JP2013034047A - Mobile communication system, base station device, mobile station device, and communication method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mobile communication system, a base station device, a mobile station device, and a communication method which can obtain a better performance gain for the mobile station device under a high-mobility case.SOLUTION: In a mobile communication system, a base station device schedules a physical uplink shared channel by use of a downlink control information format. The base station device selectively sets a first value or a second value to the downlink control information format and transmits the set downlink control information format. A mobile station device transmits the physical uplink shared channel by means of four antenna ports if the first value is set and by means of two antenna ports if the second value is set.

Description

  The present invention relates to a mobile communication system, a base station apparatus, a mobile station apparatus, and a communication method.

  The evolution of cellular mobile radio access systems and wireless networks (hereinafter LTE: Long Term Evolution or EUTRA: Evolved Universal Terrestrial Radio Access) is being developed in the 3rd Generation Partnership Project (3GPP). It is being considered. In LTE, an OFDM (Orthogonal Frequency Division Multiplexing) scheme is used as a downlink communication scheme from a base station apparatus to a mobile station apparatus. Further, as an uplink communication system from the mobile station apparatus to the base station apparatus, an SC-FDMA (Single-Carrier Frequency Division Multiple Access) system excellent in PAPR (Peak to Average Power Ratio) characteristics is used. Here, in LTE, a base station apparatus is also called eNodeB (evolved NodeB) and a mobile station apparatus is also called UE (User Equipment).

  In LTE Release 11, it is considered to use spatial multiplexing (also called Spatial Multiplexing, also referred to as MIMO SM) by MIMO (Multiple Input Multiple Output) in the uplink. Here, MIMO SM is a technique that is realized by a plurality of transmission / reception antenna ports, and that a plurality of signal sequences (also referred to as layers and streams) are spatially multiplexed and transmitted / received. . In addition, the number of spatially multiplexed signal sequences (also referred to as the number of layers, the number of streams, and the number of spatially multiplexed sequences) is also referred to as rank.

  An antenna port indicates a logical antenna port used for signal processing. That is, one antenna port may correspond to one physical antenna or may correspond to a plurality of physical antennas. That is, the number of antenna ports is defined as the same or less than the number of physical antennas. That is, an antenna port is defined for each physical antenna or by combining two or more physical antennas.

  Furthermore, on the transmission side (for example, the mobile station apparatus side) when performing communication using MIMO SM, precoding (precoding matrix) is applied to a plurality of signal sequences in order to form an appropriate spatial channel. The plurality of precoded signal sequences are transmitted using a plurality of antenna ports (mapped to a plurality of antenna ports). That is, in order to correctly separate information of a plurality of signal sequences transmitted using a plurality of antenna ports, precoding is performed on the signal sequences in advance, and the plurality of precoded signals are converted to a plurality of antenna ports. Send using.

  Here, regarding transmission using MIMO SM in the uplink, in order to obtain a better performance gain for a mobile station apparatus under a high mobility case, a MIMO scheme that does not depend on a channel (also referred to as a propagation path) (A channel independent MIMO scheme) has been proposed (Non-Patent Document 1).

"UL MIMO Proposed Enhancements in Rel-11", 3GPP TSG RAN WG1 Meeting # 65, R1-111478, May 9-13, 2011.

  However, in the prior art, there is no specific description of how the base station apparatus instructs the mobile station apparatus on information related to transmission at a plurality of antenna ports.

  Here, for example, the information related to transmission at a plurality of antenna ports includes the number of transmission ranks used when the mobile station apparatus performs transmission at a plurality of antenna ports. Further, for example, the information regarding transmission at a plurality of antenna ports includes a codebook index (precoding matrix) used when the mobile station apparatus performs transmission at a plurality of antenna ports. Further, for example, the information related to transmission using a plurality of antenna ports includes the number of antenna ports used when the mobile station apparatus performs transmission using a plurality of antenna ports.

  Here, in order to obtain a better performance gain for a mobile station device under a high mobility case, the base station device dynamically (information dynamically, for example, information related to transmission at a plurality of antenna ports). It is desirable to be able to instruct (switch) every 1 ms.

  The present invention has been made in view of such circumstances, and a mobile communication system, a base station apparatus, and a mobile station apparatus that can obtain better performance gain for a mobile station apparatus under a high mobility case And providing a communication method.

  (1) In order to achieve the above object, the present invention takes the following measures. That is, the mobile communication system of the present invention is a mobile communication system in which a base station apparatus schedules a physical uplink shared channel to a mobile station apparatus using a downlink control information format, and the base station apparatus The first value or the second value is selectively set in the information field included in the downlink control information format and transmitted to the mobile station apparatus, and the mobile station apparatus transmits the first value in the information field. When the value of is set, the physical uplink shared channel is transmitted to the base station apparatus using four antenna ports, and when the second value is set in the information field, The physical uplink shared channel is transmitted to the base station apparatus using two antenna ports, and the information field is shared with the physical uplink. It is characterized by being used to indicate the transmission number of layers and codebook indices for Yaneru.

  (2) The number of transmission layers when the mobile station apparatus transmits the physical uplink shared channel using the two antenna ports is two.

  (3) In addition, the codebook index when the mobile station apparatus transmits the physical uplink shared channel using the two antenna ports corresponds to 1 / √2 [1, 0; 0, 1]. It is characterized by.

  (4) A base station apparatus that schedules a physical uplink shared channel for a mobile station apparatus using a downlink control information format, wherein a first field is included in an information field included in the downlink control information format. A unit that selectively sets a value or a second value to transmit to the mobile station apparatus, and when the first value is set in the information field, the mobile station apparatus sets four antenna ports. When the second value is set in the information field, the unit that receives the physical uplink shared channel transmitted using the mobile station apparatus transmits the antenna using the two antenna ports. A unit that receives a physical uplink shared channel, and the information field includes the physical uplink shared channel. It is characterized by being used to indicate the transmission number of layers and codebook indices for.

  (5) The number of transmission layers when the mobile station apparatus transmits the physical uplink shared channel using the two antenna ports is two.

  (6) The codebook index when the mobile station apparatus transmits the physical uplink shared channel using the two antenna ports corresponds to 1 / √2 [1, 0; 0, 1]. It is characterized by.

  (7) Further, the mobile station apparatus schedules the physical uplink shared channel by the base station apparatus using the downlink control information format, and the base station apparatus selects the first value or the second value. A unit that receives the downlink control information format including the set information field from the base station apparatus, and when the first value is set in the information field, four antenna ports are used. A unit for transmitting the physical uplink shared channel to the base station apparatus, and when the second value is set in the information field, the physical uplink shared channel is transmitted using two antenna ports. A unit for transmitting to a base station device, wherein the information field is in the physical uplink shared channel. It is characterized by being used to indicate the transmission number of layers and codebook index.

  (8) In addition, the number of transmission layers when transmitting the physical uplink shared channel using the two antenna ports is two.

  (9) The codebook index when transmitting the physical uplink shared channel using the two antenna ports corresponds to 1 / √2 [1, 0; 0, 1].

  (10) A communication method of a base station apparatus that schedules a physical uplink shared channel to a mobile station apparatus using a downlink control information format, the information field included in the downlink control information format When the first value or the second value is selectively set and transmitted to the mobile station apparatus, and the first value is set in the information field, the mobile station apparatus sets four antenna ports. And when the second value is set in the information field, the physical station transmitted using the two antenna ports is received by the mobile station apparatus. An uplink shared channel is received, and the information field includes the number of transmission layers and the code for the physical uplink shared channel. It is characterized by being used to indicate the book index.

  (11) Further, the number of transmission layers when the mobile station apparatus transmits the physical uplink shared channel using the two antenna ports is two.

  (12) The codebook index when the mobile station apparatus transmits the physical uplink shared channel using the two antenna ports corresponds to 1 / √2 [1, 0; 0, 1]. It is characterized by.

