WO2020138003A1

WO2020138003A1 - Base station device, terminal device, and communication method

Info

Publication number: WO2020138003A1
Application number: PCT/JP2019/050423
Authority: WO
Inventors: 良太山田; 泰弘浜口
Original assignee: シャープ株式会社; 鴻穎創新有限公司
Priority date: 2018-12-26
Filing date: 2019-12-23
Publication date: 2020-07-02
Also published as: JP2020107951A

Abstract

Provided are a base station device, a terminal device, and a communication method that make efficient communication possible while suppressing increases in channel state information (CSI) when communicating using multiple antennas. The terminal device, which communicates with the base station device, comprises: a reception unit which receives a CSI report configuration and a CSI reference signal (CSI-RS); a CSI measurement unit which uses the CSI-RS to obtain CSI; and a transmission unit which transmits said CSI to the base station device. The CSI report configuration includes a codebook configuration that configures a type-1 codebook or a type-2 codebook, and when a type-2 codebook is configured by the codebook configuration, the CSI includes one among a type-1 CSI based on the type-1 codebook and a type-2 CSI based on the type-2 codebook.

Description

Base station device, terminal device, and communication method

The present invention relates to a base station device, a terminal device, and a communication method. The present application claims priority based on Japanese Patent Application No. 2018-242662 filed in Japan on December 26, 2018, the contents of which are incorporated herein by reference.

Aiming to start commercial services around 2020, research and development activities regarding 5th generation mobile radio communication systems (5G systems) are being actively conducted. Recently, the International Telecommunications Union Radiocommunications Sector (ITU-R), which is an international standardization organization, has issued a vision recommendation regarding the 5G system standard method (International mobile telecommunication-2020-and-beyond: IMT-2020). Reported (see Non-Patent Document 1).

Securing frequency resources is an important issue for communication systems to cope with the rapid increase in data traffic. Therefore, in 5G, one of the targets is to realize ultra-large capacity communication by using a higher frequency band than the frequency band (frequency band) used in LTE (Long term evolution). However, in wireless communication using a high frequency band, path loss becomes a problem. In order to compensate for path loss, beamforming precoding with a large number of antennas is a promising technology (see Non-Patent Document 2).

When communicating using multiple antennas, the terminal device needs to feed back the channel state information to the base station device. Especially when spatial multiplexing such as multi-user MIMO is applied, it is desirable that the channel state information has high accuracy. However, the highly accurate channel state information has a large amount of information, and its overhead may be a problem.

One aspect of the present invention has been made in view of such circumstances, and an object thereof is a base capable of performing efficient communication while suppressing an increase in channel state information when communicating using multiple antennas. It is to provide a station device, a terminal device, and a communication method.

The configurations of a base station device, a terminal device, and a communication method according to an aspect of the present invention in order to solve the above problems are as follows.

A terminal device according to an aspect of the present invention is a terminal device that communicates with a base station device, and a receiving unit that receives a channel state information (CSI) report setting and a channel state information reference signal (CSI-RS). A CSI measuring unit that obtains CSI using the CSI-RS and a transmitting unit that transmits the CSI to the base station apparatus are provided, and the CSI report setting sets a type 1 codebook or a type 2 codebook. When the type 2 codebook is set by the codebook setting including the codebook setting, the CSI is either a type 1 CSI based on the type 1 codebook or a type 2 CSI based on the type 2 codebook. Including.

Further, in the terminal device according to an aspect of the present invention, the CSI includes a CSI part 1 and a CSI part 2, and the CSI part 1 includes information indicating whether the CSI part 2 includes the type 1 CSI. , If the CSI part 1 reports that it contains type 1 CSI, the CSI part 2 reports type 1 CSI, and if the CSI part 1 reports that it contains type 2 CSI, the CSI part 2 reports type 2 CSI. To report.

Further, in the terminal device according to an aspect of the present invention, the type 1 codebook is provided with at least one vector and a precoding matrix per layer with a phase coefficient, and the type 2 codebook is at least a plurality of orthogonal vectors. , A wideband amplitude coefficient, and a subband phase coefficient, a precoding matrix per layer is given, and the CSI part 1 includes information indicating the number of nonzero wideband amplitude coefficients, and the nonzero wideband amplitude coefficient. The information indicating the number of coefficients indicates whether or not the CSI part 2 includes the type 1 CSI.

In the terminal device according to one aspect of the present invention, the type 2 CSI includes a PMI compressed in the frequency domain.

In addition, in the terminal device according to one aspect of the present invention, whether to report the type 1 CSI or the type 2 CSI is selected based on a channel quality index (CQI).

A base station device according to one aspect of the present invention is a base station device that communicates with a terminal device, and is a transmission unit that transmits a channel state information (CSI) report setting and a channel state information reference signal (CSI-RS). And a receiving unit for receiving the CSI from the terminal device, the CSI report setting includes a codebook setting for setting a type 1 codebook or a type 2 codebook, and the type 2 is set in the codebook setting. When a codebook is set, the CSI includes one of a type-1 CSI based on the type-1 codebook and a type-2 CSI based on the type-2 codebook.

In the base station device according to one aspect of the present invention, the CSI includes a CSI part 1 and a CSI part 2, and the CSI part 1 includes information indicating whether the CSI part 2 includes the type 1 CSI. If the CSI part 1 receives the type 1 CSI, the CSI part 2 receives the type 1 CSI, and if the CSI part 1 receives the type 2 CSI, the CSI part 2 receives the type 2 CSI. To receive.

Further, in the base station apparatus according to an aspect of the present invention, the type 1 codebook is given a precoding matrix per layer by at least one vector and a phase coefficient, and the type 2 codebook is at least a plurality of orthogonal patterns. Given a precoding matrix per layer with a vector, a wideband amplitude coefficient, and a subband phase coefficient, the CSI part 1 includes information indicating the number of nonzero wideband amplitude coefficients, the nonzero wideband The information indicating the number of amplitude coefficients indicates whether the CSI part 2 includes the type 1 CSI.

Also, in the base station apparatus according to one aspect of the present invention, the type 2 CSI includes a PMI compressed in the frequency domain.

A communication method according to an aspect of the present invention is a communication method in a terminal device that communicates with a base station device, and receives a channel state information (CSI) report setting and a channel state information reference signal (CSI-RS). A CSI using the CSI-RS, and a step of transmitting the CSI to the base station apparatus. The CSI report setting sets a type 1 codebook or a type 2 codebook. When the type 2 codebook is set by the codebook setting including the codebook setting, the CSI is either a type 1 CSI based on the type 1 codebook or a type 2 CSI based on the type 2 codebook. Including.

A communication method according to an aspect of the present invention is a communication method in a base station device that communicates with a terminal device, and transmits a channel state information (CSI) report setting and a channel state information reference signal (CSI-RS). And a step of receiving the CSI from the terminal device, wherein the CSI report setting includes a codebook setting for setting a type 1 codebook or a type 2 codebook, and the type 2 is set in the codebook setting. When a codebook is set, the CSI includes one of a type-1 CSI based on the type-1 codebook and a type-2 CSI based on the type-2 codebook.

According to one aspect of the present invention, it is possible to efficiently reduce the amount of channel state information in multiple antennas.

It is a figure which shows the example of the communication system which concerns on this embodiment. It is a block diagram which shows the structural example of the base station apparatus which concerns on this embodiment. It is a block diagram which shows the structural example of the terminal device which concerns on this embodiment. It is a figure which shows the example of the communication system which concerns on this embodiment. It is a figure which shows an example of the type 1 codebook of 1 layer which concerns on this embodiment. It is a figure which shows an example of the type 1 codebook of 2 layers which concerns on this embodiment. It is a figure which shows an example of the candidate of the amplitude coefficient of the type 2 codebook which concerns on this embodiment. It is a figure which shows an example of the candidate of the phase coefficient of the type 2 codebook which concerns on this embodiment.

The communication system according to the present embodiment includes base station devices (transmission device, cell, transmission point, transmission antenna group, transmission antenna port group, component carrier, eNodeB, transmission point, transmission/reception point, transmission panel, access point, subarray) and terminals. The device (terminal, mobile terminal, receiving point, receiving terminal, receiving device, receiving antenna group, receiving antenna port group, UE, receiving point, receiving panel, station, subarray) is provided. A base station device connected to a terminal device (establishing a wireless link) is called a serving cell.

The base station device and the terminal device according to the present embodiment can communicate in a frequency band that requires a license (license band) and/or a frequency band that does not require a license (unlicensed band).

In this embodiment, “X/Y” includes the meaning of “X or Y”. In the present embodiment, “X/Y” includes the meanings of “X and Y”. In the present embodiment, “X/Y” includes the meaning of “X and/or Y”.

FIG. 1 is a diagram showing an example of a communication system according to the present embodiment. As shown in FIG. 1, the communication system in this embodiment includes a base station device 1A and a terminal device 2A. Further, the coverage 1-1 is a range (communication area) in which the base station device 1A can be connected to the terminal device. The base station device 1A is also simply referred to as a base station device. The terminal device 2A is also simply referred to as a terminal device.

In FIG. 1, the following uplink physical channels are used in the uplink wireless communication from the terminal device 2A to the base station device 1A. The uplink physical channel is used to transmit the information output from the upper layer.
・PUCCH (Physical Uplink Control Channel)
・PUSCH (Physical Uplink Shared Channel)
・PRACH (Physical Random Access Channel)

PUCCH is used to transmit uplink control information (Uplink Control Information: UCI). Here, the uplink control information includes ACK (apositive acknowledgment) or NACK (a negative acknowledgment) (ACK/NACK) for downlink data (downlink transport block, downlink-shared channel: DL-SCH). ACK/NACK for downlink data is also referred to as HARQ-ACK and HARQ feedback.

Also, the uplink control information includes channel state information (Channel State Information: CSI) for the downlink. In addition, the uplink control information includes a scheduling request (Scheduling Request: SR) used to request resources of an uplink shared channel (Uplink-Shared Channel: UL-SCH). The channel state information includes a rank index RI (Rank Indicator) that specifies a suitable spatial multiplexing number, a precoding matrix index PMI (Precoding Matrix Indicator) that specifies a suitable precoder, and a channel quality index CQI that specifies a suitable transmission rate. (Channel Quality Indicator), CSI-RS (Reference Signal) indicating a suitable CSI-RS resource, Resource Index CRI (CSI-RS Resource Indicator), CSI-RS or SS (Synchronization Signal) RSRP (Reference Signal Received Power) is applicable.

The channel quality index CQI (hereinafter, CQI value) may be a suitable modulation scheme (eg, QPSK, 16QAM, 64QAM, 256QAM, etc.) in a predetermined band (details will be described later) and a coding rate. it can. The CQI value can be an index (CQI Index) determined by the modulation method or the coding rate. The CQI value can be set in advance in the system.

The CRI indicates a CSI-RS resource having a preferable reception power/reception quality from a plurality of CSI-RS resources.

Note that the rank index and the precoding quality index can be set in advance by the system. The rank index or the precoding matrix index may be an index determined by the spatial multiplexing number or precoding matrix information. In addition, a part or all of the CQI value, PMI value, RI value and CRI value are also collectively referred to as a CSI value.

PUSCH is used to transmit uplink data (uplink transport block, UL-SCH). The PUSCH may also be used to send ACK/NACK and/or channel state information with the uplink data. Moreover, PUSCH may be used for transmitting only uplink control information.

PUSCH is also used to send RRC messages. The RRC message is information/signal processed in the radio resource control (Radio Resource Control: RRC) layer. PUSCH is also used to transmit MAC CE (Control Element). Here, the MAC CE is information/signal processed (transmitted) in the medium access control (MAC: Medium Access Control) layer.

For example, the power headroom may be included in MAC CE and reported via PUSCH. That is, the MAC CE field may be used to indicate the power headroom level.

PRACH is used to send a random access preamble.

Also, in uplink wireless communication, an uplink reference signal (ULRS) is used as an uplink physical signal. The uplink physical signal is not used to transmit the information output from the upper layer, but is used by the physical layer. Here, the uplink reference signal includes DMRS (Demodulation Reference Signal), SRS (Sounding Reference Signal), and PT-RS (Phase-Tracking reference signal).

DMRS is related to the transmission of PUSCH or PUCCH. For example, the base station device 1A uses DMRS to perform channel correction of PUSCH or PUCCH. For example, the base station device 1A uses SRS to measure the uplink channel state. The SRS is used for uplink observation (sounding). PT-RS is also used to compensate for phase noise. Note that the uplink DMRS is also called an uplink DMRS.

In FIG. 1, the following downlink physical channels are used in downlink radio communication from the base station apparatus 1A to the terminal apparatus 2A. The downlink physical channel is used to transmit information output from the upper layer.
・PBCH (Physical Broadcast Channel)
・PCFICH (Physical Control Format Indicator Channel)
・PHICH (Physical Hybrid automatic repeat request Indicator Channel)
-PDCCH (Physical Downlink Control Channel)
-EPDCCH (Enhanced Physical Downlink Control Channel)
PDSCH (Physical Downlink Shared Channel)

PBCH is used to notify the master information block (Master Information Block: MIB, Broadcast Channel: BCH) that is commonly used by terminal devices. The PCFICH is used to transmit information indicating an area used for transmitting the PDCCH (for example, the number of OFDM (Orthogonal Frequency Division Multiplexing) symbols). The MIB is also called minimum system information.

PHICH is used to transmit ACK/NACK for the uplink data (transport block, codeword) received by the base station device 1A. That is, PHICH is used to transmit a HARQ indicator (HARQ feedback) indicating ACK/NACK for uplink data. ACK/NACK is also referred to as HARQ-ACK. The terminal device 2A notifies the upper layer of the received ACK/NACK. ACK/NACK is ACK indicating that the data was correctly received, NACK indicating that the data was not received correctly, and DTX indicating that there was no corresponding data. When there is no PHICH for the uplink data, the terminal device 2A notifies the upper layer of ACK.

The PDCCH and EPDCCH are used to transmit downlink control information (Downlink Control Information: DCI). Here, a plurality of DCI formats are defined for transmission of downlink control information. That is, a field for downlink control information is defined in the DCI format and mapped to information bits.

For example, as the DCI format for the downlink, the DCI format 1A used for scheduling one PDSCH (transmission of one downlink transport block) in one cell is defined.

For example, the DCI format for the downlink includes downlink control information such as information about PDSCH resource allocation, information about MCS (Modulation and Coding Scheme) for PDSCH, and TPC command for PUCCH. Here, the DCI format for the downlink is also referred to as a downlink grant (or downlink assignment).

Further, for example, as the DCI format for the uplink, DCI format 0 used for scheduling one PUSCH (transmission of one uplink transport block) in one cell is defined.

For example, the DCI format for the uplink includes uplink control information such as information about PUSCH resource allocation, information about MCS for PUSCH, and TPC command for PUSCH. The DCI format for the uplink is also called an uplink grant (or uplink assignment).

