A new modulation technique for Doppler compensation in frequency-dispersive channels

Abstract

A new modulation technique for the time-frequency dispersive channel is considered. The waveform construction, called Frequency-Domain Multiplexing with a Frequency-Domain Cyclic Prefix (FDM-FDCP) efficiently corrects for the Doppler spread introduced by the channel. The mathematical foundations behind this construction are described and efficient algorithms presented to modulate and demodulate information symbols. It is found that for channels with a high Doppler spread and a low delay spread, the construction can sustain good performance in terms of low SER and minimal overhead, whereas OFDM is strictly worse. This shows that, in rapidly time-varying time-frequency dispersive channels, general time-frequency signaling schemes (FDM-FDCP being an example) may outperform OFDM or other waveform constructions designed for multipath channels with low mobility.