Transmission quality impairments in an OFDM system

The OFDM technique and basic transceiver configuration are presented. In OFDM technique many identical components as in single-carrier modulation formats are used, but the essential part is the FFT and IFFT processor. Because the Fourier transform is a fundamental operation in OFDM, the effects of several impairments can be intuitively understood by applying Fourier transform theory. Frequency errors, noise effects and nonlinear circuits contribute mostly to the impairments which results in inter-carrier interference (ICI), inter-symbol interference (ISI) and inter-bin interference (IBI). These impairments introduces errors into the constellation diagrams of the subcarriers and thus increase the bit error rate (BER).