JP5999849B2 - Terminal apparatus, base station apparatus, communication system, and communication method - Google Patents

Description

  The present invention relates to a terminal device, a base station device, a communication system, and a communication method.

  3CDMA (Third Generation Partnership Project) WCDMA (Wideband Code Divide Multiple Access), LTE (Long Term Evolution), LTE-A (LTE-Advanced) By adopting a cellular configuration in which a plurality of areas covered by a base station device (base station, transmission station, downlink transmission device, uplink reception device, eNodeB) or a transmission station according to the base station are arranged in a cell (Cell) shape, The communication area can be expanded.

  In addition, by using different frequencies between adjacent cells or sectors, a terminal device (mobile station, receiving station, uplink transmitter, downlink receiver, mobile terminal, cell edge (cell edge) region or sector edge region, Although UE (User Equipment) can also perform communication without receiving interference of transmission signals from a plurality of base stations, there is a problem that frequency utilization efficiency is low. On the other hand, frequency utilization efficiency can be improved by using the same frequency between adjacent cells or sectors, but it is necessary to take measures against interference with terminal devices in the cell edge region.

  Also, depending on the transmission path conditions between the base station and the terminal device, the modulation scheme and coding rate (MCS), spatial multiplexing number (number of layers, rank), precoder (precoder), etc. are applied. More efficient data transmission can be realized by controlling the operation. Non-Patent Document 1 shows a method of performing these controls.

  FIG. 13 is a diagram illustrating a base station 1301 and a terminal device 1302 in LTE. In LTE, when adaptively controlling the MCS, the spatial multiplexing number, and the precoder for the downlink transmission downlink transmission signal 1303 to be transmitted, the terminal device 1302 transmits the downlink transmission downlink transmission signal transmitted from the base station 1301. Referring to a downlink reference signal (RS) included in 1303, a rank index RI (Rank Indicator) for designating a suitable spatial multiplexing number and precoding matrix information PMI (Precoding Matrix Indicator) for designating a suitable precoder ) Receive quality information typified by a channel quality indicator CQI (Channel Quality Indicator) or the like for specifying a suitable transmission rate is calculated, and the base station 13 is connected via the uplink channel 1304. To report to the 1.

3rd Generation Partnership Project; Technical Specification Group Radio Access Network; Evolved Universal Terrestrial Radio Access (E-UTRA); Physical layer procedures (Release 8), 12 May 2008, 3GPP TS36.213 V8.8.0 (2009-9)

  However, in the conventional communication method, when the reception quality information that is the control information is transmitted using the data transmission channel, the processing for the reception quality information is unambiguous regardless of the situation. It was a hindrance.

  The present invention has been made in view of the above problems, and an object thereof is to efficiently report reception quality information when transmitting reception quality information, which is control information, using a data transmission channel. It is an object to provide a terminal device, a base station device, a communication system, and a communication method.

  (1) The present invention has been made to solve the above-described problem, and is a communication system including a terminal device that communicates with a base station device, wherein the terminal device includes at least one suitable precoder from a plurality of precoders. When the partial precoder information for designating the partial precoder information together with the data is transmitted to the base station apparatus, if the partial precoder information is a non-periodically reported partial precoder information, the partial precoder information is transmitted in the same manner as the data When the partial precoder information is rearranged and the partial precoder information is periodically reported, the partial precoder information is rearranged by a method different from that of the data. Information is transmitted to the base station apparatus, and the base station apparatus transmits the partial pre-coding transmitted from the mobile station. It receives the header information, and acquires the partial precoder information by the same sort or the data with different sorting sorting process as Undo and the data.

  (2) Also, in one aspect of the present invention, a partial precoder for designating at least one suitable precoder from a plurality of precoders transmitted from the terminal device, the base station device communicating with the terminal device When receiving the information and data, if the partial precoder information is the partial precoder information reported aperiodically, the partial precoder information is rearranged in the same manner as the data, and the partial precoder information If the information is a partial precoder information that is periodically reported, the partial precoder information is rearranged by a method different from the data, and based on the same rearrangement as the data or a different rearrangement from the data. The partial precoder information is obtained by rearrangement processing such as returning.

  (3) Moreover, in one aspect of the present invention, there is provided a processing method in a base station device that communicates with a terminal device, in order to designate at least one suitable precoder from a plurality of precoders transmitted by the terminal device. When receiving the partial precoder information and the data, if the partial precoder information is the partial precoder information reported aperiodically, the partial precoder information is rearranged in the same manner as the data, When the partial precoder information is periodically reported partial precoder information, the partial precoder information is rearranged by a method different from that of the data, and the base station apparatus performs the same rearrangement or The partial precoder information is acquired by a rearrangement process that restores the rearrangement different from the data. The features.

(4) In addition, in one aspect of the present invention, a terminal apparatus that communicates with a base station apparatus, the base station apparatus includes partial precoder information for designating at least one suitable precoder from a plurality of precoders together with data. When the partial precoder information is a non-periodically reported partial precoder information, the partial precoder information is rearranged in the same manner as the data,
If the partial precoder information is periodically reported partial precoder information, the partial precoder information is rearranged by a method different from the data,
It is characterized by that.

