87 mohamed Mabrouk marey | Alexandria University ,Egypt (original) (raw)
Papers by 87 mohamed Mabrouk marey
Ieee Vehicular Technology Conference, 2006
In orthogonal frequency division multiplexed (OFDM) systems affected by carrier frequency offsets... more In orthogonal frequency division multiplexed (OFDM) systems affected by carrier frequency offsets, frequency ambiguity resolution, i.e. the estimation of the part of the frequency offset corresponding to an integer times the carrier spacing is a crucial issue. The proper action of frequency ambiguity resolution algorithms can be strongly affected by the presence of disturbances, like narrowband interference (NBI). In this paper, the susceptibility of the blind and data aided maximum likelihood (ML) frequency ambiguity estimators to NBI signals, which may arise in the OFDM band as the spectrum becomes more crowded, is investigated in an analytical way. The analytical results are verified by means of simulations. Although the estimators turn out to be essentially independent of the bandwidth of the interferers and the number of interferers, the performance of the estimators is very sensitive to the positions of the interferers when the interferers are strong.
2007 Ieee 65th Vehicular Technology Conference Vtc2007 Spring, 2007
Spectrum-overlay scenarios for wideband multicarrier (MC) systems bring new technical challenges ... more Spectrum-overlay scenarios for wideband multicarrier (MC) systems bring new technical challenges that must be considered during the system design. In such a scenario, the receiver has to perform actions, such as channel estimation and synchronization, in the presence of possibly strong in-band interference. In this paper, we modify the iterative maximum likelihood joint frame synchronization and channel estimation algorithm for downlink MC-CDMA presented in [1] to have better performance in the presence of narrowband interference. The performance of the modified algorithm is verified through computer simulations and compared with the original one.
Ieee Transactions on Wireless Communications, Apr 1, 2008
In this contribution, we propose a new code-aided synchronization and channel estimation algorith... more In this contribution, we propose a new code-aided synchronization and channel estimation algorithm for uplink MC-CDMA. The space alternating generalized expectationmaximization (SAGE) algorithm is used to estimate the channel impulse responses, propagation delays and carrier frequency offsets of the different users. The estimator, multiuser detector, equalizer, demapper and channel decoder exchange soft information in an iterative way. The performance of the proposed algorithm is evaluated through Monte Carlo simulations. Impressive performance gains are visible as compared to a conventional data-aided estimation scheme.
IEEE Communications Letters, 2014
ABSTRACT Blind estimation algorithms offer possibilities for improving the throughput of communic... more ABSTRACT Blind estimation algorithms offer possibilities for improving the throughput of communications systems by reducing the overhead that would otherwise be required for the estimation of parameters needed for operations such as block timing and carrier frequency synchronization. Additionally, they are required by emerging cognitive radios to provide spectrum awareness functionality. When compared with the existing literature, in this letter we propose a blind block timing and carrier frequency synchronization algorithm applicable to orthogonal space-time block code systems. By exploiting the space-time redundancy of the received signal when two receive antennas are employed, this algorithm estimates the synchronization parameters using second-order statistics without requiring a priori knowledge of the channel coefficients or signal-to-noise ratio. Furthermore, it does not depend on accurate clock timing synchronization, which is confirmed by simulation experiments.
Journal of Reproduction and Development, 2014
We have previously shown that polymorphonuclear neutrophils (PMNs) are present in bovine oviduct ... more We have previously shown that polymorphonuclear neutrophils (PMNs) are present in bovine oviduct fluid under physiological conditions, and that the oviduct provides a microenvironment that protects sperm from phagocytosis by PMNs. Alpha 1-acid glycoprotein (AGP) is a major acute-phase protein produced mainly in the liver that has immunomodulatory functions. AGP mRNA is expressed in extrahepatic organs, such as the lung, kidney, spleen, lymph node, uterus, and ovary. Therefore, in this study, we investigated, 1) the local production of AGP in the bovine oviduct, 2) the effect of AGP on the phagocytic activity of PMNs for sperm and superoxide production and 3) the impact of AGP desialylation on the PMN phagocytosis of sperm. The AGP gene was expressed in cultured bovine oviduct epithelial cells (BOECs) and AGP protein was detected in oviduct fluid. Preexposure of PMNs to AGP at physiological levels impaired PMN phagocytosis for sperm and superoxide generation. The desialylation of AGP eliminated these suppressive effects of AGP on PMN. Scanning electron microscopy revealed that AGP drastically reduced the formation of DNA-based neutrophil extracellular traps (NETs) for sperm entanglement. Additionally, AGP dose-dependently stimulated BOECs to produce prostaglandin E 2 (PGE 2) which has been shown to partially contribute to the regulation of sperm phagocytosis in the bovine oviduct. AGP and PGE 2 at concentrations detected in the oviducts additively suppressed sperm phagocytosis by PMNs. These results provide evidence that locally produced AGP may be involved in protecting sperm from phagocytosis by PMNs in the bovine oviduct.
