JP2014017835A - Terminal device, base station device, communication method, and integrated circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently perform communication in a communication system which performs communication between mobile terminals and a base station in which precoding matrices based on a plurality of types of code books are stipulated.SOLUTION: A terminal device notifies a base station device of information indicating whether the terminal device supports a transmission mode using reference signals for measuring transmission path states of 8 antenna ports. The base station device is notified by the terminal device of the information indicating whether the terminal device supports the transmission mode using the reference signals for measuring transmission path states of 8 antenna ports.

Description

  The present invention relates to a terminal device, a base station device, a communication method, and an integrated circuit.

  3CDMA (Third Generation Partnership Project) WCDMA (Wideband Code Divide Multiple Access), LTE (Long Term Evolution), LTE-A (LTE-Advanced) Stations and mobile terminals are each provided with a plurality of transmission / reception antennas, and high-speed data transmission can be realized by MIMO (Multi Input Multi Output) technology.

  In such a radio communication system, a transmission path condition between a base station and a mobile terminal is estimated by using a reference signal for transmission path condition measurement composed of a known signal between the base station and the mobile terminal. Based on the estimation results, the modulation scheme and coding rate (MCS (Modulation and Coding Scheme)), spatial multiplexing number (number of layers, rank), precoding weight (precoding matrix, precoder), etc. are adaptively applied. By controlling, more efficient data transmission can be realized. For example, the method described in Non-Patent Document 1 can be used.

  FIG. 11 is a block diagram illustrating an example in which adaptive control is performed when a downlink (downlink, downlink) in which data transmission from the base station 1100 to the mobile terminal 1110 is considered.

  In base station 1100, first, in multiplexing section 1102, reference signal for channel condition measurement specific to the base station (CSI-RS (Channel State Information-Reference Signal), pilot signal, known signal) is transmitted to mobile terminal 1110. It is multiplexed with a data signal or a data signal addressed to another mobile terminal and transmitted from the transmission antenna 1103. In the mobile terminal 1110, the separation unit 1112 separates the transmission path condition measurement reference signal from the signal received by the reception antenna 1111. The feedback information generation unit 1113 generates feedback information based on the transmission path condition measurement reference signal, and transmits the feedback information from the transmission antenna 1114 via the uplink (uplink, uplink). In the base station 1100, the feedback information processing unit 1105 identifies and processes the feedback information transmitted from the mobile terminal 1110 from the signal received by the receiving antenna 1104. Adaptive control section 1101 performs adaptive control on the data signal for mobile terminal 1110 based on the received feedback information.

  On the other hand, in a radio communication system, there are mobile terminals having various capabilities (performance and capability) in an area covered by a base station. Therefore, the base station can accommodate such mobile terminals by knowing the mobile terminal capabilities (mobile terminal capabilities). As such a control method, for example, the method described in Non-Patent Document 2 can be used.

  FIG. 12 is a diagram illustrating an example of control for notifying the mobile station capability from the mobile terminal to the base station. The base station 1201 notifies the mobile terminal 1202 of a mobile terminal capability inquiry (UECapabilityEnquiry) 1203 through RRC (Radio Resource Control Signaling) signaling or the like. The mobile terminal 1202 notifies the mobile station capability information (UECapabilityInformation) 1204 to the base station 1201 through RRC signaling. As the mobile terminal capability information, for example, information described in Non-Patent Document 3 can be used.

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 TS 36.213 V8.8.0 (2009-9 ) 3rd Generation Partnership Project; Technical Specification Group Radio Access Network; Evolved Universal Terrestrial Radio Access (E-UTRA) Radio Resource Control (RRC); Protocol specification (Release 8), 12 May 2009, 3GPP TS 36.331 V8.8. 0 (2009-12) 3rd Generation Partnership Project; Technical Specification Group Radio Access Network; Evolved Universal Terrestrial Radio Access (E-UTRA) User Equipment (UE) radio access capabilities (Release 8), 9 September 2009, 3GPP TS 36.306 V8.5.0 (2009-09)

  However, in the conventional communication scheme, when a precoding matrix by a plurality of types of codebooks is defined, the codebook supported by the mobile terminal cannot be shared between the base station and the mobile terminal, It was difficult to specify and apply a precoder, which hindered improvement in transmission efficiency.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a mobile terminal in a communication system that performs communication between a base station and a mobile terminal in which precoding matrices based on a plurality of types of codebooks are defined. Is to provide a terminal device, a base station device, a communication system, and a communication method that can share a codebook supported by the base station and a mobile terminal.

  (1) A terminal apparatus according to an aspect of the present invention is a terminal apparatus that communicates with a base station apparatus, and a codebook that defines a PMI indicating a precoding matrix that the terminal apparatus feeds back to the base station apparatus is transmitted. A plurality of reference signals for channel condition measurement are defined in advance according to the number of antenna ports of the path condition measurement reference signal, and among a plurality of transmission path condition measurement reference signals set according to the number of antenna ports, only for a specific number of antenna ports The base station apparatus is notified using the mobile terminal capability information indicating the capability of the terminal apparatus whether the reference signal for transmission path condition measurement corresponding to the code book defined in the above is supported.

  (2) Moreover, the terminal device by 1 aspect of this invention is the said terminal device, Comprising: The said specific antenna port number is eight.

  (3) Moreover, the terminal device according to an aspect of the present invention is the terminal device described above, and the codebook defined only for the specific number of antenna ports is a transmission mode set by the base station, Used only when a specific transmission mode is set.

