Port selection codebook enhancements

Abstract

Apparatuses and methods for port selection codebook configuration are provided. A user equipment (UE) can decode a channel state information (CSI) report configuration (CSI-ReportConfig) from a base station. The CSI-ReportConfig indicates at most L CSI-reference signal (CSI-RS) ports for the UE to select from P CSI-RS ports configured for measuring and reporting CSI. The UE determines CSI-RS ports selected from the P CSI-RS ports. The selected CSI-RS ports include the L CSI-RS ports or fewer CSI-RS ports. The UE generates a port selection matrix W1 corresponding to the selected CSI-RS ports. The UE also generates an indication of the port selection matrix W1 to the base station. The CSI-ReportConfig can further configure the UE to select a frequency basis subset. The UE determines the selected frequency basis subset and generates a frequency basis selection matrix W f .

Description

Technical Field

[0001] This application generally relates to wireless communication systems, including port selection codebook configuration. Background Technology

[0002] Wireless mobile communication technologies use various standards and protocols to transmit data between base stations and wireless communication devices. Wireless communication system standards and protocols can include, for example, 3GPP Long Term Evolution (LTE) (such as 4G), 3GPP New Radio (NR) (such as 5G), and the IEEE 802.11 standard for Wireless Local Area Networks (WLANs) (often referred to within industry organizations as...). ).

[0003] As envisioned by 3GPP, different wireless communication system standards and protocols can use various radio access networks (RANs) to enable RAN base stations (which are sometimes also called RAN nodes, network nodes, or simply nodes) to communicate with wireless communication equipment called user equipment (UEs). 3GPP RANs may include, for example, Global System for Mobile Communications (GSM), Enhanced Data Rate GSM Evolution (EDGE) RAN (GERAN), Universal Terrestrial Radio Access Network (UTRAN), Evolved Universal Terrestrial Radio Access Network (E-UTRAN), and / or Next Generation Radio Access Network (NG-RAN).

[0004] Each RAN can use one or more Radio Access Technologies (RATs) for communication between the base station and the UE. For example, GERAN implements the GSM and / or EDGE RAT, UTRAN implements the Universal Mobile Telecommunications System (UMTS) RAT or other 3GPP RATs, E-UTRAN implements the LTE RAT (sometimes simply referred to as LTE), and NG-RAN implements the NR RAT (sometimes also referred to herein as the 5G RAT, 5G NR RAT, or simply NR). In some deployments, E-UTRAN may also implement the NR RAT. In some deployments, NG-RAN may also implement the LTE RAT.

[0005] The base stations used by a RAN can correspond to that RAN. An example of an E-UTRAN base station is an Evolved Universal Terrestrial Radio Access Network (E-UTRAN) Node B (also commonly referred to as Evolved Node B, Enhanced Node B, eNodeB, or eNB). An example of an NG-RAN base station is a Next Generation Node B (sometimes also called gNodeB or gNB).

[0006] The RAN provides communication services to external entities through its connection with the core network (CN). For example, E-UTRAN can utilize the evolved packet core network (EPC), while NG-RAN can utilize the 5G core network (5GC). Attached Figure Description

[0007] To facilitate identification of any particular element or action being discussed, one or more of the most significant digits in the reference numerals refer to the drawing number in which the element was first introduced.

[0008] Figure 1 The PMI matrix (codebook) used in some embodiments herein is shown.

[0009] Figure 2 The CQI subband relative to the PMI subband is shown in one embodiment according to R=1 / 2.

[0010] Figure 3 The location of Mi base stations that can be reported by the UE to the base station according to one implementation scheme is shown.

[0011] Figure 4 A method for a UE according to one embodiment is shown.

[0012] Figure 5 A method for a UE according to one embodiment is shown.

[0013] Figure 6 A method for a base station according to one embodiment is shown.

[0014] Figure 7 An exemplary diagram illustrating a precoding structure associated with a Type II CSI report is shown, which can be used with certain implementations.

[0015] Figure 8 An exemplary diagram illustrating the report structure that the UE reports back to the base station is shown, and this report structure can be used with certain implementations.

[0016] Figure 9 An exemplary diagram illustrating a CBSR associated with a Type II CSI report is shown, which can be used with certain implementations.

[0017] Figure 10 An exemplary diagram illustrating a CBSR associated with a Type II CSI report is shown, which can be used with certain implementations.

[0018] Figure 11 A diagram illustrating an example of the limitations of individual space basis and frequency basis according to some implementation schemes is shown.

[0019] Figure 12 A diagram illustrating an example of joint space-frequency constraints according to some implementation schemes is shown.

[0020] Figure 13 A diagram of an exemplary precoder structure with frequency compression according to some implementation schemes is shown.

[0021] Figure 14 An exemplary architecture of a wireless communication system according to the embodiments disclosed herein is shown.

[0022] Figure 15 A system for performing signaling between a wireless device and a network device according to an embodiment disclosed herein is shown. Detailed Implementation

[0023] Various embodiments are described with respect to the UE. However, references to the UE are provided for illustrative purposes only. Exemplary embodiments may be used with any electronic component capable of establishing a connection to a network and configured with hardware, software, and / or firmware for exchanging information and data with the network. Therefore, the UE described herein is used to represent any suitable electronic component.

[0024] Many wireless communication standards provide the use of known signals (e.g., pilots or reference signals) for a variety of purposes, such as synchronization, measurement, equalization, and control. For example, in cellular wireless communication, a reference signal (RS) can be provided to deliver a reference point for downlink power. When a wireless communication device or mobile device (i.e., the UE) attempts to determine the downlink power (e.g., the power of a signal from a base station, such as an eNB for LTE and a gNB for NR), the device measures the power of the reference signal and uses that power to determine the downlink cell power. The reference signal also assists the receiver in demodulating the received signal. Because the reference signal includes data known to both the transmitter and the receiver, the receiver can use it to determine / identify various characteristics of the communication channel. This is often referred to as channel estimation, which is used in many high-end wireless communications such as LTE and 5G-NR communications. The known channel properties of the communication link in wireless communication are called channel state information (CSI). CSI provides information indicating, for example, combined effects of scattering, fading, and power attenuation with distance. CSI enables the adaptation of transmission to current channel conditions, which can be used to achieve reliable communication at high data rates in multi-antenna systems.

[0025] Typically, multi-antenna systems use precoding to improve communication. Precoding is an extension of beamforming that supports multi-stream (or multi-layer) transmission in multi-antenna wireless communication and is used to control the differences in signal properties between corresponding signals transmitted from multiple antennas by modifying the signal transmitted from each antenna according to a precoding matrix. In a sense, precoding can be considered as the process of cross-coupling signals before transmission (in closed-loop operation) to equalize the demodulation performance of each layer. The precoding matrix is ​​typically selected from a codebook of multiple precoding matrix candidates, which are usually selected based on the desired performance level based on any one of several different factors, such as the current system configuration, the communication environment, and / or feedback information from the receiver (e.g., UE) receiving the transmitted signal.

[0026] Feedback information is used to select precoding matrix candidates by defining the same codebook at both the transmitter and receiver and using feedback information from the receiver as an indication of the preferred precoding matrix. In such cases, the feedback information includes content called a precoding matrix index (PMI), which may be based on the properties of the signal received at the receiver. For example, the receiver may determine that the received signal has a relatively low signal-to-noise ratio (SNR) and may accordingly transmit a PMI that will replace the current precoding matrix with a new precoding matrix to increase the SNR.

[0027] In 3GPP NR systems, two types of codebooks, Type I and Type II, have been standardized for CSI feedback supporting advanced MIMO operation. These codebooks are constructed from a beam grid based on two-dimensional (2D) digital Fourier transform (DFT), enabling beam-selective CSI feedback and in-phase combination between the two polarizations based on phase shift keying (PSK). Type II codebook-based CSI feedback also reports the bandwidth and subband amplitude information of the selected beam, allowing for more accurate CSI. This, in turn, provides improved precoded MIMO transmission over the network.

[0028] In some cases, it may be necessary to limit the set of precoding matrix candidates that can be selected from the codebook. For example, a network may prevent a receiver from selecting some precoding matrix candidates while allowing it to select others. This is often referred to as codebook subset restriction (CBSR). CBSR may include the transmission of a CBSR bitmap from the transmitter (e.g., base station) to the receiver (e.g., UE). The CBSR bitmap typically includes bits corresponding to each precoding matrix in the codebook, where the value of each bit (e.g., "0" or "1") indicates to the receiver whether the receiver is restricted to considering the corresponding precoding matrix candidate as the preferred precoding candidate requested from the base station. One disadvantage of CBSR is the increased signaling overhead. For example, in some systems, the CBSR bitmap may contain a large number (e.g., 64) bits per channel, requiring the transmitting equipment to transmit a relatively large amount of information to implement CBSR for all its channels.

[0029] In a multi-user multiple-input multiple-output (MIMO) system, the base station can configure multiple UEs (e.g., two UEs) to report their precoding matrices or precoding matrix candidates in mutually orthogonal directions. To reduce the computational complexity of the UE's CSI (Code Sequence Indicator) calculation, based on uplink measurements, the base station can disregard certain unlikely beams, allowing the UE to avoid testing precoders formed by those disregarded beams. In other words, to reduce computational complexity, based on UL (Upper Limit) measurements, the base station can limit the UE to a smaller search space, so the UE does not have to consider the entire codebook.

