In this paper, a novel jointly adaptive transmission strategy for buffer-aided multiple-relay non-orthogonal multiple access (NOMA) networks is proposed. By leveraging time diversity brought by the data storage buffer, and multiple relays’ beamforming gains, the source node broadcasts data in the first hop and all relays perform distributed beamforming to transmit information to users with NOMA in the second hop. Our focus is on maximizing the average network throughput (ANT) by jointly optimizing the mode selection, power and rate allocation at the source node, as well as the rate allocation and distributed beamforming coefficients at the relays along the time. As a solution to this complex problem, we propose an online scheduling scheme, which first adopts the Lyapunov optimization methodology to convert the ANT maximization problem into the drift-plus-penalty function minimization problem at each time slot. Secondly, focusing on the non-convexity of the transformed problem at each time slot, a novel two-loop algorithm is proposed as an effective solution. Extensive performance evaluation results have revealed the superiority of the proposed scheme as compared to other benchmark access schemes, namely, buffer-aided single relay NOMA, maximum ratio transmission based NOMA and buffer-aided time division multiple access schemes.

中文翻译：

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缓冲区辅助多中继 NOMA 网络的联合自适应分布式波束成形和资源分配


本文提出了一种用于缓冲辅助多中继非正交多址（NOMA）网络的新型联合自适应传输策略。利用数据存储缓冲区带来的时间分集和多个中继的波束成形增益，源节点在第一跳广播数据，所有中继执行分布式波束成形，以在第二跳向具有NOMA的用户传输信息。我们的重点是通过联合优化源节点的模式选择、功率和速率分配以及中继器的速率分配和分布式波束成形系数来最大化平均网络吞吐量（ANT）。作为这个复杂问题的解决方案，我们提出了一种在线调度方案，该方案首先采用Lyapunov优化方法将ANT最大化问题转化为每个时隙的漂移加罚函数最小化问题。其次，针对变换问题在每个时隙的非凸性，提出了一种新的双环算法作为有效的解决方案。广泛的性能评估结果表明，与其他基准接入方案（即缓冲辅助单中继NOMA、基于最大比率传输的NOMA和缓冲辅助时分多址方案）相比，所提出的方案具有优越性。