On the Performance of Network NOMA in Uplink CoMP Systems: A Stochastic Geometry Approach
On the Performance of Network NOMA in Uplink CoMP Systems: A Stochastic Geometry Approach
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DOI：
10.1109/tcomm.2019.2906307
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发表时间：
2019-07-01
影响因子：
8.3
通讯作者：
Dobre, Octavia A.
中科院分区：
文献类型：
--
作者：
Sun, Yanshi;Ding, Zhiguo;Dobre, Octavia A.
为了提高系统吞吐量，提出了一种用于上行链路协作多点传输（CoMP）的网络非正交多址接入（N-NOMA）技术。在所考虑的场景中，多个基站彼此协作以服务单个用户，称为CoMP用户，这与传统CoMP相同。然而，与传统CoMP不同，N-NOMA中的每个基站在以相同带宽服务CoMP用户的同时，机会主义地服务额外的用户，称为NOMA用户。CoMP用户通常位于远离基站的位置，而靠近基站的用户被调度为NOMA用户。因此，这两种用户的信道条件是非常不同的，这有利于NOMA的实现。与传统的基于正交多址的CoMP方案相比，多个基站只为单个CoMP用户提供服务，所提出的N-NOMA方案可以通过为额外的NOMA用户提供服务来支持更大的连接，并通过避免CoMP用户单独占用频谱来提高频谱效率。一个随机几何的方法被施加到考虑N-NOMA场景的泊松聚类过程建模，在此基础上有见地的封闭形式或准封闭形式的中断概率和遍历率的解析表达式。数值结果显示了分析结果的准确性，也证明了所提出的N-NOMA方案的上级性能。
To improve the system throughput, this paper proposes a network non-orthogonal multiple access (N-NOMA) technique for the uplink coordinated multi-point transmission (CoMP). In the considered scenario, multiple base stations collaborate with each other to serve a single user, referred to as the CoMP user, which is the same as for conventional CoMP. However, unlike conventional CoMP, each base station in N-NOMA opportunistically serves an extra user, referred to as the NOMA user, while serving the CoMP user at the same bandwidth. The CoMP user is typically located far from the base stations, whereas users close to the base stations are scheduled as NOMA users. Hence, the channel conditions of the two kinds of users are very distinctive, which facilitates the implementation of NOMA. Compared to the conventional orthogonal multiple access-based CoMP scheme, where multiple base stations serve a single CoMP user only, the proposed N-NOMA scheme can support larger connectivity by serving the extra NOMA users, and improve the spectral efficiency by avoiding the CoMP user solely occupying the spectrum. A stochastic geometry approach is applied to model the considered N-NOMA scenario as a Poisson cluster process, based on which insightful closed-form or quasi closed-form analytical expressions for outage probabilities and ergodic rates are obtained. Numerical results are presented to show the accuracy of the analytical results and also demonstrate the superior performance of the proposed N-NOMA scheme.