Energy Efficiency Analysis of Heterogeneous Cellular Networks With Extra Cell Range Expansion

TL;DR

This paper introduces a flexible extra cell range expansion framework for heterogeneous cellular networks, analyzing its impact on energy efficiency through stochastic geometry and providing practical design insights.

Contribution

It proposes a novel extra cell range expansion method with an additional bias factor, enabling better energy efficiency analysis in two-tier HCNs.

Findings

Extra CRE improves energy efficiency in HCNs.

Deploying more small cells enhances EE coverage up to a threshold.

Theoretical analysis aligns with numerical simulations.

Abstract

The split control and user plane is key to the future heterogeneous cellular network (HCN), where the small cells are dedicated for the most data transmission while the macrocells are mainly responsible for the control signaling. Adapting to this technology, we propose a general and tractable framework of extra cell range expansion (CRE) by introducing an additional bias factor to enlarge the range of small cells flexibly for the extra offloaded macrousers in a two-tier HCN, where the macrocell and small cell users have different required data rates. Using stochastic geometry, we analyze the energy efficiency (EE) of the extra CRE with joint low power transmission and resource partitioning, where the coverages of EE and data rate are formulated theoretically. Numerical simulations verify that the proposed extra CRE can improve the EE performance of HCN, and also show that deploying more small cells can provide benefits for EE coverage, but the EE improvement becomes saturated if the small cell density exceeds a threshold. Instead of establishing the detail configuration, this paper can provide some valuable insights and guidelines to the practical design of future networks, especially for the traffic offloading in HCN.