Abstract:In HF communication, the signals suffer from the effect of delay spread, time-varying interference and additive Gaussian noise. The performance of conventional differential demodulator is very poor in bad HF channel. A novel frequency domain differential demodulator is proposed which employs blind phase estimation to cancel the effect of phase error caused by delay spread. Its performance is studied through simulation in bad HF channel, and comparing with the conventional differential demodulator is described. Simulation results show that the proposed technique outperforms conventional differential demodulators in performance of transmission over the fast fading HF channel.