The Experts below are selected from a list of 193266 Experts worldwide ranked by ideXlab platform
Mark Shtaif - One of the best experts on this subject based on the ideXlab platform.
-
iterative symbol recovery for power efficient dc biased optical ofdm systems
Journal of Lightwave Technology, 2016Co-Authors: Amir Weiss, Arie Yeredor, Mark ShtaifAbstract:Orthogonal frequency division multiplexing (OFDM) has proven itself as an effective multicarrier digital Communication Technique. In recent years, the interest in optical OFDM has grown significantly, due to its spectral efficiency and inherent resilience to frequency-selective channels and to narrowband interference. For these reasons, it is currently considered to be one of the leading candidates for deployment in short fiber links such as the ones intended for inter-data-center Communications. In this paper, we present a new power-efficient symbol recovery scheme for dc-biased optical OFDM (DCO-OFDM) in an intensity-modulation direct-detection (IM/DD) system. We introduce an alternative method for clipping in order to maintain a nonnegative real-valued signal and still preserve information, which is lost when using clipping, and propose an iterative detection algorithm for this method. A reduction of $\text{50\%}$ in the transmitted optical power along with an increase of signal-independent noise immunity (gaining 3 dB in SNR), compared to traditional DCO-OFDM with a dc bias of $\text{two}$ standard deviations of the OFDM signal, is attained by our new scheme for a symbol error rate of $10^{-3}$ in a QPSK constellation additive white Gaussian noise flat channel model.
Amir Weiss - One of the best experts on this subject based on the ideXlab platform.
-
iterative symbol recovery for power efficient dc biased optical ofdm systems
Journal of Lightwave Technology, 2016Co-Authors: Amir Weiss, Arie Yeredor, Mark ShtaifAbstract:Orthogonal frequency division multiplexing (OFDM) has proven itself as an effective multicarrier digital Communication Technique. In recent years, the interest in optical OFDM has grown significantly, due to its spectral efficiency and inherent resilience to frequency-selective channels and to narrowband interference. For these reasons, it is currently considered to be one of the leading candidates for deployment in short fiber links such as the ones intended for inter-data-center Communications. In this paper, we present a new power-efficient symbol recovery scheme for dc-biased optical OFDM (DCO-OFDM) in an intensity-modulation direct-detection (IM/DD) system. We introduce an alternative method for clipping in order to maintain a nonnegative real-valued signal and still preserve information, which is lost when using clipping, and propose an iterative detection algorithm for this method. A reduction of $\text{50\%}$ in the transmitted optical power along with an increase of signal-independent noise immunity (gaining 3 dB in SNR), compared to traditional DCO-OFDM with a dc bias of $\text{two}$ standard deviations of the OFDM signal, is attained by our new scheme for a symbol error rate of $10^{-3}$ in a QPSK constellation additive white Gaussian noise flat channel model.
Mohamedslim Alouini - One of the best experts on this subject based on the ideXlab platform.
-
optimal power allocation for relayed transmissions over rayleigh fading channels
IEEE Transactions on Wireless Communications, 2004Co-Authors: Mazen O Hasna, Mohamedslim AlouiniAbstract:Relayed transmission is a way to attain broader coverage by splitting the Communication link from the source to the destination into several shorter links/hops. One of the main advantages of this Communication Technique is that it distributes the use of power throughout the hops. This implies longer battery life and lower interference introduced to the rest of the network. In this context, this paper investigates the optimal allocation of power over these links/hops for a given power budget. All hops are assumed to be subject to independent Rayleigh fading. Outage probability which is the probability that the link quality from source to destination falls below a certain threshold is used as the optimization criterion. Numerical results show that optimizing the allocation of power enhances the system performance, especially if the links are highly unbalanced in terms of their average fading power or if the number of hops is large. Interestingly, they also show that nonregenerative systems with optimum power allocation can outperform regenerative systems with no power optimization.
-
optimal power allocation for relayed transmissions over rayleigh fading channels
Vehicular Technology Conference, 2003Co-Authors: Mazen O Hasna, Mohamedslim AlouiniAbstract:Relayed transmission is a way to attain broader coverage by splitting the Communication link from the source to the destination into several links/hops. One of the main advantages of this Communication Technique is that it distributes the use of power throughout the hops which means longer battery lives and lower interference introduced to the rest of the network. In this context, this paper investigates the optimal allocation of power over these links/hops for a given power budget. All hops are assumed to be subject to independent Rayleigh fading. The optimization criterion used is outage probability which is the probability that the link quality from source to destination falls below a certain threshold. Numerical results show that optimizing the allocation of power enhances the system performance, specially if the links are highly unbalanced in terms of their average fading power. They also show that non-regenerative systems with optimum power allocation can outperform regenerative systems with no power optimization.
Gongpu Wang - One of the best experts on this subject based on the ideXlab platform.
