A system for identifying at least one phase transition in a phase-shift keying signal comprising a plurality of data samples corresponding to phase values. The system comprises a memory operable to store computing device executable instructions; and a computing device. The computing device is operable to generate a first falling edge region function for each data sample; generate a first rising edge function for each data sample; generate a first level function for each data sample; and generate a second falling edge function for each data sample. The second falling edge function equals the first falling edge function if the first falling edge function is greater than the first rising edge function and the first level function, and the second falling edge function equals zero.