[0030] For the 3GPP Release 15 (Rel-15) Type II port selection codebook, the beamforming channel state information reference signal (CSI-RS) utilizes downlink (DL) and uplink (UL) channel reciprocity. For example, the base station estimates the UL channel and, based on channel reciprocity, obtains channel state information about the DL channel. Then, based on the DL channel information, the gNB precodes different ports in the CSI-RS in different ways so that the UE can perform further CSI reporting for CSI refinement. The UE measures the CSI-RS and provides feedback to the base station. For a total number X of CSI-RS ports, X / 2 ports are horizontally polarized (H-pol) and X / 2 ports are vertically polarized (V-pol). L CSI-RS ports are selected from the X / 2 CSI-RS ports. The first CSI-RS port can be selected every d ports (e.g., d is 1, 2, 3, or 4). Then, L consecutive ports (e.g., 1, 2, 4) are selected in a loop.

[0031] The 3GPP Rel-16 Type II port selection codebook enhancement uses the same port selection design as 3GPP Rel-15. When configuring subband PMIs, frequency-domain DFT matrices can be used to compress linear combination coefficients.

[0032] For Type II port selection codebooks, it can be assumed that the base station will precode the CSI-RS based on channel reciprocity (i.e., the DL channel is estimated based on the UL channel). For Frequency Division Multiplexing (FDD), precise channel reciprocity may not exist, especially over long multiplexing distances. However, even for FDD, partial reciprocity may still exist when, for example, the angles of arrival or departure between the DL and UL carriers are similar and / or the channel delay distributions between the DL and UL carriers are similar.

[0033] Figure 1 The PMI matrix (codebook) used in some embodiments herein is shown. In the example shown, the Type II port selection codebook structure consists of... (For simplicity, this article will also use the symbolic representation W = W1 * W2 * W) f Or W = W1W2Wf) is given, where W is the PMI matrix, W1 is the spatial basis selection matrix (also referred to as the port selection matrix W1 in this paper), W2 provides the compression combination coefficients, and W... f It is the frequency basis selection matrix. N is the layer index, N3 is the number of PMI subbands, L is the number of selected ports, M is the number of frequency bases, and H represents the Hermitian matrix or conjugate transpose operation. These and other parameters are shown in other figures and / or described in detail below.

[0034] In some systems, for port selection codebook enhancements utilizing DL / UL reciprocity with angle and / or delay, a codebook structure W = W1 * W2 * W is supported. f The port selection matrix W1 is a freely selectable matrix, while the identity matrix is ​​configured in a special way. The frequency base selection matrix W... f It is a compression matrix based on DFT, where N3 = N CQISubband *R and Mv>=1, where R is the size of the Channel Quality Indicator (CQI) subband divided by the size of the PMI subband, and Mv is the number of selected frequency bases. N3 is the number of PMI subbands used for frequency base selection. At least one value of Mv>1 can be supported. In some such systems, the value of Mv can be explicit (e.g., Mv=2). In other embodiments, support for Mv>1 is an optional feature for the UE, considering the UE complexity associated with codebook parameters. However, for candidate values ​​of R, mechanisms for configuring / indicating to the UE, and / or mechanisms for the UE to select W... f The mechanism for selection / reporting has not yet been determined. Furthermore, or in other systems, W f It can be turned off by the base station. When turned off, W f It can be a completely one vector.

[0035] The implementation scheme in this paper provides a method for W = W1 * W2 * W f The port selection codebook is enhanced. Some implementations provide a design for the port selection matrix W1. Additionally, or in other implementations, a frequency base selection matrix W is provided. f The design.

[0036] 1. Design of port selection matrix W1

[0037] In some implementations, the UE selects L ports from P ports. For example, the UE may select L CSI-RS ports out of a total of P CSI-RS ports for port selection, where P / 2 ports are H-poles and P / 2 ports are V-poles.

[0038] 1.1 Port Selection Matrix W1 Structure

[0039] In a polarization-independent implementation, the port selection matrix W1 is a P×L matrix. Each column of the port selection matrix W1 is P×1, where in each column, only one entry is 1 (indicating the selection of a port) and the other entries are 0. Different columns in the port selection matrix W1 cannot be the same. Therefore, a unique port is selected in each column.

[0040] In another implementation of polarization dependence, the port selection matrix W1 is determined by... Given, where W 1，1 It is a P / 2×L matrix. W 1，1 Each column in the array is P / 2×1, where in each column, only one entry is 1 and all other entries are 0. 1，1 Different columns in the configuration cannot be the same. For example, if 32 ports are configured with 16 H-pol ports and 16 V-pol ports, and if the UE is configured to select 8 of the 32 ports, then the UE selects 4 H-pol ports and 4 V-pol ports.

[0041] In another implementation of polarization dependence, the port selection matrix W1 is determined by... Given, where W 1，1 and W 1，2 Each is a P / 2×L matrix. In W... 1，1 or W 1，2 In each column, only one entry is 1 and all other entries are 0. 1，1 or W 1，2 Different columns in W cannot be the same. 1，2 Can be used with W 1，1 They can be the same or different. Therefore, the V-pol port can be selected in a different way than the H-pol port. In other words, each polarization can be selected independently.

[0042] 1.2 Indicator of Port Selection Matrix W1

[0043] In one implementation, the UE is configured to select L CSI-RS ports. To indicate the P×L port selection matrix W1 discussed above, the UE uses a bit width [log2(C(P,L))], where C is a combination function, for example, The bit width is the number of bits used to report the selection matrix W1.

[0044] In another implementation, when the UE is configured to select L CSI-RS ports and the port selection matrix W1 is determined by... When given, the bit width is

[0045] In another implementation, when the UE is configured to select L CSI-RS ports and the port selection matrix W1 is determined by... When given, the bit width is

[0046] In one implementation, the UE is configured to select any number of CSI-RS ports <= L. To indicate the P×L port selection matrix W1 discussed above, the UE uses a bit width...

[0047] In another implementation, when the UE is configured to select any number of CSI-RS ports <= L and the port selection matrix W1 is determined by... When given, the bit width is

[0048] In another implementation, when the UE is configured to select any number of CSI-RS ports <= L and the port selection matrix W1 is determined by... When given, the bit width is

[0049] 1.3 Determine the CSI-RS port when more than one CSI-RS resource is configured for CMR according to the CSI report.

[0050] For the port selection matrix W1, according to certain implementations, more than one CSI-RS resource for Channel Measurement Resources (CMR) can be configured per CSI report configuration (e.g., per CSI-ReportConfig Information Element (IE)). In one such implementation, the UE determines the total CSI-RS ports as the union of all ports in all CSI-RS resources configured in the CSI-ReportConfig IE. The index of the CSI-RS ports can be based on the CSI-RS Resource Identifier (ID) (i.e., NZP-CSI-RS-ResourceID).

[0051] In another implementation, the UE first reports the selected CSI-RS resource ID (NZP-CSI-RS-ResourceId). Then, the UE reports the port selection made among the CSI-RS ports configured in the reported CSI-RS resource ID (NZP-CSI-RS-ResourceId).

[0052] In another implementation, different CSI-RS resources are associated with different PMI subbands. One CSI-RS resource can be associated with multiple PMI subbands. Each PMI subband can only have one associated CSI-RS resource. For each PMI subband, the same or different port selection matrices can be reported based on the associated CSI-RS resources, and the same number of ports can be selected.

[0053] 1.4 Determining the CSI-RS Port When Configuring More Than One Mode for CSI-RS Resources

[0054] For the port selection matrix W1, according to some implementations, more than one mode (i.e., CSI-RS-ResourceMapping) can be configured for CSI-RS resources. In one such implementation, the UE determines the total number of CSI-RS ports as the union of all ports in all configured modes (i.e., CSI-RSResourceMapping) within the same CSI-RS resource.

[0055] In another implementation, the UE first reports the selected CSI-RS-ResourceMapping in the configured CSI-RS-ResourceMapping. Then, the UE reports the port selection made among the CSI-RS ports configured in the reported CSI-RS-ResourceMapping.

[0056] In another implementation, different CSI-RS-ResourceMappings are associated with different PMI subbands. One CSI-RS-ResourceMapping can be associated with multiple PMI subbands. Each PMI subband can only have one associated CSI-RS-ResourceMapping. For each PMI subband, the same or different port selection matrices can be reported based on the associated CSI-RS-ResourceMapping.

[0057] Some implementations apply different mode constraints. For example, resource mapping may be restricted to non-overlapping resource elements (REs) (e.g., for subcarriers). Alternatively, resource mapping may be restricted to the same number of ports.

[0058] Exemplary implementation of Layer 1.5 independent or layer common port selection matrix W1

[0059] The port selection matrix W1 can be layer-independent or layer-common. For each layer, the symbolic representation of the port selection matrix indicates... in It is a layer index. In some layer-independent implementations, the UE can report independently. In some tier common implementations, the UE is for all tiers. Report a single W1.

[0060] 1.6 Exemplary Implementation of Subband Independent or Subband Common Port Selection Matrix W1

[0061] The port selection matrix W1 can be subband-independent or subband-common. The base station can configure the UE to report N3 PMI subbands. For each subband, the symbolic representation of the port selection matrix indicates... Where n is the subband index. In some subband-independent implementations, the UE can target each subband. Report independently, n = 0, 1, ..., N³-1. In some sub-band common implementations, the UE targets all sub-bands. Report a single W1.

[0062] A hybrid implementation scheme can also be used. For example, when multiple subbands are configured, the UE selects the same port for each subband. However, the UE can select different ports in different subbands.

[0063] 1.7 Exemplary Implementation of Subband-Based Port Selection Restriction

[0064] Some implementations include subband-based port selection restrictions. In such implementations, there may be X CSI-RS ports (total or in each polarization), and PMI subbands may be divided into multiple groups. For each PMI subband group, the UE is configured to, or allowed to, select from a subset of the X CSI-RS ports. Furthermore, for each PMI subband group, the UE is not required to test and / or select CSI-RS ports not in the configured subset.

