为消除多用户广播信道下反馈时延和用户速度对系统性能的影响,采用信道的统计信息和过时信息联合估计当前信道信息,在发射端获得了不完全信道状态信息(CSIT).在此基础上,设计了一种鲁棒线性迫零预编码器.仿真结果证明,鲁棒预编码器具有良好的性能,并且验证了系统性能与反馈时延或用户速度的关系.
To eliminate effects of the feedback delay and mobile velocity in broadcast channel, the channel statistics and outdated channel information is used to estimate the current channel state information at transmitter (CSIT) jointly. Based on the obtained imperfect CSIT, a robust linear zero forcing (ZF) precoding is proposed. Simulation shows the performance of robust method is preferable. Furthermore, the relationship between system performance and feedback delay or mobile speed is presented.