Habib Senol | Kadir Has University (original) (raw)

Papers by Habib Senol

Research paper thumbnail of Subspace-Based Estimation of Rapidly Varying Mobile Channels for OFDM Systems

IEEE Transactions on Signal Processing, 2021

It is well-known that time-varying channels can provide time diversity and improve error rate per... more It is well-known that time-varying channels can provide time diversity and improve error rate performance compared to time-invariant fading channels. However, exploiting time diversity requires very accurate channel estimates at the receiver. In order to reduce the number of unknown channel coefficients while estimating the time-varying channel, basis expansion models can be used along with long transmission frames that contain multiple orthogonal frequency division multiplexing (OFDM) symbols that experience the channel variation. The design of these OFDM frames need to judiciously incorporate training and data insertions in the transmitted signal while maintaining orthogonality. In this work, we propose an inter channel interference (ICI)-free training model depending on pilot symbols only and provide a corresponding time-varying channel estimation method. This scheme relies on an algorithm to determine the number of OFDM symbols per frame and the number of basis functions per path with minimal information about the Doppler bandwidth. As a performance benchmark, Bayesian Cramér Rao lower bound (CRLB) and the corresponding MSE bound are derived analytically for the proposed training model. Theoretical MSE expressions of the proposed estimation scheme are also derived as well as the MSE expressions in the presence of Doppler frequency mismatch. Simulations exhibit substantial MSE improvement and the corresponding Symbol Error Rate (SER) performances of the low complexity estimation scheme. They also corroborate that, unlike the common results in the literature, an OFDM system can perform better as the Doppler frequency increases with judicious design of training and channel estimation schemes.

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Research paper thumbnail of Rapidly Time-Varying Channel Estimation for Full-Duplex Amplify-and-Forward One-Way Relay Networks

IEEE Transactions on Signal Processing, 2018

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Research paper thumbnail of Dik Kanallara Sahip Bir Telsiz Sens¨ or Aù gõnda Kanal Kestirim Hatasõnõn Kaynak Kestirimcisinin Basarõmõna Etkisi Effect of the Channel Estimation Error on the Performance of the Source Estimator in a Wireless Sensor Network with Orthogonal Channels

or au gonda kanal kestirim hatasonon kaynak kestirimcisinin ortalama kare- sel hata (OKH) basarom... more or au gonda kanal kestirim hatasonon kaynak kestirimcisinin ortalama kare- sel hata (OKH) basaromona etkisi incelenmistir. u safhada, s¨ on¨ umlemeli dik kanal katsayolaronon kestirildiu gi, ikinci safhada da kanal kestirim deu ve f¨ uzyon merkezine (FM) iletilen sens¨ or gdeu gerlerinin kaynak kestirimi icin kullanoldou go, iki safhalo bir yaklas ¸om kullanolmaktador. K¨¨ kanallara sahip sens¨ orlerin ikinci safhada kapalo tutulmaso gerektiu g¨ osteren, g¨ ucb ¨ ol¨ us ¸ ¨ umeniyilemesi icin kanal kestirim deu gerlerinin sens¨ orlere geri g¨ onderildiu bir sens¨ or au go ele alonmaktador. Bunun yano sora bir de eu gitme icin kullanolan toplam g¨ uc¨ un, toplam g¨ uc¨ un en azondan yaroso kadar olmaso gerektiu gi g¨ osterilmektedir. Analitik bulgularomoz benzetim sonuclaroyla dou Abstract In this work, effect of the channel estimation error on the MSE performance of the source estimator in a wireless sensor network with orthogonal flat fading channels is studied. A two-phase ap- pro...