[0065] 2. Used for the frequency basis selection matrix W f Design

[0066] As discussed above, some implementations provide a frequency basis selection matrix W. f The design can be combined with any of the implementation schemes discussed above for the port selection matrix W1.

[0067] 2.1 When the frequency basis selection matrix W f When the base station is turned off

[0068] In some implementations, the frequency basis selection matrix W fIt can be shut down by the base station. In one such implementation, the PMI matrix is ​​simplified to W = W1, where W1 is a column vector that selects L CSI-RS ports. There are only L non-zero entries in W1, and each non-zero entry is a phase and amplitude factor used to select the corresponding port and then report the combination coefficients of the selected port.

[0069] In another implementation, when the frequency basis selection matrix W f When the base station is turned off, the PMI matrix is ​​simplified to W = W1W2, where W1 is the port selection matrix discussed above and W2 includes more than one column. Each column of W2 corresponds to a PMI subband. For each column in W2, there are at most L non-zero entries. Each non-zero entry is the phase and amplitude factor of the combination coefficients of the corresponding selected port.

[0070] 2.2 Number of PMI subbands used for frequency base selection

[0071] In one implementation, the total number of PMI subbands used for frequency base selection is N. CQISubband *R. N CQISubband R is the number of CQI subbands configured by the network (NW). R is the ratio configured by the NW. As indicated above, R is the size of the CQI subband divided by the size of the PMI subband. In some wireless systems, only R=1 and R=2 are allowed. However, for 3GPP Rel-17, R can be configured to be less than 1 (e.g., 1 / 2, 1 / 4, 1 / 8, etc.). For example, Figure 2 The diagram illustrates the CQI subbands (CQI subband 0, CQI subband 1, CQI subband 2, CQI subband 3, CQI subband 4, CQI subband 5, CQI subband 6) relative to the PMI subbands (PMI subband 0, PMI subband 1, PMI subband 2, PMI subband 3) according to an embodiment where R = 1 / 2. The PMI subband to CQI subband mapping can start from either the lowest or highest frequency.

[0072] 2.3 Network Configuration for Broadband Reports

[0073] In some implementations, the NW can configure broadband reporting for the port selection codebook. For example, the NW can configure the UE for broadband CQI reporting and / or broadband PMI reporting.

[0074] 2.4 Selection of Mv frequency bases from N frequency bases

[0075] In some implementations, for the frequency basis selection matrix W fFrom N frequency bases (subbands), Mv frequency bases are selected. DC (direct current) is selected, i.e., the first frequency base. To indicate the selection of the remaining frequency bases, according to one embodiment, free selection is used, where the UE can select any Mv-1 frequency bases from N-1 frequency bases, and the bit width is...

[0076] In another implementation, to indicate the selection of the remaining frequency bases, the NW configures a list of possible bases from which the UE can choose. For example, the NW may configure a total of D possible selections for Mv-1 frequency bases out of N-1 frequency bases, where the UE can select one of the D possible selections.

[0077] 2.5 NW Configuration of Frequency Base Subset for UE Selection

[0078] In some implementations, for the frequency basis selection matrix W f The NW can be configured to provide a subset of frequency bases for the UE to select. In one such implementation, the subset configuration is based on window constraint selection, wherein the UE is further constrained to select from k*Mv consecutive frequency bases, where k*Mv <N。

[0079] The locations of k*Mv consecutive ports (i.e., Mi ports) can be reported by the UE or configured by the NW. For example, Figure 3 The locations of Mi base stations that can be reported by the UE to the base station are shown. In the example shown, k=2 and the locations of the selected Mi base stations are shown relative to 2Mv-Mi base stations and n-2Mv base stations.

[0080] In another implementation, the NW can configure a list of frequency base subsets for the UE to select. In this example, the locations of the k*Mv ports do not need to be contiguous. Each entry in the list configures a subset of the frequency bases for the UE to select. In some such implementations, the subsets are configured via a bitmap.

[0081] 2.6 Exemplary Quantization and Feedback of the Combination Coefficient Matrix W2

[0082] In some implementations, the coefficients in the combined coefficient matrix W2 may be divided into different groups or subsets. For example, the four different groups may include a first group (group 1) that includes the strongest coefficients of all coefficients (e.g., in one of polarizations H-pol or V-pol), a second group (group 2) that includes the strongest coefficients of the other polarization, a third group (group 3) that includes a subset of the remaining coefficients to be reported, and a fourth group (group 4) that includes the remaining coefficients that will not be reported.

[0083] 2.7 Exemplary determination of the number of coefficients to be reported

[0084] In one implementation, the base station configures a fixed number or percentage (e.g., 25%) of coefficients to be reported by the UE in the combined coefficient matrix W2. In another implementation, the base station configures an upper limit, a lower limit, or both of the upper and lower limits for the number of coefficients to be reported by the UE in the combined coefficient matrix W2. For example, the UE can report an actual number of coefficients without violating the configured upper and / or lower limits.

[0085] 2.8 Example Report of Coefficient Indexes in the Combined Coefficient Matrix W2

[0086] In some implementations, for each group, the UE is configured to report the index (position) of the reported coefficients in the combined coefficient matrix W2. For sub-band indication (i.e., frequency basis selection matrix W2)... f The column indexes of one or more groups of coefficients can be predetermined (i.e., fixed in the standard). Furthermore, or in other implementations, the UE may freely report the column indexes of one or more of these groups. For example, referring to groups 1 through 4 above, the column indexes of group 1 and / or group 2 are predetermined, and it may be useful for the UE to freely report the column indexes of group 3 and group 4.

[0087] For port indication (i.e., frequency basis selection matrix W) f The row indexes of one or more groups of coefficients can be predetermined (i.e., fixed in the standard). Furthermore, or in other implementations, the UE may freely report the row indexes of one or more of these groups. For example, referring to groups 1 through 4 above, the row indexes of group 1 and / or group 2 are predetermined, and it may be useful for the UE to freely report the row indexes of group 3 and group 4.

[0088] 2.9 Exemplary report on phase and amplitude quantization of coefficients in the combined coefficient matrix W2

[0089] In some implementations, the reporting of phase and amplitude quantization of the reported coefficients in the combined coefficient matrix W2 is based on groups (e.g., groups 1 through 4 discussed above). For group 1, phase and amplitude are not reported because the strongest coefficient is used as a reference, such that the strongest coefficient is considered to have an amplitude of 1 and a phase of 0. The UE reports the phase and amplitude quantization of group 2 at a higher resolution (e.g., a larger bit width for amplitude and / or phase) compared to the resolution used to report the phase and amplitude quantization of group 3. However, in other implementations, the UE may report the phase and amplitude quantization of groups 2 and 3 using the same resolution.

[0090] 3.0 Exemplary Methods and Apparatus

[0091] Figure 4This is a flowchart of a method 400 for a UE according to certain embodiments. In block 402, method 400 includes: decoding at the UE a Channel State Information (CSI) Report Configuration (CSI-ReportConfig) from a base station, the CSI-ReportConfig indicating at most L CSI-RS ports for the UE to select from P CSI Reference Signal (CSI-RS) ports configured for measuring and reporting CSI. In block 404, method 400 includes: determining at the UE the CSI-RS ports selected from the P CSI-RS ports, wherein the selected CSI-RS ports include L CSI-RS ports or fewer. In block 406, method 400 includes: generating at the UE a port selection matrix W1 corresponding to the CSI-RS ports selected from the P CSI-RS ports. In block 408, method 400 includes: transmitting the port selection matrix W1 from the UE to the base station.

[0092] In some embodiments of method 400, the port selection matrix W1 is a P×L matrix, wherein each of the L columns of the port selection matrix W1 is P×1, wherein only one entry in each of the L columns includes 1 and the other entries in each of the L columns include 0, and wherein the different columns of the L columns of the port selection matrix W1 are distinct from each other. In some such embodiments in which the UE selects L CSI-RS ports from P CSI-RS ports, the transmission port selection matrix W1 includes the use of bit widths. The transmission port selection matrix W1 is used. In other embodiments where the UE selects fewer than or equal to L CSI-RS ports from P CSI-RS ports, the transmission port selection matrix W1 includes the use of bit width Where C is a combinatorial function.

[0093] In one embodiment of method 400, the port selection matrix W1 is determined by... Given, where W 1，1 Let W be a P / 2×L matrix. 1，1 Each of the L columns in the matrix is ​​P / 2×1, where each of the L columns contains only one entry containing 1 and the other entries in each of the L columns contain 0, where W 1，1 Different columns in the matrix cannot be the same, and the first P / 2 CSI-RS ports are horizontally polarized (H-pol) and the last P / 2 CSI-RS ports are vertically polarized (V-pol). In some such implementations where the UE selects L CSI-RS ports from P / 2 CSI-RS ports, the transmission port selection matrix W1 includes the use of bit width In other embodiments where the UE selects fewer than or equal to L CSI-RS ports from P / 2 CSI-RS ports, the transmission port selection matrix W1 includes the use of bit width

[0094] In one embodiment of method 400, the port selection matrix W1 is determined by... Given, where W 1，1 and W 1，2 Each is a P / 2×L matrix, where W 1，1 or W 1，2 In each of the L columns, only one entry is 1 and all other entries are 0, where W 1，1 or W 1，2 Different columns in the array cannot be the same, and the first P / 2 CSI-RS ports are horizontally polarized (H-pol) and the last P / 2 CSI-RS ports are vertically polarized (V-pol). W 1，2 Can be used with W 1，1 Same. Alternatively, W 1，2 Can be used with W 1，1 Different. In some such implementations, where the UE selects L CSI-RS ports from P / 2 CSI-RS ports, the transmission port selection matrix W1 includes the use of bit width In other embodiments where the UE selects fewer than or equal to L CSI-RS ports from P / 2 CSI-RS ports, the transmission port selection matrix W1 includes the use of bit width

[0095] In one implementation of method 400, CSI-ReportConfig configures more than one CSI-RS resource for channel measurement resources (CMR), wherein the total CSI-RS ports are the union of all ports in all CSI-RS resources configured in CSI-ReportConfig, and wherein the CSI-RS port index is based on the CSI-RS resource identifier (ID).

