JP5469776B2 - Wireless communication system, base station apparatus, mobile station apparatus, wireless communication method, and integrated circuit - Google Patents

Description

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

  The evolution of cellular mobile radio access and wireless networks (hereinafter referred to as “Long Term Evolution (LTE)” or “Evolved Universal Terrestrial Radio Access (EUTRA)”) is the third generation partnership project (3rd Generation Partnership Project: 3GPP). In LTE, an Orthogonal Frequency Division Multiplexing (OFDM) system, which is multicarrier transmission, is used as a wireless communication (downlink) communication system from a base station apparatus to a mobile station apparatus. Further, as a communication system for radio communication (uplink) from the mobile station apparatus to the base station apparatus, an SC-FDMA (Single-Carrier Frequency Division Multiple Access) system that is single carrier transmission is used.

  In LTE, a base station apparatus uses uplink control information (or "uplink shared channel: UL-SCH") using downlink control information (Downlink Control Information: DCI) transmitted on PDCCH (Physical Downlink Control Channel). .) Instruct the mobile station apparatus to perform initial transmission or retransmission of PUSCH (Physical Uplink Shared Channel), which is a channel for transmission. In LTE, a mobile station apparatus transmits PUSCH using one transmission antenna port.

  In LTE-A, use of SU (single user) -MIMO (Multiple Input Multiple Output) for the PUSCH is being studied in order to improve uplink frequency utilization efficiency. By using SU-MIMO, the mobile station apparatus can spatially multiplex and transmit a plurality of uplink data to one PUSCH using a plurality of antenna ports. In LTE, a plurality of mobile station devices transmit data at the same time and the same frequency, and base station devices improve frequency utilization efficiency by separating one or more series of data transmitted by each mobile station device at the time of reception. MU (multi user) -MIMO, which is a technology to be used, is used, and it has been studied to extend the function of MU-MIMO in LTE-A.

  In LTE, a cyclic shift has been introduced in a reference signal (Demodulation Reference signal: DMRS) used for channel estimation transmitted together with PUSCH in order to reduce interference. Non-Patent Document 1 describes that an OCC (Orthogonal Cover Code) is introduced into DMRS in order to further reduce DMRS interference when performing SU-MIMO or MU-MIMO. Non-Patent Document 1 describes that information related to cyclic shift used for DMRS, which is included in downlink control information for PUSCH, is associated with OCC used for DMRS.

"OCC and CS for UL DMRS in SU / MU-MIMO", 3GPP TSG RAN WG1 Meeting # 60, R1-101267, February 22-26, 2010.

  However, in the conventional technique, the base station apparatus recognizes whether the mobile station apparatus operates as LTE and uses OCC for DMRS, or whether the mobile station apparatus operates as LTE-A and does not use OCC for DMRS. When it becomes impossible, the base station apparatus cannot correctly estimate the propagation path from the DMRS transmitted by the mobile station apparatus and cannot receive the PUSCH.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a radio communication system, a base station apparatus, and a mobile that can correctly receive PUSCH in a radio communication system using OCC for DMRS. An object is to provide a station apparatus, a wireless communication method, and an integrated circuit.

  (1) In order to achieve the above object, the present invention takes the following measures. That is, the terminal apparatus according to the present invention is a terminal apparatus that communicates with a base station apparatus, and performs demodulation related to PUSCH transmission based on a demodulated reference signal sequence provided by multiplying a reference signal sequence by a predetermined sequence. When a generation unit that generates a reference signal and a reception unit that receives downlink control information are provided, and the use of an orthogonal cover code for the demodulated reference signal is not set for downlink control information format 0, Alternatively, when temporary C-RNTI is used for transmission of the downlink control information, the predetermined sequence is [11], and use of the orthogonal cover code for the demodulation reference signal is set. And the temporary C-RNTI is not used for transmission of the downlink control information, the predetermined sequence is a size within the downlink control information. Based on the click shift information, it is one of [1 1] and [1 -1].

  (2) Moreover, the terminal device of this invention is further provided with the transmission part which transmits the said demodulation reference signal with PUSCH scheduled by the said downlink control information, It is characterized by the above-mentioned.

  (3) Moreover, the terminal apparatus of this invention is used for scheduling of the said PUSCH which the said downlink control information is transmitted using the said downlink control information format 0, and is transmitted with a single antenna port. It is characterized by that.

  (4) Also, in the base station apparatus of the present invention, the base station apparatus communicates with the terminal apparatus, and is provided by multiplying a transmitter that transmits downlink control information, a reference signal sequence, and a predetermined sequence. A reception unit that is generated based on the demodulation reference signal sequence and receives a demodulation reference signal related to PUSCH transmission, and for downlink control information format 0, use of an orthogonal cover code for the demodulation reference signal is provided. When not set or when temporary C-RNTI is used for transmission of the downlink control information, the predetermined sequence is [11], and the orthogonal cover code for the demodulation reference signal And the temporary C-RNTI is not used for transmission of the downlink control information, the predetermined sequence is the downlink link. One of [1 1] and [1 -1] is based on the cyclic shift information in the clock control information.

  (5) Moreover, the base station apparatus of this invention is further provided with the transmission part which transmits the said demodulation reference signal with PUSCH scheduled by the said downlink control information, It is characterized by the above-mentioned.

  (6) Moreover, the base station apparatus of this invention is used for the scheduling of the said PUSCH by which the said downlink control information is transmitted using the said downlink control information format 0, and is transmitted with a single antenna port. It is characterized by being able to.

  According to the present invention, in a radio communication system using OCC for DMRS, a base station apparatus can correctly receive PUSCH.

1 is a conceptual diagram of a wireless communication system according to a first embodiment of the present invention. It is the schematic which shows an example of a structure of the downlink radio frame of this invention. It is the schematic which shows an example of a structure of the uplink radio frame of this invention. It is the schematic for demonstrating the production | generation method of DMRS of this invention. It is the schematic which shows an example of a structure of the search area | region which arrange | positions PDCCH of this invention. It is a figure which shows the relationship between OCC applied to the uplink grant of this invention, and DMRS. It is a figure which shows the relationship between the cyclic shift information of this invention, and the cyclic shift applied to DMRS. It is a figure which shows the relationship between the cyclic shift information of this invention, the cyclic shift applied to DMRS, and OCC. It is a flowchart figure which shows an example of operation | movement of the mobile station apparatus 1 of this invention. It is a flowchart figure which shows an example of operation | movement of the base station apparatus 3 of this invention. It is a schematic block diagram which shows the structure of the mobile station apparatus 1 of this invention. It is a schematic block diagram which shows the structure of the base station apparatus 3 of this invention. It is a figure which shows the relationship of OCC applied to the uplink grant and DMRS of the 2nd Embodiment of this invention.

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

  First, the physical channel of the present invention will be described.

  FIG. 1 is a conceptual diagram of a radio communication system according to the first embodiment of the present invention. In FIG. 1, the radio communication system includes mobile station apparatuses 1 </ b> A to 1 </ b> C and a base station apparatus 3. FIG. 1 shows, in radio communication (downlink) from the base station apparatus 3 to the mobile station apparatuses 1A to 1C, a synchronization signal (Synchronization signal: SS), a downlink reference signal (Downlink Reference Signal: DL RS), and a physical broadcast channel (Physical Broadcast Channel: PBCH), Physical Downlink Control Channel (PDCCH), Physical Downlink Shared Channel (PDSCH), Physical Multicast Channel (PMCH), Physical Control Format This indicates that an indicator channel (Physical Control Format Indicator Channel: PCFICH) and a physical HARQ indicator channel (Physical Hybrid ARQ Indicator Channel: PHICH) are allocated.

  FIG. 1 illustrates uplink reference signals (UL RS), physical uplink control channels (Physical Uplink Control Channels) in radio communication (uplink) from the mobile station apparatuses 1A to 1C to the base station apparatus 3. : PUCCH), Physical Uplink Shared Channel (PUSCH), and Physical Random Access Channel (PRACH). Hereinafter, the mobile station apparatuses 1A to 1C are referred to as the mobile station apparatus 1.

  The synchronization signal is a signal used for the mobile station apparatus 1 to synchronize the downlink frequency domain and time domain. The downlink reference signal is used by the mobile station apparatus 1 to synchronize the downlink frequency domain and time domain, the mobile station apparatus 1 is used to measure downlink reception quality, or the mobile station This is a signal used by the device 1 to perform PDSCH or PDCCH propagation path correction. The PBCH is a physical channel used for broadcasting control parameters (system information) (Broadcast Channel: BCH) commonly used in the mobile station apparatus 1. PBCH is transmitted at intervals of 40 ms. The mobile station apparatus 1 performs blind detection at 40 ms intervals.

  The PDCCH is a physical channel used for transmitting downlink control information (Downlink Control Information: DCI) such as downlink assignment (also referred to as downlink assignment or downlink grant) and uplink grant (uplink grant). . The downlink assignment is composed of information (Modulation and Coding Scheme: MCS) on the modulation scheme and coding rate for PDSCH, information indicating radio resource allocation, and the like. The uplink grant is composed of information on the modulation scheme and coding rate for PUSCH, information indicating radio resource allocation, and the like.

