The basis of this research is directed towards the Private Mobile Radio (PMR) networks, which play significant roles in taxi, police, ambulance and other such services. With an ever increasing need for data transmission, the current PMR systems which were designed for voice are not adequate. This research will examine a digital modulation scheme which can co-exist with an analog system. The generation of the digital modulation will be examined in terms of Adjacent
Channel Interference (ACI) requirements. Simulation techniques for the mobile radio channel are discussed, for evaluation of demodulator performance. Existing demodulation
techniques were reviewed, with several of these simulated to find the most appropriate demodulation scheme for this application. This included the development of a new  detection scheme. A test system using Digital Signal Processing (DSP) techniques was constructed.