Stereo decoding by direct time sampling

Abstract

A stereo decoder is provided for decoding an encoded stereo signal. In one form, the encoded stereo signal is digitized and coupled to two sampling circuits. By selectively sampling the encoded signal relative to a stereo pilot signal contained in the encoded signal, both a left-hand audio signal and a right-hand audio signal may be separately recovered from the encoded signal and latched. A phase locked loop monitors the phase of the stereo pilot signal relative to the encoded signal and controls the time sampling of the encoded signal at predetermined phases of the pilot signal. The stereo decoding may also be performed by using analog circuitry to directly time sample the encoded stereo signal. In an analog approach, the time sampled output signal must be low pass filtered to provide decoded stereo output signals.