Radio remote interface for modulating/demodulating data in a digital communication system

There is disclosed in a digital communications system for communicating between two radios by transceiving a signal comprising a first type control signal, a second type data traffic signal and a third type voice signal, a remote communication interface for providing transmission therebetween comprising a duplexer/bridge network for transceiving the signal, means for determining the signal type to be transmitted, low pass filters and analog to digital and digital to analog converters for processing received and transmitted signals, and a digital signal processor for modulating and demodulating the signal for transmission/reception according to the signal type. There is also disclosed means for adjusting the clock sampling frequency during the demodulation process to obtain bit sync, bit tracking and frequency tracking. The communication interface is operable to transceive either the modulated traffic, control, or voice signal, or combined modulated traffic and control signal, or combined modulated voice and control signal.