High Sensitivity Acquisition Algorithm for DSSS Signal with Data Modulation

作     者：SHEN Yuyao WANG Yongqing CHEN Jingyao WU Siliang 

作者机构：School of Information and ElectronicsBeijing Institute of Technology 

出 版 物：《China Communications》 (中国通信（英文版）)

年 卷 期：2015年第12卷第4期

页      面：76-85页

核心收录：

学科分类：11[军事学] 0810[工学-信息与通信工程] 1105[军事学-军队指挥学] 08[工学] 081002[工学-信号与信息处理] 110503[军事学-军事通信学] 

基　　金：the support of the National High Technology Research and Development Program of China (863) (Grant No. 2012AA1406) 

主　　题：DSSS signal acquisition dataphase prediction data polarity inversion segment search high sensitivity 

摘      要：In direct sequence spread spectrum communication both for satelliteto-ground and inter-satellite links, the system constrains due to radio frequency spectral occupation, channel data throughput and link performances in terms of data channel coding which might result in a signal structure where the symbol duration is shorter than the pseudo code period. This can generate some difficulties in the DSSS signal acquisition due to the polarity inversion caused by the data modulation. To eliminate the influence due to polarity inversion, this paper proposes a novel acquisition algorithm based on the simultaneous search of the code phase, data phase and Doppler frequency. In the proposed algorithm the data phase is predicted and the correlation period for the coherent integration can be set equal to the symbol duration. Then non-coherent accumulation over different symbol is implemented in order to enhance the acquisition algorithm sensitivity; the interval of non-coherent accumulation is the least common multiple between the symbol duration and the pseudo code period. The algorithm proposed can largely minimize the SNR loss caused by data polarity inversion and enhance acquisition performance without a noticeable increase in hardware complexity. Theoretical analysis, simulation and measured results verify the validity of the algorithm.