  (5) According to another aspect of the present invention, there is provided a processing method in a terminal device that communicates with a base station device, wherein the terminal device designates at least one suitable precoder from a plurality of precoders. When transmitting information together with data to the base station apparatus, if the partial precoder information is partial precoder information reported aperiodically, the terminal apparatus arranges the partial precoder information in the same manner as the data. When the partial precoder information is periodically reported, the terminal device rearranges the partial precoder information by a method different from the data.

  According to the present invention, when reception quality information, which is control information, is transmitted using a data transmission channel, it is possible to efficiently report reception quality information.

It is a schematic block diagram which shows the structure of the communication system which concerns on the 1st Embodiment of this invention. FIG. 3 is a diagram illustrating an example of a downlink radio frame configuration in the embodiment. FIG. 3 is a diagram illustrating an example of an uplink radio frame configuration in the embodiment. It is a figure which shows an example of the block configuration of the base station apparatus in the embodiment. It is a figure which shows an example of the block configuration of the terminal device in the embodiment. It is a figure which shows an example of the procedure in the aperiodic feedback mode in the same embodiment. It is a figure which shows an example of the mapping in the aperiodic feedback mode in the embodiment. It is a figure which shows an example of the procedure in the periodic feedback mode in the embodiment. It is a figure which shows another example of the procedure in the periodic feedback mode in the same embodiment. It is a figure which shows another example of the procedure in the periodic feedback mode in the same embodiment. It is a figure which shows an example of the procedure in the uplink data transmission in the embodiment. It is a figure which shows an example of the mapping at the time of the piggyback of the periodic feedback mode in the embodiment. It is a schematic block diagram which shows the structure of a communication system.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic configuration diagram showing a configuration of a communication system according to the first embodiment of the present invention. The communication system of the figure assumes an LTE-A system, and a base station device (base station, transmission station, downlink transmission device, uplink reception device, eNodeB) 101 and a terminal device (mobile station, A receiving station, an uplink transmitting device, a downlink receiving device, a mobile terminal, and a UE (User Equipment) 102. An MCS (Modulatio) for the downlink transmission signal 103 transmitted in Cell # 0 and Cell # 1.
When adaptively controlling transmission parameters such as n and Coding Scheme), rank, and precoder, the terminal apparatus 102 receives a downlink reference signal (RS) included in the downlink transmission signal 103 transmitted from the base station 101. , A rank index RI (Rank Indicator) for designating a suitable spatial multiplexing number, a plurality of partial precoder information PI (Precoder Information) for designating a suitable Precoder, and a suitable transmission rate (modulation method) The reception quality information such as a channel quality index CQI (Channel Quality Indicator) that specifies a coding rate, a transport block length, etc.) is calculated, and an uplink channel is calculated. Through 104, it is reported to the base station 101. Here, a case where partial precoder information 1 (PI1, first partial precoder information) and partial precoder information 2 (PI2, second partial precoder information) are reported as partial precoder information PI will be described. For example, a suitable precoder W (i, j) is designated by using an index i that can be represented by m bits as PI1 and an index j that can be represented by n bits as PI2. Alternatively, a suitable precoder W (r) (i, j) is designated using rank r. However, W (i, j) is a matrix uniquely determined by i and j, and this determination method (codebook) is shared between the base station apparatus and the terminal apparatus. In other words, a codebook is a plurality of suitable precoder candidates. Further, as a preferable precoder calculation method, for example, a method of calculating a precoder that increases the downlink received signal power in consideration of the downlink propagation path can be used.

  FIG. 2 shows an example of a downlink radio frame configuration according to the present embodiment. An OFDM (Orthogonal Frequency Division Multiplex) access scheme is used for the downlink. In the downlink, a physical downlink control channel (PDCCH; Physical Downlink Control Channel), a physical downlink shared channel (PDSCH; Physical Downlink Shared Channel), and the like are allocated. Also, a downlink reference signal (RS; Reference Signal) is multiplexed on a part of the PDSCH. The downlink radio frame is composed of a downlink resource block (RB) pair. This downlink RB pair is a unit such as downlink radio resource allocation, and is based on a predetermined frequency band (RB bandwidth) and time band (2 slots = 1 subframe). Become. One downlink RB pair is composed of two downlink RBs (RB bandwidth × slot) that are continuous in the time domain. One downlink RB is composed of 12 subcarriers in the frequency domain, and is composed of 7 OFDM symbols in the time domain. The physical downlink control channel is a physical channel through which downlink control information such as a terminal device identifier, downlink shared channel scheduling information, uplink shared channel scheduling information, modulation scheme, coding rate, and retransmission parameter is transmitted. . In addition, although the downlink sub-frame in one CC is described here, a downlink sub-frame is prescribed | regulated for every CC, and a downlink sub-frame is substantially synchronized between CC.

FIG. 3 shows an example of an uplink radio frame configuration according to the present embodiment. For the uplink, an SC-FDMA (Single Carrier-Frequency Division Multiple Access) system is used. In the uplink, a physical uplink shared channel (Physical Uplink Channel; PUSCH), a physical uplink control channel (Physical Uplink Control Channel; PUCCH), and the like are allocated. Further, an uplink reference signal is assigned to a part of PUSCH or PUCCH. The uplink radio frame is composed of uplink RB pairs. The uplink RB pair is a unit such as uplink radio resource allocation, and has a predetermined frequency band (RB
Bandwidth) and time zone (2 slots = 1 subframe). One uplink RB pair is composed of two uplink RBs (RB bandwidth × slot) that are continuous in the time domain. One uplink RB is composed of 12 subcarriers in the frequency domain, and is composed of 7 SC-FDMA symbols in the time domain.