Also, the DCI format for the uplink can be used for requesting (CSI request) downlink channel state information (CSI; Channel State Information; also referred to as reception quality information).

Also, the DCI format for the uplink can be used for setting the uplink resource that maps the channel state information report (CSI feedback report) that the terminal device feeds back to the base station device. For example, the channel state information report can be used for setting indicating an uplink resource for periodically reporting channel state information (Periodic CSI). The channel state information report can be used for mode setting (CSI report mode) for periodically reporting channel state information.

For example, the channel state information report can be used for setting indicating the uplink resource that reports irregular channel state information (Aperiodic CSI). The channel state information report can be used for mode setting (CSI report mode) in which channel state information is reported irregularly.

For example, the channel state information report can be used for setting the uplink resource that reports the semi-persistent channel state information (semi-persistent CSI). The channel state information report can be used for mode setting (CSI report mode) for semi-permanently reporting channel state information. The semi-persistent CSI report is a CSI report that is periodically issued during a period in which the upper layer signal or the downlink control information is activated and then deactivated.

Also, the DCI format for the uplink can be used for setting indicating the type of channel state information report that the terminal device feeds back to the base station device. The types of channel state information reports include wideband CSI (for example, Wideband CQI) and narrowband CSI (for example, Subband CQI).

When the PDSCH resource is scheduled using the downlink assignment, the terminal device receives the downlink data on the scheduled PDSCH. Further, when the PUSCH resource is scheduled using the uplink grant, the terminal device transmits the uplink data and/or the uplink control information on the scheduled PUSCH.

PDSCH is used to transmit downlink data (downlink transport block, DL-SCH). The PDSCH is also used to transmit the system information block type 1 message. The system information block type 1 message is cell-specific (cell-specific) information.

PDSCH is also used to send a system information message. The system information message includes a system information block X other than the system information block type 1. The system information message is cell-specific (cell-specific) information.

PDSCH is also used to send RRC messages. Here, the RRC message transmitted from the base station device may be common to a plurality of terminal devices in the cell. Further, the RRC message transmitted from the base station device 1A may be a dedicated message (also referred to as dedicated signaling) for a certain terminal device 2A. That is, the user device specific (user device specific) information is transmitted to a certain terminal device using a dedicated message. PDSCH is also used to transmit MAC CE.

Here, the RRC message and/or the MAC CE are also referred to as higher layer signaling.

PDSCH can also be used to request downlink channel state information. Moreover, PDSCH can be used for transmitting the uplink resource which maps the channel state information report (CSI feedback report) which a terminal device feeds back to a base station apparatus. For example, the channel state information report can be used for setting indicating an uplink resource for periodically reporting channel state information (Periodic CSI). The channel state information report can be used for mode setting (CSI report mode) for periodically reporting channel state information.

There are two types of downlink channel state information reports: wideband CSI (eg Wideband CSI) and narrowband CSI (eg Subband CSI). The wideband CSI calculates one channel state information for the system band of the cell. The narrowband CSI divides the system band into predetermined units, and calculates one channel state information for the division.

Also, in downlink wireless communication, a synchronization signal (Synchronization signal: SS) and a downlink reference signal (Downlink Reference Signal: DL) RS are used as downlink physical signals. The downlink physical signal is not used to transmit the information output from the upper layer, but is used by the physical layer. The synchronization signals include a primary synchronization signal (PrimarySynchronizationSignal:PSS) and a secondary synchronization signal (SecondarySynchronizationSignal: SSS).

-The synchronization signal is used by the terminal device to synchronize the downlink frequency domain and time domain. The synchronization signal is also used to measure the reception power, reception quality, or signal-to-interference and noise power ratio (SINR). Note that the received power measured with the sync signal is SS-RSRP (Synchronization Signal-Reference Reference Signal Received Power), the received quality measured with the sync signal is SS-RSRQ (Reference Signal Received Quality), and the SINR measured with the sync signal is SS- Also called SINR. SS-RSRQ is the ratio of SS-RSRP and RSSI. RSSI (Received Signal Strength Indicator) is the total average received power during a certain observation period. Further, the synchronization signal/downlink reference signal is used by the terminal device to perform propagation path correction of the downlink physical channel. For example, the synchronization signal/downlink reference signal is used by the terminal device to calculate downlink channel state information.

Here, the downlink reference signal includes DMRS (Demodulation Reference Signal; demodulation reference signal), NZP CSI-RS (Non-Zero Power Channel State Information Information-Reference Signal), ZP CSI-RS (Zero Power Channel State Information Information Reference Signal), PT-RS, TRS (Tracking Reference Signal). The downlink DMRS is also called a downlink DMRS. In the following embodiments, when simply referring to CSI-RS, it includes NZP CSI-RS and/or ZP CSI-RS.

DMRS is transmitted in the subframe and band used for transmission of PDSCH/PBCH/PDCCH/EPDCCH related to DMRS, and is used to demodulate PDSCH/PBCH/PDCCH/EPDCCH related to DMRS.

The resource of NZP CSI-RS is set by the base station device 1A. For example, the terminal device 2A performs signal measurement (channel measurement) or interference measurement using NZP CSI-RS. The NZP CSI-RS is used for beam scanning to search for a suitable beam direction, beam recovery for recovery when the received power/reception quality in the beam direction is deteriorated, and the like. The ZP CSI-RS resource is set by the base station device 1A. The base station device 1A transmits ZP CSI-RS with zero output. For example, the terminal device 2A measures interference in the resource corresponding to ZP CSI-RS. The resource for interference measurement supported by ZP CSI-RS is also called CSI-IM (Interference Measurement) resource.

The base station device 1A transmits (sets) the NZP CSI-RS resource setting for the NZP CSI-RS resource. The NZP CSI-RS resource setting includes one or a plurality of NZP CSI-RS resource mappings, CSI-RS resource setting ID of each NZP CSI-RS resource, and part or all of the number of antenna ports. The CSI-RS resource mapping is information (for example, resource element) indicating the OFDM symbol and subcarrier in the slot in which the CSI-RS resource is arranged. The CSI-RS resource setting ID is used to specify the NZP CSI-RS resource.

The base station device 1A transmits (sets) the CSI-IM resource setting. The CSI-IM resource settings include one or more CSI-IM resource mappings, CSI-IM resource setting IDs for each CSI-IM resource. The CSI-IM resource mapping is information (for example, resource element) indicating the OFDM symbol and subcarrier in the slot where the CSI-IM resource is arranged. The CSI-IM resource setting ID is used to identify the CSI-IM setting resource.

Also, CSI-RS is used to measure received power, received quality, or SINR. The reception power measured by CSI-RS is also called CSI-RSRP, the reception quality measured by CSI-RS is called CSI-RSRQ, and the SINR measured by CSI-RS is also called CSI-SINR. CSI-RSRQ is the ratio of CSI-RSRP and RSSI.

Also, the CSI-RS is transmitted regularly/non-periodically/semi-permanently.

Regarding CSI, the terminal device is set in the upper layer. For example, there are a CSI report setting that is a CSI report setting, a CSI resource setting that is a resource setting for measuring CSI, and a measurement link setting that links the CSI report setting and the CSI resource setting for CSI measurement. Also, one or more report settings, resource settings, and measurement link settings are set.

The CSI report setting includes a part or all of the report setting ID, the report setting type, the codebook setting, the CSI report amount, and the block error rate target. The Report Setting ID is used to identify the CSI Report Setting. The report setting type indicates a periodic/aperiodic/semi-permanent CSI report. The CSI report amount indicates the amount (value, type) to be reported, and is, for example, part or all of CRI, RI, PMI, CQI, or RSRP. The block error rate target is a target of the block error rate assumed when calculating the CQI. Further, the codebook setting includes the setting of the type 1 codebook or the type 2 codebook.

The CSI resource configuration includes a resource configuration ID, a synchronization signal block resource measurement list, a resource configuration type, a part or all of one or more resource set configurations. The resource setting ID is used to identify the resource setting. The synchronization signal block resource setting list is a list of resources for which measurement using the synchronization signal is performed. The resource configuration type indicates whether the CSI-RS is transmitted regularly, irregularly or semi-permanently. In addition, in the case where the CSI-RS is set to be transmitted semi-permanently, the CSI-RS is periodically transmitted during the period from the activation to the deactivation of the upper layer signal or the downlink control information. ..

The CSI-RS resource set setting includes a part or all of information indicating the CSI-RS resource set setting ID, resource repetition, and one or more CSI-RS resources. The resource set setting ID is used to specify the CSI-RS resource set setting. Resource repetition indicates ON/OFF of resource repetition in the resource set. When resource repetition is ON, it means that the base station apparatus uses a fixed (same) transmission beam for each of the plurality of CSI-RS resources in the resource set. In other words, when resource repetition is ON, the terminal device assumes that the base station device uses a fixed (same) transmission beam for each of the plurality of CSI-RS resources in the resource set. When the resource repetition is OFF, it means that the base station apparatus does not use a fixed (same) transmission beam for each of the plurality of CSI-RS resources in the resource set. In other words, when the resource repetition is OFF, the terminal device assumes that the base station device does not use a fixed (same) transmission beam for each of the plurality of CSI-RS resources in the resource set. The information indicating the CSI-RS resource includes one or more CSI-RS resource setting IDs and one or more CSI-IM resource setting IDs.

The measurement link setting includes a part or all of the measurement link setting ID, the report setting ID, and the resource setting ID, and the CSI report setting and the CSI resource setting are linked. The measurement link setting ID is used to specify the measurement link setting.

PT-RS is associated with DMRS (DMRS port group). The number of antenna ports of PT-RS is 1 or 2, and each PT-RS port is associated with a DMRS port group. Further, the terminal device assumes that the PT-RS port and the DMRS port are QCL with respect to delay spread, Doppler spread, Doppler shift, average delay, and spatial reception (Rx) parameter. The base station device sets the PT-RS setting with the signal of the upper layer. When the PT-RS setting is set, the PT-RS may be transmitted. The PT-RS is not transmitted in the case of a predetermined MCS (for example, when the modulation scheme is QPSK). Further, as the PT-RS setting, time density and frequency density are set. The time density indicates a time interval in which the PT-RS is arranged. Time density is shown as a function of scheduled MCS. The time density also includes the absence of PT-RS (not transmitted). The frequency density indicates a frequency interval in which PT-RSs are arranged. Frequency density is shown as a function of scheduled bandwidth. The frequency density also includes the absence of PT-RS (not transmitted). When the time density or the frequency density indicates that the PT-RS does not exist (is not transmitted), the PT-RS does not exist (is not transmitted).

MBSFN (Multimedia Broadcast multicast service Single Frequency Network) RS is transmitted in all bands of subframes used for PMCH transmission. MBSFN RS is used to demodulate PMCH. PMCH is transmitted at the antenna port used for transmitting MBSFN RS.

Here, the downlink physical channel and the downlink physical signal are collectively referred to as a downlink signal. Further, the uplink physical channel and the uplink physical signal are collectively referred to as an uplink signal. Further, the downlink physical channel and the uplink physical channel are collectively referred to as a physical channel. Further, the downlink physical signal and the uplink physical signal are collectively referred to as a physical signal.

Moreover, BCH, UL-SCH and DL-SCH are transport channels. The channel used in the MAC layer is called a transport channel. The unit of the transport channel used in the MAC layer is also called a transport block (Transport Block: TB) or a MAC PDU (Protocol Data Unit). The transport block is a unit of data that is delivered (delivered) by the MAC layer to the physical layer. In the physical layer, transport blocks are mapped to codewords, and an encoding process or the like is performed for each codeword.

In addition, for a terminal device that supports carrier aggregation (CA; Carrier Aggregation), the base station device can integrate and communicate with multiple component carriers (CCs) for more broadband transmission. .. In carrier aggregation, one primary cell (PCell; Primary Cell) and one or more secondary cells (SCell; Secondary Cell) are set as a set of serving cells.

In dual connectivity (DC; Dual Connectivity), a master cell group (MCG; Master Cell Group) and a secondary cell group (SCG; Secondary Cell Group) are set as groups of serving cells. The MCG is composed of a PCell and optionally one or more SCells. The SCG is composed of a primary SCell (PSCell) and optionally one or more SCells.

The base station device can communicate using wireless frames. The radio frame is composed of a plurality of subframes (subsections). When the frame length is expressed in time, for example, the radio frame length can be 10 milliseconds (ms) and the subframe length can be 1 ms. In this example, the radio frame is composed of 10 subframes.

Also, a slot is composed of 14 OFDM symbols. Since the OFDM symbol length may change depending on the subcarrier spacing, the slot length may change at the subcarrier spacing. A minislot is composed of fewer OFDM symbols than slots. Slots/minislots can be scheduling units. Note that the terminal device can know slot-based scheduling/minislot-based scheduling from the position (arrangement) of the first downlink DMRS. In slot-based scheduling, the first downlink DMRS is placed in the third or fourth symbol of the slot. In minislot-based scheduling, the first downlink DMRS is arranged in the first symbol of scheduled data (resource, PDSCH). The slot-based scheduling is also called PDSCH mapping type A. Minislot based scheduling is also called PDSCH mapping type B.

Also, a resource block is defined by 12 consecutive subcarriers. A resource element is defined by a frequency domain index (for example, a subcarrier index) and a time domain index (for example, an OFDM symbol index). Resource elements are classified as uplink resource elements, downlink element, flexible resource elements, and reserved resource elements. In the reserved resource element, the terminal device does not transmit the uplink signal and does not receive the downlink signal.

Also, multiple subcarrier spacing (SCS) are supported. For example, the SCS is 15/30/60/120/240/480 kHz.

Base station device/terminal device can communicate in licensed band or unlicensed band. The base station apparatus/terminal apparatus can communicate with at least one SCell operating in the unlicensed band by carrier aggregation, with the license band being PCell. In addition, the base station device/terminal device can perform dual connectivity communication in which the master cell group communicates in the license band and the secondary cell group communicates in the unlicensed band. Further, the base station device/terminal device can communicate only with PCell in the unlicensed band. Further, the base station device/terminal device can communicate with CA or DC only in the unlicensed band. It should be noted that that the license band is the PCell and the cell (SCell, PSCell) in the unlicensed band is assisted and communicated with, for example, CA or DC is also referred to as LAA (Licensed-Assisted Access). In addition, the communication of the base station device/terminal device only in the unlicensed band is also called unlicensed stand-alone access (ULSA). In addition, the communication of the base station device/terminal device only in the license band is also referred to as licensed access (LA).

