HD radio?

Техника и технология
Димитър

HD radio?

Мнениеот Димитър » 19 Окт 2006, 07:31

Някой чувал ли е за това животно HD радио - цифрово радиоразпръскване заедно с аналоговото с допълнителни 1 или 2 програми освен основната на същата честота?
случайно попаднах на това, изглежда засега като да е само в щатите, описанието е в типичния за тях стил - къде се намирате = в кой щат сте, друг свят не съществува :)
все пак е интересно дали тази технология ще се разпространи в Европа и у нас?

повече инфо тук:
http://hdradio.com/index.php
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HD radio?

Мнениеот radiator » 19 Окт 2006, 12:15

Правиха тестове рпеди месец и нещо в Швейцария, но като цяло стратегията в Европа изключва HD. Eureka-147 e стандартът, който ще се развива.
Иначе същността на HD е малко по-различна. Модулира се цифров сигнал, като се използва същия честотен диапазон, а ако приемеш с аналогово радио HD сигнал се чува едно странно свистене. В зависимост от битрейтите, може да побереш до 3 програми.
MR1

Re: HD radio?

Мнениеот MR1 » 22 Окт 2007, 23:04

A vo koi strani ima HD radio?
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Re: HD radio?

Мнениеот ogibo » 22 Окт 2007, 23:35

За сега май само в Северна Америка.
MR1

Re: HD radio?

Мнениеот MR1 » 23 Окт 2007, 01:08

Иначе интересно е това ако со обичен ФМ приемник хвадиш HD Radio частота че
има интересен звук нешто како GSM телефон доближен до TV
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Re: HD radio?

Мнениеот radiator » 23 Окт 2007, 12:08

Да, може да се оприличи на такъв звука.

Като цяло в ЕС стратегията е за развитие на Т-ДАБ. Има тестове на НД в Швейцария, като цяло обаче май няма да видим комерсиално НД в Европа.
MR1

Re: HD radio?

Мнениеот MR1 » 23 Окт 2007, 12:20

A зошто се нарекува HD радио? Звукот да не е со 512 или 1024 kbit/s  :D
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Re: HD radio?

Мнениеот radiator » 23 Окт 2007, 13:47

Просто така са решили създателите. МОжеш ли да кажеш защо Фокс е Фокс - сигурно има защо.. създателите имат право да си дават имена  :Old
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Re: HD radio?

Мнениеот luboj » 08 Мар 2008, 01:37

тва е такава изгъзица...
а самото наименувание е просто запазена марка на няква фирма избрана от тукашното СЕМ
и не означава High Definition ами Hybrid Digital
мега корпорации като Clear Channel се опитват се да се борят със сателитното радио на XM и Sirius
които, поне доста от каналите им, са 256-384kbps

http://en.wikipedia.org/wiki/HD_Radio
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Re: HD radio?

Мнениеот ЖОРО » 09 Мар 2008, 08:40

В германия се правят тестове на 102.7 има 3 радио станции с по 160Kbps
В Холандия също но не помня 4естотата като програми са 538,CAZ!
Швеция тества
Дания -- тествала и отказала
България тествала и отказала !! застава твърдо зад DAB
Франция - OK
Люксембург - отказзз
ПОлша ще тества през Юни
Последна промяна 1 на ЖОРО, променена общо 9 пъти
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Re: HD radio?

Мнениеот ЖОРО » 09 Мар 2008, 08:45

ЖОРО написа:В германия се правят тестове на 102.7 има 3 радио станции с по 160Kbps
В Холандия също но не помня 4естотата като програми са 538,CAZ!
Швеция тества
Дания -- тествала и отказала
България тествала и отказала !! застава твърдо зад DAB
Франция - OK
Люксембург - отказзз
ПОлша ще тества през Юни

Radio Regenbogen Launches First HD Radio™ Test in Germany
Columbia, Maryland, August 15, 2007 -- Radio Regenbogen, one of Germany’s private radio stations, and network operator Media & Broadcast of T-System have announced that they will begin an HD Radio technology field test at the end of August.