  (13) Further, there is provided a communication method for a mobile station apparatus, in which a physical uplink shared channel is scheduled by a base station apparatus using a downlink control information format, wherein a first value or a second value is determined by the base station apparatus. When the downlink control information format including an information field in which a value is selectively set is received from the base station apparatus, and the first value is set in the information field, four antenna ports are set. The physical uplink shared channel is transmitted to the base station apparatus, and when the second value is set in the information field, the physical uplink shared channel is transmitted to the base station using two antenna ports. The information field includes the number of transmission layers and the code block for the physical uplink shared channel. It is characterized by being used to indicate a click index.

  (14) Further, the number of transmission layers when transmitting the physical uplink shared channel using the two antenna ports is two.

  (15) The codebook index when transmitting the physical uplink shared channel using the two antenna ports corresponds to 1 / √2 [1, 0; 0, 1].

  Provided are a mobile communication system, a base station apparatus, a mobile station apparatus and a communication method capable of obtaining a better performance gain for a mobile station apparatus under a high mobility case.

It is a figure which shows notionally the structure of the physical channel which concerns on embodiment of this invention. It is a block diagram which shows schematic structure of the base station apparatus which concerns on embodiment of this invention. It is a block diagram which shows schematic structure of the mobile station apparatus which concerns on embodiment of this invention. It is a figure which shows the example of an uplink transmission mode. It is a figure which shows the example of the code book with respect to transmission in 2 antenna ports. It is a figure which shows the example of the code book with respect to transmission with 4 antenna ports in case the number of transmission layers is "1". It is a figure which shows the example of the code book with respect to transmission with 4 antenna ports in case the number of transmission layers is "2". It is a figure which shows the example of the code book with respect to transmission with 4 antenna ports in case the number of transmission layers is "3". It is a figure which shows the example of the code book with respect to transmission by 4 antenna ports in case the number of transmission layers is "4". It is a figure which shows the example of the content of the precoding information field.

  Next, embodiments according to the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a configuration example of a physical channel in the embodiment of the present invention. Here, the physical channel is defined (configured) by a time domain and a frequency domain.

  As shown in FIG. 1, downlink physical channels include a physical downlink control channel (PDCCH), a physical downlink shared channel (PDSCH), and the like. The uplink physical channel includes a physical uplink shared channel (PUSCH), a physical uplink control channel (PUCCH), and the like.

  Here, the PDCCH is downlink control information (DCI) such as downlink scheduling information (also referred to as downlink assignment) and uplink scheduling information (also referred to as uplink grant). : Downlink Control Information) is a physical channel used to transmit (notify, specify). A plurality of formats are defined for transmission of downlink control information. Here, the format of the downlink control information is also referred to as a DCI format (Downlink Control Information format).

  For example, DCI format 1 is used for scheduling of PDSCH (which may be one PDSCH codeword (CW)) in one downlink cell. DCI format 2 is used for scheduling of PDSCH in one downlink cell in the multi-antenna port mode. That is, DCI format 1 and DCI format 2 are downlink assignments used for PDSCH scheduling.

  That is, for example, in DCI format 1 and DCI format 2, resource allocation information for PDSCH (Resource block assignment), information on modulation scheme and coding rate for PDSCH (downlink transport block transmitted on PDSCH) (MCS: Information fields such as Modulation and Coding Scheme (fields mapped to information bits, also called bit fields) are defined.

  Also, for example, DCI format 0 is used for PUSCH scheduling in one uplink cell (in single antenna port transmission mode). DCI format 4 is used for PUSCH scheduling in one uplink cell in the multi-antenna port mode. That is, DCI format 0 and DCI format 4 are uplink grants used for PUSCH scheduling.

  That is, for example, in DCI format 0, resource allocation information for PUSCH (Resource block assignment), information on modulation scheme and coding rate for PUSCH (uplink transport block transmitted on PUSCH) (MCS: Modulation and Coding Scheme) ) And other information fields are defined.

  Further, for example, in DCI format 4, resource allocation information for PUSCH (Resource block assignment), information on modulation scheme and coding rate for uplink transport block 1 transmitted on PUSCH (MCS: Modulation and Coding Scheme), Information fields such as information on modulation scheme and coding rate (MCS: Modulation and Coding Scheme) for the uplink transport block 2 transmitted on the PUSCH are defined.

  For example, in DCI format 4, information fields of precoding information and information (Precoding information and number of layers) indicating the number of layers (number of transmission layers) are defined. Hereinafter, precoding information and information indicating the number of layers are also simply referred to as precoding information. An information field defined as information indicating precoding information and the number of layers is also referred to as a precoding information field. That is, a codebook index (precoding matrix) is indicated according to a value (which may be an information bit) set in the precoding information field. Further, the number of transmission layers is indicated according to a value (information bit may be set) set in precoding information.

  Here, for example, precoding information (precoding information field) is represented by 3 bits of information bits when the number of antenna ports in the mobile station apparatus is 2. For example, precoding information (precoding information field) is represented by 6 information bits when the number of antenna ports in the mobile station apparatus is 4.

  In addition, the PDSCH transmits downlink data (a transport block for a downlink shared channel (DL-SCH)) or paging information (a transport block for a paging channel (PCH)). The channel used. The base station apparatus transmits downlink data to the mobile station apparatus using the PDSCH assigned by the PDCCH.

  Here, the downlink data indicates, for example, user data, and DL-SCH is a transport channel. Here, the downlink transport block is a unit handled in a MAC (Medium Access Control) layer. Also, the downlink transport block is associated with a codeword in the physical layer. That is, the downlink transport block is a unit of data supplied (delivered) from the MAC layer to the physical layer.

  Furthermore, PUSCH is a physical channel used for transmitting uplink data (transport block for uplink shared channel (UL-SCH)). A mobile station apparatus transmits uplink data to a base station apparatus using PUSCH allocated by PDCCH transmitted from the base station apparatus.

  Here, the uplink data indicates, for example, user data, and UL-SCH is a transport channel. Here, the uplink transport block is a unit handled in the MAC layer. Further, the uplink transport block is associated with a codeword in the physical layer. That is, the uplink transport block is a unit of data supplied from the MAC layer to the physical layer.

  Further, the base station device and the mobile station device exchange (transmit / receive) signals in the higher layer. For example, the base station device and the mobile station device transmit and receive a radio resource control signal (hereinafter also referred to as RRC signaling: Radio Resource Control Signaling) in a radio resource control (RRC) layer.

  Here, in the RRC layer, a dedicated signal (a dedicated signal for a certain mobile station apparatus) transmitted to a certain mobile station apparatus by the base station apparatus is also referred to as dedicated signaling. Further, the base station device and the mobile station device transmit and receive MAC control elements in a MAC (Medium Access Control) layer. Here, the RRC signaling and / or MAC control element is also referred to as higher layer signaling.

  Moreover, PUCCH is a physical channel used in order to transmit uplink control information (UCI: Uplink Control Information). Here, the uplink control information includes downlink channel state information (CSI). The uplink control information includes information indicating ACK / NACK (Positive Acknowledgement / Negative Acknowledgement) for downlink data.

[Configuration of base station apparatus]
FIG. 2 is a block diagram showing a schematic configuration of the base station apparatus 100 according to the embodiment of the present invention. The base station apparatus 100 includes a data control unit 101, a transmission data modulation unit 102, a radio unit 103, a scheduling unit 104, a channel estimation unit 105, a received data demodulation unit 106, a data extraction unit 107, and an upper layer. 108 and an antenna 109. The radio unit 103, the scheduling unit 104, the channel estimation unit 105, the reception data demodulation unit 106, the data extraction unit 107, the upper layer 108 and the antenna 109 constitute a reception unit, and the data control unit 101, the transmission data modulation unit 102, The radio unit 103, the scheduling unit 104, the upper layer 108, and the antenna 109 constitute a transmission unit. Here, each part which comprises the base station apparatus 100 is also called a unit.

