Critical carrier frequency offset for uplink OFDMA carrier allocation schemes without channel state information

Orthogonal Frequency Division Multiple Access (OFDMA) is very sensitive to the carrier frequency offsets (CFO) which results in intercarrier interference (ICI). In OFDMA carrier allocation is used to improve system performance. In this paper we analyze the effect of carrier allocation schemes on the CFO induced interference in an uplink OFDMA system without channel state information (CSI). We also propose a critical value of CFO for block carrier allocation scheme above which the system´s performance shows significant degradation.