Large System Analysis of Heterogeneous Cellular Networks With Interference Alignment

In this paper, we conduct large system analysis of heterogeneous cellular networks (HCNs) which are modeled as a two-tier cellular network consisting of one macro base station (MaBS) and multiple micro base stations (MiBSs) distributed according to a Poisson point process. Interference alignment is performed via rank constrained rank minimization (RCRM) to design the transmit precoding and receive beamforming matrices of the users in HCNs for the suppression of interference signal. We then analyse the average achievable rate for both macro users (MaUEs) and micro users (MiUEs) with an objective of obtaining a closed-form expression. It is shown that the MaUE and MiUE rate expressions are functions of the transmit power, noise power, MiBS density, and the transmit distance. Extensive simulations show that the rate expressions derived through large system analysis provide accurate estimates of the average achievable rates of HCNs with different system parameters.