The effect of unknown non-flat interference power spectral density in OFDMA cellular system

In an OFDMA network, the downlink power spectral density (PSD) is varying dynamically to support multiple access, it is quite difficult to obtain the instantaneous interference PSD through either measurements or signaling. In this paper, we evaluate the impact of unknown non-flat interference in OFDMA system. We compare the performance of three different receiver algorithms under the effect of unknown non-flat interference PSD for AWGN and fading channel. We prove that there is a significant performance lose if we don´t know the exactly interference PSD in some case. We will demonstrate the effect of interference under several factors, including SIR, the loading factor and D_min of receiver codeword.