Optimal Intersymbol Transmit Windowing for Multicarrier Modulation

Time-domain windowing of transmit blocks in multicarrier transmission is a technique frequently used to improve the properties of the transmit spectrum. An intersymbol window is longer than a multicarrier symbol including its cyclic extension. Before windowing, additional cyclic extensions at the beginning and at the end of each multicarrier symbol are introduced. Since the window only shapes these extended parts of each symbol, the orthogonality of the received basis functions is preserved. Most intersymbol transmit window designs exclusively focus on the spectral properties of the resulting basis functions. In this paper, we propose a window design that is optimal in the sense of maximising the information rate for a Gaussian channel with memory under power spectral density constraints and suggest some design guidelines