Performance analysis of hexagonal cellular networks in fading channels

Abstract

This paper analyzes the location-dependent performance metrics of coverage probability and spectral efficiency in hexagonal cellular networks under Rayleigh fading with a general distribution for shadowing and also including two special cases of no shadowing and lognormal shadowing. The effects of system parameters such as frequency reuse factor, transmission probability of base stations, and signal-to-interference-plus-noise ratio gap from Shannon capacity are accurately characterized. The proposed approach is applied to fractional frequency reuse FFR scheme where the impact of FFR on spectral efficiency is evaluated. Numerical results show that i in a lognormal-shadowed Rayleigh fading channel with the shadowing standard deviation of 12dB, the cell area wide spectral efficiency is degraded by approximately 40% compared with when there is Rayleigh fading without shadowing; ii the improvement in spectral efficiency achieved by FFR over the universal frequency reuse increases as the transmission probability increases and the shadowing becomes less severe; and iii in Rayleigh fading without shadowing environment where all the base stations are actively transmitting, FFR achieves approximately 20% improvement in spectral efficiency in the cell edge area. Interestingly, this improvement increases to about 30% if a 3-dB signal-to-interference-plus-noise ratio gap from Shannon capacity is further accounted. Copyright © 2015 JohnWiley & Sons