JP2013110759A - Base station and processing method for mobile communication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently transmit a reference signal to each user device located in an identical cell and having a different number of physical antennas.SOLUTION: A base station device includes: a plurality of physical antennas including M physical antennas (#1, #3, #5, #7) in a first group and M physical antennas (#2, #4, #6, #8) in a second group; a reference signal multiplexing unit for multiplexing at least M types of reference signals (P#1 to P#4) in a downward signal resource block; and a transmitter for radio transmitting a downward signal. The M types of reference signals are multiplexed into a first and a second resource block with an identical layout pattern. The M types of reference signals (P#1 to P#4) in the first resource block are transmitted from the physical antennas (#1, #3, #5, #7) in the first group, whereas the M types of reference signals in the second resource block are transmitted from the physical antennas (#2, #4, #6, #8) in the second group.

Description

  The disclosed invention relates to a technical field of mobile communication, and particularly relates to a base station, a user apparatus, a processing method, and the like in a mobile communication system in which user apparatuses having different numbers of physical antennas are mixed in the same cell.

  In the technical field of mobile communications, a so-called third generation successor is being studied by the standardization organization 3GPP of the wideband code division multiple access (W-CDMA) system. In particular, a long term evolution (LTE) system can be cited as a successor to the W-CDMA system, the high-speed downlink packet access (HSDPA) system, the high-speed uplink packet access (HSUPA) system, and the like. Furthermore, as a successor of the LTE system, a system such as an LTE advanced system or a fourth generation mobile communication system is also being studied. The downlink radio access scheme in the LTE system is an orthogonal frequency division multiple access (OFDMA) scheme. For the uplink, a single-carrier frequency division multiple access (SC-FDMA) scheme is used.

  In the LTE system, communication is performed by allocating one or more resource blocks (RBs) to user apparatuses in both downlink and uplink. The resource block indicates a frequency unit for radio resource allocation and is shared by many user apparatuses in the system. As an example, one resource block has a bandwidth of 180 kHz and includes, for example, 12 subcarriers. For example, a system band of 5 MHz includes 25 resource blocks. For example, in the LTE system, the base station apparatus determines to which user apparatus among a plurality of user apparatuses a resource block is allocated for each subframe (Sub-frame) of 1 ms. The subframe may be referred to as a transmission time interval (TTI). The determination of radio resource allocation is called scheduling. In the case of downlink, the base station apparatus transmits a shared channel using one or more resource blocks to the user apparatus selected by scheduling. This shared channel is called a downlink physical shared channel (PDSCH: Physical Downlink Shared CHannel). In the uplink, the user apparatus selected by scheduling transmits a shared channel to the base station apparatus using one or more resource blocks. This shared channel is called an uplink physical shared channel (PUSCH: Physical Uplink Shared CHannel).

  In the communication system using the shared channel as described above, it is necessary to notify the user apparatus which user apparatus is assigned the shared channel for each subframe. The control channel used for this notification is called a physical downlink control channel (PDCCH: Physical Downlink Control CHannel) or a downlink L1 / L2 control channel (DL-L1 / L2 Control Channel). In addition to the PDCCH, the downlink control signal may include a physical control format indicator channel (PCFICH), a physical hybrid ARQ indicator channel (PHICH), and the like.

The PDCCH may include, for example, the following information:
・ Downlink Scheduling Grant,
-Uplink Scheduling Grant and-Transmission Power Control Command Bit.

  The downlink scheduling grant information includes, for example, information related to the downlink shared channel, specifically, downlink resource block allocation information, user apparatus identification information (UE-ID), number of streams, precoding Information on vectors (Pre-coding Vector), data size, modulation scheme, information on HARQ (Hybrid Automatic Repeat reQuest), and the like are included.

  Further, the uplink scheduling grant information includes, for example, information related to the uplink shared channel, specifically, uplink resource allocation information, user apparatus identification information (UE-ID), data size, The information includes a modulation scheme, uplink transmission power information, information on a demodulation reference signal in uplink MIMO (Multiple Input Multiple Output), and the like.

  PCFICH is information for notifying the format of PDCCH. More specifically, the number of OFDM symbols to which PDCCH is mapped is notified by PCFICH. In the LTE system, the number of OFDM symbols mapped to the PDCCH is 1, 2 or 3, and mapping is performed in order from the first OFDM symbol of the subframe.

  The PHICH includes acknowledgment information (ACK / NACK: Acknowledgement / Non-Acknowledgement information) indicating whether retransmission is required for the PUSCH transmitted in the uplink.

  In addition, although it is a problem of definition of terms, the control signals of PDCCH, PCFICH, and PHICH may be defined as equal and independent channels, respectively, or are defined so that PCFICH and PHICH are included in PDCCH. Also good.

  In the uplink, user data (normal data signal) and control information are transmitted by PUSCH. Separately from PUSCH, downlink quality information (CQI: Channel Quality Indicator), PDSCH delivery confirmation information (ACK / NACK), and the like are transmitted by an uplink control channel (PUCCH: Physical Uplink Control CHannel). CQI is used for scheduling processing, adaptive modulation and demodulation, channel coding processing (AMC: Adaptive Modulation and channel Coding) and the like of a shared physical channel in the downlink. In the uplink, a random access channel (RACH: Random Access CHannel), a signal indicating an uplink / downlink radio resource allocation request, and the like are transmitted as necessary.

  The LTE system is described in, for example, Non-Patent Document 1 and the like.

International Publication No. 2008/050453

3GPP, TS36.211 V8.4.0, September 2008 NTT DoCoMo, Support of DL Higher-Order MIMO Transmission in LTE-Advanced, 3GPP R1-083685, October 3, 2008 Yoshihisa Kishiyama 3 others, Study of broadcast channel configuration in Evolved UTRA downlink using OFDM, IEICE Technical Report, November 9, 2006, Vol.106, No.360, pp.83-87, RCS2006 171

  By the way, in the LTE system, a MIMO transmission scheme using a maximum of four transmission antennas is used in the downlink. In the case of the MIMO transmission system, each of a plurality of physical antennas used for communication forms an independent radio propagation path, and thus it is necessary to measure a channel state for each physical antenna. For this reason, according to the number of transmission antennas 4 of the base station, four types of reference signals are transmitted on the downlink.

  FIG. 1 shows an example of reference signal mapping in the LTE system. This is described in Chapter 6.10 “Reference Signals” of the above non-patent document. The reference signal is a known reference signal on the transmission side and the reception side, and may be referred to as a pilot signal, a training signal, a known signal, or the like. Based on the reception status of the reference signal, the quality of the radio propagation path is estimated, the channel is estimated, and the like. In the case of FIG. 1, reference signals P # 1 and P # 2 transmitted from the first and second antennas are multiplexed on the 1, 5, 8 and 12th OFDM symbols. Reference signals P3 and P4 transmitted from the third and fourth antennas are multiplexed on the 2nd and 9th OFDM symbols.

