Analysis of cell spectral efficiency of infrastructure relay-enhanced cellular system

In this paper, we investigate the downlink spectral efficiency of infrastructure relay-enhanced cellular systems. In particular, we use the average achieved spectral efficiency at an arbitrary mobile receiver in presence of co-channel interference, termed as cell spectral efficiency (CSE), to quantify the benefit of relay transmission in terms of lower co-channel interference power. We derive the exact analytical expression of CSE for relay-enhanced system with different transmission strategies while taking into account the random user locations and the impact of pass loss. We show through selected numerical examples that the relay-enhanced systems have the potential to achieve much better CSE performance over the conventional systems.