High frequency communication experiments between the UK and Turkey

Erol, Berin Cemil


Performance of a non-linear adaptive beamformer algorithm for signal-of-interest extraction /
Oğuz, Özkan; Tuncer, Temel Engin; Department of Electrical and Electronics Engineering (2015)
In this thesis a non-linear adaptive beamforming technique, Adaptive Projections Subgradient Method [1] (APSM) is considered. This method uses projections over convex sets in Reproducing Kernel Hilbert Space. Main advantage of this method is observed if the signal-of-interest is due to digital modulation and when there are more jammers than the number of antennas. The performance of this non-linear beamforming technique is compared with well-known methods including Minimum Variance Distortionless Response [...
A Comparison of sparse signal recovery and approximate bayesian inference methods for sparse channel estimation
Uçar, Ayla; Candan, Çağatay; Department of Electrical and Electronics Engineering (2015)
The concept of sparse representation is one of the central methodologies of modern signal processing and it has had significant impact on numerous application fields such as communications and imaging. Sparsity expresses the idea that the information rate of a continuous time signal may be much smaller than suggested by its bandwidth, or that a discrete time signal depends on a number of degrees of freedom which is comparably much smaller than its (finite) length. With recent advances in sparse signal estim...
Propagation models for hilly terrain based on ray optic methods
Yıldırım, Erkan Ersin; Dural Ünver, Mevlüde Gülbin; Department of Electrical and Electronics Engineering (2015)
In RF propagation path loss modeling, numerical methods may not be useful since they require very long computation times because electrically very large objects may be located in the terrain. Ray optic methods such as Geometrical Optics (GO) or Geometrical Theory of Diffraction (GTD) are more commonly used in propagation problems as well as the empirical models. Although ray optics methods are designed for very high frequency applications, they provide quite accurate path loss estimations in hilly terrain i...
An Investigation on belief propagation decoding of polar codes
Doğan, Orkun; Diker Yücel, Melek; Department of Electrical and Electronics Engineering (2015)
Polar codes are provably symmetric capacity achieving codes for any given binary input discrete memoryless channel, with low encoding and decoding complexities. Polar codes introduced by Erdal Arıkan in 2009 are based on the channel polarization. N binary channels are synthesized out of N copies of binary input discrete memoryless channels, such that as N goes to infinity each of the synthesized channel’s capacity goes to either 0 or 1; i.e., the channels are seen purely as noisy or noiseless channels. Thes...
A study on the set choice of multiple factor graph belief propagation decoders for polar codes
Akdoğan, Şükrü Can; Diker Yücel, Melek; Department of Electrical and Electronics Engineering (2018)
Polar codes are linear block codes with low encoding and decoding complexity that are proven to achieve the channel capacity for any given binary-input discrete memoryless channel as the codeword length {u1D441} goes to infinity. The main idea of polar codes is about channel polarization. Special factor graphs are used to represent the encoding and decoding structure of polar codes. These factor graphs consist of {u1D45B} stages for ({u1D441},{u1D43E}) codes, where {u1D45B} = {u1D459}{u1D45C}{u1D454}2{u1D44...
Citation Formats
B. C. Erol, “High frequency communication experiments between the UK and Turkey,” Ph.D. - Doctoral Program, Middle East Technical University, 1996.