  On the other hand, in radio access succeeding LTE such as IMT Advanced (IMT-A) or LTE Advanced (LTE-A) system, the number of transmission antennas used in the base station may be increased from four (for example, , The number of transmit antennas may be eight). In this case, when the base station uses eight physical antennas, an LTE-A mobile station (a mobile station having the capability required by the LTE-A system) also receives a reference signal from each physical antenna of the base station. It is desired to receive the signals separately and measure the channel state corresponding to each physical antenna.

  On the other hand, from the viewpoint of realizing a smooth transition from the LTE system to the LTE-A system, it is desired to sufficiently ensure backward compatibility or backward compatibility in the LTE-A system. In the case of the above example, it is necessary to ensure compatibility between an LTE system in which it is not essential to distinguish between more than four physical antennas and an LTE-A system in which eight physical antennas must be distinguished. is there.

  FIG. 2 shows an example of the use of radio resources that can be considered when coexistence of the LTE system and the LTE-A system is realized. The radio resource is divided in the frequency direction into a frequency band (radio resource A) used for communication by the LTE-A mobile station and a frequency band (radio resource B) used for communication by the LTE mobile station. The LTE-A mobile station performs communication using one or more resource blocks (resource allocation units) included in the radio resource A. The LTE mobile station performs communication using one or more resource blocks included in the resource block B. Since the LTE-A mobile station communicates with the radio resource A, the base station can multiplex the reference signal with the downlink signal in an arrangement suitable for the LTE-A system. For example, a resource block including eight types of reference signals may be included in the radio resource A. Further, in resource block B, since the LTE mobile station communicates, the base station can multiplex the reference signal with the downlink signal in an arrangement suitable for the LTE mobile station. For example, a resource block including four types of reference signals may be included in the radio resource B.

  FIG. 3 shows another usage example of radio resources that can be considered when coexistence of the LTE system and the LTE-A system is realized. The radio resource is divided in a time direction into a period (radio resource A) used for communication by the LTE-A mobile station and a period (radio resource B) used for communication by the LTE mobile station. In this case as well, in the radio resource A, the base station multiplexes the reference signal into the resource block in an arrangement suitable for the LTE-A mobile station. In radio resource B, the base station multiplexes reference signals into resource blocks in an arrangement suitable for LTE mobile stations.

  In both FIG. 2 and FIG. 3, the radio resource is fixedly divided for the LTE system and the LTE-A system. This is preferable in that radio resources can be secured in each system. However, it is not always preferable from the viewpoint of the efficiency of using radio resources. For example, at the beginning of LTE-A system, it is expected that there will not be many LTE-A mobile stations, and it is difficult to expect that radio resource A reserved for LTE-A system will be fully utilized from the beginning. It is. Although it is conceivable to change the boundary of radio resources A and B semi-statically or dynamically, it is feared that it is difficult to always maintain the boundary position optimally because it causes processing complexity. .

  FIG. 4 shows still another usage example of radio resources that can be considered when coexistence of the LTE system and the LTE-A system is realized. For example, the scheduler of the base station allocates optimal resource blocks to the LTE mobile station and the LTE-A mobile station based on channel quality information (CQI) reported from each mobile station. Therefore, the resource block A allocated to the LTE-A mobile station and the resource block B allocated to the LTE mobile station change for each subframe. In the resource block A allocated to the LTE-A mobile station, a reference signal suitable for the LTE-A mobile station is multiplexed by the base station. For example, eight types of reference signals are multiplexed on the resource block A. In the resource block B allocated to the LTE mobile station, a reference signal suitable for the LTE mobile station is multiplexed by the base station. For example, four types of reference signals are multiplexed on the resource block A. In the case of the example shown in FIG. 4, since the radio resources for the LTE system and the LTE-A system are not determined in advance, there is a problem that is concerned about the use of radio resources as shown in FIG. 2 and FIG. It may be possible to effectively cope with the problem that radio resources may not be used effectively.

  By the way, the mobile station must report the quality of radio propagation status (CQI) to the base station whether or not the radio resource for the shared data channel is allocated. In the case of the example of FIG. 4, the resource block allocated to the LTE mobile station includes four types of reference signals, and the resource block allocated to the LTE-A mobile station includes eight types of reference signals. This means that if no LTE-A mobile station has been assigned radio resources in the downlink, all eight types of reference signals are not transmitted, and channel conditions are measured using the eight reference signals. And it becomes difficult to properly report the measurement values to the base station. In the example shown in FIGS. 2 and 3, since the radio resource A always includes eight reference signals for LTE-A, such a problem does not occur, but the use efficiency of the radio resource is deteriorated. Concerned.

  As described above, both when the radio resources are fixedly divided for the LTE system and the LTE-A system (FIGS. 2 and 3) and when the radio resources are dynamically scheduled (FIG. 4), It is not optimal from the viewpoint of efficiently transmitting signals.

  An object of the present invention is to efficiently transmit a reference signal to user apparatuses having different numbers of physical antennas located in the same cell.

  It should be noted that not all configurations and procedures described in the column “Problems to be Solved by the Invention” have been proven in the past.

A base station according to the disclosed invention is
A first antenna group corresponding to the first reference signal group;
A second antenna group corresponding to the second reference signal group;
For each of a plurality of resource blocks included in a downlink signal, a reference signal belonging to the first reference signal group is multiplexed in the same arrangement pattern, and among the plurality of resource blocks, a resource block that is allocated to a specific user apparatus, A reference signal multiplexing unit that multiplexes reference signals belonging to the second reference signal group in another arrangement pattern different from the arrangement pattern;
And a transmission unit that transmits the downlink signal using the first and second antenna groups.

  According to the disclosed invention, it is possible to efficiently transmit a reference signal to user apparatuses having different numbers of physical antennas located in the same cell.

The figure which shows the example of mapping of a reference signal. The figure which shows the utilization example of a radio | wireless resource. The figure which shows another example of utilization of a radio | wireless resource. The figure which shows another example of utilization of a radio | wireless resource. The flowchart which shows the operation example by one Example of this invention. The figure which shows the structural example (example changed for every subband) of the downlink signal by one Example of this invention. The figure which shows the detail of a 1st and 2nd resource block. The figure which shows the example of correspondence of a reference signal (P # 1-P # 4) and a physical antenna (# 1- # 4). The figure which shows the structural example (example changed for every sub-frame) of the downlink signal by one Example of this invention. The figure which shows the structural example (example changed for every subband and sub-frame) of the downlink signal by one Example of this invention. The figure which shows the detail of the resource block allocated to a user apparatus. The figure which shows the example of correspondence of a reference signal (P # 1-P # 8) and a physical antenna (# 1- # 8). The figure which shows the base station apparatus by one Example of this invention. The figure which shows the user apparatus by one Example of this invention.

[Overview]
According to an aspect of the present invention, the plurality of physical antennas of the base station apparatus includes M (= 4) (# 1, # 3, # 5, # 7) in the first group and M (( = 4) Divided into books (# 2, # 4, # 6, # 8). Radio resources are also classified into a resource block (first resource block) of RB group A and a resource block (second resource block) of RB group B. The M types of reference signals are multiplexed on the first and second resource blocks in the same arrangement pattern (FIG. 7). Then, M (= 4) types of reference signals (P # 1 to P # 4) in the first resource block are transmitted from the first group of physical antennas (# 1, # 3, # 5, # 7). Is done. M (= 4) types of reference signals (P # 1 to P # 4) in the second resource block are transmitted from the physical antennas (# 2, # 4, # 6, # 8) of the second group. .