FIG. 2 is a schematic block diagram showing the configuration of the base station device in this embodiment. As shown in FIG. 2, the base station device includes an upper layer processing unit (upper layer processing step) 101, a control unit (control step) 102, a transmission unit (transmission step) 103, a reception unit (reception step) 104, and a transmission/reception antenna. 105 and a measuring unit (measuring step) 106. The upper layer processing unit 101 includes a radio resource control unit (radio resource control step) 1011 and a scheduling unit (scheduling step) 1012. In addition, the transmission unit 103 includes a coding unit (coding step) 1031, a modulation unit (modulation step) 1032, a downlink reference signal generation unit (downlink reference signal generation step) 1033, a multiplexing unit (multiplexing step) 1034, a radio. A transmitter (wireless transmission step) 1035 is included. The receiving unit 104 includes a wireless receiving unit (wireless receiving step) 1041, a demultiplexing unit (demultiplexing step) 1042, a demodulating unit (demodulating step) 1043, and a decoding unit (decoding step) 1044.

The upper layer processing unit 101 is a medium access control (Medium Access Control: MAC) layer, a packet data integration protocol (Packet Data Convergence Protocol: PDCP) layer, a radio link control (Radio Link Control: RLC) layer, a radio resource control (Radio). Resource Control:RRC) layer processing. Further, upper layer processing section 101 generates information necessary for controlling transmitting section 103 and receiving section 104 and outputs it to control section 102.

The upper layer processing unit 101 receives information about the terminal device such as the function (UE capability) of the terminal device from the terminal device. In other words, the terminal device transmits its own function to the base station device as an upper layer signal.

Note that in the following description, the information about the terminal device includes information indicating whether the terminal device supports a predetermined function, or information indicating that the terminal device has introduced and tested a predetermined function. In the following description, whether or not a given function is supported includes whether or not the introduction and testing of the given function have been completed.

For example, when a terminal device supports a predetermined function, the terminal device transmits information (parameter) indicating whether or not the predetermined function is supported. When the terminal device does not support the predetermined function, the terminal device does not transmit information (parameter) indicating whether or not the predetermined function is supported. That is, whether or not the predetermined function is supported is notified by whether or not information (parameter) indicating whether or not the predetermined function is supported is transmitted. Information (parameter) indicating whether or not a predetermined function is supported may be notified using 1 bit of 1 or 0.

The radio resource control unit 1011 generates downlink data (transport block), system information, RRC message, MAC CE, or the like arranged on the downlink PDSCH, or acquires from the upper node. Radio resource control section 1011 outputs downlink data to transmission section 103 and outputs other information to control section 102. The wireless resource control unit 1011 also manages various setting information of the terminal device.

The scheduling unit 1012 determines frequencies and subframes to which physical channels (PDSCH and PUSCH) are assigned, coding rates and modulation schemes (or MCS) of physical channels (PDSCH and PUSCH), transmission power, and the like. The scheduling unit 1012 outputs the decided information to the control unit 102.

The scheduling unit 1012 generates information used for scheduling the physical channels (PDSCH and PUSCH) based on the scheduling result. The scheduling unit 1012 outputs the generated information to the control unit 102.

The control unit 102 generates a control signal for controlling the transmission unit 103 and the reception unit 104 based on the information input from the upper layer processing unit 101. The control unit 102 generates downlink control information based on the information input from the upper layer processing unit 101, and outputs the downlink control information to the transmission unit 103.

The transmission unit 103 generates a downlink reference signal according to the control signal input from the control unit 102, and encodes the HARQ indicator, the downlink control information, and the downlink data input from the higher layer processing unit 101. Then, the signal is modulated, the PHICH, PDCCH, EPDCCH, PDSCH, and the downlink reference signal are multiplexed, and the signal is transmitted to the terminal device 2A via the transmission/reception antenna 105.

The coding unit 1031 performs block coding, convolutional coding, turbo coding, LDPC (Low Density Parity Check: Low density) on the HARQ indicator, the downlink control information, and the downlink data input from the higher layer processing unit 101. encoding is performed using a predetermined encoding method such as parity check) encoding or Polar encoding, or encoding is performed using an encoding method determined by the radio resource control unit 1011. The modulation unit 1032 determines the coded bits input from the coding unit 1031 in advance with BPSK (Binary Phase Shift Keying), QPSK (quadrature Phase Shift Keying), 16QAM (quadrature amplitude modulation), 64QAM, 256QAM, etc. Alternatively, it is modulated by the modulation method determined by the radio resource control unit 1011.

The downlink reference signal generation unit 1033 refers to a sequence known to the terminal device 2A, which is obtained by a predetermined rule based on a physical cell identifier (PCI, cell ID) for identifying the base station device 1A. Generate as a signal.

The multiplexing unit 1034 multiplexes the modulated modulation symbol of each channel, the generated downlink reference signal, and the downlink control information. That is, multiplexing section 1034 arranges the modulated symbols of each modulated channel, the generated downlink reference signal, and downlink control information in resource elements.

The wireless transmission unit 1035 generates an OFDM symbol by performing an Inverse Fast Fourier Transform (IFFT) on the multiplexed modulation symbols and the like, and adds a cyclic prefix (cyclic prefix: CP) to the OFDM symbol to base it. A band digital signal is generated, a baseband digital signal is converted into an analog signal, unnecessary frequency components are removed by filtering, up-converted to a carrier frequency, power is amplified, and output to a transmitting/receiving antenna 105 for transmission. ..

The reception unit 104 separates, demodulates, and decodes the reception signal received from the terminal device 2A via the transmission/reception antenna 105 according to the control signal input from the control unit 102, and outputs the decoded information to the upper layer processing unit 101. ..

The wireless reception unit 1041 down-converts an uplink signal received via the transmission/reception antenna 105 into a baseband signal, removes unnecessary frequency components, and amplifies so that the signal level is appropriately maintained. The 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 wireless reception unit 1041 removes the portion corresponding to the CP from the converted digital signal. The wireless reception unit 1041 performs a fast Fourier transform (FFT) on the signal from which the CP is removed, extracts a frequency domain signal, and outputs the signal to the demultiplexing unit 1042.

The demultiplexing unit 1042 separates the signal input from the wireless reception unit 1041 into signals such as PUCCH, PUSCH, and uplink reference signal. Note that this separation is performed based on the radio resource allocation information included in the uplink grant that the base station device 1A has previously determined by the radio resource control unit 1011 and has notified each terminal device 2A.

Also, the demultiplexing unit 1042 compensates the propagation paths of PUCCH and PUSCH. Also, the demultiplexing unit 1042 separates the uplink reference signal.

The demodulation unit 1043 performs inverse discrete Fourier transform (Inverse Discrete Fourier Transform: IDFT) on the PUSCH, obtains a modulation symbol, and for each of the PUCCH and PUSCH modulation symbols, BPSK, QPSK, 16QAM, 64QAM, 256QAM, and the like in advance. The received signal is demodulated by using the modulation method which is set or which the terminal apparatus has previously notified to the terminal apparatus 2A by the uplink grant.

The decoding unit 1044 uses the coded bits of the demodulated PUCCH and PUSCH at a coding rate of a predetermined coding method, a predetermined coding rate, or a coding rate that the apparatus itself notifies the terminal apparatus 2A in advance by an uplink grant. Decoding is performed, and the decoded uplink data and uplink control information are output to upper layer processing section 101. When PUSCH is retransmitted, decoding section 1044 performs decoding using the coded bits held in the HARQ buffer input from upper layer processing section 101 and the demodulated coded bits.

The measuring unit 106 observes the received signal and obtains various measured values such as RSRP/RSRQ/RSSI. The measurement unit 106 also obtains received power, reception quality, and a suitable SRS resource index from the SRS transmitted from the terminal device.

FIG. 3 is a schematic block diagram showing the configuration of the terminal device according to the present embodiment. As shown in FIG. 3, the terminal device includes an upper layer processing unit (upper layer processing step) 201, a control unit (control step) 202, a transmission unit (transmission step) 203, a reception unit (reception step) 204, and a measurement unit ( A measurement step) 205 and a transmission/reception antenna 206 are included. The upper layer processing unit 201 is configured to include a radio resource control unit (radio resource control step) 2011 and a scheduling information interpretation unit (scheduling information interpretation step) 2012. Further, the transmission unit 203 includes a coding unit (coding step) 2031, a modulation unit (modulation step) 2032, an uplink reference signal generation unit (uplink reference signal generation step) 2033, a multiplexing unit (multiplexing step) 2034, and a radio. A transmitter (wireless transmission step) 2035 is included. The receiving unit 204 includes a wireless receiving unit (wireless receiving step) 2041, a demultiplexing unit (demultiplexing step) 2042, and a signal detecting unit (signal detecting step) 2043.

The upper layer processing unit 201 outputs the uplink data (transport block) generated by a user operation or the like to the transmitting unit 203. In addition, the upper layer processing unit 201 is a medium access control (Medium Access Control: MAC) layer, a packet data integration protocol (Packet Data Convergence Protocol: PDCP) layer, a radio link control (Radio Link Control: RLC) layer, a radio resource control. (Radio Resource Control:RRC) Layer processing is performed.

The upper layer processing unit 201 outputs information indicating the function of the terminal device supported by the own terminal device to the transmitting unit 203.

The wireless resource control unit 2011 manages various setting information of its own terminal device. In addition, the radio resource control unit 2011 generates information arranged in each uplink channel and outputs the information to the transmission unit 203.

The wireless resource control unit 2011 acquires the setting information transmitted from the base station device and outputs it to the control unit 202.

The scheduling information interpretation unit 2012 interprets the downlink control information received via the reception unit 204 and determines the scheduling information. The scheduling information interpretation unit 2012 also generates control information for controlling the reception unit 204 and the transmission unit 203 based on the scheduling information, and outputs the control information to the control unit 202.

The control unit 202 generates a control signal for controlling the receiving unit 204, the measuring unit 205, and the transmitting unit 203 based on the information input from the upper layer processing unit 201. The control unit 202 outputs the generated control signal to the receiving unit 204, the measuring unit 205, and the transmitting unit 203 to control the receiving unit 204 and the transmitting unit 203.

The control unit 202 controls the transmission unit 203 to transmit the CSI/RSRP/RSRQ/RSSI generated by the measurement unit 205 to the base station device.

The reception unit 204 separates, demodulates, and decodes the reception signal received from the base station device via the transmission/reception antenna 206 according to the control signal input from the control unit 202, and outputs the decoded information to the upper layer processing unit 201. To do.

The wireless reception unit 2041 down-converts the downlink signal received via the transmission/reception antenna 206 into a baseband signal, removes unnecessary frequency components, and an amplification level so that the signal level is appropriately maintained. Quadrature demodulation 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.

Also, the wireless reception unit 2041 removes a portion corresponding to the CP from the converted digital signal, performs a fast Fourier transform on the signal from which the CP is removed, and extracts a signal in the frequency domain.

Demultiplexing section 2042 separates the extracted signal into PHICH, PDCCH, EPDCCH, PDSCH, and downlink reference signal. Further, demultiplexing section 2042 performs channel compensation for PHICH, PDCCH, and EPDCCH based on the channel estimation value of the desired signal obtained from the channel measurement, detects downlink control information, and causes control section 202 to control. Output. Further, the control unit 202 outputs the PDSCH and the channel estimation value of the desired signal to the signal detection unit 2043.

The signal detection unit 2043 demodulates and decodes using the PDSCH and the channel estimation value, and outputs it to the upper layer processing unit 201. Further, when removing or suppressing the interference signal, the signal detection unit 2043 obtains the channel estimation value of the interference channel using the parameter of the interference signal, and demodulates and decodes the PDSCH.

The measurement unit 205 performs various measurements such as CSI measurement, RRM (Radio Resource Management) measurement, and RLM (Radio Link Monitoring) measurement, and obtains CSI/RSRP/RSRQ/RSSI.

The transmission unit 203 generates an uplink reference signal according to the control signal input from the control unit 202, encodes and modulates the uplink data (transport block) input from the higher layer processing unit 201, and PUCCH, The PUSCH and the generated uplink reference signal are multiplexed and transmitted to the base station apparatus via the transmission/reception antenna 206.

The coding unit 2031 performs coding such as convolutional coding, block coding, turbo coding, LDPC coding, and Polar coding on the uplink control information or uplink data input from the upper layer processing unit 201.

The modulation unit 2032 modulates the coded bits input from the coding unit 2031 by the modulation method notified by the downlink control information such as BPSK, QPSK, 16QAM, 64QAM, or a predetermined modulation method for each channel. ..

The uplink reference signal generation unit 2033 uses a physical cell identifier (referred to as physical cell identity: PCI, Cell ID, etc.) for identifying the base station device, a bandwidth in which the uplink reference signal is arranged, and an uplink grant. A sequence determined by a predetermined rule (expression) is generated based on the notified cyclic shift, the value of the parameter for generating the DMRS sequence, and the like.

The multiplexing unit 2034 multiplexes the PUCCH and PUSCH signals and the generated uplink reference signal for each transmission antenna port. That is, multiplexing section 2034 arranges the PUCCH and PUSCH signals and the generated uplink reference signal in resource elements for each transmission antenna port.

The wireless transmission unit 2035 performs an inverse fast Fourier transform (Inverse Fast Fourier Transform: IFFT) on the multiplexed signal, performs OFDM modulation, generates an OFDMA symbol, and adds a CP to the generated OFDMA symbol, Generates a baseband digital signal, converts the baseband digital signal to an analog signal, removes excess frequency components, converts to a carrier frequency by up-conversion, power-amplifies, outputs to the transmitting/receiving antenna 206, and transmits. To do.

Note that the terminal device can perform not only the OFDMA method but also the SC-FDMA method.

When ultra-high-capacity communication such as ultra-high-definition video transmission is required, ultra-wide band transmission utilizing high frequency band is desired. For transmission in the high frequency band, it is necessary to compensate for path loss, and beamforming is important. In an environment where multiple terminal devices exist in a certain limited area, when ultra-high capacity communication is required for each terminal device, an ultra-dense network (Ultra-dense network) in which base station devices are densely arranged network) is valid. However, when the base station devices are arranged at a high density, although the SNR (Signal to noise power ratio) is greatly improved, strong interference may occur due to beamforming. Therefore, in order to realize super-high-capacity communication for all terminal devices in a limited area, interference control (avoidance, suppression, removal) considering beamforming and/or cooperative communication of a plurality of base stations is required. Will be required.

FIG. 4 shows an example of a downlink communication system according to this embodiment. The communication system shown in FIG. 4 includes a base station device 3A, a base station device 5A, and a terminal device 4A. The terminal device 4A can use the base station device 3A and/or the base station device 5A as a serving cell. When the base station device 3A or the base station device 5A is provided with a large number of antennas, the large number of antennas is divided into a plurality of subarrays (panels, subpanels, transmission antenna ports, transmission antenna groups, reception antenna ports, reception antenna groups). It is possible to apply transmit/receive beamforming to each sub-array. In this case, each sub-array can include a communication device, and the configuration of the communication device is the same as that of the base station device shown in FIG. 2 unless otherwise specified. When the terminal device 4A includes a plurality of antennas, the terminal device 4A can perform transmission or reception by beamforming. In addition, when the terminal device 4A is provided with a large number of antennas, the large number of antennas can be divided into a plurality of subarrays (panel, subpanel, transmission antenna port, transmission antenna group, reception antenna port, reception antenna group). Different transmit/receive beamforming can be applied to each. Each sub-array can include a communication device, and the configuration of the communication device is the same as the configuration of the terminal device shown in FIG. 3 unless otherwise specified. The base station device 3A and the base station device 5A are also simply referred to as base station devices. The terminal device 4A is also simply referred to as a terminal device.