  (4) In addition, a terminal device according to an aspect of the present invention is the above-described terminal device, and the specific transmission mode is a transmission method in which an information data signal is transmitted in a maximum of 8 layers.

  (5) In addition, a terminal device according to an aspect of the present invention is the terminal device described above, and the transmission path condition measurement reference signal defined for the specific number of antenna ports is the base station device and the terminal device. Code division multiplexing and frequency division multiplexing are performed between antenna ports using signals known to each other.

  (6) A base station apparatus according to an aspect of the present invention is a base station apparatus that communicates with a terminal apparatus, and a codebook that defines a PMI indicating a precoding matrix that the terminal apparatus feeds back to the base station apparatus Are defined in advance according to the number of antenna ports of the transmission path condition measurement reference signal, and the mobile terminal capability information indicating the capabilities of the terminal device is notified to the base station device to the terminal device. Mobile terminal capability information notified by the terminal device based on the instruction, and the mobile terminal capability information is a plurality of channel state measurement reference signals set according to the number of antenna ports. Support for the channel state measurement reference signal corresponding to the codebook defined only for a specific number of antenna ports. Including whether your door.

  (7) A communication system according to an aspect of the present invention is a communication system in which a base station apparatus and a terminal apparatus communicate with each other, and defines a PMI indicating a precoding matrix that the terminal apparatus feeds back to the base station apparatus. A plurality of codebooks are preliminarily defined according to the number of antenna ports of the transmission path condition measurement reference signal, and the base station apparatus transmits mobile terminal capability information indicating the capabilities of the terminal apparatus to the terminal apparatus. Instructing the base station apparatus to notify, the terminal apparatus, based on the instruction, out of a plurality of channel state measurement reference signals set according to the number of antenna ports, only a specific number of antenna ports Whether or not the reference signal for transmission path condition measurement corresponding to the code book defined for Using the information, notifying the base station apparatus.

    (8) A communication method according to an aspect of the present invention is a communication method for a terminal apparatus that communicates with a base station apparatus, and specifies a PMI indicating a precoding matrix that the terminal apparatus feeds back to the base station apparatus. A plurality of codebooks are defined in advance according to the number of antenna ports of the transmission path condition measurement reference signal. Among the plurality of transmission path condition measurement reference signals set according to the number of antenna ports, a specific antenna is selected. The mobile station capability information indicating the capability of the terminal device is notified to the base station device whether a reference signal for transmission path condition measurement corresponding to a code book defined only for the number of ports is supported. .

  (9) A communication method according to an aspect of the present invention is a communication method of a base station apparatus that communicates with a terminal apparatus, and specifies a PMI indicating a precoding matrix that the terminal apparatus feeds back to the base station apparatus. A plurality of codebooks are defined in advance according to the number of antenna ports of the reference signal for transmission path condition measurement, and mobile terminal capability information indicating the capabilities of the terminal device is notified to the base station device to the terminal device Mobile terminal capability information notified by the terminal device based on the instruction, the mobile terminal capability information is a plurality of channel state measurement reference signals set according to the number of antenna ports Among them, a reference signal for measuring the transmission path status corresponding to the codebook defined only for a specific number of antenna ports. The including whether the support.

  According to the present invention, the codebook supported by the mobile terminal can be shared between the base station and the mobile terminal.

It is an example of the mobile terminal capability information used in the 1st Embodiment of this invention. It is an example of the mobile terminal category used in the first embodiment of the present invention. It is a figure which shows the resource block pair by which the reference signal for transmission path condition measurement for 8 antenna ports was mapped. It is a figure which shows the resource block pair by which the reference signal for transmission-path condition measurement for 4 antenna ports was mapped. It is a figure which shows an example of the code book prescribed | regulated according to the number of ports of the reference signal for transmission-path condition measurement. It is a figure which shows an example of the transmission mode used in the 1st Embodiment of this invention. It is a figure which shows an example of the code book prescribed | regulated according to the port number and transmission mode of the reference signal for transmission path condition measurement. It is an example of the mobile terminal capability information used in the 2nd Embodiment of this invention. It is a figure which shows an example of the code book prescribed | regulated according to the maximum space multiplexing number in a downlink. It is a figure which shows an example of the code book prescribed | regulated according to a mobile terminal category. It is a block diagram which shows an example which performs adaptive control at the time of considering the downlink (downlink, downlink) which performs the data transmission from the base station 1100 to the mobile terminal 1110. It is a figure which shows an example of the control which notifies a mobile terminal capability from a mobile terminal to a base station.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described. The communication system in the first embodiment includes a base station (base station apparatus, transmission apparatus, cell, transmission point, transmission antenna group, transmission antenna port group, component carrier, eNodeB, first communication apparatus) and mobile terminal ( A terminal device, a reception point, a reception terminal, a reception device, a second communication device, a reception antenna group, a reception antenna port group, and a UE (User Equipment).

  In the communication system according to the first embodiment, first, the base station notifies the mobile terminal of a mobile terminal capability inquiry (terminal device capability inquiry, UE capability inquiry, UE capability inquiry), and mobile terminal capability information ( The terminal apparatus capability information, UE capability information, and UE capability information) are instructed to be transmitted. The mobile terminal transmits mobile terminal capability information to the base station based on the mobile terminal capability inquiry from the base station.

