Digital Terrestrial TV to North American ATSC Standard - Digital Video and Audio Broadcasting Technology - page 437

rored bytes are contained in a TS packet, Reed-Solomon error correction
fails, and the transport stream packet concerned is marked as errored.
To mark a TS packet as errored, the transport error indicator bit (Fig.
23.14.) in the TS packet header is set to 1. The packet in question will then
be discarded by the MPEG-2 decoder following the 8VSB demodulator in
the receiver, and the error will be concealed.

Sync byte 0x47

1 Bit Transport error indicator

184 byte
payload

4 byte
header

188 byte

Fig. 23.14. Transport error indicator in TS header

Precoder

Mapper

+

Z2

D

Z2 Z1 Z0 R
000 -7
001 -5
010 -3
011 -1
100 +1
101 +3
110 +5
111 +7

R

Z1

Data
out

.... ....

+

D D

Z0

Data in

Trellis coder

Coderate = datarate in / datarate out = 2/3

Fig. 23.15. Trellis encoder