研究了接收相关瑞利衰落对垂直分层空时码最大似然接收机比特差错性能的影响.研究发现,最大似然接收机的平方欧氏距离为加权卡方分布随机变量之和.以此为基础推导给出成对差错概率精确及高信噪比近似计算公式,并利用高信噪比近似公式定量分析接收相关性对最大似然接收机分集增益及信噪比损失的影响.研究表明,接收相关性造成分集增益损失等于接收天线数与接收相关矩阵秩之差;接收相关矩阵满秩情况下,信噪比损失由接收相关矩阵的行列式及接收天线数联合确定.计算机数值仿真结果验证了理论分析的正确性.
The performance of vertical Bell labs layered space-time (V-BLAST) over receive correlated Rayleigh fading channel is investigated. The squared Euclidean distance is observed to be the sum of weighted-chi-squared-distributed random variable. Based on the observation, a new exact expression of the pairwise error probability (PEP) is presented. The asymptotic result of the PEP for high signal-tonoise ration (SNR) is used to quantify the loss of the diversity order and the penalty of SNR. It is shown that the loss of diversity order equals to the difference of the number of receiver antennas and the rank of receive correlation matrix, and, under that assumption that the receive correlation matrix has full rank, the penalty of SNR is jointly determined by the determinant of the receive correlation matrix and the number of receive antennas. Simulation results are given to corroborate the theoretical analysis.