KR20140118678A - Methods for transmitting and receiving reference signal in uplink and the apparatuses thereof - Google Patents

Abstract

A method for transmitting an uplink reference signal according to an embodiment of the present invention includes receiving a downlink channel including indication information necessary for transmitting a reference signal from a base station, And transmitting an uplink channel by including a reference signal in any one of sub-frames of 2N consecutive subframes, wherein N is a natural number equal to or greater than 1, and the indication information includes multiple TTIs Transmission Time Interval) or multiple sub-frame scheduling explicitly or implicitly.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for transmitting and receiving an uplink reference signal,

The present invention relates to a method for transmitting and receiving uplink data and a reference signal in a small cell or a multi-cell environment under a multi-layer cell structure, and a terminal and a base station using the method.

As communications systems evolved, consumers, such as businesses and individuals, used a wide variety of wireless terminals. The current mobile communication system such as LTE (Long Term Evolution) and LTE-Advanced of the 3GPP series is a high-speed and large-capacity communication system capable of transmitting and receiving various data such as video and wireless data beyond voice- It is required to develop a technique capable of transmitting large-capacity data in accordance with the above-described method. On the other hand, since the conventional single cell method can not be applied in transmitting uplink and reference signals in a plurality of cells or a small cell, a new technique and a method are needed.

The present invention proposes a process and an apparatus for the UE to set up such that reference signals required for uplink transmission in a plurality of cells or a small cell can maintain orthogonality. The proposed process and apparatus do not affect the operation of the existing legacy terminal and can increase the efficiency of reference signal generation and transmission of a terminal operating in a small cell environment or a plurality of cell environments.

A method for transmitting an uplink reference signal according to an embodiment of the present invention includes receiving a downlink channel including indication information necessary for transmitting a reference signal from a base station, And transmitting an uplink channel by including a reference signal in any one of sub-frames of 2N consecutive subframes, wherein N is a natural number equal to or greater than 1, and the indication information includes multiple TTIs Transmission Time Interval) or multiple sub-frame scheduling explicitly or implicitly.

A method for receiving a UL reference signal in a base station according to another embodiment of the present invention includes the steps of generating a downlink channel including indication information required for transmission of a reference signal, Wherein the terminal transmits an uplink channel by including a reference signal in any one of 2N consecutive subframes, where N is a natural number equal to or greater than 1, and the indication information includes multiple TTIs Transmission Time Interval) or multiple sub-frame scheduling explicitly or implicitly.

According to another aspect of the present invention, there is provided a terminal for transmitting an uplink reference signal, the terminal including: a receiver for receiving a downlink channel including indication information necessary for transmitting a reference signal from a base station, a controller for generating a reference signal according to the indication information, And a transmitter for transmitting an uplink channel by including a reference signal in any one of 2N consecutive subframes, wherein N is a natural number equal to or greater than 1, and the indication information is a transmission time interval (TTI) And directs the subframe scheduling explicitly or implicitly.

The base station for receiving the UL RS according to another embodiment of the present invention includes a controller for generating a downlink channel including indication information required for transmission of a reference signal and a transmitter for transmitting the generated downlink channel to the terminal Wherein the terminal transmits a UL channel by including a reference signal in any one of 2N consecutive subframes, wherein N is a natural number equal to or greater than 1, and the indication information is a multiple TTI (Transmission Time Interval) And directs multiple sub-frame scheduling explicitly or implicitly.

In the case of implementing the present invention, the UE sets up the reference signals necessary for performing uplink transmission in a plurality of cells or the small cells to maintain orthogonality, and the base station can instruct this setting. Also, since the transmission of the reference signal is adapted to the environment of a plurality of cells or a small cell, the data transmission efficiency can be increased.

1 is a view showing a small cell development according to an embodiment.
2 is a diagram showing a small cell deployment scenario.
Figure 3 is a diagram showing a detailed scenario in the small cell deployment.
4 is a diagram showing a structure of a subframe in the PUSCH transmission to which the present invention is applied.
5 is a diagram illustrating an example of a PUSCH subframe structure according to multiple TTI (or subframe) scheduling in a normal CP according to an embodiment of the present invention.
6 is a diagram illustrating an example of a PUSCH subframe structure according to multiple TTI (or subframe) scheduling in an extended CP according to an embodiment of the present invention.
FIG. 7 is a diagram illustrating a process of operating a terminal according to an embodiment of the present invention. Referring to FIG.
FIG. 8 is a flowchart illustrating a process of a base station according to an embodiment of the present invention. Referring to FIG.
9 is a diagram illustrating a configuration of a user terminal according to another embodiment of the present invention.
10 is a diagram illustrating a configuration of a base station according to another embodiment of the present invention.

Hereinafter, some embodiments of the present invention 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 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 invention rather unclear.

The wireless communication system in the present invention is widely deployed to provide various communication services such as voice, packet data and the like. A wireless communication system includes a user equipment (UE) and a base station (BS, or eNB). The user terminal in this specification is a comprehensive concept of a terminal in wireless communication. It is a comprehensive concept which means a mobile station (MS), a user terminal (UT), an SS (User Equipment) (Subscriber Station), a wireless device, and the like. Hereinafter, the user terminal may be referred to as a terminal in the present specification. Hereinafter, the user terminal may be referred to as a terminal in the present specification.

A base station or a cell generally refers to a station that communicates with a user terminal and includes a Node-B, an evolved Node-B (eNB), a sector, a Site, a BTS A base transceiver system, an access point, a relay node, a remote radio head (RRH), a radio unit (RU), a transmission point (TP), a reception point It can be called another term.

