A system and method including deriving a subcarrier frequency from a binary data stream having a clock frequency, wherein the subcarrier frequency is substantially the same as the clock frequency; gating the subcarrier frequency using the data stream to produce a modulated OOK signal; determining a OOK subcarrier center frequency based on the modulated OOK signal with the clock frequency; delaying the modulated OOK signal relative to the binary data stream by a predetermined amount to produce a delayed modulated OOK signal; conditioning the modulated OOK signal and the delayed modulated OOK signal to create a differential transition signal in an I channel and a Q channel to provide a stable amplitude signal level reference at an input to an I and Q vector modulator.