Analysis and Performance of Beam Management in 5G Networks.

Carrier frequencies above 6 GHz are adopted for the upcoming fifth generation (5G) mobile networks since they offer higher data rates than today’s legacy networks. High frequencies allow the deployment of multiple antenna elements in single antenna array. Analog, digital, and hybrid beamforming techniques are practiced to generate beams with high beamforming gain compensating for the increased path loss. In 5G, the user equipments (UEs) are not only connected to cells, but also served by specific beams of the cells. This study investigates the beam management procedures specified in the 3rd Generation Partnership Project (3GPP) standard that control the intra-cell UE mobility, which is the mobility of the UEs between beams of single cell. This work defines a comprehensive system model to evaluate the concepts of intra-cell mobility in a representative scenario and network deployment. Moreover, this paper focuses on the implementation of the beam switching algorithm, which is a key element of the beam management procedures. Herein, an additional layer of filtering is introduced at the network side to reduce the fluctuations in the UE measurements that are caused by fast fading and measurement errors. Using the filtered measurements, several methods for beam switching are designed and evaluated. The results reveal that the proposed methods provide means to enhance the robustness of intra-cell UE mobility by decreasing the outage percentage, as well as the signaling overhead associated with the beam management procedures.