基于时频修正与波形变换的MFSK信号调制参数盲估计

Blind Estimation of Modulation Parameters of MFSK Signal Based on Time-frequency Modifying and Waveform Transforming

多进制频移键控(MFSK)信号被广泛应用于各种军用、民用通信系统中。针对其调制参数估计,现有的方法大多基于小波变换,但其存在抗噪性能差,参数不易选取等问题。通过对语图不确定原理的研究,该文提出一种语图逻辑"与"运算方法,并引入波形变换理论改善时频变换波形占空比,提高了估计算法的信噪比门限,完成低信噪比下MFSK信号调制参数的自适应盲估计。仿真表明,所提算法在抗噪声、频偏性能及参数选取鲁棒性上均优于现有常用算法,适合工程实践。

MFSK signal is widely used in military and civil communication systems. For the issues of its modulation parameters＇ estimation, wavelet transform theory is mostly adopted in current algorithms. However, the anti-noise performance is poor and parameters are difficult to choose. On the research of indeterminacy theory of spectrogram a strategy for spectrograms modifying is proposed and the waveform transforming theory is drawn into to upgrade the duty cycle. As the result, the anti-noise performance is improved and the self adaption blind parameter estimation is achieved. The simulation results indicate a better performance of proposed algorithm than current algorithms in anti-noise and frequency offset performance and robustness of parameters which makes it a better choice for engineering practice.