Joint spectrum-sharing and base-station-sleep model for improving energy efficiency of HetNet

A joint optimization method considering both Partial-Spectrum-Reuse (PSR) scheme and base-station-sleep (BSS) is proposed for improving the energy efficiency in heterogeneous networks (HetNets). We derive the coverage probabilities for both the macro-tier and micro-tier networks, followed by maximizing the HetNet´s coverage probability through optimizing both the PSR factor and macro-micro base station´s active probability ratio (APR). Furthermore, the problem of energy-consumption-minimization in the whole HetNet can be addressed by analyzing the relationship between the optimal PSR factor and APR. Numerical results show that the proposed joint optimization method is capable of saving network energy consumption of up to 50% when the signal-to-interference-and-noise ratio (SINR) target is set to be 20 dB.