已发表的调制识别算法大多基于单一特征参数,识别种类较少,且往往很难在实际系统中布署.提出了一种基于谱线-高阶累积量的数字调制识别算法,该算法利用载波频率估计、符号速率估计、定时恢复、噪声功率估计等前处理手段,结合信号功率谱、二次方谱、四次方谱中的离散谱线和四阶归一化高阶累积量,可识别 2ASK、4ASK、8ASK、2FSK、4FSK、8FSK、BPSK、QPSK、8PSK、OQPSK、MSK、16QAM、32QAM、64QAM、128QAM、256QAM 16 种数字调制信号.基于该算法,设计并实现了一种数字调制识别处理系统,可实时识别上述 16 种调制信号.结果表明,该实时系统对大部分调制信号的识别准确率可达到 99%以上,对 8PSK、32QAM、128QAM等调制信号的识别准确率可达到94%以上.
Most of the published modulation recognition algorithms are based on a single feature parameter,with limited recognition types and often difficult to deploy in practical systems.Therefore,a digital modulation recognition algorithm based on spectral line high-order cumulant is proposed.The algorithm utilizes pre-processing methods such as carrier frequency estimation,symbol rate estimation,timing recovery,and noise power estimation,combined with discrete spectral lines and fourth-order normalized high-order cumulants in signal power spectrum,quadratic spectrum,and fourth-order spectrum.It can recognize 2ASK,4ASK,8ASK,2FSK,4FSK,8FSK,BPSK,QPSK,8PSK,OQPSK,MSK,16QAM,32QAM,64QAM,etc There are 16 types of digital modulation signals,including 128QAM and 256QAM.Based on this algorithm,a digital modulation recognition processing system was designed and implemented,which can recognize the 16 modulation signals mentioned above in real time.The results show that the real-time system can achieve recognition accuracy of 99%or above for most modulation signals,and recognition accuracy of 94%or above for modulation signals such as 8PSK,32QAM,and 128QAM.