Improved system and method for decoding tail-biting code especially applicable to digital cellular base stations and mobile units.

摘要

A digital cellular system (10) employs a decoder that decodes control messages encoded by a convolutional tail-biting encoding procedure. The control messages (57) contain 65 bits that are encoded in a 260 bit data frame (59). The decoder reads (112) the first X quadruple bits and writes them also at the end of the data frame bit stream. A Viterbi decoding algorithm (114) is applied to the modified bit stream for X plus 65 steps. A bit stream of (65+X) bits is selected (116) from a best value path and y first bits are discarded from the selected stream. The output decoded message (118) includes bits (y+1) through (y+65).