Characteristics of inter-cell interference for OFDMA systems in multipath Relaying fading channels

In this paper, we investigate the characteristics for inter-cell interference of OFDMA cellular systems in multipath Rayleigh fading channels. Our approach is based on the special structure of OFDM channel matrix resulting from the cyclic prefix, which converts a linear convolution channel into a circular convolution channel. The characteristics of inter-cell interference is contingent upon, such as the asynchronous timing offset between co-channel cells, signal modulation schemes used, the system loading, and allocated subcarrier patterns. We further identify the probability distribution of inter-cell interference according to different combination of these variable elements. Analytical results indicate that the inter-cell interference exactly has a Gaussian distribution, provided that it is modulated by phase-shift keying (PSK). Otherwise, the inter-cell interference is multivariate Gaussian-mixture distributed. In addition, the correlation be-tween subcarriers can be ignored safely without imposing two much discrepancy in performance evaluation.