Patent ID: 6405343
Filing Date: 2002-06-11
Classification: H03M

Abstract:
A method for formation of Q-parity checkbyte values used for error control for a sequence of digital signal bytes that form a message, the method comprising:providing a sequence of R=MÂ·N digital signal elements s(r), numbered r=0, 1, . . . , Râˆ’1, where M and N are selected positive integers; for a selected value of a first index n1 in the range n1=0, 1, . . . , Nâˆ’1, receiving a first initial K-bit array s0{n1}=1Â·s(n1Â·M) and a second initial K-bit array s1{n1}=&agr;Â·s(n1Â·M), where K is 8 or 16; initializing a second index n2=0; for n1 fixed and n2=0, 1, . . . , Mâˆ’1, forming a first sequence s0{n1}=s0{n1}+1Â·s((n1Â·M+n2Â·(M+1)) (mod R)) and a second sequence s1{n1}=&agr;Â·s1{n1}+s((n1Â·M+n2Â·(M+1)) (mod R)), where 1 and &agr; are first and second selected K-bit arrays; repeating the preceding two steps for each of the sequence of values of n1=0, 1, . . . , Nâˆ’1; and processing the sequences {s0{n3}} and {s1{n3}}, with n3=0, 1, . . . , Nâˆ’1, to form first and second Q-parity checkbyte arrays {Q0{n3}} and {Q1{n3}} associated with the digital signal elements s(r), by a procedure comprising: providing selected powers &agr;h of the array &agr;, with h=230, 231, 232; initializing the index n3=0; forming the first and second arrays, Q0(n3) and Q1(n3), according to the relations Q0{n3}=&agr;230Â·s0{n3}+&agr;232Â·s1{n3} and Q1{n3}=&agr;231Â·s0{n3}+&agr;232Â·s1{n3}, for n3=0, 1, . . . , Nâˆ’1; and interpreting the arrays {Q0{n3}} and {Q1{n3}} as Q-parity checkbytes associated with the digital signal elements s(r).