Reducing time offsets in wireless communications by slowing updating of precoding settings

摘要

Disclosed is a base station (10) configured to reduce temporal variations in interference caused by its transmissions. The base station (10) is comprised of transmission circuits (18) configured to transmit data to a plurality of mobile stations (12) and one or more processing circuits (16). The transmission circuits (18) transmit data via an Orthogonal Frequency Division Multiplex (OFDM) signal comprising a plurality of subcarriers. The subcarriers are transmitted from two or more transmit antennas (14) according to a fixed number of linear precoding weight sets. The processing circuits (16) are configured to form subcarrier sets by assigning each subcarrier to one of the linear precoding weight sets. The processing circuits (16) also assign each mobile station (12) to one of the subcarrier sets and restrict changes to the subcarrier sets to superframe interval boundaries. A superframe interval is defined to be at least several multiples of a channel quality measurement cycle time associated with the mobile stations (12).