  A plurality of formats are used for the downlink control information. The format of the downlink control information is called a DCI format (DCI format). For example, the DCI format of the uplink grant is DCI format 0 used when the mobile station apparatus 1 transmits PUSCH through one transmission antenna port, and the mobile station apparatus 1 uses MIMO SM (Multiple Input Multiple Output Spatial Multiplexing) as PUSCH. A DCI format 0A and the like used when transmitting a plurality of uplink data by using the. The mobile station apparatus 1 simultaneously monitors DCI format 0 and DCI format 0A for the PDCCH. When DCI format 0 is detected, PUSCH is transmitted using one transmission antenna port, and when DCI format 0A is detected. Transmits PUSCH using a plurality of transmit antenna ports (MIMO SM).

  MIMO SM is a technique in which a plurality of signals are multiplexed and transmitted / received on a plurality of spatial dimension channels realized by a plurality of transmission antenna ports and a plurality of reception antenna ports. Here, the antenna port indicates a logical antenna used for signal processing, and one antenna port may be configured by one physical antenna or may be configured by a plurality of physical antennas. Also good. On the transmission side using MIMO SM, a process (referred to as precoding) for forming an appropriate spatial channel is performed for a plurality of signals, and the plurality of signals subjected to the precoding process are processed. Are transmitted using a plurality of transmission antennas. On the receiving side using MIMO SM, processing for appropriately separating signals multiplexed on a spatial dimension channel is performed on a plurality of signals received using a plurality of receiving antennas.

  For example, in DCI format 0A, information (Resource block assignment) indicating radio resource allocation of PUSCH, TPC (Transmission Power Control) command used for PUSCH transmission power control, and uplink reference time-multiplexed with PUSCH Information used to determine the cyclic shift used for the signal (hereinafter referred to as cyclic shift information) (Cyclic shift for demodulation reference signal), the number of spatially multiplexed sequences, Information indicating precoding to be performed (precoding information), information on modulation scheme and coding scheme and redundancy version (Modulation and Coding Scheme and Redundancy version: MCS & RV), and information indicating initial transmission or retransmission of uplink data (New Data Indicator: NDI). The redundancy version is information indicating which part of the bit sequence in which the uplink data is encoded by the mobile station apparatus 1 is transmitted using PUSCH.

  The MCS & RV and NDI included in the DCI format 0A are prepared for each of a plurality of uplink data controlled by the DCI format 0A. That is, by using the DCI format 0A, the base station apparatus 3 can set the transport block size, the modulation scheme, and the coding rate for each uplink data transmitted on the same PUSCH, and each uplink data It is possible to instruct the mobile station apparatus 1 to perform initial transmission or retransmission.

  A method for encoding downlink control information will be described. First, the base station apparatus 3 adds, to the downlink control information, a sequence in which a cyclic redundancy check (CRC) code generated based on downlink control information is scrambled with an RNTI (Radio Network Temporary Identifier). . The mobile station apparatus 1 changes the interpretation of the downlink control information depending on which RNTI the cyclic redundancy check code is scrambled.

  For example, when the mobile station apparatus 1 has scrambled the cyclic redundancy check code with the C-RNTI (Cell-Radio Network Temporary Identity) assigned from the base station apparatus 3, the mobile station apparatus 1 stores the downlink control information in its own apparatus. When it is determined that the radio resource addressed to the destination station is indicated and the cyclic redundancy check code is scrambled by the SPS (Semi Persistent Scheduling) C-RNTI allocated from the base station apparatus 3, the downlink control information is It is determined that this indicates an allocation of a permanent (periodic) radio resource addressed to the own apparatus, a release of a permanent radio resource, or a retransmission of a PUSCH transmitted using the permanent radio resource.

  When the cyclic redundancy check code is scrambled by the T (Temporary) C-RNTI assigned to the random access preamble transmitted by the mobile station apparatus 1 by the random access message 2, the mobile station apparatus 1 stores the downlink control information. It is determined that it indicates a radio resource for retransmission of the random access message 3 transmitted by the own apparatus. Details of the random access will be described later.

  Hereinafter, the addition of a cyclic redundancy check code scrambled with RNTI to downlink control information is simply expressed as RNTI included in downlink control information or RNTI included in PDCCH.

  The mobile station apparatus 1 decodes the PDCCH, descrambles the sequence corresponding to the cyclic redundancy check code scrambled by the RNTI with the RNTI stored by the mobile station apparatus 1, and makes an error based on the descrambled cyclic redundancy check code. When it is detected that there is no PDCCH, it is determined that acquisition of the PDCCH is successful. This process is called blind decoding.

  PDSCH is a physical channel that is not broadcast on paging information (Paging Channel: PCH) or PBCH, that is, used to transmit system information other than BCH and downlink data (Downlink Shared Channel: DL-SCH). The PMCH is a physical channel used for transmitting information (Multicast Channel: MCH) related to MBMS (Multimedia Broadcast and Multicast Service). PCFICH is a physical channel used for transmitting information indicating an area where a PDCCH is arranged. The PHICH is a physical channel used for transmitting a HARQ indicator indicating success or failure of decoding of uplink data received by the base station apparatus 3.

  When the base station apparatus 3 successfully decodes all the uplink data included in the PUSCH, the HARQ indicator indicates ACK (ACKnowledgement), and the base station apparatus 3 decodes at least one uplink data included in the PUSCH. In case of failure, the HARQ indicator indicates NACK (Negative ACKnowledgement). A configuration in which a plurality of HARQ indicators indicating success or failure of decoding for each of a plurality of uplink data included in the same PUSCH may be transmitted by a plurality of PHICHs may be used.

  The uplink reference signal is used for the base station device 3 to synchronize the uplink time domain, the base station device 3 is used to measure uplink reception quality, or the base station device 3 It is a signal used to perform propagation channel correction for PUSCH and PUCCH. The uplink reference signal is subjected to code spreading using a CAZAC (Constant Amplitude and Zero Auto-Correlation) sequence in a radio resource divided assuming SC-FDMA.

  The CAZAC sequence is a sequence having a constant amplitude and excellent autocorrelation characteristics in the time domain and the frequency domain. Since the amplitude is constant in the time domain, the PAPR (Peak to Average Power Ratio) can be kept low. A cyclic delay is applied to the DMRS in the time domain. This cyclic delay in the time domain is called a cyclic shift. The cyclic shift corresponds to the phase rotation of the CAZAC sequence in sub-carrier units in the frequency domain.

  In the uplink reference signal, a DMRS (Demodulation Reference Signal) that is time-multiplexed with PUSCH or PUCCH and used for channel compensation of PUSCH and PUCCH, and base station apparatus 3 that is transmitted independently of PUSCH and PUCCH There is an SRS (Sounding Reference Signal) used to estimate the state of the uplink propagation path. In DMRS, not only cyclic shift but also OCC (Orthogonal Cover Code) is used. The OCC is a sequence (spreading code) in which a CAZAC sequence in the frequency domain is code-spread in units of SC-FDMA symbols in the time domain. Note that the time domain SC-FDMA symbol may be code-spread by OCC after the SC-FDMA symbol is generated.

  The OCC used for DMRS is determined using cyclic shift information included in the uplink grant. The amount of cyclic shift used for DMRS is assigned from the network by cyclic shift information included in the uplink grant, parameters specific to the base station device broadcast from the base station device, and cells managed by the base station device. It is determined from a random number with a physical cell identifier (Physical Cell ID) or the like as input.

  The PUCCH includes channel quality information indicating downlink channel quality, a scheduling request (SR) indicating a request for uplink radio resource allocation, and downlink data received by the mobile station apparatus 1. This is a physical channel used for transmitting uplink control information (UCI) that is information used for communication control, such as ACK / NACK indicating success or failure of decoding.

  PUSCH is a physical channel used for transmitting uplink data and uplink control information. PRACH is a physical channel used for transmitting a random access preamble. The PRACH is mainly used for the mobile station apparatus 1 to synchronize with the base station apparatus 3 in the time domain, and is also used for initial access, handover, reconnection request, and uplink radio resource allocation request. It is done.

  The random access according to the present invention will be described below.

  There are two access methods for random access: Contention based Random Access and Non-contention based Random Access. Contention based Random Access is an access method that may collide between mobile station apparatuses 1 and is a random access that is normally performed. Non-contention based Random Access is an access method in which no collision occurs between the mobile station apparatuses 1, and the base station is used in a special case such as a handover in order to quickly synchronize the mobile station apparatus 1 and the base station apparatus 3. This is random access performed by the device 3.

  In random access, the mobile station apparatus 1 transmits only the preamble for synchronization. The preamble includes a signature which is a signal pattern representing information, and several bits of information can be expressed by preparing dozens of types of signatures. Since the mobile station apparatus 1 transmits 6-bit information using a preamble, 64 types of signatures are prepared.

