TWI841285B - Methods for multiple-transmission-reception-point measurement and transmission、apparatus and storage medium thereof - Google Patents

Abstract

A method of channel state information (CSI) report can include receiving a CSI report configuration at a user equipment (UE) from a base station, the CSI report configuration being associated with a set of CSI reference signal (CSI-RS) resources corresponding to multiple transmission reception points (TRPs), performing a channel measurement based on the CSI-RSs resources corresponding to the multiple TRPs, determining a precoder matrix indicator (PMI) based on measurement results of the channel measurement, the PMI corresponding to a precoder matrix, denoted W , of a Type II CSI codebook, the precoder matrix having a spatial domain (SD) basis vector matrix, denoted W ₁ , SD basis selection of the SD basis vector matrix being TRP-specific, and transmitting a CSI report to the base station, the CSI report including the PMI.

Description

Measurement and transmission method, device and storage medium for multiple sending and receiving points

Embodiments of the present invention generally relate to wireless mobile communications, and, more particularly, to multi-antenna transmission operations at network and mobile devices in wireless communication systems.

A large number of steerable antenna units can be used for transmission and reception on the network side or the device side. In higher frequency bands, a large number of antenna units can be used for beamforming to extend coverage. In lower frequency bands, a large number of antenna units can be used to spatially separate users to increase the transmission capacity of the spectrum. Channel state information (CSI) for operation of large-scale multi-antenna schemes can be obtained through feedback of CSI reports, where CSI reports are based on the transmission of reference signals in the downlink or uplink between the network and the mobile device.

Aspects of the present invention provide a first method for CSI reporting. The first method includes: receiving a CSI report configuration at a user equipment (UE) from a base station, the CSI report configuration being associated with a CSI reference signal (CSI-RS) resource set corresponding to a plurality of transmission reception points (TRPs); performing channel measurement based on the CSI-RS resources corresponding to the plurality of TRPs; determining a precoder matrix indicator (PMI) based on the measurement results of the channel measurement, the PMI corresponding to a precoder matrix denoted as W of a type II CSI codebook; the precoder matrix having a spatial domain (SD) basis vector matrix denoted as W ₁ , the SD basis selection of the SD basis vector matrix being TRP-specific; and sending a CSI report to the base station, the CSI report including the PMI.

其中，N _T 是複數個TRP的天線埠的數目，L是對應於 W ₁ 中的一個天線極化的基向量的數目，N _P 是複數個TRP的數目，

是第p個TRP的SD基向量矩陣，p=1,...N _P 。

是SD基矩陣並且具有以下形式

其中，

是第p個TRP的天線埠的數目，p=1,...N _P ，並且L _p 是第p個TRP的每個極化中的SD基向量的數目，使得

並且

。 In one implementation, the SD basis vector matrix has the following form:

Where, NT is the number of antenna ports of the _{plurality of TRPs, L is the number of basis vectors corresponding to one antenna polarization in W1, NP} is the _{number of} plurality of TRPs,

is the SD basis vector matrix of the p-th TRP, p = 1,... N _P .

is an SD basis matrix and has the form

in,

is the number of antenna ports of the p-th TRP, p = 1,... N _P , and L _p is the number of SD basis vectors in each polarization of the p-th TRP, such that

And

.

In one embodiment, the SD basis vector matrix includes TRP-specific SD basis matrices, each SD basis matrix corresponding to one of a plurality of TRPs. In one embodiment, the SD basis vector matrix includes TRP-specific SD basis matrices, each SD basis matrix corresponding to one of a plurality of TRPs, and the TRP-specific SD basis matrices have different numbers of SD basis vectors. For example, one of the TRP-specific SD basis matrices includes a first basis vector of a first polarization of the corresponding TRP and a second basis vector of a second polarization of the corresponding TRP, the first basis vector being the same as the second basis vector.

In one embodiment, the SD basis selection of the SD basis vector matrix is layer-common. In one embodiment, the SD basis vector matrix includes SD basis vectors corresponding to different TRPs in a plurality of TRPs, and co-located TRPs in the plurality of TRPs have the same SD basis vectors. In one embodiment, the PMI includes an indication of SD basis vectors contained in the SD basis vector matrix, the SD basis vectors corresponding to corresponding TRPs in the plurality of TRPs, wherein two co-located TRPs in the plurality of TRPs share the same set of SD basis vectors in the SD basis vectors in the PMI. In an example, the method further includes: in response to receiving an indication from a base station as to which TRPs in the plurality of TRPs are co-located, determining based on the indication to report the same set of SD basis vectors for the two co-located TRPs. In the example, the method further includes determining that the same set of SD basis vectors are reported for two co-localized TRPs based on the calculated SD basis vectors corresponding to different TRPs.

Aspects of the present invention provide a first device including a circuit. The circuit is configured to receive a CSI report configuration from a base station, the CSI report configuration being associated with a CSI-RS resource set corresponding to a TRP; perform channel measurement based on the CSI-RS resources corresponding to the plurality of TRPs; determine a PMI based on the measurement results of the channel measurement, the PMI corresponding to a precoder matrix of a type II CSI codebook, the precoder matrix having an SD basis vector matrix, the SD basis selection of the SD basis vector matrix being TRP-specific; and send a CSI report to the base station, the CSI report including the PMI.

Aspects of the present invention provide a first non-transitory computer-readable medium storing instructions that, when executed by a processor, cause the processor to perform the first method.

Aspects of the present invention provide a second method for CSI reporting. The second method includes: receiving a CSI report configuration from a base station at a UE, the CSI report configuration being associated with a CSI-RS resource set corresponding to a plurality of TRPs; performing channel measurement based on the CSI-RS resources corresponding to the plurality of TRPs; determining a first PMI based on a measurement result of the channel measurement, the first PMI corresponding to a first precoder matrix denoted as W of a type II CSI codebook, the first precoder matrix having a first SD/frequency domain (FD) coefficient matrix denoted as W2 , the coefficient row in the first SD/FD coefficient matrix corresponding to the first SD/FD coefficient matrix denoted as W ₁ , the coefficient rows (columns) in the first SD/FD coefficient matrix correspond to the FD basis vectors in the FD basis vector matrix, the first PMI includes a first FD basis indicator, the first FD basis indicator indicates that the FD basis selection corresponding to any TRP in the first SD/FD coefficient matrix is independent of the FD basis selection of any other TRP; and sending a CSI report to the base station, the CSI report including the first PMI.

In one embodiment, the first FD basis indicator includes an initial window position indicator and an FD basis index for each of the plurality of TRPs. In one embodiment, the method further includes determining a second PMI, the second PMI being based on a second precoder matrix of a type II CSI codebook, the second precoder matrix having a second SD/FD coefficient matrix, the second PMI including a second FD basis indicator, the second FD basis indicator indicating that the FD basis selection in the second SD/FD coefficient matrix is common to the plurality of TRPs. In one example, the second FD basis indicator includes only one initial window position indicator and only one FD basis index for the plurality of TRPs.

In one embodiment, non-zero-coefficients (NZCs) are selected from a first SD/FD coefficient matrix across a plurality of TRPs. In one embodiment, the strongest coefficients are selected from a first SD/FD coefficient matrix across a plurality of TRPs. In one embodiment, reference amplitude coefficients are selected from a first SD/FD coefficient matrix across a plurality of TRPs.

In one embodiment, a TRP-specific reference amplitude coefficient is selected from a first SD/FD coefficient matrix. In one example, the TRP-specific reference amplitude coefficient is polarization-common. In one example, the TRP-specific reference amplitude coefficient is polarization-specific. In one embodiment, the PMI includes a TRP-common NZC bitmap indicating NZC positions in the first SD/FD coefficient matrix. In one embodiment, the PMI includes a TRP-specific NZC bitmap indicating NZC positions in the first SD/FD coefficient matrix.

Aspects of the present invention provide a second device including a circuit. The circuit is configured to receive a CSI report configuration from a base station, the CSI report configuration being associated with a CSI-RS resource set corresponding to a plurality of TRPs; perform channel measurement based on the CSI-RS resources corresponding to the plurality of TRPs; determine a first PMI based on a measurement result of the channel measurement, the first PMI corresponding to a first precoder matrix denoted as W of a type II CSI codebook, the first precoder matrix having a first SD/FD coefficient matrix denoted as W ₂ , the coefficient columns in the first SD/FD coefficient matrix corresponding to the first PMI denoted as W ₁ , the coefficient rows in the first SD/FD coefficient matrix correspond to the FD basis vectors in the FD basis vector matrix, the first PMI includes a first FD basis indicator, the first FD basis indicator indicates that the FD basis selection corresponding to any TRP in the first SD/FD coefficient matrix is independent of the FD basis selection of any other TRP; and sending a CSI report to the base station, the CSI report including the first PMI.

Aspects of the present invention provide a second non-transitory computer-readable medium storing instructions that, when executed by a processor, cause the processor to perform the second method.

Aspects of the present invention provide a third method for CSI reporting. The third method includes: receiving a CSI report configuration from a base station at a UE, the CSI report configuration being associated with a CSI-RS resource set corresponding to a plurality of TRPs, the CSI-RS resources being organized into one or more resource groups, the CSI report configuration including one or more antenna configurations (N ₁ , N ₂ ), each antenna configuration corresponding to one or more of the plurality of TRPs, and the one or more antenna configurations (N ₁ , N ₂ ) corresponding to the one or more resource groups, respectively. _N1 and _N2 are the numbers of antenna ports of the one or more TRPs in the vertical and horizontal directions, respectively; performing channel measurement based on the CSI-RS resources corresponding to the multiple TRPs; determining the PMI based on the measurement result of the channel measurement and the one or more antenna configurations ( _N1 , _N2 ) corresponding to one or more TRPs in the multiple TRPs; and sending a CSI report to the base station, wherein the CSI report includes the PMI.

In one embodiment, the PMI corresponds to a precoder matrix of a type II CSI codebook. In one embodiment, a first antenna configuration (N ₁ , N ₂ ) among one or more antenna configurations (N ₁ , N ₂ ) corresponds to at least two co-located TRPs among a plurality of TRPs, and N ₁ and N ₂ are the number of antenna ports in the vertical and horizontal directions of each co-located TRP, respectively. In one embodiment, the CSI report configuration further includes a power indicator indicating how to adjust the transmission power of a TRP among the plurality of TRPs. For example, the UE performs a channel-quality indicator (CQI) estimation based on the power indicator.

In one embodiment, the CSI report configuration further includes a power indicator indicating which of the plurality of TRPs share the same total power. In one embodiment, the CSI report configuration further includes a power indicator indicating that at least one of the plurality of TRPs is transmitted at full power. In one embodiment, the CSI report configuration further includes a power indicator indicating that each of the plurality of TRPs is transmitted at full power.

Aspects of the present invention provide a third device including a circuit. The circuit is configured to receive a CSI report configuration from a base station at a UE, the CSI report configuration being associated with a CSI-RS resource set corresponding to a plurality of TRPs, the CSI-RS resources being organized into one or more resource groups, the CSI report configuration comprising one or more antenna configurations ( _N1 , _N2 ), each antenna configuration corresponding to one or more of the plurality of TRPs, the one or more antenna configurations ( _N1 , _N2 ) corresponding to the one or more resource groups, respectively. _N1 and _N2 are the numbers of antenna ports of the one or more TRPs in the vertical and horizontal directions, respectively; performing channel measurement based on the CSI-RS resources corresponding to the multiple TRPs; determining the PMI based on the measurement result of the channel measurement and the one or more antenna configurations ( _N1 , _N2 ) corresponding to one or more TRPs in the multiple TRPs; and sending a CSI report to the base station, wherein the CSI report includes the PMI.

Aspects of the invention provide a third non-transitory computer-readable medium storing instructions that, when executed by a processor, cause the processor to perform the method.

601: Modulation symbol layer

602: Precoder

603: Antenna port

604: Space filter

605: Physical antenna

700,800,911,912,913,914,1002,1003,1101:TRP

701,801,802,803,804: Antenna panel

900: Example

901,1001,1102,1901:UE

1100,3300,3400,3500:Process

S1110,S1120,S1130,S1140,S1150,S1160,S3301,S3310,S3320,S3330,S3340,S3399,S3401,S3410,S3420,S3430,S3440,S3499,S3501,S3510,S3520,S3530,S3540,S3599: Steps

1601,1602,1603,1604,1701,1702,1703,1704:Scenes

2000: Precoder structure

2001,2201,2202,2203,2204,2301,2302,2303,2304,2305: coefficient

3600:Device

3610: Processing circuit

3620:Memory

3630:RF module

3640: Antenna array

The present invention proposes some implementation methods as examples, which will be described in detail below with reference to the accompanying figures, where the same numbers represent the same components, wherein: Figures 1 to 3 show examples of mapping a CSI-RS port or a sounding reference signal (SRS) port to a physical antenna.

Figure 4 shows a linear multi-antenna transmission scheme in a transmitter according to an embodiment of the present invention.

Figure 5 shows an example of analog multi-antenna processing.

FIG. 6 shows an example of hybrid multi-antenna processing according to some embodiments of the present invention.

Figure 7 shows a first example of a single TRP (sTRP) transmission.

Figure 8 shows a second example of sTRP transmission.

Figure 9 shows an example 900 of a multiple-TRP (mTRP) transmission according to an embodiment of the present invention.

Figure 10 shows an example of coherent joint transmission (CJT) of two TRPs 1002-1003.

Figure 11 shows a CSI measurement and reporting process 1100 according to an implementation of the present invention.

Figures 12A and 12B show examples of resource group configurations.

Figures 13A to 13B show examples of CSI-RS resource configuration for mTRP CJT reporting only (without reporting for sTRP).

Figures 14A to 14B show examples of CSI-RS resource configuration for mTRP CJT reporting only (without reporting for sTRP).

