Patent ID: 6272187
Filing Date: 2001-08-07
Classification: H03M,H04L

Abstract:
A device which decodes data encoded with a cyclic code in communications svstems where a convolutional code is applied after the cyclic code during encoding, comprising:a decoder which decodes the convolutional code; anda cyclic redundancy check circuit comprising a plurality of linear feedback shift registers having a plurality of feedback paths,wherein the device is configured to accept data provided in time reversed order, andwherein a set of multipliers corresponding to a set of coefficients is interposed in the feedback paths such that when data is shifted through the feedback shift registers, the device performs division by x for an input bit equal to 0, and, for an input bit equal to 1, performs division by x and then adds x.sup.k+m-1, where x is a variable of a generating polynomial g(x)=g.sub.k x.sup.k +g.sub.k-1 x.sup.k-1 + . . . +g.sub.1 x+g.sub.0, k is the highest order of the generating polynomial, and m is the total number of input bits to be decoded.