非理想定时跟踪下CDMA并行干扰消除检测器的性能

Performance of Parallel Interference Cancellation in DS-CDMA System with Timing Errors

以异步码分多址 (DS CDMA)系统硬判并行干扰消除检测器为模型 ,在定时同步错误情况下 .由于并行干扰消除 (PIC)分析的复杂性 ,以前的工作主要是依靠仿真方法 .文献 [5 ]分析了软判决PIC在定时跟踪错误下的性能 ,给出了封闭形式的误码率表达式 .本文则分析了硬判决PIC残余多址干扰的结构及统计特性 ,导出了定时跟踪错误下封闭形式的误码率表达式 .通过仿真与数值计算 ,分析了定时跟踪错误对硬判决并行干扰消除算法的影响 .

This paper considers a simple model for hard-decision multistage parallel interference cancellation within a code division multiple-access (CDMA) system. Previous work in this area has relied heavily on simulation techniques. The effects of timing errors are analyzed, obtaining a closed form result for bit-error rate after an arbitrary number of stages of cancellation in an additive white Gaussian noise (AWGN) channel. By analyzing statistical characteristics of residual multiple access interference, we obtain an analytical expression for the probability of bit error rate in hard-decision parallel interference cancellation. Calculation results are compared with simulation results.