Noise-Domain Non-Orthogonal Multiple Access for Three Users

Abstract: In this study, we propose a novel three-user noise-domain non-orthogonal multiple access (ND-NOMA) scheme by introducing the correlation as a new dimension besides mean and variance quantities used in two-user ND-NOMA. The new three-user ND-NOMA scheme includes both uplink and downlink scenarios, with detectors designed to decode the information embedded in mean, variance, and correlation. Our theoretical analysis and simulation results under Rician fading channels show that the proposed system is capable of achieving promising bit error rate (BER) performance while preserving the low power and low complexity advantages of ND-NOMA. This new ND-NOMA design enables simultaneous communication among three users using different dimensions, paving the way for scalable multi-user communication in noise-domain systems and in the Internet-of-things (IoT) environments.