分析了反馈时延对于迫零(zero-forcing, ZF)波束形成系统和容量性能的影响，提出采用最小均方误差信道预测技术补偿反馈时延. 基于ZF系统信干噪比的概率密度函数，推导了信道信息存在误差时该系统和容量期望的解析表达式. 数值仿真表明，预测器有效利用了信道的时间相关性，补偿了反馈时延带来的容量损失，仿真结果与理论分析结果吻合.
In this paper, capacity degradation of zero-forcing beam forming (ZFBF) system due to outdated CSI is investigated. A linear minimum mean square error (MMSE) channel predictor is employed to cope with the feedback delay and improve the capacity performance. Based on the power density function of the system’s signal to interference plus noise ratio (SINR), the analytic sum capacity expression relevant to the prediction error is derived. Numerical simulations show effectiveness of the predictor that exploits the channel’s temporal correlation against feedback delay. The simulation results are consistent with the analytic research.
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