  FIG. 1 is an example of mobile terminal capability information used in the first embodiment of the present invention. The mobile terminal capability information includes mobile terminal category, carrier aggregation information in the downlink (DL), maximum spatial multiplexing number in the downlink, support for reference signals for 8 antenna port transmission path condition measurement in the downlink, uplink (UL). ; Uplink), the carrier aggregation information, and the maximum spatial multiplexing number in the uplink.

  FIG. 2 is an example of the mobile terminal category used in the first embodiment of the present invention. The mobile terminal category includes the maximum data rate in the downlink and the uplink, and the maximum spatial multiplexing number in the downlink. The mobile terminal category shown in FIG. 2 is composed of eight mobile terminal categories according to these parameters. In the case of mobile terminal categories 6 to 8, the maximum spatial multiplexing number in the downlink is not notified in the mobile terminal category, but is notified by the mobile terminal capability shown in FIG.

  The carrier aggregation information in the downlink and uplink shown in FIG. 1 is a combination of the number of component carriers to be aggregated (integrated and aggregated) and the frequency bandwidth (system bandwidth) for each component carrier in the downlink and uplink, respectively. A combination (parameter) that can be transmitted / received by the mobile terminal is indicated. As specific information, for example, information in a bitmap format corresponding to each combination, a method of selecting one of the maximum parameters that can be transmitted / received by the mobile terminal, and the like can be used. Further, the number of component carriers and the frequency bandwidth may be independent parameters.

  The maximum spatial multiplexing number in the downlink and uplink shown in FIG. 1 indicates the maximum spatial multiplexing number that the mobile terminal can transmit and receive in the downlink and uplink. Note that the maximum spatial multiplexing number in the downlink indicated in the mobile terminal capability information is used for mobile terminal categories 6 to 8 shown in FIG. That is, in the case of the mobile terminal categories 1 to 5 shown in FIG. 2, it is not necessary to notify the maximum number of spatial multiplexing in the downlink indicated in the mobile terminal capability information. Even in the case of mobile terminal categories 1 to 5 shown in FIG. 2, the mobile terminal may notify the maximum number of spatial multiplexing in the downlink indicated in the mobile terminal capability information. In that case, the base station can preferentially adopt either the maximum spatial multiplexing number in the downlink indicated by the mobile terminal capability information or the maximum spatial multiplexing number in the downlink indicated by the mobile terminal category.

  The support of the 8-antenna port transmission path condition measurement reference signal in the downlink shown in FIG. 1 (support of antenna ports 15 to 22) is supported by the mobile terminal supporting the transmission path condition measurement reference signal for 8 antenna ports. It is information indicating whether or not. The antenna port is also referred to as a resource grid. For example, when the mobile terminal supports an 8-antenna port transmission path condition measurement reference signal, the support of the 8-antenna port transmission path condition measurement reference signal indicates “1”. Further, when the mobile terminal does not support the 8-antenna port transmission path condition measurement reference signal, the support of the 8-antenna port transmission path condition measurement reference signal indicates “0”.

  In the following, the effect of the mobile terminal notifying the base station of support of the 8-antenna port transmission path condition measurement reference signal will be described.

  FIG. 3 is a diagram showing a resource block pair to which a channel state measurement reference signal for 8 antenna ports is mapped. FIG. 3 shows a case where the channel state measurement reference signal is mapped when the number of antenna ports (the number of CSI ports) of the base station is 8. FIG. 3 shows two resource blocks in one subframe, and one resource block pair is configured. One resource block is composed of 12 subcarriers in the frequency direction and 7 OFDM symbols in the time direction. Each subcarrier in one OFDM symbol is also referred to as a resource element. Of each subframe, the seven OFDM symbols before and after in the time direction are also referred to as slots.

  Here, the number of resource blocks can be changed according to the frequency bandwidth (system bandwidth) used by the communication system. For example, 6 to 110 resource blocks can be used, and the total system bandwidth can be increased to 110 or more by carrier aggregation (frequency aggregation). Usually, the component carrier is composed of 100 resource blocks, and the total system bandwidth can be set to 500 resource blocks with five component carriers with a guard band between the component carriers. When this is expressed in terms of bandwidth, for example, the component carrier is composed of 20 MHz, and the total system bandwidth can be set to 100 MHz with five component carriers with the guard band between the component carriers.

  Among the colored resource elements of FIG. 3, the data signal demodulation reference signals of CDM group numbers 1 and 2 are represented as D1 to D2, respectively, and the channel state measurement reference signals of CDM group numbers 1 to 4 are represented as C1 to C4, respectively. ing. Further, the information data signal or the control information signal is mapped to resource elements other than the resource element to which those reference signals are mapped.

  For the channel state measurement reference signal, a 2-chip orthogonal code (Walsh code) is used in each CDM group, and the CSI port (port of the channel state measurement reference signal (antenna port, resource) is used for each orthogonal code. Grid)) is assigned, and code division multiplexing (CDM) is performed for each 2CSI port. Further, each CDM group is frequency division multiplexed. Reference signals for channel state measurement of 8 antenna ports of CSI ports 1 to 8 (antenna ports 15 to 22) are mapped using four CDM groups. For example, the CDM group C1 of the channel state measurement reference signal is mapped by CDMing the channel state measurement reference signals of the CSI ports 1 and 2 (antenna ports 15 and 16). The CDM group C2 of the transmission path condition measurement reference signal is obtained by CDM mapping the transmission path condition measurement reference signals of the CSI ports 3 and 4 (antenna ports 17 and 18). The CDM group C3 of the transmission path condition measurement reference signal is obtained by CDM mapping the transmission path condition measurement reference signals of the CSI ports 5 and 6 (antenna ports 19 and 20). The CDM group C4 of the channel state measurement reference signal CDM maps the channel state measurement reference signals of the CSI ports 7 and 8 (antenna ports 21 and 22).

