Improving an OFDM reception using an adaptive Nyquist windowing

This paper explains how a windowing of the OFDM-signal in the time domain contributes to its improved reception. The windowing uses the part of the guard interval that is not disturbed by multipath reception. The length of the window adapts to the transmission conditions. This window may be realized with a raised cosine or other kind of function that fulfils the Nyquist criterion. An easy way to implement the windowing while keeping the FFT complexity low is also shown. The impact of windowing for discrete sine spurious, white noise, phase noise and frequency deviations is also given. OFDM is of interest in terrestrial broadcasting.