Evaluating OFDM Performance under Carrier Frequency Offset Effects

The purpose of this study is to evaluate how Orthogonal Frequency Division Multiplexing (OFDM) systems function when their carrier frequency offset is fixed or random. The effect of carrier frequency offset on subcarrier orthogonality and the ensuing inter-carrier interference (ICI) are investigated through simulation using MATLAB. The results show that, even in the presence of a high signal-to-noise ratio (SNR), a small frequency offset can cause a significant decline in bit error rate (BER). The BER vs SNR plot demonstrates that even a slight increase in the carrier frequency offset, such as 0.25, negatively affects the BER vs SNR curve. Moreover, for a frequency offset of 0.5, the BER vs SNR curve becomes a flat line, indicating no improvement in SNR. These findings emphasize the critical role of managing carrier frequency offset in OFDM systems to maintain performance and mitigate interference.