  When the number of antenna ports of the base station is 8, the number of layers of information data signals or control information signals (number of ranks, number of spatial multiplexing, number of DMRS ports) can be a maximum of 8, for example, the number of layers of information data signals 2 and the number of layers of the control information signal can be 1. The reference signal for data signal demodulation is subjected to CDM every 2 layers or 4 layers by using orthogonal codes of 2 chips or 4 chips in each CDM group according to the number of layers. Further, each CDM group is frequency division multiplexed. By using two CDM groups, the 8-layer data signal demodulation reference signals of DMRS ports 1 to 8 (antenna ports 7 to 14) are mapped.

  FIG. 4 is a diagram showing resource block pairs to which channel state measurement reference signals for four antenna ports are mapped. FIG. 4 shows a case where a channel state measurement reference signal is mapped when the number of antenna ports of the base station is four.

  Among the colored resource elements in FIG. 4, the data signal demodulation reference signals of CDM group numbers 1 and 2 are represented as D1 and D2, respectively, and the transmission path condition measurement reference signals of CDM group numbers 1 and 2 are represented as C1 and C2, respectively. ing. Further, the information data signal or the control information signal is mapped to resource elements other than the resource element to which those reference signals are mapped.

  The reference signal for transmission path condition measurement uses a 2-chip orthogonal code (Walsh code) in each CDM group, a CSI port is assigned to each orthogonal code, and CDM is performed for each 2CSI port. Further, each CDM group is frequency division multiplexed. The reference signals for transmission path condition measurement of the four antenna ports of CSI ports 1 to 4 (antenna ports 15 to 18) are mapped using two CDM groups. For example, the CDM group C1 of the channel state measurement reference signal is mapped by CDMing the channel state measurement reference signals of the CSI ports 1 and 2 (antenna ports 15 and 16). The CDM group C2 of the transmission path condition measurement reference signal is obtained by CDM mapping the transmission path condition measurement reference signals of the CSI ports 3 and 4 (antenna ports 17 and 18).

  When the number of antenna ports of the base station is 4, the maximum number of layers of the information data signal or the control information signal can be 4. The reference signal for data signal demodulation is subjected to CDM every two layers using a two-chip orthogonal code in each CDM group according to the number of layers. Further, each CDM group is frequency division multiplexed. Using two CDM groups, four layers of data signal demodulation reference signals of DMRS ports 1 to 4 (antenna ports 7 to 10) are mapped.

  Further, the base station can transmit a transmission path condition measurement reference signal when the number of antenna ports is 1 or 2. The channel state measurement reference signal for 1 antenna port or 2 antenna port can be transmitted using the CDM group C1 of the channel state measurement reference signal shown in FIG. 3 or FIG.

  The mobile terminal measures the transmission path condition between the base station and the mobile terminal using the transmission path condition measurement reference signal transmitted from the base station, and provides feedback information for realizing adaptive control for the mobile terminal of the base station. Generate and feed back (notify) the base station.

  In particular, the mobile terminal can generate, as feedback information, a precoding matrix for the base station to perform precoding processing on an information data signal addressed to the mobile terminal. The precoding process is performed for the base station to optimally transmit an information data signal to the mobile terminal. For example, precoding processing is performed in order to facilitate separation of information data signals spatially multiplexed by the mobile terminal, or reception power (SNR: Signal to Noise power Ratio, SINR; Signal and Interference) of the information data signal received by the mobile terminal. to Noise power Ratio) can be performed for the purpose of optimization (maximum).

  In order to reduce the overhead of feedback information fed back by the mobile terminal, the precoding matrix is defined in advance as a code book and can be shared between the base station and the mobile terminal. Thereby, the mobile terminal can select an optimal precoding matrix from the specified codebook and feed back the index as a PMI (Precoding Matrix Indicator).

  Further, a plurality of codebooks can be defined. For example, the code book can be defined according to the number of ports of the transmission path condition measurement reference signal. FIG. 5 is a diagram illustrating an example of a code book defined in accordance with the number of ports of the transmission path condition measurement reference signal. When the number of ports of the transmission path condition measurement reference signal is 1, 2 or 4, code book 1 (first code book) is used. When the number of ports of the transmission path condition measurement reference signal is 8, codebook 2 (second codebook) is used.

  At this time, each code book can be defined for various purposes and reasons. For example, in order to maintain backward compatibility with a radio communication system (for example, LTE) in which the number of ports of the transmission path condition measurement reference signal is 1, 2 or 4, The specified codebook can be reused. Codebook 2 uses a codebook defined in a wireless communication system that does not need to consider backward compatibility with a wireless communication system operated with 1, 2, or 4 ports of a transmission path condition measurement reference signal. be able to. Further, for example, the code book 1 can be defined by a code book that is optimal for SU-MIMO (Single User-MIMO). The code book 2 can be further defined by a code book that is most suitable for MU-MIMO (Multi User-MIMO) or high-rank SU-MIMO.

