Design and Performance Analysis of Cooperative NOMA With Coordinated Direct and Relay Transmission
Design and Performance Analysis of Cooperative NOMA With Coordinated Direct and Relay Transmission
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DOI：
10.1109/access.2019.2920669
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发表时间：
2019-06
期刊：
影响因子：
3.9
通讯作者：
Mengqi Yang;Jian Chen;Long Yang;Lu Lv;Bingtao He;Boyang Liu
中科院分区：
文献类型：
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作者：
Mengqi Yang;Jian Chen;Long Yang;Lu Lv;Bingtao He;Boyang Liu
本文研究了由基站（BS）、小区中心用户（CCU）、小区边缘用户（CEU）和一组半双工中继组成的非正交多址网络中的协调直接中继传输（CDRT）。在每次传输过程中，BS直接将信息发送到CCU，并通过其中一个继电器将信息发送到CEU。为了提高传输可靠性，设计了一种新的动态检测CDRT （DD-CDRT）策略，充分利用可用侧信息消除用户间干扰。在DD-CDRT策略的基础上，我们进一步提出了一种中继选择方案，在保证CCU可靠接收的同时，最大限度地提高CCU的成功解码概率。为了评估我们的设计，为每个用户导出了精确和渐近的中断概率。结果表明，CEU可实现的分集顺序等于继电器的个数。同时，CCU实现了一个整体的多样性秩序。具体来说，当系统和速率较小或继电器数量足够大时，CCU的停电性能可以接近无干扰情况的性能。最后，给出了数值结果来验证理论分析，并展示了采用所提出的中继选择方案的DD-CDRT策略的优势。
This paper studies the coordinated direct and relay transmission (CDRT) in the non-orthogonal multiple access network, which consists of a base station (BS), a cell-center user (CCU), a cell edge user (CEU), and a group of half-duplex relays. During each transmission, the BS sends information to the CCU directly and to the CEU with the help of one of the relays. To improve the transmission reliability, a novel dynamic detection CDRT (DD-CDRT) strategy is designed, which fully exploits the available side information to eliminate the inter-user interference. Based on the DD-CDRT strategy, we further propose a relay selection scheme which maximizes the CCU’s successful decoding probability with guaranteeing the reliable reception of the CEU. To evaluate our designs, exact and asymptotic outage probabilities are derived for each user. The results show that the achievable diversity order for the CEU is equal to the number of relays. Meanwhile, the CCU achieves a diversity order as one. Specifically, when the system sum rate is relatively small or the relay number is large enough, the outage performance of the CCU can approach the performance of the interference-free situation. Finally, the numerical results are presented to verify the theoretical analysis and to demonstrate the advantages of the DD-CDRT strategy using the proposed relay selection scheme.