About the T-DMB/DAB Option
R&S
®
SMCVB-K156
14
User Manual 1179.1029.02 ─ 02
3.2.3
Transport Mechanisms
The DAB system is designed to carry several digital audio signals together with data
signals. Audio and data signals are considered to be service components which can be
grouped together to form services.
The DAB system transmission frame consists of three different channels:
●
Main Service Channel (MSC)
●
Fast Information Channel (FIC)
●
Synchronization Channel
3.2.3.1
Transmission channels
The MSC is a time-interleaved data channel used to carry the audio and data service
components, together with possible supporting and additional data service compo-
nents. The MSC is divided into a number of sub-channels. Each of the sub-channels is
individually convolutionally coded with equal or unequal error protection. Each sub-
channel may carry one or more service components.
The FIC is a non time-interleaved data channel with fixed equal error correction. FIC
carries information about the organization of the MSC sub-channels, such as informa-
tion on the multiplex structure and, when necessary, its reconfiguration. Optionally FIC
may include service information, conditional access management information and data
service.
The Synchronization Channel provides a phase reference and is used internally for
demodulator functions such as transmission frame synchronization, automatic fre-
quency control, transmitter identification, and channel state estimation.
The Synchronization channel, the Fast Information Channel and the Main Service
Channel form a transmission frame (see
). The MSC occupies the major part
of the transmission frame.
Figure 3-3: DAB transmission frame
Each transmission frame is divided into a sequence of OFDM symbols, each symbol
consisting of a number of carriers.
The Fast Information Block (FIB) and the Common Interleaved Frame (CIF) are intro-
duced in order to provide transmission mode independent data transport packages
associated with the FIC and MSC respectively.
About DAB/T-DMB
