Processors

Startup combines CD-quality audio and wireless


When it comes to audio equipment I let my aficionado friends pick the appropriate components in the hope that I may someday be able to hear the subtle nuances they talk about. Maybe not though, as I recently questioned the unwritten but absolute audiophile law decreeing that one must use those massive Monster audio cables.

So the announcement today by Avnera-a three-year-old fabless chip vendor-was especially meaningful to this "loving anything wireless" audiophile wannabe. According to this October 22, 2007 article by EETimes, Avnera claims to have developed a proprietary chipset, which uses 2.4GHz ISM wireless to provide CD quality output to the speakers.

Avnera's unique approach doesn't use any of the normal two-way data transmission protocols. Manpreet Khaira founder and CEO of Avnera explains:

 "High-fidelity audio is a one-way street: Data moves from the music player to the speakers. But Wi-Fi and Bluetooth are both designed to transmit data packets using a two-way transceiver and thus require complex network configuration settings for the twin channels. Because the data-based standards require that handshaking signals be transmitted back to the sender, their chips sets' radio section is twice as complicated as Avnera's one-way connection."

One-way connections make sense for eliminating latency and the need for memory buffering. But what happens if corrupt data is sent or interference prevents packets from arriving at the receiver? Avnera has developed some innovative technology to overcome these problems. The company has adapted the following error handling algorithms used by CD technology and extended the process to work with wireless transmissions.

Parity: Avnera adds error correction bits to each transmitted frame. The receiver having what Avnera calls a "forward error correction packet repair algorithm" is then able to determine if that particular frame is corrupt and use the additional bits to correct the frame all in real time. Interpolation: Parity is only effective with short-term interference, so to deal with larger data losses, Avnera uses an interpolation algorithm. The nature of analog music waveforms allows the algorithm to guess what's missing by sampling the preceding and following frames. Interpolation is where my audiophile friends get excited. You need to have a stellar algorithm otherwise the digital interpretation is not an accurate representation.

Since the popular 2.4GHz ISM frequency range is being used, Avnera developed a proprietary radio using 40 channels that are only 2MHz wide as a means to contend with overcrowding. The small channel bandwidth allows the transmitter to avoid interference by sensing active Wi-Fi signals and using alternate channels.

According to the article, the chip set is already in equipment being sold by several companies, like Best Buy. Their Rocketfish rear speaker kit lets you add surround sound without having to run the normal audio cables.

Now that's what I'm talking about!

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Information is my field...Writing is my passion...Coupling the two is my mission.

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