Improved Frequency Domain Differential Demodulation for Fast Fading HF Channels

The bit error rate (BER) of MDPSK-OFDM in frequency domain over fading HF channels is evaluated, and the optimum value of subcarrier number is given and the upper and lower bound of BER is obtained. The convention differential demodulation scheme is sensitive to the value of subcarrier number in time-variant multipath channel. Improved frequency domain differential demodulation (FDDD) scheme for fast fading HF channel is proposed. In addition, the simulation results show that our proposed scheme is superior to the conventional differential demodulation technique at fast fading HF channel.