Patent ID: 9402192
Filing Date: 2016-07-26
CPC Classification: H04B,H04W

Claim Text:
1. A method of calibrating antenna reciprocity in a base station of wireless network, wherein a plurality of base stations are configured to conduct intra-site cooperative multi-point processing, the method comprising: determining, based on a predefined rule, a plurality of calibrating user equipments out of a plurality of user equipments, and antennas, to be calibrated by said plurality of calibrating user equipments, of said plurality of base stations, wherein, said plurality of calibrating user equipments are configured to calibrate antennas of said plurality of base stations and said predefined rule is that the number L of antennas of said plurality of calibrating user equipments, the number K of antennas configured for said plurality of base stations and to be calibrated by the antennas of said plurality of calibrating user equipments, and the number M of the antennas of said plurality of base stations satisfy the relation of KL≧M+L−1; and the criteria for channel quality between said plurality of calibrating user equipments and the antennas configured for said plurality of base stations is above a threshold for channel quality; calibrating, according to the determined calibration relationship, the antennas reciprocity of said plurality of base stations based on said plurality of calibrating user equipments, wherein, said calibration relationship is the correspondence between said plurality of calibrating user equipments and the antennas, to be calibrated respectively by said plurality of calibrating user equipments, of said plurality of base stations, wherein said calibrating further comprises: determining the ratio of the reciprocity error of said plurality of base stations relative to that of a first one among the antennas configured for said plurality of base stations, according to the ratio of the reciprocity error of said plurality of base stations to that of said plurality of calibrating user equipments; generating a calibration weight matrix for the uplink channel on said base station side, according to the ratio of the reciprocity error of said plurality of base stations relative to that of said first one among the antennas configured for said plurality of base stations; determining a calibrated transposed matrix for the uplink channel, according to said calibration weight matrix for the uplink channel on said base station side and a transposed matrix for the uplink channel.