Design of a bit interleaver for the high-order constellation DVB-T2 system

Since the DVB-T2 system provides high spectral efficiency among commercialized digital terrestrial transmission (DTT) systems, it has been considered as a prospective option for the base system of next generation DTT systems providing UHDTV service. However, when the high order modulation scheme such as 1024-QAM is employed, a bit interleaver in DVB-T2 should be newly designed. The design of a bit interleaver aims to improve the decoding performance not only by obtaining time diversity gain but also by eliminating multi-edge symbols. Although there are a few literatures about the design of a bit interleaver exploiting the multi-edge elimination, they cannot be directly applied to the bit interleaver of the DVB-T2 because they work as a group with a bit-to-cell demultiplexer. In this respect, this paper presents a bit interleaver design procedure for the high-order constellation DVB-T2 system. The proposed procedure generates bit interleavers for any modulation orders and makes it possible that a newly designed bit interleaver performs multi-edge elimination with all the LDPC code rates. Simulation results show that a newly designed bit interleaver for 1024-QAM achieves about 0.6dB SNR gain over a random interleaver under a Rayleigh fading channel.