Average Sum Rate of D2D Underlaid Multigroup Multicast Cell-Free Massive MIMO With Multi-Antenna Users

This letter proposes a device-to-device (D2D) underlaid multigroup multicast cell-free massive multi-input multi-output (MIMO) system with low-resolution digital-to-analog converters (DACs) at distributed access points (APs) and multiple antennas at both the APs and users. The closed-form rate expressions for cell-free users (CFUEs) and D2D users (DUEs) are derived using imperfect channel state information (CSI). Finally, simulation results for the achievable average sum rate shed light on the impact of key parameters and highlight the significance of the collaborative deployment of D2D and multigroup multicast cell-free massive MIMO.