I. Introduction
BROADBAND wireless access to the Internet has been the focus of research and development efforts of many research groups and organizations for the past few years, e.g., [2]–[6]. For example, reference [2] proposes a high speed asymmetrical wireless system based on EDGE uplink and OFDM downlink with the requirements envisioned for 3G systems in mind. Reference [3] focuses on the physical and MAC layer of the 2.4 GHz and 5.2 GHz band IEEE 802.11 standard as well as on the Magic WAND project as a precursor of the HiperLAN-2 standard. A description of the structure of the data packet, of the underlying OFDM symbol, and of the training and pilot signals is given for the OFDM based 5.2 GHz band 802.11 standard and the Magic WAND project. OFDM has been adopted, or is being proposed, as the preferred transmission technique for several recent standards for wireless LANs and for fixed wireless access systems, especially in the unlicensed bands.