Soft detection of modulation diversity schemes for next generation digital terrestrial television

The next generation of digital terrestrial television (DVB-T2) standard requires to improve performance of the current DVB-T standard. Commercial and technical reasons suggest that orthogonal frequency division multiplexing (OFDM) could still be adopted. As multiple–input multiple–output antennas techniques are not backward compatible with current constellations, new modulation methods suitable for OFDM in the presence of Rayleigh fading channels could be developed in order to provide diversity gain without spectral or power inefficiencies. In this paper we compare three modulation methods, namely, 1) re–mapped repetition, 2) rotational multi–carrier and 3) multidimensional rotated QAM, in a low–density parity–check (LDPC) block code scenario. As most of the modulation methods were introduced for an uncoded scenario, indeed it is seen that in the presence of coding, the bit error rate deeply differs from that in an uncoded scenario.