An Fourier Transform-based Implementation of Multicarrier Faster-than-Nyquist Signaling System

Multicarrier faster-than-Nyquist (MFTN) is a spectral efficient modulation scheme for future communication systems. However, since MFTN relies on the time interval packing of adjacent symbols/pulses and frequency spacing packing between adjacent subcarriers, the subcarriers are not orthogonal to each other anymore, and which results in the efficient implementation of MFTN signaling system a major challenge in practical applications. In this paper, we propose an efficient fast Fourier transform (FFT)-based implementation of MFTN signaling system. The proposed scheme is feasible when the subcarriers in MFTN are placed by a fraction of the orthogonal subcarrier spacing. By exploiting multiple parallel FFT blocks and combining the phase rotated versions of the FFT outputs, the MFTN signaling system can be implemented with substantially reduced computational complexity than conventional scheme, i.e., the direct implementation.