Coverage Analysis of Inter-Tier Interference Cancellation for Massive MIMO HetNet With Repulsion

The inter-tier interference cancellation (IC) by employing zero-forcing precoding method for two-tier heterogeneous network under considering repulsion between base stations (BSs) with adopting the β-Ginibre point process (β-GPP) model is investigated here. The distribution of the number of users that request IC under β-GPP model is first derived. Then, the approximation for coverage probability of the typical user with inter-tier IC is given out under massive multiple-input multiple-output (MIMO) assumption. Numerical results validate the accuracy of the approximation, and show that, compared with Poisson point process model, the β-GPP model is more accurate in prediction of the coverage probability in actual network with inter-tier IC. Furthermore, when the number of antennas in macro BS and that of users all approach infinity with fixed ratio, the coverage probability when the user is served by the macro BS can be simplified to a simple closed-form formula, which reveals the potential of massive MIMO to improve user performance under the case of large signal-to-interference ratio threshold.