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.

非正交多址（NOMA）在现代无线通信系统中至关重要，因为它支持高效的多址接入方案，允许多个用户共享相同的频谱资源，从而提高整体网络容量。多输入多输出 (MIMO) 技术在无线通信中至关重要，因为它利用多个天线来增强数据吞吐量、提高链路可靠性并减轻信号干扰，从而提高通信性能。MIMO 和 NOMA 的结合代表了一种变革性的协同作用，它利用了两种技术的优势，促进了无线网络的高效频谱利用、更高的数据速率和更高的可靠性。这使得它在第五代（5G）时代及以后尤其有价值。本文研究了 MIMO-NOMA 网络中基于多数的发射天线选择和最大比合并 (TAS-maj/MRC) 的性能。我们推导出 Nakagami- m衰落信道中二进制相移键控 (BPSK) 调制的精确误码率 (BER) 的封闭式表达式。此外，在高信噪比 (SNR) 区域获得渐近表达式，以进一步了解系统的 BER 行为。最后，我们通过仿真验证了分析结果的准确性。结果表明实现了多样性和代码增益。此外，随着接收天线数量的增加或信道条件的改善，BER 性能显着提高。