CDMA中匹配滤波波束形成器的一种新的算法

Novel algorithm of matched filter beamformer in CDMA

基于适于CDMA的匹配滤波波束形成准则 ,提出使用幂法计算权矢量的波束形成的新方法 .根据相关阵为对称正定阵、特征值全为正数和最大特征值远大于第二大特征值的特点 ,通过幂迭代的方法求得最大特征值和最大特征矢量 ,进而进行波束形成 .该算法比已有的共轭梯度法方法收敛速度快 ,每次迭代的乘法数由O( 5N2 + 5N)减少到O(N2 +N) .本文从理论上分析和仿真验证了该算法收敛特性与干扰信号功率、信噪比和扩频比的关系 .

Based on the matched filter beamforming criterion in CDMA, a novel method called power method is proposed to compute the weight vector to beamform. For the correlation of matrix is symmetric positive,all eigenvalue positive valued, and the largest eigenvalue being much larger than the second largest eigenvalue, the largest eigenvalue and the largest eigenvector can be obtained by power method, and beamforming can be done.This method has the advantage of faster convergence than the conjugate gradient method and the computation load of multiplication for each iteration of power reduce from 0(5N2 +5N) to O(N2+N). The relation of the convergence of this algorithm with the spreading rate, interferential power, and the SNR (signal noise rate) is analyzed theoretically and examined through simulation.