A Synchronous Serial Data-Transmission System Using Orthogonal Groups of Binary Signal Elements

A theoretical analysis is presented of the tolerance to additive Gaussian noise of an adaptive data transmission system operating over a transmission path whose impulse response may vary slowly and over a wide range. Different detection processes and various transmitter and receiver filter characteristics are considered. The transmitted signal elements are separated into groups, with a sufficient time gap between adjacent groups to keep them orthogonal at the detector input. This paper is concerned with the performance of the detector when correctly matched to the channel. The adaptive techniques required to hold the detector in this condition have been described elsewhere and are not considered here. It is shown that the best of the detection processes achieves a good tolerance to additive noise, even in the presence of severe signal distortion, and that this detector is ideally suited for use with transmitter and receiver filters which introduce considerable intersymbol interference.