Figures 15A to 15B show examples of CSI-RS resource configuration for joint reporting of sTRP and mTRP CJT, sTRP CSI reporting, or mTRP CSI reporting.

Figure 16 shows a first example of W1 feedback reduction. As shown, 4 TRPs from TRP1 to TRP4 are deployed.

Figure 17 shows a second example of W1 feedback reduction.

Figure 18 shows an example of reporting the compressed SD basis vector matrix.

Figure 19A shows the switching between sTRP and mTRP.

Figure 19B shows another example of _W1 feedback reduction in the scenario of mixed sTRP and mTRP CSI reporting in Figure 19A.

Figure 20 shows the Type II codebook precoder structure 2000 for mTRP CJT feedback.

Figure 21 shows an example of NZC selection according to an embodiment of the present invention.

Figures 22A to 22B illustrate examples of NZC selection for mTRP CSI reporting according to an embodiment of the present invention.

Figures 23A-23B illustrate another example of NZC selection for mTRP CSI reporting according to an embodiment of the present invention.

Figure 24 shows an example of an alternative FD basis vector selection scheme according to an embodiment of the present invention.

FIG. 25 shows an example of the initial window position and the FD base index in the FD coefficient matrix W2 .

Figure 26 shows an example where different mTRP sets can be switched to serve the UE due to the mobility of the UE.

Figure 27 shows two types (two variants) of codebook structures for CSI feedback.

Figure 28A shows an example of a CSI reporting configuration.

Figure 28B shows an example of codebook configuration.

Figures 29A to 29B show examples of 4 TRP CJT transmission scenarios.

Figures 30A to 30B show examples of 4 TRP CJT transmission scenarios.

Figure 31 shows an example where the gNB can derive the SD/FD basis from the joint mTRP channel.

Figure 32 shows an example where the UE can select K1 ports from the PCSI-RS ports in a polarized and free manner.

FIG. 33 illustrates a process 3300 for measuring and reporting mTRP CSI according to an embodiment of the present invention.

FIG. 34 illustrates another process 3400 for mTRP CSI measurement and reporting according to an embodiment of the present invention.

FIG. 35 illustrates another process 3500 for mTRP CSI measurement and reporting according to an embodiment of the present invention.

FIG. 36 shows an exemplary device 3600 according to an embodiment of the present invention.

I.Multi-antenna operation

1. Reference signal and channel status information (CSI)

In some implementations, knowledge of the radio link may be obtained by measuring a reference signal transmitted on the radio link during a channel sounding process. The reference signal in the downlink direction may be referred to as a CSI-RS. The reference signal in the uplink direction may be referred to as an SRS.

The CSI-RS can be configured on a device-by-device basis. The configured CSI-RS can correspond to one or more different antenna ports (referred to as CSI-RS ports). Each CSI-RS port can correspond to a channel to be detected. For example, a multi-port CSI-RS can include 32 per-antenna-port CSI-RSs transmitted orthogonally on 32 CSI-RS ports. The per-antenna-port CSI-RS corresponds to a CSI-RS port.

CSI-RS can be configured for a specific bandwidth (e.g., a bandwidth portion). Within the configured bandwidth, CSI-RS can be configured for every N resource blocks. N can be 1, 2, 3, etc. Within a resource block, CSI-RS can occupy a set of one or more element resources within a time slot. For multi-port CSI-RS, the set of element resources is shared by multiple CSI-RS per antenna port, such as a combination based on code-domain sharing (CDM), frequency-domain sharing (FDM), or time-domain sharing (TDM).

A device may be configured with one or more CSI-RS resource sets. For example, a device may receive a CSI resource configuration that specifies one or more CSI-RS resource sets. Each resource set includes one or more configured CSI-RSs. Each resource set also includes a pointer to a set of New Radio (NR) synchronization signal (SS) blocks. CSI-RS resource sets may be configured for periodic, semi-persistent, or aperiodic transmissions. For example, semi-persistent CSI-RS transmissions may be activated or deactivated based on a MAC control element (CE). Aperiodic CSI-RS transmissions may be triggered by means of downlink control information (DCI).

Similarly, SRS can support one or more antenna ports (referred to as SRS ports). Different SRS ports of SRS can share the same set of resource elements and the same base SRS sequence. Different rotations can be applied to separate different SRS ports. Applying a phase rotation (or phase shift) in the frequency domain is equivalent to applying a cyclic shift in the time domain. Similar to CSI-RS, a device can be configured with one or more SRS resource sets. Each resource set can include one or more configured SRS. SRS resource sets can be configured for periodic transmission, semi-persistent transmission (controlled by MAC CE), or non-periodic transmission (triggered by DCI).

Figures 1 to 3 show examples of mapping CSI-RS ports or SRS ports to physical antennas. In the example of Figure 1, M ports of CSI-RS or SRS (CSI-RS/SRS) correspond to M antenna ports (CSI-RS ports or SRS ports). The M antenna ports are connected to N physical antennas through a spatial filter (marked as F). The M ports of CSI-RS/SRS are processed by the spatial filter before being mapped to the N physical antennas. Due to the spatial filtering, one or more transmission beams can be formed for the transmission of the M ports of CSI-RS/SRS. Generally, N can be greater than M.

In the example of Figure 2, two separate spatial filters F1 and F2 are applied to two CSI-RS/SRS #1 and #2, but are transmitted through the same set of physical antennas at the same time or at different times. Due to the spatial filtering, the two CSI-RS/SRS #1 and #2 are beamformed in different directions.

In the example of Figure 3, multiple antenna panels are used for transmission. The two CSI-RS/SRS #1 and #2 are processed by two separate spatial filters F1 and F2 and transmitted simultaneously or at different times on two antenna panels P1 and P2 respectively. Due to the spatial filtering and the corresponding antenna panels, the two CSI-RS/SRS #1 and #2 are beamformed in different directions.

As shown in the examples of Figures 1 to 3, the channel detected based on CSI-RS/SRS is not a physical radio channel but a channel corresponding to a CSI-RS port or an SRS port.

In some implementations, a network (e.g., a base station) may configure a CSI reporting configuration to a device. The device may perform channel measurement based on the CSI reporting configuration and report the measurement results to the network. For example, the CSI reporting configuration may specify a set of quantities to be reported. The quantities may include CQI, rank indicator (RI), PMI, etc. These quantities are collectively referred to as CSI. The quantities also include a reference-signal received power (RSRP) that reflects the received signal strength.

The CSI reporting configuration may further specify downlink resources that may be measured to derive the specified quantity. For example, the CSI reporting configuration may describe or indicate one or more CSI-RS resource sets, each comprising one or more CSI-RS. For example, a single multiport CSI-RS may be configured to report a combination of CQI, RI, and PMI for link adaptation and multi-antenna precoding. Multiple CSI-RS may be configured for beam management, and each CSI-RS may be beamformed and transmitted in different directions. In some scenarios, the device may perform measurements without reporting based on the configured resources. For example, the device may perform measurements for receiver-side beamforming and multi-antenna precoding without reporting.

The reporting configuration may further describe when and how the reporting is performed. For example, the reporting may be periodic, semi-persistent, or aperiodic. The reporting may be enabled (disabled) based on MAC CE or triggered by DCI. The measurement results for periodic and semi-persistent reporting may be carried in the physical uplink control channel (PUCCH). The measurement results for aperiodic reporting may be carried in the physical uplink shared channel (PUSCH).

2. Multi-antenna transmission

A Digital and analog multi-antenna processing

FIG. 4 shows a linear multi-antenna transmission scheme in a transmitter according to an embodiment of the present invention. As shown, _NL layers of data (e.g., modulation symbols) are mapped to _NT transmit antennas by multiplying with a transmission matrix W of size _NT × _NL . Vector X represents _NL layers of data. Vector Y represents _NT signals corresponding to _NT antennas.

In various examples, the multi-antenna processing represented by the matrix W can be applied to the analog portion of the transmission chain or the digital portion of the transmission chain. Alternatively, a hybrid scheme can be adopted, in which the multi-antenna processing can be applied to both the analog and digital portions of the transmission chain. Thus, in various implementations, the multi-antenna processing can be analog multi-antenna processing, digital multi-antenna processing, or hybrid multi-antenna processing.

In the case of analog processing, a spatial filter F may be applied to provide antenna-by-antenna phase shifting to form the transmit beam. FIG. 5 shows an example of analog multi-antenna processing. In some examples, analog processing is performed on a carrier-by-carrier basis for downlink transmissions. Thus, no frequency multiplexing beamformed transmissions are performed for devices located at different directions relative to the base station. To cover different devices located at different directions, beam scanning is performed by analog processing.

In the case of digital processing, each element of the transmit matrix W can include phase shifts and scaling factors, which provides greater flexibility in controlling the beamforming direction. For example, simultaneous multi-beam-beamforming can be achieved to cover multiple devices located in different directions relative to the base station. The transmit matrix W used in digital multi-antenna processing is called the precoder matrix. The corresponding multi-antenna processing is called multi-antenna precoding.

Precoders and spatial filters can be connected in sequence in hybrid multi-antenna processing to form directional transmission beams. Figure 6 shows an example of hybrid multi-antenna processing according to some embodiments of the present invention. As shown, the modulation symbol layer 601 is mapped to the CSI-RS antenna port 603 through the precoder 602. The output from the precoder 602 is mapped to the physical antenna 605 through the spatial filter (F) 604. In some examples, the spatial filter 604 is used to form a wider beam, and the precoder 602 is used to form one or more narrower beams along the direction of the wider beam. By selecting a specific precoder 602 and spatial filter 604, the transmitter can determine one or more beams to cover one or more receivers distributed at different locations.

Similar to transmitter-side processing, the receiver can apply analog, digital, or hybrid multi-antenna processing for beamforming reception of signals arriving from different directions.

B. Downlink multi-antenna precoding

In some implementations, to support network selection of a precoder for downlink transmission (e.g., physical downlink shared channel (PDSCH) transmission), a device may perform measurements based on CSI-RS and report measurement results (e.g., CSI reports) to the network based on a configuration (e.g., CSI report configuration) received from the network. The network may then determine a precoder based on the measurement results.

In some examples, the CSI report may include RI, PMI, COI, etc. RI may indicate the appropriate transmission rank (number of transmission layers _NL ) for downlink transmission. PMI may indicate the appropriate precoder matrix M corresponding to the selected rank. Given the selected precoder matrix, CQI may indicate the appropriate channel coding rate and modulation scheme.

In some implementations, the value of the PMI may correspond to a particular precoder matrix selected from a precoder codebook. The precoder codebook provides a set of candidate precoder matrices. In addition to the number of transmission layers _NL , the device also selects the PMI based on a particular number of antenna ports ( _NRs ) of configured CSI-RS associated with the CSI reporting configuration. In one example, at least one codebook is provided for each valid combination of _NT and _NL .

In some implementations, two types of CSI are defined corresponding to different scenarios: Type I CSI and Type II CSI. Different types of CSI are associated with different sets of precoder codebooks with different structures and sizes.

The codebook for Type I CSI can be relatively simple and aims to focus the transmitted energy at the target receiver. Type I CSI can include two subtypes: Type I single-panel CSI and Type I multi-panel CSI. The two subtypes correspond to different antenna configurations on the network or transmitter side. The codebook for Type II CSI can provide channel information with higher spatial subtlety than Type I CSI. Type II CSI can target multi-user Multiple-Input Multiple-Output (MIMO) (MU-MIMO) scenarios.

II. Type II CSI codebook structure

In some implementations, Type II CSI feedback may be based on a linear combination (LC) codebook. For example, the eigenvectors of a channel may be represented (approximately) as a linear combination of L Discrete Fourier Transform (DFT) vectors. The UE may report CSI including the DFT vectors and the coefficients used to combine the DFT vectors. If the channel has multiple primary eigenvectors (higher rank channels), the UE may report multiple eigenvectors. The DFT of the DFT vectors may be reported in a wideband (WB) manner (one common report for all subbands (SB)) beam. The magnitude and phase of the coefficients may be reported separately using the corresponding codebook. For example, the coefficient phase may be frequency selective and therefore reported for each SB. The coefficient magnitude may be reported in a WB manner.

其中，對於極化r和秩l，w _r,l 是逐個極化的L個正交波束的加權線性組合。加權向量W可以如下確定。DFT波束矩陣W ₁ 可以具有2N ₁ N ₂ ×2L的大小，其中，可以逐個極化從一組過採樣的O ₁ O ₂ N ₁ N ₂ 個DFT波束中選擇L個正交向量/波束。N ₁ 和N ₂ 是水平和垂直域中相同極化方向的天線埠的數目。O ₁ 和O ₂ 是相應維度中的過採樣因數。L個正交向量的線性組合實現了空間域(SD)中的壓縮。L個正交向量可稱為SD分量或SD基。線性組合子帶矩陣W ₂ 可以確定成使得對於每個子帶，W ₁ 的列的加權線性組合產生通道協方差矩陣的l個最強特徵向量。可以看出，當層和子帶的數目增加時，組合係數的數目會線性增加，從而導致大的CSI報告開銷。 In some implementations, the weight vector (or precoder matrix) for rank-1 type II CSI may have the following form:

Where, for polarization r and rank l , w _{r , l} is a weighted linear combination of L orthogonal beams polarized one by one. The weight vector W can be determined as follows. The DFT beam matrix W ₁ can have a size of 2N ₁ N ₂ × 2L , where L orthogonal vectors/beams can be selected polarization by polarization from a set of oversampled O ₁ O ₂ N ₁ N ₂ DFT beams. N ₁ and N ₂ are the number of antenna ports of the same polarization direction in the horizontal and vertical domains. O ₁ and O ₂ are the oversampling factors in the corresponding dimensions. The linear combination of L orthogonal vectors achieves compression in the spatial domain (SD). The L orthogonal vectors can be called SD components or SD basis. The linear combination subband matrix W2 can be determined such that for each subband, the weighted linear combination of the columns _of W1 produces the l strongest eigenvectors of the channel covariance matrix. It can be seen that when the number _of layers and subbands increases, the number of combining coefficients increases linearly, resulting in large CSI reporting overhead.