In this specification, a base station or a cell should be interpreted in a generic sense to indicate a partial region or function covered by BSC (Base Station Controller) in CDMA, NodeB in WCDMA, eNB in LTE or sector (site) , Coverage of various coverage areas such as megacell, macrocell, microcell, picocell, femtocell and relay node, RRH, RU communication range.

Since the various cells listed above exist in the base station controlling each cell, the base station can be interpreted into two meanings. i) a device itself providing a megacell, a macrocell, a microcell, a picocell, a femtocell, or a small cell in relation to a wireless region, or ii) the wireless region itself. i indicate to the base station all devices that are controlled by the same entity or that interact to configure the wireless region as a collaboration. An eNB, an RRH, an antenna, an RU, an LPN, a point, a transmission / reception point, a transmission point, a reception point, and the like are embodiments of a base station according to a configuration method of a radio area. ii) may indicate to the base station the wireless region itself that is to receive or transmit signals from the perspective of the user terminal or from a neighboring base station.

Therefore, a base station is collectively referred to as a megacell, a macrocell, a microcell, a picocell, a femtocell, a small cell, an RRH, an antenna, an RU, a low power node (LPN), a point, an eNB, Quot;

Herein, the user terminal and the base station are used in a broad sense as the two transmitting and receiving subjects used to implement the technical or technical idea described in this specification, and are not limited by a specific term or word. The user terminal and the base station are used in a broad sense as two (uplink or downlink) transmitting and receiving subjects used to implement the technology or technical idea described in the present invention, and are not limited by a specific term or word. Here, an uplink (UL, or uplink) means a method of transmitting / receiving data to / from a base station by a user terminal, and a downlink (DL or downlink) .

There are no restrictions on multiple access schemes applied to wireless communication systems. Various multiple access schemes such as Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), OFDM-FDMA, OFDM- Can be used. An embodiment of the present invention can be applied to asynchronous wireless communication that evolves into LTE and LTE-Advanced via GSM, WCDMA, and HSPA, and synchronous wireless communication that evolves into CDMA, CDMA-2000, and UMB. The present invention should not be construed as limited to or limited to a specific wireless communication field and should be construed as including all technical fields to which the idea of the present invention can be applied.

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.

In systems such as LTE and LTE-Advanced, the uplink and downlink are configured on the basis of one carrier or carrier pair to form a standard. The uplink and downlink transmit control information through a control channel such as a Physical Downlink Control Channel (PDCCH), a Physical Control Format Indicator CHannel (PCFICH), a Physical Hybrid ARQ Indicator CHannel (PHICH), a Physical Uplink Control CHannel And a data channel such as a Physical Downlink Shared CHannel (PDSCH), a Physical Uplink Shared CHannel (PUSCH), and the like. On the other hand, control information can also be transmitted using EPDCCH (enhanced PDCCH or extended PDCCH).

In this specification, a cell refers to a component carrier having a coverage of a signal transmitted from a transmission point or a transmission point or transmission / reception point of a signal transmitted from a transmission / reception point, and a transmission / reception point itself .

The wireless communication system to which the embodiments are applied may be a coordinated multi-point transmission / reception system (CoMP system) or a coordinated multi-point transmission / reception system in which two or more transmission / reception points cooperatively transmit signals. antenna transmission system, or a cooperative multi-cell communication system. A CoMP system may include at least two multipoint transmit and receive points and terminals.

The multi-point transmission / reception point includes a base station or a macro cell (hereinafter referred to as 'eNB'), and at least one mobile station having a high transmission power or a low transmission power in a macro cell area, Lt; / RTI >

Hereinafter, a downlink refers to a communication or communication path from a multipoint transmission / reception point to a terminal, and an uplink refers to a communication or communication path from a terminal to a multiple transmission / reception point. In the downlink, a transmitter may be a part of a multipoint transmission / reception point, and a receiver may be a part of a terminal. In the uplink, the transmitter may be a part of the terminal, and the receiver may be a part of multiple transmission / reception points.

Hereinafter, a situation in which a signal is transmitted / received through a channel such as PUCCH, PUSCH, PDCCH, and PDSCH is expressed as 'PUCCH, PUSCH, PDCCH and PDSCH are transmitted and received'.

In the following description, the description that the PDCCH is transmitted or received or the signal is transmitted or received through the PDCCH may be used to mean transmitting or receiving the EPDCCH or transmitting or receiving the signal through the EPDCCH.

The physical downlink control channel described below may mean a PDCCH, an EPDCCH, or a PDCCH and an EPDCCH. For convenience of description, the PDCCH, which is an embodiment of the present invention, may be applied to the PDCCH.

In addition, the high layer signaling described in this specification includes RRC signaling for transmitting RRC information including a Radio Resource Control (RRC) parameter.

An eNB, which is an embodiment of a base station, performs downlink transmission to terminals. The eNB includes a physical downlink shared channel (PDSCH) as a main physical channel for unicast transmission, downlink control information such as scheduling required for reception of PDSCH, and uplink data channel A physical downlink control channel (PDCCH) for transmitting scheduling grant information for transmission in a Physical Uplink Shared Channel (PUSCH). Hereinafter, the transmission / reception of a signal through each channel will be described in a form in which the corresponding channel is transmitted / received.

At this time, as described below with reference to the drawings, the first UE1 transmits the uplink signal to the eNB and the second UE transmits the uplink signal to the RRH.

The following describes a small cell deployment scenario to which the proposals described in the present invention can be applied.

1 is a view showing a small cell development according to an embodiment.