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Research paper thumbnail of Channel Estimation for Realistic Indoor Optical Wireless Communication in ACO-OFDM Systems

Wireless Personal Communications

In this paper, channel estimation problem in a visible light communication system is considered. ... more In this paper, channel estimation problem in a visible light communication system is considered. The information data is transmitted using asymmetrical clipped optical orthogonal frequency division multiplexing. Channel estimation and symbol detection are performed by the Maximum Likelihood and the Linear Minimum Mean Square Error detection techniques, respectively. The system performance is investigated in realistic environment that is simulated using an indoor channel model. Two different channels are produced using the indoor channel model. Symbol error rate (SER) performance of the system with estimated channels is presented for QPSK and 16-QAM digital modulation types and compared with the perfect channel state information. As a mean square error (MSE) performance benchmark for the channel estimator, Cramer–Rao lower bound is also derived. MSE and SER performances of the simulation results are presented.

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Research paper thumbnail of Channel Estimation in Underwater Cooperative OFDM System with Amplify-and-Forward Relaying

Abstract—This paper is concerned with a challenging problem of channel estimation for amplify-and... more Abstract—This paper is concerned with a challenging problem of channel estimation for amplify-and-forward cooperative relay based orthogonal frequency division multiplexing (OFDM) systems in the presence of sparse underwater acoustic channels and of the correlative non-Gaussian noise. We exploit the sparse structure of the channel impulse response to improve the performance of the channel estimation algorithm, due to the reduced number of taps to be estimated. The resulting novel algorithm initially estimates ...

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Research paper thumbnail of Joint Channel Estimation, Equalization, and Data Detection for OFDM Systems in the Presence of Very High Mobility

Ieee Transactions on Signal Processing, Aug 1, 2010

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Research paper thumbnail of Outage Scaling Laws and Diversity for Distributed Estimation Over Parallel Fading Channels

Ieee Transactions on Signal Processing, Aug 1, 2009

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Research paper thumbnail of Sparse underwater acoustic channel estimation in colored gaussian noise

Cooperative underwater acoustic communication systems come into prominence in recent years. Since... more Cooperative underwater acoustic communication systems come into prominence in recent years. Since underwater channels are sparse and additive noise entering the system is colored Gaussian noise. Therefore it is very difficult to estimate the underwater channels and theoretically makes it interesting. In this study, the transmission from source to the target recipient is realized by means of a relay system. Orthogonal frequency division multiplexing (OFDM)-based channel estimation problem is solved by using the matching pursuit (MP) ...

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Research paper thumbnail of Optimal Power Allocation between Training and Data for MIMO Two-Way Relay Channels

IEEE Communications Letters, 2015

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Research paper thumbnail of Performance investigation of IEEE 802.11af systems under realistic channel conditions

2015 International Wireless Communications and Mobile Computing Conference (IWCMC), 2015

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Research paper thumbnail of Frequency selective fading channel estimation in OFDM systems using KL expansion

2005 13th European Signal Processing Conference, Sep 1, 2005

ABSTRACT This paper proposes a computationally efficient, linear minimum mean square error (MMSE)... more ABSTRACT This paper proposes a computationally efficient, linear minimum mean square error (MMSE) channel estimation algorithm based on KL series expansion for OFDM systems. Based on such expansion, no matrix inversion is required in the proposed MMSE ...

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Research paper thumbnail of MP-SAGE based channel estimation for underwater cooperative OFDM systems

2013 21st Signal Processing and Communications Applications Conference, Apr 1, 2013

ABSTRACT In this paper, an efficient channel estimation algorithm is proposed for amplify-and-for... more ABSTRACT In this paper, an efficient channel estimation algorithm is proposed for amplify-and-forward (AF) cooperative relay based orthogonal frequency division multiplexing (OFDM) system in the presence of sparse underwater acoustic channels and of the correlative non-Gaussian noise. The algorithm is based on the combinations of the matching pursuit (MP) and the space-alternating generalized expectation-maximization (SAGE) technique, to improve the estimates of the channel taps and their location as well as the Gaussian mixture noise distribution parameters in an iterative way. Computer simulations show that underwater acoustic channel is estimated very effectively and the proposed algorithm has excellent symbol error rate (SER) and channel estimation performance, as compared to the existing ones.

