The invention relates to error-correcting coding and correct restart of decoding after errors of sequences that are coded by convolutional coders or LFSR based descramblers. The signals can be binary or multi-valued signals. Methods and apparatus to convolutional encode and decode sequences of binary and n-valued symbols are disclosed. The invention further discloses methods and apparatus to identify symbols in error in sequences coded according to methods of the invention. Methods and apparatus to correct these errors are provided. Methods and apparatus to repair errors in a Trellis of received sequences are also provided. Methods and apparatus for n-valued Recursive Systematic Convolutional coders and decoders are disclosed.