  FIG. 4 is a schematic diagram illustrating an example of a block configuration of the base station apparatus according to the present embodiment. The base station apparatus includes a downlink subframe generation unit 401, an OFDM signal transmission unit 404, a transmission antenna (base station transmission antenna) 405, a reception antenna (base station reception antenna) 406, an SC-FDMA signal reception unit 407, and a filter unit 408. A code word processing unit 412 and an upper layer 413. The downlink subframe generation unit 401 includes a physical downlink control channel generation unit 402 and a downlink reference signal generation unit 403. The filter unit 408 has a feedback information extraction unit 409.

  FIG. 5 is a schematic diagram illustrating an example of a block configuration of the terminal device according to the present embodiment. The terminal apparatus includes a reception antenna (terminal reception antenna) 501, an OFDM signal reception unit 502, a downlink subframe processing unit 503, an upper layer 506, a feedback information generation unit 507, a codeword generation unit 508, and an uplink subframe generation unit 509. , SC-FDMA signal transmission unit 511 and transmission antenna (terminal transmission antenna) 512. The downlink subframe processing unit 503 includes a downlink reference signal extraction unit 504 and a physical downlink control channel extraction unit 505. The uplink subframe generation unit 509 includes an uplink reference signal generation unit 510.

  First, the flow of downlink transmission / reception will be described using FIG. 4 and FIG. In the base station apparatus, transmission data (also referred to as a transport block) for each codeword (transmission data sequence in the physical layer) sent from the higher layer 413 is error-correction-coded in the downlink subframe generation unit 401. The signal is converted into a modulation symbol sequence by modulation processing such as rate matching processing, PSK (Phase Shift Keying) modulation, or QAM (Quadrature Amplitude Modulation) modulation. The modulation symbol sequence is mapped to a resource element (RE; Resource element) which is a mapping unit of the modulation symbol sequence, and precoding processing is performed by a precoder instructed by an upper layer. Note that the RE in the downlink is defined corresponding to each subcarrier on each OFDM symbol. At this time, the transmission data sequence transmitted from the upper layer 413 includes control data for RRC (Radio Resource Control) signaling. Also, the physical downlink control channel generation unit 402 generates a physical downlink control channel according to an instruction from the higher layer 413. Here, the control information included in the physical downlink control channel includes information such as downlink transmission parameters, uplink resource allocation, uplink transmission parameters, and CQI request. The downlink reference signal generation unit 403 generates a downlink reference signal DLRS (Down Link Reference Signal). The downlink subframe generation unit 401 maps the physical downlink control channel and DLRS to the RE in the downlink subframe. The downlink subframe generated by the downlink subframe generation unit 401 is modulated into an OFDM signal by the OFDM signal transmission unit 404 and transmitted via the transmission antenna 405.

In the terminal device, the OFDM signal is received by the OFDM signal receiver 502 via the receiving antenna 501 and subjected to OFDM demodulation processing. The downlink subframe processing unit 503 extracts received data from the received downlink subframe and sends it to the upper layer 506. More specifically, modulation processing, rate matching processing, demodulation processing corresponding to error correction coding, rate matching processing, error correction decoding, and the like are performed in the downlink subframe generation unit 401. The downlink reference signal extraction unit 504 includes a downlink reference signal generation unit 403.
The DLRS generated in step DL and mapped in the downlink subframe generation unit 401 is extracted and sent to the feedback information generation unit 507. The physical downlink control channel extraction unit 505 extracts control information generated in the physical downlink control channel generation unit 402 and included in the physical downlink control channel mapped in the downlink subframe generation unit 401, and performs higher layer 506. Send to.

  Here, processing in downlink subframe generation section 401, OFDM signal transmission section 404 and transmission antenna 405 in the base station apparatus, and reception antenna 501, OFDM signal reception section 502 and downlink subframe processing section 503 in the terminal apparatus, The process in is performed for each downlink cell (CC). Moreover, the feedback information generation unit 507 generates reception quality information (feedback information) in a plurality of downlink cells.

  Next, the flow of uplink transmission / reception will be described using FIG. 4 and FIG. In the terminal device, transmission data (also referred to as a transport block) for each codeword transmitted from the upper layer 506 is processed by the codeword generation unit 508 by processing such as error correction coding and rate matching processing. Converted to (Code Word). The feedback information generation unit 507 generates feedback information by encoding RI, PI1, PI2, CQI, and the like using the DLRS extracted by the downlink reference signal extraction unit 507 in accordance with an instruction from the higher layer 506. The uplink reference signal generation unit 510 generates an uplink reference signal ULRS (UpLink Reference Signal). The uplink subframe generation unit 509 rearranges the codeword modulation symbol sequence and the feedback information by a predetermined method, and then maps the codeword modulation symbol sequence and the feedback information together with the uplink reference signal to the uplink subframe. The SC-FDMA signal transmission unit 511 performs SC-FDMA modulation on the uplink subframe to generate an SC-FDMA signal, and transmits the SC-FDMA signal via the transmission antenna 512.

