一种面向COSPAS/SARSAT系统的改进载波同步算法及其FPGA实现  

An Improved Carrier Synchronization Algorithm and Its FPGA Implementation for COSPAS/SARSAT System

作　　者：赵来定[1] 聂良峰 张更新 ZHAO Laiding;NIE Liangfeng;ZHANG Gengxin(School of Communication and Information Engineering,Nanjing University of Posts and Telecommunications,Nanjing Jiangsu 210003,China)

机构地区：[1]南京邮电大学通信与信息工程学院,江苏南京210003

出　　处：《现代雷达》2024年第12期73-82,共10页Modern Radar

摘　　要：为了实现全球卫星搜救系统中短突发信号的快速载波同步,文中提出了一种基于非数据辅助的改进载波同步算法。该算法首先对输入信号进行非线性处理来消除调制影响,再求取其自相关与共轭相关差值并得出频偏估计值,进行频偏补偿后再通过分段累加和相位跳变检测来完成相偏恢复。该算法在信号处理过程中进行部分相位调整措施,有效提高载波频偏估计精度和降低误码率。实验结果表明:该改进算法在采样频率f s为153.6 kHz时,频偏估计范围为±12 kHz;信噪比为10 dB时,误码率为1.36×10^(-5)。同时,文中给出了该改进载波同步算法的可编程门阵列实现结构,并进行了板级测试验证,测试结果表明其硬件资源消耗不足总系统资源的10%,能满足全球卫星搜救系统中搜救终端短突发信号的载波同步的各项技术指标。To achieve rapid carrier synchronization for short burst signals in COSPAS/SARSAT,an improved carrier synchronization algorithm based on non-data aided techniques is introduced in this paper.The proposed methodology commences with the nonlinear processing of the input signal to mitigate the effects of modulation,followed by the computation of frequency offset estimates derived from the difference between the auto-correlation and conjugate correlation of the signal.Frequency offset compensation is then applied,succeeded by segmental accumulation and phase jump detection to achieve phase offset recovery.The partial phase adjustment measures are incorporated during signal processing,which significantly enhance the precision of carrier frequency offset estimation and diminish the bit error rate.The experimental outcomes demonstrate that the algorithm boasts an estimation range of±12 kHz at a sampling frequency offset f s=153.6 kHz,with a bit error rate of 1.36×10^(-5)at a signal-to-noise ratio of 10 dB.Additionally,the field programmable gate array implementation architecture of the improved carrier synchronization algorithm is delineated in this paper,which has been subjected to board-level testing and validation.The results confirm that the hardware resource consumption is less than 10%of the total system resources,thereby fulfilling the carrier synchronization technical specifications required for short burst signals in COSPAS/SARSAT search and rescue terminals.

关 键 词：全球卫星搜救系统 改进载波同步算法 频偏估计 相偏估计 可编程门阵列实现 

分 类 号：TN791[电子电信—电路与系统]