On Capacity and Association Area Characterization in Small Cell-Based Multi-Tier Networks

A mathematical framework is developed for statistical characterization of association cell and channel capacity in co-channel two-tier networks. The cell association and capacity derivation are based on maximum instantaneous received power (IRP) or equivalently Max-SIR in the downlink. We consider two-tier networks consisting of Macro cell base station (MBS) and small cell base station (SCBS). Characterizing coverage in multi-tier networks is critical as it is connected directly to network throughput and load. Two channel models, Log-normal shadowing and Nakagmi- m fading are considered to account for multipath fading. It is shown that in both channel models the cell association areas of SCBS have different behavior compared to path-loss only case. Numerical results provided herein confirm the validity of analytical results.