  In the base station apparatus, an SC-FDMA signal is received by the SC-FDMA signal receiving unit 407 via the receiving antenna 406, and SC-FDMA demodulation processing is performed. The filter unit 503 extracts a codeword from the received uplink subframe and sends it to the codeword processing unit 412. The code word processing unit extracts received data from the code word and sends it to the upper layer 413. More specifically, the received data is extracted by performing rate matching processing in the codeword generation unit 508, rate matching processing corresponding to error correction coding, error correction decoding, and the like. The feedback information extraction unit 409 in the filter unit 408 extracts and decodes the feedback information generated in the feedback information generation unit 507 and mapped in the uplink subframe generation unit 401 in accordance with an instruction from the upper layer, To 413. Here, in the filtering process performed by the filter unit 503, a method such as ZF (Zero Forcing), MMSE (Minimum Mean Square Error), or MLD (Maximum Likelihood Detection) is used for the received signal for each receiving antenna 406. The signal for each codeword is detected.

FIG. 6 shows an example of a procedure according to the present embodiment. The procedure shown in FIG. 6 is an example of a procedure in an aperiodic feedback mode (first feedback mode) in which RI, PI1, PI2, and W-CQI are fed back aperiodically. First, the base station sets a feedback parameter in the terminal device via RRC signaling (step S601). Next, the base station notifies the terminal device of a CQI request that is information for instructing aperiodic feedback (step S602). Also, a resource (for example, a physical uplink shared channel) that reports feedback information at the same time is allocated. The terminal device instructed for aperiodic feedback reports RI, PI1, PI2, and W-CQI simultaneously (at the same timing) to the base station device according to the set feedback parameters (step S603). In the case of the aperiodic feedback mode in which the S-CQI is fed back, the S-CQI is also reported at the same time. Here, the terminal apparatus reports S-CQIs of a plurality of bands BP at the same time. Although an example in which notification of a CQI request in the terminal device in step S602 is performed by dynamic signaling via a physical downlink control channel will be described here, the present invention is not limited to this. For example, the same effect can be obtained even when an aperiodic feedback instruction is given by quasi-static signaling via RRC signaling. In this case, it is preferable to specify a subframe to be further reported.

  Next, feedback information mapping in the aperiodic feedback mode will be described. FIG. 7 shows an example of feedback information mapping. The rearrangement and mapping shown in FIG. 7 are examples in the case of transmitting a plurality of CWs (CW0 and CW1) in the uplink. Here, it is assumed that CW0 and CW1 are transmitted using layer 1 and layer 2, respectively. Here, the layer (layer) is a spatial multiplexing index, and the number of layers indicates the spatial multiplexing number. ULRS is mapped to the 4th and 11th SC-FDMA symbols of each layer. Feedback information including RI and other feedback information (for example, W-CQI, PI1, and PI2) are rearranged as shown in FIG. The parameters here are only examples, and other parameters can be used as a matter of course. For example, when only CW0 is transmitted, the same mapping as that of layer 1 in FIG. 7 may be performed.

  More specifically, CQI, PI1, and PI2 are first combined with CW0. At this time, the feedback information including CQI and PI2 is combined in the order of CW0. After that, the combined symbol sequence is the forefront of the first SC-FDMA symbol of layer 1, the forefront of the second SC-FDMA symbol of layer 1,... Mapping in order from the forefront of each SC-FDMA symbol of the layer transmitting CW0, such as the forefront of the first SC-FDMA symbol, the second from the front of the first SC-FDMA symbol of layer 1, and so on. Sorting is performed as shown. On the other hand, CW1 is the forefront of the first SC-FDMA symbol of layer 2, the forefront of the second SC-FDMA symbol of layer 2,... For example, the forefront of the FDMA symbol, the second from the front of the first SC-FDMA symbol of layer 2, and so on are mapped sequentially from the forefront of each SC-FDMA symbol of the layer transmitting CW1. Sorting is done. RI is part or all of SC-FDMA symbols near ULRS in all layers (for example, after the second, sixth, ninth, and thirteenth SC-FDMA symbols in layers 1 and 2 as shown in FIG. 7). Rearrangement is performed to be mapped. That is, RI and CQI / PI1 / PI2 are transmitted (reported) by different spatial multiplexing numbers or independent spatial multiplexing methods / mapping methods.

  These rearrangement and mapping processes are performed by the uplink subframe generation unit 509 under the instruction of the higher layer 506. On the other hand, the feedback information extraction unit 409 in the base station apparatus uses the demapping corresponding to the mapping in the uplink subframe generation unit 509 and the rearrangement in the uplink subframe generation unit 509 based on the instruction of the higher layer 413. The feedback information is acquired by performing the rearrangement process to return to step (b).

  Here, a code book used for calculating PI1 and PI2 will be described. As described above, a suitable precoder W (i, j) is designated by using an index i that can be represented by m bits as PI1 and an index j that can be represented by n bits as PI2. A code book defines the maximum 2m + n types of W (i, j). In the aperiodic feedback mode, feedback with a high degree of freedom is possible by increasing the degree of freedom in selecting W (i, j) in the codebook.

