一种有效的水声通信多普勒处理方法

An efficient Doppler processor for underwater acoustic communications

在水声通信中,由于发射和接收平台之间的相对运动,多普勒频移是无法避免的。多普勒频移使信号频率和相位发生变化,降低载波估计的精度,造成自适应均衡器的发散,使整个系统的性能下降。文中设计了一种应用于水声多载波相干调制系统的多普勒处理方法,采用块估计和线性插值以抵消多普勒频移的影响。仿真结果表明,该方法能有效地抵消多普勒频移对多载波相干调制系统的影响。在信噪比为-10dB、数据率为100bit/s的条件下,系统允许相对运动速度可达到±10m/s。

Doppler shift is unavoidable in underwater acoustic communications because of relative moving between the transmitter and the receiver. Doppler shifts change received signal frequencies and phases, decrease accuracy of carrier frequencies estimation and result in divergence, presenting serious effect on system performance. An efficient Doppler processor applied to an acoustic multicarrier coherent modulation system has been designed. A block Doppler estimation technique and interpolation are used to remove Doppler shift. Simulation results show that the method can efficiently compensate for the Doppler effects on multicarrier coherent modulation systems. Relative velocities up to ±10m/s can be tolerated at 100bit/s and signal-to-noise ratio of-10dB.