多载波系统多用户信号检测的一种新方法

A New Approach for Multiuser Detection for Multicarrier System

为了解决多载波直扩码分多址(MC-DS-CDMA)系统中的多址干扰问题,将克隆选择算法应用于该系统的多用户信号检测,充分利用免疫理论中的克隆选择算法组合优化的能力,来同时确定每一个用户传输的符号位.研究结果表明,该检测方法不仅克服了该系统的多址干扰,而且通过调整算法的参数,可以在检测时间和系统平均误码性能间进行均衡.与最佳多用户检测器相比明显降低了计算复杂度,在相同带宽相同检测算法的条件下,获得了比DS-CDMA系统更好的特性.

In order to resolve multiple access interference （MAI） in Multicarrier Direct Sequence CDMA （MC -DS- CDMA） system we applied Clonal selection algorithm （CLONALG） as a suboptimal multiuser detection technique in the system over fading channels, using combinatorial optimization ability of CLONALG to determine special combination of each user symbol bit transmitted. It is shown that the proposed CLONALG scheme detector not only has the performance of combating multiple access interference （MAI） but also offer a trade - off between an average BER performance and detection time by adjusting its parameters. Comparing with optimum multiuser detection, the CLONALG scheme can obviously reduce computational complexity. Furthermore, the system has better performance than DS- CDMA system under the same bandwidth and the same channel conditions.