一种新的基于时频分析扩频通信去干扰技术

针对DS／SS通信中的非平稳干扰问题，提出了一种新的自适应去干扰方法．经分析得出多重极点滤波器的无限长度冲击响应具有良好的定位性质，类高斯状的时域波形，且其带宽随着极点重数增加而变窄．当把阶数可变的多重极点滤波器用作STFT的分析窗口时，便可以得到一类短时傅立叶变换：利用能量集中方法来选取最佳的分析窗口，计算对应的STFT；得到干扰的域t-f集中分布后，采用二进制掩码的方式将这些干扰去掉；最后对去除干扰后的信号进行译码判决．计算机仿真表明该方法理论正确．可以获得好的误码特性。

A New Approach of Interference Excision in DS/SS Based on Time-frenquency Analysis

A new adaptive jamming excision approach for non-stationary interference signals used in direct sequence spread spectrum(DS/SS)communications is introduced in this paper.Infinite impulse response of a Multi-pole filter features in its satisfied localization both in time and frequency domain,in its Gaussian-like shape and narrowing bandwidth as the number of poles increases.A class of Short Time Fourier Transform can be achieved by using the filter as the analysis window when computing STFT.Then an energy concentration measure is used to select the optimum window and corresponding STFT.After that,the interterence will be concentrated on a small region in t-f plane,which should be excised by using binary masks.Original signal is achieved after detector and translator.Computer simulation demonstrates that the approach is feasible and correct,and it can improve BER performance.