRACH symbol, T _SEQ is a parameter representing a sequence section, and T _S represents a sampling time. According to each format, the number of subframes occupied by the PRACH may be variably defined. For example, in the preamble format 0, the sum of the CP and the sequence is smaller than the subframe, and the maximum cell size (two times the radius) that can consider propagation delay is the smallest. In contrast, in the preamble formats 1, 2, and 3, the sum of the CP and the sequence is one or more subframes. In the preamble format 1 or the format 2, two occupied subframes of the PRACH, and in the preamble format 3, three occupied subframes.

Transmission of the random access preamble triggered by the MAC layer is restricted to specific time / frequency resources. These time / frequency resources are listed in ascending order of subframe numbers in the radio frame and physical resource blocks in the frequency domain, and index 0 corresponds to the smallest numbered physical resource block and subframe of the radio frame. PRACH resources in a radio frame are indicated by a PRACH resource index, which is shown in the following table.

Table 4 shows frame structure type1 random access settings for preamble formats 0 to 3.

For frame structure type 1 of preamble formats 0 to 3, there is a maximum of one random access resource per subframe. Table 4 shows subframes that allow random access preamble transmission in the configuration given in the preamble formats and frame structure type 1 according to Table 3 above. The parameter prach-ConfigurationIndex is given by the upper layer. The start of the random access preamble is aligned with the start of an uplink subframe of the terminal with N _TA == 0. For the PRACH configuration indexes 0, 1, 2, 15, 16, 17, 18, 31, 32, 33, 34, 47, 48, 49, 50, and 63, the UE is a radio frame i of the current cell for handover purposes. Assume that the absolute value of the relative time difference between and the target cell is 153600-T _s . The first physical resource block (n ^RA _PRB ) assigned to the PRACH opportunity considered in preamble formats 0, 1, 2 and 3 is defined as n ^RA _PRBoffset , where the parameter prach-FrequencyOffset (n ^RA _PRBoffset ) is higher Represented by a physical resource block number set by the layer, n ^RA _PRBoffset is set to be greater than or equal to 0 and less than or equal to N ^UL _RB- 6.

Subsequently to step S705, the base station transmits the PDSCH, to which the PDCCH of the terminal and the random access response message are mapped, to the terminal (S710). The random access preamble of step S705 is semi-synchronized with the transmission and may be transmitted within a flexible window of two or more Transmission Time Interval (TTI) sizes.

At this time, HARQ (Hybrid Automatic Repeat reQuest) is not transmitted.

Also, as an example, the PDCCH may be scrambled with the RA-RNTI and transmitted.

In the above example, the PDCCH for the random access response of the primary serving cell and the secondary serving cell is scrambled to RA-RNTI and transmitted, and in the PDSCH indicated by the PDCCH, the corresponding UE transmits to the serving cell to which the random access preamble is transmitted. The random access response may be included and transmitted.

In addition, TA information and an initial uplink grant for handover may be transmitted. Alternatively, TA information for downlink data arrival may be transmitted. Alternatively, a random access preamble identifier (RA preamble identifier) for identifying one or more terminals may be transmitted.

The random access response message of the MAC layer may be mapped to the PDSCH alone, or may be multiplexed into a single RAR MAC PDU with random access responses of other terminals and mapped to the PDSCH.

The PDSCH to which the random access response message is mapped is indicated by the PDCCH. The common search space is allocated a PDCCH scrambled by the RA-RNTI. However, since the common search space is not defined in the secondary serving cell and only the UE-specific search space is defined, the terminal receives the PDCCH scrambled by the RA-RNTI and the random access response message indicated by the PDCCH on the secondary serving cell. Can not. Therefore, the PDCCH and PDSCH including the random access response message can always be transmitted only on the primary serving cell. The resource used for transmission of the PDSCH to which the random access response message is mapped is indicated by the resource block allocation field in the DCI.

The UE knows the random access preamble information transmitted from the base station and the serving cell transmitting the random access preamble. In addition, the UE cannot simultaneously perform two or more random access procedures. Accordingly, when the random access preamble information is confirmed in the random access response message of the MAC layer, the terminal may know whether the corresponding random access response information is that of the terminal and information about which serving cell. In order to guarantee the operation of such a terminal, the network including the base station should prevent duplication of allocation between each terminal and the serving cell when the preamble is allocated to each of the serving cells of each terminal.

Now, the power headroom (PH) will be described.

The surplus power means extra power that can be additionally used in addition to the power currently used by the UE for uplink transmission. For example, assume that the maximum transmission power, which is the uplink transmission power of the allowable range of the terminal, is 10W, and assume that the current terminal uses 9W of power in a frequency band of 10Mhz. At this time, since the terminal can additionally use 1W, the surplus power is 1W.

Here, if the base station allocates a frequency band of 20Mhz to the terminal, power of 18W (= 9W * 2) is required. However, since the maximum power of the terminal is 10W, if 20Mhz is allocated to the terminal, the terminal may not use all of the frequency band, or the base station may not properly receive the signal of the terminal because of insufficient power. In order to solve this problem, the terminal reports that the surplus power is 1W to the base station, so that the base station can schedule within the surplus power range. Such a report is called a Power Headroom Report (PHR).

Through the surplus power reporting procedure, 1) information on the difference between the maximum transmit power of the terminal and the estimated UL-SCH (PUSCH) transmit power for each activated serving cell, and 2) the scheduled serving cell. Information on the difference between the maximum transmission power of the terminal and the predicted PUCCH transmission power, or 3) information on the difference between the maximum transmission power scheduled in the main serving cell and the predicted UL-SCH and PUCCH transmission power may be transmitted to the serving base station. have.

The terminal's surplus power report can be defined as two types (Type 1, Type 2). Surplus power of any terminal may be defined for subframe i for serving cell c.

1.Type 1 of surplus power reporting (Type 1 surplus power)

Type 1 surplus power may be 1) when a UE transmits only a PUSCH without a PUCCH, 2) simultaneously transmits a PUCCH and a PUSCH, and 3) a PUSCH is not transmitted.

First, if a UE transmits a PUSCH without a PUCCH for a subframe i for a serving cell c, the residual power for the Type 1 report is given by the following equation.

Where P _{CMAX , c} (i) is the maximum terminal transmit power configured for the serving cell c

To the decibel value [dB].

Here, P _CMAX (i) is determined by a P _EMAX value set based on P-max, which is a value that the base station transmits to the UE through RRC signaling, and a transmission power class determined by the hardware level of each UE P _PowerClass value based on the maximum transmission power value set based on a small value of the power of the terminal. The offset values may include a maximum power reduction (MPR), an additional maximum power reduction (A-MPR), a power management maximum power reduction (P-MPR) And an offset value? T _C applied according to whether the band of the filter in the transmission part of the terminal is high or not can be applied.

Unlike P _CMAX (i) _, P _{CMAX , c} (i) is a value limited to the serving cell c. Accordingly, the P-max value is also a value (P _{EMAX , c} ) configured for the serving cell c, and the offset values are also calculated to be a value configured only for the serving cell c. That is, MPR _c , A-MPR _c , P-MPR _c , and ΔT _{C, c} . However, the P _PowerClass value is calculated by using the same value as the value used in the terminal unit calculation.

Also, M _{PUSCH , c} (i) is a value expressed by the number of RBs in the bandwidth of the resource to which the PUSCH is allocated in the subframe i for the serving cell c.

