Design and performances of a low cost filtered COFDM system using π-constellations and real channel estimator

In order to de ne a multicarriers modem for High Frequency high rate radio communications we analyze new digital techniques. The system originality comes from the using of constellations with a low cost soft decision detector applied to fractionnally spaced multicarrier modulation [1]. We also demonstrate that even if the detector is more complex than a classical one it keeps the advantage to easily provide a soft bit information to a soft decoder.