Driven by the ultra-high throughput requirements of 6G, wireless communications are migrating to centimeter wave (cmWave) bands to overcome the limitations of current spectral resources. Massive multiple-input multiple-output (MIMO) and orthogonal frequency division multiplexing (OFDM) systems aim to achieve high spectral efficiency in cmWave regimes but are often constrained by the heavy overhead of downlink channel state information (CSI) feedback. This paper proposes a deep learning scheme based on the multi-axis multi-layer perceptron for image processing (MAXIM) architecture for joint semantic CSI feedback and hybrid beamforming in multi-user cmWave MIMO-OFDM systems, which maximizes the downlink sum rate by end-to-end optimization. Specifically, distributed encoders at multiple user equipments (UEs) perform limited CSI feedback, while the decoder at the base station (BS) jointly designs the hybrid beamforming matrices without explicit CSI reconstruction. The uplink transmission is implemented via deep joint source-channel coding (DJSCC) to enhance CSI compression efficiency and noise robustness. Furthermore, considering the high correlation between vertical and horizontal polarization channels in dual-polarized massive MIMO systems, a cross-polarization interaction module is introduced at the UEs to exploit polarization correlations for joint CSI compression. Simulation results demonstrate that the proposed method improves the downlink sum rate under various signal-to-noise ratio (SNR) conditions with a limited number of feedback symbols, validating its robustness and superiority in multi-user dual-polarized cmWave MIMO-OFDM systems.

翻译：受6G超高吞吐量需求的驱动，无线通信正向厘米波频段迁移以突破当前频谱资源限制。大规模多输入多输出与正交频分复用系统旨在厘米波场景实现高频谱效率，但常受限于下行信道状态信息反馈的高开销。本文提出一种基于MAXIM架构的多轴多层感知机深度学习方案，用于多用户厘米波MIMO-OFDM系统的联合语义CSI反馈与混合波束成形，通过端到端优化最大化下行和速率。具体地，多个用户设备的分布式编码器执行有限CSI反馈，而基站侧解码器在不显式重构CSI的情况下联合设计混合波束成形矩阵。上行链路传输通过深度联合信源信道编码实现，以增强CSI压缩效率与噪声鲁棒性。此外，针对双极化大规模MIMO系统中垂直与水平极化信道高度相关特性，在用户设备端引入交叉极化交互模块，利用极化相关性实现联合CSI压缩。仿真结果表明，所提方法在有限反馈符号数下，能提升多种信噪比条件下的下行和速率，验证了其在多用户双极化厘米波MIMO-OFDM系统中的鲁棒性与优越性。