针对实际MIMO系统无线信道存在的空域相关性,提出了一种基于相关信道统计的改进算法。基于此算法,并采用随机码本量化信道信息形成一种新波束形成方案,它只需要有限速率反馈部分信道信息,可以同时获得系统多用户分集增益和阵列增益,解决了常规波束形成需要大量信道反馈信息和相干波束形成系统性能对信道瞬时变化信息敏感的问题。仿真结果表明,提出方案在相关信道下相当有效,其性能超过常规波束形成,即使在有限反馈限制条件下,其性能亦接近相干机会波束的性能,仅有0.2bit/s·Hz-1的性能损失。
Due to tile spatial correlation of the real MIMO(Multiple- Input Multiple- Output) channels, an improved finite-rate feedback beamforming algorithm based on the correlation channel statistic is proposed by the use of random vector codebook to quantize the channel state information. The novel beamforming scheme only needs limited feedback channel state information and can exploit multi-user diversity gain and anay gain simultaneously. Superior to the conventional beamforming and coherent opportunistic beamforming, the novel beamforming is neither in need of lots of feedback information nor sensitive to instantaneous change of channel. The simulation results show that the performance of the proposed scheme is better than that of the conventional beamforming and approximates to that of coherent beamforming with only 0.2 bit/s·Hz-1 performance loss.