2011 IEEE 16th International Workshop on Computer Aided Modeling and Design of Communication Links and Networks (CAMAD), 2011
In this paper, we study partially overlapping coexistence scenarios in cognitive radio environmen... more In this paper, we study partially overlapping coexistence scenarios in cognitive radio environment. We consider an Orthogonal Frequency Division Multiplexing (OFDM) cognitive system coexisting with a narrow-band (NB) and an OFDM primary system, respectively. We focus on finding the minimum frequency separation between the coexisting systems to meet a certain target BER. Windowing and nulling are used as simple techniques to reduce the OFDM out-of-band radiations, and, hence decrease the separation. The effect of these techniques on the OFDM spectral efficiency and PAPR is also studied.
Lecture Notes Electrical Engineering, 2007
Spectrum-overlay scenarios for wideband multi-carrier (MC) systems bring new technical challenges... more Spectrum-overlay scenarios for wideband multi-carrier (MC) systems bring new technical challenges that must be considered during the system design. In such a scenario, the performance of the multi-carrier system is affected by the presence of possibly strong in-band interference. To improve the performance of the MC communication link in an interference corrupted environment (without increasing transmit bandwidth), the interference must be estimated and removed. In this paper, we propose a new low complexity algorithm to estimate and suppress digitally modulated interferers located in the MC spectrum. The performance of the interference suppression is evaluated in an analytical way. Further, simulations have been carried out to verify the validity of approximations in the analysis.
IEEE Transactions on Vehicular Technology, 2014
ABSTRACT
2011 IEEE Global Telecommunications Conference - GLOBECOM 2011, 2011
Abstract In this paper, we propose maximum likelihood (ML) detectors to mitigate the influence of... more Abstract In this paper, we propose maximum likelihood (ML) detectors to mitigate the influence of the interference signal for the two-relays full-rate cooperative systems. At the relays, the proposed ML detector is employed by averaging out the interference signal. ...
2012 IEEE Radio and Wireless Symposium, 2012
Cognitive radios hold tremendous promise for increasing the spectral efficiency of wireless commu... more Cognitive radios hold tremendous promise for increasing the spectral efficiency of wireless communication systems. In this paper, an adaptive bit allocation algorithm is presented for orthogonal frequency division multiplexing (OFDM) CR systems operating in a frequency selective fading environment. The algorithm maximizes the CR system throughput in the presence of narrowband interference, while guaranteeing a BER below a predefined threshold. The effect of imperfect channel estimation on the algorithm's performance is also studied.
VTC Spring 2008 - IEEE Vehicular Technology Conference, 2008
The estimation and tracking of the fractional carrier frequency offset (CFO) is a crucial issue i... more The estimation and tracking of the fractional carrier frequency offset (CFO) is a crucial issue in the implementation of orthogonal frequency division multiplexing (OFDM) systems. In this contribution, we present a novel code-aided fractional CFO estimation algorithm based on the Expectation-Maximization (EM) algorithm. The proposed algorithm exchanges soft information from the channel decoder, in the form of a posteriori probabilities of the coded symbols, between the demapper, the decoder, and the CFO estimator in an iterative way. The proposed estimation scheme can work with any detector as long as the detector is able to compute the a posteriori probabilities (APPs) of the data symbols.
IEEE Vehicular Technology Conference, 2006
In orthogonal frequency division multiplexed (OFDM) systems affected by carrier frequency offsets... more In orthogonal frequency division multiplexed (OFDM) systems affected by carrier frequency offsets, frequency ambiguity resolution, i.e. the estimation of the part of the frequency offset corresponding to an integer times the carrier spacing is a crucial issue. The proper action of frequency ambiguity resolution algorithms can be strongly affected by the presence of disturbances, like narrowband interference (NBI). In this paper, the susceptibility of the blind and data aided maximum likelihood (ML) frequency ambiguity estimators to NBI signals, which may arise in the OFDM band as the spectrum becomes more crowded, is investigated in an analytical way. The analytical results are verified by means of simulations. Although the estimators turn out to be essentially independent of the bandwidth of the interferers and the number of interferers, the performance of the estimators is very sensitive to the positions of the interferers when the interferers are strong.
