基于比特域叠加训练序列的载波同步方法  

Carrier Synchronization Method Based on Bit-level Superimposed Training Sequence

作　　者：李姗姗 陈为刚 LI Shanshan;CHEN Weigang(School of Microelectronics,Tianjin University,Tianjin 300072,China)

机构地区：[1]天津大学微电子学院,天津300072

出　　处：《信号处理》2022年第5期946-953,共8页Journal of Signal Processing

基　　金：青岛试点海洋国家实验室主任基金(QNLM201712)资助项目。

摘　　要：针对突发通信面临的频偏较大和频谱资源有限的问题,本文提出一种基于比特域叠加训练序列的载波同步方法。该方法在发送端将稀疏化后的编码码字与训练序列在比特域通过模二加的方式相叠加,使得训练序列隐藏于发送数据中,在传输过程中共用频谱资源,增强突发通信的抗截获能力;在接收端提出一种抗干扰能力较强的载波同步方案,该方案利用隐藏训练序列进行频偏估计,并使用粗同步与精同步相结合以提高估计精度。仿真结果表明,所提出方案在低信噪比下实现精确度较高的频偏估计,具有±0.45的频偏捕获范围,相比于基于时分复用系统的载波同步方案在低信噪比(-4 dB)下有更加精确的频偏估计性能,并且在AWGN信道下和瑞利衰落信道下通信系统性能分别有0.5 dB和0.7 dB的增益。For the problems of large carrier frequency offset and limited bandwidth resources in burst communication,a scheme based on bit-level superimposed training sequence is proposed. At the transmitter,the sparse coding codewords is superimposed on the training sequence by modulo-2 bit-by-bit,so that the training sequence is implied in the transmitted data and they share spectrum resources during transmission. And the superposition scheme can enhance the antiinterception ability of burst communication. At the receiver,a carrier synchronization method with strong anti-interference ability is proposed. The method uses the hidden training sequence to complete the carrier frequency recovery,and the coarse frequency estimation and the fine frequency estimation are combined to improve the estimation accuracy. The simulation results show that the scheme has a frequency offset capture range of ±0.45. Compared with the synchronization scheme based on time-division multiplexing(TDM)system,the synchronization proposed scheme can estimate frequency offset more accurately at low signal-to-noise ratio(SNR)(-4 dB),and has a gain of 0. 5 dB and 0. 7 dB in AWGN channel and Rayleigh fading channel respectively.

关 键 词：突发通信 低信噪比 载波同步 比特域叠加训练序列 

分 类 号：TN911.23[电子电信—通信与信息系统]