Method and apparatus for channel state information reporting in a wireless communication system

A method performed by a base station (BS) in a wireless communication system, the method comprising:

• transmitting, to a user equipment (UE), at least one channel state information-reference signal (CSI-RS) configuration and at least one corresponding CSI-RS, wherein the at least one CSI-RS configuration and the at least one corresponding CSI-RS corresponds to at least one transmission reception point (TRP) out of multiple TRPs of the BS;
• receiving, from the UE, a CSI report including transmission parameter feedback corresponding to the at least one TRP of multiple TRP of the BS;
• precoding in at least one TRP data based on the transmission parameter feedback;
• and
• transmitting, to the UE, the pre-coded data in a downlink transmission using the at least one TRP of the multiple TRPs based on the transmission parameter feedback.

A user equipment (UE) in a wireless network system, the UE comprising:

• a memory;
• a processor;
• a communicator;
• and
• a coherent joint transmission controller, coupled to the memory and the processor), wherein the coherent joint transmission controller is configured to:
• receive, from a base station (BS), at least one channel state information-reference signal (CSI-RS) configuration and at least one corresponding CSI-RS, wherein the at least one CSI-RS configuration and one at least one corresponding CSI-RS corresponds to a transmission reception point (TRP) out of multiple TRPs of the BS;
• select a set of basis vectors and corresponding basis coefficients, for representing an entity corresponding to each CSI-RS in a spatial domain (SD), a frequency domain (FD) and a doppler or time domain (DD) for each TRP of the multiple TRPs based on the at least one CSI-RS configuration, wherein the entity is a channel or eigen vector of a channel covariance matrix;
• identify at least one transmission parameter feedback corresponding to at least one of the multiple TRPs based on the selected set of basis vectors and basis coefficients that represents the entity in the SD, the FD and the DD;
• transmit, to the BS, a CSI report of the feedback, wherein the CSI report comprises the at least one transmission parameter corresponding to at least one of the multiple TRPs;
• and
• receive, from the BS, downlink transmission using the at least one TRP based on the transmission parameter feedback.

A base station (BS) in a wireless communication system, the BS comprising:

• a memory;
• a processor;
• a communicator;
• and
• a coherent joint transmission controller, coupled to the memory and the processor, wherein the coherent joint transmission controller is configured to:
• transmit, to a user equipment (UE), at least one channel state information-reference signal (CSI-RS) configuration and at least one corresponding CSI-RS, wherein the at least one CSI-RS configuration and the at least one corresponding CSI-RS corresponds to at least one transmission reception point (TRP) out of multiple TRPs of the BS;
• receive, from the UE, a CSI report including transmission parameter feedback corresponding to the at least one TRP of multiple TRP of the BS;
• precode in at least one TRP data based on the transmission parameter feedback;
• and
• transmit, to the UE, the pre-coded data in a downlink transmission using the at least one TRP of the multiple TRPs based on the transmission parameter feedback.