多输入多输出系统下低复杂度的自适应预编码方法

Adaptive Precoding Method with Low-Complexity for Multiple-Input Multiple-Output Systems

针对多输入多输出衰落信道中存在的码间干扰和多径干扰问题,提出了一种具有低复杂度的自适应预编码方案.该方案在发送端和接收端分别放置了预编码器和基于迫零算法的接收机,这样接收机在进行均衡译码的同时,将信道信息反馈给发送端,发送端便可以随之选择发送子载波的数目以及预编码矩阵,完成自适应预编码.该方案可有效降低系统的误码率.仿真结果表明,当误码率为10-3时,在传输信道信息未知的情况下,该方案的信噪比比信道信息已知的基于最小均方误差预编码方案高1.3 dB,且复杂度大大降低.

Focusing on the problem that the intersymbol interference and multipath interference exist in multiple-input multiple-output fading channels, a scheme of adaptive precoding with lowcomplexity is proposed, in which the precoder and the receiver based on zero forced algorithm are placed at transmitter and receiver respectively. So the receiver transmits the channel information to the transmitter while the equalized decoding is carried out, then the transmitter can choose the number of the substreams and the precoding matrices to complete the adaptive precoding. The scheme can decrease the bit error rate of the system effectively. Simulation results show that there is a 1.3 dE phase difference between the proposed scheme and the system based on minimum mean-square error precoding with known channel information under the condition that the channel information is unknown when the bit error rate is 10^-3, and the complexity is decreased by order of magnitude.