Joint Precoding and Pre-equalization for Faster-Than-Nyquist Transmission over Multipath Fading Channels

Faster-than-Nyquist signaling (FTNS) has emerged as a promising technique to increase communication capacity in bandwidth-limited channels. However, the presence of FTN-induced inter-symbol interference (FTN-ISI) received observations, is detrimental channel estimation (CE) and data detection terms computational complexity performance. This paper copes with these problems by incorporating linear pre-equalization (LPE) composite precoding formed spectral Tomlinson-Harashima (THP), into FTNS. Specifically, LPE completely pre-equalizes FTN-ISI, while resolves LPE-caused signal broadening introducing proper artificial ISI, which pre-equalized THP. Channel-induced only ISI component estimated equalized using classical frequency-domain low-complexity schemes. We show that there are four advantages LPE-aided CE over designed for FTN transmissions without FTN-ISI pre-equalization, namely lower pilot overhead, simpler yet optimal sequence design, mean-squared error CE, more robust against FTN-ISI. Simulation results our scheme improves performance detection, compared existing equalization