ENABLING THE 6G DIGITAL REVOLUTION THROUGH CELL-FREE NETWORKS: PERFORMANCE GAINS OVER CONVENTIONAL CELLULAR ARCHITECTURES

Abstract

The evolution toward sixth-generation (6G) wireless communication requires network architectures capable of supporting high data rates, low latency, reliable coverage and massive connectivity. However, the service quality of currently operated cellular networks is unreliable due to the significant variations within each cell. Hence, a cell-free network architecture which guarantees increased peak rates to the great majority of the areas throughout the geographical coverage area for future mobile networks is proposed. In this paper, a cell-free network is exploited to achieve higher and more uniform signal-to-interference-plus noise ratio (SINR) within the coverage area. Additionally, the cell-free network is combined with massive multiple-input multiple-output (mMIMO) technology envisioned for beyond fifth generation (B5G) cellular networks to further mitigate interference through joint processing at multiple access points (APs). Under a noise power of −86.98 dBm, simulation results show that cell-free mMIMO performs better than small cells networks by producing a gap of 4dB in the upper 95% probable SINR of the CDF curve. In addition, relative to the conventional cellular architecture, the proposed cell-free mMIMO system achieves a 32.24% improvement in average spectral efficiency, a 32.12% increase in average user throughput and a 233.22% improvement in 5th-percentile throughput, demonstrating substantial gains in both average and cell-edge user performance. The architecture also reduces average latency by 82.70%, while increasing coverage probability by 135.71%, from 17.50% to 41.25%. However, due to the implementation complexity of cell-free mMIMO, it is recommended that a robust user-centric AP selection and clustering algorithm be designed to reduce the backhaul.