FIG. 1 shows a configuration in which a small cell and a macro cell coexist. In FIGS. 2 to 6, the presence or absence of macro coverage, whether the small cell is for outdoor use or indoor use, , Whether the development of the small cell is sparse or dense, or whether the same frequency spectrum as the macro is used in terms of spectrum or not.

2 is a diagram showing a small cell deployment scenario. Figure 2 shows a typical representative configuration for the scenario of Figure 3; Fig. 2 shows a small cell deployment scenario and includes scenarios # 1, # 2a, # 2b, and # 3. 200 represents a macro cell, and 210 and 220 represent a small cell. The overlapping macrocells in FIG. 2 may or may not exist. Coordination can be performed between the macro cell 200 and the small cells 210 and 220 and adjustment can also be performed between the small cells 210 and 220. And the overlapping regions of 200, 210, and 220 can be clustered.

Figure 3 is a diagram showing a detailed scenario in the small cell deployment.

The solid lines connecting the small cells in the small cells 312, 322, 332, and 342 refer to a backhaul link within the cluster. The dotted lines connecting the base station of the macro cell and the small cells in the cluster mean a backhaul link between small cells and macro cells.

310 shows the small cell deployment scenario # 1. Scenario 1 is a co-channel deployment scenario for small cells and macro cells in the presence of overhead macros and is an outdoor small cell scenario. Reference numeral 310 denotes a case where both the macro cell 311 and the small cell are outdoors, and 312 denotes a small cell cluster. Users are distributed both indoors / outdoors.

And 320 a small cell deployment scenario # 2a. Scenario 2a is a deployment scenario in which small cells and macros use different frequency spectra in the presence of an overlaid macro, and is an outdoor small cell scenario. Both the macro cell 321 and the small cells are outdoors and 322 indicates a small cell cluster. Users are distributed both indoors / outdoors.

And 330 a small cell deployment scenario # 2b. Scenario 2b is a deployment scenario in which the small cell and the macro use different frequency spectrum in the presence of the overlay macro and is an indoor small cell scenario. The macro cell 331 is outdoors, the small cells are all indoor, and 332 indicates a small cell cluster. Users are distributed both indoors / outdoors.

And 340 a small cell deployment scenario # 3. Scenario 3 is an indoor small cell scenario with no coverage of macros. 342 designates a small cell cluster. In addition, the small cells are all indoor and users are dispersed both indoors and outdoors.

The following shows a frame structure for uplink data transmission and reference signal (RS) transmission in LTE and LTE-A.

4 is a diagram showing a structure of a subframe in the PUSCH transmission to which the present invention is applied. Reference numeral 410 denotes a subframe structure in the case of PUSCH transmission and a case of a normal CP (normal CP). 411 is a first slot (1 ^st slot), 412 is a second slot (2 ^nd slot). Reference numeral 420 denotes a subframe structure in the case of PUSCH transmission and shows an extended CP case. 421 is the first slot, and 422 is the second slot.

In FIG. 4, reference numerals 410 and 420 denote the structure of a subframe for the case of PUSCH transmission. Here, the first slot and the second slot may be allocated to different frequency regions according to frequency hopping.

Hereinafter, reference signals for PUSCH data demodulation are described. In the case of a reference signal for PUSCH data demodulation, in a conventional system, a parameter for generating a reference signal transmitted from an arbitrary base station or an arbitrary cell to a terminal, that is, a sequence group index, a sequence index a terminal receives a sequence index, a cyclic shift index, and orthogonal cover code (OCC) index information from a base station to which the corresponding terminal belongs. The UE can perform the following operations: i) setting a sequence group hopping and a sequence hopping, which are set in a cell ID and an RRC configured to perform the division of the corresponding base station, according to the configuration of the sequence group hopping and the sequence hopping, And notifies the terminal of the index. Ii) a cyclic shift index (PDCCH) for generating a reference signal to be transmitted by the UE through the downlink control information (DCI) format 0 and the DCI format 4 for the uplink transmitted through the downlink, , And the OCC index. Through the procedures of i) and ii), the UE generates a reference signal for data demodulation and transmits the reference signal and the uplink PUSCH to an arbitrary base station.

In the prior art, when uplink data transmitted from a cell / base station / RRH / antenna / RU or a terminal belonging to a small cell is transmitted, a reference signal is transmitted for demodulation of a data channel, One symbol per slot is used for the uplink reference signal in the frequency domain to which the data channel is assigned or in the same frequency domain as the RBs. This is because the data rate for uplink transmission in the UE is fixedly reduced by 1/7 (14.3%) per subframe in the case of the normal CP, 1/6 (16.7%) in the case of the extended CP, ). However, in the case where the small cell environment and any cell / base station / RRH / antenna / RU can limit UE mobility to low speed, a method capable of reducing such RS overhead can be considered .

The present invention relates to an uplink data channel and a reference signal transmission method capable of reducing the overhead of a reference signal when a small cell environment and any cell / base station / RRH / antenna / RU can limit UE mobility to a low rate . The invention also relates to a method and apparatus for overlaying macrocell / base station / RRH / antenna / RU and coverage in the development of a small cell and any cell / base station / RRH / antenna / and to a method for transmitting an uplink data channel and a reference signal so as to support backward compatibility.

In case of applying multiple TTI (Multiple Transmission Time Interval) and multiple sub-frame scheduling to a small cell environment and any cell / base station / RRH / antenna / RU, multiple antennas ) Is used to transmit an uplink PUSCH using multiple layers, an OCC having a length of 2 (length-2) can be applied to maintain the orthogonality of an uplink reference signal between antennas / layers . That is, the number of SC-FDMA or DFT-spread OFDM symbols to which the UL reference signal is allocated should be designed to be a multiple of two.

