基于谱特征分析的BPSK信号关键参数估计方法  

Key Parameters Estimation Method of BPSK Signal Based on Spectral Analysis

作　　者：朱航 邹晓鋆 谭铭 许旭光 韩立珣 宋伟[1] ZHU Hang;ZOU Xiaojun;TAN Ming;XU Xuguang;HAN Lixun;SONG Wei(College of Information and Communication,National University of Defense Technology,Wuhan,Hubei 430000,China)

机构地区：[1]国防科技大学信息通信学院,湖北武汉430000

出　　处：《信号处理》2025年第3期472-483,共12页Journal of Signal Processing

基　　金：国家自然科学基金(62201579,62201580)。

摘　　要：针对非合作通信中所截获的根升余弦脉冲成形二进制相移键控(Binary Phase Shift Keying,BPSK)信号,创新性地将其建模为周期调制信号,并对周期调制信号分段观测矩阵的奇异值分解结果进行了必要分析,明确了单分量及多分量情况下奇异值分解的结构性特点,在此基础上结合信号自身特点提出了对符号速率、载频、滚降系数、延迟量等关键参数进行估计的新方法。首先通过对接收信号的功率谱及其直方图进行分析,利用噪声功率谱恒定的特点,实现对信号符号速率及载频的粗估计,在此基础上通过对信号平方项的Chirp-Z变换谱进行分析实现载频的精确估计,并提出了通过功率谱得到成形脉冲绝对值归一化波形的新方法,有效避免载频对根升余弦脉冲滚降系数估计的影响;其次对其包络谱进行分析,明确了信号包络谱在符号速率整数倍处出现明显谱线,得到符号周期的精确估计值,并结合功率谱分析中对成形脉冲归一化波形的估计,首次引入波形相似度衡量指标对滚降系数实现估计;最后根据周期调制信号模型,创新性地设计并构建了信号的动态延迟分段观测矩阵,分析不同延迟量情况下信号根升余弦脉冲基本波形的分段情况,利用所提出的改进的奇异值比谱实现对信号接收延迟的精确估计。仿真表明,本文方法具备较高的参数估计精度。To address the challenge of estimating key parameters of a root-raised cosine pulse-shaped Binary Phase Shift Keying(BPSK)signal in non-cooperative communication,the signal is innovatively modeled as a periodic modulation signal.A necessary analysis of the singular value decomposition results of the segmented observation matrix for the periodic modulation signal was conducted,clarifying the structural characteristics of singular value decomposition in both mono-component and multi-component cases.Based on this analysis and leveraging the characteristics of the signal itself,new methods were proposed for estimating key parameters such as symbol rate,carrier frequency,roll-off coefficient,and delay.First,by analyzing the power spectrum and its histogram of the received signal and utilizing the constant noise power spectrum,a rough estimation of the symbol rate and carrier frequency of the signal was achieved.Based on this,the Chirp-Z transform spectrum of the squared signal was analyzed to obtain a more precise carrier frequency estimate.A novel approach was introduced to obtain the normalized waveform of the root-raised cosine pulse by utilizing the power spectrum of the signal,effectively eliminating the influence of the carrier frequency on the estimation of the roll-off coefficient estimation.Second,an analysis of the envelope spectrum revealed distinct spectral lines at integer multiples of the symbol rate,enabling an accurate estimate of the symbol period.Waveform similarity measurement indicators combined with the estimation of the normalized waveform of the root-raised cosine pulse were introduced to estimate the roll-off coefficient for the first time.Finally,based on the periodic modulation signal model,a dynamic delay-segmented observation matrix was designed to analyze the segmentation of the basic waveform of the root-raised cosine pulse under different delay conditions.The proposed improved singular value ratio spectrum was then employed to achieve an accurate estimation of the signal reception delay.

关 键 词：根升余弦脉冲 二进制相移键控 参数估计 功率谱 包络谱 动态延迟分段观测矩阵 奇异值比谱 

分 类 号：TN911.72[电子电信—通信与信息系统]