2010 IEEE 72nd Vehicular Technology Conference - Fall, 2010
In this paper, we develop a new algorithm to jointly estimate the channel impulse response and in... more In this paper, we develop a new algorithm to jointly estimate the channel impulse response and inphase-quadrature (IQ) imbalances for OFDM systems. The estimation algorithm is based on the expectation maximization (EM) algorithm, exploiting information from the pilot symbols and detected data symbols in a systematic fashion. To reduce the complexity of the estimation algorithm, a suboptimal scheme is also introduced. The results indicate that the proposed algorithms achieve a significant improvement in the bit error rate (BER) performance when compared with conventional data-aided algorithms.
2013 IEEE Global Communications Conference (GLOBECOM), 2013
This paper proposes a novel and efficient algorithm for space-time block code (STBC) classificati... more This paper proposes a novel and efficient algorithm for space-time block code (STBC) classification, when a single antenna is employed at the receiver. The algorithm exploits the discriminating features provided by the discrete Fourier transform (DFT) of the fourth-order lag products (FOLPs) of the received signal. It does not require estimation of the channel, signal-to-noise ratio (SNR), and modulation of the transmitted signal. Computer simulations are conducted to evaluate the performance of the proposed algorithm. The results show the validity of the algorithm, its robustness to carrier frequency offset, and low sensitivity to timing offset.
2007 IEEE 65th Vehicular Technology Conference - VTC2007-Spring, 2007
Spectrum-overlay scenarios for wideband multicarrier (MC) systems bring new technical challenges ... more Spectrum-overlay scenarios for wideband multicarrier (MC) systems bring new technical challenges that must be considered during the system design. In such a scenario, the receiver has to perform actions, such as channel estimation and synchronization, in the presence of possibly strong in-band interference. In this paper, we modify the iterative maximum likelihood joint frame synchronization and channel estimation algorithm for downlink MC-CDMA presented in [1] to have better performance in the presence of narrowband interference. The performance of the modified algorithm is verified through computer simulations and compared with the original one.
Proceedings of the 2nd international conference on Mobile multimedia communications - MobiMedia '06, 2006
In orthogonal frequency division multiplexing (OFDM) systems affected by carrier frequency offset... more In orthogonal frequency division multiplexing (OFDM) systems affected by carrier frequency offsets, the estimation of the frequency offset corresponding to a fractional part of the carrier spacing is a crucial issue. The proper action of the fractional frequency estimator can be strongly affected by the presence of disturbances, like narrowband interference (NBI) signals. In this paper, we derive the data-aided maximum-likelihood (ML) fractional frequency estimator in the presence of (NBI). Based on the ML algorithm which has a high complexity, we propose a number of simplifications to develop a lower complexity algorithm. The susceptibility of the simplified fractional frequency estimator to NBI signals is investigated in an analytical way. The analytical results are verified by means of simulations. Although the simplified estimator turns out to be essentially independent of the bandwidth and the location of interferers, the performance of the estimator is very sensitive to the signal to interference ratio and the number of interferers. In contrast with the simplified estimator, simulation results indicate that the exact ML estimator is essentially independent of the (NBI) signals.
2012 IEEE International Conference on Communications (ICC), 2012
In this paper, a novel low complexity bit and power loading algorithm is formulated for orthogona... more In this paper, a novel low complexity bit and power loading algorithm is formulated for orthogonal frequency division multiplexing (OFDM) systems operating in fading environments and in the presence of unknown interference. The proposed non-iterative algorithm jointly maximizes the throughput and minimizes the transmitted power, while guaranteeing a target bit error rate (BER) per subcarrier. Closedform expressions are derived for the optimal bit and power distributions per subcarrier. The performance of the proposed algorithm is investigated through extensive simulations. A performance comparison with the algorithm in [1] shows the superiority of the proposed algorithm with reduced computational effort.
2011 IEEE International Conference on Communications (ICC), 2011
AbstractA key issue in the full-rate two-relay cooper-ative communication systems is the interfe... more AbstractA key issue in the full-rate two-relay cooper-ative communication systems is the interference which is caused by the simultaneous transmission of the source and one of the relays at any time. In this paper, we exploit the interference signal at the destination to develop a ...
