DIGITAL RADIO GUIDE

APPENDIX A: EUREKA 147

Table A.2: Example of possible number of programs

Audio data

 

Protection level (increasing protection)

 

rate (kbps)

5

4

3

2

 

1

 

 

 

 

 

 

 

24*

N/A

64

48

36

 

24

32

54

41

36

29

 

24

 

 

 

 

 

 

 

64

27

20

18

14

 

12

128

13

10

9

7

 

6

 

 

 

 

 

 

 

192

9

7

6

5

 

4

 

 

 

 

 

 

 

224

7

6

5

4

 

3

256

6

5

4

3

 

3

 

 

 

 

 

 

 

* At most audio data rates, Eureka 147 uses Unequal Error Protection an error protection procedure which allows the bit error characteristics to be matched with the bit error sensitivity of the different parts of the audio frame. At the lowest data rate, 24 kbps, Eureka 147 uses Equal Error Protection, an error protection procedure which ensures a constant protection of the bit stream.

Audio Quality

ITU R Recommendation BS.1115 specifies use of MPEG 1 Layer II at 256 kbps (stereo mode), for broadcast applications requiring CD quality. This recommendation is based on subjective listening tests undertaken in 1992. At the time, MPEG 1 Layer II at 192 kbps (joint stereo mode) was also tested but was found to only marginally meet the audio quality requirement. Additional tests in 1993 failed to reveal sufficient improvement in the codec to warrant inclusion of this lower data rate in the ITU recommendation.

Further listening tests were performed in 1995, as part of the US Electronic Industries Association’s (EIA) evaluation of digital radio systems. A range of audio coding systems were tested including MPEG 1 Layer II at 224 and 192 kbps (joint stereo modes). The findings of this work indicate the MPEG 1 Layer II codec at 224 kbps is capable of meeting the basic audio quality criteria specified by the ITU R. The lower rate of 192 kbps again failed to meet the required quality.

Spectrum Issues

Eureka 147 Channel Plans

In 1995, the introduction of terrestrial Eureka 147 was discussed by the European Conference for Posts and Telecommunications (CEPT) in Wiesbaden.17 In cooperation with representatives of regional and international organisations such as the EBU, the European Commission and the ITU a total of 73 channels to be used for future and current digital audio broadcasting services was agreed. Each channel is 1.536 MHz wide with appropriate guard bands between each channel and at the edge of each band.

17Final Acts of the CEPT T_DAB Planning Meeting (3)”, Maastricht 2002,CEPT, http://www.ero.dk/52EB3135-F356-49FF-A970-B32D2C745921?frames=0

97

Page 96 Page 98
Page 97
Image 97
Grundig Digital Radio manual Table A.2 Example of possible number of programs, Audio Quality
Page 96 Page 98

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.
Top Page Image Contents