Method and apparatus for codebook-based physical uplink shared channel (pusch) transmission

A User Equipment (UE) for performing codebook-based Physical Uplink Shared Channel (PUSCH) transmission, the UE comprising:

• at least one processor;
• and
• at least one non-transitory computer-readable medium coupled to the at least one processor and storing one or more computer-executable instructions that, when executed by the at least one processor, cause the UE to:
• receive, from a Base Station (BS), a Radio Resource Control (RRC) message comprising a PUSCH configuration, the PUSCH configuration indicating a codebook-based PUSCH transmission;
• receive, from the BS, a Downlink Control Information (DCI) format comprising a first field and a second field, the first field indicating an 8-port Sounding Reference Signal (SRS) resource, and the second field indicating an index that is associated with a Transmission Precoding Matrix Indicator (TPMI) and a number of transmission layers;
• determine a number of codewords to be one in a case that the number of transmission layers is less than or equal to four;
• determine the number of codewords to be two in a case that the number of transmission layers is greater than four;
• determine a codeword-to-layer mapping for spatial multiplexing based on the number of transmission layers and the number of codewords;
• determine a precoding matrix based on the index and the codeword-to-layer mapping for the spatial multiplexing;
• and
• perform the codebook-based PUSCH transmission using the precoding matrix.

A Base Station (BS) for configuring codebook-based Physical Uplink Shared Channel (PUSCH) transmission, the BS comprising:

• at least one processor;
• and
• at least one non-transitory computer-readable medium coupled to the at least one processor and storing one or more computer-executable instructions that, when executed by the at least one processor, cause the BS to:
• transmit, to a User Equipment (UE), a Radio Resource Control (RRC) message comprising a PUSCH configuration, the PUSCH configuration indicating a codebook-based PUSCH transmission;
• and
• transmit, to the UE, a Downlink Control Information (DCI) format comprising a first field and a second field, the first field indicating an 8-port Sounding Reference Signal (SRS) resource, and the second field indicating an index that is associated with a Transmission Precoding Matrix Indicator (TPMI) and a number of transmission layers, wherein the DCI format enables the UE to:
• determine a number of codewords to be one in a case that the number of transmission layers is less than or equal to four;
• determine the number of codewords to be two in a case that the number of transmission layers is greater than four;
• determine a codeword-to-layer mapping for spatial multiplexing based on the number of transmission layers and the number of codewords;
• determine a precoding matrix based on the index and the codeword-to-layer mapping for the spatial multiplexing;
• and
• perform the codebook-based PUSCH transmission using the precoding matrix.