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: Characterization of a Class of Error Correcting Frames for Robust Signal Transmission over Wireless Communication Channels | EURASIP Journal on Applied Signal Processing 2005 2 229-241 2005 Hindawi Publishing Corporation Characterization of a Class of Error Correcting Frames for Robust Signal Transmission over Wireless Communication Channels Gagan Rath IRISA INRIA Campus de Beaulieu 35042 Rennes France Email Christine Guillemot IRISA INRIA Campus de Beaulieu 35042 Rennes France Email Received 14 July 2003 Revised 24 May 2004 Joint source-channel coding has been introduced recently as an element of QoS support for IP-based wired and wireless multimedia. Indeed QoS provisioning in a global mobility context with highly varying channel characteristics is all the most challenging and requires a loosening of the layer and source-channel separation principle. Overcomplete frame expansions have been introduced as joint source-channel codes for erasure channels that is to allow for a signal representation that would be resilient to erasures in wired and wireless channels. In this paper we characterize a class of frames for error correction besides erasure recovery in such channels. We associate the frames with complex number codes and characterize them based on the BCH-like property of the parity check matrices of the associated codes. We show that in addition to the BCH-type decoding subspace-based algorithms can also be used to localize errors over such frame expansion coefficients. When the frame expansion coefficients are quantized we modify these algorithms suitably and compare their performances in terms of the accuracy of error localization and the signal-to-noise ratio of the reconstructed signal. In particular we compare the frames associated with lowpass DFT DCT and DST codes which belong to the defined class in terms of their error correction efficiency. Keywords and phrases frame theory error correction compression block transforms wireless communication. 1. INTRODUCTION The development of Beyond 3G B3G or 4G networks and applications .
