An analog front end for communicating discrete multitone modulated signals
on a subscriber line includes a transmit block, a receive block, and a
hybrid packaged within a same integrated circuit. Upstream data to be
transmitted to the subscriber line is pre-processed to eliminate even
images. A power spectral density shaping filter subsequently
substantially eliminates undesired energy in the upstream data signal. A
high pass filter further rejects upstream data from the downstream data
signal. The power spectral density filter and the high pass filter enable
the use of a first order hybrid network for extracting the downstream
data. The analog front end may include an additional analog channel to
enable voiceband (e.g., v.90) communication concurrent with non-voiceband
(e.g., xDSL) operation. Sample rate conversion is utilized to avoid the
use of multiple independent clocks for otherwise incompatible clocking
requirements.