A study of precoding schemes for ofdm systems

Download

index.pdf

Date

2008

Author

Çakar, F. Selcen

Metadata

Show full item record

Item Usage Stats

137
views

40
downloads

We examine the effect of precoding on OFDM systems. The precoding operation, which is also known as constellation rotation, leads to a gain in diversity order for fading channels. In this thesis, we examine the effect of precoding for different receivers such as Maximum Likelihood (ML), Minimum Mean Squared Error (MMSE), and Zero Forcing (ZF) receivers. The diversity gain due to precoding comes at no cost of bandwidth expansion or power increase. Therefore it is an attractive and practical alternative. We also examine the precoding gain, when some reduction of rate is tolerable and compare the performance of rate reduced system with the uncoded system with the system which is coded by rateless unitary precoders, and with the hard-decision decoded BCH coded coded system.

Subject Keywords

Electrical engineering., Diversity., Optimal Control.

URI

http://etd.lib.metu.edu.tr/upload/12609916/index.pdf
https://hdl.handle.net/11511/17984

Collections

Graduate School of Natural and Applied Sciences, Thesis

Suggestions

OpenMETU
Core

A Structuralist Defence of the Integrated Information Theory of Consciousness Davoody Benı, Majıd (2018-09-01) This paper addresses John Searle's criticism of the integrated information theory of consciousness (IITC for short). Among other things, Searle claimed that, since information is a syntactic notion, IITC cannot account for the content of consciousness. He also argued that IITC cannot explain consciousness in causal terms. In this paper, I demonstrate that the original formulation of IITC is compatible with a structuralist reading. After that, I explain how a structuralist reconstruction of IITC could deal w...
A survey on OR and mathematical methods applied on gene-environment networks Weber, Gerhard Wilhelm; Kropat, Erik; Öztürk, Başak; Gorgulu, Zafer-Korcan (Springer Science and Business Media LLC, 2009-09-01) In this paper, we survey the recent advances and mathematical foundations of gene-environment networks. We explain their interdisciplinary implications with special regard to human and life sciences as well as financial sciences. Special attention is paid to applications in Operational Research and environmental protection. Originally developed in the context of modeling and prediction of gene-expression patterns, gene-environment networks have proved to provide a conceptual framework for the modeling of dy...
Parameter extraction and image enhancement for catadioptric omnidirectional cameras Baştanlar, Yalın; Çetin, Yasemin; Department of Information Systems (2005) In this thesis, catadioptric omnidirectional imaging systems are analyzed in detail. Omnidirectional image (ODI) formation characteristics of different camera-mirror configurations are examined and geometrical relations for panoramic and perspective image generation with common mirror types are summarized. A method is developed to determine the unknown parameters of a hyperboloidal-mirrored system using the world coordinates of a set of points and their corresponding image points on the ODI. A linear relati...
An Optimal Transport Perspective on Gamma Gaussian Inverse-Wishart Mixture Reduction D'Ortenzio, Alessandro; Manes, Costanzo; Orguner, Umut (2022-01-01) Recent advances in the Optimal Transport theory allow to rewrite several known problems in a neat way, while providing a more general perspective. When dealing with mixture densities, or in general with intensities, such a framework naturally induces composite dissimilarities, together with corresponding Greedy Reduction and Refinement algorithms. In applications like target tracking in clutter, it is common to deal with the Mixture Reduction problem, since the optimal Bayesian recursion leads to a combinat...
An online sequential algorithm for the estimation of transition probabilities forjump Markov linear systems Orguner, Umut (Elsevier BV, 2006-10-01) This paper describes a new method to estimate the transition probabilities associated with a jump Markov linear system. The new algorithm uses stochastic approximation type recursions to minimize the Kullback-Leibler divergence between the likelihood function of the transition probabilities and the true likelihood function. Since the calculation of the likelihood function of the transition probabilities is impossible, an incomplete data paradigm, which has been previously applied to a similar problem for hi...

Citation Formats

F. S. Çakar, “A study of precoding schemes for ofdm systems,” M.S. - Master of Science, Middle East Technical University, 2008.