A method (20) of orthogonal frequency-division multiplex (OFDM)
communication via a plurality of subchannels (30) within a noncontiguous
wideband channel (24) is provided. The method (20) determines an SNR for
each of the subchannels (30). The method (20) then designates a
subchannel (30) as clear (93) when its SNR is greater than a least-SNR
threshold (70), as impeded (95) when its SNR is less than the least-SNR
threshold and greater than an SNR-evaluation threshold, and as obstructed
(111) when its SNR is less than both the least-SNR and the SNR-evaluation
thresholds. The method (20) then transmits OFDM data (34) so that each of
the clear subchannels receives the OFDM data (34) at a maximum subchannel
signal level (40), each of the impeded subchannels receives the OFDM data
(34) at an intermediate subchannel signal level (42), and each of the
obstructed subchannels receives the OFDM data (34) at zero subchannel
signal level (44).