Patent ID: 9130814
Filing Date: 2015-09-08
Classification: H03M,H04L

Abstract:
1. An interleaving method performed by a transmitter for a communication system with quasi-cyclic low-density parity-check codes, spatial multiplexing, and T transmit antennas, T being an integer greater than 1, the interleaving method being used for applying bit permutation to bits of a codeword of a quasi-cyclic low-density parity-check code in order to generate a plurality of constellation words constituting a plurality of spatial-multiplexing blocks from the codeword, the codeword consisting of N cyclic blocks, and each cyclic block consisting of Q bits, each spatial-multiplexing block consisting of B bits and consisting of T constellation words, the interleaving method comprising: a first permutation step of permuting the N cyclic blocks of the codeword; and a second permutation step of permuting the bits of the codeword, whose N cyclic blocks have been permuted, so as to map the bits to the T constellation words constituting each spatial-multiplexing block, wherein T=2, N=45, Q=360, and B is 6, the N cyclic blocks are divided into a plurality of sections each including B/2 cyclic blocks, a transmission power ratio is 1/1, the quasi-cyclic low-density parity-check code is a code defined by the DVB-NGH standard with a code rate of one of 7/15, 8/15, and 3/5, the bits of each spatial-multiplexing block are divided into a 4-QAM constellation word and a 16-QAM constellation word, and permutation in the first permutation step is applied according to cyclic block permutation shown in Table 1, in accordance with the code rates of the quasi-cyclic low-density parity-check code: permutation in the second permutation step is applied such that, the two bits of the 4-QAM constellation word are made up of bits of the first cyclic block of the respective section, the two bits of the 16-QAM constellation word having the lowest reliability are made up of bits of the second cyclic block of the respective section, and the two bits of the 16-QAM constellation word having the highest reliability are made up of bits of the third cyclic block of the respective section.