基于PP帧结构的频率估计技术

摘要

针对卫星移动通信系统中短突发信号载波同步的需要,研究了三种基于PP帧结构的频偏估计算法,重点分析并推导了FEPE算法的估计范围和理论估计均方误差值.结果表明,与传统的基于相关函数算法相比,FEPE算法的抗噪声性能更强、估计精度较高;与基于相关函数和的频率估计算法相比,FEPE算法可以在估计范围和估计精度均不受损的情况下,大大降低计算量.理论分析和仿真结果都表明,基于FEPE算法的频率估计器可以兼顾估计性能和计算复杂度的要求,仅利用很少的导频符号就能够获得较高的估计精度,较适合于短突发的卫星移动通信系统.%For the frequency estimation of short burst communication systems, three algorithms based on PP(preamble-postamble) burst format are discussed, then the estimation range of FEPE algorithm and the mean square error of theoretical estimation deduced. Experiment results indicate that compared with the traditional correlation function algorithm, the FEPE algorithm has stronger noise immunity and higher estimation accuracy; while compared with the frequency estimation algorithm based on correlation function, the FEPE algorithm can greatly reduce the computational complexity without any damage on the estimation range and estimation accuracy. Theoretical analysis and simulation results show that the FEPE estimator can satisfy the requirement of estimation accuracy and computation complexity, and achieve high estimation accuracy with a few pilot symbols, and thus, it is more suitable for short burst satellite mobile communication system.