  The LTE user apparatus measures the four types of channel states using the four types of reference signals P # 1 to P # 4 in the resource block and reports them to the base station. Since any resource block includes four types of reference signals in the same arrangement pattern, any resource block may be allocated to the LTE user apparatus. The LTE-A user apparatus uses the reference signals P # 1 to P # 4 in the first resource block for the M physical antennas (# 1, # 3, # 5, # 7) of the first group. To measure the channel condition. The LTE-A user apparatus then uses the reference signal P # 1 in the second resource block for the M (= 4) physical antennas (# 2, # 4, # 6, # 8) of the second group. Use ~ P # 4 to measure the channel state. The LTE-A user apparatus having 8 reception antennas recognizes that the physical transmission antennas of the reference signals P # 1 to P # 4 are different between the first and second resource blocks, and thereby performs eight physical transmissions. The channel conditions for the antenna can be measured. The LTE user apparatus having four reception antennas does not consider that the physical transmission antennas of the reference signals P # 1 to P # 4 are different between the first and second resource blocks. The LTE user apparatus extracts the reference signals P # 1 to P # 4 in the same manner for the first resource block and the second resource block, and performs measurement as channel states related to the four physical transmission antennas. In other words, the LTE-A user equipment has M (= 4) (# 1, # 3, # 5, # 7) in the first group and M (= 4) (# 2, # 7) in the second group. 4, # 6, # 8) are distinguished from each other, but the LTE user equipment does not distinguish them.

  In this way, any resource block can be allocated to LTE and LTE-A user equipment. In addition, even if no LTE-A user apparatus is assigned radio resources, the first and second resource blocks are always prepared in the downlink, so that the LTE-A user apparatus The channel state can be appropriately measured for the physical transmission antenna. Therefore, according to an aspect of the present invention, it is possible to efficiently transmit the reference signal to both the LTE user apparatus and the LTE-A user apparatus while ensuring backward compatibility.

  The correspondence relationship between the M (= 4) types of reference signals and the M (= 4) physical antennas in the first and second groups may be broadcast to the user apparatus through a broadcast channel. From the viewpoint of notifying any information to the user apparatus, it is not essential to be a broadcast channel, but from the viewpoint of efficiently notifying a large number of users of information that can be changed, it is preferable to broadcast using a broadcast channel.

  One time subframe may include both the first and second resource blocks. Since both the first and second resource blocks can be acquired during one time subframe, this is preferable from the viewpoint of shortening the processing time.

  A predetermined plurality of first resource blocks (and / or a predetermined plurality of second resource blocks) may be prepared adjacent to each other in the frequency direction. The channel state measurement using the reference signal may be performed for each resource block. However, from the viewpoint of reducing the amount of control information required for reporting the measurement value, the average value for a plurality of resource blocks is reported to the base station apparatus. It is desirable that Therefore, it is preferable that the same four types of reference signals are transmitted from the same four physical antennas in each resource block from which the average value is based.

  A first resource block may be included in a certain time subframe, and a second resource block may be included in a subsequent time subframe. This is preferable from the viewpoint that the channel state can be measured for the same frequency band.

  The first resource block may be included in a certain time subframe, and the second resource block may also be included in the time subframe and another time subframe. This is preferable from the viewpoint of enabling the LTE-A user apparatus to increase the options for aligning the first and second resource block pairs and to prepare a more appropriate pair.

  The reference signal multiplexing unit multiplexes the reference signal into the downlink signal so that the resource block of the specific user apparatus includes P types of reference signals different from the M types of reference signals in addition to the M types of reference signals. (Typically, M = P = 4). In this case, the resource block allocated to the LTE-A user apparatus includes reference signals from all physical transmission antennas. This is preferable from the viewpoint of measuring the channel state of each physical transmission antenna with high accuracy regarding the resource block allocated to the LTE-A user apparatus.

[Detailed Description of Embodiment]
From the following viewpoints, embodiments of the disclosed invention will be described.

1. Example of operation Modification (time direction)
3. Modified example (time and frequency direction)
4). Modification (Individual reference signal)
5. Base station 6. User device < 1. Example of operation >
Hereinafter, an operation example according to an embodiment of the present invention will be described. The mobile communication system in the operation description includes a plurality of user apparatuses and a plurality of base station apparatuses, and the base station apparatus is connected to a higher station of the core network. Among the plurality of user apparatuses, a user apparatus (LTE_UE) used in the LTE system and a user apparatus (LTE-A_UE) used in the LTE-A system are included. The user equipment is typically a mobile station, but may be a fixed station. LTE_UE communicates using four physical antennas. LTE-A_UE communicates using eight physical antennas. The base station apparatus is shared by both systems.

  FIG. 5 is a flowchart showing an operation example according to an embodiment of the present invention. In step S11, the base station apparatus transmits a broadcast signal (BCH: Broadcast Channel) to a plurality of user apparatuses located in the cell. The broadcast information included in the broadcast signal (BCH) includes system bandwidth, system frame number, cell ID, and other system information. In this operation example, in particular, reference signals (P # 1, P # 2, ...) transmitted in the downlink, physical antennas (# 1, # 2, ...) used in the base station apparatus Information such as the correspondence between the reference signal and the physical antenna and the configuration of the resource block is included in the broadcast information. The contents of these information may be fixed in the system invariably, but may be changed regularly or irregularly.

  In step S12, the base station apparatus determines radio resource allocation by performing so-called scheduling. Scheduling is performed based on downlink and uplink radio propagation conditions. Scheduling may be performed by any suitable algorithm known in the art. As an example, the scheduling may be performed based on a proportional fairness method.

  In step S13, a signal to be transmitted on the downlink is created. In general, the downstream signal includes a control signal, a reference signal, and a shared data signal. The downlink radio resource allocation content is included in the control signal as a downlink scheduling grant. The content of uplink radio resource allocation is included in the control signal as an uplink scheduling grant. A control signal including uplink and downlink scheduling grants is particularly referred to as a downlink physical control channel (PDCCH) in the LTE system. When creating the downlink signal, the control signal, the reference signal, and the shared data signal are appropriately multiplexed from the viewpoint of both time and frequency.

  FIG. 6 shows a configuration example of a downlink signal according to an embodiment of the present invention. A state for 8 subframes is shown in the time axis direction, and a state for 10 resource blocks is shown in the frequency axis direction. The resource block including the shared data signal and the control signal are time multiplexed. For simplicity of illustration, the reference signal and shared data signal are not shown in detail in FIG. In this embodiment, resource blocks are classified into a group called RB group A and a group called RB group B. Resource blocks belonging to RB group A are also referred to as first resource blocks. Resource blocks belonging to RB group B are also referred to as second resource blocks. In the illustrated example, five resource blocks on the low frequency side (left side) belong to RB group A. The five resource blocks on the high frequency side (left side) belong to RB group B. In the figure, a region surrounded by a broken-line ellipse includes first and second resource blocks, and details of this portion are shown in FIG.

