Performance of Time and Frequency Compression of Faster-than-Nyquist Signaling in Frequency-Selective Fading Channels

This paper investigates the block error rate (BLER) performance of time and frequency domain compression for Faster-than-Nyquist (FTN) signaling in frequency-selective fading channels. In this paper, we use FTN mapping method in which FTN symbols are mapped onto orthogonal frequency division multiplexing (OFDM)/offset quadrature amplitude modulation (OQAM) symbol positions at a transmitter and a turbo soft interference canceller (SIC) used for an antenna-diversity receiver. Computer simulation results show that frequency domain compression decreases the required average received signal-to-noise power ratio satisfying the target average BLER compared to time domain compression when the root mean square (r.m.s.) delay spread is longer than approximately 1.5 mu s. We also show, however, that the FTN signaling with time domain compression achieves a higher frequency efficiency compared to that with frequency domain compression when the r.m.s. delay spread is less than 1.5 mu s.