System for recovery of digital data from amplitude and phase modulated line signals using delay lines

A method of recovery digital data from a received amplitude and phase modulated line signal, comprising the steps of:

• decoding said line signal to determine an amplitude value corresponding to an amplitude of said line signal,
• calibrating a reference delay line using a reference signal at a frequency of said line signal,
• adjusting a receive delay line in accordance with said reference delay line,
• supplying said receive delay line with said line signal to produce reference phase values delayed with respect to each other,
• comparing said line signal with said reference phase values to determine a phase value corresponding to a phase of said line signal, and
• decoding said amplitude value and said phase value to identify digital data represented by the amplitude and phase of said line signal.

A system for demodulating an amplitude and phase modulated signal, comprising:

• an amplitude decoder for detecting an amplitude value of the modulated signal,
• an adjust delay line for producing a plurality of reference phase values delayed with respect to each other,
• a phase matching circuit for comparing the modulated signal with the plurality of reference phase values to determine a phase value of the modulated signal, and
• a symbol detector responsive to the amplitude value and the phase value of the modulated signal for identifying data represented by the modulated signal.