  FIG. 8 shows an example of a procedure in the periodic feedback mode according to the present embodiment. The procedure shown in FIG. 8 is an example of a procedure in a periodic feedback mode (second feedback mode) in which RI, PI1, PI2, and W-CQI (Wideband CQI) in one cell are periodically fed back. Note that W-CQI is one CQI that represents the system bandwidth (component carrier bandwidth). Further, the feedback mode here is a setting of a combination of contents of reception quality information fed back from the terminal apparatus to the base station apparatus, a measurement or generation method of each content, a feedback method of each content or a resource used for feedback including. First, the base station sets a feedback parameter in the terminal device via RRC signaling and instructs the second feedback mode (step S801). The terminal device instructed to perform periodic feedback performs physical uplink control of RI and PI1 (step S802), PI2 and W-CQI (step S803) to the base station device periodically according to the set feedback parameters. Report over the channel. Here, the report in step S802 is referred to as feedback type 1A, and the report in step S803 is referred to as feedback type 1B.

  FIG. 9 shows another example of the procedure in the periodic feedback mode according to the present embodiment. The procedure shown in FIG. 9 is a periodic feedback mode (third mode) in which RI, PTI (Precoder Type Indication), PI1, PI2, W-CQI, and S-CQI (Subband-CQI) in one cell are periodically fed back. This is an example of a procedure in the feedback mode). In the feedback mode in which S-CQI (Subband-CQI) is periodically fed back, S-CQI is further periodically reported. Here, the S-CQI is a CQI that divides a system bandwidth (component carrier bandwidth) into a plurality of narrow bands and represents a divided band BP (Bandwidth Part). More specifically, the CQI in one subband of one or more subbands (bands obtained by further dividing BP) included in the BP. As will be described later, the PTI is an index for switching the content to be fed back. First, the base station sets a feedback parameter in the terminal device via RRC signaling and instructs a third feedback mode (step S901). The terminal apparatus instructed to perform periodic feedback periodically reports RI and PTI (step S902) to the base station apparatus via the physical uplink control channel according to the set feedback parameters. When the PTI reported in step 902 indicates a precoder type that reports PI2 for each subband, PI1 and W-CQI (step S903) and PI2 and S-CQI (step S903) are set according to the set feedback parameters. Are periodically reported to the base station apparatus via the physical uplink control channel. Here, PI2 is PI2 calculated in the subband corresponding to S-CQI transmitted simultaneously. On the other hand, when the PTI reported in step 902 indicates a precoder type that reports PI2 in the system bandwidth (component carrier bandwidth), PI2 and W-CQI (step S905) and S are set according to the set feedback parameters. -CQI (step S906) is periodically reported to the base station apparatus via the physical uplink control channel. In this case, PI1 is not reported, and a codebook that designates a suitable precoder only by PI2 is used. Here, the report of step S902 is called feedback type 2A, the report of step S903 is called feedback type 2B, the report of step S904 is called feedback type 2C, the report of step S905 is called feedback type 2D, and the report of step S906 is called feedback type 2E. The feedback type 2D may be the same report as the feedback type 1B, and the calculation method of PI2 and W-CQI can be set individually.

FIG. 10 shows another example of the procedure in the periodic feedback mode according to the present embodiment. The procedure shown in FIG. 10 is an example of a procedure in a periodic feedback mode (fourth feedback mode) in which RI, PI1, PI2, W-CQI, and S-CQI in one cell are periodically fed back. First, the base station sets a feedback parameter in the terminal device via RRC signaling and instructs a fourth feedback mode (step S1001). The terminal apparatus instructed to perform periodic feedback periodically reports RI (step S1002) to the base station apparatus via the physical uplink control channel according to the set feedback parameter. Next, PI1 and PI2 and W-CQI (step S1003) and S-CQI (step S1003) are periodically reported to the base station apparatus via the physical uplink control channel according to the set feedback parameters. Here, the report of step S1002 is referred to as feedback type 3A, the report of step S1003 is referred to as feedback type 3B, and the report of step S1004 is referred to as feedback type 3C. Note that the feedback type 3C may be the same report as the feedback type 2E, and the calculation method of the S-CQI can be individually set.

  FIG. 11 shows an example of a procedure in uplink (UL) data transmission according to the present embodiment. First, the base station notifies the terminal device of UL grant, which is control information including allocation information indicating allocation of a physical uplink shared channel, which is a channel for uplink data transmission in the physical layer (step S1101). The terminal device notified of the UL grant transmits UL data using the physical uplink shared channel indicated by the allocation information (step S1002).

  In the periodic feedback mode, any feedback information (step S802, step S803, step S902, step S903, step S904, step S905, step S906, step S1002, step S1003, step S1004) is usually reported in the physical layer. Over a physical uplink control channel, which is a channel for reporting control information in However, when a physical uplink shared channel, which is a channel for transmitting data in the physical layer, is allocated at the timing at which any of these feedback information is reported in step S1101, the feedback information is the physical uplink shared channel. To be reported simultaneously with the UL data. The operation of reporting control information in the physical layer through the physical uplink shared channel instead of the physical uplink control channel is referred to as piggyback.

