两步法是解决稀疏信号欠定盲分离的一种常用方法,通常首先利用K-means聚类算法估计混叠矩阵,然后利用最短路径法恢复源信号。在使用K-means聚类算法时要求知道源信号的数目,而现实中往往不知道源信号的数目,需要对其进行估计。因此研究了聚类有效性评价指标——BWP指标,结合粒子群算法,提出了一种改进的确定源信号数目的算法,并将这种算法引入到欠定盲分离。实验表明,提出的算法在保证分离精度的同时能缩短分离时间,并可节省一定的内存,在观测信号数据量大时,这种优势更加明显。
Two-step method is a commonly used solution to the underdetermined blind source separation of sparse source sig- nals, K-means clustering algorithm is usually utilized to estimate mixing matrix firstly, and then, the shortest path algorithm is used to recover source signals. The source signal' s number needed in the K-means clustering algorithm is usually unknown in fact, so have to estimate it. This paper studied clustering validity index : BWP index, combined with particle swarm optimiza- tion, proposed a new algorithm to determine the source signal' s number. Then it introduced the proposed algorithm into the un- derdetermined blind source separation. The results of experiment show that the proposed algorithm has good separation preci- sion, meanwhile it can shorten the separation time and save some memory, this advantage is more obvious when the observation data is huge.