Digital television broadcasting system using coded orthogonal frequency-division modulation with multilevel low-density-parity-check coding

摘要

In transmitter apparatus for a digital television broadcasting system, internet-protocol (IP) packets of digital television information are subjected to multilevel coding (MLC) before being Gray-mapped to quadrature-amplitude-modulation (QAM) constellations. The constituent codes of the MLC comprise respective low-density parity-check (LDPC) inner coding. Preferably, the LDPC inner coding is LDPC convolutional coding. The QAM constellations are used in coded orthogonal frequency-division modulation (COFDM) of plural carrier waves up-converted to a radio-frequency broadcast television channel. In receiver apparatus for the digital television broadcasting system the results of de-mapping QAM constellations recovered from demodulating the COFDM carrier waves are de-interleaved, and the LDPC constituent codes of the MLC are independently decoded in parallel with decoding results time-interleaved to recover the IP packets of digital television information.