[0096] In one embodiment of method 400, CSI-ReportConfig configures more than one CSI-RS resource for channel measurement resources (CMR), wherein method 400 further includes: reporting the selected CSI-RS resource identifier (ID); and reporting the port selection configured in the selected CSI-RS resource ID.

[0097] In one embodiment of method 400, the port selection matrix W1 is layer-independent, wherein the transmission port selection matrix W1 includes independently reported... in It is a layer index.

[0098] In one embodiment of method 400, the port selection matrix W1 is layer-common, wherein the transport port selection matrix W1 includes a single port selection matrix W1 reported for all layers.

[0099] In one embodiment of method 400, the port selection matrix W1 is subband independent, wherein the transmission port selection matrix W1 includes independently reported... Where n is the sub-band index.

[0100] In one embodiment of method 400, the port selection matrix W1 is subband common, wherein the transmission port selection matrix W1 includes a single port selection matrix W1 reported for all subbands.

[0101] Figure 5 This is a flowchart of a UE method 500 according to certain implementation schemes. Figure 5 The method 500 shown can be used with Figure 4 The method 400 shown can be used together or independently of Figure 4 Method 400 shown is used. In block 502, method 500 includes: decoding a Channel State Information (CSI) Report Configuration (CSI-ReportConfig) from a base station at the UE, the CSI-ReportConfig being used to configure the UE to select a subset of frequency bases. In block 504, method 500 includes: determining the selected subset of frequency bases. In block 506, method 500 includes: generating a frequency base selection matrix W corresponding to the selected subset of frequency bases. f The precoding matrix index (PMI) matrix W = W1W2W f Where W2 is a matrix including the compression combination coefficients. In block 508, method 500 includes: selecting the frequency basis matrix W... f Report to the base station.

[0102] One implementation of method 500 further includes: processing the shutdown frequency base selection matrix W from the base station. f The instruction is given, where the PMI matrix W is simplified to W = W1, where the port selection matrix W1 is a column vector that selects L CSI-RS ports, where the port selection matrix W1 includes L non-zero entries, and where each of the L non-zero entries includes a phase and amplitude factor for the combination coefficients used to select the corresponding port and report the corresponding port.

[0103] One implementation of method 500 further includes: processing the shutdown frequency base selection matrix W from the base station. finstructions, wherein a PMI matrix W is simplified as W=W1W2, wherein W2 comprises more than one column, each column corresponds to a PMI subband, for each column, there are at most L non-zero entries, and each of the L non-zero entries comprises a phase and an amplitude factor of a combining coefficient for a corresponding port.

[0104] In one embodiment of method 500, the total number of PMI subbands for frequency basis selection is N CQISubband *R, where N CQISubband is the number of channel quality indicator (CQI) subbands configured by the base station, and R is the size of the CQI subband divided by the size of the PMI subband.

[0105] In one embodiment of method 500, CSI-ReportConfig configures the UE for at least one of wideband channel quality indicator (CQI) reporting and wideband PMI reporting.

[0106] In one embodiment of method 500, CSI-ReportConfig configures the UE to select a direct current (DC) frequency basis and any Mv-1 frequency bases among N-1 frequency bases, and use a bit width to report the frequency basis selection matrix W f .

[0107] In one embodiment of method 500, CSI-ReportConfig configures the UE to select one possible choice among D possible choices of Mv-1 frequency bases from the N-1 frequency bases as well as the direct current (DC) frequency basis.

[0108] In one embodiment of method 500, CSI-ReportConfig comprises window-constrained selection of frequency basis subsets, where the UE is constrained to select from consecutive k*Mv frequency bases among the N frequency bases, where k is an integer and k*Mv<N. The method 500 may further comprise: reporting the position of the consecutive k*Mv frequency bases to the base station. Alternatively, the base station may configure the position of the consecutive k*Mv frequency bases.

[0109] In one embodiment of method 500, CSI-ReportConfig comprises a list of frequency basis subsets, where each entry in the list configures a different frequency basis subset for the UE to select.

[0110] Embodiments contemplated herein include an apparatus comprising means for performing one or more elements of method 400 and / or method 500. The apparatus may be, for example, an apparatus of a UE (such as the wireless device 1502 acting as a UE, as described herein).

[0111] The embodiments contemplated herein include one or more non-transitory computer-readable media comprising instructions that, when executed by one or more processors of an electronic device, cause the electronic device to perform one or more elements of method 400 and / or method 500. The non-transitory computer-readable medium may be, for example, the memory of a UE (such as memory 1506 of a wireless device 1502 serving as a UE, as described herein).

[0112] The embodiments contemplated herein include an apparatus comprising logic, modules, or circuitry for performing one or more elements of method 400 and / or method 500. This apparatus may be, for example, a device of a UE (such as wireless device 1502 as a UE, as described herein).

[0113] The embodiments contemplated herein include an apparatus comprising: one or more processors and one or more computer-readable media including instructions that, when executed by the one or more processors, cause the one or more processors to perform one or more elements of method 400 and / or method 500. The apparatus may be, for example, an apparatus of a UE (such as wireless device 1502 as a UE, as described herein).

[0114] The embodiments contemplated herein include a computer program or computer program product comprising instructions, wherein when executed by a processor, the program causes the processor to perform one or more elements of method 400 and / or method 500. The processor may be a processor of the UE (such as processor 1504 as a wireless device 1502 of the UE, as described herein). These instructions may, for example, reside in the processor and / or in the memory of the UE (such as memory 1506 as a wireless device 1502 of the UE, as described herein).

[0115] Figure 6This is a flowchart of method 600 for a base station according to certain embodiments. In block 602, method 600 includes: generating at the base station a Channel State Information (CSI) Report Configuration (CSI-ReportConfig) for a User Equipment (UE), the CSI-ReportConfig indicating at most L CSI-RS ports for the UE to select from P CSI Reference Signal (CSI-RS) ports configured for measuring and reporting CSI, the CSI-ReportConfig further indicating a subset of frequency bases for the UE to select. In block 604, method 600 includes: receiving at the base station a port selection matrix W1 from the UE corresponding to the CSI-RS ports selected from the P CSI-RS ports. In block 606, method 600 includes receiving at the base station a matrix W2 including compression combination coefficients from the UE. In block 608, method 600 includes receiving at the base station a frequency base selection matrix W corresponding to the selected subset of frequency bases. f In block 610, method 600 includes determining a precoding matrix index (PMI) matrix W = W1*W2*W at the base station. f In block 612, method 600 includes generating a Physical Downlink Shared Channel (PDSCH) demodulation reference signal (DMRS) for UE transmission at the base station using the PMI matrix W.

[0116] In one embodiment of method 600, the port selection matrix W1 is a P×L matrix, wherein each of the L columns in the port selection matrix W1 is P×1, wherein only one entry in each of the L columns includes 1 and the other entries in each of the L columns include 0, and wherein the different columns in the L columns of the port selection matrix W1 are different from each other.

[0117] In one embodiment of method 600, the port selection matrix W1 is determined by... Given, where W 1，1 Let W be a P / 2×L matrix. 1，1 Each of the L columns in the matrix is ​​P / 2×1, where each of the L columns contains only one entry containing 1 and the other entries in each of the L columns contain 0, where W 1，1 Different columns in the array cannot be the same, and the first P / 2 CSI-RS ports are horizontally polarized (H-pol) and the last P / 2 CSI-RS ports are vertically polarized (V-pol).

[0118] In one embodiment of method 600, the port selection matrix W1 is determined by... Given, where W 1，1 and W 1，2 Each is a P / 2×L matrix, where W 1，1 or W1，2 In each of the L columns, only one entry is 1 and all other entries are 0, where W 1，1 or W 1，2 Different columns in the array cannot be the same, and the first P / 2 CSI-RS ports are horizontally polarized (H-pol) and the last P / 2 CSI-RS ports are vertically polarized (V-pol).

[0119] In one implementation, method 600 further includes turning off the frequency basis selection matrix W. f The PMI matrix W is simplified to W = W1, where the port selection matrix W1 is a column vector that selects L CSI-RS ports. The port selection matrix W1 includes L non-zero entries, and each of the L non-zero entries includes the phase and amplitude factors for the combination coefficients of the corresponding port.

[0120] In one implementation, method 600 further includes turning off the frequency basis selection matrix W. f The PMI matrix W is simplified to W = W1W2, where W2 includes more than one column, each column corresponding to a PMI subband, and for each column there are at most L non-zero entries, and each of these L non-zero entries includes the phase and amplitude factors for the combination coefficients of the corresponding port.

[0121] In one embodiment of method 600, the total number of PMI subbands used for frequency base selection is N. CQISubband *R, where N CQISubband R is the number of Channel Quality Indicator (CQI) subbands configured by the base station, and R is the size of the CQI subband divided by the size of the PMI subband.

[0122] In one implementation, method 600 further includes configuring the UE for at least one of a broadband channel quality indicator (CQI) report and a broadband PMI report.