Ieee Vehicular Technology Conference, 2006
In orthogonal frequency division multiplexed (OFDM) systems affected by carrier frequency offsets... more In orthogonal frequency division multiplexed (OFDM) systems affected by carrier frequency offsets, frequency ambiguity resolution, i.e. the estimation of the part of the frequency offset corresponding to an integer times the carrier spacing is a crucial issue. The proper action of frequency ambiguity resolution algorithms can be strongly affected by the presence of disturbances, like narrowband interference (NBI). In this paper, the susceptibility of the blind and data aided maximum likelihood (ML) frequency ambiguity estimators to NBI signals, which may arise in the OFDM band as the spectrum becomes more crowded, is investigated in an analytical way. The analytical results are verified by means of simulations. Although the estimators turn out to be essentially independent of the bandwidth of the interferers and the number of interferers, the performance of the estimators is very sensitive to the positions of the interferers when the interferers are strong.
2007 Ieee 65th Vehicular Technology Conference Vtc2007 Spring, 2007
Spectrum-overlay scenarios for wideband multicarrier (MC) systems bring new technical challenges ... more Spectrum-overlay scenarios for wideband multicarrier (MC) systems bring new technical challenges that must be considered during the system design. In such a scenario, the receiver has to perform actions, such as channel estimation and synchronization, in the presence of possibly strong in-band interference. In this paper, we modify the iterative maximum likelihood joint frame synchronization and channel estimation algorithm for downlink MC-CDMA presented in [1] to have better performance in the presence of narrowband interference. The performance of the modified algorithm is verified through computer simulations and compared with the original one.
Ieee Transactions on Wireless Communications, Apr 1, 2008
In this contribution, we propose a new code-aided synchronization and channel estimation algorith... more In this contribution, we propose a new code-aided synchronization and channel estimation algorithm for uplink MC-CDMA. The space alternating generalized expectationmaximization (SAGE) algorithm is used to estimate the channel impulse responses, propagation delays and carrier frequency offsets of the different users. The estimator, multiuser detector, equalizer, demapper and channel decoder exchange soft information in an iterative way. The performance of the proposed algorithm is evaluated through Monte Carlo simulations. Impressive performance gains are visible as compared to a conventional data-aided estimation scheme.
IEEE Communications Letters, 2014
ABSTRACT Blind estimation algorithms offer possibilities for improving the throughput of communic... more ABSTRACT Blind estimation algorithms offer possibilities for improving the throughput of communications systems by reducing the overhead that would otherwise be required for the estimation of parameters needed for operations such as block timing and carrier frequency synchronization. Additionally, they are required by emerging cognitive radios to provide spectrum awareness functionality. When compared with the existing literature, in this letter we propose a blind block timing and carrier frequency synchronization algorithm applicable to orthogonal space-time block code systems. By exploiting the space-time redundancy of the received signal when two receive antennas are employed, this algorithm estimates the synchronization parameters using second-order statistics without requiring a priori knowledge of the channel coefficients or signal-to-noise ratio. Furthermore, it does not depend on accurate clock timing synchronization, which is confirmed by simulation experiments.
Journal of Reproduction and Development, 2014
We have previously shown that polymorphonuclear neutrophils (PMNs) are present in bovine oviduct ... more We have previously shown that polymorphonuclear neutrophils (PMNs) are present in bovine oviduct fluid under physiological conditions, and that the oviduct provides a microenvironment that protects sperm from phagocytosis by PMNs. Alpha 1-acid glycoprotein (AGP) is a major acute-phase protein produced mainly in the liver that has immunomodulatory functions. AGP mRNA is expressed in extrahepatic organs, such as the lung, kidney, spleen, lymph node, uterus, and ovary. Therefore, in this study, we investigated, 1) the local production of AGP in the bovine oviduct, 2) the effect of AGP on the phagocytic activity of PMNs for sperm and superoxide production and 3) the impact of AGP desialylation on the PMN phagocytosis of sperm. The AGP gene was expressed in cultured bovine oviduct epithelial cells (BOECs) and AGP protein was detected in oviduct fluid. Preexposure of PMNs to AGP at physiological levels impaired PMN phagocytosis for sperm and superoxide generation. The desialylation of AGP eliminated these suppressive effects of AGP on PMN. Scanning electron microscopy revealed that AGP drastically reduced the formation of DNA-based neutrophil extracellular traps (NETs) for sperm entanglement. Additionally, AGP dose-dependently stimulated BOECs to produce prostaglandin E 2 (PGE 2) which has been shown to partially contribute to the regulation of sperm phagocytosis in the bovine oviduct. AGP and PGE 2 at concentrations detected in the oviducts additively suppressed sperm phagocytosis by PMNs. These results provide evidence that locally produced AGP may be involved in protecting sperm from phagocytosis by PMNs in the bovine oviduct.
