The wireless communication device and corresponding method described herein selectively switches between a single-frequency mode, such as appropriate for an EDGE network, and a multiple-frequency mode, such as appropriate for a multi-carrier EDGE network. Accordingly, a transmitting wireless communication device selectively switches between a single-channel mapping unit, used during the single-frequency mode, and a multi-channel mapping unit, used during the multiple-frequency mode. The multi-channel mapping unit modulates input data to output a modulated data stream for each of multiple adjacent frequency channels that, when combined, produce a multiple-frequency signal with reduced peak-to-average ratio. A receiving wireless communication device selectively switches between a single-channel demodulator, used during the single-frequency mode, and a multi-channel demodulator, used during the multiple-frequency mode.