  Next, mapping of feedback information at the time of piggybacking in the periodic feedback mode will be described. FIG. 12 shows an example of feedback information mapping. The rearrangement and mapping shown in FIG. 12 are examples in the case of transmitting a plurality of CWs (CW0 and CW1) in the uplink. Here, it is assumed that CW0 and CW1 are transmitted using layer 1 and layer 2, respectively. Here, mapping at the time of piggybacking of feedback type 1A is shown.

  More specifically, the feedback information including RI and PI1 is a part or all of SC-FDMA symbols near ULRS in all layers (for example, layers 1, 2 and 2, 6, as shown in FIG. 12). Rearrangement is performed so as to be mapped to the 9th and 13th SC-FDMA symbols). That is, RI · PI1 transmits (reports) safely by a spatial multiplexing method independent of UL data (a method of substantially reducing the number of spatial multiplexing).

These rearrangement and mapping processes are performed by the uplink subframe generation unit 509 under the instruction of the higher layer 506. On the other hand, the feedback information extraction unit 409 in the base station apparatus uses the demapping corresponding to the mapping in the uplink subframe generation unit 509 and the rearrangement in the uplink subframe generation unit 509 based on the instruction of the higher layer 413. The feedback information is acquired by performing the rearrangement process to return to step (b).

  Here, a code book used for calculating PI1 and PI2 at the time of piggybacking in the periodic feedback mode will be described. As the code book, a code book similar to the code book in the non-periodic feedback mode is used. However, in the periodic feedback mode, feedback is reduced by reducing the degree of freedom in selecting W (i, j) in the code book. The overhead due to information can be reduced.

  More specifically, a possible value of the index i that can be expressed as m1 as PI1 is partially extracted (subsampled) from 0, 1,..., 2m−1, and the number of bits required for PI1 is m. Set to a value smaller than bits. Similarly, the number of bits required for PI2 is set to a value smaller than n bits. By limiting the types of W (i, j) that can be expressed by PI1 and PI2, the number of bits of PI1 and PI2 can be suppressed.

  As described above, when reporting PI1 through the physical uplink shared channel in the aperiodic feedback mode, PI1 is multiplexed into one CW. On the other hand, when PI1 is reported through the physical uplink shared channel during piggybacking in the periodic feedback mode, PI1 is multiplexed on all CWs. In other words, in the aperiodic feedback mode, when PI1 is reported through the physical uplink shared channel, PI1 is spatially multiplexed and transmitted in the same manner as UL data. On the other hand, when PI1 is reported via the physical uplink shared channel during piggybacking in the periodic feedback mode, a spatial multiplexing method in which PI1 is independent of UL data (a method in which the number of spatial multiplexing is substantially 1) Send with.

  As a result, when receiving quality information is reported via the physical uplink shared channel, if the received quality information can cause error propagation, it is transmitted in a safe manner, and the received quality information does not cause error propagation. Can be transmitted in a manner that reduces overhead. Therefore, efficient reception quality information feedback can be performed.

  In addition, when PI1 or PI2 is reported through the physical uplink shared channel in the aperiodic feedback mode, the PI1 or PI2 codebook is not subsampled. On the other hand, when PI1 or PI2 is reported through the physical uplink shared channel during piggyback in the periodic feedback mode, the PI1 or PI2 codebook is subsampled. In other words, a suitable precoder is selected from some candidates among a plurality of suitable precoder candidates. That is, in the aperiodic feedback mode, when PI1 or PI2 is reported through the physical uplink shared channel, PI1 or PI2 that can be expressed by X bits is transmitted. On the other hand, when PI1 or PI2 is reported through the physical uplink shared channel during piggyback in the periodic feedback mode, PI1 or PI2 that can be expressed by Y bits (Y <X) is transmitted.

  Thus, when reporting reception quality information via the physical uplink shared channel, detailed reception quality information is transmitted when a CQI request is received, and overhead is suppressed when a CQI request is not received. Can be sent. Therefore, efficient reception quality information feedback can be performed.

In the above description, the case where PI1 is reported in each feedback mode has been described. However, the present invention is not limited to this. For example, PI1 may not be reported when the number of transmission antennas of the base station apparatus is small. In this case, a suitable precoder may be a code book that is uniquely determined only from PI2. The feedback type including PI1 may be a feedback type for reporting content other than PI1.

  A program for realizing the functions of all or part of the base station apparatus or all or part of the terminal apparatus is recorded on a computer-readable recording medium, and the program recorded on the recording medium is recorded on the computer. The processing of each unit may be performed by reading it into the system and executing it. Here, the “computer system” includes an OS and hardware such as peripheral devices.

  Further, the “computer system” includes a homepage providing environment (or display environment) if a WWW system is used.

  The “computer-readable recording medium” refers to a storage device such as a flexible medium, a magneto-optical disk, a portable medium such as a ROM and a CD-ROM, and a hard disk incorporated in a computer system. Furthermore, the “computer-readable recording medium” dynamically holds a program for a short time like a communication line when transmitting a program via a network such as the Internet or a communication line such as a telephone line. In this case, a volatile memory in a computer system serving as a server or a client in that case, and a program that holds a program for a certain period of time are also included. The program may be a program for realizing a part of the functions described above, and may be a program capable of realizing the functions described above in combination with a program already recorded in a computer system.