In addition, P _{O _ PUSCH , c} (j) is the sum of P _{O _ NOMINAL _ PUSCH , c} (j) and P _{O _ UE _ PUSCH , c} (j) for the serving cell c, 0 or 1. J is 0 for semi-persistent grant PUSCH transmission (or retransmission) whereas j is 1 for dynamic scheduled grant PUSCH transmission (or retransmission), while random access response grant PUSCH transmission (Or retransmission), j is 2. In the case where the random access response grant PUSCH transmission (or _{retransmission) P O _ UE _ PUSCH,} c (2) = 0 , and, P _{O _ NOMINAL _ PUSCH, c} (2) is P _{O _ PRE} and Δ _{PREAMBLE _ Msg3} the sum of a, in which the parameter P _{O_PRE} (preambleInitialReceivedTargetPower) and Δ _{PREAMBLE _ Msg3} is signaled from higher layers.

If j is 0 or 1, one of the values α _c ∈ {0, 0, 4, 0.5, 0.6, 0.7, 0.8, 0.9, 1} may be selected by the 3-bit parameter provided in the upper layer. When j is 2, α _c (j) = 1 at all times.

PL _c is a dB value of the downlink path loss (PL, or path loss) estimate for the serving cell c calculated by the UE, and can be obtained from "referenceSignalPower-higher layer filtered RSRP". Here, referenceSignalPower is a value provided in the upper layer, and is a unit of dBm of the EPRE (Energy Per Resource Element) value of the DL reference signal. Reference Signal Received Power (RSRP) is the received power value of the reference signal for the reference serving cell. The decision of the serving cell selected as the reference serving cell and the referenceSignalPower and the higher layer filtered RSRP used for the calculation of the PL _c is made by the upper layer parameter pathlossReferenceLinking. Here, the reference serving cell formed by the pathlossReferenceLinking may be the DL serving cell of the serving cell or the serving serving cell connected to the UL CC and the SIB2 connection.

Further,? _{TF , c} (i) is a parameter for reflecting an influence by a modulation coding scheme (MCS)

to be. Here, K _s is a parameter provided as deltaMCS-Enabled in the upper layer for each serving cell c and is 1.25 or 0. In particular, in the case of transmission mode 2, which is a mode for transmit diversity K _s is always zero. Also, when only control information is transmitted through the PUSCH without UL-SCH data, BPRE = O _CQI / N _RE , and in other cases

Inde, C is the number of code blocks, K _r is the size of the code block, O _CQI is CQI / PMI bit number including the number of CRC bits, N _RE is the number of the determined resource element (Resource Element) (i.e.,

)to be. Also, if only the control information is transmitted without the UL-SCH data through the PUSCH

. Otherwise, β ^PUSCH _offset is always set to 1.

Also, δ _{PUSCH , c} is a correction value, which is a TPC command (TPC command) existing in DCI format 0 or DCI format 4 for the serving cell c, or DCI format 3 / 3A. ≪ / RTI > In the DCI format 3 / 3A, the CRC parity bits are scrambled with the TPC-PUSCH-RNTI so that only the UEs to which the RNTI value is assigned can be checked. Herein, when the RNTI value is configured by a plurality of serving cells, a different RNTI value may be allocated to each serving cell in order to distinguish each serving cell. At this time, the PUSCH power control adjustment state for the current serving cell c is given by f _c (i), or when the accumulation is activated by the upper layer with respect to the serving cell c or when the TPC command 隆_{PUSCH ,} If the DCI format 0 scrambled by a Temporary) -C-RNTI is included in the PDCCH is _{"f c (i) = f} c (i-1) + δ PUSCH, c (iK PUSCH)". Where δ _{PUSCH , c} (iK _PUSCH ) is the TPC command in the DCI format 0/4 or 3 / 3A in the PDCCH that was transmitted in the (iK _PUSCH ) th subframe and f _c (0) is the first value after the cumulative reset . In addition, the K _PUSCH value is 4 in the case of FDD. If there is a PDCCH scheduling PUSCH transmission in subframe 2 or 7 in the TDD UL / DL setting 0, if the LSB (Least Significant Bit) value of the UL index is set to 1 in the DCI format 0/4 in the PDCCH K _PUSCH is 7.

Second, if the UE simultaneously transmits PUCCH and PUSCH for subframe i for serving cell c, the type 1 redundant power is expressed by the following equation.

here,

Is a value calculated on the assumption that there is only PUSCH transmission in subframe i. In this case, the physical layer is replaced by P _{CMAX , c} (i)

To the upper layer.

Third, if the PUSCH is not transmitted for the subframe i for the serving cell c, the type 1 residue power is expressed by the following equation.

here,

The MPR is 0dB, A-MPR is 0dB, P-MPR is 0dB, and _C ΔT is calculated assuming that the 0dB.

2. Type 2 of Surplus Power Reporting (Type 2 Surplus Power)

The Type 2 redundant power is used when the UE transmits PUCCH and PUSCH for subframe i for the main serving cell at the same time, transmits PUSCH without PUCCH, transmits PUCCH without PUSCH, and does not transmit PUCCH or PUSCH There is a case.

First, if the UE simultaneously transmits PUCCH and PUSCH for subframe i for the main serving cell, the Type 2 redundant power is calculated according to the following equation.

Here, Δ _{F_ PUCCH} (F) is defined in an upper layer (RRC), each Δ _{F_ PUCCH} (F) value corresponds to the associated PUCCH format (F) and the PUCCH formats 1a. Here, each PUCCH format (F) is shown in the following table.

If the terminal is configured for two antenna ports by the upper layer, the value of DELTA _TxD (F ') for each PUCCH format F' is provided in the upper layer. If not, then Δ _TxD (F ') = 0.

Also, h (n _CQI , n _HARQ , n _SR ) has different values for each PUCCH format. Where n _CQI represents the number of bits of CQI (channel quality information) information. Also, if SR (scheduling request) is configured in sub-frame i and no SR configuration exists in any transport block related to the UL-SCH of the UE, n _SR = 1 and n _SR = 0 otherwise. If the UE is set in one serving cell, n _HARQ is the number of HARQ-ACK bits transmitted in subframe i. H (n _CQI , n _HARQ , n _SR ) = 0 for PUCCH format 1 / 1a / 1b. H (n _CQI , n _HARQ , n _SR ) = (n _HARQ -1) / 2 if the UE is set in one or more serving cells for PUCCH format 1b of channel selection, _CQI , n _HARQ , n _SR ) = 0. (N _CQI , n _HARQ , n _SR ) = ₁₀ log ₁₀ (n _CQI / 4) if the n _CQI is equal to or greater than 4 for the PUCCH format 2 / 2a / 2b and the normal cyclic prefix, H (n _CQI , n _HARQ , n _SR ) = 0. PUCCH format 2, and the extended cyclic prefix _{(extended cyclic prefix) "n CQI} + n HARQ" is greater than or equal to 4 with respect to _{h (n CQI, n HARQ,} n SR) = 10log 10 ((n CQI + n HARQ) / 4), and otherwise h (n _CQI , n _HARQ , n _SR ) = 0. For PUCCH Format 3, if the UE is configured to transmit a PUCCH at a 2-antenna port by an upper layer or if the UE is set to transmit 11-bit HARQ-ACK / SR, then h (n _CQI , n _HARQ , n _SR ) = (n _HARQ + n _SR -1) / 3, and otherwise h (n _CQI , n _HARQ , n _SR ) = (n _HARQ + n _SR -1) / 2. P _{O _ PUCCH} is a parameter composed of the sum of P and P parameters _{O_NOMINAL_PUCCH O _ _ UE PUCCH} parameters provided by the higher layers.

Second, if a mobile station transmits a PUSCH without a PUCCH for a subframe i for a main serving cell, the type 2 redundant power is calculated by the following equation.

Third, if the UE transmits a PUCCH without a PUSCH to a subframe i for a main serving cell, the type 2 redundant power is calculated by the following equation.

