Clustered Cell-Free Networking: A Graph Partitioning Approach

By moving to millimeter wave (mmWave) frequencies, base stations (BSs) will be densely deployed provide seamless coverage in sixth generation (6G) mobile communication systems, which, unfortunately, leads severe cell-edge problem. In addition, with massive multiple-input-multiple-output (MIMO) antenna arrays employed at BSs, the beamspace channel is sparse for each user, and thus there no need serve all users a cell by beams therein jointly. Therefore, it of paramount importance develop flexible clustered cell-free networking scheme that can decompose whole network into number weakly interfered small subnetworks operating independently parallel. Given per-user rate constraint service quality guarantee, this paper aims maximize decomposed so as reduce signaling overhead system complexity much possible. formulating bipartite graph partitioning problem, rate-constrained decomposition (RC-NetDecomp) algorithm proposed, which smoothly tune structure from current cellular simple beam allocation fully cooperative increasing required rate. Simulation results demonstrate proposed RC-NetDecomp outperforms existing baselines terms average rate, fairness among energy efficiency.