  FIG. 7 shows details of the first and second resource blocks. In the figure, the left side corresponds to the first resource block (RB group A), and the right side corresponds to the second resource block (RB group B). One resource block includes a predetermined number of OFDM symbols and a predetermined number of subcarriers, and the number of symbols and the number of subcarriers may be any suitable numbers. As an example, one resource block may include 14 OFDM symbols spanning 1 ms and 12 subcarriers spanning 180 kHz. As shown in the figure, the same four types of reference signals (P # 1 to P # 4) are mapped to the first and second resource blocks in the same arrangement pattern. However, the first resource block (left side) reference signals P # 1 to P # 4 and the second resource block (right side) reference signals P # 1 to P # 4 are transmitted from different physical antennas.

  FIG. 8 shows an example of the correspondence between four types of reference signals (P # 1 to P # 4) and physical antennas (# 1 to # 4). The four types of reference signals (P # 1 to P # 4) correspond to the above P # 1 to P # 4. In the present embodiment, the eight physical antennas of the base station apparatus are divided into first and second groups. In the first resource block belonging to RB group A, four types of reference signals P # 1 to P # 4 are transmitted from the physical antennas # 1, # 3, # 5, and # 7 of the first group, respectively. In the second resource block belonging to RB group B, the same four types of reference signals P # 1 to P # 4 are transmitted from the physical antennas # 2, # 4, # 6, and # 8 of the second group, respectively.

  In the example shown in FIG. 8, one reference signal is transmitted from one physical antenna in order to simplify the explanation, but this is not essential. For example, by using precoding, one reference signal may be transmitted in a specific direction from four physical antennas. In any case, the same four types of reference signals need to be transmitted from a certain group (four physical antennas) and another group (another four physical antennas). The correspondence shown in FIG. 8 is merely an example, and any appropriate correspondence or antenna grouping may be made. For example, the first group may be composed of # 1, # 2, # 3, and # 4 in ascending order, and the second group may be composed of # 5, # 6, # 7, and # 8. These correspondence relationships may be fixed in the system invariably, or may be changed regularly or irregularly.

  In step S13 of FIG. 5, a resource block having such a configuration is constructed, and this downlink signal is transmitted in step S14. As described above, in this operation example, the user apparatus LTE_UE and the user apparatus LTE-A_UE are connected to the same base station apparatus. First, an operation in the case of the user apparatus LTE_UE will be described, and then an operation in the case of the user apparatus LTE-A_UE will be described.

<For LTE_UE>
In step S21, the control signal in the downlink signal is extracted from the received signal, demodulated, and decoded. This control signal is a signal including radio link allocation information, and corresponds to the PDCCH in the LTE system. When restoring the control signal, it is necessary to perform channel estimation. Information regarding where the reference signal is mapped in the resource block is included in the broadcast information, and the user apparatus LTE_UE has already acquired the broadcast information. The user apparatus LTE_UE extracts reference signals (P # 1 to P # 4) from the received signal, and performs channel estimation based on them. The user apparatus LTE_UE performs channel compensation of the control signal using the channel estimation result. The user apparatus LTE_UE confirms downlink and / or uplink scheduling grant from the control signal after channel compensation, and confirms whether or not radio resources are allocated to the own apparatus. For convenience of explanation, it is assumed that this user apparatus LTE_UE has been allocated downlink radio resources.

  In step S22, a group of physical antennas is confirmed. Specifically, the correspondence between the reference signals P # 1 to P # 4 and the physical antenna of the base station apparatus is confirmed from the broadcast information and the allocated resource block. However, in the case of user apparatus LTE_UE, the process of this step is not essential.

  In step S23, the channel state of each reference signal with respect to the propagation path is measured based on the reference signals P # 1 to P # 4. Specifically, when resource blocks of RB group A are allocated to the user apparatus LTE_UE, physical antennas # 1, # 3, # 5, and # 7 of the base station apparatus and four physical antennas of the user apparatus LTE_UE The channel state between is measured. Channels between physical antennas # 2, # 4, # 6 and # 8 of the base station apparatus and four physical antennas of the user apparatus LTE_UE when resource blocks of RB group B are allocated to the user apparatus LTE_UE The state is measured. In the case of the user apparatus LTE_UE, it is not essential to distinguish between more than four physical antennas, so it is not necessary to distinguish the first and second groups of physical antennas of the base station apparatus.

  In step S24, the downlink shared data signal is reproduced while using the channel estimation result for each of the four antennas.

  In step S25, the reception status measurement result for 4 antennas and / or the acknowledgment signal (ACK / NACK) of the downlink shared data signal is transmitted to the base station apparatus.

  Even if the resource block is not allocated for the downlink shared data signal of the user apparatus LTE_UE, the user apparatus LTE_UE performs channel state measurement using the reference signals P # 1 to P # 4 as necessary, and performs measurement. The result may be reported to the base station apparatus. For example, user apparatus LTE_UE may measure a channel state about the resource block instruct | indicated from the base station apparatus, and may report a measurement result by PUCCH.

  According to this embodiment, four types of reference signals are mapped in the same arrangement pattern in any resource block. In the case of LTE user equipment LTE_UE, it is not essential to distinguish more than four physical antennas, so the physical antennas of the base station equipment are the first group (# 1, # 3, # 5, # 7). It is not necessary to distinguish between the second group (# 2, # 4, # 6, and # 8). Therefore, the LTE user apparatus LTE_UE can receive any resource block assignment.

<LTE-A_UE>
Next, an operation when the user apparatus is LTE-A_UE will be described. The operation in step S21 is the same as in LTE_UE. In the case of LTE-A_UE, it is necessary to distinguish each of the eight physical antennas and measure the channel state of each physical antenna in preparation for MIMO communication using eight physical antennas. This point is greatly different from LTE_UE.

  In step S22, a group of physical antennas is confirmed. Specifically, the correspondence between the reference signals P # 1 to P # 4 and the physical antenna of the base station apparatus is confirmed from the broadcast information and the allocated resource block. If the resource block is the first resource block belonging to RB group A, the four types of reference signals P # 1 to P # 4 are the physical antennas # 1, # 3, # 5 and # 7 of the first group. Each is sent from. When the resource block is a second resource block belonging to RB group B, the same four types of reference signals P # 1 to P # 4 are respectively transmitted from physical antennas # 2, # 4, # 6 and # 8 of the second group. Has been sent.

  When the user equipment LTE-A_UE has been assigned resource blocks of both RB groups A and B, the reception status of four types of reference signals P # 1 to P # 4 in the resource blocks of each group should be measured Thus, the channel states relating to the physical antennas # 1, # 3, # 5 and # 7 and the channel states relating to the physical antennas # 2, # 4, # 6 and # 8 can be measured.

