Analysis of Area Spectral & Energy Efficiency in a CoMP-Enabled User-Centric Cloud RAN

Abstract

In this paper, we consider coordinated multipoint transmission (CoMP) by using distributed data base stations (DBSs) in a User-centric Cloud-based Radio Access Network (UCRAN). The creation of non-overlapping virtual cells (or service zones) centered around a user, contrary to traditional cellular architecture, shifts the mode of operation from base station centric “always ON” cells to user-centric “on-demand cells.” In contrast to existing literature, we show that CoMP is only beneficial in network architectures where cell-edge users are present. In a UCRAN architecture, where the cell-edge users are virtually removed due to non-overlapping user-centric cells, the performance gain provided by enabling CoMP is insignificant. We analyze this by performing a comparative performance analysis of UCRAN with different joint transmission schemes of CoMP. We also provide analytical expressions for network-wide coverage probability, area spectral efficiency, and energy efficiency by taking advantage of the stochastic geometry tools. Additionally, we investigate the impact of new degrees of freedom such as the size of the service zones and density of data base station on the spectral and energy efficiencies of CoMP-enabled UCRAN. Extensive Monte Carlo simulations validate the proposed analytical framework as well as provide useful insights into the design of next-generation cellular architectures.