Patent ID: 7945839

Claim:
A set-cyclic comparison method for a low-density parity-check decoder, which applies to a node unit with N input input elements, comprising the following steps: (a) initializing said elements, and sequentially removing said elements respectively at from a first position to N input th position to obtain N input pieces of lists to form a matrix with each said lists having (N input −1) said elements; (b) searching a upper half of said matrix to find out said elements having the maximum iteration number N iteration in a horizontal and vertical directions to form a first-type set with the corresponding said first-type set automatically presented in a lower half of said matrix; (c) sequentially updating dimensions of said first-type sets with said iteration number N iteration 2=N iteration 1−1 to repeatedly search for other said first-type sets, determining whether said iteration number equals to zero, performing the succeeding Step (d) if the result is positive, and returning to Step (b) if the result is negative; (d) from the remnant said elements not arranged into sets yet, adopting continuous said elements in the horizontal direction to form second-type sets, searching non-continuous said elements to find out symmetric non-boundary said elements, and combining each symmetric non-boundary said element with the most neighboring said element thereof to form an extra said second-type set; (e) finding out end-around neighboring said elements in the same row for each remnant boundary said element with the row calculation variable N row 2=N row 1+1, combining each remnant boundary said element with the end-around neighboring said elements thereof to form a third-type set; and (f) determining whether N row 2 equals to N input , ending the process if the result is positive, and returning to Step (d) if the result is negative.