Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Research Article Feedback Channel Suppression in Distributed Video Coding with Adaptive Rate Allocation and Quantization for Multiuser Applications | Hindawi Publishing Corporation EURASIP Journal on Wireless Communications and Networking Volume 2008 Article ID 427247 13 pages doi 2008 427247 Research Article Feedback Channel Suppression in Distributed Video Coding with Adaptive Rate Allocation and Quantization for Multiuser Applications Charles Yaacoub 1 2 Joumana Farah 1 and Beatrice Pesquet-Popescu2 1 Department of Engineering Faculty of Sciences and Computer Engineering Holy-Spirit University ofKaslik . Box 446 Jounieh Lebanon 2 Signal and Image Processing Department TELECOM ParisTech 46 Rue Barrault 75634 Paris Cedex 13 France Correspondence should be addressed to Charles Yaacoub charlesyaacoub@ Received 8 January 2008 Accepted 18 September 2008 Recommended by Kameswara Namuduri We present a novel rate allocation technique for distributed multiuser video coding systems without the need for a permanent feedback channel. Based on analytical calculations the system unequally distributes the available bandwidth among the different users taking into account the actual amount of movement in the transmitted video as well as the transmission conditions of each user. On one hand the quantization parameters are dynamically tuned in order to optimize the decoding quality. On the other hand a frame dropping mechanism allows the system to avoid unnecessary channel use when the analytical estimations show that the successful decoding of a given frame is not possible because of very high motion or bad channel conditions. A significant gain in the system performance is noticed compared with the case of equal allocation of channel resources and constant quantization parameters. Copyright 2008 Charles Yaacoub et al. This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited. 1. INTRODUCTION During the last decade distributed source coding has made a .