  When the base station apparatus 3 receives the preamble transmitted from the mobile station apparatus 1, the base station apparatus 3 calculates a synchronization timing shift between the mobile station apparatus 1 and the base station apparatus 3 from the preamble, and the mobile station apparatus 1 transmits the message 3. Scheduling for Then, the base station apparatus 3 allocates a TC-RNTI to the mobile station apparatus 1 that transmitted the preamble, and arranges an RA-RNTI (Random Access-Radio Network Temporary Identifer) corresponding to the PRACH that has received the preamble in the PDCCH. The PDSCH indicated by the radio resource allocation included in the PDCCH includes synchronization timing shift information, scheduling information, TC-RNTI, and a random number of the received preamble signature (also referred to as random ID or preamble ID). An access response (message 2) is transmitted.

  When the mobile station apparatus 1 confirms that the detected PDCCH includes the RA-RNTI, the mobile station apparatus 1 confirms the content of the random access response arranged in the PDSCH indicated by the radio resource allocation included in the PDCCH. The mobile station apparatus 1 extracts a response including the preamble signature number transmitted by the mobile station apparatus 1, corrects the synchronization timing shift, and is previously notified from the base station apparatus 3 in the allocated PUSCH radio resource and transmission format. Message 3 including a C-RNTI, a connection request message (RRCConnectionRequest message), or a connection reset request message (RRCConnectionReestablishmentRequest message).

  When the base station device 3 receives the message 3 from the mobile station device 1, the base station device 3 identifies the C-RNTI included in the received message 3, the connection request message, or the connection reset request message included in the mobile station device 1. Contention resolution (message 4) for determining whether or not a collision occurs between the mobile station apparatuses 1 using the information to be transmitted to the mobile station apparatus 1. When decoding of the message 3 fails, the base station apparatus 3 instructs the mobile station apparatus 1 to retransmit the message 3 using the DCI format 0 including the TC-RNTI corresponding to the message 3 that has failed to be decoded.

  Uplink data (UL-SCH) and downlink data (DL-SCH) are transport channels. A unit for transmitting uplink data by PUSCH and a unit for transmitting downlink data by PDSCH are called transport blocks. The transport block is a unit handled in a MAC (Media Access Control) layer, and HARQ (retransmission) control is performed for each transport block.

  In the physical layer, transport blocks are associated with codewords, and signal processing such as encoding is performed for each codeword. The transport block size is the number of bits of the transport block. The mobile station apparatus 1 recognizes the transport block size from the number of physical resource blocks (Physical Resource Blocks (PRB)) and MCS (MCS & RV) indicated by information indicating radio resource allocation included in the uplink grant or downlink assignment. .

  Hereinafter, the configuration of the radio frame of the present invention will be described.

  FIG. 2 is a schematic diagram illustrating an example of a configuration of a downlink radio frame according to the present invention. In FIG. 2, the horizontal axis is the time domain, and the vertical axis is the frequency domain. As shown in FIG. 2, the downlink radio frame is composed of a plurality of downlink physical resource block (PRB) pairs (for example, a region surrounded by a broken line in FIG. 2). This downlink physical resource block pair is a unit such as radio resource allocation, and has a predetermined frequency band (PRB bandwidth; 180 kHz) and time band (2 slots = 1 subframe; 1 ms).

  One downlink physical resource block pair is composed of two downlink physical resource blocks (PRB bandwidth × slot) that are continuous in the time domain. One downlink physical resource block (unit surrounded by a thick line in FIG. 2) is composed of 12 subcarriers (15 kHz) in the frequency domain, and 7 OFDM (Orthogonal Frequency Division) in the time domain. Multiplexing) symbol (71 μs).

  In the time domain, a slot composed of 7 OFDM symbols (71 μs) (0.5 ms), a subframe composed of 2 slots (1 ms), and a radio frame composed of 10 subframes ( 10 ms). 1 ms, which is the same time interval as the subframe, is also referred to as a transmission time interval (TTI). In the frequency domain, a plurality of downlink physical resource blocks are arranged according to the downlink bandwidth. A unit composed of one subcarrier and one OFDM symbol is referred to as a downlink resource element.

  Hereinafter, the arrangement of physical channels allocated to the downlink will be described. In each downlink subframe, PDCCH, PCFICH, PHICH, PDSCH, a downlink reference signal, and the like are arranged. The PDCCH is arranged from the first OFDM symbol of the subframe (the area hatched with a left oblique line in FIG. 2). The number of OFDM symbols in which the PDCCH is arranged is different for each subframe, and information indicating the number of OFDM symbols in which the PDCCH is arranged is broadcast by PCFICH. In each subframe, a plurality of PDCCHs are frequency multiplexed and time multiplexed.

  PCFICH is arranged in the first OFDM symbol of the subframe and is frequency-multiplexed with PDCCH. The PHICH is frequency-multiplexed within the same OFDM symbol as the PDCCH (the area hatched with grid lines in FIG. 2). The PHICH may be arranged only in the first OFDM symbol of the subframe, or may be arranged dispersed in a plurality of OFDM symbols in which the PDCCH is arranged. In each subframe, a plurality of PHICHs are frequency multiplexed and code multiplexed.

  The mobile station apparatus 1 receives HARQ feedback for this PUSCH in a downlink subframe PHICH after a predetermined time (for example, 4 ms later, 4 subframes later, 4 TTIs) after transmitting the PUSCH. The PHICH in which the HARQ indicator for the PUSCH is arranged in the downlink subframe is the number of the physical resource block having the smallest number (in the lowest frequency region) among the physical resource blocks allocated to this PUSCH. And it is determined from the information used for determining the cyclic shift used for the uplink reference signal time-multiplexed with PUSCH, which is included in the uplink grant.

  The PDSCH is arranged in an OFDM symbol other than the OFDM symbol in which the PDCCH, PCFICH, and PHICH of the subframe are arranged (in FIG. 2, a region that is not hatched). PDSCH radio resources are allocated using downlink assignment. The PDSCH radio resources are arranged in the same downlink subframe as the PDCCH including the downlink assignment used for the PDSCH allocation in the time domain. In each subframe, a plurality of PDSCHs are frequency-multiplexed and spatially multiplexed. The downlink reference signal is not shown in FIG. 2 for simplicity of explanation, but the downlink reference signal is distributed and arranged in the frequency domain and the time domain.

  FIG. 3 is a schematic diagram illustrating an example of a configuration of an uplink radio frame according to the present invention. In FIG. 3, the horizontal axis is the time domain, and the vertical axis is the frequency domain. As illustrated in FIG. 3, the uplink radio frame includes a plurality of uplink physical resource block pairs (for example, an area surrounded by a broken line in FIG. 3). This uplink physical resource block pair is a unit such as radio resource allocation, and has a predetermined frequency band (PRB bandwidth; 180 kHz) and time band (2 slots = 1 subframe; 1 ms).

  One uplink physical resource block pair is composed of two uplink physical resource blocks (PRB bandwidth × slot) that are continuous in the time domain. One uplink physical resource block (unit surrounded by a thick line in FIG. 3) is composed of 12 subcarriers (15 kHz) in the frequency domain, and 7 SC-FDMA symbols ( 71 μs).

  In the time domain, a slot (0.5 ms) composed of seven SC-FDMA (Single-Carrier Frequency Division Multiple Access) symbols (71 μs), a subframe (1 ms) composed of two slots, 10 There is a radio frame (10 ms) composed of subframes. 1 ms, which is the same time interval as the subframe, is also referred to as a transmission time interval (TTI). In the frequency domain, a plurality of uplink physical resource blocks are arranged according to the uplink bandwidth. A unit composed of one subcarrier and one SC-FDMA symbol is referred to as an uplink resource element.

  Hereinafter, physical channels allocated in the uplink radio frame will be described. PUCCH, PUSCH, PRACH, an uplink reference signal, etc. are arrange | positioned at each sub-frame of an uplink. The PUCCH is arranged in uplink physical resource blocks (regions hatched with left diagonal lines) at both ends of the uplink band. In each subframe, a plurality of PUCCHs are frequency multiplexed and code multiplexed.

  The PUSCH is arranged in an uplink physical resource block pair (an area that is not hatched) other than the uplink physical resource block in which the PUCCH is arranged. PUSCH radio resources are allocated using an uplink grant, and after a predetermined time from a downlink subframe in which a PDCCH including the uplink grant is arranged (for example, 4 ms later, 4 subframes later, 4 TTI later) Are arranged in uplink subframes. In each subframe, a plurality of PUSCHs are frequency multiplexed and spatially multiplexed.

  Information indicating a subframe in which the PRACH is arranged and an uplink physical resource block is broadcast by the base station apparatus. The uplink reference signal is time-multiplexed with PUCCH and PUSCH. For example, DMRS time-multiplexed with PUSCH is arranged in the fourth and eleventh SC-FDMA symbols in the subframe.

  FIG. 4 is a schematic diagram for explaining the DMRS generation method of the present invention. In FIG. 4, the horizontal axis is the time domain. First, a cyclic shift is applied to the CAZAC sequence generated by the mobile station device 1 (step S100). Next, the CAZAC sequence to which the cyclic shift is applied is duplicated into two (step S101) and multiplied by OCC (step S102).

