Joint Channel Estimation And Decoding For Wireless Channels

Treats joint source and channel decoding in an integrated way Gives a clear description of the problems in the field together with the mathematical tools for their solution Contains many detailed examples useful for practical applications of the theory to video broadcasting over mobile and wireless networks Traditionally, cross-layer and joint source-channel coding were seen as incompatible with classically structured networks but recent advances in theory changed this situation. Joint source-channel decoding is now seen as a viable alternative to separate decoding of source and channel codes, if the protocol layers are taken into account. A joint source/protocol/channel approach is thus addressed in this book: all levels of the protocol stack are considered, showing how the information in each layer influences the others. This book provides the tools to show how cross-layer and joint source-channel coding and decoding are now compatible with present-day mobile and wireless networks, with a particular application to the key area of video transmission to mobiles. Typical applications are broadcasting, or point-to-point delivery of multimedia contents, which are very timely in the context of the current development of mobile services such as audio (MPEG4 AAC) or video (H263, H264) transmission using recent wireless transmission standards (DVH-H, DVB-SH, WiMAX, LTE). This cross-disciplinary book is ideal for graduate students, researchers, and more generally professionals working either in signal processing for communications or in networking applications, interested in reliable multimedia transmission. This book is also of interest to people involved in cross-layer optimization of mobile networks. Its content may provide them with other points of view on their optimization problem, enlarging the set of tools which they could use. Pierre Duhamel is director of research at CNRS/ LSS and has previously held research positions at Thomson-CSF, CNET, and ENST, where he was head of the Signal and Image Processing Department. He has served as chairman of the DSP committee and associate Editor of the IEEE Transactions on Signal Processing and Signal Processing Letters, as well as acting as a co-chair at MMSP and ICASSP conferences. He was awarded the Grand Prix France Telecom by the French Science Academy in 2000. He is co-author of more than 80 papers in international journals, 250 conference proceedings, and 28 patents. Michel Kieffer is an assistant professor in signal processing for communications at the Université Paris-Sud and a researcher at the Laboratoire des Signaux et Systèmes, Gif-sur-Yvette, France. His research interests are in joint source-channel coding and decoding techniques for the reliable transmission of multimedia contents. He serves as associate editor of Signal Processing (Elsevier). He is co-author of more than 90 contributions to journals, conference proceedings, and book chapters. Treats joint source and channel decoding in an integrated way Gives a clear description of the problems in the field together with the mathematical tools for their solution Contains many detailed examples useful for practical applications of the theory to video broadcasting over mobile and wireless networks

Finally, for vertical Bell Laboratories layered space-time OFDM systems, we propose an iterative channel estimator based on a PSAM structure for time-varying multipath fading channels. By exploiting the statistical properties of a wireless channel, we also develop a method to suppress intercarrier interference due to the channel time selectivity, and propose a low-complexity iterative channel estimator that exploits a priori information in an efficient manner.

"In this thesis, we study and develop joint synchronization, channel estimation and decoding schemes to provide high system performance at a relatively low complexity for uncoded and coded OFDM systems." --

Eine vielversprechende Technologie zur Maximierung der Bandbreiteneffizienz in der breitbandigen drahtlosen Kommunikation ist die Raum-Zeit-Kodierung. Theorie und Praxis verbindend, ist dieses Buch die erste umfassende Diskussion von Grundlagen und designorientierten Aspekten von Raum-Zeit-Codes. Single-Carrier und Multi-Carrier-Übertragungen für Einzel- und Mehrnutzerkommunikation werden behandelt.

In wireless communications, the wireless channels may exhibit frequency-selectivity and time-variability, and channel coefficients may have large and small scale fadings. All of these effects, together with thermal noise, severely impair the received signals. The receivers are thus designed to undo these effects to recover the transmitted signals. In practice, receivers usually utilize channel state information (CSI) that is obtained through training-based channel estimation. In the presence of channel noise, CSI can hardly be estimated perfectly. In multi-user scenario, what is even worse is that one user may be interfered by other users, thus causing the estimated CSI of one user being contaminated by that of other users. Furthermore, pilots are sometimes inadequate or unavailable, and therefore only partial CSI is known at receiver. This dissertation is focused on designing robust receivers for a number of non-ideal scenarios. For most receivers, detection and decoding are separated as two sequential steps, that is, output of the detector is fed to a downstream decoder. The major obstacle of combining the two steps lies in the fact that detection is performed on real or complex field, whereas decoding is usually on finite field. In the recent decade, a new decoding scheme in the form of linear programming (LP) gains wide popularity since the seminal work by Feldman. The LP decoding opens the door for a new era of receiver design that integrates detection and decoding stages. Unlike the quasi-joint turbo receiver exchanging extrinsic information iteratively between detector and decoder, we propose receiver formulations that jointly detect and decode received signals in use of LP decoding constraints. We name the proposed design paradigm the code anchored robust design (CARD). The effectiveness of CARD receivers is demonstrated by numerical results that establish substantial performance gain of the proposed receivers over existing designs. In addition, the designed joint receivers can be extended for turbo processing, and can also be used in distributed multi-cell processing for improved performance.