  Here, when a plurality of types of codebooks are defined in the wireless communication system, specifically, as shown in FIG. 5, when codebooks are defined according to the number of ports of the transmission path condition measurement reference signal The mobile terminal needs to hold all the defined codebooks. That is, the mobile terminal needs to hold all the defined codebooks regardless of the maximum number of transmission path condition measurement reference signals that can be received by the mobile terminal.

  Therefore, the mobile terminal can solve such a problem by notifying the base station of support of the 8-antenna port transmission path condition measurement reference signal as mobile terminal capability information. That is, the mobile terminal that does not support the 8-antenna port transmission path condition measurement reference signal notifies the support of the 8-antenna port transmission path condition measurement reference signal as “0”, and thus the codebook 2 shown in FIG. There is no need to hold, and only the code book 1 can be held. Therefore, the storage capacity of the mobile terminal can be reduced, and the processing of the mobile terminal can be reduced. Furthermore, the base station can reduce scheduling processing and handover processing of mobile terminals including the mobile terminal.

  Also, the mobile terminal that supports the 8-antenna port transmission path condition measurement reference signal notifies the support of the 8-antenna port transmission path condition measurement reference signal as “1”. At this time, the mobile terminal preferably holds the code book 1 and the code book 2, but may hold only the code book 2.

  When the base station is notified of the support of the 8-antenna port transmission path condition measurement reference signal as “0” from the mobile terminal, the base station transmits to the mobile terminal a transmission method (transmission mode) other than the maximum eight-layer transmission method. ) Can be set. For example, the base station may set a transmission method (transmission mode) used in a radio communication system operated with 1, 2, or 4 ports of the transmission path condition measurement reference signal for the mobile terminal. it can.

  Also, when the base station is notified of the support of the 8-antenna port transmission path condition measurement reference signal from the mobile terminal as “1”, the base station transmits to the mobile terminal a transmission scheme including a transmission scheme of a maximum of eight layers transmission. (Transmission mode) can be set.

  FIG. 6 is a diagram illustrating an example of a transmission mode used in the first embodiment of the present invention. Among the transmission modes shown in FIG. 6, only the code book 1 is used for the transmission modes 4, 5, 6 and 8 for feeding back the PMI, and the code book 1 or the code book 2 is used for the transmission mode 9. In addition, the format of the control information signal (DCI (Downlink Control Information) format) corresponding to each transmission mode is defined. The transmission mode 9 may be defined such that only the code book 2 is used.

  At this time, when the support of the 8-antenna port transmission path condition measurement reference signal is notified as “0” from the mobile terminal, the base station sets one of transmission modes 1 to 8 for the mobile terminal. be able to.

  In addition, the support of the 8-antenna port transmission path condition measurement reference signal can be switched between the case of being notified and the case of not being notified depending on the mobile terminal category. For example, notification is made only when the mobile terminal category is 1-7. You may be made to do.

  In addition, when the base station is notified of the support of the 8-antenna port transmission path condition measurement reference signal as “1” from the mobile terminal, the base station sets one of the transmission modes 1 to 9 for the mobile terminal. Can do.

  Furthermore, in addition to the number of ports of the transmission path condition measurement reference signal, the code book can be defined according to the transmission mode. FIG. 7 is a diagram illustrating an example of a code book defined in accordance with the number of ports and the transmission mode of the transmission path condition measurement reference signal. Among the transmission modes shown in FIG. 6, codebook 1 is used for transmission modes 4, 5, 6, and 8 that feed back PMI. In transmission mode 9, codebook 1 is used when the number of ports of the transmission path condition measurement reference signal is 1, 2, and 4, and codebook 2 is used when the number of ports of the transmission path condition measurement reference signal is eight. . Further, the mobile terminal capability information may include information indicating whether or not the transmission mode 9 is supported as the support for the transmission mode 9 in addition to the support for the 8-antenna port transmission path condition measurement reference signal. Furthermore, each control information may be jointly coded and its index may be used as control information. Also, the mobile terminal capability information is used for 8-antenna port transmission path condition measurement as support for the 8-antenna port transmission path condition measurement reference signal and transmission mode 9, instead of supporting the 8-antenna port transmission path condition measurement reference signal. Information indicating whether the reference signal is receivable and the transmission mode 9 is supported may be included. Furthermore, support for the 8-antenna port transmission path condition measurement reference signal and transmission mode 9 can be switched between being notified and not being notified depending on the number of ports of the transmission path condition measurement reference signal of the base station. For example, you may make it notify only when the number of ports of the reference signal for a transmission path condition measurement of a base station is eight.

  Note that the mobile terminal capability information may include information indicating whether or not the transmission mode 9 is supported as support for the transmission mode 9 instead of support for the 8-antenna port transmission path condition measurement reference signal. Furthermore, the support of transmission mode 9 can be switched between the case of being notified and the case of not being notified according to the number of ports of the reference signal for transmission path status measurement of the base station. You may make it notify only when the number of ports of a reference signal is eight.

  Note that the mobile terminal capability information may include information indicating whether or not the DCI format 1C is supported as support for the DCI format 1C, instead of supporting the 8-antenna port transmission path condition measurement reference signal. Furthermore, the support of the DCI format 1C can be switched between the case of being notified and the case of not being notified according to the number of ports of the transmission path state measurement reference signal of the base station. You may make it notify only when the number of ports of a reference signal is eight.

