Characteristics and modelling of inter-cell interference for orthogonal frequency-division multiple access systems in multipath Rayleigh fading channels

In a multi-cellular system, inter-cell interference is one of the major impairments that limit system performance. Accurate knowledge of inter-cell interference is a key step towards determination of link performance and system capacity efficiently. For orthogonal frequency-division multiple access (OFDMA) systems, the inter-cell interference has been studied in the literature mainly through computer simulation, which is very time-consuming, particularly in a heavily loaded operation. Through an analytical approach, this study investigates the characteristics and modelling of inter-cell interference for OFDMA systems in multipath Rayleigh fading channels. Analytical results indicate that the inter-cell interference exactly has a Gaussian distribution, provided that it is modulated by phase-shift keying. Otherwise, the inter-cell interference is multivariate Gaussian-mixture distributed. In addition, the cross-correlation of interference among subcarriers is insignificant, according to the analytical result. Simulation results also indicate that the cross-correlation can be safely ignored while modelling the inter-cell interference. In summary, the authors accurately characterise the inter-cell interference and analytical results provide an efficient way to generate inter-cell interference for OFDMA multi-cellular systems, which is very time-consuming through real computer simulations.