A synchronization signal is used to determine a suitable transmission beam for the base station device and a suitable reception beam for the terminal device. The base station device transmits a synchronization signal block composed of PSS, PBCH, and SSS. It should be noted that within the synchronization signal block burst set period set by the base station apparatus, one or more synchronization signal blocks are transmitted in the time domain, and a time index is set for each synchronization signal block. The terminal device determines that the sync signal block having the same time index within the sync signal block burst set period is a delay spread, a Doppler spread, a Doppler shift, an average gain, an average delay, a spatial reception parameter, and/or a spatial transmission parameter. Can be regarded as being transmitted from the same position (quasi co-located: QCL) that is considered to be the same. The spatial reception parameters (Rx parameters, reception filters) are, for example, spatial correlation of channels, angle of arrival (angle of arrival), reception beam direction, and the like. The spatial transmission parameters are, for example, channel spatial correlation, transmission angle (Angle Departure), transmission beam direction, and the like. That is, the terminal device can assume that within the synchronization signal block burst set period, synchronization signal blocks with the same time index are transmitted with the same transmission beam, and synchronization signal blocks with different time indexes are transmitted with different beams. Therefore, if the terminal device reports to the base station device information indicating the time index of a suitable synchronization signal block within the synchronization signal block burst set period, the base station device can know the transmission beam suitable for the terminal device. Further, the terminal device can obtain a reception beam suitable for the terminal device by using the synchronization signal blocks having the same time index in different synchronization signal block burst set periods. Therefore, the terminal device can associate the time index of the synchronization signal block with the reception beam direction and/or the sub-array. When the terminal device includes a plurality of sub-arrays, different sub-arrays may be used when connecting to different cells. The time index of the synchronization signal block is also referred to as SSB index or SSB resource indicator (SSBRI).

Also, there are four QCL types that indicate the QCL status. The four QCL types are called QCL type A, QCL type B, QCL type C, and QCL type D, respectively. QCL type A is a relationship (state) in which Doppler shift, Doppler spread, average delay, and delay spread become QCL. QCL type B is a relationship (state) in which Doppler shift and Doppler spread are QCL. The QCL type C is a relationship (state) in which the average delay and the Doppler shift are QCL. The QCL type D is a relationship (state) in which the spatial reception parameter is QCL. The above four QCL types can be combined with each other. For example, QCL type A+QCL type D, QCL type B+QCL type D, and the like.

Also, one or more TCI (Transmit Configuration Indicator) states are set by the signal of the upper layer. One TCI state can set the QCL type with one or a plurality of downlink signals in a certain cell (cell ID) and a certain partial band (BWP-ID). The downlink signal includes CSI-RS and SSB. The TCI state is included in DCI, for example, and can be used for demodulation (decoding) of the associated PDSCH. When QCL type D is set in the TCI state received by DCI, the terminal device can know the reception beam direction of the associated PDSCH. Therefore, the TCI can be said to be information related to the reception beam direction of the terminal device.

Also, CSI-RS can be used to determine a suitable transmission beam of the base station device and a suitable reception beam of the terminal device.

The terminal device receives the CSI-RS with the resource set in the CSI resource setting, calculates the CSI or RSRP from the CSI-RS, and reports it to the base station device. In addition, when the CSI-RS resource setting includes a plurality of CSI-RS resource settings and/or when resource repetition is OFF, the terminal device receives the CSI-RS with the same reception beam on each CSI-RS resource, Calculate the CRI. For example, when the CSI-RS resource set configuration includes K (K is an integer of 2 or more) CSI-RS resource configurations, the CRI indicates N preferred CSI-RS resources from the K CSI-RS resources. .. However, N is a positive integer less than K. Further, when the terminal device reports a plurality of CRIs, the terminal device may report the CSI-RSRP measured by each CSI-RS resource to the base station device in order to indicate which CSI-RS resource has good quality. it can. If the base station apparatus performs beamforming (precoding) of CSI-RSs in different beam directions with a plurality of set CSI-RS resources and transmits the CSI-RSs, the base station apparatus suitable for the terminal apparatus according to the CRI reported from the terminal apparatus. It is possible to know the transmission beam direction of. On the other hand, the preferred reception beam direction of the terminal device can be determined by using the CSI-RS resource in which the transmission beam of the base station device is fixed. For example, when the CSI-RS resource setting includes a plurality of CSI-RS resource settings and/or when resource repetition is ON, the terminal apparatus receives CSI-RS resources received in different reception beam directions in each CSI-RS resource. A suitable reception beam direction can be obtained from RS. The terminal device may report CSI-RSRP after determining a suitable reception beam direction. When the terminal device includes a plurality of sub-arrays, the terminal device can select a suitable sub-array when obtaining a suitable reception beam direction. Note that the preferred receive beam direction of the terminal device may be associated with the CRI. Further, when the terminal device reports a plurality of CRIs, the base station device can fix the transmission beam with the CSI-RS resource associated with each CRI. At this time, the terminal device can determine a suitable reception beam direction for each CRI. For example, the base station apparatus can associate the downlink signal/channel with the CRI and transmit. At this time, the terminal device must receive with the receive beam associated with the CRI. Also, different CSI-RSs can be transmitted by different base station apparatuses in the set plurality of CSI-RS resources. In this case, the CRI allows the network side to know from which base station device the communication quality is good. Also, when the terminal device includes a plurality of sub-arrays, the sub-arrays can be received at the same timing. Therefore, if the base station device transmits the CRI by associating each of the plurality of layers (codewords, transport blocks) with downlink control information and the like, the terminal device uses the sub-array and the reception beam corresponding to each CRI, Multiple layers can be received. However, in the case of using an analog beam, when one reception beam direction is used in one sub array at the same timing, and when two CRIs corresponding to one sub array of the terminal device are simultaneously set, the terminal device is It may not be possible to receive with multiple receive beams. In order to avoid this problem, for example, the base station device divides a plurality of set CSI-RS resources into groups, and within the group, the CRI is obtained using the same subarray. If different subarrays are used between groups, the base station device can know a plurality of CRIs that can be set at the same timing. The group of CSI-RS resources may be CSI-RS resources set by CSI resource setting or CSI-RS resource set setting. The CRI that can be set at the same timing may be QCL. At this time, the terminal device can transmit the CRI in association with the QCL information. The QCL information is information on the QCL for a given antenna port, a given signal, or a given channel. At two antenna ports, if the long-term characteristics of the channel carrying the symbols on one antenna port can be inferred from the channel carrying the symbols on the other antenna port, then those antenna ports are QCL. Is called. The long-term characteristic includes delay spread, Doppler spread, Doppler shift, average gain, average delay, spatial reception parameter, and/or spatial transmission parameter. For example, when two antenna ports are QCL, the terminal device can consider that the long-term characteristics in those antenna ports are the same. For example, if the terminal device separately reports a CRI that is QCL regarding spatial reception parameters and a CRI that is not QCL regarding spatial reception parameters, the base station device has the same CRI that is QCL regarding spatial reception parameters. It is possible to set the CRI that is not QCL with respect to the spatial reception parameter to the same timing without setting the timing. Moreover, the base station apparatus may request CSI for each sub-array of the terminal apparatus. In this case, the terminal device reports the CSI for each sub array. When the terminal device reports a plurality of CRIs to the base station device, it may report only the CRIs that are not QCL.

Also, in order to determine a suitable transmission beam of the base station device, a codebook in which predetermined precoding (beamforming) matrix (vector) candidates are defined is used. The base station apparatus transmits CSI-RS, the terminal apparatus obtains a suitable precoding (beamforming) matrix from the codebook, and reports it to the base station apparatus as PMI. By this means, the base station apparatus can know the transmission beam direction suitable for the terminal apparatus. The codebook includes a precoding (beamforming) matrix for synthesizing antenna ports and a precoding (beamforming) matrix for selecting antenna ports. When a codebook that selects antenna ports is used, the base station apparatus can use different transmission beam directions for each antenna port. Therefore, if the terminal device reports an antenna port suitable for PMI, the base station device can know a suitable transmission beam direction. The preferred receive beam of the terminal device may be the receive beam direction associated with the CRI, or the preferred receive beam direction may be determined again. When a codebook for selecting an antenna port is used and a preferred receive beam direction of a terminal device is a receive beam direction associated with CRI, a receive beam direction for receiving CSI-RS is a receive beam direction associated with CRI. It is desirable to receive in the direction. Note that the terminal device can associate the PMI with the receive beam direction even when using the receive beam direction associated with the CRI. Moreover, when using the codebook which selects an antenna port, each antenna port may be transmitted from a different base station apparatus (cell). In this case, if the terminal device reports the PMI, the base station device can know with which base station device (cell) the communication quality is suitable. In this case, the antenna ports of different base station devices (cells) may not be QCL.

-Cooperative communication between multiple base station devices (transmission/reception points) is possible to improve reliability and frequency utilization efficiency. Collaborative communication between a plurality of base station devices (transmission/reception points) includes, for example, DPS (Dynamic Point Selection) that dynamically switches a suitable base station device (transmission/reception point), a plurality of base station devices (transmission/reception points). There is a JT (Joint Transmission) that transmits a data signal from the device. When communicating with a plurality of base station devices, the terminal device may communicate using a plurality of subarrays. For example, the terminal device 4A can use the sub array 1 when communicating with the base station device 3A, and can use the sub array 2 when communicating with the base station device 5A. Further, when the terminal device performs cooperative communication with the plurality of base station devices, there is a possibility that the plurality of subarrays may be dynamically switched, or the plurality of subarrays may transmit/receive at the same timing. At this time, it is desirable that the terminal device 4A and the base station device 3A/5A share information regarding the sub-array of the terminal device used for communication.

The terminal device can include CSI setting information in the CSI report. For example, the CSI setting information can include information indicating a sub array. For example, the terminal device can transmit a CSI report including a CRI and an index indicating a subarray. By this means, the base station apparatus can associate the transmission beam direction with the subarray of the terminal apparatus. Alternatively, the terminal device can send a CRI report including a plurality of CRIs. In this case, if it is specified that some of the plurality of CRIs are associated with sub-array 1 and the remaining CRIs are associated with sub-array 2, the base station apparatus can associate the CRI with the index indicating the sub-array. Also, the terminal apparatus can jointly code the CRI and the index indicating the subarray to transmit the CRI report in order to reduce the control information. In this case, of N (N is an integer of 2 or more) bits indicating CRI, one bit indicates sub-array 1 or sub-array 2, and the remaining bits indicate CRI. In the case of joint coding, 1 bit is used for the index indicating the sub array, so the number of bits that can express the CRI decreases. Therefore, when reporting CSI including an index indicating a sub-array, the terminal device may detect CRI from some CSI-RS resources if the number of CSI-RS resources indicated by the CSI resource setting is larger than the number capable of expressing CRI. Can be asked. In addition, when it is decided to calculate CSI in different sub-arrays in different CSI resource settings, if the terminal device transmits the CSI calculated in different sub-arrays for each resource setting ID, the base station device will be set for each sub-array of the terminal. Can know the CSI.

The CSI setting information can also include CSI measurement setting information. For example, the setting information for CSI measurement may be measurement link setting or other setting information. This allows the terminal device to associate the CSI measurement setting information with the sub-array and/or receive beam direction. For example, considering cooperative communication with two base station devices (for example, the

base station devices

3A and 5A), it is desirable that there be some setting information. The CSI-RS setting for channel measurement transmitted by the base station device 3A is referred to as resource setting 1, and the CSI-RS setting for channel measurement transmitted by the base station device 5A is referred to as resource setting 2. In this case, the setting information 1 can be the resource setting 1, the setting information 2 can be the resource setting 2, and the setting information 3 can be the resource setting 1 and the resource setting 2. Note that each setting information may include the setting of the interference measurement resource. If the CSI measurement is performed based on the setting information 1, the terminal device can measure the CSI with the CSI-RS transmitted from the base station device 3A. If the CSI measurement is performed based on the setting information 2, the terminal device can measure the CSI transmitted from the base station device 5A. If the CSI measurement is performed based on the setting information 3, the terminal device can measure the CSI with the CSI-RS transmitted from the base station device 3A and the base station device 5A. The terminal device can associate each of the setting information 1 to 3 with the sub-array and/or the reception beam direction used for the CSI measurement. Therefore, the base station apparatus can instruct the preferred sub-array and/or the reception beam direction used by the terminal apparatus by instructing the setting information 1 to 3. When the setting information 3 is set, the terminal device obtains the CSI for the resource setting 1 and/or the CSI for the resource setting 2. At this time, the terminal device can associate the sub-array and/or the reception beam direction with each of the resource setting 1 and/or the resource setting 2. It is also possible to associate resource setting 1 and/or resource setting 2 with a codeword (transport block). For example, the CSI for resource setting 1 can be the CSI for codeword 1 (transport block 1) and the CSI for resource setting 2 can be the CSI for codeword 2 (transport block 2). Further, the terminal device can also obtain one CSI in consideration of the resource setting 1 and the resource setting 2. However, the terminal device can associate the sub-array and/or the reception beam direction with respect to each of resource setting 1 and resource setting 2 even when obtaining one CSI.

In addition, the CSI setting information includes, when a plurality of resource settings are set (for example, when the above setting information 3 is set), the CSI includes one CRI or a CRI for each of the plurality of resource settings. Information indicating whether to include may be included. When the CSI includes one CRI, the CSI setting information may include a resource setting ID for which the CRI is calculated. The CSI setting information allows the base station apparatus to know under what assumption the terminal apparatus calculated the CSI or which resource setting the reception quality was good.

The base station device can send a CSI request requesting a CSI report to the terminal device. The CSI request may include reporting CSI in one subarray or reporting CSI in multiple subarrays. At this time, when requested to report the CSI in one subarray, the terminal device transmits a CSI report that does not include an index indicating the subarray. Also, when requested to report CSI in a plurality of subarrays, the terminal device transmits a CSI report including an index indicating the subarray. When requesting the CSI report in one sub array, the base station device can instruct the sub array that the terminal device calculates the CSI by using the index indicating the sub array or the resource setting ID. In this case, the terminal device calculates CSI with the subarray instructed by the base station device.