Fourth, if the UE does not transmit PUCCH or PUSCH for subframe i for the main serving cell, the Type 2 redundant power is calculated as follows.

here,

The MPR is 0dB, A-MPR is 0dB, P-MPR is 0dB, and _C ΔT is calculated assuming that the 0dB.

The residual power value is determined in units of 1 dB and should be determined by rounding to the nearest one of the values in the range of 40 dB to -23 dB. The determined excess power value is transferred from the physical layer to the upper layer.

On the other hand, the reported residual power is an estimated value in one subframe.

If an extended PHR (Extended PHR, hereinafter referred to as extended PHR) is not configured, only Type 1 redundant power values for the main serving cell are reported. On the other hand, if extended surplus power reporting is configured, a Type 1 redundant power value and a Type 2 redundant power value are reported for each active serving cell configured for uplink. Extended surplus power reporting is described in detail below.

The surplus power reporting delay refers to a difference between the start time of the surplus power reference interval and the time at which the UE starts transmitting surplus power values through the air interface. The surplus power reporting delay should be 0ms and the surplus power reporting delay may be applied to all configured triggering techniques for surplus power reporting.

The mapping of reported surplus power can be given as shown in the following table.

Referring to Table 6, surplus power is in the range of -23dB to + 40dB. If 6 bits are used to represent the residue power, 64 (= 2 ⁶ ) kinds of indexes can be represented, and the total power is divided into 64 levels. For example, if the bit representing the redundant power is "0"("000000" if represented by 6 bits), it indicates that the level of the redundant power is "-23≤P _PH ≤ -22 dB".

On the other hand, control of the surplus power report is possible through a periodic surplus power reporting timer (periodicPHR-Timer, hereinafter referred to as a "periodic timer") and a blocking timer (prohibitPHR-Timer). By transmitting the "dl-PathlossChange" value through the RRC message, triggering of the surplus power report due to the change of the path loss value measured by the UE in downlink and the change of the power backoff request value (P-MPR) by the power management To control.

The surplus power report may be triggered when at least one of the following events occurs.

1. A path loss value (eg, measured by the UE in at least one active serving cell used as a path loss reference after the UE secures uplink resources for new transmission and proceeds with the last surplus power report transmission). Surplus power is reported when the path loss estimate is changed larger and the cutoff timer expires, or when the cutoff timer expires and the path loss value (dB) changes by more than one change in at least one active serving cell used as a pathloss reference. Is triggered. The path loss estimate may be measured by the terminal based on the RSRP.

2. When the periodic timer expires, the surplus power report is triggered. Since the surplus power changes from time to time, according to the periodic surplus power reporting method, the terminal triggers the surplus power report when the periodic timer expires, and restarts the periodic timer if the surplus power is reported.

3. When the configuration or reconfiguration related to the surplus power reporting operation except the prohibition is made by a higher layer such as RRC or MAC, surplus power reporting is triggered.

4. When the secondary serving cell configured with uplink is activated, the surplus power report is triggered.

5. When the UE secures uplink resources for new transmission, any of the activated serving cells configured with uplink transmits the last surplus power report when uplink data transmission or PUCCH transmission through the uplink resources in the corresponding TTI. If the resource allocation for uplink transmission or the PUCCH transmission exists in the cell after proceeding, and the change of the power backoff request value (P-MPR _c ) after the last surplus power report transmission is "dl" If greater than the value -PathlossChange "[dB], surplus power reporting is triggered.

As an example of triggering, when a UE is allocated a resource for new transmission for a corresponding TTI, the following three steps are performed.

(1) In the case of the first uplink resource allocation for new transmission after the last MAC reset, a periodic timer is started.

(2) At least one surplus power report has been triggered since the last surplus power report transmission or the surplus power report transmitted is the first triggered surplus power report, and the allocated uplink resources are the surplus power report MAC control element (extended PHR). In the case of providing sufficient space for transmitting),

1) If the extended PHR is configured, each uplink is configured and obtains a type 1 surplus power value for the activated serving cell, and if the UE is uplink for uplink transmission through the corresponding serving cell for the corresponding TTI If the link resource allocation is received _, a value corresponding to the P _{CMAX , c} field is obtained from the physical layer, and an extended PHR MAC CE (Extended Power Headroom Report MAC Control Element) is generated and transmitted.

2) If, and is an extended PHR configuration, if simultaneousPUCCH-PUSCH is configured, obtains the type 2 surplus power value for the primary serving cell, if the UE for the PUCCH transmission in the TTI from the PHY layer P _{CMAX, Get} the value corresponding to field _c . Then, the extended PHR MAC CE is generated and transmitted.

3) If the extended PHR is not configured, the type 1 surplus power value is obtained from the physical layer, and the surplus power report MAC control element is generated and transmitted.

(3) The terminal starts or restarts a periodic timer, starts or restarts a shutdown timer, and cancels all triggered surplus power reports.

On the other hand, the extended PHR MAC CE is identified by the LCID in the subheader of the MAC PDU. The extended PHR MAC CE may have various sizes.

8 shows an example of an extended PHR MAC CE to which the present invention is applied.

Referring to FIG. 8, C _i Field means SCellIndex i. If "1", the PH value is reported from the secondary serving cell; if "0", the PH value is not reported from the secondary serving cell. do. The R field is a reserved bit and is set to zero.

In addition, the V field is an indicator indicating whether the PH value based on the actual transmission or the PH value for the reference format. In the case of Type1 redundancy report, V = 0 indicates that there is actual PUSCH transmission, and V = 1 indicates that a PUSCH reference format is used. In the case of Type 2 redundant reporting, V = 0 indicates that there is an actual PUCCH transmission, and V = 1 indicates that a PUCCH reference format is used. For Type 1 redundant report and Type 2 redundant report, V = 0 indicates that there is a related P _{CMAX , c} field, and V = 1 indicates that the associated P _{CMAX , c} field is omitted.

The PH (Power Headroom) field is a field for surplus power and may be 6 bits.

The P field indicates whether the terminal has applied power backoff (P-MRP) by power management. If the value of the P _{CMAX , c} field is different due to the power backoff _, P = 1 is set.

The P _{CMAX , c} field may be P _{CMAX , c} or used to calculate the preceding PH field.

This field value may or may not exist.

Table 7 below shows the nominal UE transmit power levels for the extended PHR.

Now, a physical non-synchronized random access procedure is described.

In view of the higher layers, the Level 1 (L1) random access procedure includes the transmission of the random access preamble and the random access response. The L1 random access procedure refers to a random access procedure performed at the physical layer. That is, this is a random access procedure step in which new signaling of the physical layer to be defined for random access is included. For example, in the case of a random access preamble, a signal to be defined in the physical layer only for random access and the PDCCH scrambled with RA-RNTI is also a physical layer message format defined only for random access. The remaining messages are scheduled for transmission in the shared data channel by higher layers and are not considered part of the L1 random access procedure. The random access channel occupies 6 resource blocks in one subframe or a set of consequtive subframes reserved for random access preamble transmission. The base station is not prohibited from scheduling data among the resource blocks reserved for random access preamble transmission.

The L1 random access procedure requires the following procedures.

1. Triggered by a request for preamble transmission by higher layers.

2. As part of the request, the higher layer indicates the preamble index, the target preamble receive power (PREAMBLE_RECEIVED_TARGET_POWER), the corresponding RA-RNTI (or C-RNTI) and PRACH resources.

3. The preamble transmit power P _PRACH is determined by the following equation.

Here, P _{CMAX , c} (i) is a terminal transmission power set for subframe i of the main serving cell, and PL _c is a downlink path loss prediction value for the main serving cell calculated by the terminal.

