Abstract: A succession of (k+n)-bit input words are coded for transmission over a (1 - D) partial response channel by applying n of the bits of each word to a trellis coder which, in turn, selects one of a plurality of 2.sup.m cosets from a predefined lattice, where M>n. A signal point, or "seed," is then selected as a function of both (a) the values of the other k bits and (b) the value, referred to as the "channel state", of the last pulse in the previous signalling interval, in such a way as to ensure that the signal point presented to the receiver is a point in the selected cost. Viterbi decoding on the cosets is then used in the receiver to recover the most likely sequence of transmitted signal points and, in turn, the (k+n)-bit input words.

Abstract: A method and associated system for providing multi-channel transmission of digital and broadband video information in optical fiber communication for local area networks through frequency-division-multiplexing, comprising the steps of generating a plurality of closely spaced optical carrier wave pairs with the optical carrier waves within each optical carrier wave pair having a predetermined separation frequency between one another, assigning each of the plurality of optical carrier wave pairs to a predetermined frequency slot and optically combining the plurality of optical carrier wave pairs to provide a multiplexed optical output wave. Advantageously, in addition to direct detection the plurality of optical carrier wave pairs may be detected by opto-electronic heterodyne detection and/or incoherent optical-heterodyne detection to electronically recover the optical carrier wave pairs.