摘要
在短码直扩信号的伪码序列盲估计中,可采用二倍伪码周期进行分段并使用特征值分解算法、奇异值分解算法或者压缩投影逼近子空间跟踪的算法估计伪码序列。如果非同步时延接近一周期完整伪码序列的始端或者末端时,会出现最大特征值与次大特征值相近,那么此时最大特征向量是最大特征值和次大特征值对应特征向量的线性组合,即最大特征向量存在酉模糊,从而导致从最大特征向量中估计伪码序列的性能较差。针对此问题,利用最大特征向量与次大特征向量存在的重叠特性,对分段后计算出的特征向量进行分析,提出了一种消除盲估计中酉模糊的算法。实验表明,该算法易实现且在低信噪比下性能良好。
In the blind estimation of pseudo-code sequence of short code DS signal,segmentation can be performed at twice the pseudo code period and the Eigenvalue Decomposition(EVD)algorithm,the Singular Value Decomposition(SVD)algorithm or the Projection Approximation Subspace Tracking with delation algorithm(PASTd)can be used to estimate the pseudo-code sequence.If the asynchronous delay is near the beginning or the end of a complete period of pseudo-code sequence,the maximum eigenvalue will be close to the second largest eigenvalue,and the largest eigenvector at this time is a linear combination of the maximum eigenvalue and the second largest eigenvalue corresponding vector,which blurs the estimated largest eigenvector and leads to poor performance in estimating the pseudo-code sequence from the largest eigenvector.To solve this problem,the calculated feature vectors after segmentation is analyzed,and an algorithm is proposed to eliminate the unitary ambiguity by using the overlapping feature between the largest eigenvector and the second largest eigenvector.Experiments show that the algorithm is easy to implement and performs well at low SNR.
作者
张润雨
高勇
ZHANG Runyu;GAO Yong(College of Electronics and Information Engineering,Sichuan University,Chengdu 610065,China)
出处
《无线电工程》
2020年第9期742-747,共6页
Radio Engineering
关键词
伪码序列
盲估计
奇异值分解
酉模糊
重叠特性
PN sequence
blind estimation
singular value decomposition
unitary ambiguity
overlap characteristic
作者简介
张润雨,女,(1995—),就读于四川大学通信与信息系统专业,硕士研究生,主要研究方向:扩频通信;高勇,男,(1969—),博士,教授,主要研究方向:深度学习在通信信号处理中的应用、通信抗截获和通信抗干扰技术、语音信号处理和盲信号处理等,作为项目负责人承担国家省部级科研项目和横向项目20余项,获省部级一等奖1项,已发表论文80余篇。