[0123] In one implementation, method 600 further includes configuring the UE to select a DC frequency base and any Mv-1 frequency bases from the N-1 frequency bases and reporting the frequency base selection matrix W using a bit width [log2(C(N-1, Mv-1))]. f .

[0124] In one embodiment, method 600 further includes configuring the UE to select one of the D possible selections of a DC frequency base and Mv-1 frequency bases out of N-1 frequency bases.

[0125] In one embodiment, the method 600 further comprises configuring window constraint selection for frequency basis subsets, wherein a UE is constrained to select from consecutive k*Mv frequency bases out of N frequency bases, where k is an integer and k*Mv<N. In some such embodiments, the method 600 further comprises receiving, at a base station, an indication of the position of the consecutive k*Mv frequency bases from the UE. Alternatively, the method 600 may further comprise configuring the position of the consecutive k*Mv frequency bases for the UE.

[0126] In one embodiment of the method 600, CSI-ReportConfig comprises a list of frequency basis subsets, wherein each entry in the list configures a different frequency basis subset for the UE to select.

[0127] Embodiments contemplated herein include an apparatus comprising one or more elements for performing the method 600. The apparatus may be, for example, an apparatus of a base station (such as the network device 1518 acting as a base station as described herein).

[0128] Embodiments contemplated herein include one or more non-transitory computer-readable media comprising instructions that, when executed by one or more processors of an electronic device, cause the electronic device to perform one or more elements of the method 600. The non-transitory computer-readable media may be, for example, a memory of a base station (such as the memory 1522 of the network device 1518 acting as a base station as described herein).

[0129] Embodiments contemplated herein include an apparatus comprising logic, modules or circuits for performing one or more elements of the method 600. The apparatus may be, for example, an apparatus of a base station (such as the network device 1518 acting as a base station as described herein).

[0130] Embodiments contemplated herein include an apparatus comprising: one or more processors and one or more computer-readable media comprising instructions that, when executed by the one or more processors, cause the one or more processors to perform one or more elements of the method 600. The apparatus may be, for example, an apparatus of a base station (such as the network device 1518 acting as a base station as described herein).

[0131] Embodiments contemplated herein include a signal as described in or associated with one or more elements of the method 600.

[0132] The embodiments contemplated herein include a computer program or computer program product comprising instructions, wherein execution of the program by a processing element causes the processing element to perform one or more elements of method 600. The processor may be a processor of a base station (such as processor 1520 of network device 1518 as a base station, as described herein). These instructions may, for example, reside in the processor and / or in the memory of the base station (such as memory 1522 of network device 1518 as a base station, as described herein).

[0133] Figure 7 An exemplary diagram illustrating a precoding structure associated with a Type II CSI report is shown, which can be used with certain implementations. The CSI report can be sent to the base station to indicate which precoding the UE prefers. In the Type II report, a precoding matrix is ​​reported for each frequency band, and the precoding matrix is ​​represented by a linear combination of a set of L DFT vectors representing each column. As discussed herein, L corresponds to the number of ports selected. Figure 7 As shown, there can be a specified number of N³ subbands (or N³ PMI subbands) and a corresponding precoding matrix W for each subband. Each precoding matrix includes two columns, w 1 and w 2 Each column corresponds to a precoding vector for one layer. For each layer, the precoding vector can be further divided into two parts, a first polarization and a second polarization. L DFT vectors are common to all subbands and are used in subband-specific combinations. Specifically, each column vector is a weighted sum of the L vectors. The weighting (or combination) coefficients of the combination / combination weights are... Figure 7 The values ​​are indicated by c0, c1, and c2. For example... Figure 7 As indicated in the example, v0, v1, and v2 represent three DFT vectors. The UE will choose which three DFT vectors to report to the base station.

[0134] Figure 8 An exemplary diagram illustrating the reporting structure reported by the UE back to the base station is shown, which can be used with certain implementations. Each subband has its own corresponding set of combination coefficients, and the final UE reports the combination coefficients. When considering reports from the UE, Type II overhead is primarily based on subband combination coefficients. Figure 8 The information shown indicates a total of 2L×N3 entries, with multiple bits for amplitude and multiple bits for phase. In one example, in the worst case, there could be 19 subbands, 32 transmit (TX) ports, and a CSI payload size exceeding 1000 bits. Therefore, reducing Type II CSI overhead would be beneficial.

[0135] Figure 9An exemplary diagram illustrating a CBSR associated with a Type II CSI report is shown, which can be used with certain implementations. Figure 9 Instructions on how to configure the CBSR are provided. In general, a bit sequence is provided to the UE. The bit sequence consists of two parts, and each sequence indicates the maximum permissible value for the DFT beam. Therefore, the O1O2 beamgroups are divided into two categories: restricted or unrestricted. For the bases in the unrestricted beamgroup, the broadband amplitude is unrestricted (e.g., the broadband amplitude can have eight different values). For the bases in the restricted beamgroup, the maximum permissible broadband amplitude is configured (e.g., the maximum permissible broadband amplitude can have four different values). That is, the restriction is spatial. Four spatial base groups are selected, and the maximum broadband amplitude of each beam in the corresponding base group is restricted.

[0136] like Figure 9 As shown, there can be two antennas in the vertical dimension (number of antennas [N1] = 2) and two antennas in the horizontal direction (number of antennas [N2] = 2), resulting in sixteen beam groups (BGs). The base station selects four from the sixteen BGs for consideration. In the example shown, BG 1, BG 5, BG 8, and BG 10 are selected. The selection of these four beam groups is indicated by the first sequence B1. For each beam group, the base station further signals to the UE that the short sequence contains eight bits. The eight bits are divided into four groups, each corresponding to one beam in that group. The four groups are... Figure 9 The diagram shows B2. (0) B2 (1) B2 (2) and B2 (3) This indicates four different maximum amplitude levels. Each group contains four beams, and each beam indicates the maximum permissible power the UE can consider when reporting CSI. This allows for maximum amplitude control for spatial beams. Therefore, as... Figure 9 As shown, CBSR confined beam groups BG 1, BG 5, BG 8 and BG 10, each group consisting of N1N2 bases, wherein the maximum broadband amplitude is configured for each beam in each confined beam group.

[0137] Figure 10 An exemplary diagram illustrating a CBSR associated with a Type II CSI report is shown, which can be used with certain implementations. As previously mentioned, overhead can consume significant uplink bandwidth. In some implementations, frequency compression of combined (or weighted) coefficients can be introduced to reduce overhead. Therefore, in addition to the spatial basis considerations (described previously), a frequency basis can also be considered. If the channel is less frequency selective, adjacent coefficients may exhibit similarity. For example, {c i,n3,l} n3＝1 N3are correlated. That is to say, the combination coefficients across frequencies may have a certain correlation (they may be correlated across frequencies). If the correlation is extracted to achieve decorrelation, a small frequency basis set W can be used f to represent the coefficients. Therefore, the combination coefficients ({c can be compressed across the frequency dimension i,n3l} n3＝1 N3 ) to reduce overhead. Then, each coefficient may be based on M bases, where M represents the corresponding number of bases and is less than N3, that is, M<N3. This allows the UE to report a small number of combination coefficients, while also reporting the frequency basis (or multiple frequency bases) to enable the base station to reconstruct the first subband combination coefficient. Therefore, the coding vector can be presented not only in the spatial dimension, but also in the frequency dimension. As Figure 10 pointed out in, W1 represents the spatial basis column (which may also be referred to herein as a port selection matrix), W2 provides combination coefficients for the selected ports of the N3 PMI subbands, and W f represents the frequency basis column.

[0138] In addition to the spatial basis restrictions configured for the base station, the UE may also be restricted to report CSI based on the frequency basis subset for the base station. In some embodiments, the maximum allowable amplitude may be separately configured for the spatial basis and the frequency basis, thereby generating a separate maximum allowable amplitude based on spatial considerations and a separate maximum allowable amplitude based on frequency considerations. The maximum allowable amplitude may be layer-specific, that is, each layer may be configured with different maximum allowable amplitudes of different ranks. At least three different combinations of spatial / frequency basis considerations may be implemented. In the first specific embodiment, the UE may be configured with a restricted spatial basis dependent amplitude and an unrestricted frequency basis dependent amplitude. In the second specific embodiment, the UE may be configured with a restricted frequency basis dependent amplitude and an unrestricted spatial basis dependent amplitude. Finally, in the third specific embodiment, the UE may be configured with a restricted spatial basis dependent amplitude and a restricted frequency basis dependent amplitude.

[0139] Separate spatial restrictions and frequency restrictions.

[0140] In some embodiments, both the maximum allowable amplitude for the spatial basis and the maximum allowable amplitude for the frequency basis may be configured. This may be implemented in multiple different embodiments, which may be grouped into three different alternatives. In the first alternative, the amplitude of each coefficient may be represented by at most three components, as expressed by the formula , where the three components are: the spatial basis dependent amplitude (P i,l (1) ); the frequency basis dependent amplitude (P m,l (3) ); and the amplitude (P that depends on both the spatial basis and the frequency basis i,m,l (2) ); where (P i,l(1) ) and (P i,l (1) Each of these cannot exceed the configured maximum allowable value. In the second alternative scheme, the amplitude of each coefficient can be determined by a single component P. i,m,l It means that P i,m,l It cannot exceed the maximum allowable value configured for the corresponding spatial basis (or basis), and it also cannot exceed the maximum allowable value configured for the corresponding frequency basis (or basis). In the third alternative scheme, the amplitude of each coefficient can be determined by a single component P. i,m,l It means that P i,m,l It cannot exceed the product of the maximum allowable value configured for the corresponding spatial base (or base) and the maximum allowable value configured for the corresponding frequency base (or base).