  The antenna 109, the radio unit 103, the channel estimation unit 105, the reception data demodulation unit 106, and the data extraction unit 107 perform processing on the uplink physical layer. The antenna 109, the radio unit 103, the transmission data modulation unit 102, and the data control unit 101 perform downlink physical layer processing.

  The data control unit 101 receives a transport channel from the scheduling unit 104. The data control unit 101 maps the transport channel and the signal and channel generated in the physical layer to the physical channel based on the scheduling information input from the scheduling unit 104. Each piece of data mapped as described above is output to transmission data modulation section 102.

  The transmission data modulation unit 102 modulates transmission data to the OFDM scheme. The transmission data modulation unit 102 applies the scheduling information from the scheduling unit 104 to the data input from the data control unit 101 and the modulation scheme and coding scheme corresponding to each physical resource block (PRB). Based on this, it performs signal processing such as coding, serial / parallel conversion of input signals, IFFT (Inverse Fast Fourier Transform) processing, CP (Cyclic Prefix) insertion, and filtering to generate transmission data. To the wireless unit 103.

  Here, the scheduling information includes PRB allocation information, for example, PRB position information composed of frequency and time, and the modulation scheme and coding scheme corresponding to each PRB include, for example, modulation scheme: 16QAM, Encoding rate: Information such as 2/3 coding rate is included.

  Radio section 103 up-converts the modulation data input from transmission data modulation section 102 to a radio frequency to generate a radio signal, and transmits the radio signal to mobile station apparatus 200 via antenna 109. Radio section 103 receives an uplink radio signal from mobile station apparatus 200 via antenna 109, down-converts it into a baseband signal, and receives received data as channel estimation section 105 and received data demodulation section 106. And output.

  The scheduling unit 104 performs MAC layer processing. The scheduling unit 104 performs mapping between logical channels and transport channels, downlink and uplink scheduling (HARQ processing, selection of transport format, etc.), and the like. Since the scheduling unit 104 controls the processing units of each physical layer in an integrated manner, the scheduling unit 104, the antenna 109, the radio unit 103, the channel estimation unit 105, the reception data demodulation unit 106, the data control unit 101, the transmission data modulation An interface between the unit 102 and the data extraction unit 107 exists.

  In downlink scheduling, the scheduling unit 104 performs uplink control information received from the mobile station apparatus 200, PRB information usable in each mobile station apparatus 200, buffer status, and scheduling input from the upper layer 108. Based on information, etc., it is used for downlink transport format (transmission form, ie, PRB allocation, modulation scheme and coding scheme) selection processing for modulation of each data, HARQ retransmission control and downlink Scheduling information is generated. The scheduling information used for downlink scheduling is output to the data control unit 101.

  Further, in uplink scheduling, the scheduling unit 104 estimates the uplink channel state (radio channel state) output from the channel estimation unit 105, the resource allocation request from the mobile station device 200, and each mobile station device 200. Uplink transport format for modulating each data based on the PRB information that can be used in the network, scheduling information input from the higher layer 108, etc. (transmission form, ie, PRB allocation, modulation scheme and encoding) The scheduling information used for the selection process of the method and the scheduling of the uplink is generated. Scheduling information used for uplink scheduling is output to the data control unit 101.

  In addition, the scheduling unit 104 maps the downlink logical channel input from the higher layer 108 to the transport channel, and outputs it to the data control unit 101. In addition, the scheduling unit 104 processes the control data and the transport channel acquired in the uplink input from the data extraction unit 107 as necessary, maps them to the uplink logical channel, and outputs them to the upper layer 108. To do.

  Channel estimation section 105 estimates an uplink channel state from an uplink demodulation reference signal (UDRS) for demodulation of uplink data, and outputs the estimation result to reception data demodulation section 106. To do. In addition, in order to perform uplink scheduling, an uplink channel state is estimated from an uplink measurement reference signal (SRS), and the estimation result is output to the scheduling section 104.

  The reception data demodulator 106 also serves as an OFDM demodulator and / or a DFT-Spread-OFDM (DFT-S-OFDM) demodulator that demodulates received data modulated by the OFDM scheme and / or SC-FDMA scheme. Based on the uplink channel state estimation result input from the channel estimation unit 105, the reception data demodulation unit 106 performs DFT conversion, subcarrier mapping, IFFT conversion, filtering, and the like on the modulation data input from the radio unit 103. Are subjected to demodulation processing and output to the data extraction unit 107.

  The data extraction unit 107 confirms whether the data input from the reception data demodulation unit 106 is correct and outputs a confirmation result (ACK or NACK) to the scheduling unit 104. The data extraction unit 107 separates the data input from the reception data demodulation unit 106 into a transport channel and physical layer control data, and outputs the data to the scheduling unit 104. The separated control data includes CSI and HARQ control information transmitted from the mobile station apparatus 200, a scheduling request, and the like.

  The upper layer 108 performs processing of a packet data convergence protocol (PDCP) layer, a radio link control (RLC) layer, and a radio resource control (RRC) layer. The upper layer 108 integrates and controls the processing units of the lower layer, so the upper layer 108, the scheduling unit 104, the antenna 109, the radio unit 103, the channel estimation unit 105, the received data demodulation unit 106, the data control unit 101, There is an interface between the transmission data modulation unit 102 and the data extraction unit 107.

  The upper layer 108 has a radio resource control unit 110 (also referred to as a control unit). The radio resource control unit 110 also manages various setting information, system information, paging control, communication state management of each mobile station device 200, mobility management such as handover, and buffer status for each mobile station device 200. Management, management of unicast and multicast bearer connection settings, management of mobile station identifiers (UEID), and the like. Upper layer 108 exchanges information with another base station apparatus 100 and information with an upper node.

[Configuration of mobile station device]
FIG. 3 is a block diagram showing a schematic configuration of the mobile station apparatus 200 according to the embodiment of the present invention. The mobile station apparatus 200 includes a data control unit 201, a transmission data modulation unit 202, a radio unit 203, a scheduling unit 204, a channel estimation unit 205, a reception data demodulation unit 206, a data extraction unit 207, and an upper layer. 208 and an antenna 209. The data control unit 201, transmission data modulation unit 202, radio unit 203, scheduling unit 204, higher layer 208, and antenna 209 constitute a transmission unit, and the radio unit 203, scheduling unit 204, channel estimation unit 205, received data demodulation unit Unit 206, data extraction unit 207, upper layer 208, and antenna 209 constitute a reception unit. Here, each part which comprises the mobile station apparatus 200 is also called a unit.

  The data control unit 201, the transmission data modulation unit 202, and the radio unit 203 perform processing on the uplink physical layer. The radio unit 203, the channel estimation unit 205, the received data demodulation unit 206, and the data extraction unit 207 perform downlink physical layer processing.

  The data control unit 201 receives a transport channel from the scheduling unit 204. The transport channel and the signal and channel generated in the physical layer are mapped to the physical channel based on the scheduling information input from the scheduling unit 204. Each piece of data mapped in this way is output to transmission data modulation section 202.

  The transmission data modulation unit 202 modulates transmission data into the OFDM scheme and / or the SC-FDMA scheme. The transmission data modulation unit 202 performs data modulation, DFT (Discrete Fourier Transform) processing, subcarrier mapping, IFFT (Inverse Fast Fourier Transform) processing, CP insertion, filtering, and other signals on the data input from the data control unit 201. Processing is performed, transmission data is generated, and output to the wireless unit 203.

  Radio section 203 up-converts the modulation data input from transmission data modulation section 202 to a radio frequency, generates a radio signal, and transmits the radio signal to base station apparatus 100 via antenna 209. Radio section 203 receives a radio signal modulated with downlink data from base station apparatus 100 via antenna 209, down-converts it to a baseband signal, and receives the received data as channel estimation section 205. And output to the received data demodulation section 206.

