A method for coding a data signal for transmission and reception which includes the steps of generating a prefix signal which is a train of pulses at a multiple or submultiple of a selected baseband frequency, then generating a data stream following said prefix with the data stream having one binary...http://www.google.com/patents/US4569060?utm_source=gb-gplus-sharePatent US4569060 - FSK Coding method and apparatus involving multiples and submultiples of a given frequency
