摘要: |
针对长码直接序列扩频(DSSS)信号的伪随机码(PN)盲估计问题,提出了一种新的周期
长码直接序列扩频信号(PLC DSSS)模型。该模型等同于虚拟多用户短码扩频DS-CDMA系统,
采用DS-CDMA的谱范数来估计同步偏移,该算法不需要更多假定限制,利用相关函数二阶矩
、特征值分解和模糊酉矩阵方法就可以完成伪码序列的估计。实验结果表明,在较低信噪比
下就可以完成对PN码序列的精确估计,表现出良好的性能。 |
关键词: 直接序列扩频 周期长码 PN码 虚拟多用户 失
步点盲估计 |
DOI: |
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基金项目:国家自然科学基金资助项目(61071196);国家自然科学基金-
中物院NSAF联合基金项目(10776040);教育部新世纪优秀人才支持计划项目(NCET-10-09
27)
;信号与信息处理重庆市市级重点实验室建设项目(CSTC,2009CA2003);重庆市自然科学
基金资助项目(CSTC,2009BB2287, 2010BB2398, 2010BB2411) |
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PN Sequence Estimation of Long code DSSS Signals Based on Virtual Multiuser Model |
BAI Juan,ZHANG Tian-qi,ZHAO De-fang,BAI Rui |
(Chongqing Key Laboratory of Signal and Information Processing,Chongqing University of Posts and Telecommunications,Chongqing 400065,China) |
Abstract: |
For the blind estimation of long-code direct sequence spread spectrum(
DSSS)signals, a new periodic long code(PLC) DSSS signals model as equivalent to
a virtual multiuser short-code DSSS system is presented. The spectral norm in th
e DS-CDMA system is exploited to estimate the synchronous offset, then second-or
der correlation function, eigenvalue decomposition and ambiguity matrix methods
are employed to estimate long-code spreading codes, without further restricting
assumptions. Experimental results show that the algorithm can complete preci
sely the estimation of PN code in low SNR. The proposed algorithm has good p
erformance. |
Key words: DSSS periodic long code PN code virtual multiuser blind estimation of desynch
ronizing point |