In this work, a resource allocation problem is investigated for a relay-based multiuser cooperative orthogonal frequency division multiple access (OFDMA) uplink system, considering a very large antenna array at the base station and nonlinear power amplifiers (PAs) in both user and relay nodes. Firstly, a theoretical characterization of the considered scenario is performed. Then, some analytical expressions for the nonlinear distortion (NLD) variance and the PA constant of a third-order polynomial PA are derived, as well as the instantaneous signal-to-noise ratio (SNR) of the considered system is calculated. Then, a low-complexity suboptimal relay selection and subcarrier allocation technique is proposed for the considered scenario based on the developed expressions. Numerical simulation results are presented to validate the derived expressions and to evaluate the performance of the proposed technique.

中文翻译：

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具有非线性功率放大器的多用户协作 OFDMA 上行链路：理论特性和资源分配

在这项工作中，研究了基于中继的多用户协作正交频分多址 (OFDMA) 上行链路系统的资源分配问题，考虑到基站的超大天线阵列和用户和中继中的非线性功率放大器 (PA)节点。首先，对所考虑的场景进行理论表征。然后，推导了非线性失真（NLD）方差和三阶多项式PA的PA常数的一些解析表达式，并计算了所考虑系统的瞬时信噪比（SNR）。然后，基于所开发的表达式，针对所考虑的场景提出了低复杂度次优中继选择和子载波分配技术。