脉内相位编码信号的识别与码序恢复

Recognition and Symbol Sequence Recovery of PSK Signals on Pulse

为了提高低信噪比(SNR)下对雷达脉内相位编码(PSK)信号的处理能力,对传统的相位差分法进行了改进,并利用该方法对PSK信号进行了识别与码元序列的恢复。根据PSK信号的特性,结合滤波、数字变频和高阶差分来减小噪声对相位的影响,提高了相位差分法的抗噪性。对相位差分序列归一化后,先进行码元宽度的精确估计,再由码元关系去除伪跳变点。最后通过一系列的特征提取,实现了PSK信号的综合处理。仿真结果表明,所提算法在低信噪比下性能良好,具有很高的工程应用价值。

To enhance the processing ability of Phase Shift Keying（PSK） signals on radar pulses under lowSignal-to-Noise Ratio （SNR）, the traditional phase difference method is improved. The improved methodis used for modulation recognition and symbol sequence recovery of PSK signals. According to characteristics of PSK signals, the filter, digital frequency conversion and high order difference are combined to reduce the influence of noise on phase,which improves the ability of immunity to noise for phase differencemethod. After phase difference sequence is normalized, the accurate estimation of the symbol width is obtained firstly. Then, the relationship between symbols is used to remove false symbol jump. Through a series of feature extraction, the comprehensive processing of PSK signals is realized finally. The results ofsimulation show that the proposed algorithm has a good performance under low SNR and also high value ofengineering application.