基于数字联合载波跟踪环的卫星遥测数据解码  

Satellite Telemetry Data Decoding Based on Digital Joint Carrier Tracking Loop

作　　者：朱贺 张胜利[1] ZHU He;ZHANG Sheng-li(School of Information Engineering,Shenzhen University,Shenzhen 518060,China)

机构地区：[1]深圳大学信息工程学院,深圳518060

出　　处：《科学技术与工程》2019年第5期162-166,共5页Science Technology and Engineering

摘　　要：为了解决在没有多普勒补偿设备的情况下,多普勒频移对微小卫星遥测数据解码的结果及质量的影响,对现有的卫星遥测数据解码器改进,提出了一种基于二阶锁频环与二阶锁相环联合的载波跟踪解码方案。首先将粗捕捉的遥测基带数据信号经锁频环跟踪较大的多普勒频,当检测到频差小于设定阈值时,联合载波环路切换到锁相环状态下进行精确跟踪,最终使载波频率准确地牵引到多普勒频偏,完成载波同步。最后通过GNU Radio平台进行解码实验验证,结果表明:该方案载波跟踪精度高和解码数据包正确率优于传统卫星遥测数据解码方法。In order to solve the effect of doppler frequency shift on the decoding result and quality of microsatellite telemetry data without doppler compensation equipment, an improved second-order lock is proposed for the existing satellite telemetry data decoder and a carrier tracking scheme based on the combination of second-order frequency-locked loop and second-order phase-locked loop is proposed. Firstly, the coarsely captured telemetry baseband data signal is tracked by the frequency-locked loop to a larger doppler frequency. When the detected frequency difference is less than a certain threshold, the joint carrier loop is switched to the phase-locked loop state for accurate tracking, and finally the carrier is finally obtained. The frequency is accurately pulled to the doppler shift and the carrier synchronization is completed. Finally, the decoding experiment is verified by GNU Radio platform. The results show that the carrier tracking accuracy of this scheme is high and the correct rate of decoded data packets is better than the traditional satellite telemetry data decoding method.

关 键 词：微小卫星通信 载波跟踪 锁相环 锁频环 

分 类 号：TN927[电子电信—通信与信息系统]