On time-variant distortions in multicarrier transmission with application to frequency offsets and phase noise

Phase noise and frequency offsets are, due to their time-variant behavior, one of the most limiting disturbances in practical orthogonal frequency-division multiplexing (OFDM) designs, and therefore, intensively studied by many authors. In this paper, we present a generalized framework for the prediction of uncoded system performance in the presence of time-variant distortions, including the transmitter and receiver pulse shapes, as well as the channel. Therefore, unlike existing studies, our approach can be employed for more general multicarrier schemes. To show the usefulness of our approach, we apply the results to OFDM in the context of frequency offset and Wiener phase noise, yielding improved bounds on the uncoded performance. In particular, we obtain exact formulas for the averaged performance in additive white Gaussian noise and time-invariant multipath channels.