Based on this, it is possible to transmit PUSCH on multiple layers as various embodiments, and it is possible to reduce an overhead of an uplink reference signal, thereby improving uplink data throughput, We will look at the structure for.

In this manner, even when existing terminals having backward compatibility exist, a new terminal, that is, a terminal performing multi-TTI (or sub-frame) scheduling and a legacy terminal performing a single sub-frame scheduling allocate resources on the same frequency resource A new terminal and a legacy terminal are multiplexed so that orthogonality of an uplink reference signal can be maintained. That is, as in the case of the legacy scheme, different terminals configure the uplink SDMA or MU-MIMO by the scheduling of the base station to allocate frequency resources of the same PUSCH, but improve the data throughput by maintaining the orthogonality of the uplink reference signal The transmission structure for the uplink reference signal and the PUSCH is modified as follows, and the overhead of the reference signal is reduced to increase the data throughput.

5 is a diagram illustrating an example of a PUSCH subframe structure according to multiple TTI (or subframe) scheduling in a normal CP according to an embodiment of the present invention.

510, 520, 530, and 540, data symbols and RS symbols are configured according to respective TTI or sub-frame scheduling.

6 is a diagram illustrating an example of a PUSCH subframe structure according to multiple TTI (or subframe) scheduling in an extended CP according to an embodiment of the present invention.

610, 620, 630, and 640, data symbols and RS symbols are configured according to respective TTI or sub-frame scheduling.

For single layer transmission, intra and inter-subframe frequency hopping between slots is applied depending on whether frequency hopping that can be instructed by the UL DCI is set in the structures of FIGS. 5 and 6 It is possible to assign the first slot and the second slot of each subframe to different frequency regions, and since resource allocation of the PUSCH is performed through one scheduling grant, the first subframe and the second subframe The frequency hopping pattern of the PUSCH of the frame is set to be the same. In this case, demodulation is performed based on the reference signal in the slot in which the demodulation reference signal exists in the same frequency region during the PUSCH demodulation for the transmission of the uplink PUSCH. 5, for example, it is possible to perform demodulation based on the demodulation reference signal in the slot 0 because the resource allocation area is the same in the frequency domain for the PUSCH in the slot 0 and the slot 2, So that demodulation is performed on the basis of the demodulation reference signal in slot 3, since the resource allocation area in the frequency domain with respect to the PUSCH of slot 3 is the same. Although FIG. 5 has been described with reference to FIG. 5, in a similar manner, 520, 530, and 540 of FIG. 5 also allow the PUSCH of the same resource allocation area to be demodulated based on a slot having a demodulation reference signal. 6, 620, 630, and 640 of FIG. 6 as in the case of the normal CP, demodulation of the PUSCH of the same resource allocation area is performed based on the slot having the demodulation reference signal . So that demodulation for PUSCH transmission is performed based on a demodulation reference signal existing in one subframe even in case of inter-frame frequency hopping.

Further, each of the following features can be obtained with respect to the structures of FIG. 5 and FIG. 5 and 6 illustrate a case where a channel is not changed significantly in a low mobility state, and then an accurate channel estimation is performed at a reference signal, and then interpolation (or interpolation) is performed for channel estimation in a data symbol having no reference signal. In this case, since the channel estimation value of the data channel is interpolated based on the accurate channel estimation at the position of the reference signal due to the channel having a small variation in the case, Reliability can be secured.

5 and 6, since the channels of the reference signals to which the OCC is allocated are most similar when the OCC-allocated reference signals used for transmission of multiple layers are estimated, Since the accuracy of the channel estimation can be increased, an error of the channel estimation value of the reference signal, for example, a mean square error value between the reference signal and the actual channel at the position can be measured to be low. Therefore, since the interpolation method and the extrapolation method (extrapolation method) for the data channel are performed with the corresponding channel estimation value, the reliability of the channel estimation for the data channel can be secured.

Referring to FIG. 5, reference numerals 530, 540, 630, and 640 in FIGS. 5 and 6 have the advantage that patterns of reference signals can be taken in the same subframe for each subframe, There is an advantage that a physical channel can be mapped based on one subframe that is not two subframe-based mappings to which a physical channel is mapped.

Hereinafter, embodiments of the present invention will be described with reference to a method for setting UE-specific so as to have different patterns so that different reference signal symbols between UEs can be allocated.

As a method of setting the pattern, there is a method of assigning four or two orthogonal patterns to each of the terminals. Among the four or two patterns, a method of setting a pattern used by the UE may be an explicit signaling method, for example, a method of directly instructing the corresponding pattern on the uplink DCI format, There may be a method of determining a corresponding pattern by using a code-point remaining on the DCI format as an implicit signaling (or implicit, implicit signaling) There may be a method of assigning a reference signal allocation pattern of a terminal to be dependent on a value indicated in a cyclic shift field and also a method of modulo 4 or modulo 4 according to C- or < RTI ID = 0.0 > 2). < / RTI > Alternatively, there may be a method of setting different reference signal symbols between UEs belonging to each cell so as to have different patterns so as to reduce the interference of the reference signal for the uplink for each cell . This will be a way to set different patterns based on the cell ID.

In the method of the present invention, the number of subframes used in the multi-TTI and multiple subframe scheduling is represented by two subframes in FIGS. 5 and 6 of the present invention. However, this method can be extended to multiple subframes have. That is, the embodiment of FIGS. 5 and 6 can be extended to transmit a reference signal while ensuring orthogonality among 2N (N is a natural number of 1 or more) subframes.

Hereinafter, a method of transmitting a downlink control signal in a small-cell environment and an apparatus thereof will be described.

