FIELD: radio engineering, communication.
SUBSTANCE: invention relates to wireless communication systems and is intended to improve the codebook format, which provides efficient identification and transmission of channel state information by a device to a base station. The invention describes a method of selecting a group of beams and a subset of beams in a communication system, which includes: measuring channel state information (CSI) on a downlink from a base station (920); identifying a selected beam group from of a set of beam groups according to a wideband property of the CSI (930), and identifying a selected subset of beams in the selected beam group according to at least one subband (940). The characteristic of the set of beam groups depends on a transmission rank and the number of beams in the selected subset of beams is equal to the transmission rank. The method further includes: generating encoded feedback information identifying the selected beam group and the selected subset of beams for each subband in a double codebook format (950), and transmitting the encoded feedback information to the base station.
EFFECT: improved codebook format.
28 cl, 11 dwg
