二维扩频系统同步技术研究  

Synchronization Technology Research of Two-Dimensional Spread Spectrum System

作　　者：王晓涓[1] 牛小梅[1] 

机构地区：[1]黄淮学院,河南驻马店463000

出　　处：《现代电子技术》2008年第6期133-136,140,共5页Modern Electronics Technique

摘　　要：二维扩频通信系统是近年来提出的新的扩频通信方式,由于二维扩频系统从时域和频域上分别对数据信号进行频谱扩展,因此他同时具有时域扩频和频率扩频通信系统的特点。对于一个实际系统而言,同步是信号正确解调和恢复的前提。针对二维扩频特殊的时频域扩频矩阵结构,提出广义二维扩频矩阵的时间同步算法:该算法将二维扩频矩阵等效为一个一维时间序列,采用序贯捕获的方法捕获此时间序列的第一径,从而完成二维扩频矩阵的时间捕获。该算法不需要在数据序列中插入循环前缀,因而减少了系统开销,提高了带宽利用率。同时,对其在瑞利衰落环境中的同步性能进行详细的理论分析和推导。分析结果表明:该同步方法简单,具有良好的同步性能。Recently, two - dimensional Spread Spectrum （2D- SS） system has drawn a lot of attention because of its full utilization of spreading characteristics in the frequency domain and time domain. Compared with Multicarrier Code Division Multiplex Access （MC- CDMA）, 2D- SS system can effectively mitigate Multiple Access Interference （MAI） due to spreading in the time domain. As for a communication system in practical, synchronization should be firstly done at the receiver. This thesis,a method of time synchronization of 2D- SS system in multipath fading channels has been proposed. The detection probability and false - alarm probability are analyzed and also the numerical results on condition of different normalized thresholds are presented. Results show that the serial acquisition needs no cyclic prefix and the spectral efficiency increases. Meanwhile, the synchronization algorithm in the DS- SS system can be used in 2D- SS system,and good synchronization performance can be obtained, with its algorithm simplified.

关 键 词：二维扩频 同步技术 一维时间序列 时间捕获 

分 类 号：TN914.42[电子电信—通信与信息系统]