I. Introduction
Orthogonal frequency division multiplexing (OFDM) is a widely adopted modulation technique for high-speed wireless communications. The OFDM-based physical layer has been chosen for several standards, such as the IEEE 802.11a wireless local area network (WLAN) in the 5-GHz band, the IEEE 802.11g wireless local area network (WLAN) in the 2.4 GHz band, and the European digital video broadcasting system (DVB-T). It is also under consideration as the high rate alternate physical layer to the draft IEEE P802.15.3 wireless personal area network (WPAN), the IEEE 802.20 mobile broadband wireless access (MBWA), and the IEEE 802.16 wireless metropolitan area networks (WirelessMAN). Considering the large demand for such systems, a low-cost, low-power, and fully integrated implementation of these standards is a challenge for the future high-speed wireless networks.