  Next, the CAZAC sequence multiplied by the OCC is mapped to the physical resource block to which the PUSCH is assigned, and an inverse fast Fourier transform (IFFT) is performed to generate an SC-FDMA symbol (step S102). The generated SC-FDMA symbols are mapped as the fourth and eleventh SC-FDMA symbols in the subframe. Note that multiplying the OCC of [1, 1] corresponds to not applying the OCC to the DMRS (step S102 is omitted). Also, not applying OCC (omitting step S102) is equivalent to multiplying OCC of [1, 1].

  Hereinafter, the search space of the present invention will be described.

  FIG. 5 is a schematic diagram showing an example of a configuration of a search area in which the PDCCH according to the present invention is arranged. In FIG. 5, the horizontal axis is a number for identifying a control channel element (Control Channel Element: CCE). In FIG. 5, the unit surrounded by a thick line is a candidate (hereinafter referred to as “PDCCH candidate”) in which a PDCCH is arranged, which is composed of a plurality of consecutively-numbered control channel elements. In FIG. 5, the PDCCH candidates hatched with diagonal lines are PDCCH candidates in a mobile station apparatus specific search space (UE-specific Search Space: USS). The PDCCH candidates hatched in gray in FIG. 5 are PDCCH candidates in a common search space (Common Search Space: CSS).

  The common search area is an area common to a plurality of mobile station apparatuses 1 and is an area where a PDCCH for a plurality of mobile station apparatuses 1 and / or a PDCCH for a specific mobile station apparatus 1 is arranged. The mobile station apparatus specific search area is an area where a PDCCH for a specific mobile station apparatus 1 is arranged, and is an area configured for each mobile station apparatus 1.

  The search area is a set of PDCCH candidates (candidate). A PDCCH candidate is composed of a plurality of control channel elements (CCE). One control channel element is composed of a plurality of resource elements distributed in a frequency domain and a time domain in an OFDM symbol in which PDCCHs in the same subframe are arranged.

  In the search area, different search areas are formed for each number of control channel elements constituting the PDCCH candidate. In FIG. 5, different common search areas are configured for a PDCCH candidate composed of four control channel elements and a PDCCH candidate composed of eight control channel elements. Regarding the mobile station apparatus specific search region, a PDCCH candidate composed of one control channel element, a PDCCH candidate composed of two control channel elements, a PDCCH candidate composed of four control channel elements, and eight Different mobile station apparatus specific search areas are configured for PDCCH candidates configured by control channel elements.

  The common search area is composed of 0th to 15th control channel elements. The number of PDCCH candidates and the number of control channel elements constituting the mobile station apparatus specific search area are determined in advance, and the mobile station apparatus 1 uses the base station apparatus 3 as the control channel element number constituting the mobile station apparatus specific search area. Is determined from a hashing function with the C-RNTI assigned from the input as an input. In addition, a mobile station apparatus specific search region is configured from different control channel elements for each subframe.

  A part or all of different mobile station apparatus specific search areas for different mobile station apparatuses 1 may overlap. The plurality of mobile station apparatus specific search areas and the plurality of common search areas configured by the number of different control channel elements for the same mobile station apparatus 1 may be configured by the same control channel elements or different control channel elements. May be configured. That is, some or all of the PDCCH candidates constituting a plurality of different search areas may overlap.

  Hereinafter, the uplink transmission mode of the present invention will be described.

  FIG. 6 is a diagram showing the relationship between the uplink grant of the present invention and the OCC applied to DMRS. The mobile station apparatus 1 according to the present invention includes, as an uplink transmission mode, mode 1 that does not use OCC for DMRS that is time-multiplexed with PUSCH, and mode 2 that uses OCC for DMRS that is time-multiplexed with PUSCH. The uplink transmission mode of the mobile station device 1 is set by the base station device 3. The base station apparatus 3 notifies the mobile station apparatus 1 of information indicating the set uplink transmission mode using an RRC (Radio Resource Control) signal or the like. The RRC signal is information used for controlling radio resources transmitted on the PDSCH.

  In the mode 1 of the uplink transmission mode, the mobile station apparatus 1 includes DCI format 0 including C-RNTI, DCI format 0 including SPS C-RNTI, and DCI format 0 including TC-RNTI in the common search region. Blind decoding is performed, and DCI format 0 including C-RNTI and DCI format 0 including SPS C-RNTI are performed in the mobile station apparatus specific search region.

  In the mobile station apparatus 1 in mode 1, the OCC is invalid regardless of which RNTI is included in the DCI format 0. The invalid OCC means that the cyclic shift information included in the uplink grant is not associated with the OCC used for DMRS. “OCC is valid” means that the cyclic shift information included in the uplink grant is associated with the OCC used for DMRS.

  The mobile station apparatus 1 in mode 2 performs blind decoding of DCI format 0 including C-RNTI, DCI format 0 including SPS C-RNTI, and DCI format 0 including TC-RNTI in the common search region. Blind decoding of DCI format 0 and DCI format 0A including C-RNTI and DCI format 0 and DCI format 0A including SPS C-RNTI is performed in the mobile station apparatus specific search region.

  The mobile station apparatus 1 in mode 2 determines whether the OCC is valid or invalid depending on which RNTI is included in the uplink grant (DCI format 0 and DCI format 0A). The mobile station apparatus 1 in mode 2 determines that OCC is valid when C-RNTI is included in the uplink grant.

  Further, the mobile station apparatus 1 in mode 2 includes the SPS C-RNTI in the uplink grant, and the OCC is valid when the uplink grant instructs the retransmission of the PUSCH to which the uplink grant is permanently assigned. It is judged that. The mobile station apparatus 1 in mode 2 determines that the OCC is invalid when the uplink grant including the SPS C-RNTI does not instruct retransmission.

  When the uplink grant including the SPS C-RNTI indicates the retransmission of the PUSCH that is permanently assigned, the NDI value of this uplink grant is set to 1. If the uplink grant including the SPS C-RNTI is instructed to activate (or activate) or reconfigure or release the assignment of the PUSCH that is permanently assigned, the NDI of this uplink grant The value is set to 0.

  Further, when the uplink grant including the SPS C-RNTI does not instruct retransmission, that is, when the value of NDI is 0, the cyclic shift information included in the uplink grant is a specific code point (for example, ' 000 '). The period of PUSCH radio resources to be permanently assigned to the mobile station apparatus 1 is notified from the base station apparatus 3 to the mobile station apparatus 1 in advance by an RRC signal.

  The TC-RNTI is used to instruct the mobile station apparatus 1 to retransmit the random access message 3. However, since the base station apparatus 3 has failed to decode the message 3 including the information for identifying the mobile station apparatus 1, the base station apparatus 3 recognizes which mobile station apparatus 1 has transmitted the message 3. Can not.

  When the mobile station apparatus 1 in mode 1 invalidates the OCC and retransmits the message 3, and the mobile station apparatus 1 in mode 2 transmits the message 3 with the OCC enabled, the base station apparatus 3 transmits the PUSCH of the message 3 and Since it cannot be determined whether or not OCC is applied to DMRS that is time-multiplexed and transmitted, PUSCH propagation path compensation cannot be performed correctly and reception of message 3 fails.

  Therefore, the mobile station apparatus 1 in mode 2 determines that the OCC is invalid when the TC-RNTI is included in the DCI format 0, and applies the OCC to the DMRS when retransmitting the message 3. Without sending. Also, the mobile station device 1 transmits the message 3 without applying OCC to the DMRS even when the initial transmission of the message 3 is performed with the radio resource assigned by the random access response to the random access preamble transmitted by the mobile station device 1. Thereby, the base station apparatus 3 can correctly receive the message 3 by determining that the OCC is not used for the message 3.

  In the mobile station apparatus specific search area for the mobile station apparatus 1 in mode 2, only DCI format 0 or only DCI format 0A may be arranged as an uplink grant. A DCI format other than the DCI format shown in FIG. 6 may be arranged in the common search area and / or the mobile station apparatus specific search area, or a DCI format including an RNTI other than the RNTI shown in FIG. May be.

  FIG. 7 is a diagram illustrating the relationship between cyclic shift information applied to the DMRS and cyclic shift information when the mobile station apparatus 1 of the present invention determines that the OCC is invalid. When the mobile station apparatus 1 determines that the OCC is invalid, the mobile station apparatus 1 selects only the parameter for determining the cyclic shift applied to the DMRS from the cyclic shift information.

  FIG. 8 is a diagram illustrating a relationship between cyclic shift information applied to the DMRS and cyclic shift information when the mobile station apparatus 1 of the present invention determines that the OCC is valid. When determining that the OCC is valid, the mobile station apparatus 1 selects a parameter for determining a cyclic shift to be applied to the DMRS from the cyclic shift information and the OCC to be applied to the DMRS.

