Impact of User Pairing on 5G Nonorthogonal Multiple-Access Downlink Transmissions
Impact of User Pairing on 5G Nonorthogonal Multiple-Access Downlink Transmissions
复制标题
用户配对对5G非正交多址下行传输的影响
DOI：
10.1109/tvt.2015.2480766
复制
发表时间：
2016-08-01
影响因子：
6.8
通讯作者：
Poor, H. Vincent
中科院分区：
文献类型：
--
作者：
Ding, Zhiguo;Fan, Pingzhi;Poor, H. Vincent
非正交多址接入（NOMA）代表了传统正交多址接入（MA）概念的范式转变，并且已被认为是第五代移动的网络的关键使能技术之一。本文研究了用户配对对两种NOMA系统性能的影响，NOMA与固定功率分配（F-NOMA）和认知无线电启发NOMA（CR-NOMA）的特点。对于F-NOMA，分析和数值结果表明，F-NOMA可以提供比正交MA更大的和速率，并且通过选择信道条件更特殊的用户可以进一步扩大F-NOMA相对于传统MA的性能增益。对于CR-NOMA，可以保证具有较差信道条件的用户的服务质量（QoS），因为分配给其他用户的发射功率遵循认知无线电网络的概念被约束。由于这种约束，CR-NOMA表现出与F-NOMA不同的行为。例如，对于具有最佳信道条件的用户，CR-NOMA优选将其与具有第二佳信道条件的用户配对，而具有最差信道条件的用户由F-NOMA优选。
Nonorthogonal multiple access (NOMA) represents a paradigm shift from conventional orthogonal multiple-access (MA) concepts and has been recognized as one of the key enabling technologies for fifth-generation mobile networks. In this paper, the impact of user pairing on the performance of two NOMA systems, i.e., NOMA with fixed power allocation (F-NOMA) and cognitive-radio-inspired NOMA (CR-NOMA), is characterized. For F-NOMA, both analytical and numerical results are provided to demonstrate that F-NOMA can offer a larger sum rate than orthogonal MA, and the performance gain of F-NOMA over conventional MA can be further enlarged by selecting users whose channel conditions are more distinctive. For CR-NOMA, the quality of service (QoS) for users with poorer channel conditions can be guaranteed since the transmit power allocated to other users is constrained following the concept of cognitive radio networks. Because of this constraint, CR-NOMA exhibits a different behavior compared with F-NOMA. For example, for the user with the best channel condition, CR-NOMA prefers to pair it with the user with the second best channel condition, whereas the user with the worst channel condition is preferred by F-NOMA.