：

壓縮矩陣W _f 可以被認為是用於頻率壓縮的SD基矩陣W ₁ 的等效物。因此，類型II CSI預編碼器矩陣可以具有如下格式：

內的元素可以稱為FD係數。在頻率壓縮之後，FD係數矩陣

可以是稀疏的。 而且，大部分能量集中在幾個係數中。因此，可以確定

中的用於報告的幾個最重要的FD係數。其餘可以假定為零。 In some implementations, the type II CSI precoder is further compressed by exploiting frequency domain (FD) correlation within W _2. DFT compression may be applied on W _2. For example, W ₂ may have a size of 2L × N ₃ , where 2L is the number of SD beams and N ₃ is the number of subbands. A frequency compression matrix W _f may be determined by selecting a set of orthogonal vectors from the columns of an oversampled DFT codebook. The matrix W _f may have a size of N ₃ × M ( M < N ₃ ). M is the number of FD basis vectors selected after compression. FD compression may be applied to each layer to obtain a linear combination coefficient matrix

:

The compression matrix Wf can be considered as the equivalent of _the SD base matrix W1 used for frequency compression. Therefore _, the type II CSI precoder matrix can have the following format:

The elements in can be called FD coefficients. After frequency compression, the FD coefficient matrix

can be sparse. Moreover, most of the energy is concentrated in a few coefficients. Therefore, it can be determined

The most important FD coefficients are reported in . The rest can be assumed to be zero.

III. Single TRP and Multiple TRP Deployment

In the present invention, the terms "transmit receive point (TRP)", "antenna panel (or panel)", "antenna group (or port group)", "cell" and "magnetic sector" can be used interchangeably to refer to antennas located at the same location. The technology, method, processing, process, example or implementation disclosed using TRP or panel as an example can also be applied to antenna group, cell or magnetic sector. In deployment, a magnetic sector can correspond to one or more cells, a cell can correspond to one or more TRPs, and a TRP can correspond to one or more antenna panels. However, each of the magnetic sector, cell, TRP or panel can be regarded as a group of antennas for applying the technology disclosed herein.

1. Single TRP deployment

Figure 7 shows a first example of a single TRP (sTRP) transmission. TRP 700 is configured with a single antenna panel 701. Antenna panel 701 includes a 32-port square (or rectangular) antenna array. The antenna array has a horizontal dimension of _N1 =4 and a vertical dimension of _N2 =4. _N1 and _N2 are the number of cross-polarization antenna units. Each cross-polarization antenna unit includes two cross-polarization antennas. Each cross-polarization antenna unit can correspond to a pair of well-isolated spatial paths for diversity or spatial multiplexing. Antennas located at the same position of antenna panel 701 allow the same DFT basis vectors to be used on the polarization in the precoder matrix. These DFT basis vectors can be linearly combined for a near-optimal precoder. Examples of suitable codebooks for the single TRP transmission example of FIG. 7 may include the Third Generation Partnership Project (3GPP) Release 15 Type I codebook, Release 15 Type II codebook, and Release 16e Type II codebook for a single board.

Figure 8 shows a second example of sTRP transmission. TRP 800 is configured with 4 antenna panels 801-804. Each antenna panel 801 includes a 32-port square (or rectangular) antenna array. The size of the antenna array is ( _N1 , _N2 ) = (4, 4). The spacing between the last antenna unit of the first panel and the first antenna unit of the next panel is different from the antenna unit spacing within each antenna panel 801-804. Therefore, a suitable precoder may include a _W1 matrix and a _W2 matrix. The _W1 matrix defines a beam for each polarization and panel. The _W2 matrix provides the same phase between the co-polarizations of each subband and the same phase between panels. An example of a suitable codebook for multi-panel single TRP transmission in the example of Figure 8 may include a 3GPP Release 15 Type I codebook for multiple panels.

2. Multi-TRP deployment

Multiple widely spaced (distributed) transmitter-receiver points (TRPs) can operate in CJT mode or non-coherent joint transmission (NCJT). In NCJT, different layers can be transmitted from multiple TRPs without coordination between the multiple TRPs. Inter-layer interference can reduce throughput and coverage. In CJT, multiple TRPs can be controlled to operate in a coordinated manner. Therefore, signals from different TRPs can constructively interfere with each other to improve throughput and coverage, and inter-layer interference can be reduced. To support CJT of multiple TRPs, the in-phase and amplitude (or power) differences between the TRPs can be measured and reported from the mobile device to the network. Based on this reported information, the network can control the TRPs to perform coherent joint transmission. Therefore, mTRP CJT CSI measurement and reporting schemes are adopted in various implementations disclosed in this article. These schemes may include new mechanisms for CSI-RS configuration, CSI reporting configuration, and CJT codebook structure.

FIG. 9 shows an example 900 of mTRP transmission according to an embodiment of the present invention. UE 901 receives CSI-RS signals from four TRPs 911-914. Each TRP may be configured with one or more antenna panels. These TRPs 911-914 may be controlled by the same base station (e.g., gNB) and may operate in coordination for CJT. Due to the geographical distribution of TRPs 911-914, the synchronization signals sent from TRPs 911-914 to UE 901 may take different paths. In order to enable TRPs 911-914 to operate in CJT mode, a CSI measurement and reporting process may be performed between TRPs 911-914 and UE 901. Based on the reported CSI, CJT of TRPs 911-914 may be implemented.

(v個層)。TRP 1 1002具有

個發送(transmission，tx)埠，TRP 2 1003具有

個tx埠。tx埠的總有效數目是

。從TRP 1 1002到UE 1001的下行鏈路(DL)通道是

。從TRP 1 1002到UE 1001的預編碼器是

。從TRP 2 1003到UE 1001的DL通道是

。從TRP 2 1003到UE 1001的預編碼器是

。因此，在UE 1001處接收的訊號可以是

其中，

和

是有效通道矩陣和有效預編碼器矩陣。 FIG. 10 shows an example of a CJT of two TRPs 1002-1003. The system model is described below with reference to FIG. 10. The two TRPs 1002-1003 are configured to jointly send signals to _{a UE 1001 having NR} reception (rx) ports.

( v layers). TRP 1 1002 has

Transmission (tx) ports, TRP 2 1003 has

tx ports. The total valid number of tx ports is

The downlink (DL) path from TRP 1 1002 to UE 1001 is

The precoder from TRP 1 1002 to UE 1001 is

The DL channel from TRP 2 1003 to UE 1001 is

The precoder from TRP 2 1003 to UE 1001 is

Therefore, the signal received at UE 1001 may be

in,

and

are the effective channel matrix and the effective precoder matrix.

3. mTRP CJT CSI reporting process

FIG. 11 shows a CSI measurement and reporting process 1100 according to an embodiment of the present invention. In process 1100, CSI is reported from UE 1102 to base stations connected to a set of geographically distributed TRPs 1101. Process 1100 may include 6 steps from step S1110 to step S1160.

In step S1110, the network (or base station) may use radio resource control (RRC) signaling to indicate CSI-RS resource configuration and CSI report configuration to UE 1102. For example, through resource configuration, the base station may configure a plurality of CSI-RS resources in a CSI-RS resource set to UE 1102. The plurality of CSI-RS resources may correspond to one or more channel measurement resources (CMR) specified in the CSI report configuration. For example, a CSI report configuration may be associated with one or more resource configurations. The CSI report configuration may indicate a codebook type, such as a type I codebook type or a type II codebook type.

In step S1120, the base station can then trigger UE 1102 to perform a CSI measurement and reporting process (e.g., by sending an RRC message, a MAC CE command, or a DCI). TRP 1101 can then send a CSI-RS to UE 1102. In S1130, UE 1102 can receive the CSI-RS and perform channel measurement according to the CSI-RS configuration and the CSI reporting configuration. In S1140, based on the measurement results, UE 1102 can derive CSI, such as PMI, RI, CQI, etc. UE 1102 can report CSI to the base station.

At step S1150, the base station performs PDSCH transmission from TRP 1101 based on the reported PMI, RI, and CQI. At S1160, UE 1102 may receive the PDSCH and decode the data carried in the PDSCH. Process 1100 may end at step S1150.

IV. CSI-RS Resource Allocation

In some implementations, the network may configure the UE with a CSI-RS resource set. The CSI-RS resource set may include multiple CSI-RS resources. The CSI-RS resource set may be used for CSI measurement and reporting for mTRP CJT. The CSI-RS resource set may include multiple resource groups. Each resource group includes at least one CSI-RS resource. CSI-RS resources within the same resource group may mean that the CSI-RS resources may be sent from the same co-located TRP, panel, or multiple TRPs. The UE may assume that CSI-RS resources belonging to the same resource group may be transmitted under the same quasi co-location (Quasi Co Location, QCL) assumption. In some implementations, the network may configure and trigger the UE with a CSI report configuration. The CSI report configuration may associate the CSI-RS resource set with at least one channel measurement selection information. The channel measurement selection information may indicate which CSI-RS resources in a CSI-RS resource set should be measured together. The UE may measure a plurality of resources or a plurality of resource groups based on at least one channel measurement selection information to estimate CSI information for CSI reporting.

In some implementations, in order to mix mTRP CJT CSI and sTRP CSI in the CSI report, the UE may be configured with a plurality of channel measurement selection information to indicate which CSI resources should be estimated. Each channel measurement selection information may be associated with or represented by at least one CSI-RS resource indicator (CSI-RS Resource Indicator, CRI). In some examples, one CRI may indicate at least one CSI-RS resource belonging to a resource group. In some examples, one CRI may indicate at least two CSI-RS resources belonging to at least two resource groups used for mTRP CJT transmission. In some examples, one channel measurement selection information may indicate at least one CRI. The CRIs used for indexing sTRP CSI and mTRP CSI may be separated.

Figures 12A and 12B show examples of resource group configuration. In the CSI resource setting of Figure 12A, resource set #0 includes 4 RS resources RS#1 to RS#4. The 4 RS resources are divided into 3 resource groups 1 to 3. The first resource group includes RS#1 and RS#2. The second and third resource groups include RS#3 and RS#4, respectively.

FIG. 12B shows 4 TRPs (TRP 1 to TRP 4). TRP1 and TRP2 are co-located with each other. Therefore, for the purpose of CSI reporting, the signals from TRP1 and TRP2 can be considered as quasi-located (QCLed). TRP3 and TRP4 are located at different distances from the locations of TRP1 and TRP2. As shown, the 4 RS resources configured in FIG. 12A are respectively allocated to the 4 TRP1 to 4 in FIG. 12B. In particular, RS#1 and RS#2 in the same resource group 1 are allocated to the co-located TRP1 to 2. When reporting CSI (including in-phase/amplitude/power difference) based on resource groups, TRP1 and TRP2 can be considered as one unit. In this way, the signaling cost of CSI reporting can be reduced.

Example #0 - CSI-RS resource settings

Figures 13A and 13B show examples of CSI-RS resource configurations for mTRP CJT reporting only (without reporting for sTRP). For example, as shown in Figure 13A, the network (or base station) configures K=4 CSI-RS resources {RS#1, RS#2, RS#3, RS#4} in the CSI-RS resource set to the UE only for reporting mTRP CJT CSI. As shown in Figure 13B, a group of 4 TRPs {TRP1, TRP2, TRP3, TRP4} are geographically separated. Four CSI-RS resources {RS#1, RS#2, RS#3, RS#4} are sent from the four TRPs {TRP1, TRP2, TRP3, TRP4} respectively. In some examples, as shown in Figure 13A, the four CSI-RS resources can be grouped into four resource groups from resource group #1 to resource group #4. A resource group includes a CSI-RS resource. Each resource group corresponds to a geographically separated TRP. In some examples, when CSI-RS resources and resource groups are 1-to-1 mapped, resource groups can be omitted from the configuration.

Example #1 - CSI-RS Resource Setup

Figures 14A and 14B show examples of CSI-RS resource configuration for mTRP CJT reporting only (no reporting for sTRP). For example, as shown in Figure 14A, the network (or base station) configures K=4 CSI-RS resources {RS#1, RS#2, RS#3, RS#4} in the CSI-RS resource set to the UE only for reporting mTRP CJT CSI. As shown in Figure 14B, a set of 4 TRPs {TRP1, TRP2, TRP3, TRP4} are deployed. TRP1 and TRP2 are co-located. TRP3 and TRP4 are geographically separated. 4 CSI-RS resources {RS#1, RS#2, RS#3, RS#4} are sent from the 4 TRPs {TRP1, TRP2, TRP3, TRP4} respectively. The 4 CSI-RS resources are grouped into 3 resource groups from resource group #1 to resource group #3, as shown in Figure 14A. Resource group #1 includes CSI-RS resources RS#1 and RS#2. Resource groups #2 and #3 include CSI-RS resources RS#3 and RS#4, respectively. Grouping CSI-RS resources RS#1 and RS#2 into the same resource group #1 can implicitly indicate to the UE that {RS#1, RS#2} are co-located and have the same QCL (quasi-co-location) assumption.

Example #2 - CSI-RS Resource Setup

Figures 15A and 15B show examples of CSI-RS resource configuration for sTRP and mTRP CJT joint reporting, sTRP CSI reporting, or mTRP CSI reporting. For example, as shown in Figure 15A, the network (or base station) configures a CSI-RS resource set for the UE. The CSI-RS resource set may include K=4 CSI-RS resources {RS#1, RS#2, RS#3, RS#4}. As shown in Figure 15B, 4 CSI-RS resources may be allocated or sent from 4 TRPs {TRP1, TRP2, TRP3, TRP4}, respectively. As shown, the 4 TRPs {TRP1, TRP2, TRP3, TRP4} are geographically separated.