Also, the base station device can include the CSI measurement setting information in the CSI request for transmission. When the CSI request includes the CSI measurement setting information, the terminal device obtains the CSI based on the CSI measurement setting information. The terminal device reports the CSI to the base station device, but does not have to report the CSI measurement setting information.

The terminal device and the base station device according to the present embodiment can newly set a virtual antenna port in order to select a suitable subarray. The virtual antenna ports are each associated with a physical subarray and/or receive beam. The base station device can notify the terminal device of the virtual antenna port, and the terminal device can select a subarray for receiving the PDSCH. Further, QCL can be set for the virtual antenna port. The base station device can notify the plurality of terminal devices of the virtual antenna port. When the notified virtual antenna port is QCL, the terminal device can receive the associated PDSCH by using one subarray, and the notified virtual antenna port is QCL. If not, two or more sub-arrays can be used to receive the associated PDSCH. The virtual antenna port can be associated with any one or a plurality of CSI-RS resources, DMRS resources, and SRS resources. By setting the virtual antenna port, the base station device provides a sub-array when the terminal device sends an RS in any one or more of CSI-RS resource, DMRS resource, and SRS resource. Can be set.

When a plurality of base station devices perform coordinated communication, it is desirable that the terminal device receives in a sub-array and/or receive beam direction suitable for the PDSCH transmitted by each base station device. Therefore, the base station apparatus transmits information that enables the terminal apparatus to receive in a suitable sub-array and/or receive beam direction. For example, the base station apparatus can include the CSI setting information or the information indicating the CSI setting information in the downlink control information for transmission. Upon receiving the CSI setting information, the terminal device can receive the CSI setting information in the sub-array and/or the receiving beam direction associated with the CSI setting information.

For example, the base station device can transmit information indicating a sub array and/or a reception beam direction as CSI setting information. The CSI setting information may be transmitted in a predetermined DCI format. Further, the information indicating the reception beam direction may be the CRI, PMI, and the time index of the synchronization signal block. The terminal device can know the suitable sub-array and/or the reception beam direction from the received DCI. The information indicating the sub array is represented by 1 bit or 2 bits. When the information indicating the sub array is indicated by 1 bit, the base station apparatus can indicate the sub array 1 or the sub array 2 to the terminal apparatus by "0" or "1". Moreover, when the information indicating the sub-array is indicated by 2 bits, the base station apparatus can switch the sub-array and instruct the terminal apparatus to receive the sub-array. When it is decided to calculate CSI in different subarrays with different resource settings, the base station apparatus can indicate the subarray of the terminal apparatus by transmitting the DCI including the resource setting ID.

For example, the base station device can transmit CSI measurement setting information as CSI setting information. In this case, the terminal device can receive the PDSCH in the sub-array and/or the reception beam direction associated with the CSI fed back in the setting information of the received CSI measurement. When the CSI measurement setting information indicates the setting information 1 or the setting information 2, the CSI setting information indicates that PDSCH transmission is associated with one resource setting information. When the CSI measurement setting information indicates the setting information 3, the CSI setting information indicates that PDSCH transmission is associated with a plurality of resource setting information.

Also, the CSI setting information may be associated with a parameter (field) included in the DCI such as a scrambling identity (SCID) of DMRS. For example, the base station device can set the association between the SCID and the setting information of the CSI measurement. In this case, the terminal device can refer to the CSI measurement setting information from the SCID included in the DCI, and receive the PDSCH in the sub-array and/or the receiving beam direction associated with the CSI measurement setting information.

Also, the base station device can set two DMRS antenna port groups. These two DMRS port groups are also referred to as DMRS port group 1 (first DMRS port group) and DMRS port group 2 (second DMRS port group). The antenna ports in the DMRS antenna port group are QCL, and the antenna ports between the DMRS antenna port groups are not QCL. Therefore, if the DMRS antenna port group and the subarray of the terminal device are associated with each other, the base station device can instruct the subarray of the terminal device by the DMRS antenna port number included in the DCI. For example, when the DMRS antenna port number included in DCI is included in one DMRS antenna port group, the terminal device receives in one subarray corresponding to the DMRS antenna port group. When the DMRS antenna port number included in the DCI is included in both of the two DMRS antenna port groups, the terminal device receives the terminal device with two subarrays. One DMRS antenna port group may be associated with one codeword (transport block). The relationship between the DMRS antenna port group and the codeword (transport block) index may be predetermined or may be instructed by the base station apparatus.

If it is decided to calculate CSI in different subarrays with different resource settings, if the DMRS antenna port group is associated with the resource setting ID or the CSI-RS resource, the DMRS antenna ports included in the DCI The terminal device can specify the resource setting ID or the CSI-RS resource, and can know the sub-array and/or the reception beam direction.

Also, the base station device can set the DMRS antenna port group and the CSI setting information in association with each other. When the CSI setting information includes the setting information for the CSI measurement and the setting information for the CSI measurement indicates the setting information 3, the terminal device corresponds to the resource setting 1 in the case of the DMRS antenna port included in the DMRS antenna port group 1. The demodulation is performed in the sub array and/or the reception beam direction, and when the DMRS antenna port included in the DMRS antenna port group 2 is demodulated in the sub array and/or the reception beam direction corresponding to the resource setting 2.

Also, in the CSI report setting, when the report amount is set to CRI/RSRP or SSBRI/RSRP, and the group-based beam reporting is set to OFF, the terminal device is different in one

report

1, 2 or Report 4 different CRIs or SSBRIs. In addition, when the report amount is set to CRI/RSRP or SSBRI/RSRP in the CSI report setting and the group-based beam reporting is set to ON, the terminal device uses two different CRIs or one in one report. Report SSBRI. However, two CSI-RS resources or two SSBs can be received simultaneously by one spatial domain reception filter or a plurality of spatial domain reception filters.

In addition, when the report amount is set to CRI, RI, and CQI in the CSI report setting and the group-based beam reporting is set to ON, the terminal device receives the reception filter (panel, sub array) in one spatial region. ) Or two CSI-RS resources that can be received simultaneously by a plurality of spatial domain reception filters (panels, subarrays). The two CSI-RS resources are called a first CSI-RS resource and a second CSI-RS resource, respectively. In addition, the CRI indicating the first CSI-RS resource is also referred to as a first CRI, and the CRI indicating the second CSI-RS resource is also referred to as a second CRI. In addition, the RI obtained by the first CSI-RS resource is also called a first RI, and the RI obtained by the second CSI-RS resource is also called a second RI. When RI is 4 or less (4 layers), the number of codewords is 1, and when RI is larger than 4, the number of codewords is 2. Therefore, the CSI reported by the terminal device may change depending on whether the sum of the first RI and the second RI is 4 or less or greater than 4. When the sum of the first RI and the second RI is 4 or less, the CQI obtained by considering both the first CSI-RS and the second CSI-RS is obtained. At this time, the terminal device obtains the CSI in consideration of the first CRI, the second CRI, the first RI, the second RI, and both the first CSI-RS and the second CSI-RS. Report the CQI. When the sum of the first RI and the second RI is larger than 4, the first CQI obtained by the first CSI-RS and the second CQI obtained by the second CSI-RS are obtained. At this time, the terminal device reports the first CRI, the second CRI, the first RI, the second RI, the first CQI, and the second CQI as the CSI.

In addition, when the report amount is set to CRI, RI, PMI, and CQI in the CSI report setting and the group-based beam reporting is set to ON, the terminal device may receive a reception filter or a plurality of reception filters in one spatial region. CSI is obtained based on two CSI-RS resources that can be simultaneously received by the spatial domain reception filter. Further, the PMI for the first CSI-RS resource is also referred to as a first PMI, and the PMI for the second CSI-RS resource is also referred to as a second PMI. Note that the first PMI and the second PMI may be obtained in consideration of both the first CRI and the second CRI. In this case, the first PMI and the second PMI considering mutual interference are obtained. Note that PMI is divided into PMI-1 and PMI-2 when CSI-RS has four or more antenna ports. PMI-1 is wideband information, and indicates a codebook index obtained based on at least N1 and N2. The number of antenna ports of CSI-RS is represented by 2N1N2. Note that N1 and N2 are both integers of 1 or more, N1 represents the number of antenna ports in the first dimension (eg, horizontal direction), and N2 represents the number of antenna ports in the second dimension (eg, vertical direction). The number of polarization antennas is two. Further, PMI-1 includes one or more pieces of information depending on the values of N1 and N2 and RI (number of layers). The PMI-2 is wideband or subband information and indicates at least phase rotation. The PMI-1 and PMI-2 obtained by the first CSI-RS resource are also referred to as the first PMI-1 and the first PMI-2, respectively. Further, PMI-1 and PMI-2 obtained by the second CSI-RS resource are also referred to as a second PMI-1 and a second PMI-2, respectively. The report amount may be set to CRI, RI, PMI-1, CQI. The CRI, RI, and CQI are the same as when the report amount is set to CRI, RI, and CQI. Therefore, when the total of the first RI and the second RI is 4 or less, the terminal device determines that the CSI is the first CRI, the second CRI, the first RI, the second RI, the first PMI. The CQI obtained by considering (PMI-1), the second PMI (PMI-1), and both the first CSI-RS and the second CSI-RS is reported. When the sum of the first RI and the second RI is greater than 4, the terminal device determines that the CSI is the first CRI, the second CRI, the first RI, the second RI, and the first PMI. (PMI-1), second PMI (PMI-1), first CQI, and second CQI are reported.

If the sum of the first RI and the second RI is greater than 4, the number of layers with a codeword number of 1 is equal to or smaller than the number of layers with a codeword number of 2, so the first RI is the same as the second RI. Same or smaller. That is, when the RI is reported, it is preferable that the first CRI and the second CRI have better reception power (RSRP)/reception quality (RSRQ) than the first CRI, and the first CRI or The second CRI is determined. When the number of layers of codeword 1 and the number of layers of codeword 2 are different, the difference is 1. That is, when the sum of the first RI and the second RI is 5, the first RI is 2 and the second RI is 3. Further, when the total of the first RI and the second RI is 6, the first RI is 3 and the second RI is 3. If the sum of the first RI and the second RI is 7, the first RI is 3 and the second RI is 4. If the sum of the first RI and the second RI is 8, the first RI is 4 and the second RI is 4. When the difference between the first RI and the second RI is greater than 1, the terminal device may report the CSI of either the first CRI or the second CRI, for example, the one with the larger RI value. .. In addition, because of the above rule, the terminal device may report the total value of the first RI and the second RI without separately reporting the first RI and the second RI. When the group-based beam reporting is set to ON and the report amount is set to CRI, RI, CQI or CRI, RI, PMI (PMI-1), and CQI, the first CRI and the second CRI are set. Different CRIs may result in different codewords. At this time, as the CQI, the first CQI and the second CQI are reported. However, the total of the first RI and the second RI is 8 or less, and the RI in one CRI is 4 or less. When different codewords are used for the first CRI and the second CRI, the base station apparatus may instruct the terminal apparatus. Even if the first CRI and the second CRI have different codewords, the difference may be 1 when the number of layers of codeword 1 and the number of layers of codeword 2 are different. At this time, when the total of the first RI and the second RI is 4, the first RI is 2 and the second RI is 2. If the sum of the first RI and the second RI is 3, the first RI is 1 and the second RI is 2. When the sum of the first RI and the second RI is 2, the first RI is 1 and the second RI is 1.

Also, for the priority of CSI reporting, the CRI with the larger RI is set higher. That is, in the present embodiment, the second CRI has a higher priority than the second CRI. For example, when the information amount of PUCCH is insufficient, the RI/PMI/CQI obtained by the second CRI and the second CRI is reported, and the RI/PMI/CQI obtained by the first CRI and the first CRI are To drop. When the CQI is reported by one of the CRIs, the CQI obtained by the one CRI is reported even if the total of the first RI and the second RI is 4 or less.

When CSI is reported on PUSCH or subband CSI is reported on PUCCH, CSI is divided into two parts and reported. The two parts are also referred to as a first part (part 1, CSI part 1) and a second part (part 2, CSI part 2). The first part has a higher priority in CSI reporting than the second part. For example, when RI is 4 or less, the first part is the sum of the first RI and the second RI (or the second RI), the second CRI, the CQI based on the first CRI and the second CRI. (Or the second CQI) is partially or entirely included. The second part includes a part or all of the first CRI, the first RI, the first CQI, the first PMI, and the second PMI. If the RI is greater than 4, the first part includes the sum of the first RI and the second RI (or the second RI), the second CRI, or some or all of the second CQI. The second part includes a part or all of the first CRI, the first RI, the first CQI, the first PMI, and the second PMI. The CSI may be divided into three. The third part is also called the third part (part 3, CSI part 3). The third part has lower priority than the second part. At this time, the first part is the sum of the first RI and the second RI (or the second RI), the second CRI, the CQI based on the first CRI and the second CRI (or the second CQI). ) Is included in part or all. The second part includes part or all of the first CRI, the first RI, and the first CQI. The third part includes a part or all of the first PMI and the second PMI.

Note that the terminal device may report by dividing into two parts for each of the CSI based on the first CRI and the CSI based on the second CRI. The two parts of the CSI based on the first CRI are also called the first part 1 and the first part 2. Also, the two parts of the CSI based on the second CRI are also called the second part 1 and the second part 2. The first part 1 includes a part or all of the first CRI, the first RI, and the first CQI. Also, the first part 2 includes a first PMI. Further, the second part 1 includes a part or all of the second CRI, the second RI, and the second CQI. The second part 2 also includes a second PMI. The CSI priority can be set higher in the order of the second part 1, the first part 1, the second part 2, and the first part 2. At this time, the terminal device will report a long-period (small change) CSI in the second CRI and the first CRI, and the base station device and the terminal device will report the minimum CSI for the first CRI and the second CRI. It is possible to communicate using limited parameters. Further, the CSI priority can be set higher in the order of the second part 1, the second part 2, the first part 1, and the first part 2. At this time, the terminal device preferentially reports the complete CSI in the second CRI, so that the base station device and the terminal device can communicate using the detailed parameters regarding the second CRI.

When the first RI and the second RI are 4 or less and the first CRI and the second CRI are different codewords, the terminal device selects the CSI based on the first CRI and the second CRI. Report information indicating that either or both of the based CSIs are reported. Information indicating that either or both of the CSI based on the first CRI and the CSI based on the second CRI are reported is included in the first part of the CSI. The information indicating that the CSI based on the first CRI and/or the CSI based on the second CRI is reported indicates whether or not the first CRI is included in the second part of the CSI. May be.