  Further, the functions of all or part of the base station apparatus and all or part of the terminal apparatus may be integrated and realized in an integrated circuit. Each functional block of the base station apparatus and the terminal apparatus may be individually chipped, or a part or all of them may be integrated into a chip. Further, the method of circuit integration is not limited to LSI, and may be realized by a dedicated circuit or a general-purpose processor. In addition, when an integrated circuit technology that replaces LSI appears due to progress in semiconductor technology, an integrated circuit based on the technology can also be used.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and includes design changes and the like within a scope not departing from the gist of the present invention. The present invention can be modified in various ways within the scope of the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments are also included in the technical scope of the present invention. It is. Moreover, it is the element described in each said embodiment, and the structure which substituted the element which has the same effect is also contained.

  In one aspect of the present invention, the terminal device is a terminal device that communicates with the base station device, and when the reception quality information is reported together with the data via the channel used for data transmission, the reception quality information is not When the reception quality information is periodically reported, the reception quality information is reported by the same spatial multiplexing method as the spatial multiplexing method of the data, and the reception quality information is periodically reported reception quality information. The reception quality information is reported by a spatial multiplexing method independent of the data spatial multiplexing method.

  A terminal apparatus according to an aspect of the present invention is the terminal apparatus described above, wherein the reception quality information is one partial precoder information among a plurality of partial precoder information designating a suitable precoder. To do.

A terminal apparatus according to an aspect of the present invention is a terminal apparatus that communicates with a base station apparatus, and when receiving reception quality information together with data via a channel used for data transmission, the reception quality information is not If the reception quality information is periodically reported, report partial precoder information specifying at least one candidate from a plurality of suitable precoder candidates, and the reception quality information is periodically reported reception quality information. In some cases, partial precoder information for designating at least one candidate among a plurality of candidates among the plurality of suitable precoder candidates is reported.

  A base station apparatus according to an aspect of the present invention is a base station apparatus that communicates with a terminal apparatus, and extracts reception quality information reported together with data from the terminal apparatus via a channel used for data transmission. In this case, when the reception quality information is the reception quality information reported aperiodically, the reception quality information is extracted as being the same spatial multiplexing method as the spatial multiplexing method of the data, and the reception quality information The received quality information is extracted as a spatial multiplexing method independent of the data spatial multiplexing method.

  Also, a base station apparatus according to an aspect of the present invention is the above base station apparatus, wherein the reception quality information is one partial precoder information among a plurality of partial precoder information designating a suitable precoder. Features.

  A base station apparatus according to an aspect of the present invention is a base station apparatus that communicates with a terminal apparatus, and extracts reception quality information reported together with data from the terminal apparatus via a channel used for data transmission. In this case, when the reception quality information is reception quality information reported aperiodically, partial precoder information designating at least one candidate is extracted from a plurality of suitable precoder candidates, and the reception quality information is periodically In the case of the reception quality information to be reported automatically, partial precoder information designating at least one candidate is extracted from some candidates of the plurality of suitable precoder candidates.

  A communication system according to an aspect of the present invention is a communication system that performs communication between a base station apparatus and a terminal apparatus, and the terminal apparatus receives reception quality information together with data via a channel used for data transmission. When the reception quality information is the reception quality information reported aperiodically, the reception quality information is reported by the same spatial multiplexing method as the spatial multiplexing method of the data, and the reception quality information is The reception quality information is reported by a spatial multiplexing method independent of the data spatial multiplexing method, and the base station apparatus is reported together with the data from the terminal apparatus. When extracting the received quality information, if the received quality information is received quality information reported aperiodically, the received quality information is the same as the spatial multiplexing method of the data. If the received quality information is periodically reported reception quality information, the received quality information is extracted as a spatial multiplexing method independent of the data spatial multiplexing method. It is characterized by that.

  A communication system according to an aspect of the present invention is a communication system that performs communication between a base station apparatus and a terminal apparatus, and the terminal apparatus receives reception quality information together with data via a channel used for data transmission. When the reception quality information is non-periodically reported reception quality information, a partial precoder information designating at least one candidate from a plurality of suitable precoder candidates is reported, and the reception quality information Is the reception quality information that is periodically reported, reports partial precoder information that specifies at least one candidate from some of the plurality of suitable precoder candidates, the base station apparatus, When the reception quality information reported together with the data is extracted from the terminal device, the reception quality information is reception quality information reported aperiodically. A partial precoder information specifying at least one candidate from a plurality of candidates of the preferred precoder, and when the reception quality information is periodically reported reception quality information, Partial precoder information that specifies at least one candidate is extracted from some of the candidates.

  A communication method according to an aspect of the present invention is a communication method in a terminal apparatus that communicates with a base station apparatus, and reports reception quality information together with data via a channel used for data transmission. When the information is reception quality information reported aperiodically, the reception quality information is reported by the same spatial multiplexing method as the data spatial multiplexing method, and the reception quality information is periodically reported. The reception quality information may be reported by a spatial multiplexing method independent of the data spatial multiplexing method.

