宽带码分多址系统中正交码的分配策略研究

Study on Dynamic Orthogonal Codes Assignment in Wideband Code Division Multiple Access Communication Systems

对宽带码分多址 (WCDMA)蜂窝移动通信系统中下行链路的正交可变扩频因子 (OVSF)码字分配问题进行了建模分析 .提出采用代价函数来描述码字间干扰和容量性能 ,并基于代价函数制定了OVSF码字分配的方案 ,给出了该分配方案的理论性能计算方法 .对随机分配方法和基于代价函数的分配方法进行了系统仿真 ,仿真结果表明 :代价函数分配方法在不同话务量的情况下 ,都较随机分配方法明显降低了阻塞率 ,有效提高了系统容量 .

The modeling and analysis of orthogonal variable spreading factor (OVSF) codes assignment in wideband code division multiple access (WCDMA) cellular communication systems are presented. An efficient code assignment scheme based on the cost function, which evaluates both the total interference caused by code assignment and the system capacity, is proposed. The theoretical performance of this scheme is derived. System simulation shows that the scheme is more efficient than random code selection scheme in lowering blocking probability and increasing capacity under different traffic conditions.