a method and system for compensating digital data demodulation phase uncertainty is provided . the method includes the steps of identifying a phase reference quadrant , the phase reference quadrant having a phase reference axis and four quadrants , i , ii , iii , and iv ; receiving known digital data ; and forming a phase vector from the known digital data , determining which quadrant the phase vector is located in and rotating the phase vector to the phase reference quadrant if it is determined that the phase vector is not located in the phase reference quadrant . the last step generates a phase error signal proportional to the resulting angle by rotating the phase vector − 45 ° and measuring the resulting angle between the phase vector and the phase reference axis .