Successive User Relaying in Cooperative NOMA System
Successive User Relaying in Cooperative NOMA System
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DOI：
10.1109/lwc.2019.2900013
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发表时间：
2019-06-01
影响因子：
6.3
通讯作者：
Leow, Chee Yen
中科院分区：
文献类型：
--
作者：
Liau, Qian Yu;Leow, Chee Yen
协作非正交多址接入（C-NOMA）系统中的用户中继可以提高系统的可靠性。然而，对于以半双工（HD）模式操作的用户，需要额外的带宽用于中继操作。这降低了C-NOMA系统的频谱效率。本文提出了一种连续用户中继（SR）来提高C-NOMA系统的频谱效率。在所提出的SR方案中，一对HD用户解码接收到的信号，并中继解码后的信号连续，以提高频谱效率。为了提高用户间中断性能的公平性，提出了一种新的功率分配因子优化算法。所提出的SR方案的性能上级现有的HD中继方案在C-NOMA系统和现有的SR在协作正交多址系统的中断概率和遍历和率。给出了该SR的中断概率和渐近遍历和速率的封闭表达式。
User relaying in cooperative non-orthogonal multiple access (C-NOMA) system is able to enhance reliability. However, for user operates in half-duplex (HD) mode, additional bandwidth is needed for relaying operation. This reduces spectral efficiency of C-NOMA system. This letter proposes a successive user relaying (SR) to improve the spectral efficiency of C-NOMA system. In the proposed SR scheme, a pair of HD users decode the received signal and relay the decoded signal successively to improve the spectral efficiency. A novel algorithm is proposed to optimize power split factor in order to improve fairness of outage performance between users. The performance of the proposed SR scheme is superior to existing HD relaying scheme in C-NOMA system and existing SR in cooperative orthogonal multiple access system in terms of outage probability and ergodic sum rate. The closed-form expressions of outage probability and asymptotic ergodic sum rate of proposed SR are also derived.