4. The preamble sequence is selected from a preamble sequence set using the preamble index.

5. A single preamble is transmitted using a preamble sequence selected as transmit power P _PRACH in the indicated PRACH resources.

6. Detecting PDCCH as indicated RA-RNTI (or C-RNTI) is attempted during the window controlled by the upper layer. If the PDCCH is detected, the corresponding DL-SCH transport block is delivered to a higher layer. Upper layers parse the transport block and indicate a 20-bit uplink grant to the physical layer.

According to the existing random access procedure, the extended PHR including PH and P _{CMAX , c} values are transmitted for all activated serving cells. Furthermore _, it is efficient to check whether the TAG including the activated serving cell acquires uplink synchronization and transmit PHR including PH and P _{CMAX , c} information for the activated serving cell in the TAG.

First, in the extended PHR, secondary serving cells in the sTAG that do not acquire a valid TA value for uplink, even if activated, are not included in the corresponding PHR target during PHR triggering and fail to obtain a valid TA value for uplink. The secondary serving cells in the sTAG are not related to the conditions related to PHR triggering.

9 is a block diagram illustrating a structure of a random access response message according to an embodiment of the present invention.

Referring to FIG. 9, the random access response message may be configured in the format of MAC PDU 900. The MAC PDU 900 includes a MAC header 910, at least one MAC control element (CE), 920-1,..., 920-n, and at least one MAC SDU (Service Data Unit). 930-1,..., 930-m) and padding 940.

MAC control elements 920-1,..., 920-n are control messages generated by the MAC layer.

The MAC header 910 includes at least one subheader 910-1, 910-2, 910-3, 910-4, ..., 910-k, and each subheader 910-k. 1, 910-2, 910-3, 910-4, ..., 910-k correspond to one MAC SDU or one MAC control element or padding 940. The order of subheaders 910-1, 910-2, 910-3, 910-4, ..., 910-k is the corresponding MAC SDU 930-1, ... 930 in MAC PDU 900. m), MAC control elements 920-1, ..., 920-n) or padding 940 in the same order.

Each subheader 910-1, 910-2, 910-3, 910-4, ..., 910-k includes four fields, such as R, R, E, LCID, or R, R, E It can contain six fields: LCID, F, L. Subheaders containing four fields are subheaders corresponding to MAC control elements 920-1, ..., 920-n or padding 940, and subheaders containing six fields are MAC SDUs 930. Subheader corresponding to -1, ..., 930-m).

10 shows an example of a subheader of a MAC PDU to which the present invention is applied.

Referring to FIG. 10, the subheader of the MAC PDU includes four fields, R, R, E, and LCID fields. The R field and the E field are 1 bit, and the LCID is 5 bits.

The Logical Channel ID (LCID) field may identify a logical channel corresponding to the MAC SDUs 930-1,..., 930-m or MAC control elements 920,..., 920-m. ) Or an identification field for identifying the type of padding, and each subheader 910-1, 910-2, 910-3, 910-4, ..., 910-k has an octet structure. When having, the LCID field may be 5 bits.

For example, the LCID field indicates whether the MAC control elements 820-1, ..., 820-n are MAC control elements for indicating activation / deactivation of the serving cell as shown in the following table. Contention Resolution Identity Identifies whether it is a MAC control element or a MAC control element for time advance commands. The MAC control element for the time forward command is the MAC control element used for time alignment in random access.

Referring to Table 8, if the value of the LCID field is 11001, the corresponding MAC control element is a MAC control element for the extended PHR. If the value of the LCID field is 11010, the corresponding MAC control element is a MAC control element for PHR.

Now, parallel transmission of a terminal will be described.

Parallel transmission of a UE is a PUSCH, PUCCH, or SRS in a serving cell other than the primary serving cell or secondary serving cell in which the PRACH is transmitted in all or some intervals in which the PRACH is transmitted from the terminal through the primary serving cell or secondary serving cell. Say the situation in which it is sent.

The case where the parallel transmission of the UE occurs in the same subframe is called a full overlapping case, and the case where the parallel transmission of the UE occurs in different subframes due to different time advance values is partially overlapped. (partial overlapping case).

The power limited case and the non-power limited case will now be described.

The power limit case refers to a state in which the required transmission power is limited because the required transmission power of the terminal indicated by the base station is higher than the maximum transmission power that the terminal can transmit when the terminal performs uplink transmission. In performing the surplus power report, a negative surplus power value is reported.

On the other hand, the non-power limited case refers to a state in which the required transmit power is not limited because the required transmit power of the terminal indicated by the base station is lower than the maximum transmit power that the terminal can transmit when the terminal performs uplink transmission. In performing the surplus power report, a positive power surplus value is reported.

Now, power scaling will be described. Power scaling refers to a decrease in transmission power by a certain ratio in order to allocate power so as not to exceed the total transmission power of the terminal. Power scaling may be expressed in various ways, such as power regulation, power scaling, power regulation.

The total transmit power of the terminal

If exceeded, the UE for the serving cell c of subframe i

Is scaled as follows.

Referring to Equation (10)

Is the linear value of P _PUCCH (i),

Is a linear value of P _{PUSCH, c} (i),

Is the maximum configured maximum output power P _CMAX configured in the terminal in subframe i, w (i) is for the serving cell c

A scaling factor of (which may be referred to as a scaling factor, or scaling factor), and has a value between 0 and 1. If there is no PUCCH transmission in subframe i,

to be.

UE has PUSCH transmission with uplink control information (UCI) in serving cell j, PUSCH transmission without UCI in any of the remaining serving cells, and total transmit power of UE

Exceeded, the UE for the serving cells without UCI of subframe i

Is scaled as follows.

here,

Is the PUSCH transmit power for the cell with UCI, w (i) is for the serving cell c without UCI

Is a scaling factor of.

Unless

The scaling index is not applied to the total transmit power of the terminal.

Exceeds. At this time, if w (i) is greater than 0, the w (i) value is the same for the serving cells, w (i) is 0 for the particular serving cells.

The UE simultaneously transmits a PUSCH with UCI for PUCCH and serving cell j (simultaneous), transmits a PUSCH without UCI in any of the remaining serving cells, and total transmit power of the UE

If exceeds, the terminal

Is obtained as in the following equation.

On the other hand, when parallel transmission of the terminal is performed, the priority of power scaling in the power limit case is as follows.

Referring to Equation 13, 1) PRACH power is allocated with the highest priority and then PUCCH / PUSCH power is allocated. 2) In the full overlap case, power scaling is performed on OFDM symbols of all subframes. 3) In the case of the partial overlap case, power scaling is performed only on overlapping OFDM symbols for all or part of the interval. If the partial overlapping interval is within one OFDM symbol interval, the corresponding OFDM symbol is not transmitted.

Now, a power scaling method for parallel transmission applied to the present invention will be described.

(1) parallel transmission of PRACH and PUSCH

If the total transmit power of the terminal

If more than and there is no PUCCH transmission, the UE for the serving cell c of subframe i

Is scaled as follows.

here,

Is the linear value of P _PRACH (i),

Is a linear value of P _{PUSCH , c} (i),

Is a linear value of the terminal maximum transmit power P _CMAX and w (i) is for the serving cell c.

Is the scaling index value of.

Here, when there is a PUSCH with UCI, the linear value of the PUSCH transmission power with the UCI for the serving cell j of the subframe i

Is scaled with the following equation

(2) parallel transmission of PRACH, PUSCH and PUCCH

If the total transmit power of the terminal

If more than and PUCCH transmission is included, the UE first of all the linear value of the PUCCH transmit power for the main serving cell of subframe i

Is scaled as follows.

here,

Is a linear value of P _PUCCH (i).