“Listeners in the Rhine-Nectar area will be able to receive the Radio Regenbogen program as in the past with their normal radio at a frequency of 102.8,” commented Radio Regenbogen’s managing director, Gregory Spaceman in a press release. “With the new HD Radio technology, they will also be able to enjoy the new formats ‘Regenbogen Gold and Regenbogen Comedy,’ two new multicast channels.”

Testing is also being supported by iBiquity Digital, Audioexport Georg Neumann, Orban/CRL Systems and Broadcast Electronics and Ruoss AG, a company that has assisted with HD Radio tests in Switzerland. The first test results are to be presented at an event of the Regional Office for Communication that will be held in Stuttgart on September 27, 2007. For more information, please visit: http://www.regenbogenweb.de/.

International HD Radio testing and adoption has accelerated in recent months as evidenced by the following developments: In May 2007, Mexico's Federal Telecommunications Commission allowed radio stations along the country's northern U.S. border to voluntarily begin broadcasting with HD Radio technology; in March 2007, more than 70 executives from the automotive, broadcast, data content, and semiconductor industries participated in the HD Radio Forum held in Cologne, Germany; R.V.R. Elettronica became the first licensed HD Radio broadcast equipment manufacturer in Europe in February 2007; and in November 2006, Brazilian broadcasters formed the "Brazilian Alliance for Digital Radio" to promote and support the deployment of HD Radio technology in that country.

About iBiquity Digital
iBiquity Digital Corporation is the developer of the HD Radio system which is powering the AM/FM digital radio revolution. This transformational technology allows AM and FM stations to broadcast digital signals in tandem with their analog signals, providing broadcasters with a platform to deliver multiple channels of programming
on the same frequency (HD2 multicasting); crystal-clear, CD-quality sound; advanced services such as traffic updates; and text and graphics content. More than 1,300 U.S. HD Radio stations are on the air, with more than 600 of those offering additional content via multicast channels. HD Radio technology is being or has been tested in many countries throughout the world, including Argentina, Australia, Bosnia, Brazil, Canada, Czech Republic, France, Hong Kong, Indonesia, Mexico, New Zealand, Philippines, Poland, Switzerland, Thailand and Ukraine. iBiquity’s investors are global leaders in the technology, broadcasting, manufacturing, media and financial industries.

To arrange interviews or for additional information, please contact:
Vicki Stearn Gil Chorbajian
iBiquity Digital Ogilvy Public Relation
443-539-4345 518-355-0966
[email protected] [email protected]

###



HD Radio & FMeXtra systems being tested in Europe

4th September 2007

A few stations in countries such as Norway, Italy, Holland and Germany have recently been testing two US-based digital radio standards, called HD Radio and FMeXtra.

Although you can't blame the US companies for trying to push their proprietary digital radio systems in Europe, I personally don't think they have much chance of getting their systems adopted on a large-scale basis across Europe due to most countries already having committed to using one of the Eureka 147-based systems -- i.e. DAB, DAB+ or DMB -- albeit that some countries aren't showing any interest in properly launching digital radio.

DAB receiver manufacturers would be opposed to supporting these other standards, because the licensing costs and additional hardware costs required for these proprietary US-based systems would eat into their profit margins, so unless HD Radio and/or FMeXtra can manage to persuade a substantial number of radio stations to use their systems in Europe, the receiver manufacturers will simply ignore them.



HD Radio

HD Radio is the US equivalent of DAB in the UK, in that it is the terrestrial digital radio system that the broadcasters have chosen to use to replace FM. 'HD Radio' is actually a brand name, and 'HD' used to stand for 'hybrid digital', apparently, and not high-definition, and I'm sure it's just an amazing coincidence that they've named their digital radio system using the same initials as those that are synonymous with higher quality on TV.

HD Radio is a proprietary system that was developed by Ibiquity, which is an off-shoot from Lucent Technologies, and HD Radio signals are transmitted in the guard bands in between existing FM or AM stations' signals. As of July 2007, there were 1,360 stations in the US broadcasting an HD Radio signal, and it is claimed that HD Radio transmissions don't interfere with the existing FM stations, although some listeners disagree.

