A transmitter comprising a noise signal generator, a summing element configured to generate a signal as a sum of an output of the noise signal generator and a transmit data signal, and a transmit driver configured to generate an output signal based on the sum. Also, a method of calibrating a signal-to-noise ratio (SNR) for a transmitter comprising transmitting a first signal comprising a data signal with no noise signal, capturing the first signal, transmitting a second signal comprising a noise signal, wherein both an amplitude and a phase of the noise signal have been adjusted by a gain and phase control element, capturing the second signal, and determining the SNR corresponding to the captured first signal and the captured second signal, wherein the transmitter transmits the second signal using a transmit driver.