tailieunhanh - Báo cáo hóa học: " Research Article Distortion-Based Link Adaptation for Wireless Video Transmission"

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 Distortion-Based Link Adaptation for Wireless Video Transmission | Hindawi Publishing Corporation EURASIP Journal on Advances in Signal Processing Volume 2008 Article ID 253706 17 pages doi 2008 253706 Research Article Distortion-Based Link Adaptation for Wireless Video Transmission Pierre Ferre 1 James Chung-How 2 David Bull 1 and Andrew Nix1 1 Centre for Communications Research University of Bristol Woodland Road Bristol BS8 1UB UK 2 ProVision Communication Technologies Limited 3 Chapel Way St. Anne s Bristol BS4 4EU UK Correspondence should be addressed to Pierre Ferris Received 15 October 2007 Accepted 10 March 2008 Recommended by F. Babich Wireless local area networks WLANs such as IEEE g utilise numerous transmission modes each providing different throughputs and reliability levels. Most link adaptation algorithms proposed in the literature i maximise the error-free data throughput ii do not take into account the content of the data stream and iii rely strongly on the use of ARQ. Low-latency applications such as real-time video transmission do not permit large numbers of retransmission. In this paper a novel link adaptation scheme is presented that improves the quality of service QoS for video transmission. Rather than maximising the error-free throughput our scheme minimises the video distortion of the received sequence. With the use of simple and local rate distortion measures and end-to-end distortion models at the video encoder the proposed scheme estimates the received video distortion at the current transmission rate as well as on the adjacent lower and higher rates. This allows the system to select the link-speed which offers the lowest distortion and to adapt to the channel conditions. Simulation results are presented using the MPEG-4 AVC video compression standard over IEEE . The results show that the proposed system closely follows the optimum theoretic solution. Copyright 2008 Pierre Ferre et al. This is an open access article distributed under the Creative .