[0141] Figure 11 A diagram illustrating an example of the limitations of individual space basis and frequency basis according to some embodiments is shown. Figure 11 In the illustrated implementation, a 2-bit indication for each frequency component can be provided to the UE by the base station. That is, a 2-bit amplitude limit can be configured for each frequency base (FC). When the amplitude is set to zero for a given frequency component, the given frequency component is fully limited. In other words, the UE can perform CSI (or PMI) reporting regardless of the given frequency component. Figure 11 As shown, for FC 0, the amplitude is limited to 1; for FC 2, the amplitude is limited to 1 / 2; and for FC 1 and FC 3, CSI reporting is fully limited. Figure 11 In the bottom diagram, frequency basis limitation is indicated on the vertical axis, while spatial basis limitation is indicated on the horizontal axis. In some embodiments, beam groups 1, 5, 8, and 10 are spatially basis limited.

[0142] Joint space-frequency limitation.

[0143] Figure 12 A diagram illustrating an example of joint space-frequency constraints according to some implementation schemes is shown. Figure 12 As shown, the UE can be restricted to reporting a subset of combinations of spatial and frequency bases for the base station configuration. In this case, the UE can be configured with a subset of spatial base groups, where a frequency base restriction set is configured for each spatial base group. When a frequency base is restricted, the UE can perform CSI reporting regardless of that frequency base and its associated spatial base. For each spatial base group, a maximum allowable amplitude can be configured for each base in that group. That is, a maximum allowable amplitude can be indicated for each combination. For each beam group, the frequency components to be used can also be indicated. For the maximum amplitude, the beam group configuration can still be followed.

[0144] exist Figure 12In the example shown, a specific frequency basis constraint is configured for each constrained space beamset. On the other hand, for an unconstrained space beamset, the frequency basis is unconstrained. Figure 11 Compared to the examples shown where frequency bases 1 and 3 are fully constrained (regardless of the spatial basis), in Figure 12 In the examples, spatially unrestricted beamgroups 0 and 15 have no frequency restrictions. However, each spatially restricted beamgroup may also have a frequency base restriction imposed as shown in the figure, as indicated by the corresponding frequency base restriction of each spatially restricted beamgroup (1, 5, 8, and 10).

[0145] In some implementations, frequency base constraints and spatial base constraints may not be applied simultaneously. That is, the constraints may be on a spatial base or a frequency base, depending on certain parameters. For example, the applicability of spatial / frequency constraints may depend on the spatial / frequency granularity. Considering the number of transmit ports or antennas (N1, N2), a smaller number of antennas (e.g., N1 and N2 are both equal to or less than four) may suggest a wider spatial beam and fewer PMI assumptions, because spatial base constraints may be less effective, and therefore frequency base constraints may be preferred. Thus, in some implementations, for CBSR, frequency base constraints, rather than spatial base constraints, may be provided to the UE by the base station. On the other hand, a larger number of antennas (e.g., N1 and N2 are both equal to or greater than 8) may suggest a narrower spatial beam and more PMI assumptions, because each spatial beam may correspond to a single frequency base, and therefore spatial base constraints may be sufficient. Thus, in some implementations, for CBSR, spatial base constraints, rather than frequency base constraints, may be provided to the UE by the base station. Therefore, for some combinations of (N1, N2), frequency base constraints may be supported, and the configuration of frequency base constraints may be at least partially based on the values ​​of (N1, N2).

[0146] Configure the number of frequency bases used to enhance Type II CSI reporting.

[0147] As mentioned earlier, in some implementations, the frequency base can be beam-specific. For example, a frequency base can be considered for different polarizations and different spatial beams. Figure 13 A diagram of an exemplary precoder structure with frequency compression according to some implementation schemes is shown. Figure 13 The formula in the text represents the use of the first... The layer's aggregated precoding vector. Figure 13 In the exemplary configuration shown, each polarization has L spatial bases (or beams), where L = 2, and the spatial bases (for each polarization) are represented by v0 and v1. Figure 13As shown, v0 represents the first spatial beam (or spatial basis) in the first polarization having a corresponding number M0 frequency bases. The second spatial beam (or spatial basis) v1 in the first polarization may have a smaller corresponding number M1 frequency bases. Similarly, v0 in the second polarization has a corresponding number M2 frequency bases and v1 in the second polarization has a corresponding number M3 frequency bases. That is, M0 represents the number of frequency bases corresponding to v0 in the first polarization, M1 represents the number of frequency bases corresponding to v1 in the first polarization, M2 represents the number of frequency bases corresponding to v0 in the second polarization, and M3 represents the number of frequency bases corresponding to v1 in the second polarization. When determining the corresponding values ​​of M0, M1, M2, and M3, the value of M is obtained, and the value of M corresponds to the (horizontal) dimension of the W2 matrix. Therefore, M (or the value of M) also represents W f The total number of frequency bases (or vertical dimensions) of the matrix. N3 (or the value of N3) represents the number of frequency units (e.g., the number of PMI subbands).

[0148] For each i-th spatial basis, the corresponding combination coefficient is the corresponding quantity M. i A linear combination of frequency bases. M i The value can be selected by the UE and reported in the CSI, or the value can be configured in the UE by the base station via higher-layer (e.g., RRC) signaling. In some implementations, known as explicit configuration, the base station can configure the value in the UE via dedicated radio resource control (RRC) signaling. For example, the UE can explicitly obtain the value from the base station via dedicated higher-layer (e.g., RRC) signaling. i The value of . In some implementations, known as implicit configuration, this value can be derived by the UE from some other RRC parameters based on specified predefined rules.

[0149] In the first specific implementation, M i The value of M can be a function of the number of ports in two dimensions (vertical and horizontal). That is, M i The value of can be a function of (N1, N2). Large values ​​of N1 and N2 (e.g., equal to or greater than eight) can result in a narrower spatial beam and therefore a smaller M. i The value is sufficient.

[0150] In the second specific implementation, the frequency dimension can be considered. Here, the UE may need to report a large number of sub-bands. i The value of M can be a function of N3. A large N3 value can lead to a more distinguishable path, therefore a large M... i The value can be preferred. For example, M i =f2(N3).

[0151] In the third specific implementation, both spatial and frequency factors can be considered. In this case, M iThe value of can be a function of (N1, N2, N3), and spatial-temporal granularity can be considered together. For example, M i =f3(max(N1,N2),N3).

[0152] Configure the PMI frequency compression unit for enhancing NR Type II CSI.

[0153] Refer again Figure 10 One could consider determining the length of the frequency base. In fact, this leads to determining how to choose W. f The dimensions of the matrix. It should be noted that there is an explicit relationship between the frequency domain and the time domain (Fourier transform), which allows the use of the Fast Fourier Transform (FFT). For example, if the UE needs to report CSI for a specified number (e.g., five) of subbands, then W... f The columns can have the same number of entries (five in this example). The value for each sub-band is available. In the proposed system, the number of resource blocks (RBs) can range from 1 to 275 (as an example of a wider range). Therefore, FFT can be supported for this range. For W... f The dimension allows for the establishment of a relationship / link between the number of CSI frequency units and the FFT size.

[0154] W f The frequency basis in the vector can be a subset of the DFT vector. Therefore, the dimension of the frequency basis can be equal to the number of CSI frequency cells (e.g., the number of subbands as indicated in the CSI report bands). According to the current 3GPP specification, the number of subbands can be any integer within a specified range (e.g., from 1 to 19). For finer PMI frequency cells, the dimension of the frequency basis can vary over a much wider range (e.g., from 1 to hundreds). As mentioned above, frequency compression can be achieved via FFT. To facilitate implementation, the dimension of the frequency basis (e.g., the FFT size) can be carefully chosen.

[0155] Figure 14 An exemplary architecture of a wireless communication system 1400 according to an embodiment disclosed herein is shown. The description provided below is for an exemplary wireless communication system 1400 operating in conjunction with LTE system standards and / or 5G or NR system standards provided by 3GPP technical specifications.

[0156] like Figure 14 As shown, the wireless communication system 1400 includes UE 1402 and UE 1404 (but any number of UEs may be used). In this example, UE 1402 and UE 1404 are shown as smartphones (e.g., handheld touchscreen mobile computing devices capable of connecting to one or more cellular networks), but may also include any mobile or non-mobile computing device configured for wireless communication.

[0157] UE 1402 and UE 1404 can be configured to communicatively couple with RAN 1406. In an implementation, RAN 1406 can be NG-RAN, E-UTRAN, etc. UE 1402 and UE 1404 utilize connections (or channels) with RAN 1406 (shown as connection 1408 and connection 1410, respectively), where each connection (or channel) includes a physical communication interface. RAN 1406 may include one or more base stations, such as base station 1412 and base station 1414, implementing connection 1408 and connection 1410.

[0158] In this example, Connection 1408 and Connection 1410 are air interfaces that enable this type of communication coupling and can conform to the RAT used by RAN 1406, such as LTE and / or NR, for example.

[0159] In some implementations, UE 1402 and UE 1404 may also exchange communication data directly via sidelink interface 1416. UE 1404 is shown configured to access an access point (shown as AP 1418) via connection 1420. For example, connection 1420 may include a local wireless connection, such as a connection conforming to any IEEE 802.11 protocol, where AP 1418 may include... Router. In this example, AP 1418 can connect to another network (e.g., the Internet) without going through CN 1424.

