DAB is now being made available across the range of the Automotive market, from VW campers to top of the range Audis *** More than 45 different combined DAB/DAB+ receiver models commercially available *** Sub €30 DAB radios are available to all via web sites such as Amazon *** DAB+ allows approximately 20 audio services to be broadcast within a single Eureka 147 transmission *** Did you know that in countries where DAB/DAB+ is fully established, it is the fastest growing of all digital platforms? *** Did you know that analogue listening has been losing market share over the last 10 years, while all digital platforms are on the rise? *** DAB Slide show pictures enables advertisers to couple pictures with audio magnifying consumer brand awareness ***

Outline of the DAB System

Generation of the DAB Signal | Reception of a DAB signal

Generation of the DAB Signal

You will see in Figure 1 how each service signal is coded individually at source level, error protected and time interleaved in the channel coder. Then the services are multiplexed in the Main Service Channel (MSC), according to a pre-determined, but adjustable, multiplex configuration. The multiplexer output is combined with Multiplex Control and Service information, which travel in the fast Information Channel (FIC), to form the transmission frames in the Transmission Multiplexer. Finally, Orthogonal Frequency Division Multiplexing (OFDM) is applied to shape the DAB signal, which consists of a large number of carriers. The signal is then transposed to the appropriate radio frequency band, amplified and transmitted.

Fig. 1 Generation of the signal

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Reception of a DAB signal

Figure 2 demonstrates a conceptual DAB receiver. The DAB ensemble is selected in the analogue tuner., the digitised output of which is fed to the OFDM demodulator and channel decoder to eliminate transmission errors. The information contained in the FIC is passed to the user interface for service selection and is used to set the receiver appropriately. The MSC data is further processed in an audio decoder to produce the left and right audio signals or in a data decoder (Packet Demux) as appropriate.

Fig. 2 Conceptual DAB receiver

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