On Performance of NOMA-Empowered HCN: A Stochastic Geometry Approach Considering Imperfect SIC and CSI

In a multi-tier heterogeneous cellular network (HCN) with macro-base station (MBS) and pico-base station (PBS), non-orthogonal multiple access (NOMA) is used to boost spectral efficiency and achieve higher data rates in the sixth-generation wireless networks. This study investigates HCN-NOMA performance under practical consideration of imperfect successive interference cancellation (i-SIC) and imperfect channel state information (i-CSI) using stochastic geometry. This study compares OMA and NOMA, evaluating outage probability, asymptotic outage probability, system throughput, and energy efficiency for both perfect and i-SIC scenarios in multi-tier HCN. Despite i-SIC and i-CSI in NOMA, noticeable performance improvements of up to 57% are observed.