  Note that the mobile terminal capability information may include information indicating whether or not the code book 2 is supported as the support of the code book 2 instead of the support of the 8-antenna port transmission path condition measurement reference signal. Furthermore, the support of the code book 2 can be switched between the case of being notified and the case of not being notified depending on the number of ports of the reference signal for transmission path status measurement of the base station. You may make it notify only when the number of ports of a reference signal is eight.

  Note that the mobile terminal capability information includes the maximum number of receivable ports (maximum number of ports that can generate feedback information) of the reference signal for transmission path status measurement instead of support of the reference signal for measurement of transmission path status of 8 antenna ports. Also good. Further, the maximum number of receivable ports of the transmission path condition measurement reference signal can be switched between the case where it is notified and the case where it is not notified, depending on the number of ports of the transmission path condition measurement reference signal of the base station. You may make it notify only when the number of ports of the reference signal for transmission-path condition measurement of a base station is eight.

  In the above description, the support of the 8-antenna port transmission path condition measurement reference signal is notified as mobile terminal capability information, but the present invention is not limited to this. For example, support for an 8-antenna port transmission path condition measurement reference signal may be included in the mobile terminal category and notified. Further, the support of the 8-antenna port transmission path condition measurement reference signal can be notified in a control information signal or an information data signal transmitted through PDCCH (Physical Downlink Control Channel) or RRC signaling.

  In the above description, the support of the 8-antenna port transmission path condition measurement reference signal has been notified as independent control information. However, control information synthesized with other control information is defined, that is, joint coding is performed. The information indicating the index can be notified as control information. For example, support for 8-antenna port transmission path condition measurement reference signal includes support for mobile terminal category, downlink carrier aggregation information, maximum spatial multiplexing number in downlink, and 8-antenna port transmission path condition measurement reference signal in downlink. In addition, the carrier aggregation information in the uplink, the maximum spatial multiplexing number in the uplink, the maximum data rate in the downlink and the uplink, the transmission mode, the DCI format, etc. can be jointly coded and notified.

As described above, the mobile terminal explicitly (explicitly) transmits the codebook supported by the mobile terminal to the base station having the precoder defined in the plurality of codebooks through the mobile terminal capability information. By notifying, the storage capacity of the mobile terminal can be reduced, and the processing of the mobile terminal can be reduced. Furthermore, the base station can reduce scheduling processing and handover processing of mobile terminals including the mobile terminal.
(Second Embodiment)
Hereinafter, a second embodiment of the present invention will be described. The communication system according to the second embodiment includes a base station and a mobile terminal, similarly to the communication system according to the first embodiment of the present invention. Below, it demonstrates centering on a different part from the 1st Embodiment of this invention.

  FIG. 8 is an example of mobile terminal capability information used in the second embodiment of the present invention. The mobile terminal capability information is configured to include a mobile terminal category, downlink carrier aggregation information, the maximum spatial multiplexing number in the downlink, the carrier aggregation information in the uplink, and the maximum spatial multiplexing number in the uplink.

  In the second embodiment, by associating with a part of the mobile terminal capability information shown in FIG. 8, the codebook supported by the mobile terminal is notified implicitly (implicitly or implicitly).

  For example, the codebook supported by the mobile terminal can be notified in association with the maximum spatial multiplexing number in the downlink of the mobile terminal capability information shown in FIG.

  FIG. 9 is a diagram illustrating an example of a code book defined according to the maximum spatial multiplexing number in the downlink. When the maximum spatial multiplexing number in the downlink is 1, 2 or 4, codebook 1 is used. When the maximum spatial multiplexing number in the downlink is 8, codebook 2 is used.

  As a result, the mobile terminal having the maximum spatial multiplexing number of 1, 2, or 4 in the receivable downlink, that is, the mobile terminal having the maximum spatial multiplexing number of 1, 2, or 4 in the downlink notified by the mobile terminal capability is There is no need to hold the book 2, the storage capacity of the mobile terminal can be reduced, and the processing of the mobile terminal can be reduced. Furthermore, the base station can reduce scheduling processing and handover processing of mobile terminals including the mobile terminal.

  For example, the codebook supported by the mobile terminal can be notified in association with the mobile terminal category of the mobile terminal capability information shown in FIG.

  FIG. 10 is a diagram illustrating an example of a code book defined according to a mobile terminal category. When the mobile terminal category is 1, 2, 3, 4, 5, 6, 7, codebook 1 is used. When the mobile terminal category is 8, codebook 2 is used.

  As a result, the mobile terminal category is 1, 2, 3, 4, 5, 6, 7; that is, the mobile terminal category to be notified by the mobile terminal capability is 1, 2, 3, 4, 5, 6, 7 The mobile terminal does not need to hold the code book 2, the storage capacity of the mobile terminal can be reduced, and the processing of the mobile terminal can be reduced. Furthermore, the base station can reduce scheduling processing and handover processing of mobile terminals including the mobile terminal.

  In the above description, a case has been described in which the codebook supported by the mobile terminal is notified to the implicit in association with the maximum spatial multiplexing number or the mobile terminal category in the downlink, but is not limited thereto. . For example, the codebook supported by the mobile terminal includes carrier aggregation information in the downlink, the number of ports of the reference signal for transmission path condition measurement in the downlink, carrier aggregation information in the uplink, the maximum spatial multiplexing number in the uplink, the downlink It is also possible to notify the implicit in association with each maximum data rate, transmission mode, DCI format, etc. in the uplink.

