Abstract: A Turbo decoder and method for decoding a double-binary circular recursive systematic convolutional (DBCRSC) encoded signal with unknown initial and final states executes iterations of forward and backward recursion on a payload block of the DBCRSC encoded signal and a padded block using an estimated forward state metric (FSM) and an estimated backward state metric (BSM), which are updated at one or more iterations.

Abstract: A decoder and method for decoding a tail-biting convolutional encoded signal using Viterbi decoding scheme performs a traceback operation for a first portion of a total code block, which includes a code block of the tail-biting convolutional encoded signal and a padded block. During the traceback operation for the first portion, a particular state at a predefined position within the first portion is stored as a circular state. The circular state is used as a traceback starting state for at least one subsequent portion of the total code block to produce a decoded signal of the code block.