Non-Orthogonal Frequency-Division Multiplexing Based on Eigenvalue Decomposition

This paper proposes a novel ultra-dense non-orthogonal frequency-division multiplexing (NOFDM) transmission, where subcarrier spacing is set significantly lower than that of OFDM. Eigenvalue-decomposition-aided precoding is conceived for eliminating the detrimental effects of NOFDM-specific inter-carrier interference and correlated noises. The classic capacity formula is extended to that supporting our precoded NOFDM scheme. Optimal power allocation (PA) is developed for maximizing the derived capacity of the proposed scheme. In analytical and numerical results, we demonstrate that the proposed NOFDM scheme with optimal PA outperforms the conventional NOFDM and the classic OFDM schemes.