直扩系统中窄带干扰抑制技术  

Suppression technology of narrowband interference in DSSS system

作　　者：郭文飞[1] 郑建生[1] 张提升[1] 吕瀚[1] 

机构地区：[1]武汉大学电子信息学院,湖北武汉430079

出　　处：《解放军理工大学学报（自然科学版）》2011年第5期425-430,共6页Journal of PLA University of Science and Technology(Natural Science Edition)

基　　金：国家部委预研基金资助项目(413220404);中央高校基本科研业务费专项资金资助项目(20102120101000120;20106180201000159)

摘　　要：直扩系统中常常利用能量聚集度对窄带干扰进行定位,然后对干扰所在子带进行处理,从而达到抑制干扰的目的。当某次分解中左右节点中含有相近能量干扰时,将导致能量聚集度均匀而错误停止分解。为了解决这个问题,提出了一种利用多层分解对干扰进行定位的方法。当某节点的能量聚集度小于门限时,强迫子带算法继续分解并求取其子节点能量聚集度,对子节点进行递归操作,预订的多层能量聚集度均小于门限时,才最终断定节点频谱均匀,并将该节点合并。利用变步长自适应小波包变换对直扩系统中窄带干扰抑制进行了仿真。实验结果表明,在干扰处于滤波器组中央时,多层分解能量聚集度判决法仍能有效对窄带干扰进行准确定位。Narrowband interferences in DSSS system used to be located by energy compaction measure,and suppressed in sub-bands.However,if two sub-bands include approximate interference energies,the decomposition will terminate mistakenly.In order to solve this problem,a multi-level decomposition method was proposed to accurately locate narrowband interference（NBI）.A sub-band node was further decomposed even if the energy compact value at this sub-band didn＇t exceed the predefined threshold.Recursive operation was executed to the son-nod untill the predefined multi-level energy values were all lower than the threshold,then the node was regarded as spectrum evenness and combined.Simulations were carried out by using the variable step adaptive wavelet packet transform,with the results that the multi-level decomposition method could accurately locate the NBI even when it was just in the center of the filter-bank.

关 键 词：直接序列扩频 窄带干扰 小波包变换 多层分解 能量聚集度 

分 类 号：TN914.42[电子电信—通信与信息系统]