On the Performance of NOMA Systems Over α-F Channels With Beam Misalignment

This letter investigates the performance of non-orthogonal multiple access (NOMA) systems over the $\alpha $ - $\mathcal {F}$ channels with beam misalignment, considering imperfect successive interference cancelation. Firstly, a new and exact expression is derived for the probability density function (PDF) of the instantaneous signal-to-noise ratio of an arbitrary NOMA user. The PDF is used to find the exact pairwise error probability (PEP) and its asymptotic counterpart. Furthermore, the achievable theoretical diversity gains and the bit error rate union bound are analyzed. Monte Carlo simulation results are presented to support the derived analytical expressions and provide valuable insights into each user’s error rate performance.