If power scaling for the PUCCH occurs, the PUSCH is not transmitted. On the other hand, when the power scaling for the PUCCH does not occur, the UE power scales the PUSCH for the serving cells c, j as shown in the following equation.

Meanwhile, in the system in which carrier aggregation is applied as shown in FIGS. 2 to 4, when the random access procedure is performed in the secondary serving cell to apply the M-TA as shown in FIGS. 5 to 7, the UE transmits PRACH to the base station. Simultaneously with transmission, the PUSCH (or PUCCH) including the surplus power report (PHR) may be transmitted in parallel.

However, when the transmission power (or PUCCH, or PUCCH and PUSCH) of the PUSCH is scaled as in Equation 14 to Equation 17 due to such parallel transmission, (1) MPR calculation error, and (2) base station scheduling And power scaling errors may occur. This will be described in detail below.

(1) MPR calculation error

The terminal first sets a value of P _{CMAX , c in} order to calculate surplus power (PH _{, c} ) for the serving cell c. At this time, the value that most affects the value of P _{CMAX, c} is an MPR value.

The MPR value may be changed according to a serving cell in which actual transmission is performed after carrier aggregation. If the PRACH is transmitted in a specific secondary serving cell, since the actual transmission is performed, the MPR values of the serving cells in which PUCCH or PUSCH transmitted simultaneously with the PRACH may be changed.

In addition, when there is a PUCCH or a PUSCH that is not scaled due to power scaling due to PRACH transmission, a combination of serving cells that are actually transmitted may be changed so that an MPR value may be changed. The calculation is not based on the value of P _{CMAX , c} which is changed due to PRACH transmission. Therefore, an error may occur when calculating the MPR for the serving cell c.

11 shows an example of an MPR calculation error applied to the present invention.

Referring to FIG. 11, in a subframe in which PRACHs are not transmitted in parallel, a PUSCH 1115 having UCI is transmitted through the frequency band F2 in the RF1 1100, and a PUSCH 1155 without UCI in the frequency band F3 in the RF2 1150. ). That is, one channel is transmitted from each of the RF1 1100 and the RF2 1150.

However, if the UE transmits the PRACH 1110 prior to the PUSCH 1155 without UCI, there is no transmission in the RF2 1150, and the PRACH 1110 is transmitted through the frequency band F1 in the RF1 1100 and the frequency band. The PUSCH 1115 with UCI is transmitted in parallel through F2.

At this time, since two channels are transmitted by one RF (RF1, 1100), the MPR value is increased and the P _{CMAX , c} value is changed. Therefore, the surplus power value of the terminal is also changed. However, because the base station does not detect the MPR change, an error may occur.

As such _, when there is an MPR value changed by PRACH transmission when P _{CMAX , c is} calculated, the UE for calculating an actual PH value (type 1 or type 2) reflects the changed MPR value for the serving cell c. Must be calculated.

For example, when the base station receives the PHR in the subframe scheduled for the serving cells 2 and 3, if the PH value is a positive value, the base station may determine that there is no transmission power scaling and determine that all actual transmissions have occurred. On the other hand, the actual transmission of the UE may not be PUSCH transmission of the serving cell 2 by the PRACH generated in the serving cell 4. In this case, the P _{CMAX , c} value for the serving cells 2 and 3 is set to a value that appears when the actual transmission is made in the serving cells 3 and 4, and the distortion in which the PH value calculated based on the P _{CMAX , c} is transmitted. Occurs.

(2) Base station scheduling and power scaling error

The terminal may be placed in a power limit case by performing PRACH transmission. At this time, the transmission power of the PUCCH or PUSCH actually transmitted may be reduced. However, when calculating the PH, the reduced transmission power may not be reflected. In other words, it should actually be a negative PH value (in dB, hereinafter referred to as "N [dB]"), but the transmission power required for PRACH transmission because the influence on the transmission power consumed for PRACH transmission is not reflected. Is set to a positive PH value (in dB, hereinafter referred to as "M [dB]"). The M [dB] value is distorted information. The PH value to be provided to the actual base station is N [dB], but the M value is reported due to the transmission power reduced by a scaled value by PRACH (hereinafter referred to as "K [dB]") (where , "N + K = M").

Therefore, the base station may cause an error in operation because the PH information is distorted. For example, the base station determines that the transmission power of the current PUCCH or PUSCH is low, and since the PH value is reported as a high value, the base station may increase the transmission power based on the M [dB] value. As a result, the transmission power of the PUCCH or the PUSCH in the corresponding serving cell is sufficiently secured. However, the transmission power for the transmission of the PUSCH or the like in another serving cell may not be secured.

12 illustrates an example of a power scaling error applied to the present invention.

Referring to FIG. 12, power is allocated for a secondary serving cell 1 (SCell1) and a secondary serving cell 2 (SCell2) within a transmission capability of a terminal, and then, power must be allocated for a PRACH having a priority higher than that of a PUCCH or a PUSCH. In this case, power for the secondary serving cell 2 (SCell2) and the PRACH is sufficiently secured, but a problem may occur that transmission power for transmission of the secondary serving cell 1 (Scell1) may not be secured.

In addition, since the base station cannot know the value of K [dB], the error operation for power scaling is continuously performed until the triggered information is transmitted to the base station or the periodic timer (periodic PHR-timer) expires after the cutoff timer expires. You can go ahead and this can make matters worse.

On the other hand, in the situation where the base station and the terminal supports parallel transmission, due to the effect of pathloss, the more terminals exist at the cell boundary, the higher the amount of transmission power required for PRACH transmission. For example, about 50% of terminals corresponding to 0.7 or more may exist based on a cell radius 1.

Now, a method of parallel transmission of a PHR and a PRACH by a terminal without an error (MPR error, power scaling error of a base station) due to power scaling according to the present invention will be described.

According to the present invention, when the terminal proceeds to the parallel transmission of the PRACH and PUSCH (or PUCCH, or PUCCH and PUSCH) in a specific subframe based on the command of the base station, the power limited case in which the required transmission power of the terminal is limited If it is determined that the terminal (although the PHR is triggered to transmit the PHR through the PUSCH), the terminal limits the transmission of the PHR

As such, the method of reporting PHR in a limited power case may be applied to PHR triggering conditions (Example 1) or may be applied to blocking of PHR (Example 2).

Embodiment 1 In a power limiting case, PHR may be limited through a PHR triggering condition of a terminal.

1) The UE does not perform PHR triggering when at least one PUSCH transmission is not substantially performed among the plurality of PUSCHs due to PRACH transmission.

2) The UE does not perform PHR triggering when the transmit power of the PUSCH is scaled due to PRACH transmission. Scaling transmission power means transmission power attenuation.

That is, despite the PRACH transmission, PHR triggering of the UE is performed when all the PUSCHs are substantially transmitted and the transmission power of the PUSCHs is not scaled.

PHR triggering conditions according to an embodiment of the present invention are as follows. This is the case where the UE is allocated a resource for new transmission with respect to the TTI.

(1) If it is the first uplink resource allocation for a new transmission after resetting the last MAC, a periodic PHR-Timer is started.

(2) if the PHR procedure since the last PHR transmission is at least one PHR triggered or this is the first triggered PHR, enough space for the allocated uplink resources to transmit the PHR MAC CE (or extended PHR MAC CE). If the extended PHR is configured and power scaling does not occur due to the RA preamble transmission of a specific serving cell, 1) each uplink is configured and type 1 surplus for the activated serving cell. Acquires a power value, and if a UE receives an uplink resource allocation for uplink transmission through a corresponding serving cell to a corresponding TTI, obtains a value corresponding to a P _{CMAX , c} field from a physical layer; and 2) if simultaneousPUCCH- If the PUSCH is configured, the type 2 surplus power value for the primary serving cell is obtained, and if the UE transmits the PUCCH to the corresponding TTI, the physical layer From obtains a value corresponding to P _{CMAX, c} field, 3) to produce an extended PHR MAC CE is sent.