In case of applying multiple TTI, multiple sub-frame scheduling or cross sub-frame scheduling to a small cell environment and an arbitrary cell / base station / RRH / antenna / RU, scheduling information for each sub- The way to be informed should be considered. Therefore, the present invention proposes a signaling method for informing the corresponding scheduling information as follows. The methods herein can be considered as a method that can be applied to both upward and downward directions.

- Directly directing relevant information as explicit signaling

This is a method of adding 1 bit indicating the execution of multiple TTI, multiple subframe scheduling, or cross subframe scheduling to DCI, which is a scheduling grant. For example, it is possible to perform multi-TTI or multi-sub-frame scheduling by including UL DCI format 0, DCI format 4, or new DCI format, which is an uplink scheduling grant, in transmission for an uplink. A 1-bit indicator indicating that multiple TTI, multiple subframe scheduling, or cross subframe scheduling is performed is added to the DCI format 1a / 1b / 1c / 1d / 2b / 2c / 2d in the downlink DCI format can do. A method of indicating that multiple sub-frame scheduling or cross sub-frame scheduling is performed using only a subset of some of the downlink DCI formats may be considered.

Alternatively, multiple RRC parameters may be set for multiple TTI, multiple sub-frame scheduling, or cross sub-frame scheduling, and multiple TTIs and multiple sub-frames may be multiplexed on the downlink and uplink DCI formats, It is possible to consider a method of determining whether 1-bit indicates that frame scheduling or cross sub-frame scheduling is performed.

Also, a method of indicating the number of subframes for multi-TTI (or subframe) scheduling can be considered, which is an embodiment indicating the number of subframes in multi-TTI (or subframe) scheduling. Alternatively, there may be a method of fixing the number of subframes used in each cell, and a method of indicating the number of subframes for multi-TTI (or subframe) scheduling with RRC in a semi-static manner Can be considered. Or a method of dynamically indicating the number of subframes to be scheduled through PDCCH / EPDCCH can be considered.

When the UE includes PDCCH or EPDCCH with multiple TTI, multiple sub-frame scheduling, or cross-subframe scheduling related indication information, the UE transmits the downlink and downlink control channels, that is, blind decoding of the PDCCH / EPDCCH, A procedure of a terminal for detecting a grant and an uplink grant will be described below.

PDCCH, or EPDCCH in a case of including multiple TTI, multiple sub-frame scheduling, or cross-subframe scheduling related indication information, and a method of indicating a predefined RRC parameter through RRC through a 1-bit dynamic indication included in a PDCCH or an EPDCCH When detecting the PDCCH / EPDCCH, the UE acquires DCI format 1a, which is a DL grant that contains downlink scheduling information for a corresponding UE in a UE dedicated search space rather than a common search space, And defines the operation of the terminal to search DCI format 0 and DCI format 4 which are UL grants containing link scheduling information. Therefore, after the Rel-12, the UE can set the UE to search for a grant including the downlink scheduling information and the uplink scheduling information in the dedicated UE search space at the time of performing the related operation.

- Implicitly (implicitly) directing related information as implicit signaling

In the case of performing PUSCH transmission in the uplink, when multi-subframe scheduling is performed, "intra and inter frequency hopping" or "inter-frequency hopping" for PUSCH transmission may be off. In the case of a single layer transmission using the uplink DCI format 0, since a frequency hopping flag is not needed, a multi-TTI, a multiple sub-frame scheduling or a cross sub- Frame scheduling is performed. Alternatively, it is possible to perform instructions for multiple TTI, multiple sub-frame scheduling, or cross sub-frame scheduling using a code-point remaining in the information used in the uplink DCI format 0 or 4. 1b / 1c / 1d / 2b / 2c / 2d as an implicit indication method for performing an instruction for multiple TTI, multiple subframe scheduling or cross subframe scheduling for downlink similarly to the uplink. A method of using the remaining code points among the information elements can be considered.

Meanwhile, as another embodiment of the implied embodiment, there may be a method of determining a reference signal allocation pattern of the terminal to depend on a value indicated in a cyclic shift field transmitted on a DCI format allocated to the terminal . For example, the value of the cyclic shift field is as follows, the reference signal allocation pattern can be applied according to the value, and the terminal checks the value of the cyclic shift field on the received DCI format, Can be applied. May be set as shown in Table 1 as an embodiment. It is assumed that the terminal and the base station have already shared the reference signal allocation patterns shown in Table 1 and the information of Table 1 has been previously shared by the terminal and the base station.

In addition, according to the C-RNTI of the terminal, the rest can be divided into 2N (N is a natural number) as module 4 or 2 as module 2. 2N, N is 2, and a reference signal is allocated to one subframe among four consecutive subframes, the C-RNTI is divided by 4, and if the remainder is 1, the first pattern is generated. If the remainder is 2 A second pattern, a third pattern if the remaining one is 3, and a fourth pattern when the remaining patterns are zero. It is assumed that the reference signal allocation scheme for each pattern is already shared by the base station and the terminal, as in the embodiment using the cyclic shift value.

One embodiment of the present invention described below relates to a method of transmitting an uplink control channel according to downlink transmission, and relates to a transmission method of UCI according to uplink multiple sub-frame scheduling.

When PUCCH transmission according to multiple sub-frame scheduling is required, the PUCCH resource can be set, the PUCCH transmission can be simultaneously transmitted with the PUSCH transmission, and UCI (uplink control information, e.g., ACK / NACK , CSI, and SR) may be configured to piggyback to the PUSCH that is scheduled for multiple subframes. Here, for the resource mapping on the PUSCH resource of the piggybacked UCI, the UCI is mapped as in the existing legacy structure having two reference signal symbols in one subframe.

