A New Class of Selected Ternary Pulse Transmission Plans for Digital Transmission Lines

Digital transmission lines consisting of cable media and regularly spaced self-timed reconstructive repeaters are being considered for the transmission of binary digital information, such as arbitrary combinations of digitized speech, television, and data. For transmission over the line, the binary information is coded into a sequence of symbols. The transmission code is referred to as the pulse transmission plan. Among the significant practical problems which must be considered in choosing the pulse transmission plan are: 1) minimization of performance dependence on source statistics, 2) repeater timing jitter performance, 3) dc wander of the pulse stream, and 4) in-service performance monitoring. A new class of selected ternary pulse transmission plans has been devised to combat these problems. Emphasis in this paper is placed upon a member of this class, paired selected ternary (PST), in which the binary sequence to be transmitted is framed into pairs and translated into appropriately selected pairs of three level pulses.