长码DS/CDMA系统中的预优软判决多用户干扰消除

THE PRECONDITIONED SOFT DECISION MULTIUSER INTERFERENCE CANCELLATION IN LONG-CODE USED DS/CDMA SYSTEMS

在长码DS/CDMA通信系统中,多级线性软判决并行多用户干扰消除(LSD-PIC)检测器的收敛性能受限于用户数,该文提出用矩阵计算的预优方法改进LSD-PIC检测器的收敛性能,克服由于系统高负载造成的LSD-PIC检测器的性能崩溃,并提出了低代价多项式预优子的概念,对零阶和一阶多项式预优子分别给出了最优系数。

In long-code used DS/CDMA communication systems, the convergence of performance is limited by the number of users in multi-stage Linear Soft Decision Parallel Interference Cancellation (LSD-PIC) multiuser detectors. In this paper, the precondition method in matrix computation is proposed to be applied to improve the convergence of iteration and overcome the convergence breakdown in the case of high load for the LSD-PIC multiuser detectors. Furthermore, the polynomial preconditioner which could be obtained by low computational complexity is proposed, and the optimal coefficients for zero-order and first order polynomial preconditioner are deduced.