Like DAB and most other digital broadcasting systems, HD Radio uses OFDM modulation, but unlike DAB, it uses a modern efficient audio codec called HDC, which is a proprietary codec developed by Ibiquity that uses Spectral Band Replication (SBR), which is the key technology that makes the AAC+ audio codec so efficient. I've not been able to find any details about what error correction coding is used on HD Radio due to the system being proprietary.

An HD Radio signal has a capacity of 96 kbps if the FM station wants the HD Radio signal to have a similar coverage area as the FM station, or it can carry up to 147 kbps if the broadcaster is willing to accept the HD Radio signal having a smaller coverage area than the FM station it is piggy-backed to -- 96 kbps is expected to be the capacity used by the vast majority of stations. It is claimed that a station broadcasting at 96 kbps using the HDC will provide near CD-quality, and HDC is supposed to be almost as efficient as the AAC/AAC+ audio codec.

HD Radio has stolen and bastardised the term "multicasting" and used it to refer to the situation where the 96 kbps is split between more than one station -- 'multicasting' is an Internet term which refers to the very efficient way that live Internet streams are distributed where only one stream is sent irrespective of the number of listeners in comparison to the current way Internet streams are delivered using 'unicast' where one stream is sent per listener, which is exceptionally inefficient in terms of the bandwidth consumed. It is envisaged that stations using 'multicasting' will split the 96 kbps between two stations either using 48/48 kbps or 64/32 kbps. HD Radio can also broadcast a single surround sound station in the 96 kbps capacity, which will presumably make use of the new MPEG Surround format, which allows surround sound information to be added at very low bit rates such as 5 - 32 kbps, or maybe Ibiquity has developed its own format -- again, due to the system being proprietary, it's not easy to find out this kind of information.

HD Radio transmissions are synchronised with the FM signal that they're piggy-backing on, and receivers are designed to fall back to the FM station if the signal level of the digital signal falls below a certain threshold.

When FM is eventually switched off, the capacity of the HD Radio signal will increase dramatically due to the higher bandwidth that the signal can use.



FMeXtra

Unlike HD Radio, where the digital signal is a separate transmission from the FM station's transmission, FMeXtra transmissions are actually part of the FM signal itself. For example, the following figure shows the baseband signal with the mono signal (L+R) at the lowest frequencies, then the stereo part (labelled L-R) followed by the FMeXtra signal (labelled Digital SCA, which stands for 'Subsidiary Communications Authority') at the higher end of the baseband spectrum. The combined basedband signal is then FM modulated:





An FM receiver that supports FMeXtra would then perform FM demodulation to (ideally) recover the baseband spectrum as shown above, and the FM signal can be recovered as follows:

Left channel = 0.5 x ((L+R) + (L-R)) = L

Right channel = 0.5 x ((L+R) - (L-R)) = R

as well as the FMeXtra signal being available for error correction and audio decoding.

FMeXtra also uses OFDM modulation and although it is a proprietary system there are more details available about the other technologies it uses, such as that it employs the strongest form of error correction coding available called turbo coding, and it uses the very efficient AAC+ audio codec.

In the configuration shown in the figure above, where the FM station is using stereo, a capacity of 64 kbps is available to be used for one or more digital radio stations to use but only if RDS is switched off, and if RDS is still transmitted -- the vast majority of European radio stations use RDS for station names etc -- the capacity available would be limited to just 40 kbps, which when using AAC+ would provide the similarly low audio quality to 128 kbps MP2 on DAB.

In the US, splitting the 64 kbps between more than one digital station would result in low audio quality, so hopefully if FMeXtra is adopted by anybody they'll limit the number of digital stations to one. If the FM station is limited to broadcasting in mono the capacity for the FMeXtra signal increases to 128 kbps.
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Re: HD radio?

Мнениеот ЖОРО » 09 Мар 2008, 08:47

Broadcast Electronics (BE) has installed an HD Radio?????? FM system on an independent station in Paris, France. TowerCast, in partnership with independent broadcast syndicate SIRTI and NRJ Group, began broadcasting an HD Radio signal on 88.2 MHz last week using a BE low-powered transmission system. In the next phase of the trials, TowerCast plans to multicast two or more channels of programming.

