TABLE OF CONTENTS The following digital television broadcast systems are described in detail in Chapters 6, 7, 8, 9, 10. The main interest at this point is to call the reader s attention to the specific error-correcting codes employed by such systems (Drury et al., 2001, Francis and Green, 2007).
For error protection in the DVB-T system a concatenated forward error correction (FEC) scheme is used, as illustrated in Chapter 7. The randomized transport stream (TS) packets are encoded by an RS encoder for a (255, 239) RS code, the symbols of which are 8-bit bytes, i.e. the RS code is defined over GF(2 8). This means that 255 ? 239 = 16 check symbols are appended to the information bytes. This code allows correction of up to 16/2 = 8 symbols of corrupted data in a block of 255 symbols representing a code word that is a total of up to 64 bits within 8 corrupted bytes. As the TS packets are only 188 bytes long, the first 51 bytes are set to zero, but are not transmitted. Therefore, the actual RS code is a shortened (204, 188) code. The encoded bytes are then applied to a convolutional interleaver (Forney, 1971). Inner error protection is provided by a convolutional code. A non-systematic convolutional code with code rate 1/2 is used, with generator polynomials G 1 = (1, 1, 1, 1, 0, 0, 1),...
