This paper investigates Cell-Free massive MIMO networks, where each access point (AP) is equipped with a hybrid transceiver, reducing the complexity and cost compared to a fully digital transceiver. Asymptotic approximations for the spectral efficiency are derived for uplink and downlink. Capitalizing on these expressions, a max-min problem is formulated to optimize the (i) analog beamformer at the APs and (ii) pilot assignment. Simulations show that the optimization of these variables substantially increases the network performance.

翻译：本文件调查了无细胞大型MIMO网络,每个接入点都配备了一个混合收发机,与完全数字收发机相比,降低了复杂性和成本。光谱效率的Asymptical近似值是为上行和下行链接而得出的。利用这些表达方式,形成了一个最大问题,以优化(一) APs的模拟光束和(二) 试点任务。模拟表明这些变量的优化极大地提高了网络的性能。