Power-Domain-Multiplexed Precoded Faster-Than-Nyquist Signaling for NOMA Downlink

In this paper, we propose a novel precoded faster-than-Nyquist (FTN) signaling scheme with power-domain-multiplexing in non-orthogonal multiple access (NOMA) down-link for tapping the joint benefits of high spectral efficiency and simultaneous multiuser connectivity. Non-orthogonality is introduced in both the symbol-interval (time) domain as well as in the multiple-access (power) domain to achieve a flexible resource allocation. Eigendecomposition of the FTN-specific intersymbol interference (ISI) matrix is used to achieve efficient cancellation of ISI, while successive interference cancellation is used to elim-inate multiuser interference induced by NOMA. We derive the achievable analytical rate bound and demonstrate the numerical results of the bit error rate performance for the proposed scheme.