DocumentCode :
1416141
Title :
Turbo- and BCH-coded wide-band burst-by-burst adaptive H.263-assisted wireless video telephony
Author :
Cherriman, Peter ; Wong, Choong Hin ; Hanzo, Lajos
Author_Institution :
Dept. of Electron. & Comput. Sci., Southampton Univ., UK
Volume :
10
Issue :
8
fYear :
2000
fDate :
12/1/2000 12:00:00 AM
Firstpage :
1355
Lastpage :
1363
Abstract :
The video performance benefits of burst-by-burst adaptive modulation are studied, employing a higher-order modulation scheme when the channel is favorable, in order to increase the system´s bits per symbol capacity and conversely, invoking a more robust lower order modulation scheme when the channel exhibits inferior channel quality. It is shown that due to the proposed adaptive modem mode switching regime, a seamless video quality versus channel quality relationship can be established, resulting in error-free video quality right actress the operating channel signal-to-noise ratio (SNR) range. The main advantage of the proposed burst-by-burst adaptive transceiver technique is that irrespective of the prevailing channel conditions, the transceiver achieves always the best possible source-signal representation quality-such as video, speech, or audio quality-by automatically adjusting the achievable bit rate and the associated multimedia source-signal representation quality in order to match the channel quality experienced. This is achieved on a near-instantaneous basis under given propagation conditions in order to cater for the effects of path loss, fast-fading, slow-fading, dispersion, co-channel interference, etc. Furthermore, when the mobile is roaming in a hostile out-doors-or even hilly terrain-propagation environment, typically low-order low-rate modem modes are invoked, while in benign indoor environments, predominantly the high-rate high source-signal representation quality modes are employed
Keywords :
BCH codes; adaptive modulation; channel capacity; code standards; land mobile radio; modems; signal representation; transceivers; turbo codes; video coding; videotelephony; BCH codes; SNR; adaptive H.263-assisted wireless video telephony; adaptive modem mode switching; adaptive modulation; adaptive transceiver; audio quality; bits per symbol capacity; channel quality; channel signal-to-noise ratio; co-channel interference; dispersion; error-free video quality; fast-fading; high source-signal representation quality; higher-order modulation; indoor environments; low-order low-rate modem modes; lower order modulation; mobile radio; multimedia source-signal representation quality; path loss; propagation conditions; propagation environment; slow-fading; source-signal representation quality; speech quality; turbo codes; video performance; wide-band burst-by-burst video telephony; Bit rate; Dispersion; Interchannel interference; Modems; Propagation losses; Robustness; Signal to noise ratio; Speech; Transceivers; Wideband;
fLanguage :
English
Journal_Title :
Circuits and Systems for Video Technology, IEEE Transactions on
Publisher :
ieee
ISSN :
1051-8215
Type :
jour
DOI :
10.1109/76.889019
Filename :
889019
Link To Document :
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