Performance Analysis of High-Dimensional NOMA System with In-Phase/ Quadrature Index Modulation

In this paper, a Non-orthogonal multiple access (NOMA) system based on High-Dimensional signals with In-Phase/Quadrature Index Modulation (HD-IQ-IM-NOMA) is proposed. At the transmitter, two users with the high-dimensional signal constellations are separated their coordinate values into two parts, which are respectively mapped to the active in-phase component subcarriers and the active quadrature component subcarriers in each OFDM subblock. Further, different transmit powers are allocated to the high-dimensional modulated signals of two users, and then superimposed by the OFDM subcarrier module to form a NOMA transmit signal. At the receiver, the maximum likelihood (ML) and successive interference cancellation (SIC) detection methods are considered. The simulation results demonstrate that the proposed scheme exhibits superior error performance compared to the traditional IM-NOMA systems.