(Embodiment 2) In the power limiting case, the terminal may selectively block transmission of the extended PHR to limit the PHR.

1) Transmission of a PHR (or an extended PHR) is blocked when at least one PUSCH transmission of a plurality of PUSCHs is not substantially performed due to PRACH transmission.

2) When the transmission power of the PUSCH is scaled due to the PRACH transmission, transmission of the PHR (or extended PHR) is blocked.

13 is a flowchart illustrating surplus power reporting between a terminal and a base station according to the present invention.

Referring to FIG. 13, the base station transmits a PDCCH command to the terminal (S1300). Random access preamble assignment is performed. In this case, the PDCCH command may be transmitted through L1 (layer 1). The random access procedure is performed due to the PDCCH command. For example, the PDCCH command may be allocated and transmitted to the control information region of the secondary serving cell in which the random access procedure is to be performed. As another example, the terminal may receive a type of random access procedure indicator other than the PDCCH command from the base station. In this case, a random access procedure may proceed based on the random access procedure indicator.

Subsequently to step S1300, the UE confirming the activation of the serving cell (sub-serving cell) performs PHR triggering in consideration of power scaling (S1305).

Upon receiving the PDCCH command for any secondary serving cell, the UE triggers the PHR when the PHR triggering condition is met (or when an event that is a triggering requirement occurs). In this case, the event which is a requirement of the triggering may include a path loss change amount, a power backoff change amount, various timers, and the like. These may constitute triggering requirements in association with each other or independently.

In addition, PHR triggering according to an embodiment of the present invention is performed only when an error due to power scaling does not occur when parallel transmission is performed.

First, the UE checks whether parallel transmission is performed in a PHR-triggered subframe. That is, the UE checks the time position of the PFR triggered subframe and checks whether the PHR and the PRACH are transmitted in parallel.

If the parallel transmission is performed, the UE performs PHR triggering only when all PUSCHs are substantially transmitted and the transmission power of the PUSCHs is not scaled. That is, the UE performs PHR triggering only when an error according to power scaling does not occur.

PHR triggering conditions according to another embodiment of the present invention are as follows. This is the case where the terminal is allocated a resource for new transmission for the corresponding TTI.

(1) If it is the first uplink resource allocation for a new transmission after resetting the last MAC, a periodic PHR-Timer is started.

(2) if the PHR procedure since the last PHR transmission is at least one PHR triggered or this is the first triggered PHR, enough space for the allocated uplink resources to transmit the PHR MAC CE (or extended PHR MAC CE). If the extended PHR is configured and power scaling does not occur due to RA preamble transmission of a specific serving cell,

1) Each type of uplink is configured and obtains a type 1 surplus power value for the activated serving cell, and if the terminal receives uplink resource allocation for uplink transmission through the corresponding serving cell to the corresponding TTI, Obtains the value corresponding to P _{CMAX , c} field,

2) If simultaneousPUCCH-PUSCH is configured, obtain a Type 2 surplus power value for the primary serving cell, and if the UE transmits PUCCH to the corresponding TTI, obtain a value corresponding to the P _{CMAX , c} field from the physical layer. And 3) generate and transmit the extended PHR MAC CE.

Following step S1305, the terminal configures a PHR to be transmitted to the base station (S1310).

The terminal configures the PHR to include the PH value or P _{CMAX , c} value of the activated serving cells. In step S1305, the PH value is a value in which no error occurs due to power scaling.

Following step S1310, the terminal transmits the PRACH and the PHR in parallel to the base station (S1315). At this time, the PRACH may be transmitted through L1 (Layer 1), and the PHR may be transmitted in the form of an extended PHR MAC CE. That is, PRACH and PHR are simultaneously transmitted in parallel in different messages.

In particular, the UE can transmit a random access preamble to the base station through the PRACH. The random access preamble is transmitted through the uplink of the serving cell based on the PDCCH command received from the base station. That is, the random access preamble is transmitted through the uplink of the secondary serving cell based on the PDCCH command information received from the base station.

Subsequently, the random access response to the random access preamble may be transmitted to the terminal through the downlink component carrier of the main serving cell. That is, the PDCCH, which is a random access response grant, is transmitted through a common search space of the main serving cell. At this time, the RA-RNTI value may be calculated in the terminal and the base station in the following equation (18).

Here, t _id denotes a position (0 to 9) of an uplink subframe in which the random access preamble is transmitted, and f _id denotes an index (0 to 5) of the frequency band in which the random access preamble is transmitted.

Since the random access response grant is transmitted to the primary serving cell, the PDSCH including the random access response MAC PDU information is also transmitted to the primary serving cell.

14 is a block diagram illustrating a structure of a random access response message according to another example of the present invention.

Referring to FIG. 14, the random access response message may be configured in the format of the RAR MAC PDU 1400. The RAR MAC PDU 1400 includes a MAC header 1410, at least one MAC RAR field 1415-1,..., 1141-n, and padding 1440.

The MAC header 1410 includes at least one subheader 1405-1, 1405-2,..., 1405-n, and each subheader 1405-1, 1405-2,. n) corresponds to each MAC RAR field 1415-1, ..., 1141-n. The order of the subheaders 1405-1, 1405-2,..., 1405-n is the corresponding MAC RAR fields 1415-1, 1415-2,... 1141 in the RAR MAC PDU 1400. n) may be arranged in the same order.

Meanwhile, the MAC header 1410 may further include a backoff indicator (BI) subheader 1401. The backoff indicator (BI) subheader 1401 includes a backoff indicator. The MAC RAR field corresponding to the backoff indicator subheader 1401 is not present in the RAR MAC PDU 1400. However, the backoff indicator subheader 1401 is a parameter that is commonly applied to all terminals that receive the random access response message. If the UE has never received the backoff indicator, the backoff parameter becomes '0ms' as an initial value or a default value.

The backoff indicator subheader 1401 may be included in the RAR MAC PDU 1400 only when the base station needs to change the backoff parameter for the corresponding serving cell. For example, when the random access preamble transmission through the serving cell is more than a predetermined level or when the base station continuously fails to receive the random access preamble, the base station uses a backoff indicator subheader 1401 that increases the backoff parameter value. It may be included in the RAR MAC PDU 1400 and transmitted.

The backoff indicator subheader 1401 may include five fields, such as E, T, R, R, and BI. Here, the E field is a field indicating whether the corresponding subheader is the last subheader or not. The T field is a field indicating whether the corresponding subheader is a subheader including a random access preamble ID (RAPID) or a backoff indicator subheader. In addition, the R field indicates a reserved bit. The BI field is defined with 4 bits. The BI field value indicates one of sixteen index values. The BI field may be applied when the terminal determines that the random access procedure is not successful.

The RAPID is information for confirming whether or not the RAR MAC PDU for the random access preamble transmitted by the corresponding terminal among the random access preambles transmitted through the same time / frequency resource by the multiple terminals. Subheaders 1405-1, 1405-2,..., 1405-n that include a RAPID may include three fields: E, T, and RAPID. Here, the E field is a field indicating whether the corresponding subheader is the last subheader or not. The T field is a field indicating whether the corresponding subheader is a subheader including a RAPID or a backoff indicator subheader. The RAPID field is defined by 6 bits and represents information about a random access preamble allocated by the base station or a random access preamble selected by the terminal.

15 is an example of a MAC subheader applied to the present invention.

Referring to FIG. 15, it corresponds to MAC subheaders 1405-1, 1405-2,..., 1405-n included in the RAR MAC PDU of FIG. 14.