  In addition, when the base station apparatus 3 changes the setting of the uplink transmission mode of the mobile station apparatus 1 and notifies the mobile station apparatus 1 with the RRC signal to change the setting of the uplink transmission mode, the mobile station apparatus 1 The uplink transmission mode is changed after a certain amount of time has elapsed after receiving the RRC signal. After changing the uplink transmission mode, the mobile station apparatus 1 notifies the base station apparatus 3 of a message notifying that the change of the uplink transmission mode is completed.

  After the base station apparatus 3 notifies the mobile station apparatus 1 with the RRC signal to change the uplink transmission mode, the base station apparatus 3 receives from the mobile station apparatus 1 a message notifying that the change of the uplink transmission mode has been completed. In the meantime, since it is impossible to know when the mobile station apparatus 1 has changed the uplink transmission mode, a period during which the uplink transmission mode of the mobile station apparatus 1 cannot be grasped occurs.

  In this way, during the period in which the base station device 3 cannot grasp the uplink transmission mode of the mobile station device 1, the base station device 3 becomes the OCC of [1, 1] where the DMRS is the same as when the OCC is invalidated. The cyclic shift information of the corresponding value is included in the DCI format and transmitted to the mobile station apparatus 1 in mode 2. In FIG. 8, the cyclic shift information having values “000”, “001”, “011”, and “110” corresponds to the OCC [1, 1].

  Thereby, even if the uplink transmission mode of the mobile station apparatus 1 is mode 2 and OCC is enabled during the period in which the base station apparatus 3 cannot grasp the uplink transmission mode of the mobile station apparatus 1, the mobile station apparatus 1 Uses only [1, 1] OCC whose DMRS is the same as when OCC is disabled, so that the base station device 3 does not depend on the uplink transmission mode of the mobile station device 1 and the mobile station device 1 It is possible to correctly receive the PUSCH by performing the PUSCH reception process on the assumption that no is used.

  When the mobile station apparatus 1 initially accesses the base station apparatus 3, if the base station apparatus 3 does not know the uplink transmission mode of the mobile station apparatus 1, the PUSCH transmitted by the mobile station apparatus 1 is transmitted to the base station apparatus 3. Cannot be received correctly, it is necessary to determine the default uplink transmission mode. In the present invention, the uplink transmission mode of the mobile station apparatus 1 when the mobile station apparatus 1 initially accesses the base station apparatus 3 is set to mode 1 in which DMRS transmission processing is simple.

  Hereinafter, the operation of the apparatus of the present invention will be described.

  FIG. 9 is a flowchart showing an example of the operation of the mobile station apparatus 1 of the present invention. The mobile station apparatus 1 sets the uplink transmission mode notified from the base station apparatus 3 (step S200). The mobile station apparatus 1 performs blind decoding of the uplink grant and detects the uplink grant (step S201). The mobile station apparatus 1 determines whether its own uplink transmission mode is mode 1 or mode 2 (step S202). If the mobile station device 1 determines that its uplink transmission mode is mode 2, the mobile station device 1 determines whether or not to apply OCC to DMRS from the RNTI included in the uplink grant (step S203).

  The mobile station device 1 includes the SPS C-RNTI assigned to the own device in the uplink grant and instructs retransmission, and the C-RNTI assigned to the own device in the uplink grant. If so, the OCC and cyclic shift to be applied to the DMRS are determined based on the cyclic shift information of the uplink grant (step S204).

  The mobile station apparatus 1 includes the SPS C-RNTI assigned to the own apparatus in the uplink grant and has not instructed retransmission, and the T C- corresponding to the random access message 3 in the uplink grant. If RNTI is included, only the cyclic shift to be applied to DMRS is determined based on the cyclic shift information of the uplink grant (step S205).

  If the mobile station apparatus 1 determines in step S202 that its uplink transmission mode is mode 1, the mobile station apparatus 1 proceeds to step S205. The mobile station apparatus 1 applies the cyclic shift determined in step S204 or step S205 and, if necessary, the OCC to the DMRS, and time-multiplexes and transmits the DMRS and PUSCH (step S206).

  FIG. 10 is a flowchart showing an example of the operation of the base station apparatus 3 of the present invention. The base station apparatus 3 notifies the mobile station apparatus 1 of the transmission mode set for the mobile station apparatus 1 using an RRC signal or the like (step S300).

  The base station apparatus 3 performs PUSCH scheduling and transmits an uplink grant indicating the radio resources of the scheduled PUSCH to the mobile station apparatus 1 (step S301). The base station apparatus 3 includes cyclic shift information corresponding to only the parameter for determining the cyclic shift used for DMRS in the uplink grant for the mobile station apparatus 1 set to mode 1. The base station apparatus 3 receives only cyclic shift information corresponding to only a parameter for determining the cyclic shift used for DMRS in the uplink grant to which the radio resource of the PUSCH for retransmission of the message 3 including TC-RNTI is assigned. include.

  In the uplink grant including the C-RNTI for the mobile station apparatus 1 set to mode 2, the base station apparatus 3 uses a parameter for determining a cyclic shift used for DMRS and a cyclic shift corresponding to the OCC used for DMRS. Include information. The base station apparatus 3 includes an SPS C-RNTI for the mobile station apparatus 1 set to mode 2 and an uplink grant for instructing PUSCH retransmission, a parameter for determining a cyclic shift used for DMRS and DMRS. The cyclic shift information corresponding to the OCC to be used is included.

  For the uplink grant that includes the SPS C-RNTI for the mobile station device 1 set to mode 2 and that does not instruct the retransmission of PUSCH, the base station device 3 supports only the parameter for determining the cyclic shift used for DMRS. Include cyclic shift information. The base station apparatus 3 receives the PUSCH and DMRS according to the uplink grant transmitted to the mobile station apparatus 1 in step S301, compensates the PUSCH propagation path using the DMRS, and performs PUSCH decoding processing (step S302). .

  The apparatus configuration of the present invention will be described below.

  FIG. 11 is a schematic block diagram showing the configuration of the mobile station apparatus 1 of the present invention. As illustrated, the mobile station apparatus 1 includes an upper layer processing unit 101, a control unit 103, a receiving unit 105, a transmitting unit 107, and a transmission / reception antenna 109. The upper layer processing unit 101 includes a radio resource control unit 1011 and a determination unit 1013. The reception unit 105 includes a decoding unit 1051, a demodulation unit 1053, a demultiplexing unit 1055, a radio reception unit 1057, and a channel measurement unit 1059. The transmission unit 107 includes an encoding unit 1071, a modulation unit 1073, a multiplexing unit 1075, a radio transmission unit 1077, and an uplink reference signal generation unit 1079.

  Upper layer processing section 101 outputs uplink data generated by a user operation or the like to transmitting section 107. The upper layer processing unit 101 includes a medium access control (MAC) layer, a packet data integration protocol (PDCP) layer, a radio link control (Radio Link Control: RLC) layer, and radio resource control. Process the (Radio Resource Control: RRC) layer. Further, upper layer processing section 101 generates control information for controlling receiving section 105 and transmitting section 107 based on downlink control information received by PDCCH, and outputs the control information to control section 103.

  The radio resource control unit 1011 included in the higher layer processing unit 101 manages various setting information of the own device. For example, the radio resource control unit 1011 manages an RNTI such as C-RNTI and a reverse link transmission mode. Also, the radio resource control unit 1011 generates information arranged in each uplink channel and outputs the information to the transmission unit 107.

  The determination unit 1013 included in the upper layer processing unit 101 uses the OCC that the cyclic shift information included in the uplink grant is applied to the DMRS, using the uplink transmission mode or RNTI managed by the radio resource control unit 1011. It is determined whether or not it is compatible. In addition, based on the determination result, the determination unit 1013 determines a cyclic shift and OCC to be applied to the DMRS from the cyclic shift information, and performs control to apply the cyclic shift and OCC determined by the transmission unit 107 to the DMRS. Information is generated and output to the control unit 103.

  The control unit 103 generates a control signal for controlling the reception unit 105 and the transmission unit 107 based on the control information from the higher layer processing unit 101. Control unit 103 outputs the generated control signal to receiving unit 105 and transmitting unit 107 to control receiving unit 105 and transmitting unit 107. The receiving unit 105 separates, demodulates, and decodes the received signal received from the base station apparatus 3 via the transmission / reception antenna 109 according to the control signal input from the control unit 103, and sends the decoded information to the upper layer processing unit 101. Output.

  The radio reception unit 1057 converts the downlink signal received via the transmission / reception antenna 109 to an intermediate frequency (down covert), removes unnecessary frequency components, and maintains the signal level appropriately. Then, the amplification level is controlled, quadrature demodulation is performed based on the in-phase component and the quadrature component of the received signal, and the quadrature demodulated analog signal is converted into a digital signal. The radio reception unit 1057 removes a portion corresponding to a guard interval (GI) from the converted digital signal, performs a fast Fourier transform (FFT) on the signal from which the guard interval has been removed, and performs frequency conversion. Extract the region signal.

  The demultiplexing unit 1055 separates the extracted signal into PHICH, PDCCH, PDSCH, and downlink reference signal. This separation is performed based on the radio resource allocation information notified by the downlink assignment. Further, demultiplexing section 1055 compensates the propagation path of PHICH, PDCCH, and PDSCH from the estimated propagation path value input from channel measurement section 1059. Also, the demultiplexing unit 1055 outputs the demultiplexed downlink reference signal to the channel measurement unit 1059.

