HARQ in Poisson Point Process-based Heterogeneous Networks

Paper in proceeding, 2015

Hybrid automatic repeat request (HARQ) plays an important role in improving the transmission efficiency and the robustness of wireless networks. Considering K-tier heterogeneous networks (HetNets) and modelling the locations of the base stations (BSs) as a homogeneous Poisson point process (PPP), this paper investigates the performance of HetNets implementing HARQ. We give closed-form expressions for the coverage probability and the per-user throughput with HARQ and show that using HARQ can indeed improve the coverage probability. However, depending on the channel conditions, the per-user throughput of the HetNets may decrease by the implementation of HARQ. Furthermore, we show that the small cell density has negligible effect on the coverage probability and per-user throughput, and the per-user throughput may increase with the small cell path loss.