Performance of Heterogeneous NOMA Networks in Impulsive Noise With Transmit Antenna Selection

This letter investigates the performance of multi-tier heterogeneous cellular networks (HCNs) with macro-and pico-base stations (MBS, PBS) employing non-orthogonal multiple access (NOMA) to improve spectral efficiency and achieve higher data rates for the sixth-generation (6G) wireless networks. Deployment in smart homes, grids, and industrial IoT is challenged by impulsive electromagnetic interference, rendering Gaussian noise-based analyses inadequate. Thus, this study uses stochastic geometry to compare HCN-NOMA performance under additive white Gaussian noise (AWGN) and impulsive noise (Im-N), highlighting variations in system behavior. A comparative analysis of OMA and NOMA under these noise conditions with closed form expressions for outage probability (OP) and asymptotic OP, throughput and energy efficiency using the transmit antenna selection (TAS) is presented, with performance measured by varying base station densities. NOMA outperforms OMA in both AWGN and Im-N scenarios, maximizing gains in specific signal-to-noise ratio (SNR) ranges and proving better for the users with poor channel condition in TAS with multiple transmit antennas.