Transmitter with waveform shaping and receiver with symbol synchronisation

摘要

A digital transmitter (70, 71) and a digital receiver (80, 81, 82, 83, 84, 85) are provided. The transmitter (70,71) is operable to generate a symbol waveform (61, 62, 63 or 64) for each symbol in digital data provided thereto to be transmitted, to combine a series of such waveforms to generate a combined waveform (60) and for modulating a carrier waveform with the combined waveform to generate modulated signals for transmission in short bursts from the transmitter without producing substantial spectral spreading. The receiver is operable to receive digitally modulated signals and produce therefrom corresponding symbol signals indicative of symbols present within the modulated signals, and to sample the symbol signals to provide a corresponding received data output signal from the receiver. The transmitter and receiver can be incorporated into a transmitting and receiving station (20, 21), a plurality of such stations at randomly distributed locations forming a telecommunication network. <IMAGE>