This research presents an enhanced performance analysis process for the power domains of downlink-NOMA systems for vehicular communication over Rayleigh fading channels. We derived exact closed-form expressions of outage probability (OP), bit error rate (BER), outage capacity (OC), and average channel capacity (AVC) by using binary phase-shift keying (BPSK) modulation. All channel parameters required for downlink-NOMA system performance analysis were combined. The theoretical and simulation results perfectly confirmed one another. The obtained results were then compared with results from the literature, based on similar parameters. It was found that the proposed system increased the performance by 34 times for OP at SNR=15 dB, 92% and 22% for BER at SNR=24 dB, and 59% for AVC at SNR=30 dB. Finally, this study introduces exact solutions that will greatly accelerate NOMA system analysis by exploiting information in the existing database for analytical design processes based on communication theory.

这项研究提出了一种增强的性能分析过程，用于下行链路 NOMA 系统的功率域，用于通过瑞利衰落信道进行车辆通信。我们通过使用二进制相移键控 (BPSK) 调制导出了中断概率 (OP)、误码率 (BER)、中断容量 (OC) 和平均信道容量 (AVC) 的精确封闭式表达式。下行链路-NOMA 系统性能分析所需的所有信道参数都被组合起来。理论和仿真结果完美地相互印证。然后根据相似的参数将获得的结果与文献中的结果进行比较。发现所提出的系统在 SNR=15 dB 时将 OP 的性能提高了 34 倍，在 SNR=24 dB 时将 BER 提高了 92% 和 22%，在 SNR=30 dB 时将 AVC 提高了 59%。最后，