UE Clustering Based on Grid Affinity Propagation for mmWave D2D in Virtual Small Cells

In this paper, Grid Assisted Affinity Propagation Clustering (GAPC) algorithm is proposed to enhance the total spectral efficiency of Cell Head based Virtual Small Cell (CHVSC) service by increasing the number of Cell Heads (CH). The algorithm builds upon the previous method of Modified Affinity Propagation Clustering (MAPC) with addition of grid zonal division and Depth-First Search algorithm for advanced eligible-UE selection. Afterwards, both SNR and SIR are used for member selection in GAPC-SNR and GAPC-SIR respectively. From Monte Carlo simulation, MAPC still have higher average SINR compared to GAPC-SNR, but GAPC algorithm outperforms the MAPC algorithm in the number of CH appointed. With the compensation of higher accuracy of cluster finding inside MBS service zone, GAPC-SNR enhances overall bandwidth efficiency, silhouette score, and reduces computational complexity, as well as alleviating traffic burdens for each CH in comparison to MAPC.