Low-Rate LDPC Code Design for DTMB-A

Digital terrestrial television multimedia broadcasting-advanced (DTMB-A) proposed by China is served as a 2nd generation digital terrestrial television broadcasting (DTTB) standard with advanced forward error correction coding schemes. Nevertheless, to adapt low signal-to-noise ratio (SNR) scenarios such as in cloud transmission systems, LDPC codes with low rates are required for DTMB-A. In this paper, the new design of low-rate DTMB-A LDPC codes is presented systematically. Specifically, a rate-compatible Raptor-Like structure of low-rate DTMB-A LDPC codes is presented, which supports multiple low code rates with constant code length. Then a new construction method is proposed for low-rate DTMB-A LDPC codes, where progressive block extension is employed and the minimum distance is majorly optimized such that the minimum distance increases after each block extension. Finally, the performance of the constructed DTMB-A LDPC codes with two low code rates of 1/3 and 1/4 are simulated and compared with ATSC 3.0 LDPC codes, which demonstrates the effectiveness of our design.