  A communication method according to an aspect of the present invention is a communication method in a terminal apparatus that communicates with a base station apparatus, and reports reception quality information together with data via a channel used for data transmission. If the information is reception quality information reported aperiodically, report partial precoder information specifying at least one candidate from a plurality of suitable precoder candidates, and receive the reception quality information periodically reported In the case of quality information, the method includes a step of reporting partial precoder information that designates at least one candidate from some of the plurality of candidates of the suitable precoder.

  A communication method according to an aspect of the present invention is a communication method in a base station device that communicates with a terminal device, and reception quality information reported together with data from the terminal device via a channel used for data transmission. When the reception quality information is reception quality information reported aperiodically, the reception quality information is extracted as being the same spatial multiplexing method as the data spatial multiplexing method, and the reception quality information is extracted. If the received quality information is periodically reported, the received quality information is extracted as a spatial multiplexing method independent of the data spatial multiplexing method.

  A communication method according to an aspect of the present invention is a communication method in a base station device that communicates with a terminal device, and reception quality information reported together with data from the terminal device via a channel used for data transmission. In the case where the reception quality information is aperiodically reported reception quality information, partial precoder information specifying at least one candidate is extracted from a plurality of suitable precoder candidates, and the reception quality information is extracted. A partial precoder information specifying at least one candidate from a plurality of candidates among the plurality of candidates of the preferred precoder, To do.

  The present invention is suitable for use in a wireless terminal device, a wireless base station device, a wireless communication system, and a wireless communication method.

101, 1301 ... base station apparatus 102, 1302 ... terminal apparatus 103, 1303 ... downlink transmission signal 104, 1304 ... feedback information 401 ... downlink subframe generation unit 402 ... physical downlink control channel generation unit 403 ... downlink reference signal generation Unit 404 ... OFDM signal transmission unit 405 ... transmission antenna 406 ... reception antenna 407 ... SC-FDMA signal reception unit 408 ... filter unit 409 ... feedback information extraction unit 410 ... code word processing unit 411 ... upper layer 501 ... reception antenna 502 ... OFDM Signal receiving unit 503 ... downlink subframe processing unit 504 ... downlink reference signal extracting unit 505 ... physical downlink control channel extracting unit 506 ... upper layer 507 ... feedback information generating unit 508 ... codeword generating unit 509 ... uplink subframe Generating unit 510 ... uplink reference signal generation unit 511 ... SC-FDMA signal transmitting unit 512 ... transmitting antenna

Claims (5)

A terminal device that communicates with a base station device,
When reporting reception quality information together with data to the base station apparatus via a channel used for data transmission,
If the reception quality information is reception quality information reported aperiodically, select a suitable precoder from the precoder candidates defined in the codebook, and report partial precoder information specifying the precoder,
A part for selecting a suitable precoder from candidates pre -sampled from the precoder candidates defined in the codebook and specifying the precoder when the reception quality information is periodically reported reception quality information A terminal device that reports precoder information. A base station device that communicates with a terminal device,
When extracting the reception quality information reported together with the data from the terminal device through the channel used for data transmission,
When the reception quality information is reception quality information reported aperiodically, a suitable precoder is selected from the precoder candidates specified in the codebook, and the partial precoder information specifying the precoder is extracted.
A part for selecting a suitable precoder from candidates pre -sampled from the precoder candidates defined in the codebook and specifying the precoder when the reception quality information is periodically reported reception quality information A base station device that extracts precoder information. A communication system for communicating between a base station device and a terminal device,
The terminal device
When reporting reception quality information together with data to the base station apparatus via a channel used for data transmission,
If the reception quality information is reception quality information reported aperiodically, select a suitable precoder from the precoder candidates defined in the codebook, and report partial precoder information specifying the precoder,
A part for selecting a suitable precoder from candidates pre -sampled from the precoder candidates defined in the codebook and specifying the precoder when the reception quality information is periodically reported reception quality information Report precoder information,
The base station device
In extracting the reception quality information reported together with the data from the terminal device,
If the reception quality information is reception quality information reported aperiodically, a suitable precoder is selected from the precoder candidates defined in the codebook, and partial precoder information specifying the precoder is extracted. ,
A part for selecting a suitable precoder from candidates pre -sampled from the precoder candidates defined in the codebook and specifying the precoder when the reception quality information is periodically reported reception quality information A communication system that extracts precoder information. A communication method in a terminal device that communicates with a base station device,
When reporting reception quality information along with data via the channel used for data transmission,
If the reception quality information is reception quality information reported aperiodically, select a suitable precoder from the precoder candidates defined in the codebook, and report partial precoder information specifying the precoder,
A part for selecting a suitable precoder from candidates pre -sampled from the precoder candidates defined in the codebook and specifying the precoder when the reception quality information is periodically reported reception quality information A communication method comprising reporting precoder information. A communication method in a base station device that communicates with a terminal device,
When extracting the reception quality information reported together with the data from the terminal device through the channel used for data transmission,
When the reception quality information is reception quality information reported aperiodically, a suitable precoder is selected from the precoder candidates specified in the codebook, and the partial precoder information specifying the precoder is extracted.
A part for selecting a suitable precoder from candidates pre -sampled from the precoder candidates defined in the codebook and specifying the precoder when the reception quality information is periodically reported reception quality information A communication method comprising a step of extracting precoder information.

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