摘要
正交相移键控(QPSK)调制解调方式广泛应用于深空通信、数字卫星通信等高速系统中,高动态QPSK信号具有较大的多普勒载波频偏,针对现有的解调算法对QPSK信号频偏估计范围小、精度较低等问题,提出了一种改进的高动态QPSK信号解调算法。该算法利用基于Zoom-FFT的Quinn频率估计算法对载波频偏进行估计,将频偏估计分为粗估计和精估计两个过程,对估计所得频偏进行补偿后利用Costas环完成载波同步。在MATLAB中对算法进行了仿真,仿真结果表明,该算法能够实现对高动态大频偏QPSK信号的有效捕获,与传统的解调方式相比,该算法对载波频偏的估计范围更大,且具有更高的频偏估计精度和更好的误码性能。
Quadrature phase shift keying(QPSK)modulation and demodulation is widely used in high-speed systems such as deep space communication and digital satellite communication.High dynamic QPSK signals have large Doppler carrier frequency offset.Aiming at the problems of small estimation range and low accuracy of QPSK signals by existing demodulation algorithms,an improved demodulation algorithm for high dynamic QPSK signals is proposed.The Quinn frequency estimation algorithm based on Zoom-FFT is used to estimate carrier frequency offset.The frequency offset estimation is divided into two processes:rough estimation and precise estimation.After compensating the estimated frequency offset,carrier synchronization is completed by Costas loop.The algorithm is simulated in MATLAB.The simulation results show that the algorithm can effectively capture the QPSK signal with high dynamic and large frequency offset.Compared with the traditional demodulation method,the algorithm has a wider range of carrier frequency offset estimation,higher frequency offset estimation accuracy and better bit error performance.
作者
居治毅
陈斌杰
JU Zhi-yi;CHEN Bin-jie(College of Information and Communication Engineering,Harbin Engineering University,Harbin 150001,China;Beijing Institute of Remote Sensing Equipment,Beijing 100854,China)
出处
《信息技术》
2020年第4期32-36,共5页
Information Technology
基金
中央高校基本科研费专项基金(HEUCFP201808)。