  In the above description, the codebook supported by the mobile terminal by being associated with a part of the mobile terminal capability information has been described as being reported to the implicit. However, the present invention is not limited to this. For example, the codebook supported by the mobile terminal may be associated with a part of the mobile terminal category information. Also, the codebook supported by the mobile terminal can be notified in association with a control information signal, an information data signal, or the like transmitted through PDCCH or RRC signaling.

As described above, the mobile terminal implicitly (implicitly) reports the codebook supported by the mobile terminal to the base station having the precoder defined in the plurality of codebooks through the mobile terminal capability information. By doing so, the storage capacity of the mobile terminal can be reduced, and the processing of the mobile terminal can be reduced. Furthermore, the base station can reduce scheduling processing and handover processing of mobile terminals including the mobile terminal.
(Third embodiment)
In the first or second embodiment, the explicit or implicit notification of whether or not the codebook 2 can be supported in one cell has been described. In the third embodiment of the present invention, a description is given of the notification of whether codebook 2 is supported and the subsequent processing when one mobile terminal is accommodated in cells (base stations) having different antenna port numbers.

  A mobile terminal that supports code book 2 that is a code book for 8 antenna ports supports code book 2 that is itself a code book for 8 antenna ports by using mobile terminal capability information as shown in FIG. To explicitly notify the base station. On the other hand, a mobile terminal that does not support (does not have) the code book 2 that is a code book for 8 antenna ports uses the mobile terminal capability information as shown in FIG. It explicitly notifies the base station that it does not support a certain codebook 2.

  Alternatively, the mobile terminal supporting the code book 2 that is a code book for 8 antenna ports uses the mobile terminal capability information as shown in FIG. 8 to use the code book 2 that is a code book for 8 antenna ports. Implicitly notify the base station that it supports On the other hand, a mobile terminal that does not support (does not have) the code book 2 that is a code book for 8 antenna ports uses the mobile terminal capability information as shown in FIG. Implicitly notify the base station that it does not support a certain codebook 2.

  When the base station is a base station that performs transmission using 1, 2 or 4 antenna ports (ie, a cell of 1, 2 or 4 ports), the base station uses the codebook 1 as shown in FIG. Modes 4, 5, 6, 8, and 9 can be used. Since both mobile terminals that support codebook 2 and mobile terminals that do not support codebook 1 can use codebook 1, the base station may set modes 4, 5, 6, 8, and 9 for both mobile terminals. it can. Here, modes 1 to 8 are basic transmission modes, and mode 9 is an extended transmission mode. The extended transmission mode is a transmission mode whose function is expanded compared to the basic transmission mode, and is excellent in terms of the degree of freedom of scheduling, the overhead of control information, the maximum transmission rate, and the like.

  On the other hand, if the base station is a base station that performs transmission with 8 antenna ports (ie, a cell with 8 ports), the base station uses mode 4 and 5 as the transmission mode using codebook 1 as shown in FIG. -Mode 9 can be used as a transmission mode using 6. 8 and codebook 2. The base station can set modes 4, 5, 6, 8, and 9 for mobile terminals that support codebook 2. Also, mode 9 is not set for a mobile terminal that does not support codebook 2.

  In this way, the mobile terminal that does not support the codebook 2 can also be notified by explicitly or implicitly notifying the support of the codebook 2 that is a codebook for 8 antenna ports. Mode 9 can be used in a base station that performs transmission at an antenna port. Therefore, the storage capacity of the mobile terminal can be reduced, and the processing of the mobile terminal can be reduced. Further, the base station can perform efficient scheduling and handover.

  Note that a program for realizing the functions of all or part of the base station apparatus or all or part of the terminal apparatus in each of the above embodiments is recorded on a computer-readable recording medium and recorded on this recording medium. Each unit may be processed by causing the computer system to read and execute the program. 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.

  The present invention can also be expressed as follows.

  (1) A terminal apparatus according to an aspect of the present invention is a terminal apparatus that communicates with a base station apparatus having a precoder defined by a plurality of codebooks, and the terminal apparatus supports from among the plurality of codebooks. Information indicating a code book is notified to the base station apparatus. Thereby, the base station can perform efficient scheduling and handover using the notified information.

  (2) In addition, a terminal device according to an aspect of the present invention is the terminal device described above, and explicitly notifies the base station device of information indicating a codebook supported by the terminal device. And Thereby, the storage capacity of the terminal device that supports only a small number of codebooks can be reduced, and the processing of the terminal device can be reduced.

  (3) A terminal device according to an aspect of the present invention is the terminal device described above, and implicitly notifies the base station device of information indicating a codebook supported by the terminal device. And Thereby, the storage capacity of the terminal device that supports only a small number of codebooks can be reduced, and the processing of the terminal device can be reduced.

  (4) Moreover, the terminal device according to an aspect of the present invention is the terminal device described above, and the terminal device capability information indicating the communication capability of the terminal device includes information indicating a codebook supported by the terminal device, A notification is made to the base station apparatus. As a result, the code book supported by the terminal device can be notified efficiently.

  (5) A base station apparatus according to an aspect of the present invention is a base station apparatus in a communication system that communicates between a base station apparatus having a precoder defined by a plurality of codebooks and a terminal apparatus, The transmission mode is determined based on information indicating a codebook supported by the terminal device from the plurality of codebooks notified from the terminal device. Thereby, the base station can determine an efficient transmission mode.