In addition, the CSI-RS resource set may include an indication of one or more CJT sets. In some examples, each CJT set may include one or more CSI-RS resources configured in the CSI-RS resource set. In some examples, each CJT set may include more than one CSI-RS resource configured in the CSI-RS resource set. In Figure 15A, the CSI-RS resource set is shown as including K _CJT = 2 CJT sets, CJT set #1 and CJT set #2. CJT set #1 includes CSI-RS resources from RS#1 to RS#4. CJT set #2 includes CSI-RS resources from RS#1 to RS#3. The CJT sets can be used for mTRP CJT CSI reporting. Different CJT sets may indicate different CJT transmission assumptions.

In addition, in the CSI-RS resource set shown in FIG. 15A, each CSI-RS resource and CSI-RS resource set can be associated with a CRI. In some examples, CRIs for sTRP and mTRP measurements may be provided separately or not separately. In the example of FIG. 15A, 4 CRIs {CRI#1, CRI#2, CRI#3, CRI#4} corresponding to 4 CSI-RSs {RS#1, RS#2, RS#3, RS#4} are provided for sTRP CSI resources. Two CRIs {CRI#1, CRI#2} corresponding to CJT set #1 and CJT set #2 are provided for mTRP CSI reporting, respectively. The UE may report CSI (PMI, RI, CQI, etc.) accompanied by CRI (e.g., in the form of CRI index).

V. Type II CSI Codebook Design for mTRP Transmission

1. Overall precoder structure of PMI in CSI report

在上面的算式中，n表示通道的子帶，並且n=0,1,...N ₃-1。P _CSI-RS 是UE處的CSI-RS埠的總數。v是傳輸秩。W ^T [n]是對應於PMI子帶n中的層r=1,...,v的P _CSI-RS ×1預編碼器，使得[W ^r [0] W ^r [1]…

W ^(p)[n]是第p個TRP的

×v預編碼器，p=1,...N _P 。

是第p個TRP的CSI-RS埠的數目。N _p 是為CJT配置的TRP的總數。 In some implementations, the overall mTRP CJT precoder reported by the first UE in the PMI may have size PCSI _{- RS} × v and take the form,

In the above equation, n represents the channel subband, and n = 0, 1, ... N ₃ -1. PCSI _{- RS} is the total number of CSI-RS ports at the UE. v is the transmission rank. WT [ n ] is the ^PCSI _{- RS} ×1 precoder corresponding to layer r = 1, ..., v in PMI subband n , such that [ Wr [ ⁰ ] Wr [1 ^] ...

W ^(p) [ n ] is the pth TRP

× v precoder, p =1,... N _P .

is the number of CSI-RS ports of the pth TRP. Np is the total _number of TRPs configured for CJT.

W ₁ 指示層共同空間域資訊(例如，SD基向量)。例如，不同的層可以共用相同的SD基向量矩陣 W ₁ 。 W ₂ 展示層特定線性組合係數(例如，FD係數)。 W _f 展示層特定頻率域資訊(例如，FD基向量)。 For ease of representation, the superscripts of each matrix are omitted in the following description. The overall mTRP CJT precoder can be expressed as follows:

W ₁ indicates layer common spatial domain information (e.g., SD basis vectors). For example, different layers can share the same SD basis vector matrix W ₁ . W ₂ shows layer specific linear combination coefficients (e.g., FD coefficients). W _f shows layer specific frequency domain information (e.g., FD basis vectors).

2. W ₁ Matrix design

其中，N _P 是相干發送TRP的數目。

可以是

×2L _p SD基矩陣並且表示第p個TRP的SD基向量。例如，

具有以下形式

是TRP中tx埠的數目，p=1,...N _P ，並且L _p 是TRP的每個極化中的SD基向量的數目，p=1,...N _P ，使得

並且

。 In some implementations, W ₁ represents the spatial domain (SD) DFT basis vectors, which are reported jointly across the wideband and layer. The SD basis matrix W ₁ for mTRP CJT can take the following form:

_Where NP is the number of coherently transmitted TRPs.

Can be

×2 L _p SD basis matrix and represents the SD basis vector of the p -th TRP. For example,

Has the following form

is the number of tx ports in the TRP, p =1,... N _P , and L _p is the number of SD basis vectors in each polarization of the TRP, p =1,... N _P , such that

And

.

。當每個TRP在mTRP傳輸中配置有CSI-RS資源時，每個CSI-RS資源對應於特定的

。換言之，SD基選擇是逐個CSI-RS資源的。並且，

可以包括極化共同的SD基。例如，基向量 v ₁ ,…,

是在兩個極化之間共用的。因此，對於給定的CSI-RS資源，SD基選擇可以是極化共同的。如 W ₁ 指示層共同空間域的資訊，對於給定的CSI-RS資源，SD基選擇可以也是層共同的。 It can be seen that _the SD basis matrix W1 used for mTRP CJT can have a block diagonal structure. The block diagonal structure _of W1 implies a TRP-specific SD basis choice. For example, different TRPs can correspond to different

When each TRP is configured with CSI-RS resources in mTRP transmission, each CSI-RS resource corresponds to a specific

In other words, SD-based selection is done on a CSI-RS resource-by-CSI-RS resource basis. And,

A polarized common SD basis can be included. For example, the basis vectors v ₁ ,…,

is shared between the two polarizations. Therefore, for a given CSI-RS resource, the SD basis selection can be polarization-common. As W ₁ indicates information of the layer-common spatial domain, for a given CSI-RS resource, the SD basis selection can also be layer-common.

≠

。第三，相對於特定UE，針對不同TRP的視線(line-of-sight，LOS)或非視線(non-line-of-sight，NLOS)條件可以是不同的。在這種情況下，可以預期跨TRP，SD基向量的數目是不同的，即對於p≠q，L _p ≠L _q 。例如，{ L _p ,p=1,...N _P }可以是由基地台配置的高層。或者，針對所有TRP的 L _p 的總數可以由基地台配置。UE可以報告{ L _p ,p=1,...N _P }。 The design principle of W1 is as follows. First, _W1 has a block diagonal structure. Tx ports across different TRPs act as isolated spatial paths that can be used for diversity/multiplexing. Second, geographically separated _TRPs mean that the SD basis vectors for the TRPs are different, i.e., for p ≠ q ,

≠

. Third, with respect to a particular UE, the line-of-sight (LOS) or non-line-of-sight (NLOS) conditions for different TRPs can be different. In this case, it can be expected that the number of SD basis vectors is different across TRPs, i.e., for p ≠ q , L _p ≠ L _q . For example, { L _p , p =1,... N _P } can be a high-level configuration by the base station. Alternatively, the total number of L _p for all TRPs can be configured by the base station. The UE can report { L _p , p =1,... N _P }.

A.W. ₁ Feedback reduction

If the pth TRP is co-located with the qth TRP, the co-located TRPs can use the same SD basis vector, i.e., W1 ^{( p )} = W1 ^{( q )} . Therefore, using this knowledge can reduce UE calculation/feedback overhead. In various implementations _, the following two methods can _be used to reduce W1 _feedback :

Alternative 1: The base station (e.g., gNB) uses high-layer signaling, such as RRC or MAC-CE, to inform the UE about the co-located TRP.

Alternative 2: Based on the calculated W ₁ ^{( p )} , the UE may determine to report only W ₁ ^{( p )} with different SD information.

Example #3 - W ₁ Feedback reduction (alternative 1.1)

用於CSI報告。在這樣的配置下，可以配置天線配置(N ₁ ，N ₂ )和(O ₁ ，O ₂ )用於每個CSI-RS資源(另選方案1.1)。 In some examples, if some TRPs are co-located, the network (NW) can notify the UE of the co-location relationship between the TRPs. In various implementations, there are multiple ways to notify the UE of the co-location information. For example, the network can configure the CSI-RS resources of the co-located TRPs in the same resource group. The CSI reports associated with the CSI-RS resources in the same resource group can share _the same W1 information. For example, corresponding to the co-located TRPs or CSI-RS resources in the same resource group, a

For CSI reporting. In such _a configuration, antenna configurations ( N1 , N2 ) and ( O1 _, O2 ) can be _configured for _each CSI-RS resource (Alternative 1.1).

Figure 16 shows a first example of W1 feedback reduction. As shown, 4 TRPs from _TRP1 to TRP4 are deployed. Each TRP has a configuration of ( N1 , N2 ) = (4 _{, 1} ) and 8 CSI-RS ports. A total of 4 TRPs have PCSI _{- RS} = 32 CSI-RS ports. The four CSI-RS resources from RS#1 to RS#4 are configured by 4 TRPs respectively.

,

,

,

}可 以是不同的。可以在分別與4個CSI-RS資源{RS#1，RS#2，RS#3，RS#4}對應的CSI報告中報告4個SD基矩陣{

,

,

,

}。 FIG. 16 lists four scenarios 1601-1604 of TRP co-location configuration. In scenario 1601, the four TRPs are non-co-located. The network can signal the resource group configuration to the first UE as follows: {Resource group #1 (RS#1), resource group #2 (RS#2), resource group #3 (RS#3), resource group #4 (RS#4)}. For each of the four SD basis matrices of the TRP {

,

,

,

} may be different. Four SD base matrices {RS#1, RS#2, RS#3, RS#4} may be reported in the CSI report corresponding to the four CSI-RS resources {RS#1, RS#2, RS#3, RS#4}, respectively.

,

,

,

}.

,

,

,

}。TRP1和TRP2的SD基矩陣可以相似或相同。因此，可以在與4個CSI-RS資源{RS#1，RS#2，RS#3，RS#4}對應的CSI報告中報告3個SD基矩陣{

,

,

}。 In scenario 1602, TRP {TRP1, TRP2} are co-located, and TRP {(TRP1/TRP2), TRP3, TRP4} are non-co-located. The network may signal the resource group configuration to the first UE as follows: {resource group #1 (RS#1, RS#2), resource group #2 (RS#3), resource group #3 (RS#4)}. The four SD base matrices may be {

,

,

,

}. The SD base matrices of TRP1 and TRP2 may be similar or identical. Therefore, three SD base matrices {RS#1, RS#2, RS#3, RS#4} may be reported in the CSI report corresponding to four CSI-RS resources {RS#1, RS#2, RS#3, RS#4}.

,

,

}.

,

,

,

}。TRP2和TRP3的SD基矩陣可以相似或相同。因此，可以在與4個CSI-RS資源{RS#1，RS#2，RS#3，RS#4}對應的CSI報告中報告3個SD基矩陣{

,

,

}。 In scenario 1603, TRPs {TRP2, TRP3} are co-located and TRPs {TRP1, (TRP2/TRP3), TRP4} are located at different locations. The network may signal the resource group configuration to the first UE as follows: {resource group #1 (RS#1), resource group #2 (RS#2, RS#3), resource group #3 (RS#4)}. The four SD base matrices may be {

,

,

,

}. The SD base matrices of TRP2 and TRP3 may be similar or identical. Therefore, three SD base matrices {RS#1, RS#2, RS#3, RS#4} may be reported in the CSI report corresponding to four CSI-RS resources {RS#1, RS#2, RS#3, RS#4}.

,

,

}.

,

,

,

}。TRP1和TRP2的SD基矩陣可以相似或相同。TRP3和TRP4的SD基矩陣可以相似或相同。因此，可以在與4個CSI-RS資源{RS#1，RS#2，RS#3，RS#4}對應的CSI報告中報告2個SD基矩陣{

,

}。 In scene 1604, TRP {TRP1, TRP2} are co-localized. TRP {TRP3, TRP4} are also co-localized. TRP {(TRP1/TRP2), (TRP3/TRP4)} are non-co-localized. The 4 SD basis matrices can be {

,

,

,

}. The SD base matrices of TRP1 and TRP2 may be similar or identical. The SD base matrices of TRP3 and TRP4 may be similar or identical. Therefore, two SD base matrices {RS#1, RS#2, RS#3, RS#4} may be reported in the CSI report corresponding to four CSI-RS resources {RS#1, RS#2, RS#3, RS#4}.

,

}.

Example #4 - W ₁ Feedback reduction (alternative 1.2)

可以在CSI報告中共用同一SD基矩陣，以減少CSI反饋開銷。 Figure 17 shows a second example of W ₁ feedback reduction. Similar to the example of Figure 17, 4 TRPs from TRP1 to TRP4 are deployed. The 4 TRPs have a total of PCSI _{- RS} = 32 CSI-RS ports. 4 CSI-RS resources from RS#1 to RS#4 are configured from the 4 TRPs respectively. 4 scenarios 1701-1704 are listed regarding the TRP co-location configuration listed in Figure 17. Scenarios 1701-1704 are similar to scenarios 1601-1604. Therefore, a CSI-RS resource grouping scheme can be similarly adopted to notify the UE of the TRP co-location configuration (or deployment). SD basis matrix corresponding to the CSI-RS resources configured for multiple co-located TRPs

The same SD base matrix can be shared in CSI reports to reduce CSI feedback overhead.

Unlike the example of FIG. 16 , the combined antenna configuration ( N ₁ , N ₂ ) is configured for CSI-RS resources corresponding to co-located TRPs (alternative 1.2). In some examples, the CSI-RS resources corresponding to co-located TRPs are divided into the same resource group. For example, in scenario 1702 , TRP1 and TRP2 are co-located. Therefore, a combined antenna configuration (8, 1) is configured for CSI-RS resources RS#1 and RS#2 corresponding to co-located TRP1 and TRP2. Similarly, in scenario 1704, a combined antenna configuration (8, 1) is configured for CSI-RS resources RS#1 and RS#2 corresponding to co-located TRP1 and TRP2, while another combined antenna configuration (8, 1) is configured for CSI-RS resources RS#3 and RS#4 corresponding to co-located TRP3 and TRP4.