  The scheduling unit 204 performs MAC layer processing. The scheduling unit 104 performs mapping between logical channels and transport channels, downlink and uplink scheduling (HARQ processing, selection of transport format, etc.), and the like. Since the scheduling unit 204 controls the processing units of each physical layer in an integrated manner, the scheduling unit 204, the antenna 209, the data control unit 201, the transmission data modulation unit 202, the channel estimation unit 205, the reception data demodulation unit 206, the data There is an interface between the extraction unit 207 and the wireless unit 203.

  In downlink scheduling, the scheduling unit 204 controls reception of transport channels, physical signals, and physical channels based on scheduling information (transport format and HARQ retransmission information) from the base station apparatus 100 and the upper layer 208, and the like. Scheduling information used for HARQ retransmission control and downlink scheduling is generated. The scheduling information used for downlink scheduling is output to the data control unit 201.

  In uplink scheduling, the scheduling unit 204 receives the uplink buffer status input from the higher layer 208 and uplink scheduling information from the base station apparatus 100 input from the data extraction unit 207 (transport format and HARQ retransmission). Information), and scheduling processing for mapping the uplink logical channel input from the upper layer 208 to the transport channel and the uplink scheduling based on the scheduling information input from the upper layer 208, etc. Scheduling information to be generated is generated. Note that the information notified from the base station apparatus 100 is used for the uplink transport format. The scheduling information is output to the data control unit 201.

  Also, the scheduling unit 204 maps the uplink logical channel input from the higher layer 208 to the transport channel, and outputs it to the data control unit 201. The scheduling unit 204 also outputs the channel state information input from the channel estimation unit 205 and the CRC (Cyclic Redundancy Check) confirmation result input from the data extraction unit 207 to the data control unit 201. In addition, the scheduling unit 204 processes the control data and the transport channel acquired in the downlink input from the data extraction unit 207 as necessary, maps them to the downlink logical channel, and outputs them to the upper layer 208. To do.

  Channel estimation section 205 estimates the downlink channel state from the downlink reference signal and outputs the estimation result to reception data demodulation section 206 in order to demodulate the downlink data. Further, the channel estimation unit 205 estimates the downlink channel state from the downlink reference signal in order to notify the base station apparatus 100 of the estimation result of the downlink channel state, and uses this estimation result as channel state information. To the scheduling unit 204.

  Received data demodulation section 206 demodulates received data modulated by the OFDM method. Reception data demodulation section 206 performs demodulation processing on the modulated data input from radio section 203 based on the downlink channel state estimation result input from channel estimation section 205 and outputs the result to data extraction section 207. To do.

  The data extraction unit 207 performs CRC on the data input from the reception data demodulation unit 206 to confirm the correctness and outputs a confirmation result (information indicating ACK or NACK) to the scheduling unit 204. The data extraction unit 207 separates the data input from the reception data demodulation unit 206 into transport channel and physical layer control data, and outputs the data to the scheduling unit 204. The separated control data includes scheduling information such as downlink or uplink resource allocation and uplink HARQ control information.

  The upper layer 208 performs processing of a packet data convergence protocol (PDCP) layer, a radio link control (RLC) layer, and a radio resource control (RRC) layer. The upper layer 208 integrates and controls the processing units of the lower layer, so that the upper layer 208, the scheduling unit 204, the antenna 209, the data control unit 201, the transmission data modulation unit 202, the channel estimation unit 205, the reception data demodulation unit 206, an interface between the data extraction unit 207 and the wireless unit 203 exists.

  The upper layer 208 has a radio resource control unit 210 (also referred to as a control unit). The radio resource control unit 210 manages various setting information, system information, paging control, own station communication status, mobility management such as handover, buffer status management, unicast and multicast bearer connection setting. Management and management of mobile station identifier (UEID).

(First embodiment)
Next, a first embodiment in a mobile communication system using the base station apparatus 100 and the mobile station apparatus 200 will be described. In the first embodiment, the base station apparatus uses a first value (hereinafter also referred to as a value other than a predetermined value) or a second value (in the information field included in the DCI format used for PUSCH scheduling). (Hereinafter also referred to as a predetermined value) is selectively set and transmitted to the mobile station apparatus. When the first value is set in the information field, the mobile station apparatus uses four antenna ports. When the PUSCH is transmitted to the base station apparatus and the second value is set in the information field, the PUSCH is transmitted to the base station apparatus using two antenna ports. Here, the information field in which the first value or the second value is selectively set by the base station apparatus includes an information field used to indicate the number of transmission layers and the codebook index for the PUSCH.

  Further, the number of transmission layers when the mobile station apparatus transmits PUSCH using two antenna ports is two. Further, the codebook index when the mobile station apparatus transmits PUSCH using two antenna ports corresponds to 1 / √2 [1, 0; 0, 1]. That is, the transmission rank when the mobile station apparatus transmits PUSCH using two antenna ports is 2.

  Here, the information related to transmission at a plurality of antenna ports described below includes, for example, the number of transmission ranks used when the mobile station apparatus performs transmission at a plurality of antenna ports. Further, for example, the information regarding transmission at a plurality of antenna ports includes a codebook index (precoding matrix) used when the mobile station apparatus performs transmission at a plurality of antenna ports. Further, for example, the information related to transmission using a plurality of antenna ports includes the number of antenna ports used when the mobile station apparatus performs transmission using a plurality of antenna ports.

  FIG. 4 shows an uplink transmission mode set by the base station apparatus. That is, FIG. 4 shows PDCCH and PUSCH (PDCCH and PUSCH) set by C-RNTI (Cell-Radio Network Temporary Identifier, User-Equipment identity, also called mobile station apparatus identifier) instructed from the base station apparatus. Relevance). Here, for example, C-RNTI is used to identify a certain mobile station apparatus having an RRC connection (connected in the RRC layer) in a certain cell.

  In FIG. 4, the mobile station apparatus is set to transmit the PUSCH in a semi-statically manner via a higher layer signal (for example, dedicated signaling). Here, as described above, transmission of PUSCH (scheduling information for PUSCH) is instructed via PDCCH. That is, one of two uplink transmission modes indicated as mode 1 and mode 2 is set by the base station apparatus.

  Here, the mobile station apparatus transmits the corresponding PUSCH according to the PDCCH to be monitored (PDCCH to be decoded). That is, when the mobile station apparatus is set by the base station apparatus to decode a CRC (Cyclic Redundancy Check) PDCCH scrambled by C-RNTI, the mobile station apparatus sets the corresponding PUSCH according to the combination shown in FIG. Send.

  That is, the mobile station apparatus in which transmission mode 1 (also referred to as uplink transmission mode 1) is set by the base station apparatus is used in the common search area (common search space) and the mobile station apparatus specific (UE-specific search space). , DCI format 0 is monitored.

  In addition, the mobile station apparatus that has received (detected) the DCI format 0 transmitted by the base station apparatus performs PUSCH (hereinafter also referred to as an uplink transport block) in a single antenna port scheme in accordance with the downlink control information included in the DCI format 0. Good) to send.

  Furthermore, the mobile station apparatus in which the transmission mode 2 (also referred to as uplink transmission mode 2) is set by the base station apparatus monitors the DCI format 0 in the common search area and the mobile station apparatus, and is specific to the mobile station apparatus. DCI format 4 is monitored.

  Further, the mobile station apparatus that has received (detected) the DCI format 0 transmitted by the base station apparatus transmits the PUSCH by the single antenna port method according to the downlink control information included in the DCI format 0.

  That is, when the mobile station apparatus in which the transmission mode 2 is set by the base station apparatus receives the DCI format 0, the mobile station apparatus transmits (only) the PUSCH related to the uplink transport block 1, and the uplink transport block 2 does not transmit PUSCH related to 2. That is, when the mobile station apparatus in which the transmission mode 2 is set by the base station apparatus receives the DCI format 0, the mobile station apparatus assumes transmission of the PUSCH related to the uplink transport block 1 and performs uplink transport. Block 2 is invalidated.

  Here, each of the two uplink transport blocks transmitted by the mobile station apparatus using (one) PUSCH is also referred to as an uplink transport block 1 and an uplink transport block 2.

