准同步宽带CDMA卫星移动通信分析

【摘要】理想同步CDMA系统具有很高的容量，然而在卫星移动环境下很难实现，一般采用准同步系统。该文首先仿真分析了准同步误差对宽带CDMA卫星移动通信的影响，发现CDMA系统在准同步的条件下性能有明显改观，也就是说在相同条件下能大大提高系统容量。然后针对卫星移动环境提出了一种准同步实现策略，并对其可行性进行了论证。通过分析可以看出该策略是可行的，并且轨道越高实现越容易。
关 键 词 准同步; 卫星移动通信; 多普勒; 宽带码分多址

The system of synchronous CDMA has large capacity, however it is difficult to implement in mobile satellite condition. So we consider establishing quasi-synchronous system. In this paper, the effect of quasi-synchronous error to broadband CDMA mobile satellite system is analyzed through computer simulation. The performance of CDMA system is improved distinctively in the condition of quasi-synchronous. This paper presented one strategy to realize quasi-synchronous in satellite environment, and discussed its feasibility. After analysis, we find that this strategy is feasible and implemented easier with the increase of orbit elevation.