DIGITAL RADIO GUIDE

TERRESTRIAL TRANSMISSION SYSTEMS - DRM

The combination of these techniques results in high quality sound in a narrow channel with robust reception in an intended coverage area with relatively low transmission power. In addition, source coding schemes using lower bit rates than that used with AAC/SBR are included for lesser levels of audio quality if the AAC/SBR quality level is not desired by a broadcaster. For example, a broadcaster may want to transmit two or more “speech” only programs. These would not require the full performance of AAC/SBR.

4.1.2Brief Description of the DRM System

(1)Overall design

Figure 4.1: Transmission Block Diagram

audio data stream

data stream

FAC information

source

encoder(s)

pre-coder

pre-coder

normal prot.

[high prot.]

normal prot.

[high prot.]

MUX

normal/[high] protection

energy dispersal

energy dispersal

channel encoder

channel encoder

cell

interleaver

pilot generator

MSC

FAC

OFDM cell mapper

OFDM signal generator

modulator

DRM transmission signal

SDC information

pre-coder

energy dispersal

channel encoder

SDC

flow of information

Figure 4.1 depicts the general flow of different classes of information (audio, data, etc.) after their origination in a studio or control centre (that would be depicted to the left of the figure) to a DRM transmitter exciter/modulator on the right. Although a receiver diagram is not included in the figure, it would represent the inverse of this diagram.

There are two classes of basic information:

•the encoded audio and data that are combined in the main service multiplexer;

•information that bypasses the multiplexer that are known as fast access channel (FAC) and service description channel (SDC), whose purposes relate to identification and control for a transmitter and for appropriate decoding selection within a receiver.

The audio source encoder and the data pre-coders ensure the adaptation of the input streams onto an appropriate digital format. Their output may comprise two parts requiring two levels of protection within the subsequent channel encoder.

The multiplex combines the protection levels of all data and audio services in a proper format within the frame structure of the bit stream.

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Grundig Digital Radio manual Brief Description of the DRM System, Overall design
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Digital Radio specifications

The Grundig Digital Radio represents a significant advancement in radio technology, combining aesthetics, functionality, and a user-friendly interface. As a pioneer in the audio and electronics industry, Grundig has successfully integrated modern digital capabilities into its traditional radio design, appealing to both nostalgic listeners and tech-savvy users.

One of the standout features of the Grundig Digital Radio is its versatility in reception. With DAB+ (Digital Audio Broadcasting) technology, users can enjoy a wide array of radio stations with superior sound quality, free from the hiss and interference commonly associated with analog broadcasts. The inclusion of FM and AM bands ensures that listeners are not limited, providing access to local stations that may not yet have transitioned to digital.

The Grundig Digital Radio is designed with ease of use in mind. Its intuitive interface, often featuring a clear LCD display, allows users to navigate through stations and settings effortlessly. Many models also include a built-in tuner that automatically scans and presets available stations, simplifying the setup process. For those who appreciate personalization, some variants come equipped with customizable presets, allowing users to save their favorite stations for quick access.

Portability is another key characteristic of the Grundig Digital Radio. Many models are lightweight and come with built-in handles, making them ideal for on-the-go listening, whether it's in the garden, on the beach, or during a picnic. Battery options, alongside mains power, ensure that users can take advantage of their radios wherever they choose.

In terms of sound quality, Grundig utilizes advanced audio technologies to deliver rich and clear sound. Enhanced bass responses and treble controls allow users to fine-tune their listening experience to match their preferences. Furthermore, many models feature additional inputs, such as AUX and USB ports, enabling users to connect their smartphones or other devices, expanding their audio options.

Other notable characteristics include built-in alarms and timers, which make the Grundig Digital Radio a versatile companion for daily routines. Some models even support Bluetooth connectivity, allowing for seamless streaming from a variety of devices.

In summary, the Grundig Digital Radio embodies the perfect blend of traditional radio appeal and modern digital technology, offering versatility, ease of use, superior sound quality, and portability to meet the diverse needs of today’s listeners. Its well-thought-out features and user-friendly design make it an excellent choice for anyone looking to enhance their audio experience.
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