TAS/STBC系统在相关Rayleigh信道下的性能分析

Abstract

针对相关Rayleigh信道，研究了使用发射天线选择(TAS)和正交空时分组码(OSTBC)的多输入多输出(MIMO)系统的平均符号误码率(ASEP)性能。首先采用了非常适合室内信道的Laplacian模型，得到了两个天线之间的相关系数，它是天线间隔，功率方位角谱(PAS)的标准差和平均到达角(AOA)三者的函数。然后引入了相关矩阵，建立了TAS/STBC系统的相关信道模型，基于等效的标量加性高斯白噪声(AWGN)信道的方法，得到了系统在接收端信噪比的表达式。最后对不同条件下的系统的平均符号误码率(ASEP)性能做了仿真，仿真结果表明：TAS/STBC系统的ASEP性能受到空间相关性的影响，尤其是天线间隔，功率方位角谱(PAS)的标准差和平均到达角(AOA)三者的影响。 The average symbol error probability (ASEP) of multiple-input multiple-output (MIMO) systems employing transmit antenna selection (TAS) and orthogonal space-time block code (OSTBC) over correlated Rayleigh fading channels is considered. We first derive the correlation coefficients between two antenna elements as a function of the antenna spacing, the standard deviation of the power azimuth spectrum (PAS) and the mean angle of arrival (AOA) for the truncated Laplacian model, which is appropriate for indoor channels. Then we introduce the correlation matrix, and establish a correlated channel model. Based on the equivalent scalar additive white Gaussian noise (AWGN) channel approach, the exact form expressions of the signal-to-noise ratio (SNR) at the receiving end are derived. The system performance under different conditions was evaluated through numerical simulations. Numerical results show that: the ASEP performance is affected by the spatial correlation, which varies according to the antenna spacing, PAS standard deviation and mean AOA.