SIMPLE DECODING METHOD FOR CONVOLUTION CODE AND SIMPLE DECODING CIRCUIT

摘要

PURPOSE: To implement simple decoding for a convolution code with a desired bind length and a coding rate n/m. ;CONSTITUTION: Convolution code data for each of m(=4) bits fed to a decoding circuit are given respectively to m-sets of shift registers SR₁-SR₄ by one bit each having shift stages of x=[(K-1)/(m-n)] in series connection, where [p] is a minimum integer over a real number (p). The combination of n(=3) sets of mod2 adders (23₁-23₄) is specified by all shift stages (#1-#24) and n-sets of decoding generating vectors specifying n-sets of decoding generation polynomials and each mod 2 adder applies mod2 addition to outputs of the combined shift stages and n-sets of addition results are outputted as decoding result in n-bits. n-sets of decoding generating vectors have n-rows of consecutive elements selected from N-rows of decoding generating vectors obtained from an inverse matrix of a square matrix using N×N sets of coefficients specifying N-mx(=24) sets of convolution code generation polynomials as elements as coefficients respectively.;COPYRIGHT: (C)1993,JPO&Japio