有限比率反馈下多天线预编码系统的性能分析

在无线通信系统中,当发射端完全已知信道的状态特性时,接收与发送的联合优化设计可获得较好的通信性能,然而由于实际通信系统中有限比率的反馈比特数,发射端往往只能已知部分信道的状态特性。利用格拉斯曼空间中的装填问题,提出通过反馈比特数来选择多波束矢量并与功率控制相结合的线性预编码矩阵优化设计方法。仿真比较了信道特性完全已知和有限比特反馈下部分信道特性已知时基于不同优化准则的预编码系统的性能。仿真同时证实了提出的预编码设计方法的误码率接近信道完全已知时的预编码系统的性能。该设计方法可应用到实际的具有反馈的无线多天线通信系统中。

Performance analysis of precoding multiple antennas systems with finite rate feedback

In wireless communication,when the channel state information(CSI) is perfectly know to the transmitters,better performance can be obtained through joint optimization of transmitters and receivers.However due to the finite rate feedback in real wireless communication systems,only the partial channel sate information is known to the transmitters.In this paper,the linear precoding optimized method with the combination of multiple beam vectors generated by Grassmannian packing method using finite number of feedback bits and power control is proposed.Simulation compare the performance of precoding systems when CSI is perfectly known to the transmitters with partial CSI is know to the transmitters due to finite rate feedback under different criteria.Simulation also verify that the proposed method can approximate the best optimization method when only finite number of bits are feedback to the transmitters.This method can be used in the wireless communication systems with multiple antennas which have feedback channel.