Spectrum and energy efficiency analysis of ultra dense network with sleep

Abstract

Recently, Ultra Dense Network (UDN) emerges as one of the state-of-the-art technologies to cope with the pressure of the ever-growing traffic demands in wireless communication. By deploying dense Base Stations (BSs) to provide ubiquitous coverage and high-speed transmission, it is considered as one of the most promising paradigms. However, large numbers of BSs bring the rise of the energy consumption of circuit and other costs for maintenance. Therefore, along with spectrum efficiency, the energy efficiency also becomes a major concern in UDN. In this paper, we analyze the UDN performance on both network Spectrum Efficiency (SE) and network Energy Efficiency (EE) with sleep mode. We first offer an alternative analytical expression of the average achievable rate. Then we modified the existing stochastic model where BSs and users are modeled as the Poisson Point process (PPP). Unlike the previous work, we introduce the active BSs density and show its relationship with densities of BSs and users. After that, we analytically derive the expression of the network SE and EE, and analyze the network performance through numerical simulations. We further do practical simulations to prove the validity of our analysis. In the end, we draw the conclusions that tradeoff needs to be made since different network performance metrics cannot be optimal at the same time.