Type II CSI reporting for CJT with angle and delay reciprocity
Systems and methods are disclosed herein for Channel State Information (CSI) reporting with angle and delay reciprocity. Embodiments of a User Equipment (UE) and a method of operation thereof are disclosed. Embodiments of network node and a method of operation thereof are also disclosed.
1 . A method performed by a User Equipment (UE), the method comprising the following steps:
receiving, from a network node, information for a Channel State Information (CSI) reporting configuration that configures the UE with:
multiple Non-Zero Power (NZP) CSI Reference Signal (CSI-RS) resources for channel measurement associated with the CSI reporting configuration, where each of the multiple NZP CSI-RS resources is associated with a different Transmission Configuration Indicator (TCI) state or unified TCI state; and
a parameter combination indicating at least a total number of Frequency Domain (FD) basis vectors to be selected across the multiple NZP CSI-RS resources or a plurality of sets of CSI-RS ports;
performing channel measurement on:
the configured multiple NZP CSI-RS resources according to the respective TCI state or unified TCI state;
receiving, from the network node, information that configures the UE with one or more FD basis vector windows that are over all configured NZP CSI-RS resources, in the case of configuration of multiple NZP CSI-RS resources for channel measurement;
receiving, from the network node, information that configures the UE with a number of FD basis vectors to be selected, where the number of FD basis vectors to be selected is common to all configured NZP CSI-RS resources, in the case of configuration of multiple NZP CSI-RS resources for channel measurement;
computing CSI based on the channel measurements and in accordance with the received information that configures the UE with the one or more frequency domain basis vector windows and the information that configures the UE with the number of FD basis vectors to be selected; and
reporting the computed CSI.
2 . The method of claim 1 , wherein:
the UE is configured with multiple(S) NZP CSI-RS resources for channel measurement; and
the one or more frequency domain basis vector windows comprise a single FD basis window that is applicable for all S configured NZP CSI-RS resources.
3 . The method of claim 2 , wherein the information that configures the UE with the single FD basis window comprises an index (M_init) of a starting FD basis vector in the single FD basis window and a window size N, where N is a number of consecutive FD basis vectors in the single FD basis window.
4 . The method of claim 3 , wherein the starting FD basis vector index for the single FD basis window is predefined.
5 . The method of claim 2 , wherein a common subset of FD basis vectors is selected for all S configured NZP CSI-RS resources from the single FD basis window.
6 . The method of claim 5 , wherein the UE reports the selected common subset of FD basis vectors as part of the CSI via a combinatorial coefficient index.
7 . The method of claim 5 , wherein the UE performs further down-selection among the selected common subset of FD basis vectors and the further down-selected FD basis vectors are reported in the CSI via a non-zero coefficient bitmap.
8 . The method of claim 1 , wherein for each of the multiple(S) configured NZP CSI-RS resources, the corresponding selected FD basis vectors are phase rotated such that a zero-th FD basis vector is always selected, wherein the rotated phase is reported as part of the CSI.
9 . A User Equipment (UE) comprising
one or more transmitters;
one or more receivers; and
processing circuitry associated with the one or more transmitters and the one or more receivers, the processing circuitry configured to cause the UE to perform one or more of the following:
receiving, from a network node, information for a Channel State Information (CSI) reporting configuration that configures the UE with:
multiple Non-Zero Power (NZP) CSI Reference Signal (CSI-RS) resources for channel measurement associated with a CSI reporting configuration, where each of the multiple NZP CSI-RS resources is associated with a different Transmission Configuration Indicator (TCI) state or unified TCI state; and
a parameter combination indicating at least a total number of Frequency Domain (FD) basis vectors to be selected across the multiple NZP CSI-RS resources or a plurality of sets of CSI-RS ports;
performing channel measurement on:
the configured multiple NZP CSI-RS resources according to the respective TCI state or unified TCI state;
receiving, from the network node, information that configures the UE with one or more FD basis vector windows that are over all configured NZP CSI-RS resources, in the case of configuration of multiple NZP CSI-RS resources for channel measurement;
receiving, from the network node, information that configures the UE with a number of FD basis vectors to be selected, where the number of FD basis vectors to be selected is common to all configured NZP CSI-RS resources, in the case of configuration of multiple NZP CSI-RS resources for channel measurement;
computing CSI based on the channel measurements and in accordance with the received information that configures the UE with the one or more FD basis vector windows and the information that configures the UE with the number of FD basis vectors to be selected; and
reporting the computed CSI.
10 . The UE of claim 9 , wherein:
the UE is configured with multiple(S) NZP CSI-RS resources for channel measurement; and
the one or more FD basis vector windows comprise a single FD basis window that is applicable for all S configured NZP CSI-RS resources.
11 . The UE of claim 10 , wherein the information that configures the UE with the single FD basis window comprises an index (M_init) of a starting FD basis vector in the single FD basis window and a window size N, where N is a number of consecutive FD basis vectors in the single FD basis window.
12 . The UE of claim 11 , wherein the starting FD basis vector index for the single FD basis window is predefined.
13 . The UE of claim 10 , wherein a common subset of FD basis vectors is selected for all S configured NZP CSI-RS resources from the single FD basis window.
14 . The UE of claim 13 , wherein the UE reports the selected common subset of FD basis vectors as part of the CSI via a combinatorial coefficient index.
15 . The UE of claim 13 , wherein the UE performs further down-selection among the selected common subset of FD basis vectors and the further down-selected FD basis vectors are reported in the CSI via a non-zero coefficient bitmap.
16 . The UE of claim 9 , wherein for each of the multiple(S) configured NZP CSI-RS resources, the corresponding selected FD basis vectors are phase rotated such that a zero-th FD basis vector is always selected, wherein the rotated phase is reported as part of the CSI.
17 . A method performed by a network node, the method comprising:
transmitting, to a User Equipment (UE), information that configures the UE with:
multiple Non-Zero Power (NZP) Channel State Information (CSI) Reference Signal (CSI-RS) resources for channel measurement associated with a CSI reporting configuration, where each of the multiple NZP CSI-RS resources is associated with a different Transmission Configuration Indicator (TCI) state or unified TCI state;
transmitting, to the UE, information that configures the UE with one or more Frequency Domain (FD) basis vector windows that are: over all configured NZP CSI-RS resources, in the case of configuration of multiple NZP CSI-RS resources for channel measurement;
transmitting, to the UE, information that configures the UE with a number of FD basis vectors to be selected, where the number of FD basis vectors to be selected is:
common to all configured NZP CSI-RS resources, in the case of configuration of multiple NZP CSI-RS resources for channel measurement; and
receiving, from the UE, CSI in accordance with the transmitted information that configures the UE with the one or more FD basis vector windows and the transmitted information that configures the UE with the number of FD basis vectors to be selected.