Data processing apparatus and method

摘要

A data processing apparatus is arranged in operation to recover data bits from data symbols received from a predetermined number of sub-carrier signals of an Orthogonal Frequency Division Multiplexed (OFDM) symbol to form an output bit stream. The data processing apparatus comprises a symbol de-interleaver operable to read-into and out from the predetermined number of data symbols from the OFDM sub-carrier signals in accordance with a set of addresses, with the effect that the data symbols are de-interleaved from the OFDM sub-carrier signals into the output symbol stream. A de-mapping unit is operable to generate from the data symbols of the output symbol stream parity interleaved LDPC encoded data bits by converting each of the data symbols of the output symbol stream representing a modulation symbol of the OFDM sub-carrier signals into data bits corresponding to a modulation scheme. An inverse permuter is adapted to perform an inverse permutation process so that a plurality of the LDPC encoded data bits corresponding to a value of 1 in an arbitrary row of an information matrix corresponding to information bits of an LDPC code, which was used to encode the data bits, is not incorporated into the same symbol. An LDPC decoder is adapted to perform LDPC decoding on the LDPC encoded data bits on which the inverse permutation process has been performed to form the output data bits. The symbol de-interleaver includes an address generator operable to generate the set of addresses. The set of addresses are generated by an address generator which has been optimised to interleave the data symbols on to the sub-carrier signals of the OFDM carrier signals for a given operating mode of the OFDM system, such as a 4K operating mode for DVB-T2 or DVB-C2.