异步码分多址系统中盲窄带干扰抑制

对于在频率选择性衰落信道下,异步码分多址系统的窄带干扰的抑制,给出了基于MMSE的权值向量闭合表达式,为了降低算法计算量并自适应更新该闭合表达式,利用子空间方法对该闭合表达式进行逼近,同时利用子空间跟踪方法对该权值向量进行更新。由于该方法只需期望信号特征序列及其时延,因此是一种盲干扰抑制方法。该算法对窄带干扰类型不敏感而且不需要知道干扰模型,因而适用于抑制不同的窄带干扰。对BPSK、多频以及二者的混合窄带干扰模型进行了干扰抑制仿真,结果验证了该算法对不同的窄带干扰模型均可以取得很好的干扰抑制效果。

Blind narrowband interference suppression in asynchronous CDMA systems

For asynchronous direct sequence code division multiple access(DS-CDMA) systems in frequency-selective fading channel,the closed-form expression of the weight vector based on the MMSE principle is presented for narrowband interference suppression is presented.In order to reduce the computational complexity of the algorithm and compute the weight vector adaptively,the subspace method is used to approximate the weight vector expression,and the subspace tracking algorithm is exploited to renew the weight vector.As only the signature sequence and time delay of the desired user is required,the proposed algorithm is blind for interference suppression.The algorithm is nonsensitive to the interference types and does not need the interference models.Simulations with narrowband interference of BPSK,multitone and mixture of both show that the algorithm is suitable to the suppression of various narrowband interferences.