Modeling and estimation of the space-time varying channels

On the basis of BELLHOP model, the influence of transmitter’s active travel on underwater acoustic channel is emphasized, and a BELLHOP-based space-time channel model is established. According to the characteristics of CW pulse signal, LFM pulse signal and HFM pulse signal, and inspired by the conventional Doppler estimation method in communication, this paper improves them and estimates the Doppler factor in combination with the established model. Simulation results show that the performance of Doppler factor estimation of HFM signal is better. For the estimation of delay and attenuation coefficient, LFM signal has the best energy aggregation characteristic in fractional domain, and the position and amplitude of correlation peak are obtained to estimate the delay and attenuation factor.