摘要： 在水声通信系统中,大多数多普勒频移因子估计方法未能很好地处理相对运动速度较高时计算复杂度与估计精度之间的关系。针对该情况,提出基于快速傅里叶变换(FFT)测频和模糊度函数的联合估计方法。通过FFT对单频脉冲信号进行测频以确定多普勒频移因子的初步估计范围,再使用模糊度函数法在该范围内进行搜索,得到精确的多普勒频移因子。仿真结果表明,当信噪比大于-20 dB时,该方法在相对运动速度为-60 m/s~60 m/s时能保持高于0.02％的估计精度,且与单独使用模糊度函数的估计方法相比,具有较低的计算复杂度。

关键词: 水声通信, 普勒频移因子, 糊度函数, 速傅里叶变换测频, 频脉冲信号

Abstract: In underwater acoustic communication systems,most of the Doppler shift factor estimation methods cannot deal with the relationship between computational complexity and estimation accuracy under high relative motion speed.In view of this,this paper proposes a Doppler shift factor estimation method based on the Fast Fourier Transformation(FFT) frequency measurement and ambiguity function.First,the range of Doppler shift factor is determined in a small range by using FFT on the single-frequency pulse signal.Then,Doppler shift factor is estimated by using ambiguity function method in the range of determination.Simulation results show that estimation accuracy maintains higher than 0.02% when SNR is greater than -20 dB and relative motion speed is -60 m/s to 60 m/s.Computational complexity is significantly reduced compared with the ambiguity function method.

Key words: underwater acoustic communication, oppler shift factor, mbiguity function, Fast Fourier Transform(FFT) frequency measurement, single-frequency pulse signal

中图分类号: 

• TN911.7