  In addition, the mobile station apparatus that has received (detected) the DCI format 4 transmitted by the base station apparatus transmits the PUSCH by the multi-antenna port method according to the downlink control information included in the DCI format 4. Here, the PUSCH transmission in the multi-antenna port scheme includes PUSCH transmission by closed-loop spatial multiplexing. In addition, PUSCH transmission in the multi-antenna port scheme includes PUSCH transmission by open-loop spatial multiplexing.

  That is, the mobile station apparatus whose transmission mode 2 is set by the base station apparatus can transmit no more than two uplink transport blocks. That is, the mobile station apparatus transmits one uplink transport block or two uplink transport blocks to the base station apparatus using (one) PUSCH (mapped to PUSCH).

  Here, when both the transport blocks of the uplink transport block 1 and the uplink transport block 2 are valid, the uplink transport block 1 becomes the code word 0, and the uplink transport block 2 becomes the code word. Mapped to 1. When the uplink transport block 1 is valid and the uplink transport block 2 is invalid, the uplink transport block 1 is mapped to the code word 0. Further, when the uplink transport block 1 is invalid and the uplink transport block 2 is valid, the uplink transport block 2 is mapped to the code word 0.

  Hereinafter, the case where the uplink transport block 1 is valid is also referred to as the code word 0 being valid. In addition, when the uplink transport block 1 is invalid, it is also described that the code word 0 is invalid. In addition, when the uplink transport block 2 is valid, the code word 1 is also valid. Furthermore, the case where the uplink transport block 2 is invalid is also described as the code word 2 being invalid.

  Here, for example, the base station apparatus includes information related to MCS included in the DCI format 4 to a predetermined value (for example, an index related to MCS is “0”), and resource allocation information to a predetermined value (for example, resource allocation information). Is set to a value larger than “1”), one uplink transport block can be invalidated.

  Further, for example, the base station apparatus sets information related to MCS included in the DCI format 4 to a predetermined value (for example, an index related to MCS is “28”), and resource allocation information to a predetermined value (for example, resource allocation information). One uplink transport block can be invalidated by setting it to “1”).

  Here, as shown in FIG. 4, when the base station apparatus is set to use two antenna ports for transmission mode 2, the mobile station apparatus performs transmission using the two antenna ports. That is, the mobile station apparatus transmits PUSCH using two antenna ports. Also, when the mobile station apparatus is set to use a 2 antenna port or a 4 antenna port for the transmission mode 2 by the base station apparatus, the mobile station apparatus transmits at the 2 antenna port or at the 4 antenna port. Send. That is, the mobile station apparatus transmits PUSCH using 2 antenna ports or 4 antenna ports. That is, the mobile station apparatus selectively performs transmission at the 2-antenna port and transmission at the 4-antenna port.

  For example, the mobile station apparatus performs transmission using two antenna ports as the default of transmission mode 2. Further, for example, when the transmission at the 4-antenna port is activated (activated) by the base station apparatus, the mobile station apparatus performs transmission at the 2-antenna port or transmission at the 4-antenna port. .

  For example, the base station apparatus transmits information for activating transmission at four antenna ports (for example, four antenna port activated) to the mobile station apparatus by including it in a higher layer signal. For example, the base station apparatus can set the activation of transmission at the four antenna ports to the mobile station apparatus in a cell-common manner. Also, the base station apparatus can set activation of transmission at the four antenna ports to the mobile station apparatus in a user station-dedicated manner. For example, the base station apparatus sets information for activating transmission at a 4-antenna port to the mobile station apparatus using dedicated signaling.

  In the following, a code book for transmission at the two antenna ports will be described. Here, as described above, the base station apparatus notifies (instructs) the codebook index to the mobile station apparatus using precoding information included in DCI format 4.

  FIG. 5 shows a codebook for transmission on a two antenna port. That is, FIG. 5 shows a precoding matrix used when the mobile station apparatus performs transmission at two antenna ports. Here, “υ” indicates the number of transmission layers.

  For example, in FIG. 5, the mobile station apparatus that is notified of the codebook index “0” by the base station apparatus and performs transmission with the transmission layer number “1” is the precoding matrix “1 / √2 [1; 1]”. ”(PUSCH transmission is performed with the number of transmission layers“ 1 ”using two antenna ports). Further, the mobile station apparatus that is notified of the codebook index “1” by the base station apparatus and performs transmission with the number of transmission layers “1” uses the precoding matrix “1 / √2 [1; −1]”. (PUSCH transmission is performed with the transmission layer number “1” using two antenna ports). Here, [A; B] indicates a 2 × 1 matrix.

  Further, the mobile station apparatus that is notified of the codebook index “0” by the base station apparatus and performs transmission with the transmission layer number “2” is the precoding matrix “1 / √2 [1, 0; 0, 1]. "Is used (PUSCH transmission with a transmission layer number" 2 "using two antenna ports is performed). Here, [A, B; C, D] indicates a 2 × 2 matrix.

  That is, a mobile station apparatus that performs PUSCH transmission with two antenna ports and the number of transmission layers “2” uses “1 / √2 [1, 0; 0, 1]” (hereinafter referred to as precoding matrix “W”) as a precoding matrix. ”). Here, the precoding matrix “1 / √2 [1, 0; 0, 1]” is a precoding matrix for indicating that transmission is performed with the number of transmission layers “2”. The precoding matrix “1 / √2 [1, 0; 0, 1]” can also be said to be a precoding matrix that does not depend on a channel.

  Here, as will be described later, the precoding matrix “W = 1 / √2 [1, 0; 0, 1]” is, for example, a mobile station apparatus that performs transmission using four antenna ports and the number of transmission layers “2”. May be used by. That is, by defining a precoding matrix “W = 1 / √2 [1, 0; 0, 1]” and a virtualization matrix “V”, transmission is performed with four antenna ports and the number of transmission layers “2”. It may be used by a mobile station device.

  FIG. 6 shows a codebook for transmission at four antenna ports when the number of transmission layers is “1”. That is, FIG. 6 shows a precoding matrix used when the mobile station apparatus performs transmission at four antenna ports with the transmission layer number “1”. Here, in FIG. 6, each column is ordered from left to right as the order of the codebook index increases.

  For example, in FIG. 6, the mobile station apparatus that is notified of the codebook index “0” by the base station apparatus and performs transmission with the transmission layer number “1” is the precoding matrix “1/2 [1; 1; 1]. −1] ”(PUSCH transmission is performed with the number of transmission layers“ 1 ”using four antenna ports). Further, the mobile station apparatus that is notified of the codebook index “1” by the base station apparatus and performs transmission with the transmission layer number “1” is the precoding matrix “1/2 [1; 1; j; j]”. (PUSCH transmission is performed with the number of transmission layers “1” using four antenna ports). Here, [A; B; C; D] represents a 4 × 1 matrix.

  FIG. 7 shows a codebook for transmission at a 4-antenna port when the number of transmission layers is “2”. That is, FIG. 7 shows a precoding matrix used when the mobile station apparatus performs transmission at four antenna ports in the number of transmission layers “2”. Here, in FIG. 7, each column is ordered from left to right as the order of the codebook index increases.

  For example, in FIG. 7, the mobile station apparatus that is notified of the codebook index “0” by the base station apparatus and performs transmission with the transmission layer number “2” is the precoding matrix “1/2 [1, 0; , 0; 0, 1; 0, −j] ”(PUSCH transmission is performed with the number of transmission layers“ 2 ”using four antenna ports). Also, the mobile station apparatus that is notified of the codebook index “1” by the base station apparatus and performs transmission with the number of transmission layers “2” is the precoding matrix “1/2 [1, 0; 1, 0; 1: 0, j] ”(PUSCH transmission is performed with the number of transmission layers“ 2 ”using four antenna ports). Here, [A, B; C, D; E, F; G, H] represents a 4 × 2 matrix.