Example #5 - W ₁ Feedback reduction (alternative 2.1)

In some examples, depending on W ₁ ^{( p )} calculated based on CSI-RS measurement results, the UE may report only a set of W ₁ ^{( p )} with different SD basis vector information. For example, for W ₁ ⁽¹⁾ and W ₁ ⁽²⁾ corresponding to two co-located TRPs, report one SD basis vector matrix W ₁ ⁽¹⁾ or W ₁ ⁽²⁾ instead of reporting both.

,

,

,

}。例如，

包含SD基的旋轉因數(i _1,1)和SD基指示符(i _1,2)：-->對於第p個TRP，

，其中，

並且

， -->對於第p個TRP，

FIG. 18 shows an example of reporting _the compressed SD basis vector matrix W1 . The PMI reporting format of _the W1 matrix can be TRP-specific, such as {

,

,

,

}.For example,

Contains the rotation factor of the SD basis ( i _1,1 ) and the SD basis indicator ( i _1,2 ): --> For the pth TRP,

,in,

And

, -->For the pth TRP,

，如第18圖所示，UE可以進一步壓縮 W ₁ 。在一個示例中，UE可以報告

和

，每個僅具有3個元素而不是4個元素，如第18圖所示。在一個示例中，UE可以進一步報告附加的四重索引，例如i _1,3={1,1,2,3}，以指示四個TRP的相應元素索引。具有相同值的索引可以指示共用相同SD基向量矩陣的相應複數個W ₁ ^(p)。 Considering the 4-TRP CJT CSI report, if the SD matrices calculated for TRP1 and TRP2 are the same, i.e.

, as shown in FIG. 18 , the UE may further compress W ₁ . In one example, the UE may report

and

, each with only 3 elements instead of 4 elements, as shown in Figure 18. In one example, the UE may further report an additional quadruple index, such as i _1,3 ={1,1,2,3}, to indicate the corresponding element indices of the four TRPs. Indices with the same value may indicate corresponding plural W ₁ ^{( p )} sharing the same SD basis vector matrix.

Example #6 - W ₁ Feedback reduction (alternative 2.2): W for dynamic sTRP and mTRP switching ₁ PMI Sharing

FIG. 19A shows the switching of sTRP and mTRP. As shown, four TRPs from TRP1 to TRP4 are deployed around UE 1901. Initially, UE 1901 communicates with a single TRP (TRP4). UE 1901 moves away from TRP4 toward TRP1, TRP2, and TRP3. Based on the CSI report from UE 1901, the base station (not shown) can control UE 1901 and the four TRPs to switch from the previous sTRP transmission to mTRP transmission. In the scheme of FIG. 19A, CSI about the channels between UE 1901 and the four TRPs can be reported to the base station to support dynamic sTRP and mTRP switching.

{0,1,2,3,4}。在該另選場景中，可以從基地台向UE 1901分別配置用於CJT和單個TRP測量的單獨的CRI索引。基於CSI-RS測量，可以得出和報告與相應CRI對應的單獨的CSI。 To support dynamic switching between sTRP and mTRP transmissions, UE 1901 may report one CSI for CJT and sTRP. For example, UE 1901 may report one CSI reflecting the channel conditions between UE 1901 and four TRPs. Alternatively, UE 1901 may report one CSI for CJT and X CSIs for a single TRP transmission. For example, X

{0,1,2,3,4}. In this alternative scenario, separate CRI indices for CJT and single TRP measurement can be configured from the base station to UE 1901, respectively. Based on the CSI-RS measurement, a separate CSI corresponding to the corresponding CRI can be derived and reported.

,

,

,

}和

,

,

,

)和CQI。然而，從mTRP CSI中省略了SD基矩陣 W ₁ 。基地台在接收到包含在4個sTRP CSI中的

、

、

、

之後，可以相應地得出 W ₁ SD基矩陣。 In the above alternative, _the W1 matrix can be shared between sTRP and mTRP CSI reporting. For example, only one W1 matrix corresponding to each TRP is reported. Figure 19B shows another example of _W1 feedback reduction in the scenario of mixed sTRP and mTRP CSI reporting of Figure 19A. As shown, one sTRP CSI corresponding to each TRP is reported, including CRI, RI, PMI ( W1 , W2 _, Wf ₎ and CQI. Corresponding to 4 TRPs, _one mTRP CSI is reported _. The mTRP CSI may include CRI, RI, PMI ({

,

,

,

}and

,

,

,

) and CQI. However, the SD matrix W ₁ is omitted from the mTRP CSI. The base station receives the SD matrix W 1 included in the 4 sTRP CSI.

,

,

,

Afterwards, the W ₁ SD basis matrix can be obtained accordingly.

3. W ₂ Matrix design

其中， W ₁ 表示寬頻SD基向量的矩陣， W ₂ 表示將SD基向量線性組合的空間頻率壓縮係數的矩陣，並且 W _f 表示用於FD壓縮的DFT基向量。如所示出的， W ₁ 具有的尺寸為

。 W ₂ 具有的尺寸為

，其中N ₃是mTRP傳輸的通道的子帶數目。 W _f 具有的尺寸為N ₃×N ₃。從 W _f 中選擇M個FD基向量。相應地，在第20圖的示例中， W ₂ 中包括M列頻率係數。 FIG. 20 shows a type II codebook precoder structure 2000 for mTRP CJT feedback. The precoder structure 2000 may correspond to the precoder described above,

Where W1 represents the matrix of broadband SD basis vectors, W2 represents the matrix of spatial frequency compression coefficients _that linearly combine _the SD basis vectors, and Wf _represents the DFT basis vectors used for FD compression. As shown _, W1 has a size of

. W ₂ has the dimensions

, where N ₃ is the number of subbands of the channel transmitted by mTRP. W _f has a size of N ₃ × N ₃ . M FD basis vectors are selected from W _f . Accordingly, in the example of FIG. 20 , W ₂ includes M columns of frequency coefficients.

Among the M columns of coefficients, the most significant coefficient 2001 may be selected and quantized. After quantization, a set of NZCs may be reported in the corresponding SCI. For example, the selected linear combination coefficients of W2 may be reported to the _gNB in the form of the single strongest coefficient in a particular polarization, reference amplitudes for other polarizations, polarization-specific differential amplitude and phase coefficients.

In some examples, _the W2 coefficients may be reported as a set of coefficient indicators in the CSI report. For example, the coefficient indicators may be categorized as:

-SCI (Strongest coefficient indicator): i _1,8

-ACI (Amplitude coefficient indicator)

○Reference range: i _2,3

○Differential amplitude: i _2,4 (relative to SCI or ACI)

-PCI (Phase coefficient indicator): i _2,5

-NZC bitmap: i _1,7 (indicates the coefficient position in W ₂ )

In some examples, _the W2 design can follow the following principles:

- NZCs can be selected _across TRPs. For example, W2 coefficients corresponding to different TRPs can be considered together for selecting or determining which coefficients to report.

來確定逐層NZC的最大數目，其中β是NZC選擇比。 o Based on

to determine the maximum number of layer-by-layer NZCs, where β is the NZC selection ratio.

-One strongest coefficient (SCI) across all TRPs - Magnitude and phase are not reported for SCI.

-The reference amplitude indicator can be

o TRP common, i.e. one reference amplitude across all TRPs

o TRP specific, i.e. each TRP has a reference amplitude

o Polarization common, i.e. one reference amplitude for both polarizations

o Polarization specific, i.e. each polarization has a reference amplitude

o The reference amplitude can be quantized to e.g. 4 bits

- All other NZCs are quantized relative to the corresponding reference amplitude, e.g. using 3 bits (i.e. differential amplitude).

- All NZC phases can be quantized to e.g. 16 PSK instead of SCI.

-NZC bitmaps can be TRP common or TRP specific

2L _p )×M o TRP common: total bitmap size is (

2 L _p )× M

2L _p M _p ， 其中 o TRP specific: Total bitmap size is

2 L _p M _p , where

是所選/服務TRP集 ￭

Is the selected/service TRP set

是所選擇的TRP的數目，即，

￭

is the number of TRPs chosen, i.e.,

￭ L _p is the beam number of the pth TRP

￭ M _p is the number of selected FD bases of the pth TRP

￭ M is the number of common FD bases of TRP.

和

分別是極化0和1的第p個TRP的參考幅度。 FIG. 21 shows an example of NZC selection according to an embodiment of the present invention. In the example of FIG. 21,

and

are the reference amplitudes of the pth TRP for polarizations 0 and 1, respectively.

Example #7 - NZC Selection

2L _p 區域中的矩陣元素的佈局。如所示出的，確定與係數2201對應的TRP共同的SCI。確定與係數2202對應的TRP共同的參考幅度。 Figures 22A to 22B illustrate examples of NZC selection for mTRP CSI reporting according to an embodiment of the present invention. There are 4 TRPs in the CSI report. Each TRP has two antenna polarizations. For each polarization, 2 SD basis vectors are reported ( Lp = 2). M = 3 FD basis vectors are selected for the 4 TRPs. Figure 22A illustrates different types _of indicators and corresponding selection methods (TRP common or TRP specific) for reporting W2 coefficients. Figure 22B illustrates the M× in _the linear combination coefficient matrix W2 _.

2 L _p region. As shown, determine the common SCI of the TRPs corresponding to coefficient 2201. Determine the common reference amplitude of the TRPs corresponding to coefficient 2202.

To determine the differential amplitudes of other NZCs, TRP-specific NZCs (e.g., coefficients 2203-2204) may be selected. Each differential amplitude of these TRP-specific selected NZCs may be determined relative to a corresponding reference amplitude depending on which polarization the selected NZC belongs to. For example, matrix elements (or coefficients) 2203 and 2204 belong to the first antenna polarization and the second antenna polarization, respectively. Thus, the reference amplitudes of elements 2202 and 2201 are used to determine the differential amplitudes of elements 2203 and 2204, respectively. The differential amplitudes of the TRP-specific selected NZCs may be quantized prior to CSI reporting.

Example #8 - NZC Selection

2L _p 區域中的矩陣元素的佈局。類似地，確定與係數2305對應的TRP共同的SCI。 Figures 23A to 23B illustrate another example of NZC selection for mTRP CSI reporting according to an embodiment of the present invention. Similarly, there are 4 TRPs in the CSI report. Each TRP has two polarizations. Corresponding to each polarization, 2 SD basis vectors are reported ( Lp = 2). M = 3 FD basis vectors are selected for the ₄ TRPs. Figure 23A illustrates different types _of indicators and corresponding selection methods (TRP common or TRP specific) for reporting W2 coefficients. Figure 23B illustrates _the M×

2 L _p region. Similarly, determine the SCI common to the TRP corresponding to coefficient 2305.

Unlike the example of FIGS. 22A to 22B, a plurality of reference amplitudes are selected in a TRP-specific and polarization-specific manner. For example, two selected reference amplitudes correspond to coefficients (or matrix elements) 2301 and 2302 having different polarizations and belonging to the same TRP 1. Two selected reference amplitudes correspond to coefficients (or matrix elements) 2303 and 2304 having different polarizations and belonging to the same TRP 2. Thus, in order to determine the differential amplitude of other NZCs, the TRP-specific selected NZCs can be compared with the corresponding TRP-specific and polarization-specific reference amplitudes.

4. W _f Matrix design

矩陣 W _f 表示用於頻率域壓縮的頻域(frequency domain，FD)基向量。在各種實施方式中，FD基選擇設計可以遵循以下原理(另選方案1和另選方案2)。FD壓縮可以有兩種選擇。 As mentioned above, the overall mTRP CJT precoder can be expressed as follows:

_The matrix Wf represents the frequency domain (FD) basis vectors used for frequency domain compression. In various implementations, the FD basis selection design can follow the following principles (Alternative 1 and Alternative 2). There are two options for FD compression.

，使得

並且

。主要原理是考慮由於相應TRP之間的時間偏移而導致的在TRP上的子帶相位跳變。在一些示例中，TRP特定的FD基向量選擇方法可應用於mTRP傳輸，其中所部署的TRP包括共定位的TRP。 Alternative 1 : TRP-independent (or TRP-specific) FD basis selection. M _p FD basis vectors p = 1, ... N _P can be selected for the p-th TRP. The overall frequency domain basis vector set can be

, so that

And

The main principle is to consider the sub-band phase jumps on TRPs due to the time offset between corresponding TRPs. In some examples, the TRP-specific FD basis vector selection method can be applied to mTRP transmission, where the deployed TRPs include co-located TRPs.

[00136] Alternative 2 : TRP common (or joint) FD basis selection. M FD basis vectors may be selected across TRPs (for all TRPs). In some examples, the cross-TRP (or TRP common) FD basis vector selection method may be applied to mTRP transmissions, where the deployed TRPs include geographically distributed TRPs.

)包括逐個TRP的係數矩陣{

,

,...,

}。對於另選方案1 的SD基矩陣 W _f (

)，逐個TRP選擇SD基向量。例如，為TRP⁽¹⁾選擇M₁個SD基向量。為TRP⁽²⁾選擇M₂個SD基向量。為TRP^(Np)選擇M_Np個SD基向量。對於另選方案2的SD基矩陣 W _f (

)，跨TRP選擇SD基向量。 FIG. 24 shows examples of FD basis vector selection alternatives according to an embodiment of the present invention. Two alternatives are shown: Alternative 1, TRP-independent FD basis selection, and Alternative 2, TRP-common FD basis selection. As shown, the coefficient matrix W ₂ (

) includes the coefficient matrix for each TRP {

,

,...,

}. For the SD basis matrix W _f of alternative 1 (

), select SD basis vectors for each TRP. For example, select M ₁ SD basis vectors for TRP ⁽¹⁾ . Select M ₂ SD basis vectors for TRP ⁽²⁾ . Select M _Np SD basis vectors for TRP ^(Np) . For the SD basis matrix W _f (

), select SD basis vectors across TRP.