  When the resource block allocated to the user apparatus LTE-A_UE belongs only to RB group A (for example, RB1), the reference signals P # 1 to P # 4 extracted from the resource block are the base station apparatus The channel states for physical antennas # 1, # 3, # 5, and # 7 are shown. In step S23, the reception status regarding these physical antennas is measured. The user apparatus LTE-A_UE must also prepare a channel state related to another physical antenna (# 2, # 4, # 6, # 8). Therefore, the user apparatus LTE-A_UE extracts the reference signal of the resource block (for example, RB2) of the RB group B that is closest to the allocated resource block (RB1 in the current example). Since the reference signals P # 1 to P # 4 of resource blocks belonging to RB group B are transmitted from physical antennas # 2, # 4, # 6 and # 8, measure the reception status of these reference signals. Thus, the channel states relating to the physical antennas # 2, # 4, # 6, and # 8 can be measured. However, since this measurement value is not related to the allocated resource block, it is an approximate channel estimation value. Therefore, the user apparatus LTE-A_UE should select the resource block of RB group B that is closest to the allocated resource block (which belongs to RB group A in the current example). In addition to or as an alternative to selecting a resource block as close as possible, the measurement of the reception status of the reference signal may be interpolated. Interpolation may be extrapolation or interpolation.

  When the resource block assigned with the user equipment LTE-A_UE belongs only to the RB group B, the four types of reference signals P # 1 to P # 4 are the physical antennas # 2 and # 4 of the second group. , # 6 and # 8, respectively. Similarly to the above, user apparatus LTE-A_UE measures the channel state regarding the eight physical antennas by extracting the reference signal of the resource block of RB group A that is closest to the allocated resource block.

  In step S24, the downlink shared data signal is reproduced while using the channel estimation result for each of the eight antennas.

  In step S25, the measurement result of the reception status for 8 antennas and / or the acknowledgment signal (ACK / NACK) of the downlink shared data signal is transmitted to the base station apparatus.

  Even if the resource block is not allocated for the downlink shared data signal of the user apparatus LTE_UE, the user apparatus LTE_UE performs channel state measurement using the reference signals P # 1 to P # 4 as necessary, and performs measurement. The result may be reported to the base station apparatus. For example, user apparatus LTE_UE may measure a channel state about the resource block instruct | indicated from the base station apparatus, and may report a measurement result by PUCCH.

  According to this embodiment, four types of reference signals are mapped in the same arrangement pattern in any resource block. The control signal is demodulated using this reference signal. Therefore, regarding the control signal, the LTE user apparatus and the LTE-A user apparatus can restore the control signal in the same procedure. Further, the user equipment LTE-A_UE for LTE-A extracts all the eight physical antennas by extracting the reference signals from at least one resource block of RB group A and at least one resource block of RB group B, respectively. Can measure the radio channel status. Therefore, any resource block may be allocated to LTE_UE and LTE-A_UE.

  In addition, although the report of the channel state regarding each physical antenna may be performed for each resource block, an average value for several resource blocks is reported from the viewpoint of saving the amount of control information required for the report. Also good. Further, individual values or a total value of the upper predetermined number of resource blocks with good quality among the predetermined number of resource blocks may be reported to the base station apparatus. In the example shown in FIG. 6, one subband group (resource block group) is formed by five resource blocks, and the channel state may be reported for each subband group (that is, reported for each physical antenna). Needless to say.)

  In FIG. 6, RB groups A and B are changed for each subband size within the same subframe. The reference signals from the first group physical antennas (# 1, # 3, # 5, # 7) of the base station apparatus are also received from the second group physical antennas (# 1, # 3, # 5, # 7). A reference signal can also be acquired within one subframe. Therefore, the illustrated example is preferable in that the user apparatus LTE-A_UE for LTE-A can quickly measure the channel state.

< 2. Modified example (time direction) >
The configuration example of the downlink signal is not limited to that shown in FIG. 6, and various configuration examples can be considered. FIG. 9 shows an example in which the configuration of the downlink signal is changed for each subframe. In this example, the correspondence relationship between the reference signal arrangement pattern in the resource block and the physical antenna of the corresponding base station apparatus is the same if the subframes are the same. This is preferable from the viewpoint of simplification of signal processing (particularly, reduction of the burden of creating downstream signals). The user apparatus for LTE-A measures the channel state using the resource block of a certain subframe and the resource block of the previous and / or subsequent subframe. Although the measurement takes at least two subframe periods, it is preferable in that the same frequency band (indicated by RB1 and RB2 in the figure) can be measured for the first group of antennas and the second group of antennas. The configuration example shown in the figure is preferable when there is little time fluctuation of the channel state, for example, for a user who is moving only at a low speed.

< 3. Modified example (time and frequency direction) >
FIG. 10 shows an example in which the configuration of the downlink signal is changed for each subband and subframe. Since this example is a combination of the example shown in FIG. 6 and the example shown in FIG. 9, it is preferable in that at least the advantageous effects described above can be obtained. Furthermore, resource blocks with different RB groups can be obtained from the same subframe as well as from previous and subsequent subframes. Therefore, it is preferable for the user apparatus UTE-A_UE for LTE-A in that the number of appropriate resource block options with different RB groups increases. For example, in the case of RB1 in FIG. 10, appropriate resource blocks having different RB groups exist not only in the same subframe as in RB2, but also in the preceding subframe as in RB3.

  How the resource blocks having different RB groups are arranged in the downlink signal is not limited to the illustrated one, and any appropriate arrangement may be used. For example, as shown in FIG. 6 and FIG. 10, the RB group is not only changed for each subband, but may be changed for a plurality of subbands, or for each number of resource blocks different from the subbands. It may be changed. Similarly, the RB group may be changed not only for each subframe but also for each of a plurality of subframes.

< 4. Modified example (individual reference signal) >
In the above example, the same reference signals P # 1 to P # 4 are transmitted in any resource block of RB groups A and B. Thereby, any resource block can be allocated to the LTE user apparatus. Instead, the LTE-A user apparatus has to extract the reference signals P # 1 to P # 4 from at least two resource blocks with different RB groups and estimate the channel state for eight antennas. When all resource blocks allocated to the LET-A user apparatus belong to the same RB group, the user apparatus LTE-A_UE selects a resource block that has not been allocated (resource block belonging to a different RB group). The channel state for the remaining antennas must be estimated using the reference signal extracted therefrom. There is a concern about degradation of channel estimation accuracy in that a resource block different from the actually allocated resource block is used.

  On the other hand, when scheduling radio resources, the base station apparatus can know which user apparatus belongs to the LTE system and which user apparatus belongs to the LTE-A system.

  So, in this modification, when a base station apparatus allocates a resource block to an LTE user apparatus, the base station apparatus includes four types of reference signals P # 1 to P # 4 common to all users in the resource block. Furthermore, when the base station apparatus allocates resource blocks to the LTE-A user apparatus, the base station apparatus is not only unique to four types of reference signals P # 1 to P # 4 common to all users, but also specific to LTE-A users. The reference signals P # 5 to P # 8 are also included in the resource block.

