Electrical - Electronic Engineering / Elektrik - Elektronik Mühendisliği
Permanent URI for this collectionhttps://hdl.handle.net/11147/11
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Conference Object Citation - Scopus: 1Avrupa Karasal Sayısal Televizyon Standartlarının Tbgg Kanalı Etkisindeki Performans Karşılaştırması(IEEE, 2012) Karakuş, Oktay; Özen, SerdarIn this study, a general simulation of the European Digital Terrestrial Television Broadcasting standards which are known as "Digital Video Broadcasting - Terrestrial (DVB-T)" and "Second Generation Digital Video Broadcasting - Terrestrial (DVB-T2)" are implemented. The both of the standards are simulated under the effects of Additive White Gaussian Noise (AWGN) Channel and the acquired results are compared according to the Target Bit Error Rate (BER) value which is stated in standards. These results show that DVB-T2 standard outperforms DVB-T standard under AWGN Channel and achieves nearly from four to seven decibels power gain according to code rate and modulation parameters. © 2012 IEEE.Conference Object Kentsel Alanlarda Gölgeleme Etki̇sinin Benzetim ve Anali̇zi̇(Institute of Electrical and Electronics Engineers Inc., 2011) Sancaklı, Sibel; Özen, SerdarA low complexity correlation model for the received signal in shadowing in a mobile radio system was proposed. The predicted autocorrelation function is obtained via a site-specific radio propagation tool which uses ray tracing. L2-norm method is used to fit the proposed model to the experimental results and the model parameters of this method is acquired via numerical optimization. The predicted results are compared with the other models in the literature and we report that our model has lower computational complexity and more suitable for hardware emulator implementations than existing models. © 2011 IEEE.Conference Object Citation - Scopus: 1Fpga Implementation of a Low-Complexity Fading Filter for Multipath Rayleigh Fading Simulator(Institute of Electrical and Electronics Engineers Inc., 2011) Toker, Kadir Atilla; Özen, Serdar; Arsal, AliA low-complexity high performance Rayleigh fading simulator and its Field Programmable Gate Array (FPGA) implementation are presented. This proposed method is a variant of the method of filtering of the white Gaussian noise where the filter design is accomplished in the analog domain and transferred into digital domain. The proposed method outperforms AR(20) filter and modified Jakes' generators in performance. Although IDFT method achieves the best performance, it brings a significant cost in storage. The proposed method achieves high performance with the lowest complexity, and its performance has been verified on commercially available FPGA platforms. © 2011 IEEE.Article Taylor Series Approximation of Semi-Blind Blue Channel Estimates With Applications To Dtv(Taylor and Francis Ltd., 2008) Pladdy, Christopher; Özen, Serdar; Nerayanuru, Sreenivasa M.; Ding, Peilu; Fimoff, Mark J.; Zoltowski, MichaelWe present a low-complexity method for approximating the semi-blind best linear unbiased estimate (BLUE) of a channel impulse response (CIR) vector for a communication system, which utilizes a periodically transmitted training sequence. The BLUE, for h, for the general linear model, y = Ah + w + n, where w is correlated noise (dependent on the CIR, h) and the vector n is an Additive White Gaussian Noise (AWGN) process, which is uncorrelated with w is given by h = (ATC(h)-1A)-1ATC(h)-1y. In the present work, we propose a Taylor series approximation for the function F(h) = (ATC(h)-1A)-1ATC(h)-1y. We describe the full Taylor formula for this function and describe algorithms using, first-, second-, and third-order approximations, respectively. The algorithms give better performance than correlation channel estimates and previous approximations used, at only a slight increase in complexity. Our algorithm is derived and works within the framework imposed by the ATSC 8-VSB DTV transmission system, but will generalize to any communication system utilizing a training sequence embedded within data.Conference Object Citation - Scopus: 5A Fading Filter Design for Multipath Rayleigh Fading Simulation and Comparisons To Other Simulators(Institute of Electrical and Electronics Engineers Inc., 2008) Arsal, Ali; Özen, SerdarA low-complexity high performance Rayleigh fading simulator, an ARMA(3,3) model, is proposed. This proposed method is a variant of the method of filtering of the white Gaussian noise where the filter design is accomplished in the analog domain and transferred into digital domain. The proposed model is compared with improved Jakes' model, autoregressive filtering and IDFT techniques, in performance and computational complexity. Proposed method outperforms AR(20) filter and modified Jakes' generators in performance. Although IDFT method achieves the best performance, it brings a significant cost in storage and is undesirable. The proposed method achieves high performance with the lowest complexity.Conference Object Citation - Scopus: 1Approximate Best Linear Unbiased Channel Estimation With Cfar Detection for Frequency Selective Sparse Multipath Channels With Long Delay Spreads(Institute of Electrical and Electronics Engineers Inc., 2005) Özen, SerdarWe provide a non-iterative channel impulse response (CIR) estimation algorithm for communication systems which utilize a periodically transmitted training sequence within a continuous stream of information symbols. The non-iterative channel estimate is an approximation to the Best Linear Unbiased Estimate (BLUE) of the CIR, achieving almost similar performance, with much lower complexity. We first provide a formulation of the received data and correlation processing with the adjacent symbol correlation taken into account, and we then present the connections of the correlation based CIR estimation scheme to the ordinary least squares CIR estimation, and the approximate BLUE CIR estimation. Simulation results are provided to demonstrate the performance of the novel algorithms for 8-VSB ATSC Digital TV system.Conference Object Citation - WoS: 2Citation - Scopus: 2Taylor Series Approximation of Semi-Blind Best Linear Unbiased Channel Estimates for the General Linear Model(Institute of Electrical and Electronics Engineers Inc., 2004) Pladdy, Christopher; Nerayanuru, Sreenivasa M.; Fimoff, Mark; Özen, Serdar; Zoltowski, MichaelWe present a low complexity approximate method for semi-blind best linear unbiased estimation (BLUE) of a channel impulse response vector (CIR) for a communication system, which utilizes a periodically transmitted training sequence, within a continuous stream of information symbols. The algorithm achieves slightly degraded results at a much lower complexity than directly computing the BLUE CIR estimate. In addition, the inverse matrix required to invert the weighted normal equations to solve the general least squares problem may be pre-computed and stored at the receiver. The BLUE estimate is obtained by solving the general linear model, y = Ah + w + n, for h, where w is correlated noise and the vector n is an AWGN process, which is uncorrelated with w. The Gauss - Markoff theorem gives the solution h = (A TC(h) -1A) -1A TC(h) -1y. In the present work we propose a Taylor series approximation for the function F(h) = (A TC(h) -1A) -1A TC(h) -1y where, F:R L → R L for each fixed vector of received symbols, y, and each fixed convolution matrix of known transmitted training symbols, A. We describe the full Taylor formula for this function, F(h) = F(h id) + ∑|α|≥|(h - h id) α(∂/∂h) αF(h id) and describe algorithms using, respectively, first, second and third order approximations. The algorithms give better performance than correlation channel estimates and previous approximations used, [15], at only a slight increase in complexity. The linearization procedure used is similar to that used in the linearization to obtain the extended Kaiman filter, and the higher order approximations are similar to those used in obtaining higher order Kaiman filter approximations,