基于三角包络拟合的直扩信号时频二维精估算法  

Time-frequency two-dimensional accurate estimation algorithm of DSSS signal based on trianglar envelope fitting

作　　者：章飚 郭一超 张涛 Zhang Biao;Guo Yichao;Zhang Tao(School of Mechanical Engineering,Tianjin University,Tianjin 300350,China;Tianjin Jinhang Computing Technology Institute,Tianjin 300300,China)

机构地区：[1]天津大学机械工程学院,天津300350 [2]天津津航计算技术研究所,天津300300

出　　处：《战术导弹技术》2023年第2期153-158,共6页Tactical Missile Technology

摘　　要：针对直接序列扩频信号捕获过程中,时频二维搜索估计精度受限于搜索步进的问题,提出一种低复杂度的时频二维精估算法。该算法通过利用直扩信号模糊函数在频率维和时间维剖面的相似性,设计三角包络对时频二维的粗估结果进行拟合,在无需提升系统采样率和处理点数的前提下,可有效提升低信噪比、高动态直扩信号时频二维的估计精度。通过仿真计算,所提出的精估算法可在符号信噪比4 dB时达到超过95%的精化效果,相比传统的直扩信号捕获算法,有效提升了直扩信号的捕获精度。In order to solve the problem in direct sequence spread spectrum(DSSS)signal acquisition that the estimation accuracy of time-frequency two-dimensional search is limited by searching step,a low complexity time-frequency two-dimensional accurate estimation algorithm is proposed.By using the similarity of frequency-time profile of the cross-ambiguity function of DSSS signal,the proposed algorithm designs a triangular envelope to fit the rough time-frequency two-dimensional estimation results,which can effectively improve the time-frequency two-dimensional estimation accuracy of low SNR and high dynamic DSSS signal without increasing the system sampling rate and processing points.In simulation and calculation,compared with the traditional DSSS signal acquisition algorithms,the proposed estimation method can achieve more than 95%precision effect under SNR of 4 dB to effectively improve the acquisition accuracy of DSSS signal.

关 键 词：直扩信号 时频二维估计 包络拟合 估计精度 模糊函数 低信噪比 低复杂度 

分 类 号：TN919.3[电子电信—通信与信息系统]