Patent ID: 6493845
Filing Date: 2002-12-10
Classification: H03M

Abstract:
A system for encoding codeword symbols in pairs in accordance with a generator polynomial g(x)=(xâˆ’&agr;L)(xâˆ’&agr;L+1) . . . (xâˆ’&agr;j+Râˆ’1), the system including:A. means for producing in a first stage of the system two values T0,j=&agr;L(cnâˆ’2j+&agr;L(cnâˆ’(2jâˆ’1)+T0,jâˆ’1)) {tilde over (T)}0,j=&agr;L(cnâˆ’(2jâˆ’1)+T0,jâˆ’1) where cnâˆ’2j and cnâˆ’(2jâˆ’1) are the pair of codeword symbols that are encoded during a jth clock cycle; B. means for producing in successive stages two to Râˆ’1 of the system two values Ti,j=Tiâˆ’1,j+&agr;L+i(cnâˆ’2j+{tilde over (T)}lâˆ’1,j+&agr;L+i(cnâˆ’(2jâˆ’1)+Ti,jâˆ’1)) {tilde over (T)}i,j={tilde over (T)}lâˆ’1,j+&agr;L+i(cnâˆ’(2jâˆ’1)+Ti,jâˆ’1), the system producing in stage Râˆ’1 at time kth the value TRâˆ’1,k which is a first redundancy symbol and 2k is the number of codeword information symbols;C. means for producing in stages 0 to Râˆ’2Vi,j=&Sum;b=0i&it;Î±L+b&it;Tb,k+jAnd in stage&it;â€ƒ&it;R-1=&Sum;i=0R-2&it;Î±L+i&it;Ti,k+j+Ïƒ&it;â€ƒ&it;TR-1,k+jwhere Ïƒ=&Sum;i=0R-1&it;Î±L+i,â€ƒsaid means producing at time k a second redundancy symbol VRâˆ’1,k; and D. means for feeding back to the stages the redundancy symbol values TRâˆ’1,k+j and VRâˆ’1,j, the system producing the remaining redundancy symbols cRâˆ’3, cRâˆ’4 . . . c1, c0 in pairs.