1. US5022048 - Programmable digital frequency-phase discriminator

A present invention novel frequency-phase discriminator has input channels for real and imaginary data which are coupled to two programmable despreaders. The first despreader has its real and imaginary outputs coupled to individual programmable data rate filters which have their individual outputs coupled to a quadrant detector that generates a phase angle direction signal and sign magnitude. The second despread has its real and imaginary outputs connected through individual programmable inverters to data rate filters which have their individual outputs coupled to a quadrant selector that selects error signal data rate information from one of four quadrant axes signals. A command generator is programmably coupled to the output of the quadrant detector and to the input of the quadrant selector and provides a selection signal to the quadrant selector which produces a frequency error signal output employed in a frequency lock loop or in a phase lock loop.