[0160] In the implementation, UE 1402 and UE 1404 may be configured to communicate with each other or with base station 1412 and / or base station 1414 on a multi-carrier communication channel using orthogonal frequency division multiplexing (OFDM) communication signals according to various communication technologies, such as but not limited to orthogonal frequency division multiple access (OFDMA) communication technology (e.g., for downlink communication) or single-carrier frequency division multiple access (SC-FDMA) communication technology (e.g., for uplink and ProSe or sidelink communication)). However, the scope of the implementation is not limited in this respect. The OFDM signal may include multiple orthogonal subcarriers.

[0161] In some implementations, all or part of base station 1412 or base station 1414 may be implemented as one or more software entities running on a server computer as part of a virtual network. Furthermore, or in other implementations, base station 1412 or base station 1414 may be configured to communicate with each other via interface 1422. In implementations where wireless communication system 1400 is an LTE system (e.g., when CN 1424 is an EPC), interface 1422 may be an X2 interface. This X2 interface may be defined between two or more base stations (e.g., two or more eNBs, etc.) connected to the EPC and / or between two eNBs connected to the EPC. In implementations where wireless communication system 1400 is an NR system (e.g., when CN 1424 is a 5GC), interface 1422 may be an Xn interface. This Xn interface is defined between two or more base stations (e.g., two or more gNBs, etc.) connected to the 5GC, between base station 1412 (e.g., a gNB) and eNBs connected to the 5GC, and / or between two eNBs connected to the 5GC (e.g., CN 1424).

[0162] RAN 1406 is shown communicatively coupled to CN 1424. CN 1424 may include one or more network elements 1426 configured to provide various data and telecommunications services to customers / subscribers (e.g., users of UE 1402 and UE 1404) connected to CN 1424 via RAN 1406. Components of CN 1424 may be implemented in a single physical device or a separate physical device, including components for reading and executing instructions from machine-readable or computer-readable media (e.g., non-transitory machine-readable storage media).

[0163] In this implementation, CN 1424 may be an EPC, and RAN 1406 may be connected to CN 1424 via S1 interface 1428. In this implementation, S1 interface 1428 may be divided into two parts: an S1 user plane (S1-U) interface, which carries traffic data between base station 1412 or base station 1414 and the service gateway (S-GW); and an S1-MME interface, which is the signaling interface between base station 1412 or base station 1414 and the mobility management entity (MME).

[0164] In this implementation, CN 1424 may be a 5GC, and RAN 1406 may be connected to CN 1424 via NG interface 1428. In this implementation, NG interface 1428 may be divided into two parts: an NG user plane (NG-U) interface, which carries traffic data between base station 1412 or 1414 and the User Plane Function (UPF); and an S1 control plane (NG-C) interface, which is the signaling interface between base station 1412 or 1414 and the Access and Mobility Management Function (AMF).

[0165] Generally, application server 1430 may be an element providing Internet Protocol (IP) carried resources (e.g., packet-switched data services) for use with CN 1424. Application server 1430 may also be configured to support one or more communication services (e.g., VoIP sessions, group communication sessions, etc.) for UE 1402 and UE 1404 via CN 1424. Application server 1430 may communicate with CN 1424 via IP communication interface 1432.

[0166] Figure 15 A system 1500 for performing signaling 1534 between a wireless device 1502 and a network device 1518 according to an embodiment disclosed herein is shown. System 1500 may be part of a wireless communication system as described herein. Wireless device 1502 may be, for example, a UE (User Equipment) of a wireless communication system. Network device 1518 may be, for example, a base station (e.g., an eNB or gNB) of a wireless communication system.

[0167] Wireless device 1502 may include one or more processors 1504. Processor 1504 may execute instructions to cause various operations of wireless device 1502 to be performed as described herein. Processor 1504 may include one or more baseband processors, which may be implemented using, for example, a central processing unit (CPU), digital signal processor (DSP), application-specific integrated circuit (ASIC), controller, field-programmable gate array (FPGA) device, another hardware device, firmware device, or any combination thereof configured to perform the operations described herein.

[0168] Wireless device 1502 may include memory 1506. Memory 1506 may be a non-transitory computer-readable storage medium that stores instructions 1508 (which may include, for example, instructions executed by processor 1504). Instructions 1508 may also be referred to as program code or computer program. Memory 1506 may also store data used by processor 1504 and results calculated by the processor.

[0169] Wireless device 1502 may include one or more transceivers 1510, which may include radio frequency (RF) transmitter and / or receiver circuitry that uses antenna 1512 of wireless device 1502 to facilitate signaling (e.g., signaling 1534) to and / or from wireless device 1502 and other devices (e.g., network device 1518) according to a corresponding RAT.

[0170] Wireless device 1502 may include one or more antennas 1512 (e.g., one, two, four, or more). In embodiments with multiple antennas 1512, wireless device 1502 may utilize spatial diversity of such multiple antennas 1512 to transmit and / or receive multiple different data streams on the same time-frequency resource. This practice may be referred to, for example, as a multiple-input multiple-output (MIMO) approach (referring to multiple antennas used separately on the transmitting and receiving sides to implement this aspect). MIMO transmissions performed by wireless device 1502 may be achieved according to precoding (or digital beamforming) applied to wireless device 1502, which multiplexes data streams across antennas 1512 based on known or assumed channel characteristics, such that each data stream is received with appropriate signal strength relative to the others at a desired location in the spatial domain (e.g., the location of the receiver associated with that data stream). Some implementations may use a single-user MIMO (SU-MIMO) method (where the entire data stream is directed to a single receiver) and / or a multi-user MIMO (MU-MIMO) method (where individual data streams may be directed to individual (different) receivers at different locations in the airspace).

[0171] In some implementations with multiple antennas, the wireless device 1502 can implement analog beamforming technology, whereby the phase of the signal transmitted by the antenna 1512 is relatively adjusted, enabling (joint) transmission of the directional antenna 1512 (this is sometimes referred to as beam control).

[0172] Wireless device 1502 may include one or more interfaces 1514. Interface 1514 can be used to provide input to or output to wireless device 1502. For example, wireless device 1502 as a UE may include interface 1514, such as a microphone, speaker, touchscreen, button, etc., to allow users of the UE to input to and / or output to the UE. Other interfaces of such a UE may consist of transmitters, receivers, and other circuitry (e.g., other than the transceiver 1510 / antenna 1512 already described) that allow communication between the UE and other devices, and may be based on known protocols (e.g., (etc.) to perform the operation.

[0173] Wireless device 1502 may include a port selection codebook module 1516. The port selection codebook module 1516 may be implemented via hardware, software, or a combination thereof. For example, the port selection codebook module 1516 may be implemented as a processor, circuitry, and / or instructions 1508 stored in memory 1506 and executed by processor 1504. In some examples, the port selection codebook module 1516 may be integrated within processor 1504 and / or transceiver 1510. For example, the port selection codebook module 1516 may be implemented via a combination of software components (e.g., executed by a DSP or general-purpose processor) and hardware components (e.g., logic gates and circuitry) within processor 1504 or transceiver 1510.

[0174] The port selection codebook module 1516 can be used in various aspects of this disclosure. For example, the port selection codebook module 1516 can be configured to perform... Figure 4 Method 400 and / or shown Figure 5 Method 500 is shown.

[0175] Network device 1518 may include one or more processors 1520. Processor 1520 may execute instructions to cause various operations of network device 1518 to be performed as described herein. Processor 1504 may include one or more baseband processors, which may be implemented using, for example, a CPU, DSP, ASIC, controller, FPGA device, another hardware device, firmware device, or any combination thereof configured to perform the operations described herein.

[0176] Network device 1518 may include memory 1522. Memory 1522 may be a non-transitory computer-readable storage medium that stores instructions 1524 (which may include, for example, instructions executed by processor 1520). Instructions 1524 may also be referred to as program code or computer program. Memory 1522 may also store data used by processor 1520 and results calculated by the processor.

[0177] Network device 1518 may include one or more transceivers 1526, which may include RF transmitter and / or receiver circuitry that uses the antenna 1528 of network device 1518 to facilitate signaling (e.g., signaling 1534) to and / or from network device 1518 and other devices (e.g., wireless device 1502) according to the corresponding RAT.

[0178] Network device 1518 may include one or more antennas 1528 (e.g., one, two, four or more). In embodiments with multiple antennas 1528, network device 1518 may perform MIMO, digital beamforming, analog beamforming, beam control, etc., as described above.

[0179] Network device 1518 may include one or more interfaces 1530. Interface 1530 can be used to provide input to or output to network device 1518. For example, network device 1518 as a base station may include interface 1530 consisting of transmitters, receivers, and other circuitry (e.g., in addition to the transceiver 1526 / antenna 1528 already described), enabling the base station to communicate with other equipment in the core network, and / or enabling the base station to communicate with external networks, computers, databases, etc., for the purpose of performing operations, management, and maintenance of the base station or other equipment operatively connected to the base station.

[0180] Network device 1518 may include a port selection codebook module 1532. The port selection codebook module 1532 may be implemented via hardware, software, or a combination thereof. For example, the port selection codebook module 1532 may be implemented as a processor, circuitry, and / or instructions 1524 stored in memory 1522 and executed by processor 1520. In some examples, the port selection codebook module 1532 may be integrated within processor 1520 and / or transceiver 1526. For example, the port selection codebook module 1532 may be implemented via a combination of software components (e.g., executed by a DSP or general-purpose processor) and hardware components (e.g., logic gates and circuitry) within processor 1520 or transceiver 1526.

[0181] The port selection codebook module 1532 can be used in various aspects of this disclosure. For example, the port selection codebook module 1532 can be configured to perform... Figure 6 Method 600 is shown.

