World Broadcasting Unions Digital Radio User Manual - page 37
DIGITAL RADIO GUIDE
TERRESTRIAL TRANSMISSION SYSTEMS - ISDB-TSB
37
Figure 4.4: ISDB-TSB and full-band ISDB-T transmission
concept and its reception
(6)
Hierarchical transmission and partial reception
In the triple-segment transmission, both one layer transmission and hierarchical
transmission can be achieved. There are two layers of A and B in the hierarchical
transmission. The transmission parameters of carrier modulation scheme, coding
rates of the inner code and a length of the time interleaving can be changed in the
different layers.
The centre segment of hierarchical transmission is able to be received by single-
segment receiver. Owing to the common structure of OFDM segment, single-
segment receiver can partially receive a centre segment of full-band ISDB-T signal
whenever an independent program is transmitted in the centre segment.
Figure 4.5 shows an example of hierarchical transmission and partial reception. In
Japan, hierarchical transmission mode has to be used in the case of triple-segment
transmission.
Spectra
Data
Segment
ISDB-T transmission
ISDB-T
SB
Receiver
(Single-/triple-segment)
Sound / Data
HDTV
/ Data
Sound
/ Data
Sound
/ Data
ISDB-T
SB
transmission
ISDB-T Receiver
(full-band:13-segments)
Partial reception
Sound