Codebooks used for obtaining PMI include a type 1 codebook and a type 2 codebook. The PMI found by the type 1 codebook is also called a type 1 PMI, and the PMI found by the type 2 codebook is also called a type 2 PMI. When the type 1 codebook is set in the codebook setting, the type 1 PMI is reported, and when the type 2 codebook is set in the codebook setting, the type 2 PMI is reported. The CSI calculated based on the CSI is also referred to as a type 1 CSI, and the CSI calculated based on the type 2 codebook is also referred to as a type 2 CSI. For the type 1 codebook, candidate precoding matrices (vectors) are given in a table, and for the type 1 PMI, a suitable one is selected from the candidate precoding matrices (vectors). FIG. 5 is an example of a type 1 codebook in one layer, and FIG. 6 is an example of a type 1 codebook in two layers. Type ₁ PMIs include i _1,1 , i _1,2 , i ₂ , or i _1,3 . However, the type 1 codebook and the type 1 PMI are not limited to the examples of FIGS. 5 and 6. N ₁ is the number of antenna ports per polarization in the vertical direction (first dimension), O ₁ is the oversampling coefficient in the vertical direction (first dimension), and N ₂ is the horizontal direction (second dimension). The number of antenna ports per polarization, O ₂ indicates the horizontal direction (second dimension) oversampling coefficient. Further, k ₁ is 0 or an integer multiple of O ₁ , and k ₂ is an integer multiple of 0 or O ₂ . Further, i _1,3 represents k ₁ and k ₂ . Further, P _CSI-RS represents the number of antenna ports of _CSI-RS , and P _CSI-RS =2N ₁ N ₂ .

Also, the type 2 codebook is given by linear combination of orthogonal vectors. In the type 2 codebook, linear combination coefficients include a wideband amplitude coefficient, a subband amplitude coefficient, and a subband amplitude coefficient. The type 2 PMI includes a vector to be linearly combined, a wideband amplitude coefficient, a subband phase coefficient, and a subband amplitude coefficient. FIG. 7 shows amplitude coefficient candidates. FIG. 7A shows an example of wideband amplitude coefficient candidates, and FIG. 7B shows an example of subband amplitude coefficient candidates. Further, FIG. 8 shows an example of candidates for the subband phase coefficient. FIG. 8A shows an example of 3 bits, and FIG. 8B shows an example of 2 bits. The sub-band amplitude coefficient can be turned on/off (true/false) by the signal of the upper layer. The linear combination coefficient is an independent coefficient for the combined vector, polarization, layer, and subband. Generally, the type 2 PMI has higher accuracy than the type 1 PMI, but the amount of information is very large. Therefore, it is required to reduce the amount of information of type 2 PMI.

For example, it is assumed that the subband phase coefficient is N _p bits, the number of vectors to be combined is L, and the number of polarizations is 2. At this time, 2N _p L bits are required for one subband. For N subbands, 2N _p LN bits are needed. The number of subbands varies depending on the number of resource blocks of a bandwidth part (BWP), but is N=32 at maximum. Therefore, since the type 2 PMI has a large amount of information on the coefficients (phase, amplitude) of the subband, it is considered to reduce this. For example, it is conceivable to perform the discrete Fourier transform (DFT) or the discrete cosine transform (DCT) on the phase/amplitude coefficient obtained by the N subbands and compress the information amount into M components. Note that N is an integer of 4 or more, M is an integer of 1 or more, and M<N. If the terminal device feeds back M phase/amplitude coefficients, the amount of feedback information can be reduced. Note that M may be the same or different in the combined vector, polarization, and layer. Further, the value of M may be changed depending on the subband phase coefficient and the subband amplitude coefficient. For example, a combined vector having a large wideband amplitude is considered to have little change in the frequency domain because it is associated with a path having a short delay time. Therefore, the coefficient of the combined vector having a large wideband amplitude feeds back (reports) the M ₀ phase/amplitude coefficients, and the coefficient of the combined vector having a small wideband amplitude feeds back the M ₁ phase/amplitude coefficients. However, M ₀ and M ₁ are integers of 1 or more that satisfy M ₀ <M ₁ <N. Further, since the amplitude coefficient changes less in the frequency domain than the phase coefficient, M ₂ subband amplitude coefficients may be fed back and M ₃ subband phase coefficients may be fed back. However, M ₂ and M ₃ are integers of 1 or more that satisfy M ₂ <M ₃ <N. Further, M, M ₀ , M ₁ , M ₂ , or M ₃ may be a fixed value, may be set by the base station apparatus, or may be changed depending on the value of N. In addition, the terminal device compresses the information amount and performs CSI feedback when M, M ₀ , M ₁ , M ₂ , or M ₃ has a value smaller than N, and does not compress the information amount when N or more. CSI feedback may be provided. When the type 2 PMI is fed back without compression, it is calculated in subband units, but in compression, it may not be in subband units. For example, it may be a resource block unit or a plurality of resource block units different from the subband size. Therefore, in the present embodiment, what is described in subband units may be replaced with one or a plurality of resource block units, which are included in the present invention. When the type-2 codebook is set in the codebook setting and compression is instructed, the terminal device reports the compressed type-2 PMI.

By compressing the amount of information in the frequency domain, it is possible to reduce CSI feedback information for type 2 PMI. However, compressing the amount of information may deteriorate the accuracy of PMI, reduce CQI, and reduce throughput. Further, the degree of deterioration of CSI (PMI/CQI/RI) due to the information amount compression can be known by the terminal device by comparing the CSI before and after the compression, but the base station device cannot know. Therefore, it is desirable for the terminal device to report the degree of deterioration of CSI accuracy due to compression to the base station device. The degree of deterioration of CSI accuracy is also referred to as PAI (PMI Accuracy indicator; PMI accuracy index, PMI Accuracy information; PMI accuracy information). For example, PAI indicates by 1 bit whether or not CQI is lowered due to compression. In addition, PAI may indicate a CQI value that decreases due to compression. For example, PAI can indicate four types of 0, 1, 2, and “greater than 2”. When the PAI is 0, it indicates that the CQI value does not change due to compression. Further, when the PAI is 1 or 2, it indicates that the CQI is decreased by 1 or 2 by the compression. Also, when the PAI is “greater than 2”, it indicates that the CQI is reduced by 3 or more due to the compression. The PAI may indicate the statistic of the CQI reduction amount in all subbands (wide band) or the CQI reduction amount for each subband.

Also, the PAI may indicate whether or not the CQI is lower than that of the type 1 codebook due to compression. When the terminal device is required to report the CSI in the type 2 codebook when the CQI is lower than that in the type 1 codebook due to the compression, the terminal device can obtain the CSI obtained in the type 1 codebook You can report it. In this case, the maximum RI value may be the same as the maximum RI value (eg, 2 or 4) supported by the type 2 codebook. For example, when the maximum value of RI supported by the type 2 codebook is 2, the maximum value of RI is 2 when reporting the CSI calculated by the type 1 codebook instead of the type 2 codebook.

Also, the terminal device may decide the compression rate (the number of feedbacks). For example, the terminal device can set the compression ratio so that the CQI does not deteriorate due to the compression. In this case, the terminal device reports the amount of information after compression to the base station device. It is also possible to set M candidates to be fed back by the base station apparatus and feed back information indicating M reported by the terminal apparatus.

Also, if the CQI drops below a predetermined threshold due to compression, the terminal device may report the type 2 CSI without compression.

Also, the number of bits of the phase/amplitude coefficient before compression and the number of bits of the phase/amplitude coefficient after compression may be different. For example, the subband phase coefficient before compression may be obtained with 3 bits, and the subband phase coefficient after compression may be obtained with 2 bits. As a result, in addition to reducing the amount of information by compression, the effect of reducing the amount of information by roughing the quantization can be obtained.

If Type 2 CSI is reported in the CSI report, CSI Part 1 contains the number of non-zero wideband amplitude coefficients for each layer. Since the wideband amplitude coefficient considers L vectors in each of the two polarizations in one layer, there are 2L wideband amplitude coefficients. Since the largest amplitude among the 2L wideband amplitude coefficients is set to 1, the maximum number of reported wideband amplitude coefficients is 2L-1 per layer. The number of non-zero wideband amplitude coefficients represents the number of nonzero in 2L-1 amplitudes. CSI Part 2 is classified into CSI Part 2 wideband and CSI Part 2 subband. CSI Part 2 wideband includes wideband amplitude coefficients. The CSI Part 2 subband includes subband phase coefficients and/or subband amplitude coefficients.

If compressed type 2 CSI is reported in the CSI report, CSI part 1 contains the number of non-zero wideband amplitude coefficients for each layer. The number of non-zero wideband amplitude coefficients is related to the number of vectors to be linearly combined. CSI Part 2 wideband includes wideband amplitude coefficients. The CSI Part 2 subband includes the compressed subband phase coefficient and/or subband amplitude coefficient. When PAI is reported, it is included in CSI Part 2 wideband if PAI is wideband information, and included in CSI Part 2 subband if PAI is subband information. When the terminal device reports the value of M, CSI part 1 includes information indicating the value of M. By this means, the base station device can know the amount of information in CSI part 2. In addition, the PAI is included in the CSI part 1 when the PAI indicates whether to report the type 1 CSI. When the terminal device reports the PAI indicating that the CSI part 1 reports the type 1 CSI, the terminal device reports the type 1 CSI in the CSI part 2. Also, when PAI is reported in CSI Part 1, it can be a special case of the number of non-zero wideband amplitude coefficients and does not require new control information. The maximum number of non-zero wideband amplitude coefficients is 3, 5, and 7 when L=2, 3, and 4, respectively. Therefore, to represent the number of non-zero wideband amplitude coefficients with L=2, 3, 4 requires 2 bits, 3 bits, 3 bits respectively, but not all patterns. For example, if L=2, 00, 01, 10 represent the number of non-zero wideband amplitude coefficients, and 11 is not used for the number of non-zero wideband amplitude coefficients, then PAI reports Type 1 CSI. If 11 is reported, the base station apparatus can know that the type 1 PMI is reported in CSI part 2. Similarly, when reporting the number of non-zero wideband amplitude coefficients in 3 bits, if PAI indicates to report type 1 CSI, assuming 111 is not used in the number of non-zero wideband amplitude coefficients. , 111, the base station apparatus can know that type 1 CSI is reported in CSI part 2. Also, Type 1 CSI may be reported in CSI Part 2 when the number of non-zero wideband amplitude coefficients indicates 0.

Also, DMRS setting type 1 (first DMRS setting type) or DMRS setting type 2 (second DMRS setting type) is set as the DMRS for PDSCH or PUSCH. DMRS setting type 1 supports up to 8 DMRS antenna ports, and DMRS setting type 2 supports up to 12 DMRS antenna ports. The DMRS is code division multiplexed (CDM) with an orthogonal cover code (OCC). The OCC has a maximum code length of 4, which has a length of 2 in the frequency direction and a length of 2 in the time direction. The front-loaded DMRS is arranged in one symbol or two symbols. When the DMRS arranged in the front is one symbol, it cannot be multiplexed in the time direction, and therefore it is multiplexed only in the frequency direction. In this case, it may be called OCC=2. Up to 4 DMRS antenna ports are CDMed in OCC. The 4DMRS antenna ports for CDM are also called CDM group (DMRS CDM group). In this case, DMRS setting type 1 has two CDM groups, and DMRS setting type 2 has three CDM groups. DMRSs of different CDM groups are arranged in orthogonal resources. The two DMRS setting type 1 CDM groups are also referred to as CDM group 0 (first CDM group) and CDM group 1 (second CDM group). In addition, the three CDM groups of DMRS setting type 2 are also called CDM group 0 (first CDM group), CDM group 1 (second CDM group), and CDM group 2 (third CDM group). For DMRS configuration type 1, CDM group 0 includes DMRS antenna ports 1000, 1001, 1004, 1005 and CDM group 1 includes DMRS antenna ports 1002, 1003, 1006, 1007. For DMRS configuration type 2, CDM group 0 includes DMRS antenna ports 1000, 1001, 1006, 1007, CDM group 1 includes DMRS antenna ports 1002, 1003, 1008, 1009, and CDM group 2 includes DMRS antennas. Includes ports 1004, 1005, 1010, 1011. The CDM group related to DMRS is also referred to as DMRS CDM group.

The DMRS antenna port number for PDSCH or PUSCH and the number of DMRS CDM groups without data are indicated by DCI. The terminal device can know the number of DMRS antenna ports from the number of instructed DMRS antenna port numbers. In addition, the number of DMRS CDM groups without data indicates that PDSCH is not arranged in the resource in which DMRS of the related CDM group is arranged. When the number of DMRS CDM groups without data is 1, the referenced CDM group is CDM group 0, and when the number of DMRS CDM groups without data is 2, the referenced CDM groups are CDM group 0 and CDM group 1. If the number of DMRS CDM groups with and without data is 3, the referenced CDM groups are CDM group 0, CDM group 1 and CDM group 2.

Note that, for example, in the case of MU-MIMO (Multi-User-Multiple Input-Multiple Output) transmission, the DMRS for PDSCH or PUSCH may have different power from the PDSCH. For example, it is assumed that the base station apparatus spatially multiplexes the 4-layer PDSCH and transmits the PDSCH to each of the two terminal apparatuses. That is, the base station apparatus spatially multiplexes and transmits PDSCHs of 8 layers in total. In this case, the base station apparatus instructs the DMRS antenna port number of CDM group 0 to one terminal apparatus and the DMRS antenna port number of CDM group 1 to the other terminal apparatus. Further, the base station device instructs the two terminal devices that the number of DMRS CDM groups without data is 2. At this time, the spatial multiplexing number of DMRS is 4, whereas the spatial multiplexing number of PDSCH is 8, and the power ratio (offset) between DMRS and PDSCH is doubled (3 dB different). Further, for example, it is assumed that the base station apparatus spatially multiplexes the 4-layer PDSCH and transmits it to each of the three terminal apparatuses. That is, the base station apparatus spatially multiplexes 12 layers of PDSCHs for transmission. In this case, the base station device instructs the DMRS antenna port numbers of CDM group 0, CDM group 1 and CDM group 2 to the three terminal devices, respectively. Also, the base station device instructs the three terminal devices that the number of DMRS CDM groups without data is three. At this time, the spatial multiplexing number of DMRS is 4, whereas the spatial multiplexing number of PDSCH is 12, and the power ratio of DMRS and PDSCH is tripled (4.77 dB different). Therefore, the base station device or the terminal device transmits the DMRS and PDSCH in consideration of the power ratio of DMRS and PDSCH that is the number of CDM groups. Also, the base station apparatus or terminal apparatus demodulates (decodes) PDSCH in consideration of the power ratio of DMRS and PDSCH that is the number of CDM groups. In the case of SU-MIMO (Single user MIMO) transmission in which the number of spatially multiplexed signals is large, the power ratio between DMRS and PDSCH which is the number of CDM groups is also considered.

