A return path transmitter includes an optical signal receiver configured to receive a digital optical signal and generate therefrom a first digitized RF data stream and a sample clock. The return path transmitter further includes an RF signal receiver, coupled to the optical signal receiver, configured to receive and convert the analog RF data signal into a second digitized RF data stream of digitized RF data samples at a rate determined by the sample clock. The return path transmitter further includes a summing circuit configured to mathematically sum the first and second digitized RF data streams so as to generate a third digitized RF data stream. The return path transmitter further includes an optical transmitter configured to convert an output data stream into a serialized optical data signal for transmission over an optical fiber, the output data stream including the third digitized RF data stream.