Patent ID: 8255782
Filing Date: 2012-08-28
Classification: H03M

Abstract:
1. A method of constructing a LDPC code in a mobile digital multimedia broadcast system using a processor, wherein a Low-Density Parity-Check matrix of the LPDC code is iteratively constructed according to a code table and an expansion method, and the code-table is a part of the constructed Low-Density Parity-Check matrix, the method comprising the following steps: step 1: using the processor to set up a first cycle with a cycling index I with the I falls in the range of 1 to row number or column number of the code table, wherein the maximum value of the I is the row number of the code table if the code table is a part of rows of the constructed Low-Density Parity-Check matrix, and the maximum value of the I is the column number of the code table if the code table is a part of columns of the constructed Low-Density Parity-Check matrix; selecting data of I step 2: using the processor to nest a second cycle with a cycling index J in the first cycle in which J is selected from the range of 1 to L; wherein it is supposed that the dimension of the Low-Density Parity-Check matrix of the LPDC code is M rows and N columns, and the Low-Density Parity-Check matrix with M rows and N columns can be divided into m×n blocks with each block having L×L elements, i.e., M=m×L and N=n×L; if the code table is a part of rows of the constructed Low-Density Parity-Check matrix and it is supposed that the data sequence hexp corresponds to the r in which the symbol % denotes modular operation, and the row falls in the range of 1 to M; if the code table is a part of columns of the constructed Low-Density Parity-Check matrix and it is supposed that the data sequence hexp corresponds to the c in which % denotes modular operation, and the “column” falls in the range of 1 to N; step 3: using the processor to nest a third cycle with a cycle index K in the variable “row” of the second cycle with the K in the range of 1 to W, and the K if the code table is a part of rows of the constructed Low-Density Parity-Check matrix, the hexp (K) falls in the range of 0 to N−1, and the variable “column” is calculated according to the following formula: in which └•┘ denotes floor rounding operation; if the code table is a part of columns of the constructed Low-Density Parity-Check matrix, the hexp (K) falls in the range of 0 to M−1, and the variable “row” is calculated according to the following formula: setting the element at the row