Performance analysis of majority-based transmit antenna selection and maximal ratio combining in MIMO-NOMA networks

Non-orthogonal multiple access (NOMA) is paramount in modern wireless communication systems since it enables efficient multiple access schemes, allowing multiple users to share the same spectrum resources and thus improving overall network capacity. Multiple-input multiple-output (MIMO) technology is crucial in wireless communication as it leverages multiple antennas to enhance data throughput, increase link reliability, and mitigate signal interference, resulting in improved communication performance. The combination of MIMO and NOMA represents a transformative synergy that harnesses the benefits of both technologies, facilitating efficient spectrum utilization, higher data rates, and improved reliability in wireless networks. This makes it particularly valuable in the fifth-generation (5G) era and beyond. This paper investigates the performance of majority-based transmit antenna selection and maximal ratio combining (TAS-maj/MRC) in MIMO-NOMA networks. We derive a closed-form expression for the exact bit error rate (BER) for binary phase shift keying (BPSK) modulation in Nakagami-m fading channels. Moreover, asymptotic expressions are obtained in the high signal-to-noise ratio (SNR) region to get further insight into the BER behavior of the system. Finally, we verify the analytical results’ accuracy through simulations. The results demonstrate that diversity and code gains are achieved. In addition, the BER performance is significantly improved as the number of receive antennas increases or channel condition enhances.