What is digital radio technology (DAB)?

Here are the basics of DAB - Digital Audio Broadcasting, a form of radio technology being used in some countries .

What is DAB technology?

DAB Digital Radio, also known as digital audio broadcast, is a completely new system for broadcasting and receiving stations.

As the name suggests, signals broadcast in a digital format allow CD quality to be achieved. Those who have listened to the digital radio DAB have commented on the significantly better sound quality and "presence" of the new radio system. Also it does not suffer from the multiple effects often experienced on FM transmissions and the system uses what it is called a single frequency network (SFN) without having the necessary retuning when moving from a coverage area. next wave

In addition to this many new services can be implemented on digital radio stations that allow new systems to fit into the 21st century. Digital radio signals carry data along with sound, and This allows text and images to be transmitted with sound to enhance the listening experience. In this way, it can convey the title of a song, and a photo of the artist while some music is being transmitted. It can also have moving news on the bottom of the screen used on radio stations.

This is a completely new system for broadcasting and receiving stations.

DAB digital radios are now established in many countries around the world from the United Kingdom and Europe to Canada, Australia and many other countries.

The digital radio works DAB

In order to produce a digital system that satisfactorily operates according to the conditions required for digital radio a large number of jobs have been performed during the development phase. A number of current digital techniques have been studied but it has realized significant limitations for this application.

One of the main problems is that many recipients will use non-directional antennas and as a result they will receive a reflected signal. These will be delayed enough for the faulty data. Also the bandwidth required to accommodate a full stereo signal will need to be reduced to ensure efficient use of the spectrum. C

Technical standards for digital radio were developed under the auspices of the European Eureka Project 147. The group includes producers, research stations and network operators. .

There are two main areas of the system that are interested in digital broadcasting: that is the modulation system and the digital audio coding and coding system.

System coding and compression is very important. For systems to be able to develop data rates have been significantly reduced compared to standard CDs. The digital radio system adopts a data rate reduction of 128 kbits / sec, a sixth of the bit rate for the same quality as the encoded linear signal. To achieve the input audio signal reduction is carefully analyzed. It is found that the ear has a certain threshold of hearing. Below is the signal that is not heard.

Also if a strong sound is presented on a sound frequency then weakly close it may not be heard because the hearing threshold is modified. By analyzing the sound to and only coding the components that the ear will hear significantly reduced can be done. Continued reduction of data rate can be achieved by reducing audio bandwidth. This is done on some channels as users only for speeches.