16 is an example of a MAC control element to which the present invention is applied.

Referring to FIG. 16, a MAC control element having an octet structure (8 bits) is a MAC control element composed of six octets.

The MAC control element includes a 1-bit R field, a 11-bit time forward command field, and a 20-bit uplink grant. It also contains a 16-bit temporary C-RNTI field. The uplink grant information is UL resource allocation information of the serving cell that has transmitted the preamble corresponding to the RAPID value.

17 is a flowchart illustrating another example of surplus power report between a terminal and a base station according to the present invention.

Referring to FIG. 17, the base station transmits a PDCCH command to the terminal (S1700). Random access preamble allocation is performed. At this time, the PDCCH command may be transmitted through L1. The random access procedure is performed due to the PDCCH command.

Subsequently to step S1700, the terminal confirming the activation of the serving cell (secondary serving cell) performs PHR triggering (S1705).

Upon receiving the PDCCH command for any secondary serving cell, the UE triggers the PHR when the PHR triggering requirement is satisfied (or when an event that is a triggering requirement occurs). In this case, the event which is a requirement of triggering may include a path loss change amount, a power backoff change amount, various timers, and the like. These may constitute triggering requirements in association with each other or independently.

Subsequently to step S1705, the terminal determines whether to transmit the PHR in consideration of power scaling, and configures the PHR (S1710).

Even in the case of PHR triggering, the UE may determine whether to transmit the extended PHR and selectively block to prevent an error due to power scaling in the power limited case.

For example, the UE blocks transmission of a PHR (or extended PHR) when at least one PUSCH transmission is not substantially performed among a plurality of PUSCHs due to PRACH transmission.

As another example, when the transmission power of the PUSCH is scaled due to the PRACH transmission, the terminal blocks the transmission of the PHR (or the extended PHR).

If the transmission of the PHR is not blocked, the terminal configures the PHR to include the PH value or P _{CMAX , c} value of the activated serving cells. The PH value is a value in which no error occurs due to power scaling.

Following step S1710, the terminal transmits the PRACH and the configured PHR in parallel to the base station (S1715). At this time, the PRACH is transmitted through L1, and the PHR is transmitted in the form of an extended PHR MAC CE. That is, PRACH and PHR are simultaneously transmitted in parallel in different messages.

The terminal transmits the random access preamble to the base station through the PRACH. The random access preamble is transmitted through the uplink of the serving cell based on the PDCCH command received from the base station.

18 is a flowchart illustrating an example of an operation of a terminal performing PHR transmission in consideration of power scaling according to the present invention.

Referring to FIG. 18, if the terminal operates in a carrier aggregation system (S1800) and transmits a PRACH in parallel with a PUSCH or a PUCCH (S1805), and if power scaling is not performed (S1810), the terminal may include a PRACH and PHR is transmitted in parallel (S1815).

On the other hand, if the UE operates in the carrier aggregation system (S1800) and transmits the PRACH in parallel with the PUSCH or the PUCCH (S1805), but if power scaling is performed (S1810), the UE does not perform PHR triggering or PHR triggering. Even if the PHR is blocked, only the PRACH is transmitted (S1820).

19 is a flowchart illustrating another example of an operation of a terminal performing PHR transmission in consideration of power scaling according to the present invention.

Referring to FIG. 19, the terminal receives a PDCCH command from the base station (S1900). Random access preamble allocation is performed, and the PDCCH command may be transmitted through L1. A random access procedure is performed due to the PDCCH command.

For example, the PDCCH command may be allocated and transmitted to the control information region of the secondary serving cell in which the random access procedure is to be performed. In this case, the random access procedure may be performed through the secondary serving cell.

When the random access procedure is performed through the secondary serving cell, it is determined whether parallel transmission is performed because all or part of the subframe where the PRACH is transmitted and the PHR-triggered subframe time position are the same (S1905).

If the parallel transmission is not performed (S1910), since the enhancement error does not occur due to power scaling, the existing operation is performed.

Subsequently to step S1905, the terminal confirming whether the serving cell on which the random access procedure is performed is an activated serving cell (or secondary serving cell) performs PHR triggering (S1915).

As an example, the UE performs PHR triggering only when an error according to power scaling does not occur.

As another example, the UE performs PHR triggering only when all the PUSCHs are substantially transmitted and the transmission power of the PUSCHs is not scaled.

If the terminal does not transmit the PHR because PHR triggering is not performed, or if the PHR triggering is separately determined not to transmit the PHR, but does not transmit the PHR (S1920), the terminal transmits only the PRACH to the base station (S1935).

For example, in the power limit case, the UE selectively blocks transmission of the PHR (or the extended PHR) and thus does not transmit the PHR due to an error due to power scaling.

As another example, the UE blocks transmission of a PHR (or extended PHR) when at least one PUSCH transmission is not substantially performed among a plurality of PUSCHs due to PRACH transmission.

As another example, the UE blocks transmission of PHR (or extended PHR) when the transmission power of the PUSCH is scaled due to PRACH transmission.

If the terminal determines to transmit the PHR in step S1920, the terminal configures the PHR to include the surplus power (PH) value and P _{CMAX , c} information of the activated serving cells (S1925).

Subsequently, the terminal transmits the PRACH and the PHR in parallel to the base station (S1930). At this time, the PRACH may be transmitted through L1, and the PHR may be transmitted in the form of an extended PHR MAC CE. That is, PRACH and PHR are simultaneously transmitted in parallel in different messages. In particular, the UE can transmit a random access preamble to the base station through the PRACH. The random access preamble is transmitted through the uplink of the serving cell based on the PDCCH command received from the base station.

20 is a flowchart illustrating the operation of a base station according to the present invention.

Referring to FIG. 20, the base station transmits a PDCCH command to the terminal for a random access procedure (S2000). Through this, random access preamble allocation is performed. At this time, the PDCCH command may be transmitted through L1. For example, the PDCCH command may be allocated and transmitted to the control information region of the secondary serving cell in which the random access procedure is to be performed.

The base station receives a surplus power report (PHR) from the terminal (S2005). At this time, the PHR may be transmitted in the form of an extended PHR MAC CE. At the same time, the PRACH may be transmitted in parallel with the PHR.

For example, the PHR may include a PH value or P _{CMAX , c} value of activated serving cells.

For example, a random access preamble for the PDCCH command may be received through the PRACH.

The base station applies the PH to the scheduling for the terminal based on the received PHR (S2010).

For example, the base station may include the scheduling information applying the PH based on the PHR to the random access response to the random access preamble to the terminal.

21 is a block diagram illustrating a terminal and a base station according to an embodiment of the present invention.

Referring to FIG. 21, the terminal 2100 includes a receiver 2105, a PHR triggering unit 2110, a PHR determination unit 2115, and a transmitter 2120.

The receiver 2105 receives a PDCCH command from the base station 2150. At this time, the PDCCH command may be received through L1. For example, the PDCCH command may be allocated and received in the control information region of the secondary serving cell in which the random access procedure is to be performed.

The terminal 2100 performs a random access procedure based on the PDCCH command.

After the terminal 2100 checks whether the serving cell (sub-serving cell) is activated, the PHR triggering unit 2110 performs PHR triggering in consideration of power scaling.

The PHR triggering unit 2110 triggers the PHR when the PHR triggering requirement is satisfied (or when an event that is a triggering requirement occurs). In this case, the event which is a requirement of triggering may include a path loss change amount, a power backoff change amount, various timers, and the like. These may constitute triggering requirements in association with each other or independently.

