CDMA系统中一种反向链路自适应波束成形算法

An inverse link adaptive beamforming algorithm for CDMA system

在已有波束成形算法基础上,针对码分多址(CDMA)系统反向链路,给出相应智能天线信号模型及性能分析;并基于最大功率输出准则,采用幂法迭代计算,提出一种适合于高速环境的自适应波束成形算法。与原有一些算法相比,该算法仅计算解扩后信号的最大特征矢量,有效地降低了计算量,且性能稳定;可很好地应用于高速车载多径环境。计算机仿真结果表明在相同衰落情况下所提算法性能可接近于性能较好的码滤波法,但复杂度远低于后者,从而实现了以低的计算复杂度获得较好的系统性能。

On the basis of existing beamforming algorithm, we give corresponding smart antenna signals model and performance analysis for inverse link in the CDMA system. According to maximum power output criteria, we also propose an adaptive beamforming algorithm for high speed environment by using power iterative method. Compared with some existing algorithms, the proposed algorithm can decrease the computational complexity by only calculating maximum eigenvector of the depreaded signal matrix. It has steady performance, and can be applied to high speed vehicle scenario well. Simulation results show that the proposed algorithm can achieve almost the same performance with the code-filtering method which has superior performance under same fading situation, but our algorithm has lower complexity than the latter. Thus the algorithm implements good performance with low complexity.