Beyond DVB-S2X: Faster-Than-Nyquist Signaling With Linear Precoding

Faster-than-Nyquist (FTN) signaling with linear precoding is investigated as a potential technique to transcend digital video broadcasting-satellite-second generation extension (DVB-S2X). Combining cyclic prefix (CP), cyclic suffix (CS) and discrete Fourier transform (DFT) with existing linear precoding algorithms, such as G-to-minus-half (GTMH) precoding (GTMHP), the CPS-GTMH-DFTP algorithm is proposed to eliminate inter-symbol interference (ISI) for FTN signaling. By comparison with most existing algorithms, our proposed CPS-GTMH-DFTP algorithm requires much lower implementation complexity. Specifically, only two multipliers and the corresponding fast Fourier transform (FFT)/inverse fast Fourier transform (IFFT) operations are required with the proposed CPS-GTMH-DFTP algorithm, which makes our proposed algorithm more suitable for practical implementation. Furthermore, the CPS-GTMH-DFTP algorithm has better bit error rate (BER) performance than most existing precoding algorithms. Simulation results show that even when the time acceleration parameter and roll-off factor equal to 0.75 and 0.35 respectively, our proposed CPS-GTMH-DFTP algorithm can still approach the BER performance of the ISI-free Nyquist signaling for all the modulation types adopted in DVB-S2X. More precisely, with 256-amplitude phase shift keying (APSK), the BER performance degradation is almost 0.03 and 0.01 dB in uncoded and coded FTN systems respectively. As far as we know, with regard to low complexity ISI elimination algorithms for FTN signaling, this is the first time to achieve such excellent performance with a time acceleration parameter 0.75 and a practical roll-off factor 0.35.