Performance Impact of LOS and NLOS Transmissions in Dense Cellular   Networks under Rician Fading
  In this paper, we analyse the performance of dense small cell network (SCNs). We derive analytical expressions for both their coverage probability and their area spectral efficiency (ASE) using a path loss model that considers both line-of-sight (LOS) and non-LOS (NLOS) components. Due to the close proximity of small cell base stations (BSs) and user equipments (UEs) in such dense SCNs, we also consider Rician fading as the multi-path fading channel model for both the LOS and NLOS fading transmissions. The Rayleigh fading used in most of existing works analysing dense SCNs is not accurate enough. Then, we compare the performance impact of LOS and NLOS transmissions in dense SCNs under Rician fading with that based on Rayleigh fading. The analysis and the simulation results show that in dense SCNs where LOS transmissions dominate the performance, the impact of Rician fading on the overall system performance is minor, and does not help to address the performance losses brought by the transition of many interfering signals from NLOS to LOS. 
Amir H. Jafari, Ming Ding, David Lopez-Perez, Jie Zhang
cs.IT math.IT