[0182] For one or more embodiments, at least one of the components shown in one or more of the foregoing figures may be configured to perform one or more operations, techniques, processes, and / or methods as described herein. For example, the baseband processor described herein in conjunction with one or more of the foregoing figures may be configured to operate according to one or more examples of the examples described herein. Similarly, the circuitry associated with the UE, base station, network element, etc., described above in conjunction with one or more of the foregoing figures may be configured to operate according to one or more examples of the examples shown herein.

[0183] Unless otherwise expressly stated, any of the above embodiments may be combined with any other embodiment (or combination of embodiments). The foregoing description of one or more specific embodiments provides illustration and description, but is not intended to be exhaustive or to limit the scope of the embodiments to the precise form disclosed. In view of the teachings above, modifications and variations are possible, or modifications and variations may be derived from practice of various embodiments.

[0184] Implementations and specific embodiments of the systems and methods described herein may include various operations embodied in machine-executable instructions to be executed by a computer system. The computer system may include one or more general-purpose or special-purpose computers (or other electronic devices). The computer system may include hardware components, including specific logical components for performing the operations, or may include a combination of hardware, software, and / or firmware.

[0185] It should be recognized that the systems described herein include descriptions of specific implementations. These implementations may be combined into a single system, partially integrated into other systems, divided into multiple systems, or otherwise partitioned or combined. Furthermore, it is conceivable to use parameters, attributes, aspects, etc., of one implementation in another implementation. For clarity, these parameters, attributes, aspects, etc., are described only in one or more implementations, and it should be recognized that unless specifically stated herein, these parameters, attributes, aspects, etc., may be combined with or substituted for parameters, attributes, aspects, etc., of another implementation.

[0186] As is widely recognized, the use of personally identifiable information should comply with privacy policies and practices that are generally accepted to meet or exceed industry or governmental requirements for protecting user privacy. Specifically, personally identifiable information data should be managed and processed to minimize the risk of unintentional or unauthorized access or use, and the nature of authorized use should be clearly explained to users.

[0187] Although the foregoing has been described in considerable detail for clarity, it will be apparent that certain changes and modifications can be made without departing from the principles of the invention. It should be noted that many alternative ways exist to implement both the processes and apparatus described herein. Therefore, embodiments of the invention should be considered illustrative rather than restrictive, and this specification is not limited to the details given herein, but can be modified within the scope of the appended claims and their equivalents.

Claims

1. A method for a user equipment (UE), the method comprising: At the UE, the Channel State Information (CSI) Report Configuration (CSI-ReportConfig) from the base station is decoded, wherein the CSI-ReportConfig indicates at most L CSI-RS ports that the UE can select from P CSI Reference Signal (CSI-RS) ports configured for measuring and reporting CSI. At the UE, a CSI-RS port selected from the P CSI-RS ports is determined, wherein the selected CSI-RS port includes the L CSI-RS ports or fewer CSI-RS ports; At the UE, a port selection matrix W1 is generated corresponding to the CSI-RS ports selected from the P CSI-RS ports, wherein the port selection matrix W1 is generated by... Given, among which and Each is a P / 2×L matrix, where in or In each of the L columns, only one entry is 1 and all other entries are 0. or Different columns in the array cannot be the same, and the first P / 2 CSI-RS ports are horizontally polarized H-poles and the last P / 2 CSI-RS ports are vertically polarized V-poles. and different; as well as The port selection matrix W1 is transmitted from the UE to the base station.

2. The method of claim 1, wherein the UE selects the L CSI-RS ports from the P / 2 CSI-RS ports, and wherein transmitting the port selection matrix W1 includes using a bit width of 2× log2(C(P / 2,L)) , where C is a combinatorial function.

3. The method of claim 1, wherein the UE selects fewer than or equal to the L CSI-RS ports from the P / 2 CSI-RS ports, and wherein transmitting the port selection matrix W1 includes using a bit width , where C is a combinatorial function.

4. The method of claim 1, wherein the CSI-ReportConfig is configured for more than one CSI-RS resource for Channel Measurement Resource (CMR), wherein the total number of CSI-RS ports is the union of all ports in all CSI-RS resources configured in the CSI-ReportConfig, and wherein the CSI-RS port index is based on the CSI-RS resource identifier ID.

5. The method of claim 1, wherein the CSI-ReportConfig configures more than one CSI-RS resource for Channel Measurement Resource (CMR), and the method further comprises: The CSI-RS resource identifier ID selected in the report; as well as The report describes the port selection configured in the chosen CSI-RS resource ID.

6. The method of claim 1, wherein the port selection matrix W1 is layer-independent, and wherein transmitting the port selection matrix W1 includes independently reporting as ,in This is a layer index.

7. The method of claim 1, wherein the port selection matrix W1 is layer-common, and wherein transmitting the port selection matrix W1 includes reporting a single port selection matrix for all layers.

8. The method of claim 1, wherein the port selection matrix W1 is subband independent, and wherein transmitting the port selection matrix W1 includes independently reporting as ,in n This is the sub-band index.

9. The method of claim 1, wherein the port selection matrix W1 is subband common, and wherein transmitting the port selection matrix W1 includes reporting a single port selection matrix for all subbands.

10. The method of claim 1, wherein the CSI-ReportConfig further configures the UE to select a subset of frequency bases, the method further comprising: Determine the selected frequency basis subset; Generate a frequency basis selection matrix W corresponding to the selected frequency basis subset. f The precoding matrix index PMI matrix W = W1W2W f , where W2 is a matrix including the compression combination coefficients; as well as The frequency basis selection matrix W f The report was sent to the base station.

11. The method of claim 10, wherein the total number of PMI subbands used for frequency base selection is N. CQISubband R, where N CQISubband R is the number of Channel Quality Indicator (CQI) subbands configured by the base station, and R is the size of the CQI subband divided by the size of the PMI subband.

12. The method of claim 10, wherein the CSI-ReportConfig configures the UE for at least one of a Broadband Channel Quality Indicator (CQI) report and a Broadband PMI report.

13. The method of claim 10, wherein the CSI-ReportConfig configures the UE to select a DC frequency base and any Mv-1 frequency bases from the N-1 frequency bases and uses a bit width log2(C(N-1, Mv-1)) To report the frequency basis selection matrix W f .

14. The method of claim 10, wherein the CSI-ReportConfig configures the UE to select one of D possible selections of a DC frequency base and Mv-1 frequency bases out of N-1 frequency bases.

15. The method of claim 10, wherein the CSI-ReportConfig includes window constraint selection of the frequency base subset, wherein the UE is constrained to be a consecutive k-value from N frequency bases. Mv frequency bases are selected, where k is an integer and k Mv <N。 16. The method of claim 15, further comprising: The continuous k The locations of Mv frequency bases are reported to the base station.

17. The method of claim 15, wherein the base station is configured with the continuous k The positions of Mv frequency bases.

18. The method of claim 10, wherein the CSI-ReportConfig includes a list of frequency base subsets, wherein each entry in the list is configured with a different frequency base subset for the UE to select.

19. A method for a base station, the method comprising: At the base station, a Channel State Information (CSI) Report Configuration (CSI-ReportConfig) for a User Equipment (UE) is generated. The CSI-ReportConfig indicates at most L CSI-RS ports that the UE can select from P CSI Reference Signal (CSI-RS) ports configured for measuring and reporting CSI. The CSI-ReportConfig further indicates a subset of frequency bases that the UE can select. The base station receives a port selection matrix W1 from the UE corresponding to the CSI-RS ports selected from the P CSI-RS ports; The base station receives a matrix W2, including compression combination coefficients, from the UE. At the base station, a frequency basis selection matrix W corresponding to the selected frequency basis subset is received. f ; At the base station, the precoding matrix index (PMI) matrix W=W1 is determined. W2 W f The port selection matrix W1 is composed of Given, among which and Each is a P / 2×L matrix, where in or In each of the L columns, only one entry is 1 and all other entries are 0. or Different columns in the array cannot be the same, and the first P / 2 CSI-RS ports are horizontally polarized H-poles and the last P / 2 CSI-RS ports are vertically polarized V-poles. and different; as well as At the base station, the PMI matrix W is used to generate the Physical Downlink Shared Channel (PDSCH) demodulation reference signal (DMRS) for transmission of the UE.

20. The method of claim 19, wherein the total number of PMI subbands used for frequency base selection is N. CQISubband R, where N CQISubband R is the number of Channel Quality Indicator (CQI) subbands configured by the base station, and R is the size of the CQI subband divided by the size of the PMI subband.

21. The method of claim 19, further comprising: The UE is configured for use in at least one of the Broadband Channel Quality Indicator (CQI) report and the Broadband PMI report.

22. The method of claim 19, further comprising: The UE is configured to select a DC frequency base and any Mv-1 frequency base from N-1 frequency bases and use a bit width. log2(C(N-1, Mv-1)) To report the frequency basis selection matrix W f .

23. The method of claim 19, further comprising: The UE is configured to select one of D possible choices from the DC frequency base and the Mv-1 frequency bases out of N-1 frequency bases.

24. The method of claim 19, further comprising: Configure the window constraint selection of the frequency basis subset, wherein the UE is constrained to be a consecutive k-value from N frequency bases. Mv frequency bases are selected, where k is an integer and k Mv <N。 25. The method of claim 24, further comprising: The base station receives the consecutive k from the UE. Indication of the positions of Mv frequency bases.

26. The method of claim 24, further comprising: Configure the continuous k for the UE The positions of Mv frequency bases.

27. The method of claim 19, wherein the CSI-ReportConfig includes a list of frequency base subsets, wherein each entry in the list is configured with a different frequency base subset for the UE to select.

28. A computer program product comprising instructions that, when executed by a processor, perform the steps of the method according to any one of claims 1 to 27.

29. An apparatus comprising components for carrying out the steps of the method according to any one of claims 1 to 27.

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