Coordinate Interleaved Faster-than-Nyquist Signaling

TL;DR

This paper introduces a novel FTN signaling method called CI-FTN that exploits ISI at the transmitter to enhance spectral efficiency with a low-complexity receiver, outperforming conventional methods.

Contribution

The paper proposes a new CI-FTN signaling technique that uses interleaving of BPSK components to create constructive ISI, along with a low-complexity detection algorithm.

Findings

CI-FTN improves spectral efficiency over Nyquist and traditional FTN.

The proposed detector effectively leverages constructive ISI.

Simulation results confirm performance gains of CI-FTN.

Abstract

Faster-than-Nyquist (FTN) signaling is an attractive transmission technique which accelerates data symbols beyond the Nyquist rate to improve the spectral efficiency; however, at the expense of higher computational complexity to remove the introduced intersymbol interference (ISI). In this work, we introduce a novel FTN signaling transmission technique, named coordinate interleaved FTN (CI-FTN) signaling that exploits the ISI at the transmitter to generate constructive interference for every pair of the counter-clockwise rotated binary phase shift keying (BPSK) data symbols. In particular, the proposed CI- FTN signaling interleaves the in-phase (I) and the quadrature (Q) components of the counter-clockwise rotated BPSK symbols to guarantee that every pair of consecutive symbols has the same sign, and hence, has constructive ISI. At the receiver, we propose a low-complexity detector that makes use of the constructive ISI introduced at the transmitter. Simulation results show the merits of the CI-FTN signaling and the proposed low-complexity detector compared to conventional Nyquist and FTN signaling.