“As a group, we???‚¬?„?re very interested in the HD Radio technology because it lets us move right into digital broadcasting without giving up analogue,” said Anders R??¤llvik, who is the technical lead for testing digital technology for TowerCast. “I believe we???‚¬?„?re the first broadcaster to use HD Radio live, 24 hours in Europe,” he added.

TowerCast, a subsidiary of NRJ Group, is the first privately held French tower company, managing several hundred elevated points for the transmission of radio broadcasts (FM, DAB), digital terrestrial television, telecommunications (UMTS, BLR), and professional radio. TowerCast is present in Finland with his subsidiary TeleMast and in Belgium with TowerCast Belgium.

SIRTI is the professional organization of 123 independent local and regional broadcasting operators. NRJ Group is a European broadcast group with four major radio networks in France and a television station.

Rapha??«l Eyraud, radio and International director of TowerCast, said, “We really appreciate the cooperation with iBiquity and BE. This first broadcast of HD Radio in Europe is a real success.” TowerCast is broadcasting HD Radio on 88.2 MHz with a test licence granted by Conseil sup??©rieur de l’audiovisuel (CSA), France???‚¬?„?s broadcast authority.

CSA has also granted TowerCast an experimental licence to broadcast HD Radio on 93.9 MHz. The group will begin broadcasting a single channel of digital audio on 93.9 MHz in the next month and will eventually add another programme channel to test HD Radio multicasting as well as any channel spacing interference

“We???‚¬?„?re more than happy to supply the equipment and the expertise we???‚¬?„?ve accumulated with similar environments in the United States, Latin America and Asia,” said Tim Bealor, BE???‚¬?„?s Vice President, RF Systems. BE sent a field service engineer to Paris from its Quincy, Ill, factory to install an FXi 250 and HD Radio signal generator into a separate antenna and to demonstrate the technology to TowerCast staff.

Initial performance measurements indicate that HD Radio is a viable and desirable option for broadcasts in France, as well as other parts of Europe even with narrow channel spacing, said Scott Stull, iBiquity???‚¬?„?s Vice President, Broadcast Business Development. “This demonstration permits a glimpse of terrestrial radio of the future, notably the better quality and greater services offered by HD Radio compared to standard analogue. We???‚¬?„?re very interested in the results as are European broadcasters who also want to take advantage of HD Radio compatibility with existing analog broadcasts,” continued Stull.

“Performance test results look very good so far,” commented R??¤llvik, who said installation went smoothly.

(Source: Ibiquity)
MR1

Re: HD radio?

Мнениеот MR1 » 09 Мар 2008, 12:41

ЖОРО написа:България тествала и отказала !! застава твърдо зад DAB

DAB подобре ли е от HD радио ?
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Re: HD radio?

Мнениеот radiator » 17 Мар 2008, 23:31

Ами... не точно.. Зависи по-точно!

А България като знам как е "тествала" - махни, махни.
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Re: HD radio?

Мнениеот 396 » 20 Мар 2008, 19:54

DAB по-скоро няза на цифрова TV, сложно омазан поток с тая квадратурно-амплитудна модулация...
HD е по-скоро като мултикаст стрийм - просто декодираш без много формалности и купчина преработка...

Но това е грубо казано!! От тия 2 предпочитам DAB.
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Re: HD radio?

Мнениеот simeon.bg » 21 Мар 2008, 01:32

HD радио няма защото high definition е за широкоекранен плазмен телевизор. Формати за телевизори използвани най-често за цифров сигнал са HDTV- цифрова телевизия изцяло дигитално висококачествено предаване, а за наземно телевизионно разпръскване (ТВ канал) е DVB-T, за наземно радиоразпръскване (УКВ) T-DAB от скоро се използва в Румъния за няколко радиостанции на честота 223 MHz, за повече информация http://www.predavatel.ro/
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Re: HD radio?

Мнениеот ogibo » 21 Мар 2008, 14:39

simeon.bg написа:HD радио няма защото high definition е за широкоекранен плазмен телевизор.

luboj написа: а самото наименувание е просто запазена марка на няква фирма избрана от тукашното СЕМ
и не означава High Definition ами Hybrid Digital

:Old

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