Patent ID: 7178084

Claim:
A data coding method comprising: (a) coding an input sequence (b 0, b 1, b 2 , . . . , b k−1 ) to produce a codeword c=(c(−r), c(−r+1), . . . , c(−1), c(0), c(1), . . . , c(k−1)), where for 0≦i ≦k−1, c(i) is determined according to the following: c ( i ) f 0= c ( i )= b ( i )⊕ c ( i− 1)f 1 ⊕c ( i− 2)f 2 ⊕ . . . ⊕c ( i −r )f r where c i and b i are corresponding user data and codeword bits at time i; (b) for each of a plurality of input sequences, independently selecting appropriate initial conditions (c(−r), c(−r−1), . . . , c(−2), c(−1)) to satisfy a predetermined property in the codeword coded according to (a); and (c) outputting codewords coded using the appropriate initial conditions; wherein: k=64, r=1 or 2, and, f 2 =1=f r .