Abstract
As wireless systems evolve toward higher frequencies and larger antenna arrays to meet the growing data rate demand, base stations (BSs) equipped with extremely large antenna arrays (ELAAs) increasingly serve users located in the near-field (NF) region. This paper investigates the performance of a network where an ELAA-assisted BS serves multiple users via NF beamfocusing in the polar domain. To characterize the complicated NF antenna pattern and inter-user interference, which jointly vary with angle and distance, we develop a novel stochastic geometry (SG)-based framework and propose a beam pattern approximation, i.e., NF multi-level antenna pattern (NF-MLAP). We then provide computationally efficient expressions for coverage probability (CP) and area spectrum efficiency (ASE). Numerical results validate the approximation accuracy and show how this framework can guide system design by balancing spatial resource reuse in the polar domain and inter-user interference.