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Research paper thumbnail of Dik Kanallara Sahip Bir Telsiz Sens¨ or Aù gõnda Kanal Kestirim Hatasõnõn Kaynak Kestirimcisinin Basarõmõna Etkisi Effect of the Channel Estimation Error on the Performance of the Source Estimator in a Wireless Sensor Network with Orthogonal Channels

Siu, 2008

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Research paper thumbnail of Performance analysis of DCO-OFDM systems in the presence of realistic indoor visible light channels

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Research paper thumbnail of Sparse Channel Estimation and Equalization for OFDM-Based Underwater Cooperative Systems with Amplify-and-Forward Relaying

IEEE Transactions on Signal Processing, 2015

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Research paper thumbnail of Modeling of visible light channels and performance analysis of ACO-OFDM

2015 23nd Signal Processing and Communications Applications Conference (SIU), 2015

ABSTRACT

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Research paper thumbnail of Distributed Estimation with Channel Estimation Error over Orthogonal Fading Channels

2007 Conference Record of the Forty-First Asilomar Conference on Signals, Systems and Computers, 2007

ABSTRACT

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Research paper thumbnail of Scaling laws for distributed estimation over orthogonal fading channels

2009 IEEE 10th Workshop on Signal Processing Advances in Wireless Communications, 2009

Abstract We analyze the outage for distributed estimation over orthogonal fading channels as a fu... more Abstract We analyze the outage for distributed estimation over orthogonal fading channels as a function of the number of sensors, K. We consider a scenario of fixed power per-sensor with an asymptotically large number of sensors. We characterize the scaling law of the ...

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Research paper thumbnail of MP-SAGE based channel estimation for underwater cooperative OFDM systems

2013 21st Signal Processing and Communications Applications Conference (SIU), 2013

ABSTRACT In this paper, an efficient channel estimation algorithm is proposed for amplify-and-for... more ABSTRACT In this paper, an efficient channel estimation algorithm is proposed for amplify-and-forward (AF) cooperative relay based orthogonal frequency division multiplexing (OFDM) system in the presence of sparse underwater acoustic channels and of the correlative non-Gaussian noise. The algorithm is based on the combinations of the matching pursuit (MP) and the space-alternating generalized expectation-maximization (SAGE) technique, to improve the estimates of the channel taps and their location as well as the Gaussian mixture noise distribution parameters in an iterative way. Computer simulations show that underwater acoustic channel is estimated very effectively and the proposed algorithm has excellent symbol error rate (SER) and channel estimation performance, as compared to the existing ones.

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Research paper thumbnail of Sparse channel estimation for OFDM-based underwater cooperative systems with amplify-and-forward relaying

2014 IEEE International Black Sea Conference on Communications and Networking (BlackSeaCom), 2014

ABSTRACT This paper is concerned with a challenging problem of channel estimation for amplify-and... more ABSTRACT This paper is concerned with a challenging problem of channel estimation for amplify-and-forward cooperative relay based orthogonal frequency division multiplexing (OFDM) systems in the presence of sparse underwater acoustic channels and of the correlative non-Gaussian noise. We exploit the sparse structure of the channel impulse response to improve the performance of the channel estimation algorithm, due to the reduced number of taps to be estimated. The resulting novel algorithm initially estimates the overall sparse channel taps from the source to the destination as well as their locations using the matching pursuit (MP) approach. The correlated non-Gaussian effective noise is modeled as a Gaussian mixture. Based on the Gaussian mixture model, an efficient and low complexity algorithm is developed based on the combinations of the MP and the space-alternating generalized expectation-maximization (SAGE) technique, to improve the estimates of the channel taps and their location as well as the noise distribution parameters in an iterative way. The proposed SAGE algorithm is designed in such a way that, by choosing the admissible hidden data properly on which the SAGE algorithm relies, a subset of parameters is updated for analytical tractability and the remaining parameters for faster convergence Computer simulations show that underwater acoustic (UWA) channel is estimated very effectively and the proposed algorithm has excellent symbol error rate and channel estimation performance.