-
semi coherent detection and performance analysis for ambient backscatter system
IEEE Transactions on Communications, 2017Co-Authors: Jing Qian, Feifei Gao, Gongpu Wang, Shi Jin, Hongbo ZhuAbstract:We study a novel Communication Technique, ambient backscatter, that utilizes radio frequency signals transmitted from an ambient source as both energy supply and information carrier to enable Communications between low-power devices. Different from existing noncoherent schemes, we here design the semi-coherent detection, where channel-related parameters can be obtained from unknown data symbols and a few pilot symbols. In order to obtain a benchmark for overall detection, we first derive a maximum likelihood detector assuming a complex Gaussian ambient source, and the closed-form bit error rate (BER) is computed. To release the dependence on prior knowledge of the ambient source, we next derive a type of robust design, called an energy detector, with the ambient signal being either complex Gaussian or phase shift keying (PSK). The closed-form detection thresholds, analytical BERs, and outage probability are provided correspondingly. Interestingly, the complex Gaussian source would cause an error floor, while the PSK source does not, which brings nontrivial indication of constellation design as opposed to popular Gaussian-embedded literatures. We also propose an effective approach to estimate detection-required parameters rather than channels themselves. Numerical simulations are finally presented to verify theoretical results.
-
semi coherent detection and performance analysis for ambient backscatter system
IEEE Transactions on Communications, 2017Co-Authors: Jing Qian, Gongpu WangAbstract:We study a novel Communication Technique, ambient backscatter, that utilizes radio frequency signals transmitted from an ambient source as both energy supply and information carrier to enable Communications between low-power devices. Different from existing noncoherent schemes, we here design the semi-coherent detection, where channel-related parameters can be obtained from unknown data symbols and a few pilot symbols. In order to obtain a benchmark for overall detection, we first derive a maximum likelihood detector assuming a complex Gaussian ambient source, and the closed-form bit error rate (BER) is computed. To release the dependence on prior knowledge of the ambient source, we next derive a type of robust design, called an energy detector, with the ambient signal being either complex Gaussian or phase shift keying (PSK). The closed-form detection thresholds, analytical BERs, and outage probability are provided correspondingly. Interestingly, the complex Gaussian source would cause an error floor, while the PSK source does not, which brings nontrivial indication of constellation design as opposed to popular Gaussian-embedded literatures. We also propose an effective approach to estimate detection-required parameters rather than channels themselves. Numerical simulations are finally presented to verify theoretical results.
Jing Qian - One of the best experts on this subject based on the ideXlab platform.
-
semi coherent detection and performance analysis for ambient backscatter system
IEEE Transactions on Communications, 2017Co-Authors: Jing Qian, Feifei Gao, Gongpu Wang, Shi Jin, Hongbo ZhuAbstract:We study a novel Communication Technique, ambient backscatter, that utilizes radio frequency signals transmitted from an ambient source as both energy supply and information carrier to enable Communications between low-power devices. Different from existing noncoherent schemes, we here design the semi-coherent detection, where channel-related parameters can be obtained from unknown data symbols and a few pilot symbols. In order to obtain a benchmark for overall detection, we first derive a maximum likelihood detector assuming a complex Gaussian ambient source, and the closed-form bit error rate (BER) is computed. To release the dependence on prior knowledge of the ambient source, we next derive a type of robust design, called an energy detector, with the ambient signal being either complex Gaussian or phase shift keying (PSK). The closed-form detection thresholds, analytical BERs, and outage probability are provided correspondingly. Interestingly, the complex Gaussian source would cause an error floor, while the PSK source does not, which brings nontrivial indication of constellation design as opposed to popular Gaussian-embedded literatures. We also propose an effective approach to estimate detection-required parameters rather than channels themselves. Numerical simulations are finally presented to verify theoretical results.
-
semi coherent detection and performance analysis for ambient backscatter system
IEEE Transactions on Communications, 2017Co-Authors: Jing Qian, Gongpu WangAbstract:We study a novel Communication Technique, ambient backscatter, that utilizes radio frequency signals transmitted from an ambient source as both energy supply and information carrier to enable Communications between low-power devices. Different from existing noncoherent schemes, we here design the semi-coherent detection, where channel-related parameters can be obtained from unknown data symbols and a few pilot symbols. In order to obtain a benchmark for overall detection, we first derive a maximum likelihood detector assuming a complex Gaussian ambient source, and the closed-form bit error rate (BER) is computed. To release the dependence on prior knowledge of the ambient source, we next derive a type of robust design, called an energy detector, with the ambient signal being either complex Gaussian or phase shift keying (PSK). The closed-form detection thresholds, analytical BERs, and outage probability are provided correspondingly. Interestingly, the complex Gaussian source would cause an error floor, while the PSK source does not, which brings nontrivial indication of constellation design as opposed to popular Gaussian-embedded literatures. We also propose an effective approach to estimate detection-required parameters rather than channels themselves. Numerical simulations are finally presented to verify theoretical results.