一种适用于散射通信的联合帧同步和频偏估计算法研究  

Study on Joint Frame Synchronization and Frequency Bias Estimation Algorithm for Tropospheric Scattering Channels

作　　者：吕子豪 张涛[1] 任文成[1] LYU Zihao;ZHANG Tao;REN Wencheng(The 54th Research Institute of CETC,Shijiazhuang 050081,China)

机构地区：[1]中国电子科技集团公司第54研究所,石家庄050081

出　　处：《计算机测量与控制》2024年第1期185-191,200,共8页Computer Measurement &Control

摘　　要：针对对流层散射通信中存在的多径衰落以及收发两端频偏,对一种适用于对流层散射通信的联合帧同步和频偏估计算法进行了研究;设计了一种适用于对流层散射通信的新型同步帧结构,其在帧同步信息前增加了周期循环PN序列用于辅助判决,能够提高衰落信道下的信号起点捕获概率;采用基于FFT的部分相关频域捕获算法,搜索最大相关值和频偏索引,同时完成了帧同步和频偏估计;在多径衰落和频偏影响下实现了联合帧同步和频偏估计算法;仿真结果表明:在衰落速率5 Hz,频偏1000 Hz散射信道下,正确捕获到帧同步信息概率在-4 dB信噪比下仍可达到90%以上,且频偏估计偏差在0.4 Hz以内。Aimed at the multipath fading and frequency offset of transmitter and receiver ends in tropospheric scattering communication,a joint frame synchronization and frequency offset estimation algorithm for tropospheric scattering channels is studied.A new synchronous frame structure for tropospheric scattering communication is designed,it adds a cyclic PN sequence before the frame synchronization information to assist the decision,it can improve the probability of signal starting point acquisition in fading channels.A partial correlation frequency domain is used to capture algorithm based on FFT transformation,search for the maximum correlation value and frequency offset index,and then complete the frame synchronization and frequency offset estimation.The joint frame synchronization and frequency offset estimation algorithms are implemented under the influences of multipath fading and frequency offset;Simulation results show that in a scattering channel with a fading rate of 5 Hz and frequency offset of 1000 Hz,the probability of correctly capturing the frame synchronization information still reaches over 90%at a signal-to-noise ratio of-4 dB,and the frequency offset estimation deviation is within 0.4 Hz.

关 键 词：散射通信 抗衰落 帧同步 频偏估计 FFT变换 

分 类 号：TN926[电子电信—通信与信息系统]