Corresponding to the two FD basis selection alternatives 1 and 2, the overall mTRP CJT precoder can take the following two forms:

Alternative 1:

如所示出的，對於跨N_p個TRP(另選方案1)的獨立FD基選擇，逐個TRP FD基向量矩陣{

,...,

}對於不同的TRP是不同的。對於TRP共同的FD基選擇，不同的TRP共用相同的FD基向量矩陣

。 Alternative 2:

As shown, for independent FD basis selection across _Np TRPs (Alternative 1), the TRP-by-TRP FD basis vector matrix {

,...,

} is different for different TRPs. For the common FD basis choice of TRPs, different TRPs share the same FD basis vector matrix

.

Example #9 - W _f FD basis selection

{-2M+1,-2M+2,...,0} In some examples, the FD basis indicators ( i _1,5 and i _1,6 ) for the W _f matrix in the CSI report include an initial window position M _initial (eg, for N ₃ >19) and an FD basis index n ₃ , where i _1,5 : M _initial

{-2M+1,-2M+2,...,0}

{0,1,...,N₃-1} i _1,6 ：n ₃ =[n _3,0 ,...,n _3,M-1 ] and n _3,f

{0,1,...,N ₃ -1}

Corresponding to the above SD basis selection alternatives, the PMI report format of FD basis vectors can have two designs:

-Alternative 1: Report FD-based indicators for each TRP (TRP-specific).

,

,

,

}和i _1,6：{

,

,

,

}。 Considering the 4 TRP cases, the report format can be i _1,5 : {

,

,

,

} and i _1,6 : {

,

,

,

}.

-Alternative 2: Report FD-based indicators across all TRPs (TRP-common)

The report formats can be i _1,5 : { M _initial } and i _1,6 : { n ₃ }

和

。另選方案2情況對應於FD基向量另選方案2的PMI報告格式。不同的TRP具有相同的指示符M _initial 和n _3,l 。 FIG. 25 shows an example of the initial window position and FD basis index in _the FD coefficient matrix W2 . As shown, the Alternative 1 case corresponds to the PMI reporting format of the FD basis vector Alternative 1. Different TRPs have different indicators

and

. Alternative 2 case corresponds to the PMI reporting format of FD basis vector alternative 2. Different TRPs have the same indicators M _initial and n _{3, l} .

VI. Dynamic TRP Selection

For example, due to UE motion and blocking, a UE may need to measure multiple sets of CSI-RS resources from multiple TRPs for mTRP measurements and CJT/NCJT transmissions. In some cases, a UE may be served by at least two dominant TRPs (larger received power comes from at least two dominant TRPs). Non-dominant TRPs may be turned off or used for other UEs. Flexible designs for network and UE selection of appropriate TRPs for mTRP measurements and transmissions are described here.

Figure 26 shows an example where different mTRP sets can be switched to serve a UE due to the UE's actions. As shown, UE1 is initially served by 4 TRPs from TRP1 to TRP4, and then by 3 TRPs from TRP1 to TRP3. UE2 is initially served by 3 TRPs from TRP2 to TRP4, and then by 1 TRP4.

In one example, the UE may perform measurements such as RSRP and RSRQ on a set of measurement objects {TRP1, TRP2, TRP3, TRP4, TRP5, TRP6, TRP 7, TRP8}. The network may determine one or more mTRP measurement sets for the UE based on the measurement results reported from the UE. The network may have a CSI report configuration with multiple CSI-RS resources and one or more CRIs to be configured by the UE to perform CSI measurements and reporting. For example, multiple CSI-RS resources may be sent from multiple TRPs of an mTRP measurement set. One or more CRIs may be associated with one or more mTRP measurement sets. For example, the measurement set associated with the CRI used for CSI measurement and estimation may be one or more of {TRP1, TRP2, TRP3}, {TRP1, TRP2}, {TRP2, TRP3}, {TRP1, TRP3}, {TRP1}, {TRP2}, or {TRP3}.

Based on the CSI report configuration, the UE can estimate the CSI report and feed it back to the network. The UE can indicate in the CSI report which CRI is better or which TRP may not be needed (which TRP may be more important). The network can select TRP for the UE to send PDSCH, PDCCH, etc. based on the CSI report. For example, the set selected for mTRP transmission based on the CSI report can be {TRP1, TRP2, TRP3}. Alternatively, the UE can perform the selection and report the selection result to the base station.

變體2：

Based on the type II codebook structure described herein, in some implementations, a TRP selection matrix W ₀ is introduced for CSI feedback from the UE to the network. FIG. 27 shows two types (two variants) of codebook structures for CSI feedback. The two types of codebook structures are based on the type II codebook structure and the TRP selection matrix W ₀ . The two types of codebook structures may take the following forms: Variant 1:

Variant 2:

The example shown in FIG. 27 corresponds to a scenario where there are 4 candidate TRPs on the network side and each TRP has N _Tp antenna ports. In the CSI reporting process, the UE can measure the CSI-RS from the 4 TRPs. Based on the measurement results, the UE can provide a CSI report to the network. The CSI report can indicate the selected TRP and the associated precoder. For example, the CSI report can include information about the matrices W ₀ , W ₁ , W ₂ and/or W _f shown in FIG. 27 .

W ₀ is the TRP/port/beam selection matrix. W ₀ can be used to dynamically report the CSI of a specific TRP/port. As shown in Figure 27, the TRP selection matrix may include a plurality of sub-matrices. Each sub-matrix has a size of N _Tp by N _Tp (or 2L _p ×2L _p ). Each sub-matrix corresponds to one of the four candidate TRPs, respectively. For an unselected TRP (e.g., the second of the four TRPs), the corresponding sub-matrix may be a zero matrix (each element is zero). For a selected TRP (e.g., the first TRP, the third TRP, or the fourth TRP), the corresponding sub-matrix may be a unit matrix.

For variant 1, feedback overhead can be reduced. Through this variant, the network may not know the SD information of the unselected TRP. For variant 2, the SD information of _all TRPs in the coordination set can be reported in W1 . The network can use the unselected TRP to serve another UE, or the _network can use the SD information of the unselected TRP to reduce inter-TRP interference. In addition, for variant 2, W1 can be reported in a broadband manner, and W0 can be reported in _a subband manner based on the subband precoder coefficient. In some examples, the network can use RRC, MAC CE, or DCI signaling to configure whether to use the selection matrix W0 . In some examples, the TRP/port selection criteria can be based on TRP power efficiency, channel correlation or capacity, interference reduction _, etc.

Example #10 - Dynamic TRP Selection

}, 其中，N _p 是網路所配置的候選TRP或TRP的數目，N' _p 是UE所選擇的服務TRP的 數目，並且

是在給定N _p 和N' _p 的情況下不同W₀的可能性的總數(從N _p 個候選TRP中選擇N' _p 個TRP的組合)。在一個示例中，N _p 和N' _p 的值可以從網路發訊號通知UE。在一些示例中，可以基於網路容量、要服務的UE的數目、UE能力、UE請求等的考慮來依據網路和UE之間的協商來確定N _p 和N' _p 的值。 In an example, when the network uses RRS signaling to configure the UE to report the TRP matrix W ₀ , the UE may report a TRP selection indicator i ₀ representing the TRP selection matrix W _0. For example, the TRP selection indicator i ₀ may have integer values arranged as follows {0, 1, 2, ...

}, _where Np is the number of candidate TRPs or TRPs configured by the network, N'p is the number of serving TRPs selected _by the UE, and

is the total number of different _W0 possibilities given Np and N'p (selecting _a combination of _{N'p TRPs} from Np candidate TRPs). In one example, the values _of Np and _N'p may be signaled to the UE from the network. In some examples, the values of Np and N'p _{may be} determined based on negotiation between the network and _the UE based on considerations of network capacity, the number of UEs to be served, UE capabilities, UE requests, etc.

In some examples, W ₀ can be mapped to CRI feedback. In the case where a single TRP is used for transmission, the UE typically selects a CRI to feedback the best BS beam or selects a TRP from candidate TRPs for RI/PMI/CQI feedback. In the case of mTRP joint transmission (JT), the UE can select and report multiple CRIs mapped to multiple TRPs for NCJT/CJTRI/PMI/CQI feedback. There is a mapping relationship between the TRP selection matrix W ₀ and the selection of CRI (e.g., represented by a bitmap).

For the reporting of W ₁ , in an example, when the structure W = W ₀ W ₁ W ₂ W _f is used, the UE can avoid feeding back the W ₁ information of the unselected TRP. As shown in the variant 1 structure in Figure 27, the sub-matrix corresponding to the second TRP (TRP2) is not reported in the CSI report because the second TRP is not selected. In this way, signaling costs can be saved. When the structure W = W ₁ W ₀ W ₂ W _f is used, the UE can still feed back the W ₁ information of the unselected TRP.

For reporting of W ₂ and W _f , the UE may avoid reporting information of unselected TRPs to save feedback overhead. For example, one or more indicators are predefined or configured for reporting information carried in W ₂ and W _f . For unselected TRPs, the corresponding indicators corresponding to the unselected TRPs may be removed from the report.

VII.CSI Report Configuration

In some implementations, the CSI report configuration may be configured via high-layer (above the physical layer) signaling (e.g., MAC CE and RRC). The CSI report configuration may include one or more codebook configurations. A codebook configuration may include one or more antenna configurations ( N1 _, N2 ) for precoder estimation and selection. For example, an antenna configuration ( _{N1 ,} N2 ) may correspond to a CSI-RS resource or resource group. Figure 28A shows an example of a CSI report configuration. The _CSI report configuration includes a codebook configuration. Figure 28B shows an example of a codebook configuration. The codebook configuration includes codebook subset restriction information. The subset restriction information includes a set of antenna configurations ( N1 , N2 ). Each antenna configuration ( _{N1 , N2} ) corresponds to a _CSI -RS resource or a CSI-RS resource group.

In some examples, the CSI-RS resource set configured to the UE includes a plurality of resource groups. The UE may be configured with one or more codebook configurations for precoder estimation and selection on a plurality of resource groups. A codebook configuration may include one or more values of ( N1 , N2 ). Each value of ( N1 , _N2 ) may correspond to a resource group. As shown _in the example of FIG. 17, for the case of 1702, { _TRP1 , TRP2 } are co-located. CSI-RS {RS#1, RS#2} are included in resource group 1. Therefore, an antenna configuration ₍ 8, 1) is provided for TRP1 and TRP2 together. Similarly, in the case of 1703, an antenna configuration (8, 1) is provided for resource group 2. In the case of 1704, two antenna configurations (8, 1) and (8, 1) are provided for resource groups 1 and 2, respectively.

In some implementations, the CSI report configuration may include at least one power indicator to indicate how to adjust at least the transmit power of at least one resource group belonging to the CRI or which TRPs share the same total power. For example, if the resource set includes only one resource or one resource group for a single TRP transmission, the precoder power is typically normalized to 1 and no power indicator is required. In other examples, at least one power indicator may be provided for mTRP CJT transmissions, since different TRPs may use different transmit powers and some TRPs may share the same power source or the same total power. The UE may use at least one power indicator to estimate PMI and CQI for CSI reporting.

Example #11 - Power Indicator

In some examples, based on at least one power indicator, the UE can understand which of the following power adjustment methods or modes is used for TRP transmission.

其中

並且v是傳輸秩並且p

是相干服務TRP的集。

是TRP功率調節預編碼器。 W ^{( p )}是UE報告的CJT預編碼器。 Method 1: Each TRP in the selected TRP set transmits at full power, i.e., the precoder used by the pth TRP is

in

and v is the transmission rank and p

Is a set of related service TRPs.

is the TRP power regulation precoder. W ^{( p )} is the CJT precoder reported by the UE.

個TRP，以全功率發送。由第

個TRP使用的預編碼器可以是

其中c=max{c ₁,c ₂,c ₃,c ₄}並且

。 Method 2: At least one TRP in the selected TRP set, such as

TRP, sent at full power.

The precoder used by each TRP can be

where c = max{ c ₁ , c ₂ , c ₃ , c ₄ } and

.

The network can configure the UE to use which method through RRC or MAC CE signaling.

Example #12 - Power Indicator

是第p個TRP的預編碼器歸一化因數，並且v是傳輸秩並且p

是相干服務TRP的集。 In some examples, the network (e.g., gNB) can signal a power indicator to the UE. The power indicator can indicate that at least one TRP in the selected TRP set, such as the p-th TRP, is transmitted at full power. For example, the p-th TRP with full power is determined by p = arg max { c ₁ , c ₂ , c ₃ , c ₄ }, where

is the precoder normalization factor for the pth TRP, and v is the transmission rank and p

Is a set of related service TRPs.

是TRP功率調節預編碼器。 W ^{( p )}是UE報告的CJT預編碼器。第p個TRP的預編碼器範數

意味著第

個TRP傳輸全功率。 The precoder used by the pth TRP is power-scaled by factor c = max { c ₁ , c ₂ , c ₃ , c ₄ } as follows,

is the TRP power adjustment precoder. W ^{( p )} is the CJT precoder reported by the UE. The precoder norm of the pth TRP

It means

TRP transmits full power.

The UE can use the power indicator to estimate the CQI of the CSI report.

Figures 29A to 29B show an example of a 4 TRP CJT transmission scenario. The precoder normalization factors { c1 , c2 , c3 _, c4 } are determined to be {0.3, 0.4, 0.2 _{, 0.1} }. Therefore, TRP2 is determined to be transmitted at full power. And the power adjustment factor is determined to be 0.4. All 4 TRPs can be power amplified by _the same adjustment factor. There is no impact on interference between TRPs. In one example, the UE and the network can each determine the precoder normalization factor and the adjustment factor. In one example, the UE can report the precoder normalization factor and/or the adjustment factor to the network.