However, when the terminal device communicates with multiple base station devices (transmission/reception points), the power ratio of DMRS and PDSCH may be different from the above. For example, when a terminal device communicates with two base station devices (transmission/reception points), it is assumed that each base station device spatially multiplexes and transmits a 4-layer PDSCH. In this case, one base station device or two base station devices instructs the number of DMRS CDM groups without data to be 2. However, since the number of DMRS spatial multiplexing and the number of PDSCH spatial multiplexing transmitted from each base station device are both 4, the power ratio of DMRS and PDSCH is 1 (0 dB), and the power ratio of DMRS and PDSCH is You don't have to consider it. Therefore, the terminal device needs to know (determine) whether or not to demodulate (decode) PDSCH in consideration of the power ratio between DMRS and PDSCH. When the terminal device communicates with a plurality of base station devices (transmission/reception points), each base station device (transmission/reception point) may reduce the power of PDSCH according to the number of DMRS CDM groups without data, but In this case, reliability and throughput decrease.

The base station device can transmit information indicating whether to demodulate (decode) the PDSCH in consideration of the power ratio of DMRS and PDSCH or the power ratio of DMRS and PDSCH to the terminal device. In this case, the terminal device can demodulate (decode) the PDSCH according to information indicating whether to demodulate (decode) the PDSCH in consideration of the power ratio of the received DMRS and PDSCH or the power ratio of DMRS and PDSCH. it can.

Also, the terminal device can judge the power ratio of DMRS and PDSCH from the setting of the DMRS port group. For example, in DMRS setting type 1, DMRS port group 1 is set (associated) with CDM group 0, that is, DMRS ports 1000, 1001, 1004, 1005, and DMRS port group 2 is with CDM group 1, that is, DMRS ports 1002, 1003, It is assumed that 1006 and 1007 are set (associated). At this time, if the DMRS antenna port numbers set in the two DMRS port groups are indicated by the DCI, the terminal device can select the DMRS and PDSCH even if the number of DMRS CDM groups without data is 2 The PDSCH is demodulated (decoded) with a power ratio of 1 (0 dB). When the DMRS antenna port number set for only one DMRS port group is designated by DCI, the terminal device demodulates (decodes) PDSCH with the power ratio of DMRS and PDSCH set to 1 (0 dB).

Also, the terminal device can judge the power ratio between DMRS and PDSCH by TCI. When the received TCI is a setting for two DMRS port groups, the terminal device sets the power ratio of DMRS and PDSCH to 1 (0 dB) and PDSCH to DMSCH even if the number of DMRS CDM groups without data is 2 or 3. Demodulate (decode). In other cases, the terminal device determines the power ratio between DMRS and PDSCH according to the number of DMRS CDM groups with no data.

Also, the initial value of the DMRS sequence is calculated based on at least the NID and SCID. Two SCIDs are set at most, and are indicated by 0 or 1. The NID is associated with the SCID and is set in a higher layer signal. For example, the NID when SCID=0 and the NID when SCID=1 are set. If NID or SCID is not set, SCID=0 and NID becomes the physical cell ID. The SCID is included in DCI. Further, the SCID may indicate whether to demodulate (decode) PDSCH in consideration of the power ratio of DMRS and PDSCH. For example, when SCID=0, the terminal device demodulates (decodes) PDSCH in consideration of the power ratio of DMRS and PDSCH according to the number of DMRS CDM groups without data, and when SCID=1, the power ratio of DMRS and PDSCH. The PDSCH is demodulated (decoded) without considering Further, the SCID and the DMRS port group may be associated with each other. For example, the DMRS associated with DMRS port group 1 is sequenced with SCID=0, and the DMRS associated with DMRS port group 2 is sequenced with SCID=1.

When a terminal device communicates with a plurality of base station devices (transmission/reception points), when each base station device transmits a PDCCH to the terminal device in the same slot, each base station device determines different terminal devices. Spatial multiplexing can be performed by MU-MIMO. For example, consider a case where the base station device 3A transmits PDCCH1 (DCI1) to the terminal device 4A and the base station device 5A transmits PDCCH2 (DCI2) to the terminal device 4A. Note that PDCCH1 and PDCCH2 are transmitted in the same slot. Although not shown, it is assumed that the base station device 5A spatially multiplexes the terminal device 4A and the terminal device 4B. Further, assuming the DMRS setting type 2, the base station device 3A sets DMRS ports 1000, 1001, 1006, 1007 as the DMRS port group 1 in the terminal device 4A, and DMRS ports 1002, 1003 as the DMRS port group 2. It is assumed that 1008 and 1009 are set. The DMRS port numbers included in DCI1 are 1000, 1001, 1006, and 1007, and the number of CDM groups without data is 2. The DMRS port numbers included in DCI1 are 1002, 1003, 1008, and 1009, and the number of CDM groups without data is 3. At this time, the base station device 5A communicates with the terminal device 4B using DMRS port numbers 1004, 1005, 1010 and 1011. At this time, in the terminal device 4A, it can be seen that DCI1 indicates the DMRS of the DMRS port group 1, and DCI2 indicates the DMRS of the DMRS port group 2. Therefore, since the two DMRS CDM groups without data indicated by DCI1 are used for transmission to the own device, the power ratio between the DMRS DMRS ports 1000, 1001, 1006, 1007 indicated by DCI1 and the corresponding PDSCH. Can be determined to be 1 (0 dB). Further, among the three CDM groups without data indicated by DCI2, two CDM groups without data are used for transmission to the own device, and therefore DMRS ports 1002, 1003, 1008, 1009 indicated by DCI2 are used. It can be determined that the power ratio to the corresponding PDSCH is 2 (3 dB). In other words, when receiving two PDCCHs in the same slot, the terminal device considers the number of DMRS CDM groups with no data indicated by one DCI minus 1 and determines the power of DMRS and PDSCH. The ratio can be determined.

The terminal device may receive inter-user interference from the serving cell and interference signals from neighboring cells. The terminal device can improve reliability and throughput by removing or suppressing the interference signal. In order to remove or suppress the interference signal, the parameters of the interference signal are required. The interference signal is a PDSCH, PDCCH, or a reference signal addressed to an adjacent cell/other terminal device. E-MMSE (Enhanced-Minimum Mean Square Error), which estimates the channel of an interference signal and suppresses it with a linear weight, as a method of removing or suppressing the interference signal, an interference canceller that generates and removes a replica of the interference signal, and a desired signal And MLD (Maximum Likelihood Detection) that searches all transmission signal candidates of interference signals to detect desired signals, R-MLD (Reduced complexity-MLD) that reduces transmission signal candidates and has a lower calculation amount than MLD. Applicable. In order to apply these methods, it is necessary to perform channel estimation of the interference signal, demodulation of the interference signal, or decoding of the interference signal.

In order to remove or suppress the interference signal efficiently, the terminal device needs to know the parameter of the interference signal (adjacent cell). Therefore, the base station apparatus can transmit (set) the assist information including the parameter of the interference signal (adjacent cell) to the terminal apparatus in order to assist the terminal apparatus in removing or suppressing the interference signal. One or more sets of assist information are set. The assist information includes, for example, a physical cell ID, a virtual cell ID, a power ratio (power offset) of a reference signal and PDSCH, a scrambling identity of the reference signal, QCL information (quasi co-location information), CSI-RS resource setting, CSI. -RS antenna port number, subcarrier interval, resource allocation granularity, resource allocation information, Bandwidth Part Size setting, DMRS setting, DMRS antenna port number, number of layers, TDD DL/UL configuration, PMI, RI, modulation method, MCS (Modulation) and/or coding scheme), TCI status, and part or all of PT-RS information. The virtual cell ID is an ID virtually assigned to the cell, and there may be cells having the same physical cell ID but different virtual cell IDs. The QCL information is information on the QCL for a given antenna port, a given signal, or a given channel. The subcarrier spacing indicates a subcarrier spacing of an interference signal or a candidate of subcarrier spacing that may be used in the band. When the subcarrier interval included in the assist information and the subcarrier interval used for communication with the serving cell are different, the terminal device does not have to remove or suppress the interference signal. The candidate of the subcarrier interval that may be used in the band may indicate the normally used subcarrier interval. For example, the normally used subcarrier interval does not have to include a low frequency subcarrier interval that is used for highly reliable and low delay communication (emergency communication). The resource allocation granularity indicates the number of resource blocks whose precoding (beamforming) does not change. The DMRS setting indicates a part or all of information indicating PDSCH mapping type, additional arrangement of DMRS, power ratio of DMRS and PDSCH, DMRS setting type, number of DMRS symbols in forward arrangement, and OCC=2 or 4. DMRS resource allocation changes depending on the PDSCH mapping type. For example, in PDSCH mapping type A, DMRS is mapped to the third symbol of the slot. Also, for example, PDSCH mapping type B is mapped to the first OFDM symbol of the allocated PDSCH resource. The DMRS additional arrangement indicates whether or not there is an additional DMRS arrangement or an arrangement to be added. PT-RS information includes the presence (presence or absence) of PT-RS, the number of PT-RS ports, time density, frequency density, resource allocation information, related DMRS ports (DMRS port group), and power ratio between PT-RS and PDSCH. Including some or all of. It should be noted that some or all of the parameters included in the assist information are transmitted (set) by signals in the upper layer. Also, some or all of the parameters included in the assist information are transmitted as downlink control information. Moreover, when each parameter included in the assist information indicates a plurality of candidates, the terminal device blindly detects a suitable candidate from the candidates. Further, the terminal device blindly detects a parameter that is not included in the assist information.

When a terminal device communicates using multiple receive beam directions, the surrounding interference situation changes significantly depending on the receive beam directions. For example, an interference signal that is strong in one receive beam direction may be weak in another receive beam direction. The assist information of the cell, which is unlikely to be strong interference, is not only meaningless, but may be uselessly calculated when determining whether or not a strong interference signal is received. Therefore, it is desirable that the assist information be set for each receiving beam direction. However, since the base station device does not necessarily know the receiving direction of the terminal device, the information relating to the receiving beam direction may be associated with the assist information. For example, since the terminal device can associate the CRI and the receiving beam direction, the base station device can transmit (set) one or a plurality of assist information for each CRI. Further, since the terminal device can associate the time index of the synchronization signal block with the reception beam direction, the base station device can transmit (set) one or a plurality of assist information for each time index of the synchronization signal block. .. Further, since the terminal device can associate the PMI (antenna port number) with the reception beam direction, the base station device can transmit (set) one or a plurality of assist information for each PMI (antenna port number). .. Further, when the terminal device includes a plurality of sub-arrays, the reception beam direction is likely to change for each sub-array, and therefore the base station device transmits (sets) one or more assist information for each index associated with the sub-array of the terminal device. )can do. For example, since the terminal device can associate the TCI and the reception beam direction, the base station device can transmit (set) one or a plurality of assist information for each TCI. Further, when the terminal device communicates with a plurality of base station devices (transmission/reception points), the terminal device is likely to communicate with each base station device (transmission/reception point) in a different reception beam direction. Therefore, the base station device transmits (sets) one or more pieces of assist information for each piece of information indicating the base station device (transmission/reception point). The information indicating the base station device (transmission/reception point) may be a physical cell ID or a virtual cell ID. When different DMRS antenna port numbers are used in the base station device (transmission/reception point), the information indicating the DMRS antenna port number or the DMRS antenna group becomes the information indicating the base station device (transmission/reception point).

Note that the number of assist information set by the base station device for each CRI/TCI can be made common. Here, the number of assist information indicates the type of assist information, the number of elements of each assist information (for example, the number of cell ID candidates), and the like. In addition, the maximum number is set for the number of assist information set by the base station apparatus for each CRI/TCI, and the base station apparatus can set the assist information in each CRI/TCI within the range of the maximum value. ..

If the value of the scheduling offset indicating the scheduling start position of the terminal device is less than or equal to a predetermined value, the terminal device may encounter a situation in which the decoding of DCI is not in time for the reception of PDSCH. At this time, the terminal device can receive the PDSCH according to a preset default setting (for example, TCI default). However, even when performing interference suppression, if the scheduling offset is equal to or less than a predetermined value, the PDSCH Reception (setting of spatial domain reception filter) follows the default setting. However, regarding interference suppression, it is possible to follow the assist information notified by DCI even when the scheduling offset is equal to or less than a predetermined value. Further, the base station apparatus can set the terminal apparatus that receives PDSCH according to TCI default so as not to perform interference suppression on the PDSCH received according to TCI default. In other words, the terminal device can perform the reception process on the PDSCH received according to the TCI default without assuming the interference suppression.

Note that if the receiving beam direction of the terminal device changes, the transmitting antenna is likely not QCL. Therefore, the assist information can be associated with the QCL information. For example, when the base station device transmits (sets) the assist information of a plurality of cells, it is possible to instruct the terminal device which cell is the QCL (or which is not the QCL).

Note that the terminal device removes or suppresses the interference signal using the assist information associated with the CRI/TCI used for communication with the serving cell.

In addition, the base station apparatus uses the assist information associated with the reception beam direction (CRI/synchronization signal block time index/PMI/antenna port number/subarray/TCI) and the reception beam direction (CRI/sync signal block time index/ Assist information that is not associated with PMI/antenna port number/subarray/TCI) may be set. Further, the assist information associated with the receiving beam direction and the assist information not associated with the receiving beam direction may be selectively used depending on the capability or category of the terminal device. The capability or category of the terminal device may indicate whether or not the terminal device supports receive beamforming. Further, the assist information associated with the receive beam direction and the assist information not associated with the receive beam direction may be selectively used in the frequency band. For example, the base station device does not set the assist information associated with the reception beam direction at a frequency lower than 6 GHz. Further, for example, the base station device sets the assist information associated with the reception beam direction only at a frequency higher than 6 GHz.

Note that the CRI may be associated with the CSI resource set setting ID. When instructing the CRI to the terminal device, the base station device may instruct the CRI together with the CSI resource set setting ID. When the CSI resource set setting ID is associated with one CRI or one receiving beam direction, the base station device may set the assist information for each CSI resource set setting ID.

When the terminal equipment removes or suppresses inter-user interference, it is desirable for the base station equipment to instruct the terminal equipment that there is a possibility of multi-user transmission. Note that multi-user transmission that requires interference removal or suppression at the terminal device is also called multi-user MIMO transmission, multi-user superposition transmission, or NOMA (Non-Orthogonal Multiple Access) transmission. The base station apparatus can set multi-user MIMO transmission (MUST, NOMA) with an upper layer signal. When multi-user MIMO transmission (MUST, NOMA) is set, the base station apparatus can transmit interference signal information for removing or suppressing inter-user interference by DCI. The interference signal information included in the DCI is the existence of the interference signal, the modulation method of the interference signal, the DMRS port number of the interference signal, the number of DMRS CDM groups without the data of the interference signal, the power ratio of DMRS and PDSCH, and the DMRS arranged in front. Of symbols, information indicating OCC=2 or 4, and part or all of PT-RS information of an interference signal. Multi-user MIMO can be multiplexed up to 8 layers in

DMRS setting type

1 and 12 layers in DMRS setting type 2. Therefore, the maximum number of interference layers is 7 in DMRS setting type 1 and 11 in DMRS setting type 2. Therefore, for example, if there are 7 bits for DMRS setting type 1 and 11 bits for DMRS setting type 2, it is possible to indicate the presence of interference for each DMRS port number that may cause interference. If DMRS setting type 1 has 14 bits and DMRS setting type 2 has 22 bits, the presence of interference and three types of modulation schemes (for example, QPSK, 16QAM, 64QAM) are included for each DMRS port number that may cause interference. ) Can be shown.