  Demodulation section 1053 multiplies the PHICH by a corresponding code and synthesizes, demodulates the synthesized signal using a BPSK (Binary Phase Shift Keying) modulation method, and outputs the result to decoding section 1051. Decoding section 1051 decodes the PHICH addressed to the own apparatus, and outputs the decoded HARQ indicator to higher layer processing section 101. Demodulation section 1053 demodulates the QPSK modulation scheme for PDCCH and outputs the result to decoding section 1051. Decoding section 1051 attempts blind decoding of PDCCH, and when blind decoding is successful, decodes downlink control information and outputs RNTI included in downlink control information to higher layer processing section 101.

  Demodulation section 1053 demodulates the modulation scheme notified by downlink assignment such as QPSK (Quadrature Phase Shift Keying), 16QAM (Quadrature Amplitude Modulation), 64QAM, etc., to PDSCH and outputs the result to decoding section 1051. . The decoding unit 1051 performs decoding based on the information regarding the coding rate notified by the downlink control information, and outputs the decoded downlink data (transport block) to the higher layer processing unit 101.

  Channel measurement section 1059 measures the downlink path loss and channel state from the downlink reference signal input from demultiplexing section 1055, and outputs the measured path loss and channel state to higher layer processing section 101. Also, channel measurement section 1059 calculates an estimated value of the downlink propagation path from the downlink reference signal, and outputs it to demultiplexing section 1055.

  The transmission unit 107 generates an uplink reference signal according to the control signal input from the control unit 103, encodes and modulates the uplink data (transport block) input from the higher layer processing unit 101, PUCCH, The PUSCH and the generated uplink reference signal are multiplexed and transmitted to the base station apparatus 3 via the transmission / reception antenna 109. The coding unit 1071 performs coding such as convolution coding and block coding on the uplink control information input from the higher layer processing unit 101, and relates to the coding rate notified of the uplink data by the uplink grant. Turbo coding is performed based on the information.

  The modulation unit 1073 modulates the coded bits input from the coding unit 1071 using a modulation method notified by downlink control information such as BPSK, QPSK, 16QAM, 64QAM, or a modulation method predetermined for each channel. . Modulation section 1073 transmits the same PUSCH using MIMO SM based on the number of spatially multiplexed sequences notified by the uplink grant and information indicating precoding performed on the sequences. A sequence of modulation symbols of a plurality of uplink data is mapped to a plurality of sequences larger than the number of uplink data transmitted on the same PUSCH, and precoding is performed on the sequences.

  The uplink reference signal generation unit 1079 is a physical cell identifier (physical cell identity: referred to as PCI, Cell ID, etc.) for identifying the base station device 3, a bandwidth for arranging the uplink reference signal, and an uplink grant. Based on the notified cyclic shift or the like, the base station apparatus 3 obtains a known sequence that is obtained by a predetermined rule. The multiplexing unit 1075 rearranges the PUSCH modulation symbols in parallel according to the control signal input from the control unit 103, and then performs discrete Fourier transform (DFT) to generate the PUCCH and PUSCH signals and the generated uplink reference The signal is multiplexed for each transmission antenna port.

  Radio transmission section 1077 performs inverse fast Fourier transform (IFFT) on the multiplexed signal, performs SC-FDMA modulation, and adds a guard interval to the SC-FDMA-modulated SC-FDMA symbol. Generating a baseband digital signal, converting the baseband digital signal to an analog signal, generating an in-phase component and a quadrature component of an intermediate frequency from the analog signal, removing an extra frequency component for the intermediate frequency band, The intermediate frequency signal is converted to a high frequency signal (up convert), the excess frequency component is removed, the power is amplified, and output to the transmission / reception antenna 109 for transmission.

  FIG. 12 is a schematic block diagram showing the configuration of the base station apparatus 3 of the present invention. As illustrated, the base station apparatus 3 includes an upper layer processing unit 301, a control unit 303, a reception unit 305, a transmission unit 307, and a transmission / reception antenna 309. The upper layer processing unit 301 includes a radio resource control unit 3011 and a downlink control information generation unit 3013. The reception unit 305 includes a decoding unit 3051, a demodulation unit 3053, a demultiplexing unit 3055, a wireless reception unit 3057, and a channel measurement unit 3059. The transmission unit 307 includes an encoding unit 3071, a modulation unit 3073, a multiplexing unit 3075, a radio transmission unit 3077, and a downlink reference signal generation unit 3079.

  The upper layer processing unit 301 includes a medium access control (MAC) layer, a packet data integration protocol (PDCP) layer, a radio link control (RLC) layer, and a radio resource control (Radio). Resource Control (RRC) layer processing. Further, upper layer processing section 301 generates control information for controlling receiving section 305 and transmitting section 307 and outputs the control information to control section 303.

  The radio resource control unit 3011 included in the upper layer processing unit 301 generates downlink data (transport block), RRC signal, and MAC CE (Control Element) arranged in the downlink PDSCH, or acquires from the upper node. And output to the transmission unit 307. Further, the radio resource control unit 3011 manages various setting information of each mobile station apparatus 1. For example, the radio resource control unit 3011 performs RNTI management such as allocating C-RNTI to the mobile station apparatus 1 and management of the uplink transmission mode set in the mobile station apparatus 1.

  A downlink control information generation unit 3013 included in the higher layer processing unit 301 generates downlink control information transmitted on the PDCCH. The downlink control information generation unit 3013 generates an uplink grant that includes cyclic shift information corresponding to the OCC used for DMRS and an uplink grant that includes cyclic shift information that does not correspond to the OCC used for DMRS.

  The downlink control information generation unit 3013 determines which uplink grant is to be generated, the uplink transmission mode set in the mobile station apparatus 1 managed by the radio resource control unit 3011, and the PUSCH with a permanent uplink grant. It is determined depending on whether the radio resource is indicated, the radio resource of PUSCH of only one subframe is indicated, whether the uplink grant indicates retransmission of the message 3 or the like.

  The control unit 303 generates a control signal for controlling the reception unit 305 and the transmission unit 307 based on the control information from the higher layer processing unit 301. The control unit 303 outputs the generated control signal to the reception unit 305 and the transmission unit 307 and controls the reception unit 305 and the transmission unit 307.

  The receiving unit 305 separates, demodulates and decodes the received signal received from the mobile station apparatus 1 via the transmission / reception antenna 309 according to the control signal input from the control unit 303, and outputs the decoded information to the higher layer processing unit 301. To do. The radio reception unit 3057 converts an uplink signal received via the transmission / reception antenna 309 into an intermediate frequency (down covert), removes unnecessary frequency components, and appropriately maintains the signal level. In this way, the amplification level is controlled, and based on the in-phase and quadrature components of the received signal, quadrature demodulation is performed, and the quadrature demodulated analog signal is converted into a digital signal.

  The wireless reception unit 3057 removes a portion corresponding to a guard interval (GI) from the converted digital signal. The radio reception unit 3057 performs fast Fourier transform (FFT) on the signal from which the guard interval is removed, extracts a signal in the frequency domain, and outputs the signal to the demultiplexing unit 3055.

  The demultiplexing unit 1055 demultiplexes the signal input from the radio reception unit 3057 into signals such as PUCCH, PUSCH, and uplink reference signal. This separation is performed based on radio resource allocation information included in the uplink grant that is determined in advance by the radio resource control unit 3011 by the base station device 3 and notified to each mobile station device 1. In addition, demultiplexing section 3055 compensates for the propagation paths of PUCCH and PUSCH from the propagation path estimation value input from channel measurement section 3059. Further, the demultiplexing unit 3055 outputs the separated uplink reference signal to the channel measurement unit 3059.

  The demodulating unit 3053 performs inverse discrete Fourier transform (IDFT) on the PUSCH, obtains modulation symbols, and performs BPSK (Binary Phase Shift Keying), QPSK, 16QAM, PUCCH and PUSCH modulation symbols, respectively. The received signal is demodulated using a predetermined modulation scheme such as 64QAM, or a modulation scheme that the own device has previously notified to each mobile station device 1 using an uplink grant. Demodulation section 3053 is the same by using MIMO SM based on the number of spatially multiplexed sequences notified in advance to each mobile station apparatus 1 using an uplink grant and information indicating precoding to be performed on the sequences. The modulation symbols of a plurality of uplink data transmitted on the PUSCH are separated.

  The decoding unit 3051 encodes the demodulated PUCCH and PUSCH encoded bits in a predetermined encoding method in advance or the mobile station apparatus 1 previously notified to the mobile station apparatus 1 using an uplink grant. Decoding is performed at a rate, and the decoded uplink data and uplink control information are output to the upper layer processing section 101. When PUSCH is retransmitted, decoding section 3051 performs decoding using the encoded bits held in the HARQ buffer input from higher layer processing section 301 and the demodulated encoded bits. Channel measurement section 309 measures an estimated channel value, channel quality, and the like from the uplink reference signal input from demultiplexing section 3055 and outputs the result to demultiplexing section 3055 and higher layer processing section 301.

