Error Control Strategies for wireless Videotelephony in a CDMA based UMTS Environment
| Author: | R. Mann Pelz |
| Abstract: | The deployment of enhanced or feature mobile telecommunnications systems can be stimulated by providing multimedia services with a broad range of data rates and different quality such as video telephony, information retrieval and audio/video broadcasting. Due to the limited spectrum resources available and an underlying hostile mobile environment advanced source processing techniques such as source coding, channel coding and modulation must be developed and applied for robust and flexible service provision. Although communication theory propagates an individual design of the addressed transmission methods as the optimal approach, combined strategies under application of a-priori information (e.g. source error sensitivity) and reliability information (e.g. soft decision decoding) are more realistic from the implementation point-of-view. This contribution presents a compound strategy for error control in the case of low data rate video services for feature Universal Mobile Telecommunications Systems (UMTS). As a potential UMTS environment we consider the DS-CDMA based mobile system proposed by Qualcomm which represents the bases of the IS-95 standard. The conducted system optimization addresses key aspects such as the choice of source accuracy, redundancy and spreading factor, and the generation of reliabilty information after the demodulation process for maximum likelihood soft decision channel decoding of convolutional codes. |
| Document type: | Conference Paper |
| Publication: | 1. September 1997 |
| Index: | 28 |
| Files: | BibTEX |
Last change on
01.03.2008
by
P. Kemkes
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