Note that even if not removing or suppressing all the interference layers, removing or suppressing a part of the dominant interference signals can achieve the effect of removing or suppressing the interference signals. Therefore, the base station device can transmit the interference signal information for some interference layers. In this case, it is possible to reduce the control information amount for all the interference layers compared to transmitting the interference signal information. Moreover, the base station apparatus can set the maximum number of interference layers by the signal of the upper layer. In this case, the base station device transmits interference signal information regarding interference layers equal to or less than the maximum number of interference layers. At this time, the interference signal information includes information on the DMRS ports that are equal to or less than the maximum interference layer number. Therefore, it is possible to consider the trade-off between the effect of interference cancellation or suppression and the amount of control information depending on the maximum number of interference layers. In addition, the base station apparatus may set a DMRS port group that may cause interference with a higher layer signal. In this case, the maximum number of interference layers can be suppressed, and DMRS port numbers that can cause interference can be indicated. Also, the base station apparatus may set a DMRS CDM group that may cause interference with a signal of an upper layer. In this case, the maximum number of interference layers can be suppressed, and DMRS port numbers that can cause interference can be indicated. Also, the number of layers that can be multiplexed changes depending on the DMRS setting type and OCC=2 or 4. Therefore, the maximum number of layers can be associated with the DMRS setting type and OCC=2 or 4 that can be supported. In this case, the amount of control information can be reduced. For example, the maximum layer number of 4 can indicate OCC=2 in DMRS setting type 1. For example, the maximum layer number 6 can indicate OCC=2 in DMRS setting type 2. For example, the maximum number of layers 8 can indicate OCC=2 or 4 in DMRS setting type 1. For example, the maximum number of layers 12 can indicate OCC=2 or 4 in DMRS setting type 2. Note that the candidate DMRS port number of interference also changes when OCC=2 or 4. For example, in the case of DMRS setting type 1 and OCC=2, the DMRS port number that causes interference is the DMRS port number that is not used for its own device among the DMRS port numbers 1000, 1001, 1002, and 1003. When the DMRS setting type 2 is OCC=2, the DMRS port number is not used among the DMRS port numbers 1000, 1001, 1002, 1003, 1004 and 1005.

Also, the base station device classifies the assist information to be notified to the terminal device into first assist information and second assist information, and includes the number of information included in the first assist information and the second assist information. The number of information stored and the number of information stored can be different. In other words, the amount of information about the first interference signal notified by the base station device in the first assist information can be set to be larger than the amount of information about the second interference signal notified by the second assist information. For example, the base station apparatus can notify the information indicating the modulation multi-level number of the interference signal and the DMRS port as the first assist information, while notifying the information indicating the DMRS port as the second assist information. By controlling in this way, the base station apparatus suppresses the overhead related to the notification of the assist information, and the terminal apparatus uses the first assist information and the second assist information, so that the first interference signal and the first interference signal While it is possible to accurately generate the reception spatial filter considering the interference signal of No. 2 and to generate the replica signal of the first interference signal having large interference power, it is possible to implement the nonlinear interference canceller.

Note that the assist information notified by the base station device to the terminal device may be different depending on the frequency band in which the base station device sets the component carrier (or BWP). For example, PT-RS is highly likely to be transmitted by the base station device when performing high frequency transmission. Therefore, the base station device classifies the frequencies having the possibility of setting the component carrier into two frequency ranges, and the frequency range 1 (FR1) including the low frequency and the frequency range 2 (FR2) including the high frequency. The information amount of the assist information associated with the component carrier set to 1 can be made larger than the information amount of the assist information associated with the component carrier set to frequency range 1. For example, the base station device does not include the information about PT-RS in the assist information when performing communication by FR1, and includes the information about PT-RS in the assist information when performing communication by FR2.

PT-RS is also transmitted for each UE. Therefore, when the PT-RS is transmitted, the terminal device can know the number of PT-RS ports if it can know the number of UEs to be multiplexed. Further, since the PT-RS port is associated with the DMRS port, the control information increases as the number of PT-RS ports increases. Therefore, if the base station apparatus sets the maximum number of interfering UEs in the signal of the upper layer, the number of PT-RS ports can be limited and the amount of control information can be suppressed.

Also, since the existence of PT-RS is related to the modulation method (MCS), it is possible to limit the modulation method candidates depending on the presence or absence of PT-RS. For example, when the base station device sets the PT-RS setting, if the PT-RS is not transmitted, the modulation scheme of the interference signal is known to be QPSK, and if the PT-RS is transmitted, the interference signal is modulated. It can be seen that the scheme is 16QAM, 64QAM, or 256QAM. The PT-RS is highly likely to be transmitted in the high frequency band. In the high frequency band, the modulation multi-value number tends to be low. Therefore, in the case of multi-user transmission in the high frequency band (for example, the frequency band of 6 GHz or more), the modulation method may be QPSK. In multi-user transmission with a large number of spatially multiplexed signals, the modulation multilevel number tends to be low, and thus the modulation method may be QPSK. For example, when the maximum number of interference layers or the maximum number of interfering UEs exceeds a predetermined number, the modulation scheme may be QPSK. If the modulation method is QPSK, PT-RS is not transmitted, so that related control information can be reduced.

Also, the presence/absence of PT-RS depends on the number of allocated RBs. When the number of RBs set in the terminal device is less than a predetermined value (for example, 3), the base station device does not set PT-RS in the terminal device. Therefore, when the number of RBs assigned to the interference signal is less than the predetermined value, the terminal device can perform the interference suppression process on the assumption that PT-RS is not set in the interference signal. Further, in order to suppress the overhead related to the notification of the PT-RS setting information, when the set time density and/or frequency density of PT-RS is greater than or equal to a predetermined value, the base station The device may not include the PT-RS setting information in the assist information. The time density of PT-RS depends on the MCS setting. That is, if the MCS set in the interference signal is greater than or equal to a predetermined value, the base station apparatus can set not to notify the terminal apparatus of the PT-RS setting information associated with the interference signal. Also, the frequency density of the PT-RS depends on the scheduled bandwidth. That is, if the bandwidth set in the interference signal is less than the predetermined value, the base station apparatus can set not to notify the terminal apparatus of the PT-RS setting information associated with the interference signal.

The base station apparatus according to this embodiment can determine the MCS to be set in the PDSCH by referring to the multiple MCS tables. Therefore, when the interference information includes MCS, the base station apparatus can include information indicating the MCS table referenced by the index indicating the MCS in the interference information. Further, the terminal device assumes that the index indicating the MCS associated with the interference signal refers to the same MCS table as the MCS table referred to by the index indicating the MCS set in the PDSCH destined for the own device. Suppression processing can be performed. Similarly, the base station apparatus can include information indicating the codebook referred to by the index indicating the PMI in the interference information, and the terminal apparatus notifies the apparatus itself of the codebook referred to by the index indicating the PMI. The interference suppression processing can be performed assuming that the same codebook as the codebook referred to by the PMI to be referred to is referred to.

Further, when the base station device sets the PT-RS setting and the multi-user transmission setting, the terminal device may assume that the number of DMRS symbols arranged in front is 1 (OCC=2). In this case, the number of DMRS ports and port numbers that are candidates for interference can be limited by the PT-RS setting. Further, when the base station apparatus sets the PT-RS setting and the multi-user transmission setting and the number of DMRS symbols arranged in front of the own apparatus is 2, the terminal apparatus has no inter-user interference. You may assume.

Also, in order to suppress the control information related to the resource allocation of the interference signal (to another device), the resource allocation to the own device is preferably included in the resource allocation to the interference signal (to another device). Therefore, when multi-user transmission is set, the terminal device assumes some or all of the same PDSCH mapping type, the same DMRS setting type, and the same number of DMRS symbols to be arranged in the forward direction in the own device.

The frequency band used by the communication device (base station device, terminal device) according to the present embodiment is not limited to the licensed band and the unlicensed band described above. The frequency band targeted by this embodiment is not actually used due to the purpose of preventing interference between frequencies, etc., even though the country or region has given permission to use it for specific services. A frequency band called a white band (white space) (for example, a frequency band that is allocated for television broadcasting but is not used in some areas) or has been allocated exclusively to a specific carrier until now, It also includes a shared frequency band (licensed shared band) that is expected to be shared by multiple operators in the future.

The program that operates on the device related to the present invention may be a program that controls a Central Processing Unit (CPU) or the like to cause a computer to function so as to realize the functions of the embodiments related to the present invention. The program or information handled by the program is temporarily stored in a volatile memory such as Random Access Memory (RAM) or a non-volatile memory such as a flash memory, a Hard Disk Drive (HDD), or other storage device system.

The program for realizing the functions of the embodiments according to the present invention may be recorded in a computer-readable recording medium. It may be realized by causing a computer system to read and execute the program recorded in this recording medium. The “computer system” here is a computer system built in the apparatus and includes an operating system and hardware such as peripheral devices. Further, the "computer-readable recording medium" is a semiconductor recording medium, an optical recording medium, a magnetic recording medium, a medium that dynamically holds a program for a short time, or another computer-readable recording medium. Is also good.

Also, each functional block or features of the device used in the above-described embodiment may be implemented or executed by an electric circuit, for example, an integrated circuit or a plurality of integrated circuits. An electrical circuit designed to perform the functions described herein may be a general purpose processor, digital signal processor (DSP), application specific integrated circuit (ASIC), field programmable gate array (FPGA), or other. Programmable logic devices, discrete gate or transistor logic, discrete hardware components, or combinations thereof. A general purpose processor may be a microprocessor, conventional processor, controller, microcontroller, or state machine. The electric circuit described above may be formed of a digital circuit or an analog circuit. Further, in the event that an integrated circuit technology that replaces the current integrated circuit has emerged due to the progress of semiconductor technology, one or more aspects of the present invention can use a new integrated circuit according to the technology.

Note that the present invention is not limited to the above embodiment. Although an example of the apparatus is described in the embodiment, the present invention is not limited to this, and a stationary or non-movable electronic device installed indoors or outdoors, for example, an AV device, a kitchen device, It can be applied to terminal devices or communication devices such as cleaning/laundry equipment, air conditioning equipment, office equipment, vending machines, and other household appliances.

Although the embodiment of the present invention has been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment, and includes design changes and the like within a range not departing from the gist of the present invention. Further, the present invention can be variously modified within the scope of the claims, and embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention. Be done. Further, a configuration in which the elements described in each of the above embodiments and having the same effect are replaced with each other is also included.

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

Claims

A terminal device that communicates with a base station device,
A receiver for receiving channel state information (CSI) report settings and a channel state information reference signal (CSI-RS);
A CSI measuring unit for obtaining CSI using the CSI-RS,
A transmission unit that transmits the CSI to the base station device,
The CSI report settings include codebook settings for setting a Type 1 codebook or a Type 2 codebook,
When the type 2 codebook is set in the codebook setting, the CSI includes one of a type 1 CSI based on the type 1 codebook and a type 2 CSI based on the type 2 codebook,
Terminal device.
The CSI consists of CSI part 1 and CSI part 2,
The CSI part 1 includes information indicating whether the CSI part 2 includes the type 1 CSI,
If the CSI part 1 reports that it contains a type 1 CSI, the CSI part 2 reports a type 1 CSI,
When the CSI part 1 reports that the type 2 CSI is included, the CSI part 2 reports the type 2 CSI,
The terminal device according to claim 1.
The type 1 codebook is given a precoding matrix per layer with at least one vector and phase coefficients,
The type 2 codebook is provided with a precoding matrix per layer with at least a plurality of orthogonal vectors, wideband amplitude coefficients, and subband phase coefficients,
The CSI part 1 includes information indicating the number of non-zero wideband amplitude coefficients,
The information indicating the number of non-zero wideband amplitude coefficients indicates whether or not the CSI part 2 includes the type 1 CSI,
The terminal device according to claim 1.
The type 2 CSI includes a PMI compressed in the frequency domain,
The terminal device according to claim 1.
Select whether to report the type 1 CSI or the type 2 CSI based on a channel quality indicator (CQI),
The terminal device according to claim 1.
A base station device that communicates with a terminal device,
A channel state information (CSI) report setting, and a transmitter for transmitting a channel state information reference signal (CSI-RS);
A receiver for receiving the CSI from the terminal device,
The CSI report settings include codebook settings for setting a Type 1 codebook or a Type 2 codebook,
When the type 2 codebook is set in the codebook setting, the CSI includes one of a type 1 CSI based on the type 1 codebook and a type 2 CSI based on the type 2 codebook,
Base station device.
The CSI consists of CSI part 1 and CSI part 2,
The CSI part 1 includes information indicating whether the CSI part 2 includes the type 1 CSI,
When it is received that the CSI part 1 includes the type 1 CSI, the CSI part 2 receives the type 1 CSI,
If the CSI part 1 receives a type 2 CSI, the CSI part 2 receives a type 2 CSI.
The base station device according to claim 6.
The type 1 codebook is given a precoding matrix per layer with at least one vector and phase coefficients,
The type 2 codebook is provided with a precoding matrix per layer with at least a plurality of orthogonal vectors, wideband amplitude coefficients, and subband phase coefficients,
The CSI part 1 includes information indicating the number of non-zero wideband amplitude coefficients,
The information indicating the number of non-zero wideband amplitude coefficients indicates whether or not the CSI part 2 includes the type 1 CSI,
The base station device according to claim 6.
The type 2 CSI includes a PMI compressed in the frequency domain,
The base station device according to claim 6.
A communication method in a terminal device communicating with a base station device, comprising:
Receiving channel state information (CSI) report settings and channel state information reference signal (CSI-RS);
Determining CSI using the CSI-RS,
Transmitting the CSI to the base station apparatus,
The CSI report settings include codebook settings for setting a Type 1 codebook or a Type 2 codebook,
When the type 2 codebook is set in the codebook setting, the CSI includes one of a type 1 CSI based on the type 1 codebook and a type 2 CSI based on the type 2 codebook,
Communication method.
A communication method in a base station device for communicating with a terminal device, comprising:
Transmitting channel state information (CSI) report settings and channel state information reference signals (CSI-RS);
Receiving the CSI from the terminal device,
The CSI report settings include codebook settings for setting a Type 1 codebook or a Type 2 codebook,
When the type 2 codebook is set in the codebook setting, the CSI includes one of a type 1 CSI based on the type 1 codebook and a type 2 CSI based on the type 2 codebook,
Communication method.