直扩系统中窄带干扰抑制技术

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...

Suppression technology of narrowband interference in DSSS system

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.