  FIG. 8 shows a codebook for transmission with 4 antenna ports when the number of transmission layers is “3”. That is, FIG. 8 shows a precoding matrix used when the mobile station apparatus performs transmission at four antenna ports with the transmission layer number “3”. Here, in FIG. 8, each column is ordered from left to right as the order of the codebook index increases.

  For example, in FIG. 8, the mobile station apparatus that is notified of the codebook index “0” by the base station apparatus and performs transmission with the transmission layer number “3” is the precoding matrix “1/2 [1, 0, 0 , 1, 0, 0; 0, 1, 0; 0, 0, 1] ”(PUSCH transmission is performed with the number of transmission layers“ 3 ”using four antenna ports). Further, the mobile station apparatus that is notified of the codebook index “1” by the base station apparatus and performs transmission with the transmission layer number “3” is the precoding matrix “1/2 [1, 0, 0; −1, 0, 0; 0, 1, 0; 0, 0, 1] ”(PUSCH transmission is performed with the number of transmission layers“ 3 ”using four antenna ports). Here, [A, B, C; D, E, F; G, H, I; J, K, L] indicate a 4 × 3 matrix.

  FIG. 9 shows a codebook for transmission with 4 antenna ports when the number of transmission layers is “4”. That is, FIG. 9 shows a precoding matrix used when the mobile station apparatus performs transmission at four antenna ports with the transmission layer number “4”.

  For example, the mobile station apparatus that is notified of the codebook index “0” by the base station apparatus and performs transmission with the transmission layer number “4” is the precoding matrix “1/2 [1, 0, 0, 0; , 1, 0, 0; 0, 0, 1, 0; 0, 0, 0, 1] ”(PUSCH transmission is performed with the number of transmission layers“ 4 ”using four antenna ports). Here, [A, B, C, D; E, F, G, H; I, J, K, L; M, N, O, P] indicates a 4 × 4 matrix. That is, a mobile station apparatus that performs PUSCH transmission with the number of transmission layers “4” using four antenna ports is always precoding matrix “1/2 [1, 0, 0, 0; 0, 1, 0, 0. 0, 0, 1, 0; 0, 0, 0, 1] ".

  FIG. 10 shows the contents of the precoding information field when transmission at the 4-antenna port is activated by the base station apparatus. That is, FIG. 10 shows the contents of the precoding information field when information for activating transmission at four antenna ports is set by the base station apparatus (for example, when four antenna port activated is set). Is shown.

  As described above, the mobile station apparatus in which the activation of transmission at the 4-antenna port is set by the base station apparatus performs transmission at the 2-antenna port or transmission at the 4-antenna port. In addition, the base station apparatus notifies (instructs) the number of transmission layers and the codebook index to the mobile station apparatus using precoding information included in DCI format 4.

  For example, the base station apparatus specifies an index corresponding to the number of transmission layers and the codebook index as shown in FIG. 10 by setting information bits in the precoding information field. That is, a precoding information field (bit field) to which information bits are mapped is mapped to an index. Further, for example, the base station apparatus specifies an index corresponding to the number of antenna ports as shown in FIG. 10 by setting information bits in the precoding information field.

  The left side of FIG. 10 shows the contents of the precoding information field for one codeword (transmission of one codeword). That is, the left side of FIG. 10 shows the contents of the precoding information field when codeword 0 is valid and codeword 1 is invalid.

  Also, the right side of FIG. 10 shows the contents of the precoding information field for two codewords (transmission of two codewords). That is, the left side of FIG. 10 shows the contents of the precoding information field when codeword 0 is valid and codeword 1 is valid.

  For example, on the left side of FIG. 10, the mobile station apparatus that has received (detected) DCI format 4 in which the precoding information (information bits set in the precoding information field) indicates the index “0” Is transmitted using a precoding matrix (indicated by codebook index = “0”) corresponding to codebook index = “0”. At this time, the mobile station apparatus transmits PUSCH through the four antenna ports.

  That is, the mobile station apparatus transmits PUSCH using a precoding matrix corresponding to the number of transmission layers “1” and codebook index = “0” shown in FIG. That is, the mobile station apparatus transmits the PUSCH with the transmission layer number “1” using the precoding matrix “1/2 [1; 1; 1; −1]” (transmission layer using four antenna ports). (PUSCH transmission with “1” is performed).

  For example, on the left side of FIG. 10, the mobile station apparatus that has received the DCI format 4 whose precoding information indicates the index “25” transmits the transmission with the transmission layer number “2” to the codebook index = “1”. Do this using the corresponding precoding matrix. At this time, the mobile station apparatus transmits PUSCH through the four antenna ports.

  That is, the mobile station apparatus transmits PUSCH using a precoding matrix corresponding to the number of transmission layers “2” and codebook index = “1” shown in FIG. That is, the mobile station apparatus transmits the PUSCH with the number of transmission layers “2” using the precoding matrix “1/2 [1, 0; 1, 0; 0, 1; 0, j]” (4 PUSCH transmission is performed with the number of transmission layers “2” using the antenna port).

  Also, for example, on the right side of FIG. 10, the mobile station apparatus that has received the DCI format 4 whose precoding information indicates the index “17” transmits the transmission with the transmission layer number “3” to the codebook index = “1”. Do this using the corresponding precoding matrix. At this time, the mobile station apparatus transmits PUSCH through the four antenna ports.

  That is, the mobile station apparatus transmits PUSCH using a precoding matrix corresponding to the number of transmission layers “3” and codebook index = “1” shown in FIG. That is, the mobile station apparatus uses the precoding matrix “1/2 [1, 0, 0; −1, 0, 0; 0, 1, 0; 0, 0, 1]” to use the transmission layer number “ The PUSCH is transmitted at 3 ”(PUSCH transmission is performed at the transmission layer number“ 3 ”using 4 antenna ports).

  Further, for example, on the right side of FIG. 10, the mobile station apparatus that has received the DCI format 4 whose precoding information indicates the index “28” transmits the transmission with the number of transmission layers “4” to codebook index = “0”. Do this using the corresponding precoding matrix. At this time, the mobile station apparatus transmits PUSCH through the four antenna ports.

  That is, the mobile station apparatus transmits PUSCH using a precoding matrix corresponding to the number of transmission layers “4” and codebook index = “0” shown in FIG. That is, the mobile station apparatus uses a precoding matrix “1/2 [1, 0, 0, 0; 0, 1, 0, 0; 0, 0, 1, 0; 0, 0, 0, 1]”. Then, the PUSCH is transmitted with the transmission layer number “4” (PUSCH transmission is performed with the transmission layer number “4” using four antenna ports).

  Here, on the left side of FIG. 10, the mobile station apparatus that has received the DCI format 4 whose precoding information indicates the index “40” corresponds to the transmission with the number of transmission layers “2” corresponding to the codebook index = “0”. Do this using a precoding matrix. At this time, the mobile station apparatus performs PUSCH transmission on the two antenna ports.

  On the right side of FIG. 10, the mobile station apparatus that has received DCI format 4 whose precoding information indicates index “29” corresponds to codebook index = “0” for transmission with the number of transmission layers “2”. Do this using a precoding matrix. At this time, the mobile station apparatus performs PUSCH transmission on the two antenna ports.

  That is, the mobile station apparatus transmits PUSCH using a precoding matrix corresponding to the number of transmission layers “2” and codebook index = “0” shown in FIG. That is, the mobile station apparatus uses the precoding matrix “1 / √2 [1, 0; 0, 1]” to transmit the PUSCH with the transmission layer number “2” (transmission layer using two antenna ports). PUSCH transmission with the number “2” is performed).

  That is, an index corresponding to transmission at two antenna ports is defined in a table as shown in FIG. That is, an index corresponding to transmission with the number of transmission layers “2” using two antenna ports is defined in the table as shown in FIG. Here, the code corresponding to the transmission with the transmission layer number “2” using the two antenna ports is defined as an index corresponding to the transmission with the transmission layer number “2” using the two antenna ports. Also referred to as points being set.

