CYCLIC COMPARISON METHOD FOR LOW-DENSITY PARITY-CHECK DECODER

Abstract

The present invention discloses a cyclic comparison method for an LDPC decoder, which applies to the comparators used in an LDPC decoder. According to the cyclic comparison algorithm of the present invention, the nth element of the input k elements, wherein n=1, . . . , k, is sequentially removed by the corresponding comparator to obtain k first series. Next, pairs of two elements selected from the k elements are used to form k second series. The preceding step is repeated k×log2(k−1) times to obtain k completion series. Either of one first series and one completion series contains (k−1) elements. The first series are compared with the completion series to determine whether they are identical. If they are identical, the process stops. If they are not identical, the abovementioned step is repeated to obtain new completion series. The cyclic comparison method of the present invention needs only k×log2(k−1) comparisons to obtain completion series. Thus, the present invention can reduce the number of basic operations and can apply to any input number. Further, the present invention can be easily programmed and can achieve the optimal solution.