Scalable Simultaneous Connectivity with Multiple APs and Virtual UEs in CF-Networks

초록

Cellular massive multiple-input multiple-output (mMIMO) enables several access points (APs) to cooperatively serve multiple user equipment (UEs) using dynamic cooperative clustering (DCC) in a single cell. As the UE moves away from the cell center, it creates intercell signal interference (ISI) on cell edges which degrades the network performance. To overcome this issue, the cell-free (CF) networks remove the cell boundaries and randomly distribute the APs equipped with a variable number of antennas. CF aims to enable several APs to jointly serve the UEs in the network to improve the data rate. The scalable CF networks have been proposed for practical implementation, but it enables a single master AP (MAP) to communicate with UEs. It creates signal overhead on fronthaul in large networks and degrades spectral Efficiency (SE). To overcome this issue, we proposed a scalable scheme to enable simultaneous connectivity between multiple APs and UEs using virtualization. Each UE create virtual network interface card (vNIC) ids and integrate them with UE physical id to separately identify each signal in the network. The novel UE ids can independently identify each id as a separate UE in the network. A novel channel gain-based AP selection methodology on UE has been proposed. Moreover, space division multiple access (SDMA) has been utilized for simultaneous uplink/downlink connections. The goal of the work is to enable UEs to maintain multiple AP connections without increasing their physical capacity. The proposed scheme simulation results are compared with other proposed schemes and it shows promising improvement in the network.

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