I. Introduction
Recently, multicarrier modulation has been considered to be a candidate to support wideband wireless communication with guaranteed quality of service (QoS). Instead of employing a very complicated adaptive equalizer to combat the intersymbol interference (ISI) [1]–[3], multicarrier modulation [4]–[6] satisfies such a stringent service requirement by dividing the single wideband channel into many subchannels that are free of ISI.