一种改进的MRT预编码方案

Modified MRT Precoding Scheme

最大比传输(Maximum Ratio Transmission,MRT)预编码是以最大化期望信号的输出信干噪比为设计原则得到的预编码方案。它通过对信道矩阵求共轭转置来获取发送预编码矩阵,计算复杂度低,频谱效率低。通过增加MRT预编码的期望用户的信道增益,改善MRT预编码的性能,引出了一种改进的MRT预编码方案(Improved Maximum Ratio Transmission,Improved-MRT),并根据MRT预编码在瑞利衰落信道下的闭式表达式得到Improved-MRT的频谱效率、中断概率、中断容量的近似闭式表达式。

MRT(Maximum Ratio Transmission)precoding is a precoding scheme based on maximizing the output signal-to-interference and noise ratio of the desired signal.It obtains the transmission precoding matrix by conjugate transpose of the channel matrix,with low computational complexity and low spectral efficiency.By increasing the channel gain of the desired user of MRT precoding and improving the performance of MRT precoding,a modified MRT(Maximum Ratio Transmission)precoding scheme is introduced.At the same time,according to the closed-form expression of MRT precoding under the Rayleigh fading channel,approximate closed-form expressions of the spectrum efficiency,outage probability and outage capacity of modified MRT are obtained.