Title: Impact of Phase Noise and Power Amplifier Non-Linearities on Downlink Cell-Free Massive MIMO-OFDM Systems Show Chinese title

Title: 相位噪声和功率放大器非线性对下行链路无蜂窝大规模MIMO-OFDM系统的影响

Abstract: Cell-free massive MIMO (multiple-input multiple-output) is a key enabler for the sixth generation (6G) of mobile networks, offering significant spectral and energy efficiency gains through user-centric operation of distributed access points (APs). However, its reliance on low-cost APs introduces inevitable hardware impairments, whose combined impact on wideband downlink systems remains unexplored when analyzed using behavioral models. This paper presents a comprehensive analysis of the downlink spectral efficiency (SE) in cell-free massive MIMO-OFDM systems under practical hardware impairments, including phase noise and third-order power amplifier nonlinearities. Both centralized and distributed precoding strategies are examined. By leveraging the Bussgang decomposition, we derive an SE expression and quantify the relative impact of impairments through simulations. Our results reveal that phase noise causes more severe degradation than power amplifier distortions, especially in distributed operation, highlighting the need for future distortion-aware precoding designs. Show Chinese abstract

Abstract: 无蜂窝大规模MIMO（多输入多输出）是第六代（6G）移动网络的关键使能技术，通过分布式接入点（AP）的用户中心操作提供显著的频谱和能量效率增益。 然而，其依赖低成本AP会引入不可避免的硬件损伤，在使用行为模型分析时，这些损伤对宽带下行系统的影响尚未被研究。 本文对在实际硬件损伤下无蜂窝大规模MIMO-OFDM系统的下行频谱效率（SE）进行了全面分析，包括相位噪声和三阶功率放大器非线性。 研究了集中式和分布式预编码策略。 通过利用Bussgang分解，我们推导出SE表达式，并通过仿真量化了损伤的相对影响。 我们的结果表明，相位噪声造成的退化比功率放大器失真更严重，尤其是在分布式操作中，这突显了未来考虑失真的预编码设计的必要性。