BER sensitivity of OFDM systems to carrier frequency offset and Wiener phase noise

An OFDM signal consists of N sinusoids (bins) with spacing 1/T, that are modulated by data symbols that have a duration T, equal to the inverse channel spacing. Hence, although the modulated bins spectrally overlap, they are orthogonal. The generation of the OEDM signals at the transmitter and the demodulation at the receiver can be pedormed efficiently by means of Fast Fourier Transforms. The use of OEDM signals has been proposed for various applications, such as broadcasting of digital audio and digital TV, and high bit rate transmission on twisted pair cables [ 1-41. During a symbol period T, the complex envelope of the transmitted OFDM signal can be expressed as