  The transmission unit 307 generates a downlink reference signal according to the control signal input from the control unit 303, encodes and modulates the HARQ indicator, downlink control information, and downlink data input from the higher layer processing unit 301. Then, the PHICH, PDCCH, PDSCH, and downlink reference signal are multiplexed, and the signal is transmitted to the mobile station device 1 via the transmission / reception antenna 309.

  The encoding unit 3071 is a predetermined encoding method such as block encoding, convolutional encoding, turbo encoding, and the like for the HARQ indicator, downlink control information, and downlink data input from the higher layer processing unit 301 Or is encoded using the encoding method determined by the radio resource control unit 3011. The modulation unit 3073 modulates the coded bits input from the coding unit 3071 with a modulation scheme determined in advance by the radio resource control unit 3011 such as BPSK, QPSK, 16QAM, and 64QAM.

  The downlink reference signal generation unit 3079 uses, as a downlink reference signal, a sequence known by the mobile station apparatus 1 that is obtained by a predetermined rule based on a physical cell identifier (PCI) for identifying the base station apparatus 3 or the like. Generate. The multiplexing unit 3075 multiplexes the modulated modulation symbol of each channel and the generated downlink reference signal.

  The radio transmission unit 3077 performs inverse fast Fourier transform (IFFT) on the multiplexed modulation symbols and the like, performs modulation of the OFDM scheme, adds a guard interval to the OFDM symbol that has been OFDM-modulated, and baseband The baseband digital signal is converted to an analog signal, the in-phase and quadrature components of the intermediate frequency are generated from the analog signal, the extra frequency components for the intermediate frequency band are removed, and the intermediate-frequency signal is generated. Is converted to a high-frequency signal (up-convert: up-convert), an extra frequency component is removed, power is amplified, and output to the transmission / reception antenna 309 for transmission.

  Thus, according to the present invention, in the wireless communication system in which the base station device 3 and the mobile station device 1 perform wireless communication, the base station device 3 is time-multiplexed with the PUSCH (data channel) by the mobile station device 1. To determine an uplink grant (first control information) including cyclic shift information corresponding to a parameter for determining a cyclic shift used for DMRS (reference signal) to be transmitted, and a cyclic shift used for DMRS And a different RNTI (identifier) in the uplink grant (second control information) including the cyclic shift information corresponding to the parameters and OCC (spreading code) used for DMRS.

  Then, the mobile station apparatus 1 uses the RNTI included in the detected uplink grant to determine the cyclic shift used for the DMRS in which the cyclic shift information included in the detected uplink grant is time-multiplexed with the PUSCH. And whether it corresponds to the OCC used for DMRS, or only the parameter for determining the cyclic shift used for DMRS time-multiplexed with PUSCH.

  As a result, the base station apparatus 3 can accurately recognize whether or not the mobile station apparatus 1 is applying OCC to the DMRS that is time-multiplexed with the PUSCH. Can be performed correctly and PUSCH can be decoded.

(Second Embodiment)
Hereinafter, a second embodiment of the present invention will be described in detail with reference to the drawings.

  In the second embodiment of the present invention, the base station apparatus 3 shares an uplink grant (first control information) including cyclic shift information corresponding to only a parameter for determining a cyclic shift used for DMRS. An uplink grant (second control information) including a parameter for determining a cyclic shift used for DMRS and cyclic shift information corresponding to the OCC used for DMRS is arranged in the search area (first search area). It arrange | positions to a mobile station apparatus specific search area (2nd search area).

  In the second embodiment of the present invention, the mobile station device 1 determines the cyclic shift information included in the detected uplink grant depending on whether the uplink grant is detected in the common search region or the mobile station device specific search region. It corresponds to whether only the parameter for determining the cyclic shift used for DMRS corresponds to the parameter for determining the cyclic shift used for DMRS and the OCC used for DMRS.

  FIG. 13 is a diagram illustrating the relationship between the uplink grant and the OCC applied to DMRS according to the second embodiment of this invention. The mobile station apparatus 1 of 2nd Embodiment is provided with the mode 1 which does not use OCC for DMRS time-multiplexed with PUSCH as an uplink transmission mode, and mode 2 which uses OCC for DMRS time-multiplexed with PUSCH.

  In the mode 1 of the uplink transmission mode, the mobile station apparatus 1 includes DCI format 0 including C-RNTI, DCI format 0 including SPS C-RNTI, and DCI format 0 including TC-RNTI in the common search region. Blind decoding is performed, and DCI format 0 including C-RNTI and DCI format 0 including SPS C-RNTI are performed in the mobile station apparatus specific search region. In mode 1, OCC is invalid regardless of in which search area DCI format 0 is detected.

  In mode 2 of the uplink transmission mode, the mobile station apparatus 1 is configured to perform DCI format 0 including C-RNTI, DCI format 0 including SPS C-RNTI, and DCI format 0 including TC-RNTI in the common search region. Blind decoding is performed, and DCI format 0 and DCI format 0A including C-RNTI and DCI format 0 and DCI format 0A including SPS C-RNTI are performed in the mobile station apparatus specific search region.

  The mobile station apparatus 1 in mode 2 determines whether the OCC is valid or invalid depending on whether the DCI format 0 and the DCI format 0A are detected in the common search area or the mobile station apparatus specific search area. The mobile station apparatus 1 in mode 2 determines that OCC is invalid when DCI format 0 is detected in the common search area. When the mobile station apparatus 1 in mode 2 detects DCI format 0 and DCI format 0A including C-RNTI in the mobile station apparatus specific search region, it determines that OCC is valid. Since the mobile station apparatus 1 in mode 2 monitors the DCI format 0A only in the mobile station apparatus specific search area, the DCI format 0A always has OCC effective.

  When the mobile station apparatus 1 in mode 2 detects DCI format 0 and DCI format 0A including the SPS C-RNTI instructing retransmission in the mobile station apparatus specific search region, it determines that OCC is valid. When the mobile station apparatus 1 in mode 2 detects DCI format 0 and DCI format 0A not instructing retransmission including the SPS C-RNTI in the mobile station apparatus specific search area, it determines that the OCC is invalid.

  If at least a part of the common search area and the mobile station apparatus specific search area overlap, is the DCI format 0 detected in the overlapped area arranged for the common search area and the OCC is invalid? There is a problem that the mobile station apparatus 1 cannot determine whether the OCC is valid because it is arranged for the mobile station apparatus specific search region.

  Note that the common search area and the mobile station apparatus specific search area overlap means that the PDCCH candidates constituting the common search area and the PDCCH candidates constituting the mobile station apparatus specific search area are all configured by the same control channel element. . In FIG. 5, PDCCH candidates composed of control channel elements from No. 8 to No. 15 are areas where the common search area and the mobile station apparatus specific search area overlap.

  Therefore, in the present invention, DCI format 0 arranged for both the common search area and the mobile station apparatus specific search area is either when the common search area and the mobile station apparatus specific search area overlap. It is determined in advance whether the search area is arranged as DCI format 0. When the mobile station apparatus 1 detects DCI format 0 arranged for both the common search area and the mobile station apparatus specific search area in an area where the common search area and the mobile station apparatus specific search area overlap, It is determined that the DCI format is for the determined search area.

  For example, when DCI format 0 is detected in an area where the common search area and the mobile station apparatus specific search area overlap, DCI format 0 is for the common search area and mobile station apparatus 1 determines in advance that OCC is invalid. Decide it.

  Thereby, the base station apparatus 3 transmits a RRC signal instructing the mobile station apparatus 1 to change the uplink transmission mode, and then sends a message informing the mobile station apparatus 1 that the change of the uplink transmission mode has been completed. During the period in which the uplink transmission mode of the mobile station device 1 cannot be grasped until reception, the mobile station device 1 always has OCC disabled regardless of the uplink transmission mode by using the DCI format 0 arranged in the common search area. Since it is determined that the mobile station apparatus 1 is present, it is possible to accurately recognize whether or not the OCC is applied to the DMRS that is time-multiplexed with the PUSCH.

  In addition, since the base station apparatus 3 can perform radio communication with the mobile station apparatus 1 by using the uplink grant including the C-RNTI of the common search area in the above period, the SPS C-RNTI of the common search area OCC of the uplink grant including

  A program that operates in the base station apparatus 3 and the mobile station apparatus 1 related to the present invention is a program (computer function) that controls a CPU (Central Processing Unit) or the like so as to realize the functions of the above-described embodiments related to the present invention. Program). Information handled by these devices is temporarily stored in RAM (Random Access Memory) during the processing, and then stored in various ROMs such as Flash ROM (Read Only Memory) and HDD (Hard Disk Drive). Reading, correction, and writing are performed by the CPU as necessary.

  In addition, you may make it implement | achieve the mobile station apparatus 1 in the embodiment mentioned above, and a part of base station apparatus 3 with a computer. In that case, the program for realizing the control function may be recorded on a computer-readable recording medium, and the program recorded on the recording medium may be read by the computer system and executed.

