改进K-means算法对AltBOC信号组合码序列的盲估计

Blind Estimation of the Combination Code Sequence for AltBOC Signal with Improved K-means Algorithm

针对恒包络交替二进制偏移载波(Alternate Binary Offset Carrier,AltBOC)调制信号组合码序列难以估计的问题,提出了利用改进K-means算法进行信号组合码盲估计方法。该方法首先通过引入互调分量以及重建副载波的方式构建AltBOC信号模型,然后在接收端将AltBOC信号分段成单倍组合码周期窗长的不重叠观测数据矩阵,并利用相似性原理从观测数据中选择最优的样本作为K-means聚类中的初始均值向量,最后通过K-means算法迭代优化数据样本与其聚类均值向量的平方误差,完成对AltBOC信号组合码序列的盲估计。计算机仿真结果表明,利用该算法在信噪比-15 dB下能够较为精确地估计AltBOC信号组合码序列。

Aiming at the problem that it is difficult to estimate the combination code sequence of Alternate Binary Offset Carrier(AltBOC)signal,an improved K-means algorithm is proposed for blind estimation of AltBOC signal combination code.The method firstly constructs the AltBOC signal model by introducing intermodulation component and rebuilding the subcarrier.Then,the AltBOC signal was segmented into a non-overlapping observation date matrix with period window length of combination code at the receiving end,and the optimal sample was selected from the observation data as the initial mean vector in K-means clustering by using the similarity principle.Finally,the square error of the date sample and its clustering mean vector was iterative optimized by the K-means algorithm to complete the blind estimation of the AltBOC signal combination code sequence.Computer simulation results show that the proposed algorithm can accurately estimate AltBOC signal combination code sequence at SNR-15 dB.