CODE BOOK SUBSET RESTRICTION FOR CJT OVER MULTIPLE TRPs

A User Equipment (UE), comprising:

• a communication interface comprising a transmitter and a receiver;
• and
• processing circuitry associated with the communication interface, the processing circuitry configured to cause the UE to:
• receive, from a network node, configuration information that configures the UE with a plurality of Non-Zero Power (NZP) Channel State Information Reference Signal (CSI-RS) resources each with 2N1N2 CSI-RS antenna ports, for Coherent Joint Transmission (CJT) Channel State Information (CSI) feedback, wherein N1 and N2 are positive integers;
• receive, from the network node, codebook subset restriction (CBSR) information for one or more of the plurality of NZP CSI-RS resources that configures the UE with amplitude restrictions for a subset of spatial vectors or beams on a per NZP CSI-RS resource basis;
• and
• report, to the network node, CSI based on the configuration information and the CBSR information, wherein the CSI comprises:
• information about a number of layers and a subset of the plurality of NZP CSI-RS resources;
• and
• for each of the subset of the plurality of NZP CSI-RS resources, information for one or more selected spatial domain (SD) basis vectors or beams;
• and
• for each of the number of layers, one or more selected frequency domain (FD) basis vectors, and a set of normalized coefficients each associated to one of the one or more selected SD basis vectors or beams and one of the one or more selected FD basis vectors or beams for each antenna polarization, wherein the one or more selected SD basis vectors or beams are either unrestricted beams or satisfy the amplitude restrictions.

A method performed by a network node, the method comprising:

• sending, to a User Equipment (UE) configuration information that configures the UE with a plurality of Non-Zero Power (NZP) Channel State Information Reference Signal (CSI-RS) resources each with 2N1N2 CSI-RS antenna ports, for Coherent Joint Transmission (CJT) Channel State Information (CSI) feedback, wherein N1 and N2 are positive integers;
• sending, to the UE, codebook subset restriction (CBSR) information for one or more of the plurality of NZP CSI-RS resources that configures the UE with amplitude restrictions for a subset of spatial vectors or beams on a per NZP CSI-RS resource basis;
• and
• receiving, from the UE, CSI based on the configuration information and the CBSR information, wherein the CSI comprises:
• information about a number of layers and a subset of the plurality of NZP CSI-RS resources;
• and
• for each of the subset of the plurality of NZP CSI-RS resources, information for one or more selected spatial domain (SD) basis vectors or beams;
• and
• for each of the number of layers, one or more selected frequency domain (FD) basis vectors, and a set of normalized coefficients each associated to one of the one or more selected SD basis vectors or beams and one of the one or more selected FD basis vectors or beams for each antenna polarization, wherein the one or more selected SD basis vectors or beams are either unrestricted beams or satisfy the amplitude restrictions.

A network node comprising:

• a communication interface;
• and
• processing circuitry associated with the communication interface, the processing circuitry configured to cause the network node to:
• send, to a User Equipment (UE) configuration information that configures the UE with a plurality of Non-Zero Power (NZP) Channel State Information Reference Signal (CSI-RS) resources each with 2N1N2 CSI-RS antenna ports, for Coherent Joint Transmission (CJT) Channel State Information (CSI) feedback, wherein N1 and N2 are positive integers;
• send, to the UE, codebook subset restriction (CBSR) information for one or more of the plurality of NZP CSI-RS resources that configures the UE with amplitude restrictions for a subset of spatial vectors or beams on a per NZP CSI-RS resource basis;
• and
• receive, from the UE, CSI based on the configuration information and the CBSR information, wherein the CSI comprises:
• information about a number of layers and a subset of the plurality of NZP CSI-RS resources;
• and
• for each of the subset of the plurality of NZP CSI-RS resources, information for one or more selected spatial domain (SD) basis vectors or beams;
• and
• for each of the number of layers, one or more selected frequency domain (FD) basis vectors, and a set of normalized coefficients each associated to one of the one or more selected SD basis vectors or beams and one of the one or more selected FD basis vectors or beams for each antenna polarization, wherein the one or more selected SD basis vectors or beams are either unrestricted beams or satisfy the amplitude restrictions.