数字集群通信中GMSK信号的捕获  

Capture algorithm of GMSK signal in digital trunking communication

作　　者：蔡凡[1] 黄佩诚[2] 

机构地区：[1]华南理工大学电子与信息学院,广东广州510640 [2]中国科学院上海天文台,上海200030

出　　处：《江苏大学学报（自然科学版）》2013年第6期675-680,共6页Journal of Jiangsu University：Natural Science Edition

基　　金：国家自然科学基金资助项目(11103066)

摘　　要：针对国内某数字集群系统无法准确估计载波频率偏差,无法使用优于差分解调的准相干解调的问题,设计了一种捕获算法.该算法包含频率估计和符号同步两部分,前者根据集群系统中无线信号的特点及信号的帧格式针对性的设计,使得准相干解调算法得以采用.在频率估计算法中,采用导频信号进行频率估计,比较了多种频率估计算法的性能并给出相关仿真结果.在符号同步算法中,根据准相干解调对位同步性能的要求,利用训练序列完成最佳采样点的检测,保证最佳采样点的检测成功率.结果表明:捕获算法能够保证系统的频率估计性能和位同步性能,提高了系统的解调性能.To solve the problem that the noncohernet demodulation with better performance than differential demodulation couldn＇t correctly estimate carrier frequency error in domestic digital trunking system,a capture algorithm was designed.The algorithm was made up of frequency estimation and symbol synchronization.Depending on the characters of wireless signal and signal frame,the noncohernet demodulation algorithms was adopted in frequency estimation.The results were given through analyzing the pilot signal in the frequency estimation algorithm.Performances of some estimation algorithms were compared,and the relevant simulation results were obtained.According to the requirement of the noncoherent demodulation in symbol synchronization,the optimal sampling site was searched through the training symbols to ensure the detection success rate of optimum sampling site.The results show that the performances of frequency estimation and symbol synchronization are ensured in the proposed capture algorithm,and the demodulation performance of system is improved.

关 键 词：GMSK 捕获算法 频率估计 符号同步 训练序列 

分 类 号：TN965.5[电子电信—信号与信息处理]