Integrity monitoring system

An integrity monitoring system (IMS) monitors data upload errors, internal data processing errors, clock faults, and transmit signal distortions in a transmitter system. The IMS includes a receiver with an A/D converter that under-samples a multi-band RF signal to produce a composite, aliased IF digital signal. Individual signals are extracted from the composite signal via correlation with the appropriate spreading code. The resulting signals are evaluated to determine whether any signal distortion is present in the RF signals being transmitted, and data is extracted from the signals to perform checks of data uploaded to the transmitter system and data present in the transmitted RF signals that was generated within the transmitter system. The IMS also checks for clock faults in the transmitter system without requiring an independent timing reference by using clock phase information provided by the transmitter system's time keeping system.