SUBMITTED TO IEEE TRANSACTIONS ON SIGNAL PROCESSING, APRIL 2004 1 A Pseudo Random Postﬁx OFDM modulator Part I: Semi-blind channel estimation and equalization in the static case Markus Muck, Member, IEEE, Marc B. De Courville, Member, IEEE, Pierre Duhamel, Fellow, IEEE Abstract This two part paper 1 details a new OFDM modulator based on the use of a Pseudo Random Postﬁx (PRP-OFDM) and discusses low complexity equalization and channel estimation/tracking architectures. The main property of this new modulation scheme is the ability to estimate and track the channel variations semi-blindly using order one statistics of the received signal. This scheme is thus suited to situations where large Doppler spreads exist, and where channel tracking becomes essential. Various equalization structures derived from zero padded transmission schemes are proposed, allowing implementations spanning the whole range from low-complexity/medium performance to increased-complexity/high performance. Part I (this paper) covers the basic principles in a static environment, while part II focuses on the time-varying case. I. I NTRODUCTION O RTHOGONAL Frequency Division Multiplexing (OFDM) nowadays seems the preferred modulation scheme for modern broadband communication systems. Indeed, the OFDM inherent robustness to multi- path propagation and its appealing low complexity equalization receiver make it suitable either for high speed modems over twisted pair (digital subscriber lines xDSL), terrestrial digital broadcasting (Digital Audio and Video M. Muck and M. de Courville are with Motorola Labs, Parc Les Algorithmes, 91193 Gif-Sur-Yvette, France, EMail: {Markus.Muck, Marc.De.Courville}@motorola.com, P. Duhamel is with CNRS/LSS, Supelec, Plateau de moulon, 91192 Gif-sur-Yvette, France, EMail: pierre.duhamel@lss.supelec.fr. 1 This work is supported by the European Commission in the scope of the IST BROADWAY PROJECT IST-2001-32686 [1].