  That is, a code point for transmission with the number of transmission layers “2” using two antenna ports is set in a table defining the number of transmission layers and codebook index for transmission with four antenna ports. That is, for example, the index “29” or the index “40” is also set as a code point for transmission with the transmission layer number “2” using two antenna ports.

  That is, the mobile station apparatus, when precoding information (information bits set in the precoding information field) indicates a predetermined value (for example, when an index indicates “40” or “29”). Performs transmission at the two antenna ports at the transmission layer number “2” (transmits at the transmission layer number “2” using the two antenna ports). At this time, the mobile station apparatus uses a precoding matrix (that is, “1 / √2 [1, 0; 0, 1]”) corresponding to transmission with two antenna ports and a transmission rank number “2”. To do.

  Here, as described above, the precoding information can indicate the number of transmission layers for transmission at the four antenna ports. In addition, the precoding information can indicate a codebook index (precoding matrix) for transmission at the 4-antenna port.

  That is, when the precoding information indicates a value other than a predetermined value, the mobile station apparatus performs transmission at the four antenna ports with the number of transmission layers according to the value. In addition, when the precoding information indicates a value other than a predetermined value, the mobile station apparatus performs transmission at the 4-antenna port with a codebook index according to the value.

  That is, the mobile station apparatus performs transmission at the two antenna ports only when the precoding information indicates a predetermined value. At this time, the mobile station apparatus performs transmission with the number of transmission layers “2”. That is, the mobile station apparatus uses “1 / √2 [1, 0; 0, 1]” as the precoding matrix.

  Here, for example, the predetermined value set in the precoding information is defined in advance by specifications or the like. That is, the predetermined value set in the precoding information can be known between the base station apparatus and the mobile station apparatus.

  Further, in this embodiment, in order to make the explanation easy to understand, an information field in which a predetermined value is set is described as a precoding information field. However, in the DCI format 4 as an information field in which a predetermined value is set. Other information fields defined may be used. That is, an information field in which a predetermined value is set may be defined in advance as a predetermined information field according to specifications or the like. That is, the predetermined information field in which the predetermined value is set can be known between the base station apparatus and the mobile station apparatus.

  That is, the mobile station apparatus activated by the base station apparatus for transmission at the 4-antenna port is based on whether a predetermined value is set in the precoding information field defined in the DCI format 4 or not. Or transmission on a 4-antenna port. That is, when a predetermined value is set in the precoding information field defined in the DCI format 4, the mobile station apparatus performs transmission at two antenna ports, and the precoding information field has a value other than the predetermined value. When the value is set, transmission is performed at the 4-antenna port.

  At this time, the mobile station apparatus that performs transmission using the two antenna ports performs transmission using the transmission rank number “2”. That is, the mobile station apparatus uses “1 / √2 [1, 0; 0, 1] as the precoding matrix. The mobile station apparatus that performs transmission at the four antenna ports is set in the precoding information field. The transmission is performed with the transmission rank and codebook index according to the determined value.

  That is, the number of layers for 4 antenna ports (transmission at 4 antenna ports) is indicated according to the value set in the precoding information field. Also, the codebook index (precoding matrix) for 4 antenna ports (transmission at 4 antenna ports) is indicated by the value set in the precoding information field. It can also be said that the number of antenna ports (transmission at two antenna ports or transmission at four antenna ports) is instructed according to the value set in the precoding information field.

  As explained above, when the precoding information included in the DCI format 4 indicates a value other than a predetermined value, the mobile station apparatus uses a plurality of antenna ports according to a value other than the predetermined value. When transmission is performed and the precoding information indicates a predetermined value, transmission is performed using two antenna ports and the number of transmission layers “2”, thereby performing transmission using a plurality of antenna ports. It is possible to dynamically indicate (switch) the information to be performed. That is, a better performance gain can be obtained for a mobile station apparatus under a high mobility case.

  In addition, it is not necessary to newly define an information field for instructing transmission in transmission with two antenna ports and the number of transmission layers “2”, and overhead when downlink control information is transmitted can be reduced. It becomes. That is, it is possible to instruct (switch) information used when performing transmission using a plurality of antenna ports by efficiently using radio resources.

  Here, the transmission (information transmission, signal transmission) processing applying the precoding matrix “W = 1 / √2 [1, 0; 0, 1]” independent of the channel described above is 2 Transmission at the antenna port can be performed without explicitly defining between the base station apparatus and the mobile station apparatus.

  That is, in the above description, since the precoding matrix “W = 1 / √2 [1, 0; 0, 1]” is a precoding matrix including two rows, the mobile station apparatus has two antennas. For example, a precoder “V * W” multiplied by a 4 × 2 antenna virtualization matrix “V” (hereinafter also referred to as a virtualization matrix) is described. By defining “”, the mobile station apparatus can obtain the same effect without performing transmission through the two antenna ports.

  That is, for example, the mobile station apparatus precoders “V * W” obtained by multiplying precoding matrix “W = 1 / √2 [1, 0; 0, 1]” and virtualization matrix “V” (in this case, Using precoder “V * W” can be said to be a precoding matrix), transmission at four antenna ports can be performed. That is, the mobile station apparatus performs pre-transmission at 4 antenna ports using precoding matrix “W = 1 / √2 [1, 0; 0, 1]” and virtualization matrix “V”. It is possible to obtain the same effect as that obtained when the transmission is performed at the two antenna ports using the recording matrix “W = 1 / √2 [1, 0; 0, 1]”.

  Here, the mobile station apparatus that performs transmission at the 4-antenna port using the precoding matrix “W = 1 / √2 [1, 0; 0, 1]” and the virtualization matrix “V” Transmission with “2” is performed (PUSCH transmission is performed with 4 antenna ports and the number of transmission layers used is “2”).

  Here, for example, the virtualization matrix “V” may be represented by a matrix for realizing CDD (Cyclic delay diversity). Further, for example, the virtualization matrix “V” may be represented by an antenna switch matrix that outputs a signal by selecting two antenna ports from four antenna ports. That is, a specific virtualization matrix “V” (value of “V”) does not need to have a common value between the base station apparatus and the mobile station apparatus (it does not need to be defined in advance by specifications or the like). ) And can be freely determined by the mobile station apparatus. That is, the specific virtualization matrix “V” depends on the implementation of the mobile station apparatus.

  Hereinafter, the operation when the mobile station apparatus performs transmission at the 4-antenna port using “V * W” as the precoding matrix will be described.

  As described above, in FIG. 4, when it is set to use two antenna ports for the transmission mode 2, the mobile station apparatus performs transmission using the two antenna ports. Here, in FIG. 4, when the transmission at the 4-antenna port is activated for the transmission mode 2, the mobile station apparatus performs (only) the transmission at the 4-antenna port (ie, the 2-antenna port). Will not be sent).

  That is, the base station apparatus includes information for activating transmission at the four antenna ports (for example, four Antenna Port Activated) in the upper layer signal and transmits the information to the mobile station apparatus. When information for activating transmission at the port is set, transmission (only) is performed at the 4-antenna port. That is, the mobile station apparatus transmits PUSCH using 4 antenna ports.

  Further, the base station apparatus sets a predetermined value in the precoding information included in DCI format 4 and notifies the mobile station apparatus. For example, as shown in FIG. 10, the base station apparatus transmits DCI format 4 whose precoding information indicates index “40” or index “29” to the mobile station apparatus.

  Here, when the precoding information indicates a predetermined value (for example, when the index indicates “40” or “29”), the mobile station apparatus uses four antennas with the transmission layer number “2”. Transmission at the port (transmission at the number of transmission layers “2” using four antenna ports). At this time, the mobile station apparatus uses the precoding matrix “V * W” for transmission with four antenna ports and “2” transmission layers. In other words, the mobile station apparatus uses the precoding matrix “W = 1 / √2 [1, 0; 0, 1]” and the virtualization matrix “V”, with 4 antenna ports and the number of transmission layers “2”. Send.