  FIG. 11 shows resource blocks (left side) allocated to LTE user apparatuses and resource blocks (right side) allocated to LTE-A user apparatuses. The resource block on the left side is the same as that shown on the left side of FIG. The resource block (right side of FIG. 11) allocated to the user apparatus of the LTE-A system is not only the four types of reference signals P # 1 to P # 4 common to all users, but also a reference specific to the user of the LTE-A system. It also includes signals P # 5-P # 8. It should be noted that the arrangement pattern of the common reference signals P # 1 to P # 4 is kept the same on the left and right in FIG.

  FIG. 12 shows an example of the correspondence between the reference signals P # 1 to P # 8 and the physical antennas # 1 to # 8. In the illustrated example, reference signals P # 1, P # 2, P # 3, and P # 4 common to all users are transmitted from the physical antennas # 1, # 3, # 5, and # 7 of the first group, respectively. The Reference signals P # 5, P # 6, P # 7, and P # 8 unique to LTE-A users are transmitted from the second group of physical antennas # 2, # 4, # 6, and # 8, respectively. The correspondence relationship shown in FIG. 12 is merely an example, and any appropriate correspondence relationship or grouping of antennas may be performed. For example, the first group may be composed of # 1, # 2, # 3, and # 4 in ascending order, and the second group may be composed of # 5, # 6, # 7, and # 8. These correspondence relationships may be fixed in the system invariably, or may be changed regularly or irregularly.

  When a resource block as shown on the right side of FIG. 11 is allocated to a user apparatus of the LTE-A system, the channel state for 8 antennas is measured from the reference signals P # 1 to P # 8 in the resource block. Can do. Therefore, this modification is preferable from the viewpoint of increasing the measurement accuracy of the channel state.

< 5. Base station >
FIG. 13 shows a base station apparatus according to an embodiment of the present invention. The base station device includes a signal processing unit for LTE user devices and a signal processing unit for LTE-A user devices.

  The signal processing unit for LTE user apparatus includes a buffer 103b, a channel encoding unit 107b, a data modulation unit 109b, a precoding multiplication unit 111b, a common reference signal generation unit 114b, a reference signal multiplexing unit 115b, and a mapping control unit 116b.

  Similarly, the signal processing unit for the LTE-A user apparatus includes a buffer 103a, a channel coding unit 107a, a data modulation unit 109a, a precoding multiplication unit 111a, an individual reference signal generation unit 114a, a reference signal multiplexing unit 115a, and a mapping control unit. 116a.

  The scheduler 105 and the subcarrier mapping unit 113 are commonly used for signal processing units for LTE and LTE-A user apparatuses.

  Further, the base station apparatus includes an inverse fast Fourier transform (IFFT) unit 117, a cyclic prefix (CP) adding unit 119, and a radio unit (RF) for each of the eight physical antennas. Have. The base station apparatus includes eight transmission antennas, but the number of antennas may be eight or more.

  The LTE user apparatus buffer 103b stores transmission data for Nb LTE user apparatuses in the cell. The buffer 103a for the LTE-A user apparatus stores transmission data for Na LTE-A user apparatuses in the cell. The signals transmitted on the downlink include various signals such as a control signal, a shared data signal, and a reference signal. In this embodiment, the relationship between the reference signal and other signals is particularly important. For this reason, details of processing relating to the control signal and the shared data signal are omitted.

  The scheduler 105 manages radio resources used in the downlink. Under scheduling by the scheduler 105, resource blocks are allocated to the transmission data stored in the buffers 103a and 103b. Scheduling may be based on any suitable algorithm known in the art. As an example, scheduling may be performed based on a proportional fairness method.

  The channel coding unit 107b for LTE user equipment channel-codes transmission data. The channel coding unit 107a for the LTE-A user apparatus also performs channel coding of transmission data. The channel coding rate is instructed from a control unit (not shown). In this embodiment, since adaptive modulation and channel coding are used, the channel coding rate is appropriately changed according to the channel state (specifically, CQI) of the user apparatus. As an example, the channel coding rate may take a value such as 1/3 or 1/16. As the channel encoding method, any appropriate encoding method known in the art may be used. As an example, channel coding may be performed by turbo coding, convolutional coding, or the like.

  The data modulation unit 109b for LTE user apparatus performs data modulation on transmission data after channel coding. The data modulation unit 109a for LTE-A user apparatus also performs data modulation on transmission data after channel coding. The data modulation method is instructed from a control unit (not shown). In this embodiment, since adaptive modulation and channel coding are used, the data modulation is appropriately changed according to the channel state (specifically, CQI) of the user apparatus. Any appropriate data modulation scheme known in the art may be used as the data modulation scheme. As an example, the data modulation scheme may be BPSK, QPSK, 16QAM, 64QAM, or the like.

  Based on a precoding matrix indicator (PMI) fed back from the LTE user apparatus, the precoding multiplication unit 111b for LTE user apparatus multiplies transmission data by a precoding matrix. The LTE-A user apparatus precoding multiplier 111a also multiplies transmission data by a precoding matrix based on a precoding matrix indicator (PMI) fed back from the LTE-A user apparatus. The precoding matrix indicator may be any weight matrix group selected from a predetermined number of weight matrix groups. The predetermined number of weight matrix groups may be referred to as a code book. In addition, in the case of a cell for which precoding is not essential, these processes regarding precoding may be omitted.

  Subcarrier mapping section 113 maps transmission data to each subcarrier according to the resource allocation information from scheduler 103.

  The common reference signal generation unit 114b generates or stores common reference signals P # 1 to P # 4 that are commonly used by all users in the cell. In this embodiment, there are four types of common reference signals, but a larger number or a smaller number of common reference signals may be prepared. The common reference signal is commonly used for all users in the cell and is different for each cell, and may be referred to as a cell-specific RS (Cell-specific Reference Signal). The common reference signal may be expressed as an orthogonal code sequence or may be expressed as a non-orthogonal code sequence. From the viewpoint of reducing interference between users in the own cell, it is preferable to use an orthogonal code sequence.

  The individual reference signal generation unit 114a generates or stores reference signals P # 5 to P # 8 that are transmitted only to the LTE-A user apparatus. In this embodiment, there are four types of individual reference signals, but a larger number or a smaller number of common reference signals may be prepared. Since the dedicated reference signal is uniquely used in the LTE-A user apparatus, it may be referred to as a user-specific RS (UE-specific Reference Signal). The individual reference signal may also be represented by an orthogonal code sequence or a non-orthogonal code sequence. From the viewpoint of reducing interference between users in the own cell, it is preferable to use an orthogonal code sequence.

  The mapping control unit 116b related to the common reference signal provides a control signal to the reference signal multiplexing units 115a and 115b based on the correspondence relationship between the common reference signals P # 1 to P # 4 and the physical antennas # 1 to # 8. This control signal indicates how the common reference signal should be multiplexed into the resource block. As shown in the figure, it should be noted that the control signal indicating the common reference signal multiplexing method is provided to all the reference signal multiplexing units 115a and 115b. Thus, the arrangement pattern of the common reference signal in the resource block is maintained unchanged regardless of the resource block.

