一种新的相位编码信号识别方法

A new recognition method for phase-shift keying signals

针对现有的许多PSK信号识别方法中,低信噪比与小计算量不能同时兼顾的问题,提出了一种新的PSK信号识别方法.首先估计接收信号的功率谱并对其进行平滑处理,以3 dB带宽内功率谱的重心作为信号的载频估计,并利用估计值将接收信号下变频至基带,然后根据基带信号虚部和实部累加输出波形的幅度互补且其拐点位置恰与相位跳变点相对应的特性,结合彼此的优势,辨识PSK信号.这种方法运算量小,易于实现,且能适用于较低信噪比的情况.仿真结果验证了算法的有效性.

A new phase-shift keying （PSK） signal recognition method was developed for low signal to noise ratio （SNR） environments, and it significantly decreases the calculations required in PSK signal recognition compared to existing methods. It first estimates the power spectrum of received signals and smoothes the results. Then it breaks the peaks of signal strength of the power spectrum into 3 dB slices in order to estimate carrier frequency. The received signal is down converted to the baseband using this estimated value. Finally, by considering the amplitudes of cumulative outputs of the baseband signal＇s imaginary parts and real parts to be complementary, and its inflexion point to be just a jump point in its phase, the PSK signal can be identified. This method is easy to calculate and implement, and can be applied in low SNR situations. Simulations showed the validity of the algorithm.