Method and apparatus for sidelink transmission in wireless communication system

An operating method of a first device which communicates with a second device based on time division duplex (TDD), the operating method comprising:

• receiving, from the second device, a first signal which is based on a single port or two ports;
• estimating a channel matrix between the first device and the second device based on the first signal;
• determining a precoding matrix based on the channel matrix, the precoding matrix comprising a number of right singular vectors that is equal to a rank number of the channel matrix;
• and
• transmitting, to the second device, a precoded physical sidelink shared channel (PSSCH) precoded based on the precoding matrix to the second device,
• wherein the first signal based on the single port comprises at least one of a single port-PSSCH, a physical sidelink feedback channel (PSFCH), a sidelink primary synchronization signal (P-SSS), a sidelink secondary synchronization signal (S-SSS), or a physical sidelink broadcast channel (PSBCH), and
• wherein the first signal based on the two ports comprises a 2 port-PSSCH.

A first device which communicates with a second device based on time division duplex (TDD), the first device comprising:

• a transceiver;
• a memory storing instructions;
• and
• a processor communicatively coupled to the transceiver and the memory, and configured to execute the instructions to:
• receive a first signal from the second device through the transceiver;
• estimate a channel between the first device and the second device based on the first signal;
• generate, by applying singular value decomposition (SVD) to the channel, a first orthogonal matrix comprising one or more left singular vectors, a diagonal matrix comprising one or more singular values, and a second orthogonal matrix comprising one or more right singular vectors;
• select at least one right singular vector from the second orthogonal matrix in descending order according to the one or more singular values, a number of the selected at least one right singular vector is equal to a rank number of the channel;
• and
• transmit, to the second device through the transceiver, a precoded physical sidelink shared channel (PSSCH) precoded based on a precoding matrix and comprising the selected at least one right singular vector.