This work analyzes the performance of a downlink multi-user multiple-input multiple-output (MU-MIMO) non-orthogonal multiple access (NOMA) communications system. To reduce hardware complexity and exploit antenna diversity, we consider a transmit antenna selection (TAS) scheme and equal-gain combining (EGC) receivers. Further, we consider Weibull-distributed fading channels to account for non-linearities of the propagation medium and to cover, as special cases, important fading scenarios such as Rayleigh and exponential models. Performance metrics such as the outage probability (OP) and the average bit error rate (ABER) are derived in an exact manner. An asymptotic analysis for the OP and for the ABER is also carried out. Moreover, we obtain exact expressions for the probability density function (PDF) and the cumulative distribution function (CDF) of the end-to-end signal-to-noise ratio (SNR). Interestingly, our results indicate that, except for the first user (nearest user), in a high-SNR regime the ABER achieves a performance floor that depends solely on the user's power allocation coefficient and on the type of modulation, and not on the channel statistics or the amount of transmit and receive antennas. To the best of the authors' knowledge, no performance analyses have been reported in the literature for the considered scenario. The validity of all our expressions is confirmed via Monte-Carlo simulations.
翻译:这项工作分析了多用户多输入多输出(MU-MIMO)非垂直多输出(NOMA)通信系统的性能。 为了降低硬件复杂性和利用天线多样性, 我们考虑的是传输天线选择( TAS) 和平等增益组合接收器( EGC) 。 此外, 我们考虑的是 Weibull 分布式淡化渠道, 以说明传播介质的非线性, 并将其作为特殊案例, 包括诸如Rayleigh和指数模型等重要的淡化情景。 性能指标, 如超值概率(OP)和平均比特错误率(ABER), 以精确的方式产生。 为了降低硬件复杂性并利用天线多样性, 我们还考虑的是传输天线选择和天线( ATS) 的无症状分析。 此外, 我们对终端到终端信号到噪音比率( SNRI) 的概率功能分配( CDF) 的准确表达方式, 我们的结果表明, 除了第一个用户( 最接近的用户) 和平均比差率(ABER) 以高S 系统 接收到的系统 的图像格式( Abreviewalalal) 和最高级用户的图像分配速度( ) 度( ) 的图像) 度( ) 度( ) ) 度( ) 不取决于所有用户数据传输数据传输的图像( ) 水平( ) ) ) 的图像( ) 语言) 水平( 的计算值分配) 的计算, 水平( ) 水平( ) ) 水平( ) ) 的计算。