  That is, the mobile station apparatus uses the precoding matrix “W = 1 / √2 [1, 0; 0, 1]” only when the precoding information indicates a predetermined value. Send with. That is, the mobile station apparatus uses the precoding matrix “W = 1 / √2 [1, 0; 0, 1]” only when the precoding information indicates a predetermined value, Transmission with “2” is performed.

  That is, a mobile station apparatus that has received DCI format 4 including precoding information indicating a predetermined value does not necessarily use the precoding matrix “W = 1 / √2 [1, 0; 0, 1]”. It is not necessary to perform transmission using two antenna ports. That is, the mobile station apparatus that has received the DCI format 4 including precoding information indicating a predetermined value uses the precoding matrix “W” and the virtualization matrix “V” to provide 4 antenna ports and the number of transmission layers “2”. By performing "" transmission, it is possible to obtain the same effect as when performing transmission with two antenna ports and the number of transmission layers "2".

  That is, the mobile station apparatus activated by the base station apparatus for transmission at the 4-antenna port determines whether the precoding matrix is set based on whether a predetermined value is set in the precoding information field defined in DCI format 4. Transmission is performed at the 4-antenna port using “W = 1 / √2 [1, 0; 0, 1]”. That is, when a predetermined value is set in the precoding information field defined in DCI format 4, the mobile station apparatus precodes matrix “W = 1 / √2 [1, 0; 0, 1]. When a value other than a predetermined value is set in the precoding information field when transmission is performed on a 4-antenna port using "", a value other than the predetermined value is followed (a value other than the predetermined value is followed). Transmission is performed at 4 antenna ports (with the number of transmission layers and codebook index).

  As explained above, when the precoding information included in the DCI format 4 indicates a value other than a predetermined value, the mobile station apparatus uses a plurality of antenna ports according to a value other than the predetermined value. When transmission is performed and the precoding information indicates a predetermined value, by using the precoding matrix “V * W” and performing transmission with four antenna ports and the number of transmission layers “2”, Information used when performing transmission using a plurality of antenna ports can be dynamically instructed (switched). That is, a better performance gain can be obtained for a mobile station apparatus under a high mobility case.

  Also, a new information field for instructing transmission with 4 antenna ports and transmission layer number “2” using precoding matrix “W = 1 / √2 [1, 0; 0, 1]” is defined. It becomes unnecessary, and it becomes possible to reduce the overhead at the time of transmitting downlink control information. That is, it is possible to instruct (switch) information used when performing transmission using a plurality of antenna ports by efficiently using radio resources.

  The embodiment described above is also applied to an integrated circuit mounted on a base station device or a mobile station device. Further, in the embodiment described above, each function in the base station device and a program for realizing each function in the mobile station device are recorded on a computer-readable recording medium and recorded on this recording medium. The base station apparatus and the mobile station apparatus may be controlled by causing the computer system to read and execute the program. Here, the “computer system” includes an OS and hardware such as peripheral devices.

  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. Further, 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, it is also assumed that a server that holds a program for a certain time, such as a volatile memory inside a computer system that serves as a server or client. 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.

  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 the design and the like within the scope of the present invention are also within the scope of the claims. include.

100 base station apparatus 101 data control section 102 transmission data modulation section 103 radio section 104 scheduling section 105 channel estimation section 106 reception data demodulation section 107 data extraction section 108 upper layer 109 antenna 110 radio resource control section 200 mobile station apparatus 201 data control section 202 Transmission data modulation section 203 Radio section 204 Scheduling section 205 Channel estimation section 206 Reception data demodulation section 207 Data extraction section 208 Upper layer 209 Antenna 210 Radio resource control section

Claims (15)

A mobile communication system in which a base station device schedules a physical uplink shared channel to a mobile station device using a downlink control information format,
The base station device
A first value or a second value is selectively set in an information field included in the downlink control information format and transmitted to the mobile station apparatus;
The mobile station device
When the first value is set in the information field, the physical uplink shared channel is transmitted to the base station apparatus using four antenna ports,
When the second value is set in the information field, the physical uplink shared channel is transmitted to the base station apparatus using two antenna ports,
The mobile communication system, wherein the information field is used to indicate a number of transmission layers and a codebook index for the physical uplink shared channel. The mobile communication system according to claim 1, wherein the number of transmission layers when the mobile station device transmits the physical uplink shared channel using the two antenna ports is two. The codebook index when the mobile station apparatus transmits the physical uplink shared channel using the two antenna ports corresponds to 1 / √2 [1, 0; 0, 1]. The mobile communication system according to claim 1 or 2. A base station device that schedules a physical uplink shared channel to a mobile station device using a downlink control information format,
A unit that selectively sets a first value or a second value in an information field included in the downlink control information format and transmits the information to the mobile station apparatus;
When the first value is set in the information field, a unit that receives the physical uplink shared channel transmitted by the mobile station device using a four-antenna port;
A unit that receives the physical uplink shared channel transmitted by the mobile station device using two antenna ports when the second value is set in the information field;
The base station apparatus, wherein the information field is used to indicate a number of transmission layers and a codebook index for the physical uplink shared channel. The base station apparatus according to claim 4, wherein the number of transmission layers when the mobile station apparatus transmits the physical uplink shared channel using the two antenna ports is two. The codebook index when the mobile station apparatus transmits the physical uplink shared channel using the two antenna ports corresponds to 1 / √2 [1, 0; 0, 1]. Item 6. The base station apparatus according to Item 4 or Item 5. A mobile station device that schedules a physical uplink shared channel by a base station device using a downlink control information format,
A unit for receiving, from the base station apparatus, the downlink control information format including an information field in which a first value or a second value is selectively set by the base station apparatus;
When the first value is set in the information field, a unit that transmits the physical uplink shared channel to the base station device using a 4-antenna port;
A unit for transmitting the physical uplink shared channel to the base station device using two antenna ports when the second value is set in the information field;
The mobile station apparatus, wherein the information field is used to indicate a number of transmission layers and a codebook index for the physical uplink shared channel. The mobile station apparatus according to claim 7, wherein the number of transmission layers when transmitting the physical uplink shared channel using the two antenna ports is two. The codebook index when transmitting the physical uplink shared channel using the two antenna ports corresponds to 1 / √2 [1, 0; 0, 1]. The mobile station apparatus as described in. A communication method of a base station apparatus that schedules a physical uplink shared channel to a mobile station apparatus using a downlink control information format,
A first value or a second value is selectively set in an information field included in the downlink control information format and transmitted to the mobile station apparatus;
When the first value is set in the information field, the physical uplink shared channel transmitted by the mobile station apparatus using 4 antenna ports is received,
When the second value is set in the information field, the physical uplink shared channel transmitted by the mobile station device using two antenna ports is received,
The communication method, wherein the information field is used to indicate a number of transmission layers and a codebook index for the physical uplink shared channel. The communication method according to claim 10, wherein the number of transmission layers when the mobile station apparatus transmits the physical uplink shared channel using the two antenna ports is two. The codebook index when the mobile station apparatus transmits the physical uplink shared channel using the two antenna ports corresponds to 1 / √2 [1, 0; 0, 1]. Item 12. The communication method according to item 10 or item 11. A communication method of a mobile station apparatus, in which a physical uplink shared channel is scheduled by a base station apparatus using a downlink control information format,
Receiving the downlink control information format including the information field in which the first value or the second value is selectively set by the base station apparatus from the base station apparatus;
When the first value is set in the information field, the physical uplink shared channel is transmitted to the base station apparatus using four antenna ports,
When the second value is set in the information field, the physical uplink shared channel is transmitted to the base station apparatus using two antenna ports,
The communication method, wherein the information field is used to indicate a number of transmission layers and a codebook index for the physical uplink shared channel. The communication method according to claim 13, wherein the number of transmission layers when transmitting the physical uplink shared channel using the two antenna ports is two. The codebook index when transmitting the physical uplink shared channel using the two antenna ports corresponds to 1 / √2 [1, 0; 0, 1]. The communication method described in 1.