In this case, since the PUCCH transmission is defined to be transmitted only to the primary cell, it is transmitted on the PUCCH to the macro cell / base station / RRH / antenna / RU considered as the primary cell, or if there is a PUSCH in the primary cell If there is no RRC setting for simultaneous transmission of PUCCH and PUSCH, the UCI is piggybacked to the PUSCH, and if the RRC setting for simultaneous transmission of PUCCH and PUSCH is allowed, the UCI is transmitted on the PUCCH, A method for obtaining diversity in a UCI transmission in a head cell, a small cell environment considered as a secondary cell, and a UCI reception at a base station in an arbitrary cell / base station / RRH / antenna / RU . That is, when the UCI transmission to the macro cell / base station / RRH / antenna / RU fails, it is possible to secure the reliability of UCI through UCI transmission to the small cell / base station / RRH / antenna / RU. The opposite is also true.

This is because the backhaul between macro and small cell does not depend on ideal backhaul or non-ideal backhaul and it is possible to guarantee reliability of UCI information transmission and reception between terminal and base station. / Data transmission rate for the downlink can be ensured.

One embodiment of the present invention relates to a PHICH resource allocation scheme for ACK / NACK transmission according to PUSCH transmission of multiple TTIs when multiple TTI (or subframe) scheduling of an uplink PUSCH is performed.

In the case where the transport block is configured for a plurality of subframes and the scheduling grant exists for a plurality of subframes, the lowest index of the PRB to which the PUSCH is allocated and the lowest index of the PRB to which the PUSCH is allocated The PHICH resource allocation and the multiplexing between the UEs are performed by a cyclic shift value of the DMRS field existing in the scheduling grant.

In the case where the transport block is configured for each subframe and the scheduling grant exists for each subframe, the lowest index of the PRB to which the PUSCH is allocated and the DMRS field of each scheduling grant The multiplexing of the PHICH resources and the terminals is performed by the cyclic shift value (n_DMRS)

In contrast, when one scheduling grant performs scheduling of all subframes to reduce the overhead of the control channel and the transport block is configured for each subframe, HARQ must be performed in units of transport blocks, so a new PHICH resource allocation method Needs to be considered.

The hopping of the cyclic shift for the DMRS is essentially applied to each slot, so that the cyclic shift value of the DMRS used in the first subframe indicated by the cyclic shift value (n_DMRS) of the DMRS field by the scheduling grant, The cyclic shift value of the DMRS used in the subframe is different. Therefore, the PHICH resource allocation is performed using the cyclic shift value of the DMRS actually used in the second subframe. This can be considered as a way to enable multiplexing of PHICH resources for two transport blocks transmitted in two subframes at a time.

The UE can control the flexibility of resource allocation with respect to the amount of data to be transmitted by the base station at the same time unit as the frequency unit so as to improve the UE experience according to the increase of data traffic . Also, it is possible to reduce the overhead of the downlink control channel PDCCH / EPDCCH for allocating a scheduling grant for enabling the UE to transmit the uplink PUSCH for each subframe. The overhead of the downlink control channel PDCCH can be reduced by reducing the allocation of the PHICH resources that can be generated according to the uplink PUSCH transmission that can be transmitted for each subframe.

In the case of applying multiple TTIs and multiple subframe scheduling to a small cell environment and an arbitrary cell / base station / RRH / antenna / RU, uplink PUSCH transmission using multi- An uplink reference signal applying an orthogonal cover code (OCC) having a length of 2 (length-2), a data transmission and reception process and a device implementing the same will be described in order to maintain orthogonality of a link reference signal. In the following description, the downlink channel includes a downlink control channel, and the downlink control channel includes a PDCCH or an EPDCCH.

FIG. 7 is a diagram illustrating a process of operating a terminal according to an embodiment of the present invention. Referring to FIG.

The operation of the terminal is as follows. First, the terminal receives a downlink channel including indication information necessary for transmitting a reference signal from a base station (S710). The terminal generates a reference signal according to the instruction information (S720). The UE then transmits the uplink channel by including the reference signal in any one of the 2N subframes. The N is a natural number equal to or greater than 1, and the indication information indicates whether multiple TTI or multiple subframe scheduling is explicitly performed Or implicitly (S730). In step S720, the UE can confirm the indication information included in the 1-bit DCI format. If a part of the indication information is included in the RRC parameter, Can confirm the number of sub-frames for multi-TTI or multiple sub-frame scheduling in the RRC parameter included in the downlink channel when the indication information is confirmed in the 1-bit. When the BS transmits the indication information in the implied indication mode, the UE can confirm the indication information in the frequency hopping flag when the frequency hopping in the uplink channel is inactivated. In another embodiment, It is possible to confirm the instruction information. Also, as shown in Table 1, the UE can confirm the C-RNTI with the indication information included in the cyclic shift field on the DCI format and use the value calculated by performing the modulo operation on the C-RNTI of the UE with the 2N And can be confirmed by the instruction information.

When a PHICH resource is allocated in the uplink channel transmission in step S730, if the UE is in the scheduling grant of all the subframes and the transport block is configured in units of subframes, the cyclic shift value of the DMRS used in the 2N consecutive subframes The reference signal can be generated and transmitted.