Example #13 - Power Indicator

In some examples, a power indicator from the network may indicate to the UE that each TRP in the selected TRP set is to transmit at full power.

其中預編碼器歸一化因數 c _p 被定義為與上述示例中相同。每個TRP的預編碼器範數

意味著每個TRP以全功率發送。UE可以使用功率指示符來估計用於CSI報告的CQI。 The precoder used by the pth TRP is power-adjusted as:

The precoder normalization factor c _p is defined as in the above example. The precoder norm for each TRP is

This means that each TRP is transmitted at full power. The UE can use the power indicator to estimate the CQI for CSI reporting.

Figures 30A to 30B illustrate examples of 4 TRP CJT transmission scenarios. The precoder normalization factors { c1 , c2 , c3 _, c4 } are determined to be {0.3, 0.4, 0.2 _{, 0.1} }. All TRPs perform full power transmission. All 4 TRPs can _be power-amplified by different adjustment factors. Interference between TRPs may increase. In the example, the UE and the network can each determine the precoder normalization factor and the adjustment factor. In one example, the UE can report the precoder normalization factor and/or the adjustment factor to the network.

VIII. CSI Feedback Reduction for Combined Reporting of mTRP and sTRP

In some implementations, in order to mix mTRP NCJT/CJT CSI and sTRP CSI in a CSI report, the UE may be configured with multiple CRIs to indicate which CSI information to estimate. FIG. 15A provides an example of such a configuration. One CRI may indicate at least one CSI-RS resource belonging to at least one resource group. The CRI indexes for sTRP CSI and mTRP CSI may be separate. For a CSI report including sTRP CSI and mTRP CSI, the mTRP CSI may reuse the sTRP CSI to reduce the content size of the mTRP CSI.

(例如，NR DL版本16類型II碼書)。基於本文公開的碼書和預編碼器得出設計，CSI報告可以重新使用sTRP CSI的W ₁、W ₁ W ₂或W ₁ W ₂

，並且減小mTRP CSI的內容大小。例如，UE可以透過CSI報告配置來配置CSI反饋減少資訊。 In some examples, the UE may be configured with the same codebook type for sTRP CSI and mTRP CSI feedback in the CSI reporting configuration. A common codebook design may have a precoder structure W = W ₁ W ₂ (e.g., 3GPP NR DL Type I codebook and Release 15 Type II codebook) or

(e.g., NR DL Release 16 Type II codebook). Based on the codebook and precoder derived design disclosed in this _paper , the CSI report can reuse W1 _, W1W2 _, or W1W2 _of sTRP CSI _.

, and reduce the content size of mTRP CSI. For example, the UE can configure CSI feedback reduction information through CSI reporting configuration.

Example #14 - CSI Feedback Reduction

，並減小mTRP CSI的內容大小。例如，UE被配置為測量並在CSI報告中反饋TRP1、TRP2和TRP3 sTRP CSI和mTRP CSI。UE可以分別測量和得出TRP1、TRP2和TRP3的sTRP預編碼器，並且在mTRP預編碼器得出和反饋上重新使用sTRP預編碼器。例如，TRP1、TRP2、和TRP3的sTRP預編 碼器可以是

所述mTRP預編碼器的W₁矩陣可以是

In some examples, the design for mTRP CSI is derived based on the codebook and precoder, for example, based on the NR Release ₁₇ NCJT CSI architecture or other CSI architectures, the UE may reuse W1 _{, W1W2} , _or W1W2 of sTRP _{CSI .}

, and reduce the content size of mTRP CSI. For example, the UE is configured to measure and feedback TRP1, TRP2 and TRP3 sTRP CSI and mTRP CSI in the CSI report. The UE can measure and derive the sTRP precoder of TRP1, TRP2 and TRP3 respectively, and reuse the sTRP precoder on the mTRP precoder derivation and feedback. For example, the sTRP precoder of TRP1, TRP2, and TRP3 can be

The _W1 matrix of the mTRP precoder can be

If the UE is configured by RRC or MAC CE, the CSI report may not include W ₁ or W ₁ W ₂ of the mTRP precoder.

Example #15 - CSI Feedback Reduction

，並在CSI報告中反饋用於mTRP CSI的附加預編碼器資訊。附加預編碼器資訊可以包括循環相位延遲(cyclic phase delay，CDD)參數或矩陣的索引，以在每個層上應用相移或將複數個層組合成較少的層，如下所示。 In some examples, the network may configure the UE to reuse W ₁ W ₂ or W ₁ W ₂ of sTRP CSI

, and feeds back additional precoder information for mTRP CSI in the CSI report. The additional precoder information may include cyclic phase delay (CDD) parameters or indices into a matrix to apply phase shifts on each layer or to combine multiple layers into fewer layers, as shown below.

For example, configure the UE to measure and feed back TRP1, TRP2, and TRP3 sTRP CSI and mTRP CSI in the CSI report. The sTRP precoder for TRP1, TRP2, and TRP3 can be

，其中，i是子載波索引，並且矩陣D和U是預編碼的CDD部分。矩陣D和U可以是大小為(W ^(k)的層數目，W ^(k)的層數目)的單位矩陣或其他CDD矩陣，例如如下所示的3GPP 36.211 V10.7.0小節6.3.4.2.2 CDD設計：

其中，v是W ^(k)的層數目，並且N _t 是總TX天線數目。下表提供了D和U的示例。 mTRP{TRP1, TRP2, TRP3} precoder can be W ( i )=

, where i is the subcarrier index, and matrices D and U are the CDD part of the precoding. Matrices D and U can be unit matrices of size (number of layers of W ^{( k )} , number of layers of W ^{( k )} ) or other CDD matrices, such as 3GPP 36.211 V10.7.0 section 6.3.4.2.2 CDD design as shown below:

Where v is the number of layers of W ^{( k )} , and Nt is the total number _of TX antennas. The following table provides examples of D and U.

Example #16 - CSI Feedback Reduction

For example, configure the UE to measure and feed back TRP1, TRP2 and TRP3 sTRP CSI and mTRP CSI in the CSI report. The sTRP precoder for TRP1, TRP2 and TRP3 can be

其中i是子載波或子帶索引，並且 Φ (i)可以是在每個層上應用相移或者將複數個層組合成較少的層的矩陣。如果 Φ (i)是應用相移的矩陣，則其可以是

。 Φ (i)是包括相位的v×v對角矩陣。v是W(i)的層數。 Φ (i)可以被設計成應用相移、幅度變化和層組合。下面提供 Φ (i)的一些示例。 The mTRP{TRP1, TRP2, TRP3} precoder may be

where i is the subcarrier or subband index and Φ ( i ) can be a matrix to apply phase shifts on each layer or to combine multiple layers into fewer layers. If Φ ( i ) is a matrix to apply phase shifts, it can be

Φ ( i ) is a v × v diagonal matrix including the phase. v is the number of layers of W ( i ). Φ ( i ) can be designed to apply phase shifts, amplitude variations, and layer combinations. Some examples of Φ ( i ) are provided below.

IX. Codebook Design Based on Version 17fe Type II PS Codebook

1. W ₁ Design: In some examples, there are two possible designs for the W ₁ matrix.

Select TRP port by port

Cross-TRP port selection

個預編碼的CSI-RS，其中，N _p 是協作TRP的數目，並且2L _p 表示第p個協作TRP中的SD/SD-FD對(預編碼的CSI-RS埠)的數目。這種預編碼的CSI-RS的簡單示例是當gNB確定逐個TRP的SD/FD基時。UE還可以按照W ₀從N _p 個協作TRP中選擇

個服務TRP。UE可以從用於第p'個服務TRP的2L _p' 個埠中選擇2K _p' 個埠。該選擇可以是極化共同和自由的，即，從

個可能組合中從2L _p' 個埠中選擇2K _p' 個埠。 For per-TRP port selection, in some examples, the gNB may send PCSI _{- RS} =

precoded CSI-RS, where N _p is the number of coordinated TRPs and 2 L _p represents the number of SD/SD-FD pairs (precoded CSI-RS ports) in the pth coordinated TRP. A simple example of such precoded CSI-RS is when the gNB determines the SD/FD basis on a TRP-by-TRP basis. The UE can also select from the N _p coordinated TRPs according to W ₀

The UE may select 2 K _p' ports from the 2 L _p' ports for the p'th serving TRP. The selection may be polar common and free, i.e., from

Select 2 K _p' ports from the 2 L _p' possible combinations.

For cross-TRP port selection, which can be expected to be derived from the UL channels, the gNB can perform coordinated beamformed CSI-RS transmission from all coordinating TRPs. For example, the gNB can derive the SD-FD basis from the joint mTRP channels as shown in Figure 31 (gNB implementation issue). Based on the UL channels, the gNB can even send precoded CSI-RS with different powers from different TRPs.

個組合中以極化共同和自由的方式從P _CSI-RS 個埠中選擇K ₁個埠。 The total number of precoded (beamformed) CSI-RS ports can be PCSI _{- RS} . As shown in FIG. 32, the UE can obtain

K ₁ ports are selected from the PCSI _{- RS} ports in a polarized common and free manner in the combinations.

2. W2 _Design : Depending on _the W1 method used, there are two possible designs. For per _- W1 TRP, it can be expected that the same design principles of _the W2 design disclosed above can be used. For cross-TRP W1 _, the UE essentially sees multiple TRPs as a single giant TRP and performs port selection on a single precoded mTRP channel as described above, so _the W2 design can follow the traditional Release ₁₇ W2 design.

，使得

。即，逐個TRP FD基向量的並集是整體配置的N個FD基。 3. Wf _design : In the 3GPP Release 17 design, the UE is configured with N = 2 or N = 4 consecutive DFT vectors starting from 0, from which _the UE selects M = 2 vectors for Wf . Since most of the frequency selectivity in the channel can be handled by the precoded CSI-RS, the main purpose _of this Wf is to compensate for the residual frequency selectivity and imperfect delay reciprocity. Further, Wf _design can consider TRP _- specific FD basis selection. For example, TRPp selects Mp FD basis from N = 2 or N = 4 consecutive DFT vectors. However, for all TRPs, the number of selected FD basis is

, so that

That is, the union of the TRP-by-TRP FD basis vectors is the N FD basis of the overall configuration.

X. Other Examples of mTRP Measurement and Transmission

In a first example, a method for wireless communication of a UE includes the following steps: - receiving signaling from a network entity to indicate a CSI report configuration, wherein the channel state information report configuration includes at least one codebook configuration, and at least one power indicator and CSI feedback reduction information, and is associated with at least one CSI-RS resource configuration for channel measurement, wherein the at least one CSI-RS resource configuration associates at least two resource groups with at least one channel measurement selection information; - estimating channel information based on the CSI report configuration; - obtaining at least one PMI and CQI based on the estimated channel information, and at least one power indicator and CSI feedback reduction information; and - sending a CSI report to the network entity.

In a second example based on the first example, the at least one channel measurement selection information indicates which CSI-RS resources should be estimated to obtain the at least one PMI; in a third example based on the first example, each resource group includes at least one CSI-RS resource, and the UE considers that at least one CSI-RS resource in the resource group is transmitted from a co-located geographical location.

In a fourth example based on the second example, if one of the at least one channel measurement selection information indicates at least two CSI-RS resources belonging to at least two different resource groups, the UE considers that the CSI-RS resources indicated by the at least one channel measurement selection information are simultaneously transmitted for JT transmission.

In a fifth example based on the first example, at least one codebook configuration indicates at least one codebook parameter set associated with at least one CSI-RS resource configuration or at least one channel measurement selection information.

In a sixth example based on the fifth example, the at least one codebook parameter set includes at least one of the following information: - the number of beam vectors Lp associated with the p-th CSI-RS resource or resource group indicated by the corresponding channel measurement selection information; - the NZC selection ratio _βp associated with the p-th CSI-RS resource or resource group indicated by the corresponding channel measurement selection _information .

In a seventh example based on the first example, each PMI is derived from at least two of the W ₁ , W ₂ , and W _f codebook matrices.

In an eighth example based on the seventh example, the _W1 codebook matrix has a block diagonal structure having at least two sub-matrices in its diagonal, and a p-th sub-matrix of the at least two sub-matrices includes a spatial beam vector associated with a p-th CSI-RS resource or resource group indicated by the corresponding channel measurement selection information.

In a ninth example based on the seventh example, the _W2 codebook matrix contains complex combination coefficients of the beam vectors in _W1 and the DFT-based delay vectors in _Wf .

In a tenth example based on the seventh example, the W _f codebook matrix includes a DFT-based delay vector.

In an eleventh example based on the seventh example, each PMI is also derived from a resource selection matrix W ₀ , and W ₀ indicates which CSI-RS resource or resource group indicated by the corresponding channel measurement selection information is more important.

In a twelfth example based on the eleventh example, the network entity uses high layer signaling to indicate to the UE whether to use the resource selection matrix W ₀ .

In a thirteenth example based on the seventh example, the precoding coefficients of W ₁ , W ₂ and W _f further consider at least one power indicator for power regulation, wherein the at least one power indicator is indicated by a network entity via high layer signaling.

In a fourteenth example based on the first example, the at least one CQI is calculated and reported based on the at least one power indicator.

In a fifteenth example based on the first example, each codebook configuration is associated with one of the at least one channel measurement selection information.

In a sixteenth example based on the seventh example, the _W1 codebook matrix has a block diagonal structure having at least two sub-matrices in its diagonal, and a p-th sub-matrix of the at least two sub-matrices is a selection matrix including a single non-zero element in each column and is associated with a p-th CSI-RS resource or resource group indicated by the corresponding channel measurement selection information.

