Implementation of an experimental modem for cellular mobile radio channels

The design, simulation, and implementation of a modem specifically for use on mobile radio channels at frequencies allocated to the existing UK cellular system is described. In particular a novel technique for transmitting two phase-modulated digital signals from two mobile vehicles on nominally the same carrier frequency, and performing detection and separation of them at the receiver is covered. The potential application of this system in cellular mobile radio is discussed, together with an assessment of typical improvements in system capacity that might be achieved.