FIG. 8 is a flowchart illustrating a process of a base station according to an embodiment of the present invention. Referring to FIG. The process of base station operation is divided into three stages. The base station generates a downlink channel including indication information necessary for transmission of a reference signal (S810). Then, the generated downlink channel is transmitted to the UE in step S820, and then, in the uplink channel transmitted from the UE, a signal of a subframe in which a reference signal is not included is used by using a reference signal of a subframe including a reference signal (S830). Herein, the UE transmits an uplink channel by including a reference signal in any one of 2N subframes, where N is a natural number equal to or greater than 1, and the indication information indicates whether multiple TTI or multiple subframe scheduling is explicit Or implicitly.

More specifically, in step 810, the BS may include the indication information in 1 bit of the DCI format when generating the downlink channel. In order to further include a part of the indication information in the RRC parameter, 1 bit of indication information and include an RRC parameter indicating the number of subframes for scheduling multiple TTIs or multiple subframes in the downlink channel. When the BS transmits indication information in an implicit indication mode, the BS may include the indication information in a frequency hopping flag when the frequency hopping in the uplink channel is deactivated. In another embodiment, The instruction information may be included in the remaining code points. Also, as shown in Table 1, the base station can set the cyclic shift value corresponding to the instruction information to the cyclic shift field in the DCI format, and perform the modulo operation on the C-RNTI of the UE with the 2N As a result, the C-RNTI value can be set such that the instruction information is indicated.

When the uplink channel is a scheduling grant of all subframes, if a transmission block is configured in units of subframes, the cyclic-shift value of the DMRS used in the 2N consecutive subframes This can be different.

In addition, in the demodulation of the subframe, the BS may use a reference signal included in an adjacent subframe to demodulate the subframe in which the reference signal is not included, as described in the embodiments of FIGS.

9 is a diagram illustrating a configuration of a user terminal according to another embodiment of the present invention.

9, a user terminal 900 according to another embodiment includes a receiving unit 930, a control unit 910, and a transmitting unit 920.

The receiving unit 930 receives downlink control information, data, and a message from the base station through the corresponding channel.

In addition, when the multi-TTI and multi-subframe scheduling necessary for carrying out the present invention are applied to a small cell environment and an arbitrary cell / base station / RRH / antenna / RU, the controller 910 may multiplex Layer PUSCH, the orthogonal cover code (OCC) having a length of 2 (length-2) is applied to maintain the orthogonality of the uplink reference signals between the antennas and the layers. .

The transmitter 920 transmits uplink control information, data, and a message to the base station through the corresponding channel.

A detailed implementation of the user terminal, i.e., the terminal, will be described below. The receiver 930 receives a downlink channel including indication information necessary for transmitting a reference signal from the base station, and the controller 910 generates a reference signal according to the indication information. In addition, the transmitter 920 transmits the uplink channel by including the reference signal in any one of 2N subframes, where N is a natural number equal to or greater than 1, and the indication information includes multiple TTIs or multiple subframe scheduling Or explicitly or implicitly.

When generating the reference signal, the control unit 910 can confirm the indication information included in 1 bit of the DCI format. More specifically, when the indication information is confirmed in the 1-bit, the controller 910 detects the RRC parameter included in the downlink channel The number of subframes for multiple TTI or multiple subframe scheduling can be confirmed.

Also, in the embodiment in which the directive information is transmitted implicitly, the controller 910 can confirm the indication information in the frequency hopping flag when the frequency hopping in the uplink channel is inactivated. Also, in another embodiment where the indication information is implicitly transmitted, the indication information may be included in the remaining code points of the DCI format, or included in the cyclic shift field on the DCI format, or may be included in the C- Can be included in the value calculated by performing the operation with 2N.

Meanwhile, when the transmission block is configured in units of subframes in the state of being a scheduling grant of all subframes, the controller 910 generates a reference signal such that the cyclic shift value of the DMRS used in the 2N consecutive subframes is different .

10 is a diagram illustrating a configuration of a base station according to another embodiment of the present invention.

Referring to FIG. 10, a base station 1000 according to another embodiment includes a control unit 1010, a transmission unit 1020, and a reception unit 1030.

In a case where the multi-TTI and multi-subframe scheduling necessary for carrying out the present invention described above are applied to a small cell environment and an arbitrary cell / base station / RRH / antenna / RU, the controller 1010 controls the multi- The orthogonal cover code (OCC) having a length of 2 (length 2) is applied to maintain the orthogonality of the uplink reference signals between the antennas and the layers. .

The transmitting unit 1020 and the receiving unit 1030 are used to transmit and receive signals, messages, and data necessary for carrying out the present invention to and from the terminal.

The detailed implementation of the base station is as follows. The controller 1010 generates a downlink channel including indication information required for transmission of a reference signal, and the transmitter 1020 transmits the generated downlink channel to the terminal. Here, after receiving the downlink channel, the UE transmits an uplink channel by including a reference signal in any one of 2N subframes. Where N is a natural number greater than or equal to 1 and the indication information may indicate explicitly or implicitly multiple TTI or multiple subframe scheduling.

More specifically, the controller 1010 may include the indication information in 1 bit of the DCI format for explicit signaling, and may also include 1-bit indication information in the DCI, and may perform multiple TTI or multiple subframe scheduling RRC < / RTI > For implicit signaling, the control unit 1010 may include the indication information in a frequency hopping flag when the frequency hopping in the uplink channel is inactivated. Also, the controller 1010 may include the instruction information in the remaining code points of the DCI format, or include the instruction information in the cyclic shift field on the DCI format, or perform the modulo operation on the C-RNTI of the terminal by the 2N Can be included in the calculated value. When the uplink channel is a scheduling grant of all subframes in association with the PHICH resource allocation of the UE, if the transmission blocks are configured in units of subframes, the cyclic shift value of the DMRS used in the 2N consecutive subframes is different And may instruct the controller 1010 to set a different cyclic shift value of the DMRS when generating a downlink channel. Also, after receiving the uplink channel transmitted by the user equipment, the receiver 1030 uses the reference signal of the subframe including the reference signal in the received uplink channel, so that the reference signal is not included in the received uplink channel It is possible to demodulate the signal of the sub-frame.

