在不同的相关系数下,比较了软干扰抵消-最小均方误差(SIC-MMSE)检测器的外信息转移(EXIT)图.分析信道相关系数对迭代接收机收敛特性的影响,确定不同相关系数的迭代接收机工作所需信噪比门限.仿真结果表明,信道的相关系数越大,SIC-MMSE检测器工作所需的信噪比门限就越大;通过比较相关信道和非相关信道的系统误码率性能,在误码率为10^-4时,相关系数ρ=0.5时的信道有2 dB的性能损失.
The channel is correlated under realistic communication environment due to the poor scattering environment. So, it is meaningful to analyze the convergence behavior of iterative receiver for MIMO systems under this case. This paper compared the extrinsic information transfer (EXIT) chart of soft interference cancellation (SIC)-minimum mean square error (MMSE) detector for different channel correlation coefficients. The impact of channel correlation coefficients on the convergence behavior was investigated. Signal to noise ratio (SNR) thresholds for different correlation coefficients were determined with EXIT charts. The simulation results show that the higher SNR thresholds are desired with the increase of channel correlation coefficients. Finally, the hit error rate (BER) performance of uncorrelated channel was compared with that of correlated channel. The iterative receiver has 2 dB performance loss at BER of 10^-4 when the correlated coefficient ρ is equal to 0.5.