DS-CDMA系统中最大比合并的性能分析

Performance Analysis of Maximal Ratio Combining Diversity in DS-CDMA Systems

该文推导了存在信道估计误差的DS-CDMA系统在多径Rayleigh衰落信道中的误码率.数值计算结果表明当实际系统中的信道估计存在误差并且信道多径功率不等时,在假设相等噪声功率和理想信道估计下得到的传统最大比合并方法因无法输出最大的信噪比而性能明显下降.

A new expression for the Bit Error Rate(BER) of a Direct-Sequence Code-Division Multiple-Access (DS-CDMA) system with non-ideal channel estimation in a frequency-selective Rayleigh fading channel is derived and evaluated. The analysis assumes an arbitrary number of independent, but non-identical resolvable paths combined by the conventional Maximal Ratio Combining(MRC) algorithm which is known to produce maximal signal-to-noise ratio for diversity channels with equal noise powers and perfect channel estimates. The results obtained show that in such systems, the effects of non-identical fading and the channel estimation error on system performance cannot be ignored.