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Research paper thumbnail of Subspace-Based Estimation of Rapidly Varying Mobile Channels for OFDM Systems

IEEE Transactions on Signal Processing, 2021

It is well-known that time-varying channels can provide time diversity and improve error rate per... more It is well-known that time-varying channels can provide time diversity and improve error rate performance compared to time-invariant fading channels. However, exploiting time diversity requires very accurate channel estimates at the receiver. In order to reduce the number of unknown channel coefficients while estimating the time-varying channel, basis expansion models can be used along with long transmission frames that contain multiple orthogonal frequency division multiplexing (OFDM) symbols that experience the channel variation. The design of these OFDM frames need to judiciously incorporate training and data insertions in the transmitted signal while maintaining orthogonality. In this work, we propose an inter channel interference (ICI)-free training model depending on pilot symbols only and provide a corresponding time-varying channel estimation method. This scheme relies on an algorithm to determine the number of OFDM symbols per frame and the number of basis functions per path with minimal information about the Doppler bandwidth. As a performance benchmark, Bayesian Cramér Rao lower bound (CRLB) and the corresponding MSE bound are derived analytically for the proposed training model. Theoretical MSE expressions of the proposed estimation scheme are also derived as well as the MSE expressions in the presence of Doppler frequency mismatch. Simulations exhibit substantial MSE improvement and the corresponding Symbol Error Rate (SER) performances of the low complexity estimation scheme. They also corroborate that, unlike the common results in the literature, an OFDM system can perform better as the Doppler frequency increases with judicious design of training and channel estimation schemes.

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Research paper thumbnail of Rapidly Time-Varying Channel Estimation for Full-Duplex Amplify-and-Forward One-Way Relay Networks

IEEE Transactions on Signal Processing, 2018

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Research paper thumbnail of Dik Kanallara Sahip Bir Telsiz Sens¨ or Aù gõnda Kanal Kestirim Hatasõnõn Kaynak Kestirimcisinin Basarõmõna Etkisi Effect of the Channel Estimation Error on the Performance of the Source Estimator in a Wireless Sensor Network with Orthogonal Channels

or au gonda kanal kestirim hatasonon kaynak kestirimcisinin ortalama kare- sel hata (OKH) basarom... more or au gonda kanal kestirim hatasonon kaynak kestirimcisinin ortalama kare- sel hata (OKH) basaromona etkisi incelenmistir. u safhada, s¨ on¨ umlemeli dik kanal katsayolaronon kestirildiu gi, ikinci safhada da kanal kestirim deu ve f¨ uzyon merkezine (FM) iletilen sens¨ or gdeu gerlerinin kaynak kestirimi icin kullanoldou go, iki safhalo bir yaklas ¸om kullanolmaktador. K¨¨ kanallara sahip sens¨ orlerin ikinci safhada kapalo tutulmaso gerektiu g¨ osteren, g¨ ucb ¨ ol¨ us ¸ ¨ umeniyilemesi icin kanal kestirim deu gerlerinin sens¨ orlere geri g¨ onderildiu bir sens¨ or au go ele alonmaktador. Bunun yano sora bir de eu gitme icin kullanolan toplam g¨ uc¨ un, toplam g¨ uc¨ un en azondan yaroso kadar olmaso gerektiu gi g¨ osterilmektedir. Analitik bulgularomoz benzetim sonuclaroyla dou Abstract In this work, effect of the channel estimation error on the MSE performance of the source estimator in a wireless sensor network with orthogonal flat fading channels is studied. A two-phase ap- pro...

