In this letter, we propose a novel low-complexity user pairing (UP) and power allocation (PA) technique utilizing the compressive sensing (CS) theory for non-orthogonal multiple access (NOMA) systems. In the proposed scheme, we formulate the joint UP and PA optimization problem in NOMA systems as a relaxed sparse $l_{1}$ -norm problem, based on the fact that a limited, i.e., ‘sparse,’ number of users has to be paired among a large number of users over a dedicated resource block (RB). By exploiting this inherent sparsity property, we can obtain a near-optimal solution by relaxing the original NP-hard problem of joint UP and PA. Then, a CS technique is proposed to find a solution for the relaxed problem. Simulation results validate the effectiveness of our proposed idea regarding the sum-rate and the reduced complexity compared to the state-of-the-art schemes.

中文翻译：

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NOMA 系统中具有压缩感知的联合用户配对和功率分配

在这封信中，我们提出了一种新颖的低复杂度用户配对 (UP) 和功率分配 (PA) 技术，利用非正交多址 (NOMA) 系统的压缩感知 (CS) 理论。在所提出的方案中，我们将 NOMA 系统中的联合 UP 和 PA 优化问题表述为一个宽松的稀疏 $l_{1}$ -norm 问题，基于这样一个事实，即有限的，即“稀疏”的用户数量必须通过专用资源块 (RB) 在大量用户之间进行配对。通过利用这种固有的稀疏性，我们可以通过放宽联合 UP 和 PA 的原始 NP-hard 问题来获得近乎最优的解决方案。然后，提出了一种 CS 技术来寻找松弛问题的解决方案。