  The mapping control unit 116a related to the dedicated reference signal sends the control signal to the LTE-A reference signal multiplexing unit 115a based on the correspondence between the dedicated reference signals P # 5 to P # 8 and the physical antennas # 1 to # 8. give. This control signal indicates how the individual reference signal should be multiplexed into the resource block. As shown in the figure, it should be noted that the control signal indicating the multiplexing method of the individual reference signal is given only to the reference signal multiplexing unit 115a for LTE-A (in all the reference signal multiplexing units, Not given.) Thereby, individual reference signals P # 5 to P # 8 can be mapped only for the resource block of the LTE-A user apparatus.

  The reference signal multiplexing unit 115b for the LTE user apparatus multiplexes the transmission data and the common reference signal according to the control signal from the mapping control unit 116b regarding the common reference signal. The multiplexed resource block has a configuration as shown in FIG. 7 or FIG. 11 (left side). The LTE-A user apparatus reference signal multiplexing unit 115a also multiplexes the transmission data and the common reference signal according to the control signal from the mapping control unit 116b regarding the common reference signal. Further, the reference signal multiplexing unit 115a for the LTE-A user apparatus multiplexes the transmission data and the individual reference signal according to the control signal from the mapping control unit 116a regarding the individual reference signal. The multiplexed resource block has a configuration as shown in FIG. 11 (right side). When the dedicated reference signal is not used, the resource block for the LTE-A user apparatus has a configuration as shown in FIG. 7 or FIG. 11 (left side).

  Transmission data including a common reference signal and, if necessary, an individual reference signal is processed for each physical antenna so as to be transmitted from each physical antenna. In IFFT section 117, transmission data is subjected to fast inverse Fourier transform and converted to a symbol in the time domain.

  The cyclic prefix assignment unit (+ CP) 119 prepares a guard interval by using a part of the beginning or end of the symbol to be transmitted.

  The radio unit (RF) 121 performs processing such as digital-analog conversion, band limitation, frequency conversion, power amplification, and the like on the symbol with the guard interval to create a radio communication signal. The wireless communication signal is wirelessly transmitted from each antenna to the user apparatus.

< 6. User device >
FIG. 14 shows a user equipment according to an embodiment of the present invention. The user device is a user device used in the LTE-A system. As described above, the LTE user apparatus can be used similarly regardless of the presence or absence of the LTE-A system. The user equipment is typically a mobile station, but may be a fixed station. The illustrated user apparatus has N reception antennas corresponding to N transmission antennas (for example, eight transmission antennas) of the base station apparatus. The user apparatus includes a duplexer 201, a radio unit (RF) 203, and a fast Fourier transform unit (FFT) 207 for each of the eight physical antennas. Further, the user apparatus includes a reception timing estimation unit 205, a channel estimation unit 209 that uses a common reference signal, a broadcast information decoding unit 210, a control signal decoding unit 211, a channel estimation unit 212 that uses a dedicated reference signal, and a data channel detection unit 213. And a channel decoding unit 215.

  The duplexer 201 controls transmission / reception switching. In the case of the frequency division duplex (FDD) scheme, the duplexer may be configured with a filter that passes each of the transmission band and the reception band. In the case of the time division duplex (TDD) system, the duplexer may be composed of a simple switch.

  A radio unit (RF) 203 performs predetermined signal processing for converting a received signal received via a physical antenna and a duplexer into a baseband digital signal. This signal processing may include, for example, power amplification, band limiting, and analog-to-digital conversion.

  The reception timing estimation unit 205 estimates the reception timing of the reception signal. The estimation may be made by any suitable method known in the art. For example, if the correlation between the received OFDM symbol and the received OFDM symbol delayed by the effective symbol period is sequentially calculated, a high correlation value can be obtained over the guard interval (CP) period, and the symbol timing can be estimated.

  The FFT unit 207 performs a Fourier transform on the received signal based on the reception timing notified from the reception timing estimation unit 205. As a result, the received signal is converted into a signal in the frequency domain.

  Channel estimation section 209 extracts common reference signals P # 1 to P # 4 from the received signal, and measures the channel state for each physical antenna based on the common reference signal. By channel estimation, the phase rotation amount and amplitude fluctuation amount on the propagation path are determined, and the phase rotation amount and the like are used as a compensation amount when receiving subsequent signals.

  Broadcast information decoding section 210 extracts information transmitted on the broadcast channel (BCH) from the received signal, and demodulates and decodes it. The broadcast channel is transmitted from four specific physical antennas (for example, the first group) of the base station device. This is because broadcast information can be appropriately received by both the LTE user apparatus and the LTE-A user apparatus. In addition to general system information, the broadcast information includes a correspondence relationship between the common reference signal and the physical antenna (for example, FIG. 8) and a correspondence relationship between the individual reference signal and the physical antenna (for example, FIG. 12). ), Information indicating the arrangement pattern of the common / individual reference signal, the arrangement configuration of the RB group, and the like are also included in the broadcast information. In addition, it is not essential for this invention that these information is contained in alerting | reporting information, and may be contained in another channel. Alternatively, it may be fixed by the system so that signaling is unnecessary. However, from the viewpoint of efficiently notifying all users while making the correspondence relationship variable, it is preferable to include it in the notification information.

  The control signal decoding unit 211 demodulates and decodes information transmitted using the downlink control signal (particularly, PDCCH). The downlink control signal includes radio resource allocation information (downlink / uplink scheduling grant), and when the user apparatus has been allocated radio resources for the downlink shared data signal, the resource block to be used and the MCS (data modulation scheme) And channel coding rate) and the like are specified.

  Channel estimation section 212 extracts individual reference signals P # 5 to P # 8 from the received signal, and measures the channel state for each physical antenna based on the individual reference signal. By channel estimation, the phase rotation amount and amplitude fluctuation amount on the propagation path for the physical antennas # 5 to # 8 are determined, and the phase rotation amount and the like are used as a compensation amount in subsequent signal reception.

  When an individual reference signal is not used, reference signals are extracted from at least two resource blocks having different resource block configurations, and channel states for eight antennas are measured.

  Data channel detection section 213 demodulates data using the channel estimation results of channel estimation sections 209 and 212. Since the received signal is received in a state where the signals transmitted from the respective physical antennas are mixed, the received signal needs to be first separated into the signals transmitted from the individual physical antennas. Signal separation may be performed by any suitable algorithm known in the art. As an example, a zero forcing method, a minimum mean square error (MMSE) method, a maximum likelihood detection (MLD) method, or the like may be used. The signal of each antenna after the signal separation is data demodulated. Data demodulation is performed corresponding to the data modulation method performed on the transmission side.

  The channel decoding unit 215 decodes the data demodulated by the data channel detection unit 213 and reproduces the signal transmitted from the base station.

  Although the present invention has been described by taking the LTE system and the LTE-A system as examples, the present invention may be used in any appropriate situation where user apparatuses having different numbers of physical antennas are mixed. For example, the present invention may be applied to HSDPA / HSUPA W-CDMA systems, LTE systems, IMT-Advanced systems, WiMAX systems, Wi-Fi systems, and the like.