As an example, the PHR triggering unit 2110 triggers the PHR only when an error due to power scaling does not occur when parallel transmission of the PHR and the PRACH is performed. In this case, the UE 2100 may determine whether parallel transmission is performed in the PHR-triggered subframe through the time position of the PHR-triggered subframe.

If parallel transmission is performed, the PHR triggering unit 2110 performs PHR triggering only when all PUSCHs are substantially transmitted and the transmission power of the PUSCH is not scaled.

The terminal 2100 may further include a PHR configuration unit, and the PHR configuration unit configures a PHR to be transmitted to the base station 2150. The PHR configuration unit configures the PHR to include the PH value or P _{CMAX , c} value of the activated serving cells.

The transmitter 2120 transmits the PRACH and the PHR in parallel to the base station 2150. Alternatively, the transmitter 2120 transmits only the PRACH to the base station 2150. At this time, the PRACH may be transmitted through L1, and the PHR may be transmitted in the form of an extended PHR MAC CE. That is, the PRACH and the PHR may be simultaneously transmitted in parallel in different messages.

The transmitter 2120 may transmit a random access preamble to the base station 2150 through the PRACH. The transmitter 2120 transmits a random access preamble through the uplink of the serving cell based on the PDCCH command.

The receiver 2105 may further receive a random access response for the random access preamble from the base station 2150 through a downlink component carrier of the primary serving cell. The PDCCH, which is a random access response grant, may be transmitted through a common search space of the main serving cell, and the RA-RNTI value may be calculated in the same manner as in Equation 18.

Even when PHR triggering is performed, the PHR determination unit 2115 may determine whether to block transmission of the PHR (or extended PHR) in order to prevent an error due to power scaling in the power limited case. Therefore, the PHR determination unit 2115 may be called a PHR blocking unit.

For example, the PHR determination unit 2115 blocks transmission of the PHR when at least one PUSCH transmission is not substantially performed among the plurality of PUSCHs due to the PRACH transmission.

As another example, the PHR determination unit 2115 blocks transmission of the PHR when the transmission power of the PUSCH is scaled due to the PRACH transmission.

If the transmission of the PHR is not blocked (or determined to transmit the PHR), the terminal 2100 configures the PHR to include the PH value or P _{CMAX , c} value of the activated serving cells.

As such, when the terminal 2100 performs a carrier operation, corresponds to a case where the PRACH is transmitted in parallel with the PUSCH or the PUCCH, and when the power scaling is not performed, the terminal 2100 corresponds to the PRACH and Send PHR in parallel.

The base station 2150 includes a receiver 2155, a controller 2160, and a transmitter 2165.

The transmitter 2165 transmits a PDCCH command to the terminal 2100 for a random access procedure (S2000). Through this, random access preamble allocation is performed. The PDCCH command may be transmitted through L1. For example, the PDCCH command may be allocated and transmitted to the control information region of the secondary serving cell in which the random access procedure is to be performed.

The receiver 2155 receives a surplus power report (PHR) from the terminal 2100. At this time, the PHR may be transmitted in the form of an extended PHR MAC CE. At the same time, the PRACH may be transmitted in parallel with the PHR.

For example, the PHR may include a PH value or P _{CMAX , c} value of activated serving cells.

For example, a random access preamble for the PDCCH command may be received through the PRACH.

The controller 2160 may apply the PH to the scheduling of the terminal 2100 based on the received PHR.

For example, the controller 2160 may include scheduling information to which the PH is applied based on the PHR in the random access response to the random access preamble.

The foregoing description is merely illustrative of the technical idea of the present invention, and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the present invention.

Claims (12)

In a method for transmitting a power headroom report (PHR) by the terminal in a wireless communication system,
Receiving a PDCCH order (PDCCH order) indicating a random access from the base station through a physical downlink control channel (PDCCH);
Triggering the PHR based on the PHR triggering requirement;
Parallelly transmitting a physical random access channel (PRACH) including a random access preamble (PRACH), which is a response to the PDCCH command, to the base station together with the PHR;
The PHR triggering requirement is
When the PHR and the PRACH are to be transmitted in parallel in the same subframe, the transmission power of the physical uplink shared channel (PUSCH) to which the PHR is transmitted is not required to be attenuated and scaled. Surplus power report transmission method. The method of claim 1,
The PHR is,
And configured to include a surplus power value of activated serving cells or a maximum terminal outgoing power value configured for each of the serving cells. The method of claim 1,
And checking whether the PHR and the PRACH are transmitted in parallel in the subframe in which the PHR is triggered by checking a time position of the subframe in which the PHR is triggered. The method of claim 1,
The PHR is configured to report the surplus power for each of the plurality of active serving cells configured uplink, surplus power report transmission method. 5. The method of claim 4,
The surplus power report transmission method, characterized in that the required transmission power is limited because the required transmission power of the terminal to perform uplink transmission is higher than the maximum transmit power of the terminal. In a method for a terminal to perform a power headroom report (PHR) in a wireless communication system,
Receiving a PDCCH order (PDCCH order) indicating a random access from the base station through a physical downlink control channel (PDCCH);
Triggering the PHR based on the PHR triggering requirement;
In the same subframe, a physical random access channel (PRACH) including a random access preamble that is a response to the PDCCH command and a physical uplink shared channel through which the PHR is transmitted due to parallel transmission of the PHR. Blocking transmission of the PHR when the physical uplink shared channel (PUSCH) is not substantially transmitted or when the transmission power of the PUSCH to which the PHR is transmitted is attenuated and scaled; And
And when the transmission of the PHR is not blocked, transmitting the PHR and the PRACH in parallel to the base station. The method according to claim 6,
The PHR is,
And configured to include a surplus power value of activated serving cells or a maximum terminal outgoing power value configured for each of the serving cells. The method according to claim 6,
And checking whether the PHR and the PRACH are transmitted in parallel in the subframe in which the PHR is triggered by checking a time position of the subframe in which the PHR is triggered. The method according to claim 6,
The PHR is configured to report the surplus power for each of the plurality of active serving cells configured uplink, surplus power report transmission method. The method of claim 9,
The terminal
The surplus power report transmission method, characterized in that the required transmission power is limited because the required transmission power of the terminal to perform uplink transmission is higher than the maximum transmit power of the terminal. In a terminal for performing a power headroom report (PHR) in a wireless communication system,
A receiving unit for receiving a PDCCH order (PDCCH order) indicating a random access from the base station through a physical downlink control channel (PDCCH);
A PHR triggering unit for triggering a PHR based on a PHR triggering requirement;
And a transmitter configured to transmit a physical random access channel (PRACH) including a random access preamble, which is a response to the PDCCH command, to the base station in parallel with the PHR.
The PHR triggering unit,
When the PHR and the PRACH are to be transmitted in parallel in the same subframe, PHR triggering is performed with the requirement that the transmission power of the Physical Uplink Shared Channel (PUSCH) to which the PHR is transmitted is not attenuated and scaled. Terminal, characterized in that. In a terminal for performing a power headroom report (PHR) in a wireless communication system,
A receiving unit for receiving a PDCCH order (PDCCH order) indicating a random access from the base station through a physical downlink control channel (PDCCH);
A PHR triggering unit for triggering a PHR based on a PHR triggering requirement;
In the same subframe, a physical random access channel (PRACH) including a random access preamble that is a response to the PDCCH command and a physical uplink shared channel through which the PHR is transmitted due to parallel transmission of the PHR. A PHR blocking unit that blocks transmission of the PHR when the physical uplink shared channel (PUSCH) is not substantially transmitted or when the transmission power of the PUSCH through which the PHR is transmitted is attenuated and scaled; And
If the transmission of the PHR is not blocked, characterized in that it comprises a transmitter for transmitting the PHR and the PRACH in parallel to the base station.

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