一种1090ES相位编码信号的同步算法

载波同步是对1090MHz扩展电文(1090MHz Extended Squitter,1090ES)的相位编码信号进行相干解调的前提和基础,研究针对这种调制方式的基于数据辅助的载波频偏估计算法。构建了1090ES相位编码信号的频偏估计模型,提出了一种基于遗传算法的频偏估计算法,详述了该算法的特点及其实现步骤,并通过MATLAB仿真,分析比较了该算法与Kay算法、Fitz算法及M&M算法的频偏估计性能。该算法的频偏估计范围可以达到采样频率的50%,在信噪比高于3 dB时,频偏估计的均方误差接近于修正的克拉美罗界,并且可以同时兼顾频偏估计精度和频偏估计范围。

A Synchronization Algorithm of 1090ES Phase-Coded Signal

Carrier synchronization is the premise and basis for coherent demodulation of phase-coded signal. This paper discusses data-aided frequency offset estimation algorithm in 1090MHz Extended Squitter, 1090ES ( Extension System ).A novel frequency estimation model suitable for 1090ES phase-coded signal is constructed, and a frequency offset estimation algorithm based on genetic algorithm also proposed. The characteristics and implementation steps are described in detail, and the frequency offset performance is analyzed and compared with Kay algorithm, Fitz algorithm and M&M algorithm via MATLAB simulation.Experiment results show that the frequency offset estimation range of the proposed algorithm can reach 50% of the sample frequency, and the mean square error of frequency offset estimation is close to MCRB when SNR is lower 3dB. In addition, the proposed algorithm could give consideration to both estimation precision and estimation range.