卫星测控侦察中相位编码信号的调制识别

针对卫星测控链路中常用的数字调相信号BPSK、QPSK、OQPSK（偏移QPSK）和UQPSK（非平衡QPSK）的调制识别问题，提出了基于二阶矩和相位差统计特性的分类算法。该方法首先以二倍码速率对复基带信号进行采样，然后利用能量归一化的二阶矩的模和相邻样点相位差绝对值的统计特性，分两个等级实现对这四种信号的分类。分析了载频偏移、相位误差以及成形脉冲对分类算法性能的影响，并通过计算机仿真验证了算法的有效性。

Algorithm of Modulation Classification of PSK Signals in Reconnaissance of TTC

To investigate the automatic modulation recognition of Phase Shift Keying(PSK) signals widely used in TTC(Tracking,Telemetry and Control) of satellite links,such as BPSK,QPSK,OQPSK(Offset QPSK),and UQPSK(Unbalanced QPSK),an algorithm based on second order moment and statistic of phase differences is proposed.First,the received baseband complex signal is sampled with a double code rate.Then the modulus of second order moment,which is normalized with the signal power,and the statistic of phase differences of adjacent samples are used to classify the four signals in a hierarchical scheme.The effects of carrier frequency offset,carrier phase error and transmitter pulse shape on the performance of the algorithm are analyzed.Computer simulations show the efficiency of the proposed classification algorithm.