A wireless transmitter is disclosed that is capable of pre-compensating for oscillator phase noise. In the transmitter, an undesired phase noise being generated by a voltage-controlled oscillator can be detected by comparing the output of the voltage-controlled oscillator to a reference oscillator output. The phase can then be detected by calculating a desired number of zero crossings over a given time period, and comparing this value to an actual number of zero crossings detected in the signal generated by the voltage-controlled oscillator over the same period. From this, the phase component can be determined and digitally pre-compensated in a data signal.