Configuration of intermediate set size for frequency domain basis reporting
Certain aspects of the present disclosure provide techniques for channel state information (CSI) reporting with frequency domain (FD) compression. A method that can be performed by a user equipment (UE) includes determining the size of the intermediate set based on one or more parameters included in the CSI report configuration, determining one or more FD bases for each layer based on the intermediate set, wherein the one or more FD bases are characterized by an M value indicative of a number of the one or more FD bases and based on the CSI report configuration, and reporting the one or more FD bases for each layer based on the size of the intermediate set.
1 . A method for communication by a user equipment (UE) in a wireless network, comprising:
receiving, from a base station, channel state information (CSI) report configuration, configuring the UE for reporting frequency domain (FD) basis information including one or more parameters for calculating a size corresponding to an intermediate set of a plurality of frequency domain (FD) bases, wherein the intermediate set is common to all layers of a first rank, and the intermediate set is a subset of the plurality of FD bases;
determining the size of the intermediate set based on one or more parameters included in the CSI report configuration and based on a maximum M value across all layers for a particular rank, wherein determining the size of the intermediate set further comprises scaling the maximum M value across all layers for the particular rank by a first scaling factor α to determine a first value;
determining one or more FD bases for each layer according to the size of the intermediate set, wherein the one or more FD bases are characterized by an M value indicative of a number of the one or more FD bases and based on the CSI report configuration; and
transmitting, to the base station, an indication of the one or more FD bases for each layer based on the size of the intermediate set.
2 . The method of claim 1 , wherein a is uniquely configured, derived, or specified for each rank.
3 . The method of claim 1 , wherein the M value is indicative of at least one M value for one layer different from other M values for other layers.
4 . The method of claim 1 , further comprising determining the M value based on a total number of FD bases and a number of Precoding Matrix Indicator (PMI) subbands within a Channel Quality Indicator (CQI) subband, wherein the total number of FD bases is determined based on network configuration, and the number of PMI subbands within a CQI subband is network configured.
5 . The method of claim 1 , wherein the first value is determined as the size of the intermediate set.
6 . The method of claim 1 , wherein the one or more parameters are configured by the base station.
7 . A method for communication by a user equipment (UE) in a wireless network, comprising:
receiving, from a base station, channel state information (CSI) report configuration, configuring the UE for reporting frequency domain (FD) basis information including one or more parameters for calculating a size corresponding to an intermediate set of a plurality of frequency domain (FD) bases, wherein the intermediate set is common to all layers of a first rank, and the intermediate set is a subset of the plurality of FD bases;
determining the size of the intermediate set based on one or more parameters included in the CSI report configuration;
determining one or more FD bases for each layer according to the size of the intermediate set, wherein the one or more FD bases are characterized by an M value indicative of a number of the one or more FD bases, wherein the M value is based on a total number of FD bases and a number of Precoding Matrix Indicator (PMI) subbands within a Channel Quality Indicator (CQI) subband, wherein the total number of FD bases is based on network configuration, and the number of PMI subbands within a CQI subband is network configured; and
transmitting, to the base station, an indication of the one or more FD bases for each layer based on the size of the intermediate set.
8 . The method of claim 7 , wherein the one or more parameters are configured by the base station.
9 . A user equipment (UE), comprising:
one or more memories; and
at least one processor coupled to the one or more memories, the at least one processor and the one or more memories configured to cause the UE to:
receive, from a base station, channel state information (CSI) report configuration, configuring the UE for reporting frequency domain (FD) basis information including one or more parameters for calculating a size corresponding to an intermediate set of a plurality of frequency domain (FD) bases, wherein the intermediate set is common to all layers of a first rank, and the intermediate set is a subset of the plurality of FD bases;
determine the size of the intermediate set based on one or more parameters included in the CSI report configuration and based on a maximum M value across all layers for a particular rank, wherein to determine the size of the intermediate set, the at least one processor and the one or more memories cause the UE to scale the maximum M value across all layers for the particular rank by a first scaling factor α to determine a first value;
determine one or more FD bases for each layer according to the size of the intermediate set, wherein the one or more FD bases are characterized by an M value indicative of a number of the one or more FD bases and based on the CSI report configuration; and
transmit, to the base station, an indication of the one or more FD bases for each layer based on the size of the intermediate set.
10 . The UE of claim 9 , wherein α is uniquely configured, derived, or specified for each rank.
11 . The UE of claim 9 , wherein the M value is indicative of at least one M value for one layer different from other M values for other layers.
12 . The UE of claim 9 , wherein the at least one processor and the one or more memories are further configured to cause the UE to:
determine the M value based on a total number of FD bases and a number of Precoding Matrix Indicator (PMI) subbands within a Channel Quality Indicator (CQI) subband, wherein the total number of FD bases is determined based on network configuration, and the number of PMI subbands within a CQI subband is network configured.
13 . The UE of claim 9 , wherein the first value is determined as the size of the intermediate set.
14 . The UE of claim 9 , wherein the one or more parameters are configured by the base station.