  Here, the “computer system” is a computer system built in the mobile station apparatus 1 or the base station apparatus 3 and 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.

  Furthermore, the “computer-readable recording medium” is a medium that dynamically holds a program for a short time, such as a communication line when transmitting a program via a network such as the Internet or a communication line such as a telephone line, In such a case, a volatile memory inside a computer system serving as a server or a client may be included and a program that holds a program for a certain period of time. 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.

  Furthermore, the terminal device according to the present invention can take the following means. In other words, it is a terminal device that communicates with the base station device, and is used for scheduling of PUSCH transmitted through a single antenna port, and RRC information indicating whether or not to use OCC for DMRS used for PUSCH demodulation. A radio resource controller configured to set whether or not OCC is used for DMRS based on the received RRC information, and a RS sequence A generating unit configured to generate a DMRS from a DMRS sequence obtained by multiplying a predetermined sequence, and a transmitting unit configured to transmit the DMRS together with a PUSCH scheduled by the DCI The DMRS related to generating the DMRS transmitted with the PUSCH scheduled by the DCI when the OCRS is configured not to be used for DMRS based on the received RRC information. The fixed sequence is [1 1], and when the temporary C-RNTI is used for transmission of the DCI, the predetermined sequence related to generation of the DMRS transmitted together with the PUSCH scheduled by the DCI is [1 1], when OCC is set to be used for DMRS based on the received RRC information, and temporary C-RNTI is not used for transmission of the DCI, it is scheduled by the DCI. The predetermined sequence related to generation of the DMRS transmitted together with the PUSCH is specified based on cyclic shift information included in the DCI, and is any one of [1 1] and [1 -1] .

  Further, the terminal apparatus is related to generation of the DMRS transmitted together with the PUSCH scheduled by the DCI until it is set whether or not OCC is used for DMRS based on the received RRC information. The identified sequence is [1 1].

  Further, a base station device that communicates with a terminal device, the radio resource control unit configured to instruct whether or not the terminal device uses OCC to DMRS used for demodulation of PUSCH, and to DMRS A transmitter configured to transmit RRC information indicating whether to use the OCC and a DCI used for scheduling of a PUSCH transmitted through a single antenna port; A receiver configured to demodulate the PUSCH by using the DMRS generated from the DMRS sequence obtained by receiving the DMRS together with the PUSCH and multiplying the RS sequence by a predetermined sequence. When the terminal apparatus does not use OCC for DMRS, the predetermined sequence related to generation of the DMRS received with the PUSCH scheduled by the DCI is [1 1], and temporary C-RNTI Is used for transmission of the DCI, the predetermined sequence related to the generation of the DMRS received together with the PUSCH scheduled by the DCI is [11], and the terminal device adds an OCC to the DMRS. And if the temporary C-RNTI is not used for transmission of the DCI, the predetermined sequence related to the generation of the DMRS received with the PUSCH scheduled by the DCI is included in the DCI One of [1 1] and [1 -1] is selected based on the cyclic shift information.

  In addition, until the RRC information is transmitted, the predetermined sequence related to generation of the DMRS received together with the PUSCH scheduled by the DCI is [11].

  Further, it is a method used for a terminal device that communicates with a base station device, and RRC information indicating whether or not to use OCC for DMRS used for PUSCH demodulation, and PUSCH transmitted by a single antenna port. Means for receiving DCI used for scheduling; means for setting whether or not OCC is used in DMRS based on the received RRC information; and multiplying RS sequence by a predetermined sequence Means for generating a DMRS from the DMRS sequence obtained by the above and means for transmitting the DMRS together with the PUSCH scheduled by the DCI so that OCC is not used for the DMRS based on the received RRC information. If set, the predetermined sequence related to generation of the DMRS transmitted with the PUSCH scheduled by the DCI is [1 1], and a temporary C-RNTI was used to transmit the DCI In case The predetermined sequence related to generation of the DMRS transmitted with the PUSCH scheduled by the DCI is [1 1], and is configured to use OCC for DMRS based on the received RRC information, If the temporary C-RNTI is not used for transmission of the DCI, the predetermined sequence related to generation of the DMRS transmitted together with the PUSCH scheduled by the DCI is a cyclic shift included in the DCI. It is specified based on the information and is either [1 1] or [1 -1].

  Further, a method used in a base station apparatus that communicates with a terminal apparatus, the DMRS used for demodulation of PUSCH instructing whether or not the terminal apparatus uses OCC, and using the OCC in the DMRS Means for transmitting RRC information indicating whether to perform, DCI used for scheduling of PUSCH transmitted by a single antenna port, means for receiving the DMRS together with PUSCH scheduled by the DCI, Means for demodulating the PUSCH by using the DMRS generated from the DMRS sequence obtained by multiplying the RS sequence by a predetermined sequence, and when the terminal apparatus does not use OCC for DMRS The predetermined sequence related to the generation of the DMRS received with the PUSCH scheduled by the DCI is [11], and if the temporary C-RNTI is used for the transmission of the DCI, the DCI Yo The predetermined sequence related to generation of the DMRS received together with the scheduled PUSCH is [11], the terminal device uses OCC for DMRS, and the temporary C-RNTI is the DCI If not used for transmission, the predetermined sequence related to the generation of the DMRS received with the PUSCH scheduled by the DCI is based on cyclic shift information included in the DCI [11] and Either [1 -1] is selected.

  Further, an integrated circuit mounted on a terminal device that communicates with a base station device, which transmits RRC information indicating whether or not to use OCC for DMRS used for PUSCH demodulation and a single antenna port. A function for receiving DCI used for PUSCH scheduling, a function for setting whether or not OCC is used for DMRS based on the received RRC information, and multiplying an RS sequence by a predetermined sequence The terminal device exhibits a series of functions including a function of generating a DMRS from a DMRS sequence obtained by performing a function of transmitting the DMRS together with a PUSCH scheduled by the DCI, and the received RRC. If the OCRS is configured not to be used for DMRS based on information, the predetermined sequence related to generation of the DMRS transmitted with the PUSCH scheduled by the DCI is [1 1] and temporary When C-RNTI is used for transmission of the DCI, the predetermined sequence related to generation of the DMRS transmitted with the PUSCH scheduled by the DCI is [1 1], and the received RRC If the OCRS is configured to be used for DMRS based on information and temporary C-RNTI is not used for transmission of the DCI, it is related to the generation of the DMRS transmitted with the PUSCH scheduled by the DCI The predetermined sequence to be performed is identified based on cyclic shift information included in the DCI, and is any one of [11] and [1-1].

  As described above, the embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to the above, and various design changes and the like can be made without departing from the scope of the present invention. It is possible to

1 (1A, 1B, 1C) Mobile station apparatus 3 Base station apparatus 101 Upper layer processing section 103 Control section 105 Reception section 107 Transmission section 301 Upper layer processing section 303 Control section 305 Reception section 307 Transmission section 1011 Radio resource control section 1013 Unit 3011 radio resource control unit 3013 downlink control information generation unit

Claims (6)

A terminal device that communicates with a base station device,
A generating unit that generates a demodulated reference signal related to PUSCH transmission based on a demodulated reference signal sequence given by multiplying a reference signal sequence by a predetermined sequence;
A receiving unit for receiving downlink control information,
For downlink control information format 0,
When the use of an orthogonal cover code for the demodulation reference signal is not set, or when temporary C-RNTI is used for transmission of the downlink control information, the predetermined sequence is [11]. Yes,
When the use of the orthogonal cover code for the demodulation reference signal is set and temporary C-RNTI is not used for transmission of the downlink control information, the predetermined sequence is the downlink control information. One of [1 1] and [1 −1] based on the cyclic shift information in
A terminal device characterized by that. The terminal device according to claim 1, further comprising: a transmission unit that transmits the demodulation reference signal together with the PUSCH scheduled by the downlink control information. The terminal apparatus according to claim 1, wherein the downlink control information is transmitted using the downlink control information format 0 and is used for scheduling of the PUSCH transmitted through a single antenna port. A base station device that communicates with a terminal device,
A transmitter for transmitting downlink control information;
A reception unit that receives a demodulation reference signal that is generated based on a demodulation reference signal sequence that is given by multiplying a reference signal sequence by a predetermined sequence and that is related to PUSCH transmission, and
For downlink control information format 0,
When the use of an orthogonal cover code for the demodulation reference signal is not set, or when temporary C-RNTI is used for transmission of the downlink control information, the predetermined sequence is [11]. Yes,
When the use of the orthogonal cover code for the demodulation reference signal is set and temporary C-RNTI is not used for transmission of the downlink control information, the predetermined sequence is the downlink control information. One of [1 1] and [1 −1] based on the cyclic shift information in
A base station apparatus. The base station apparatus according to claim 4, further comprising: a transmission unit that transmits the demodulation reference signal together with the PUSCH scheduled by the downlink control information. The base station apparatus according to claim 4, wherein the downlink control information is transmitted using the downlink control information format 0 and used for scheduling of the PUSCH transmitted through a single antenna port.