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Research paper thumbnail of Channel Estimation for Realistic Indoor Optical Wireless Communication in ACO-OFDM Systems

Wireless Personal Communications

In this paper, channel estimation problem in a visible light communication system is considered. ... more In this paper, channel estimation problem in a visible light communication system is considered. The information data is transmitted using asymmetrical clipped optical orthogonal frequency division multiplexing. Channel estimation and symbol detection are performed by the Maximum Likelihood and the Linear Minimum Mean Square Error detection techniques, respectively. The system performance is investigated in realistic environment that is simulated using an indoor channel model. Two different channels are produced using the indoor channel model. Symbol error rate (SER) performance of the system with estimated channels is presented for QPSK and 16-QAM digital modulation types and compared with the perfect channel state information. As a mean square error (MSE) performance benchmark for the channel estimator, Cramer–Rao lower bound is also derived. MSE and SER performances of the simulation results are presented.

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Research paper thumbnail of Channel Estimation in Underwater Cooperative OFDM System with Amplify-and-Forward Relaying

Abstract—This paper is concerned with a challenging problem of channel estimation for amplify-and... more Abstract—This paper is concerned with a challenging problem of channel estimation for amplify-and-forward cooperative relay based orthogonal frequency division multiplexing (OFDM) systems in the presence of sparse underwater acoustic channels and of the correlative non-Gaussian noise. We exploit the sparse structure of the channel impulse response to improve the performance of the channel estimation algorithm, due to the reduced number of taps to be estimated. The resulting novel algorithm initially estimates ...

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Research paper thumbnail of Joint Channel Estimation, Equalization, and Data Detection for OFDM Systems in the Presence of Very High Mobility

Ieee Transactions on Signal Processing, Aug 1, 2010

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Research paper thumbnail of Outage Scaling Laws and Diversity for Distributed Estimation Over Parallel Fading Channels

Ieee Transactions on Signal Processing, Aug 1, 2009

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Research paper thumbnail of Sparse underwater acoustic channel estimation in colored gaussian noise

Cooperative underwater acoustic communication systems come into prominence in recent years. Since... more Cooperative underwater acoustic communication systems come into prominence in recent years. Since underwater channels are sparse and additive noise entering the system is colored Gaussian noise. Therefore it is very difficult to estimate the underwater channels and theoretically makes it interesting. In this study, the transmission from source to the target recipient is realized by means of a relay system. Orthogonal frequency division multiplexing (OFDM)-based channel estimation problem is solved by using the matching pursuit (MP) ...

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Research paper thumbnail of Optimal Power Allocation between Training and Data for MIMO Two-Way Relay Channels

IEEE Communications Letters, 2015

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Research paper thumbnail of Performance investigation of IEEE 802.11af systems under realistic channel conditions

2015 International Wireless Communications and Mobile Computing Conference (IWCMC), 2015

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Research paper thumbnail of Frequency selective fading channel estimation in OFDM systems using KL expansion

2005 13th European Signal Processing Conference, Sep 1, 2005

ABSTRACT This paper proposes a computationally efficient, linear minimum mean square error (MMSE)... more ABSTRACT This paper proposes a computationally efficient, linear minimum mean square error (MMSE) channel estimation algorithm based on KL series expansion for OFDM systems. Based on such expansion, no matrix inversion is required in the proposed MMSE ...

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Research paper thumbnail of MP-SAGE based channel estimation for underwater cooperative OFDM systems

2013 21st Signal Processing and Communications Applications Conference, Apr 1, 2013

ABSTRACT In this paper, an efficient channel estimation algorithm is proposed for amplify-and-for... more ABSTRACT In this paper, an efficient channel estimation algorithm is proposed for amplify-and-forward (AF) cooperative relay based orthogonal frequency division multiplexing (OFDM) system in the presence of sparse underwater acoustic channels and of the correlative non-Gaussian noise. The algorithm is based on the combinations of the matching pursuit (MP) and the space-alternating generalized expectation-maximization (SAGE) technique, to improve the estimates of the channel taps and their location as well as the Gaussian mixture noise distribution parameters in an iterative way. Computer simulations show that underwater acoustic channel is estimated very effectively and the proposed algorithm has excellent symbol error rate (SER) and channel estimation performance, as compared to the existing ones.

