论文标题
上行链路和下行链路MIMO-NOMA与同时三角化
Uplink and Downlink MIMO-NOMA with Simultaneous Triangularization
论文作者
论文摘要
在本文中，我们考虑了两用户功率域多输入多输出（MIMO）非正交多访问（NOMA）系统的上行链路和下行链路预编码器设计。我们提出了新颖的上行链接和下链链路预编码和解码方案，这些方案通过将用户的Mimo-Noma通道分解为多个单单输入（SISO） - noma频道，通过同时三角形（ST）将用户的Mimo-Noma通道分解为多个单个单输出（SISO） - NOMA频道（ST）。拟议的ST MIMO-NOMA方案避免在发射器和接收器处的通道反转，并利用用户的MIMO通道的空空间，这对可达到的可实现的速率性能有益。我们表征了拟议的上行链路和下行链路ST MIMO-NOMA方案的最大千古可达到的速率区域，并将它们与各自的上限，基线MIMO-NOMA预编码方案以及正交多重访问（OMA）进行比较。我们的结果表明，所提出的方案的表现明显优于所考虑的基线MIMO-NOMA预编码方案和OMA，并且对于大多数渠道条件和用户速率而言，相应的上限差距很小。此外，我们表明，一种混合方案可以在拟议的上行链路和下行链路上的ST MIMO-NOMA和单用户MIMO之间进行时间共享，可以进一步提高性能。
In this paper, we consider the uplink and downlink precoder design for two-user power-domain multiple-input multiple-output (MIMO) non-orthogonal multiple access (NOMA) systems. We propose novel uplink and downlink precoding and decoding schemes that lower the decoding complexity at the receiver by decomposing the MIMO-NOMA channels of the users into multiple single-input single-output (SISO)-NOMA channels via simultaneous triangularization (ST) of the MIMO channels of the users and a low-complexity self-interference cancellation at the receiver. The proposed ST MIMO-NOMA schemes avoid channel inversion at transmitter and receiver and take advantage of the null spaces of the MIMO channels of the users, which is beneficial for the ergodic achievable rate performance. We characterize the maximum ergodic achievable rate regions of the proposed uplink and downlink ST MIMO-NOMA schemes, and compare them with respective upper bounds, baseline MIMO-NOMA precoding schemes, and orthogonal multiple access (OMA). Our results illustrate that the proposed schemes significantly outperform the considered baseline MIMO-NOMA precoding schemes and OMA, and have a small gap to the respective upper bounds for most channel conditions and user rates. Moreover, we show that a hybrid scheme, which performs time sharing between the proposed uplink and downlink ST MIMO-NOMA and single-user MIMO, can improve performance even further.
