Spectrum Efficient GFDM Based on Faster Than Nyquist Signaling

Abstract

Future mobile communication system will provide high data rates for a miscellany of new applications. Spectrum efficiency is a key performance indicator that must be considerably improved for the beyond 5G networks. In this paper, a new approach to increase the waveform spectrum efficiency is investigated. This novel schemes combines the faster-thanNyquist signaling with generalized frequency division multiplexing, resulting in a scheme that can hold the main benefits of this innovative waveform with the high spectral efficiency gain. The scheme proposed in this paper abandons the orthogonality principle for the time-frequency grid, reducing the spacing between the subcarriers. The reduced subcarrier spacing does not affect the minimum distance among the transmitted sequences, if the Mazo’s limit is respected and the data can be recovered by a non-linear receiver without bit error penalties. In this paper, maximum likelihood receiver will be used for a proof of conception, showing that the bit error performance is equivalent to the one achieved by orthogonal systems. The system will be integrated with a forward error control scheme, showing that the proposed scheme can be fully integrated with modern error control codes, while improving the spectrum efficiency by 20%.