  Although the present invention has been described with reference to particular embodiments, they are merely exemplary and those skilled in the art will appreciate various variations, modifications, alternatives, substitutions, and the like. Although specific numerical examples have been described in order to facilitate understanding of the invention, these numerical values are merely examples and any appropriate values may be used unless otherwise specified. The division of the embodiment or item is not essential to the present invention, and the matters described in two or more embodiments or items may be used in combination as necessary, or may be described in a certain embodiment or item. Matters may apply to matters described in other examples or items (unless they conflict). For convenience of explanation, an apparatus according to an embodiment of the present invention has been described using a functional block diagram. However, such an apparatus may be implemented by hardware, software, or a combination thereof. The present invention is not limited to the above embodiments, and various modifications, modifications, alternatives, substitutions, and the like are included in the present invention without departing from the spirit of the present invention.

  Hereinafter, specific embodiments will be exemplified.

(Additional item 1)
A plurality of physical antennas including a first group of M physical antennas and a second group of M physical antennas;
A reference signal multiplexing unit that multiplexes at least M types of reference signals into resource blocks of downlink signals;
A transmitter for wirelessly transmitting the downlink signal;
The M types of reference signals are multiplexed on the first and second resource blocks in the same arrangement pattern,
M types of reference signals in the first resource block are transmitted from the physical antennas of the first group;
The base station apparatus configured to transmit M types of reference signals in the second resource block from the physical antennas of the second group.

(Appendix 2)
The base station apparatus according to supplementary note 1, wherein a correspondence relationship between the M types of reference signals and the M physical antennas in the first and second groups is notified to a user apparatus.

(Additional Item 3)
The base station apparatus according to supplementary note 2, wherein the first resource block and the second resource block are included in one time subframe.

(Appendix 4)
The base station apparatus according to supplementary note 3, wherein a predetermined plurality of first or second resource blocks are prepared adjacent to each other in the frequency direction.

(Appendix 5)
The base station apparatus according to supplementary note 2, wherein the first resource block is included in a certain time subframe, and the second resource block is included in a subsequent time subframe.

(Appendix 6)
The base station apparatus according to supplementary note 2, wherein the first resource block is included in a certain time subframe, and the second resource block is also included in the time subframe and another time subframe.

(Appendix 7)
The reference signal multiplexing unit converts the reference signal into a downlink signal so that a resource block of a specific user apparatus includes a P type reference signal different from the M type reference signals in addition to the M type reference signals. Item 3. The base station device according to item 2 to be multiplexed.

(Appendix 8)
A method used in a base station apparatus having a plurality of physical antennas including a first group of M physical antennas and a second group of M physical antennas,
A multiplexing step of multiplexing at least M types of reference signals into resource blocks of downlink signals;
A transmission step of wirelessly transmitting the downlink signal;
And the M types of reference signals are multiplexed on the first and second resource blocks in the same arrangement pattern,
M types of reference signals in the first resource block are transmitted from the physical antennas of the first group;
A method used in a base station apparatus in which M types of reference signals in the second resource block are transmitted from the physical antennas of the second group.

(Appendix 9)
A plurality of physical antennas including a first group of M physical antennas and a second group of M physical antennas;
A receiving unit for receiving M types of reference signals included in the first resource block and M types of reference signals included in the second resource block;
Using the reference signal in the first resource block, measure the channel state related to the physical antenna of the first group, and use the reference signal in the second resource block to relate to the physical antenna of the second group A measurement unit for measuring the channel state;
A user device.

(Appendix 10)
The base station apparatus according to supplementary note 9, wherein a correspondence relationship between the M types of reference signals and the M physical antennas in the first and second groups is reported from the base station apparatus.

(Appendix 11)
The base station apparatus according to supplementary note 10, wherein the first resource block and the second resource block are included in one time subframe.

(Appendix 12)
The base station apparatus according to Additional Item 11, wherein a predetermined plurality of first or second resource blocks are prepared adjacent to each other in the frequency direction.

(Appendix 13)
The base station apparatus according to supplementary note 10, wherein the first resource block is included in a certain time subframe, and the second resource block is included in a subsequent time subframe.

(Appendix 14)
The base station apparatus according to supplementary note 10, wherein the first resource block is included in a certain time subframe, and the second resource block is also included in the time subframe and another time subframe.

(Appendix 15)
The base station apparatus according to supplementary note 10, wherein a resource block allocated to the user apparatus includes a P type reference signal different from the M type reference signals in addition to the M type reference signals.

(Appendix 16)
A method used in a user equipment having a plurality of physical antennas including a first group of M physical antennas and a second group of M physical antennas, comprising:
A receiving step of receiving M types of reference signals included in the first resource block and M types of reference signals included in the second resource block;
Measure a channel state relating to the first group of physical antennas using a reference signal in the first resource block, and measure a channel state relating to the second group of physical antennas using a reference signal in the second resource block. Measuring step to
A method used in a user device having:

103a, 103b buffer
105 Scheduler
107a, 107b channel coding section
109a, 109b Data modulation section
111a, 111b precoding multiplier
113 Subcarrier mapping section
114a Individual reference signal generator
114b Common reference signal generator
115a, 115b Reference signal multiplexer
117 IFFT
119 CP grant department
121 Radio section
201 Duplexer
203 Radio section
205 Reception timing estimator
207 FFT section
209 Channel estimation unit (common RS)
210 Broadcast information decoder (BCH)
211 Control signal decoder (PDCCH)
212 Channel estimation unit (individual RS)
213 Data channel detector
215 Channel decoder

Claims (6)

A first antenna group corresponding to the first reference signal group;
A second antenna group corresponding to the second reference signal group;
For each of a plurality of resource blocks included in a downlink signal, a reference signal belonging to the first reference signal group is multiplexed in the same arrangement pattern, and among the plurality of resource blocks, a resource block that is allocated to a specific user apparatus, A reference signal multiplexing unit that multiplexes reference signals belonging to the second reference signal group in another arrangement pattern different from the arrangement pattern;
And a transmission unit that transmits the downlink signal using the first and second antenna groups.   The base station according to claim 1, wherein the downlink signal includes the first or second reference signal group, a shared data signal, and a control signal indicating allocation information of a resource block in the shared data signal.   The base station according to claim 1 or 2, wherein a correspondence relationship between the first and second reference signal groups and the first and second antenna groups is changed regularly or irregularly. A processing method executed by a base station having a first antenna group corresponding to a first reference signal group and a second antenna group corresponding to a second reference signal group,
The reference signal multiplexing unit multiplexes the reference signals belonging to the first reference signal group with the same arrangement pattern for each of the plurality of resource blocks included in the downlink signal, and transmits the reference signal to a specific user apparatus among the plurality of resource blocks. For the resource block to be allocated, the step of multiplexing the reference signals belonging to the second reference signal group with another arrangement pattern different from the arrangement pattern;
And a transmission unit transmitting the downlink signal using the first and second antenna groups.   5. The processing method according to claim 4, wherein the downlink signal includes the first or second reference signal group, a shared data signal, and a control signal indicating resource allocation information in the shared data signal.   6. The processing method according to claim 4, wherein a correspondence relationship between the first and second reference signal groups and the first and second antenna groups is changed regularly or irregularly.

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