In the case of applying multi-TTI and multi-subframe scheduling to a small cell environment or an arbitrary cell / base station / RRH / antenna / RU, the present invention as described above can be applied to an uplink PUSCH transmission using multi- And an orthogonal cover code (OCC) having a length of 2 to maintain the orthogonality of the uplink reference signal between the antenna and the layers.

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 scope of protection of the present invention should be construed according to the following claims, and all technical ideas falling within the scope of the same shall be construed as falling within the scope of the present invention.

Claims (24)

A method for a terminal to transmit an uplink reference signal,
Receiving a downlink channel including indication information necessary for transmitting a reference signal from a base station;
Generating a reference signal according to the instruction information; And
And transmitting the uplink channel by including the reference signal in any one of 2N consecutive subframes,
Wherein the N is a natural number equal to or greater than 1 and the indication information indicates multiple TTI (Transmission Time Interval) or multiple subframe scheduling explicitly or implicitly.
The method according to claim 1,
Identifying the indication information included in one bit of the DCI format.
3. The method of claim 2,
And checking the number of sub-frames for multi-TTI or multi-sub-frame scheduling in an RRC (Radio Resource Control) parameter included in the downlink channel if the 1-bit indication information is confirmed.
The method according to claim 1,
Further comprising checking the indication information in a frequency hopping flag when frequency hopping in the uplink channel is deactivated.
The method according to claim 1,
RTI ID = 0.0 > DCI < / RTI > format.
The method according to claim 1,
Further comprising: performing a modulo operation on the C-RNTI of the UE using the 2N and verifying the C-RNTI with the indication information using the calculated value.
A method for a base station to receive an uplink reference signal,
Generating a downlink channel including an indication information required for a reference signal transmission; And
And transmitting the generated downlink channel to the terminal,
The UE transmits an uplink channel by including a reference signal in one of 2N consecutive subframes, where N is a natural number equal to or greater than 1, and the indication information includes a transmission time interval (TTI) Wherein the scheduling is instructed explicitly or implicitly.
8. The method of claim 7,
Wherein the generating step comprises the step of including the instruction information in one bit of the DCI format.
9. The method of claim 8,
Further comprising the step of including one bit of indication information in the DCI and including a Radio Resource Control (RRC) parameter indicating a number of subframes for scheduling multiple TTIs or multiple subframes in the downlink channel.
8. The method of claim 7,
Wherein the step of generating includes the step of including the indication information in a frequency hopping flag when frequency hopping in the uplink channel is inactivated.
8. The method of claim 7,
Wherein the step of generating comprises setting a cyclic shift value corresponding to the instruction information as a cyclic shift field in a DCI format.
8. The method of claim 7,
Wherein the generating comprises setting a C-RNTI value such that the indicator information is indicated as a result of 2N performing the modulo operation on the C-RNTI of the terminal.
8. The method of claim 7,
Wherein the base station further comprises demodulating a signal of a subframe that does not include a reference signal using a reference signal of a subframe including a reference signal in the transmitted uplink channel.
A receiving unit for receiving a downlink channel including indication information necessary for transmitting a reference signal from a base station;
A control unit for generating a reference signal according to the instruction information; And
And a transmitter for transmitting an uplink channel by including a reference signal in any one of 2N subframes,
Wherein the N is a natural number equal to or greater than 1, and the indication information indicates a transmission time interval (TTI) or multiple sub-frame scheduling explicitly or implicitly.
15. The method of claim 14,
Wherein the control unit confirms the instruction information included in one bit of the DCI format when generating the reference signal.
16. The method of claim 15,
Wherein the control unit checks the number of sub-frames for multi-TTI or multiple sub-frame scheduling in an RRC (Radio Resource Control) parameter included in the downlink channel when the 1-bit indication information is confirmed.
15. The method of claim 14,
Wherein the control unit checks the indication information in a frequency hopping flag when the frequency hopping in the uplink channel is inactivated.
15. The method of claim 14,
Wherein the indication information is included in a cyclic shift field on the DCI format or included in a value calculated by performing a modulo operation on the C-RNTI of the terminal by the 2N.
A control unit for generating a downlink channel including indication information necessary for reference signal transmission; And
And a transmitter for transmitting the generated downlink channel to the terminal,
The UE transmits an uplink channel by including a reference signal in one of 2N consecutive subframes, where N is a natural number equal to or greater than 1, and the indication information includes a transmission time interval (TTI) Wherein the scheduling is explicitly or implicitly instructed.
20. The method of claim 19,
Wherein the control unit includes the instruction information in one bit of the DCI format.
21. The method of claim 20,
Wherein the control unit includes a 1-bit indication information in the DCI and includes an RRC (Radio Resource Control) parameter indicating a number of subframes for scheduling multiple TTIs or multiple subframes in the downlink channel.
20. The method of claim 19,
Wherein the control unit includes the indication information in a frequency hopping flag when the frequency hopping in the uplink channel is inactivated.
20. The method of claim 19,
Wherein the controller includes the cyclic shift field on the DCI format or includes the C-RNTI of the UE in a value calculated by performing the modulo operation on the 2N.
20. The method of claim 19,
The receiver receives the uplink channel transmitted by the terminal,
Wherein the control unit demodulates a signal of a subframe in which the reference signal is not included, using the reference signal of the subframe including the reference signal in the received uplink channel.

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