针对卫星通信中调制方式不断向高阶发展的情况,提出了一种对高阶数字调相信号的调制方式自动识别算法.该算法利用四阶以及更高阶的信号累积量和高阶信号的相位分布特征来提取出信号的特征参数,对QPSK、8PSK、16APSK和32 APSK四种调制方式进行了有效区分.给出了接收信号的处理流程图,并对算法进行了仿真.理论和仿真结果都表明,这种算法对信号的相位偏差具有不变性,同时对加性高斯噪声也不敏感,具有一定的稳健性,在特定的数据长度和较低信噪比条件下,可得到很高的识别率(>95%).%To investigate the automatic modulation recognition of high-order digital phase modulated signals widely used in satellite communication currently, such as QPSK,8PSK, 16APSK and 32APSK, this paper proposed an automatic recognition algorithm of digital phase modulated signals based on higher-order cumulants of signals and the characteristic of the phase' s distribution. The algorithm could recognize the modulation of QPSK, 8PSK, 16APSK and 32APSK with efficiency. It was invariant with respect to the difference of amplitude and phase, it was robust and usable. Simulation results prove the validity of the algorithm in low SNR environment. Computer simulations show that the application of this algorithm with a specified sample size results in high probability of correct identification ( ＞95％ ).
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