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Research paper thumbnail of Dik Kanallara Sahip Bir Telsiz Sens¨ or Aù gõnda Kanal Kestirim Hatasõnõn Kaynak Kestirimcisinin Basarõmõna Etkisi Effect of the Channel Estimation Error on the Performance of the Source Estimator in a Wireless Sensor Network with Orthogonal Channels

Siu, 2008

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Research paper thumbnail of Performance analysis of DCO-OFDM systems in the presence of realistic indoor visible light channels

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Sparse Channel Estimation and Equalization for OFDM-Based Underwater Cooperative Systems with Amplify-and-Forward Relaying

IEEE Transactions on Signal Processing, 2015

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Research paper thumbnail of Modeling of visible light channels and performance analysis of ACO-OFDM

2015 23nd Signal Processing and Communications Applications Conference (SIU), 2015

ABSTRACT

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Research paper thumbnail of Distributed Estimation with Channel Estimation Error over Orthogonal Fading Channels

2007 Conference Record of the Forty-First Asilomar Conference on Signals, Systems and Computers, 2007

ABSTRACT

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Research paper thumbnail of Scaling laws for distributed estimation over orthogonal fading channels

2009 IEEE 10th Workshop on Signal Processing Advances in Wireless Communications, 2009

Abstract We analyze the outage for distributed estimation over orthogonal fading channels as a fu... more Abstract We analyze the outage for distributed estimation over orthogonal fading channels as a function of the number of sensors, K. We consider a scenario of fixed power per-sensor with an asymptotically large number of sensors. We characterize the scaling law of the ...

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Research paper thumbnail of MP-SAGE based channel estimation for underwater cooperative OFDM systems

2013 21st Signal Processing and Communications Applications Conference (SIU), 2013

ABSTRACT In this paper, an efficient channel estimation algorithm is proposed for amplify-and-for... more ABSTRACT In this paper, an efficient channel estimation algorithm is proposed for amplify-and-forward (AF) cooperative relay based orthogonal frequency division multiplexing (OFDM) system in the presence of sparse underwater acoustic channels and of the correlative non-Gaussian noise. The algorithm is based on the combinations of the matching pursuit (MP) and the space-alternating generalized expectation-maximization (SAGE) technique, to improve the estimates of the channel taps and their location as well as the Gaussian mixture noise distribution parameters in an iterative way. Computer simulations show that underwater acoustic channel is estimated very effectively and the proposed algorithm has excellent symbol error rate (SER) and channel estimation performance, as compared to the existing ones.

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Research paper thumbnail of Sparse channel estimation for OFDM-based underwater cooperative systems with amplify-and-forward relaying

2014 IEEE International Black Sea Conference on Communications and Networking (BlackSeaCom), 2014

ABSTRACT This paper is concerned with a challenging problem of channel estimation for amplify-and... more ABSTRACT This paper is concerned with a challenging problem of channel estimation for amplify-and-forward cooperative relay based orthogonal frequency division multiplexing (OFDM) systems in the presence of sparse underwater acoustic channels and of the correlative non-Gaussian noise. We exploit the sparse structure of the channel impulse response to improve the performance of the channel estimation algorithm, due to the reduced number of taps to be estimated. The resulting novel algorithm initially estimates the overall sparse channel taps from the source to the destination as well as their locations using the matching pursuit (MP) approach. The correlated non-Gaussian effective noise is modeled as a Gaussian mixture. Based on the Gaussian mixture model, an efficient and low complexity algorithm is developed based on the combinations of the MP and the space-alternating generalized expectation-maximization (SAGE) technique, to improve the estimates of the channel taps and their location as well as the noise distribution parameters in an iterative way. The proposed SAGE algorithm is designed in such a way that, by choosing the admissible hidden data properly on which the SAGE algorithm relies, a subset of parameters is updated for analytical tractability and the remaining parameters for faster convergence Computer simulations show that underwater acoustic (UWA) channel is estimated very effectively and the proposed algorithm has excellent symbol error rate and channel estimation performance.

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