Abstract: A method of a first user equipment (UE) may comprise: receiving a downlink (DL) reference signal transmitted by a base station using a beam included in a beam candidate group to be used for sidelink (SL) communication with a second UE; measuring a DL reference signal received power (RSRP) of the DL reference signal; determining a transmit power of a beam included in the beam candidate group based on the measured DL RSRP; and transmitting SL data to the second UE with the determined transmit power.

Abstract: An operation method of a relay node may include: receiving, from a first communication node, first data composed of n bits; receiving, from a second communication node, second data composed of m bits; in response to determining that n is greater than m, generating first T-data of m bits excluding (n-m) bits from the n-bits of the first data and first R-data of (n-m) bits; generating third data by performing a network coding operation on the first T-data and the second data; transmitting the third data to the first communication node; and transmitting the third data and the first R-data to the second communication node.

Abstract: A method of signal transmission based on differentially quantized channel information in a multi-antenna wireless communication system which can transmit signal to multiple mobile stations simultaneously through multiple transmit antennas includes a main codebook reporting step of each mobile station for quantizing channel correlation information (CCI) using a main-codebook and reporting an index of the main codebook, which corresponds to the quantized CCI, to a base station. A sub-codebook reporting step of each mobile station for quantizing the change of the CCI between the quantization interval using a sub-codebook and reporting an index of the sub-codebook, which corresponds to the quantized CCI change, to a base station. A multi-user eigen-beam transmission step of the base station for generating multiple eigen-beams using the index of the main-codebook or sub-codebook reported from mobile stations and transmitting them to multiple users simultaneously.

Abstract: A method of signal transmission based on differentially quantized channel information in a multi-antenna wireless communication system which can transmit signal to multiple mobile stations simultaneously through multiple transmit antennas includes a main codebook reporting step of each mobile station for quantizing channel correlation information (CCI) using a main-codebook and reporting an index of the main codebook, which corresponds to the quantized CCI, to a base station. A sub-codebook reporting step of each mobile station for quantizing the change of the CCI between the quantization interval using a sub-codebook and reporting an index of the sub-codebook, which corresponds to the quantized CCI change, to a base station. A multi-user eigen-beam transmission step of the base station for generating multiple eigen-beams using the index of the main-codebook or sub-codebook reported from mobile stations and transmitting them to multiple users simultaneously.