Data processing apparatus and method

摘要

A data processing apparatus is arranged to communicate data bits via a predetermined number of sub-carrier signals of Orthogonal Frequency Division Multiplexed (OFDM) symbols. The predetermined number of sub-carrier signals is determined in accordance with one of a plurality of operating modes. The data processing apparatus comprises a parity interleaver operable to perform parity interleaving on Low Density Parity Check (LDPC) encoded data bits obtained by performing LDPC encoding according to a parity check matrix of an LDPC code, the parity check matrix including a parity matrix corresponding to parity bits of the LDPC code, the parity matrix having a stepwise structure, so that a parity bit of the LDPC encoded data bits is interleaved to a different parity bit position. A mapping unit maps the parity interleaved bits onto data symbols corresponding to modulation symbols of a modulation scheme of the OFDM sub-carrier signals. A symbol interleaver is arranged in operation to perform an odd interleaving process which interleaves first sets of data symbols on to the sub-carrier signals of first OFDM symbols and an even interleaving process which interleaves second sets of data symbols on to the sub-carrier signals of second OFDM symbols. However, when the modulation mode is a mode which includes half or less than half a number of sub-carrier signals than a total number of sub-carriers in the OFDM symbols for carrying the data symbols that can be accommodated by the interleaver memory, the data processing apparatus is operable to interleave the data symbols from both first and second sets in accordance with the odd interleaving process on to the first and second OFDM symbols. The data processing apparatus can therefore communicate data bits via OFDM symbols of, for example DVB-T2 or DVB-C2.