2011 IEEE 16th International Workshop on Computer Aided Modeling and Design of Communication Links and Networks (CAMAD), 2011
In this paper, we study partially overlapping coexistence scenarios in cognitive radio environmen... more In this paper, we study partially overlapping coexistence scenarios in cognitive radio environment. We consider an Orthogonal Frequency Division Multiplexing (OFDM) cognitive system coexisting with a narrow-band (NB) and an OFDM primary system, respectively. We focus on finding the minimum frequency separation between the coexisting systems to meet a certain target BER. Windowing and nulling are used as simple techniques to reduce the OFDM out-of-band radiations, and, hence decrease the separation. The effect of these techniques on the OFDM spectral efficiency and PAPR is also studied.
Lecture Notes Electrical Engineering, 2007
Spectrum-overlay scenarios for wideband multi-carrier (MC) systems bring new technical challenges... more Spectrum-overlay scenarios for wideband multi-carrier (MC) systems bring new technical challenges that must be considered during the system design. In such a scenario, the performance of the multi-carrier system is affected by the presence of possibly strong in-band interference. To improve the performance of the MC communication link in an interference corrupted environment (without increasing transmit bandwidth), the interference must be estimated and removed. In this paper, we propose a new low complexity algorithm to estimate and suppress digitally modulated interferers located in the MC spectrum. The performance of the interference suppression is evaluated in an analytical way. Further, simulations have been carried out to verify the validity of approximations in the analysis.
IEEE Transactions on Vehicular Technology, 2014
ABSTRACT
2011 IEEE Global Telecommunications Conference - GLOBECOM 2011, 2011
Abstract In this paper, we propose maximum likelihood (ML) detectors to mitigate the influence of... more Abstract In this paper, we propose maximum likelihood (ML) detectors to mitigate the influence of the interference signal for the two-relays full-rate cooperative systems. At the relays, the proposed ML detector is employed by averaging out the interference signal. ...
2012 IEEE Radio and Wireless Symposium, 2012
Cognitive radios hold tremendous promise for increasing the spectral efficiency of wireless commu... more Cognitive radios hold tremendous promise for increasing the spectral efficiency of wireless communication systems. In this paper, an adaptive bit allocation algorithm is presented for orthogonal frequency division multiplexing (OFDM) CR systems operating in a frequency selective fading environment. The algorithm maximizes the CR system throughput in the presence of narrowband interference, while guaranteeing a BER below a predefined threshold. The effect of imperfect channel estimation on the algorithm's performance is also studied.
VTC Spring 2008 - IEEE Vehicular Technology Conference, 2008
The estimation and tracking of the fractional carrier frequency offset (CFO) is a crucial issue i... more The estimation and tracking of the fractional carrier frequency offset (CFO) is a crucial issue in the implementation of orthogonal frequency division multiplexing (OFDM) systems. In this contribution, we present a novel code-aided fractional CFO estimation algorithm based on the Expectation-Maximization (EM) algorithm. The proposed algorithm exchanges soft information from the channel decoder, in the form of a posteriori probabilities of the coded symbols, between the demapper, the decoder, and the CFO estimator in an iterative way. The proposed estimation scheme can work with any detector as long as the detector is able to compute the a posteriori probabilities (APPs) of the data symbols.
IEEE Vehicular Technology Conference, 2006
In orthogonal frequency division multiplexed (OFDM) systems affected by carrier frequency offsets... more In orthogonal frequency division multiplexed (OFDM) systems affected by carrier frequency offsets, frequency ambiguity resolution, i.e. the estimation of the part of the frequency offset corresponding to an integer times the carrier spacing is a crucial issue. The proper action of frequency ambiguity resolution algorithms can be strongly affected by the presence of disturbances, like narrowband interference (NBI). In this paper, the susceptibility of the blind and data aided maximum likelihood (ML) frequency ambiguity estimators to NBI signals, which may arise in the OFDM band as the spectrum becomes more crowded, is investigated in an analytical way. The analytical results are verified by means of simulations. Although the estimators turn out to be essentially independent of the bandwidth of the interferers and the number of interferers, the performance of the estimators is very sensitive to the positions of the interferers when the interferers are strong.