XI. Other Examples of mTRP Measurement and Transmission

FIG. 33 shows a process 3300 for mTRP CSI measurement and reporting according to an embodiment of the present invention. Process 3300 may start from step S3301 and proceed to step S3310.

In step S3310, a CSI report configuration is received at the UE from the base station. The CSI report configuration is associated with a CSI-RS resource set. Each CSI-RS resource may correspond to one or more TRPs among a plurality of TRPs.

In step S3320, channel measurement can be performed based on CSI-RS resources sent from multiple TRPs.

In step S3330, the PMI can be determined based on the measurement results of the channel measurement. The PMI can correspond to the precoder matrix denoted as W of the type II CSI codebook. For example, the PMI may include a plurality of indicators indicating elements belonging to the precoder matrix. The precoder matrix may have an SD basis vector matrix denoted as W _1. The SD basis selection of the SD basis vector matrix may be TRP-specific. For example, an SD basis may be selected for each TRP. Each TRP may have a corresponding set of SD basis vectors.

In step S3340, a CSI report may be sent to the base station. The CSI report includes the PMI. Process 3300 proceeds to step S3399 and terminates at step S3399.

FIG. 34 shows another process 3400 for mTRP CSI measurement and reporting according to an embodiment of the present invention. Process 3400 starts from step S3401 and proceeds to step S3410.

In step S3410, a CSI report configuration is received at the UE from the base station. The CSI report configuration is associated with a CSI-RS resource set. Each CSI-RS resource may correspond to one or more TRPs among a plurality of TRPs.

In step S3420, channel measurement is performed based on CSI-RS resources sent from multiple TRPs.

In step S3430, the PMI is determined based on the measurement results of the channel measurement. The PMI may correspond to a precoder matrix represented as W of a type II CSI codebook. The precoder matrix may have an SD/FD coefficient matrix (or a linear combination coefficient matrix) represented as W _2. The coefficient columns in the SD/FD coefficient matrix correspond to the SD basis vectors in the SD basis vector matrix represented as W _1. The coefficient rows in the SD/FD coefficient matrix correspond to the FD basis vectors in the FD basis vector matrix represented as W _f . The PMI includes an FD basis indicator. The FD basis indicator indicates that the FD basis selection corresponding to any TRP in the SD/FD coefficient matrix is independent of the FD basis selection of any other TRP.

In step S3440, a CSI report is sent to the base station. The CSI report includes the PMI. Process 3400 proceeds to step S3499 and terminates at step S3499.

FIG. 35 shows another process 3500 for mTRP CSI measurement and reporting according to an embodiment of the present invention. Process 3500 starts from step S3501 and proceeds to step S3510.

In step S3510, a CSI report configuration is received from a base station at the UE. The CSI report configuration may be associated with a CSI-RS resource set. Each CSI-RS resource may correspond to one or more of a TRP. The CSI-RS resources may be organized into one or more resource groups. The CSI report configuration includes one or more antenna configurations ( _N1 , _N2 ). Each antenna configuration corresponds to one or more TRPs in a plurality of TRPs. One or more antenna configurations correspond to one or more resource groups, respectively. _N1 and _N2 are the numbers of antenna ports corresponding to one or more TRPs having the same polarization direction in the vertical and horizontal directions, respectively.

In step S3520, channel measurement is performed based on CSI-RS resources corresponding to a plurality of TRPs.

In step S3530, the PMI may be determined based on the measurement result of the channel measurement and one or more antenna configurations (N ₁ , N ₂ ).

In step S3540, a CSI report is sent to the base station. The CSI report includes the PMI. Process 3500 proceeds to step S3599 and terminates at step S3599.

XII. Exemplary Devices

FIG. 36 shows an exemplary device 3600 according to an embodiment of the present invention. Device 3600 may be configured to perform various functions according to one or more embodiments or examples described herein. Therefore, device 3600 may provide a device for implementing the mechanisms, techniques, processes, functions, elements, and systems described herein. For example, in the various embodiments and examples described herein, device 3600 may be used to implement the functions of a UE or BS (controlling a TRP). Device 3600 may include a general-purpose processor or a specially designed circuit to implement various functions, elements, or processes described in various embodiments. Device 3600 may include a processing circuit 3610, a memory 3620, and a radio frequency (RF) module 3630.

In various examples, the processing circuit 3610 may include circuits configured to perform the functions and processes described herein with or without software. In various examples, the processing circuit 3610 may be a digital signal processor (DSP), an application specific integrated circuit (ASIC), a programmable logic device (PLD), a field programmable gate array (FPGA), a digitally enhanced circuit, or a similar element or a combination thereof.

In some other examples, the processing circuit 3610 can be configured to execute program instructions to perform various functions and processes described herein (Central Processing Unit, CPU). Therefore, the memory 3620 can be configured to store program instructions. When executing program instructions, the processing circuit 3610 can perform these functions and processes. The memory 3620 can also store other programs or data, such as operating systems, applications, etc. The memory 3620 can include non-temporary storage media, such as read-only memory (ROM), random-access memory (RAM), flash memory, solid-state memory, hard disk drive, optical disk drive, etc.

In one embodiment, RF module 3630 receives processed data signals from processing circuit 3610 and converts the data signals into beamforming wireless signals transmitted via antenna array 3640, and vice versa. In some examples, RF module 3630 may include a digital to analog converter (DAC), an analog to digital converter (ADC), an upconverter, a downconverter, filters and amplifiers for receiving and transmitting operations. In some examples, RF module 3630 may include a multi-antenna circuit for beamforming operations. For example, the multi-antenna circuit may include an uplink spatial filter circuit that adjusts the amplitude of an analog signal, an uplink spatial filter circuit, and a downlink spatial filter circuit. Antenna array 3640 may include one or more antenna arrays organized into a plurality of antenna panels or antenna groups.

Device 3600 may optionally include other components, such as input and output devices, additional or signal processing circuits, etc. Thus, device 3600 is capable of performing other additional functions, such as running applications and processing alternative communication protocols.

The processes and functions described herein may be implemented as a computer program that, when executed by one or more processors, causes one or more processors to perform the corresponding processes and functions. The computer program may be stored or distributed on a suitable medium, such as an optical storage medium or solid state medium provided with or as part of other hardware. The computer program may also be distributed in other forms, such as via the Internet or other wired or wireless telecommunications systems. For example, a computer program may be obtained and loaded into a device, including obtaining the computer program via physical media or a distributed system (such as a server connected to the Internet).

A computer program may be accessed from a computer-readable medium, wherein the computer-readable medium is used to provide program instructions for use by or in connection with a computer or any instruction execution system. The computer-readable medium may include any device for storing, communicating, transmitting or transferring a computer program for use by or in connection with an instruction execution system, device or equipment. The computer-readable medium may be a magnetic, optical, electronic, electromagnetic, infrared or semiconductor system (or device or equipment) or a transmission medium. The computer-readable medium may include a computer-readable non-temporary storage medium, such as semiconductor or solid-state memory, magnetic tape, removable computer disk, RAM, ROM, disk and optical disk. The computer-readable non-temporary storage medium may include all types of computer-readable media, including magnetic storage media, optical storage media, flash memory media, and solid-state storage media.

Although aspects of the present invention have been described in conjunction with specific exemplary embodiments, various substitutions, modifications, and variations may be made to these examples. Therefore, the embodiments described herein are intended to be illustrative rather than restrictive. Changes may be made within the scope of the claims without departing from the scope of the claims.

S3401, S3410, S3420, S3430, S3440, S3499: Steps

Claims (14)

A method for measuring and transmitting multiple transmission and reception points, comprising: receiving a channel state information report configuration from a base station at a user equipment, the channel state information report configuration being associated with a channel state information reference signal resource set, the channel state information reference signal resource set corresponding to a plurality of transmission and reception points; performing a channel measurement based on the channel state information reference signal resources corresponding to the plurality of transmission and reception points; determining a precoder matrix indicator based on a measurement result of the channel measurement, a first precoder matrix indicator corresponding to a first precoder matrix represented as W of a type II channel state information codebook, the first precoder matrix having a first spatial domain/frequency domain coefficient matrix represented as W ₂ , the coefficient columns in the first spatial domain/frequency domain coefficient matrix being the same as the coefficient columns represented as W ₁ , the coefficient rows in the first spatial domain/frequency domain coefficient matrix correspond to the frequency domain basis vectors in the frequency domain basis vector matrix represented as Wf _, the first precoder matrix indicator includes a first frequency domain basis indicator, and the first frequency domain basis indicator indicates that the frequency domain basis selection corresponding to any transmitting and receiving point in the first spatial domain/frequency domain coefficient matrix is independent of the frequency domain basis selection of any other transmitting and receiving point; and sending a channel status information report to the base station, the channel status information report including the precoder matrix indicator. The measurement and transmission method of multiple transmission receiving points as described in claim 1, wherein the first frequency domain base indicator includes an initial window position indicator and a frequency domain base index for each transmission receiving point. The measurement and transmission method for multiple transmission and reception points as described in claim 1 further comprises: determining a second precoder matrix indicator, the second precoder matrix indicator is based on a second precoder matrix of the type II channel state information codebook, the second precoder matrix has a second spatial domain/frequency domain coefficient matrix, the second precoder matrix indicator includes a second frequency domain basis indicator, the second frequency domain basis indicator indicates that the frequency domain basis selection in the second spatial domain/frequency domain coefficient matrix is common to the plurality of transmission and reception points. The measurement and transmission method of multiple transmission receiving points as described in claim 3, wherein the second frequency domain base indicator includes only one initial window position indicator and only one frequency domain base index of the plurality of transmission receiving points. A method for measuring and transmitting multiple transmission and reception points as described in claim 1, wherein non-zero coefficients are selected from the first spatial domain/frequency domain coefficient matrix across the plurality of transmission and reception points. A method for measuring and transmitting multiple transmission and reception points as described in claim 1, wherein a strongest coefficient is selected from the first spatial domain/frequency domain coefficient matrix across the plurality of transmission and reception points. A measurement and transmission method for multiple transmission and reception points as described in claim 1, wherein a reference amplitude coefficient is selected from the first spatial domain/frequency domain coefficient matrix across the plurality of transmission and reception points. A method for measuring and transmitting multiple transmitting and receiving points as described in claim 1, wherein a transmitting and receiving point-specific reference amplitude coefficient is selected from the first spatial domain/frequency domain coefficient matrix. A measurement and transmission method for multiple transmitting and receiving points as described in claim 8, wherein the reference amplitude coefficients specific to the transmitting and receiving points are polarization common. A method for measuring and transmitting multiple transmitting and receiving points as described in claim 8, wherein the transmitting and receiving point specific reference amplitude coefficient is polarization specific. The measurement and transmission method of multiple transmission and reception points as described in claim 1, wherein the first precoder matrix indicator includes a common non-zero coefficient bitmap of the transmission and reception points, and the common non-zero coefficient bitmap of the transmission and reception points indicates the non-zero coefficient position in the first spatial domain/frequency domain coefficient matrix. The measurement and transmission method for multiple transmission and reception points as described in claim 1, wherein the first precoder matrix indicator includes a transmission and reception point specific non-zero coefficient bitmap, and the transmission and reception point specific non-zero coefficient bitmap indicates the non-zero coefficient position in the first spatial domain/frequency domain coefficient matrix. A device for measuring and transmitting multiple transmission and reception points, the device comprising a circuit, the circuit: receiving a channel state information report configuration from a base station, the channel state information report configuration being associated with a channel state information reference signal resource set, the channel state information reference signal resource set corresponding to a plurality of transmission and reception points; performing a channel measurement based on the channel state information reference signal resources corresponding to the plurality of transmission and reception points; determining a precoder matrix indicator based on a measurement result of the channel measurement, a first precoder matrix indicator corresponding to a first precoder matrix represented as W of a type II channel state information codebook, the first precoder matrix having a W represented as W ₂ , wherein the coefficient columns _in the first spatial domain/frequency domain coefficient matrix correspond to the spatial domain basis vectors in a spatial domain basis vector matrix denoted as W1 , the coefficient rows in the first spatial domain/frequency domain coefficient matrix correspond to the frequency domain basis vectors in a frequency domain basis vector matrix denoted as Wf _, the first precoder matrix indicator includes a first frequency domain basis indicator, and the first frequency domain basis indicator indicates that the frequency domain basis selection corresponding to any transmitting and receiving point in the first spatial domain/frequency domain coefficient matrix is independent of the frequency domain basis selection of any other transmitting and receiving point; and sending a channel status information report to the base station, the channel status information report including the precoder matrix indicator. A non-transitory computer-readable medium stores instructions for executing a method for measuring and transmitting multiple transmission and reception points, comprising the following steps: receiving a channel state information report configuration from a base station, the channel state information report configuration being associated with a channel state information reference signal resource set, the channel state information reference signal resource set corresponding to a plurality of transmission and reception points; performing a channel measurement based on the channel state information reference signal resources corresponding to the plurality of transmission and reception points; determining a precoder matrix indicator based on a measurement result of the channel measurement, a first precoder matrix indicator corresponding to a first precoder matrix represented as W of a type II channel state information codebook, the first precoder matrix having a W represented as W ₂ , wherein the coefficient columns _in the first spatial domain/frequency domain coefficient matrix correspond to the spatial domain basis vectors in a spatial domain basis vector matrix denoted as W1 , the coefficient rows in the first spatial domain/frequency domain coefficient matrix correspond to the frequency domain basis vectors in a frequency domain basis vector matrix denoted as Wf _, the first precoder matrix indicator includes a first frequency domain basis indicator, and the first frequency domain basis indicator indicates that the frequency domain basis selection corresponding to any transmitting and receiving point in the first spatial domain/frequency domain coefficient matrix is independent of the frequency domain basis selection of any other transmitting and receiving point; and sending a channel status information report to the base station, the channel status information report including the precoder matrix indicator.

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