基于I-Rife算法的突发扩频信号捕获系统设计

摘要

为了提高突发扩频通信每帧数据的传输利用率,节省捕获时间,设计基于I-Rife算法的突发扩频信号捕获系统.本系统主要分为粗捕获单元和细捕获单元,粗捕获单元通过匹配滤波器捕获码相位和多普勒频率粗估计值,细捕获单元通过I-Rife算法对多普勒频率进行精确估计.研究结果表明:在系统捕获多普勒频率的过程中,I-Rife算法比DFT直接谱估计算法和Rife算法具有更好的频率估计精度和全频段更稳定的频率估计性能;在系统要求的频率精度内,I-Rife算法使用了比DFT直接谱估计算法更少的FFT运算点数,达到了提高数据传输利用率和减少捕获时间的目的,更适合工程应用.%In order to improve the data transmission efficiency of spread spectrum signal per frame and save the capture time, the design of burst spread spectrum signal acquisition system based on I-Rife algorithm was proposed. This system mainly consisted of coarse acquisition unit and fine acquisition unit. The coarse acquisition unit captured the code phase and estimated the Doppler frequency value by the matched filter. Further the fine acquisition unit accurately estimated the Doppler frequency through the I-Rife algorithm. The results show that the proposed method can obtain precise frequency estimation and stable performance in full-band during the process of capturing Doppler frequency. In the requirement of the constant frequency accuracy, the transmission efficiency is improved and the capture time is reduced by the I-Rife algorithm, which uses fewer FFT computation points than DFT direct spectral estimation algorithm, which makes it more suitable for the engineering applications.