共信道时频重叠的数字信号调制识别方法

摘要

为解决由多信号时频重叠导致的制式识别困难的问题,提出高阶累积量和瞬时特征值联合识别的方法.根据不同信号高阶累积量和瞬时幅度的差异,从中提取5个特征参数;在此基础上利用决策树对由2ASK、4ASK、QPSK和8PSK这4种数字信号任意组合而成的10种双信号进行分类.计算机仿真结果表明,该算法可以在较低的信噪比下,有效地对时频重叠数字双信号进行分类识别,与其它方法进行比较,验证了该算法可以识别更多的信号种类,具有更高的识别率.%To solve the problem of modulation recognition caused by the overlap of multi-signal time-frequency,a method of associative recognition of higher order cumulant and instantaneous characteristic value was proposed.Five feature parameters were withdrawn according to the differences of higher order cumulants and instantaneous amplitudes from different signals.Under this condition,ten kinds of dual-signal arbitrarily combined by 2ASK,4ASK,QPSK and 8PSK were classified using the decision tree.The computer simulation results show that the dual-signal of time-frequency overlapping can be effectively classified and recognized using the proposed algorithm at a low signal-to-noise ratio.Compared with other methods,it is verified that the proposed algorithm can recognize more signals and it has higher recognition rate.