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Robust Coding Algorithm for HV1-Type Voice Packets in Bluetooth

IP.com Disclosure Number: IPCOM000131853D
Publication Date: 2005-Nov-21
Document File: 1 page(s) / 9K

Publishing Venue

The IP.com Prior Art Database

Abstract

Since the Bluetooth (BT) standard was developed mainly for the context of a "closed environment," the introduction of new standards such as IEEE 802.11 (Wi-Fi) in corporate buildings and restaurants are prone to introduce additional channel interference into the BT system. Although version 1.2 of the BT standard employs a frequency-hop transceiver to combat interference and fading, improving the coding algorithm on the base band would allow a BT system to combat bit errors much more efficiently.

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HV1 ENCODING IN BLUETOOTH

Robust Coding Algorithm for HV1-Type Voice Packets in Bluetooth

Disclosed Anonymously

Since the Bluetooth (BT) standard was developed mainly for the context of a "closed environment," the introduction of new standards such as IEEE 802.11 (Wi-Fi) in corporate buildings and restaurants are prone to introduce additional channel interference into the BT system. Although version 1.2 of the BT standard employs a frequency-hop transceiver to combat interference and fading, improving the coding algorithm on the base band would allow a BT system to combat bit errors much more efficiently.

Even for the highest coding type (HV1), the current version of the standard uses a simple 3-times repetition for FEC (v1.2 Base band specification section 7.4). 

For example,

If the input stream is: 1 0 1 1 0 1

Then the corresponding output stream is: 111 000 111 111 000 111

 

This is not robust enough to combat the bit errors involved in a channel in which BT co-exists with other devices using the same 2.4 GHz unlicensed band (such as WiFi).  For instance, in the event of continuous bit errors, the probability of the receiver determining the original data is very low. 

Thus, a better forward error-correction (FEC) scheme must be introduced, such as 1/3 convolutional encoding (and Viterbi decoding) with a defined set of polynomials and, possibly, an efficient interleaving algorithm.  The simplest way to approach this problem is to use a polynomial structure, such as th...