Energy-Efficient Small Cell Cooperation in Ultra-Dense Heterogeneous Networks

This letter introduces a user-centric small cell clustering mechanism, which: 1) strengthens the received signal-to-interference-ratio (SIR) by small cell cooperation and 2) enables interference cancellation significantly through a user served by multiple cells in its vicinity. Consequently, we model this protocol with a Matern cluster process (MCP) and present a new mathematical framework to study the average downlink rate of it. Then, a new formula for area spectral efficiency (ASE) with respect to cooperation number of the clustering mechanism is derived. Finally, the impact of cooperation number on energy efficiency (EE) is investigated. Simulation results demonstrate the optimal cooperation number which maximizes EE and validate the accuracy of theoretical analysis.