A circular Viterbi algorithm for decoding tailbiting convolutional codes

These algorithms are used in blockwide transmission to save the overhead of a known tail. The basic ideas are: (1) continue conventional seamless continuous Viterbi decoding beyond the block boundary by recording and repeating the received block of (soft) symbols; (2) start the decoding process in all states; and (3) end the decoding process either adaptively or with a fixed length. Three robust adaptive stopping rules are constructed and evaluated. Simulation results and a comparison to previously known algorithms are presented