  (6) A communication system according to an aspect of the present invention is a communication system that performs communication between a base station apparatus having a precoder defined by a plurality of codebooks and a terminal apparatus, and the terminal apparatus includes Information indicating a codebook supported by the terminal apparatus from among a plurality of codebooks is notified to the base station apparatus, and the base station apparatus determines a transmission mode based on the information. And Thereby, the base station can determine an efficient transmission mode.

  (7) A communication method according to an aspect of the present invention is a communication method of a terminal apparatus that communicates with a base station apparatus having a precoder defined by a plurality of codebooks, and the communication method is the above-mentioned among the plurality of codebooks. The method includes a step of notifying the base station device of information indicating a code book supported by the terminal device. Thereby, the base station can perform efficient scheduling and handover using the notified information.

  (8) A communication method according to an aspect of the present invention is a communication method of a base station apparatus in a communication system that performs communication between a base station apparatus having a precoder defined by a plurality of codebooks and a terminal apparatus. And determining a transmission mode based on information indicating a codebook supported by the terminal device from the plurality of codebooks notified from the terminal device. Thereby, the base station can determine an efficient transmission mode.

  (9) A communication method according to an aspect of the present invention is a communication method for a communication system that performs communication between a base station apparatus having a precoder defined by a plurality of codebooks and a terminal apparatus, and the terminal apparatus Includes notifying the base station apparatus of information indicating a code book supported by the terminal apparatus from the plurality of code books, and the base station apparatus transmits a transmission mode based on the information. Is included. Thereby, the base station can determine an efficient transmission mode.

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

DESCRIPTION OF SYMBOLS 1100 ... Base station 1101 ... Adaptive control part 1102 ... Multiplexer 1103 ... Transmission antenna 1104 ... Reception antenna 1105 ... Feedback information processing part 1110 ... Mobile terminal 1111 ... Reception antenna 1112 ... Separation part 1113 ... Feedback information generation part 1114 ... Transmission antenna 1201 ... Base station 1202 ... Mobile terminal 1203 ... Mobile terminal capability inquiry 1204 ... Mobile terminal capability information

Claims (18)

A terminal device that communicates with a base station device,
A terminal apparatus that notifies the base station apparatus of information indicating whether the terminal apparatus supports a transmission mode that uses a transmission channel state measurement reference signal of eight antenna ports.   2. The terminal device according to claim 1, wherein the information is “1” indicating that the terminal device supports a transmission mode using a transmission path condition measurement reference signal of 8 antenna ports.   2. The terminal device according to claim 1, wherein the information is “0” indicating that the terminal device does not support a transmission mode using an 8-antenna port transmission path condition measurement reference signal.   The terminal device according to claim 1, wherein the information is notified using terminal capability information indicating the capability of the terminal device.   The terminal apparatus according to claim 1, wherein the transmission mode is a transmission method in which an information data signal is transmitted at a maximum of 8 layers.   The terminal device according to claim 1, wherein a terminal device that can switch and notify the information is determined according to a terminal category of the terminal device. A terminal device that communicates with a base station device,
A terminal apparatus that notifies the base station apparatus of “1” indicating that the terminal apparatus has a transmission mode function that uses a transmission path condition measurement reference signal of 8 antenna ports. A terminal device that communicates with a base station device,
A terminal apparatus that notifies the base station apparatus of “0” indicating that the terminal apparatus does not have a function of a transmission mode that uses a transmission path condition measurement reference signal of 8 antenna ports. A base station device that communicates with a terminal device,
A base station apparatus that is notified from the terminal apparatus of information indicating whether or not the terminal apparatus supports a transmission mode that uses a transmission channel state measurement reference signal of eight antenna ports.   The information is “1” indicating that the terminal apparatus supports a transmission mode using a reference signal for transmission path condition measurement of 8 antenna ports, or the terminal apparatus is for transmission path condition measurement of 8 antenna ports. The base station apparatus according to claim 9, which is “0” indicating that a transmission mode using a reference signal is not supported.   The base station apparatus according to claim 9, wherein the information is notified using terminal capability information indicating a capability of the terminal apparatus.   The base station apparatus according to claim 9, wherein the transmission mode is a transmission method in which an information data signal is transmitted at a maximum of 8 layers.   The base station apparatus according to claim 9, wherein a terminal apparatus that can switch and notify the information is determined according to a terminal category of the terminal apparatus. A base station device that communicates with a terminal device,
“0” indicating that the terminal device does not have the function, or the function as information indicating whether the terminal device has a function of a transmission mode using a transmission path condition measurement reference signal of 8 antenna ports The base station apparatus is notified from the terminal apparatus of “1” indicating that A communication method of a terminal device that communicates with a base station device,
A communication method of notifying the base station apparatus of information indicating whether the terminal apparatus supports a transmission mode using a transmission path condition measurement reference signal of 8 antenna ports. A communication method of a base station device that communicates with a terminal device,
A communication method in which the terminal device is notified of information indicating whether the terminal device supports a transmission mode that uses a transmission channel state measurement reference signal of eight antenna ports. An integrated circuit realized by a terminal device communicating with a base station device,
An integrated circuit that notifies the base station apparatus of information indicating whether the terminal apparatus supports a transmission mode that uses a transmission path condition measurement reference signal of an 8-antenna port. An integrated circuit realized by a base station device communicating with a terminal device,
An integrated circuit in which the terminal device is notified of information indicating whether the terminal device supports a transmission mode that uses a transmission channel state measurement reference signal of eight antenna ports.