自适应WPM抗干扰系统中的WPT优选算法研究

为提高自适应小波包调制(WPM)系统抗窄带干扰能力,提出一种基于单音干扰的小波包树(WPT)优选算法.算法以误码率(BER)和有限信号传输能量为条件构造WPT节点处的代价函数,将树优选问题转化为搜索拉格朗日最小代价函数问题,通过剪枝方式搜索窄带干扰下的最优树.理论分析和仿真结果表明,优选算法在窄带干扰环境下能够简单准确地搜索到最优树,在不需要定时发送训练序列的条件下显著提高自适应WPM系统抗窄带干扰能力.

Optimal WPT selection algorithm in adaptive WPM interference rejection system

To improve the narrow band interference (NBI) rejection performance of the adaptive wavelet packet modulation (WPM) system, an optimal wavelet packet tree (WPT) selection algorithm based on tone interference is proposed in this paper. The proposed algorithm makes use of the bit error rate (BER) and the limited transmitted signal power to construct cost function for WPT nodes, which transforms the optimal tree selection problem into the minimization of Lagrange cost function, and the optimal tree is selected by tree pruning method. Analysis and simulation results show that the proposed algorithm can accurately find the optimal tree in NBI environment and performance of the adaptive WPM system is greatly improved without sending the periodic training data.