A communication system includes a digital data processor that produces a digital data sample and one or more control bits. A serialized transmit interface combines the digital data sample and the control bit(s) into one or more data packets and sends the data packet(s) over a signal line. A serialized receive interface receives the transmitted data packet(s) from the signal line and produces a reconstructed digital data sample and the control bit(s) from the transmitted data packet(s). A control circuit coupled to the serialized receive interface produces a control signal from the control bit(s). The communication system may include a converter circuit, which produces an RF input signal by performing a digital-to-analog conversion of the reconstructed digital data sample, and by upconverting the resulting analog data sample signal to RF. A power amplifier amplifies the RF input signal and modifies operation of a sub-circuit based on the control signal.