Turbo编码GMSK信号的多普勒频移捕获与跟踪  

Doppler Frequency Shift Acquisition and Tracking for Turbo Coded GMSK Signals

作　　者：吴团锋[1,2] 徐友云[1,2] 归琳[1] 马文峰[2] 

机构地区：[1]上海交通大学无线通信技术研究所,上海200240 [2]解放军理工大学通信工程学院,南京210007

出　　处：《电讯技术》2011年第8期61-65,共5页Telecommunication Engineering

基　　金：国家自然科学基金资助项目(60625103;60902018);上海市数字媒体处理与传输重点实验室资助项目~~

摘　　要：提出了Turbo编码GMSK信号的多普勒频移捕获和跟踪方案。该方案首先采用AR模型进行多普勒频移的初始捕获,其次采用基于FFT的联合帧同步和频偏估计算法捕获剩余频差,最后利用判决反馈PLL跟踪多普勒频移的变化。仿真结果表明:该算法在低信噪比时可快速捕获超过符号速率的多普勒频移,并能以很小的误差跟踪多普勒频移的变化,此时解调器误码率性能恶化量较小。A new algorithm of Doppler frequency shift acquisition and tracking for Turbo coded GMSK signals is presented. The signal is captured by AR model and FFT based frame synchronization algorithra. The decision- feedback PLL is employed to track Doppler frequency shift. Simulation results show that the algorithm can cap- ture and track the signal with the frequency shift larger than the symbol rate under low Eb/No, while the amount of demodulation bit error rate（BER） performance degradation is small.

关 键 词：卫星移动通信 GMSK TURBO码 多普勒频移 AR模型 判决反馈PLL环 

分 类 号：TN911.3[电子电信—通信与信息系统]