2010 IEEE 72nd Vehicular Technology Conference - Fall, 2010
In this paper, we develop a new algorithm to jointly estimate the channel impulse response and in... more In this paper, we develop a new algorithm to jointly estimate the channel impulse response and inphase-quadrature (IQ) imbalances for OFDM systems. The estimation algorithm is based on the expectation maximization (EM) algorithm, exploiting information from the pilot symbols and detected data symbols in a systematic fashion. To reduce the complexity of the estimation algorithm, a suboptimal scheme is also introduced. The results indicate that the proposed algorithms achieve a significant improvement in the bit error rate (BER) performance when compared with conventional data-aided algorithms.
2013 IEEE Global Communications Conference (GLOBECOM), 2013
This paper proposes a novel and efficient algorithm for space-time block code (STBC) classificati... more This paper proposes a novel and efficient algorithm for space-time block code (STBC) classification, when a single antenna is employed at the receiver. The algorithm exploits the discriminating features provided by the discrete Fourier transform (DFT) of the fourth-order lag products (FOLPs) of the received signal. It does not require estimation of the channel, signal-to-noise ratio (SNR), and modulation of the transmitted signal. Computer simulations are conducted to evaluate the performance of the proposed algorithm. The results show the validity of the algorithm, its robustness to carrier frequency offset, and low sensitivity to timing offset.
2007 IEEE 65th Vehicular Technology Conference - VTC2007-Spring, 2007
Spectrum-overlay scenarios for wideband multicarrier (MC) systems bring new technical challenges ... more Spectrum-overlay scenarios for wideband multicarrier (MC) systems bring new technical challenges that must be considered during the system design. In such a scenario, the receiver has to perform actions, such as channel estimation and synchronization, in the presence of possibly strong in-band interference. In this paper, we modify the iterative maximum likelihood joint frame synchronization and channel estimation algorithm for downlink MC-CDMA presented in [1] to have better performance in the presence of narrowband interference. The performance of the modified algorithm is verified through computer simulations and compared with the original one.
Proceedings of the 2nd international conference on Mobile multimedia communications - MobiMedia '06, 2006
In orthogonal frequency division multiplexing (OFDM) systems affected by carrier frequency offset... more In orthogonal frequency division multiplexing (OFDM) systems affected by carrier frequency offsets, the estimation of the frequency offset corresponding to a fractional part of the carrier spacing is a crucial issue. The proper action of the fractional frequency estimator can be strongly affected by the presence of disturbances, like narrowband interference (NBI) signals. In this paper, we derive the data-aided maximum-likelihood (ML) fractional frequency estimator in the presence of (NBI). Based on the ML algorithm which has a high complexity, we propose a number of simplifications to develop a lower complexity algorithm. The susceptibility of the simplified fractional frequency estimator to NBI signals is investigated in an analytical way. The analytical results are verified by means of simulations. Although the simplified estimator turns out to be essentially independent of the bandwidth and the location of interferers, the performance of the estimator is very sensitive to the signal to interference ratio and the number of interferers. In contrast with the simplified estimator, simulation results indicate that the exact ML estimator is essentially independent of the (NBI) signals.
2012 IEEE International Conference on Communications (ICC), 2012
In this paper, a novel low complexity bit and power loading algorithm is formulated for orthogona... more In this paper, a novel low complexity bit and power loading algorithm is formulated for orthogonal frequency division multiplexing (OFDM) systems operating in fading environments and in the presence of unknown interference. The proposed non-iterative algorithm jointly maximizes the throughput and minimizes the transmitted power, while guaranteeing a target bit error rate (BER) per subcarrier. Closedform expressions are derived for the optimal bit and power distributions per subcarrier. The performance of the proposed algorithm is investigated through extensive simulations. A performance comparison with the algorithm in [1] shows the superiority of the proposed algorithm with reduced computational effort.
2011 IEEE International Conference on Communications (ICC), 2011
AbstractA key issue in the full-rate two-relay cooper-ative communication systems is the interfe... more AbstractA key issue in the full-rate two-relay cooper-ative communication systems is the interference which is caused by the simultaneous transmission of the source and one of the relays at any time. In this paper, we exploit the interference signal at the destination to develop a ...