A near-capacity MIMO-BICM scheme for digita terrestrial television broadcasting

Multiple-input multiple-output (MIMO) is one of the key technologies for the next generation digital terrestrial television broadcasting (DTTB). This paper proposes a near-capacity MIMO bit-interleaved coded modulation (BICM) scheme for DTTB systems. The amplitude phase shift keying (APSK) constellation with Gray mapping is applied to the BICM scheme. From the perspective of average mutual information, APSK has the advantage of shaping gain compared to its quadrature amplitude modulation (QAM) counterpart. Moreover, a new kind of bit interleaver named bit mapping, which takes into account the unequal error protection of both APSK and low-density parity-check (LDPC) codes, is proposed to further improve the system performance. The tool of extrinsic information transfer chart is utilized to help analyze and design the optimal bit mapping. Bit error rate simulations are carried out to verify the superiority of the proposed MIMO system.