This paper studies the exploitation of triple polarization (TP) for multi-user (MU) holographic multiple-input multiple-output surface (HMIMOS) wireless communication systems, aiming at capacity boosting without enlarging the antenna array size. We specifically consider that both the transmitter and receiver are equipped with an HMIMOS comprising compact sub-wavelength TP patch antennas. To characterize TP MUHMIMOS systems, a TP near-field channel model is proposed using the dyadic Green's function, whose characteristics are leveraged to design a user-cluster-based precoding scheme for mitigating the cross-polarization and inter-user interference contributions. A theoretical correlation analysis for HMIMOS with infinitely small patch antennas is also presented. According to the proposed scheme, the users are assigned to one of the three polarizations, which is easy to implement, at the cost, however, of reducing the system's diversity. Our numerical results showcase that the cross-polarization channel components have a nonnegligible impact on the system performance, which is efficiently eliminated with the proposed MU precoding scheme.

翻译：本文研究了三极化（TP）在多用户（MU）全息多输入多输出表面（HMIMOS）无线通信系统中的应用，旨在不扩大天线阵列尺寸的情况下提升系统容量。具体考虑发射端和接收端均配备由紧凑型亚波长TP贴片天线构成的HMIMOS。为刻画TP-MU-HMIMOS系统，利用并矢格林函数提出了TP近场信道模型，并基于该模型特性设计了一种基于用户簇的预编码方案，以抑制交叉极化干扰和多用户干扰。同时给出了无限小贴片天线HMIMOS的理论相关性分析。根据所提方案，用户被分配到三种极化之一，该方法易于实现，但代价是降低了系统分集增益。数值结果表明，交叉极化信道分量对系统性能具有不可忽略的影响，而所提多用户预编码方案可有效消除该影响。