State diagram approach to feedback encoders for tailbiting codes
نویسنده
چکیده
—An algorithm for finding the starting state of a feedback tailbiting encoder is proposed, based solely on the properties of the encoder state diagram. With this approach, conditions for the existence of a tailbiting code generated by such an encoder are naturally tested in the process of preparing a certain permutation table for the starting state determination algorithm. A tailbiting failure for a given information sequence length L is detected when this table fails to be a permutation, which occurs if L is divisible by a length of any zero-branch cycle through nonzero states of the state diagram.
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