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16
Impact of antenna correlation on the capacity of multiantenna channels
 IEEE TRANS. INFORM. THEORY
, 2005
"... This paper applies random matrix theory to obtain analytical characterizations of the capacity of correlated multiantenna channels. The analysis is not restricted to the popular separable correlation model, but rather it embraces a more general representation that subsumes most of the channel model ..."
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Cited by 103 (6 self)
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This paper applies random matrix theory to obtain analytical characterizations of the capacity of correlated multiantenna channels. The analysis is not restricted to the popular separable correlation model, but rather it embraces a more general representation that subsumes most of the channel models that have been treated in the literature. For arbitrary signaltonoise ratios @ A, the characterization is conducted in the regime of large numbers of antennas. For the low and high regions, in turn, we uncover compact capacity expansions that are valid for arbitrary numbers of antennas and that shed insight on how antenna correlation impacts the tradeoffs among power, bandwidth, and rate.
High SNR Analysis of MIMO Broadcast Channels
"... The behavior of the multiple antenna broadcast channel at high SNR is investigated. The multiple antenna broadcast channel achieves the same multiplexing gain as the system in which all receivers are allowed to perfectly cooperate (i.e. transforming the system into a pointtopoint MIMO system). H ..."
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Cited by 38 (8 self)
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The behavior of the multiple antenna broadcast channel at high SNR is investigated. The multiple antenna broadcast channel achieves the same multiplexing gain as the system in which all receivers are allowed to perfectly cooperate (i.e. transforming the system into a pointtopoint MIMO system). However, the multiplexing gain alone is not sufficient to accurately characterize the behavior of sum rate capacity at high SNR. An affine approximation to capacity which incorporates the multiplexing gain as well as a power offset (i.e. a zeroorder term) is a more accurate representation of high SNR behavior. The power offset of the sum rate capacity is shown to equal the power offset of the cooperative MIMO system when there are less receivers than transmit antennas. In addition, the power offset of using the suboptimal strategy of beamforming is calculated. These calculations show that beamforming can perform quite well when the number of antennas is sufficiently larger than the number of receivers, but performs very poorly when there are nearly as many receivers as transmit antennas.
A Central Limit Theorem for the SINR at the LMMSE Estimator Output for Large Dimensional Signals
, 2008
"... This paper is devoted to the performance study of the Linear Minimum Mean Squared Error estimator for multidimensional signals in the large dimension regime. Such an estimator is frequently encountered in wireless communications and in array processing, and the Signal to Interference and Noise Ratio ..."
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Cited by 18 (8 self)
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This paper is devoted to the performance study of the Linear Minimum Mean Squared Error estimator for multidimensional signals in the large dimension regime. Such an estimator is frequently encountered in wireless communications and in array processing, and the Signal to Interference and Noise Ratio (SINR) at its output is a popular performance index. The SINR can be modeled as a random quadratic form which can be studied with the help of large random matrix theory, if one assumes that the dimension of the received and transmitted signals go to infinity at the same pace. This paper considers the asymptotic behavior of the SINR for a wide class of multidimensional signal models that includes general multiantenna as well as spread spectrum transmission models. The expression of the deterministic approximation of the SINR in the large dimension regime is recalled and the SINR fluctuations around this deterministic approximation are studied. These fluctuations are shown to converge in distribution to the Gaussian law in the large dimension regime, and their variance is shown to decrease as the inverse of the signal dimension.
NonAtomic Games for MultiUser Systems
"... In this contribution, the performance of a multiuser system is analyzed in the context of frequency selective fading channels. Using game theoretic tools, a useful framework is provided in order to determine the optimal power allocation when users know only their own channel (while perfect channel ..."
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Cited by 16 (6 self)
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In this contribution, the performance of a multiuser system is analyzed in the context of frequency selective fading channels. Using game theoretic tools, a useful framework is provided in order to determine the optimal power allocation when users know only their own channel (while perfect channel state information is assumed at the base station). This scenario illustrates the case of decentralized schemes, where limited information on the network is available at the terminal. Various receivers are considered, namely the matched filter, the MMSE filter and the optimum filter. The goal of this paper is to extend previous work, and to derive simple expressions for the noncooperative Nash equilibrium as the number of mobiles becomes large and the spreading length increases. To that end two asymptotic methodologies are combined. The first is asymptotic random matrix theory which allows us to obtain explicit expressions of the impact of all other mobiles on any given tagged mobile. The second is the theory of nonatomic games which computes good approximations of the Nash equilibrium as the number of mobiles grows.
Wardrop Equilibrium for CDMA Systems
"... Abstract — In this contribution, the performance of an uplink CDMA system is analyzed in the context of frequency selective fading channels. Using game theoretic tools, a useful framework is provided in order to determine the optimal power allocation when users know only their own channel (while per ..."
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Cited by 6 (1 self)
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Abstract — In this contribution, the performance of an uplink CDMA system is analyzed in the context of frequency selective fading channels. Using game theoretic tools, a useful framework is provided in order to determine the optimal power allocation when users know only their own channel (while perfect channel state information is assumed at the base station). We consider the realistic case of frequency selective channels. This scenario illustrates the case of decentralized schemes and aims at reducing the downlink signaling overhead. Various receivers are considered, namely the Matched filter, the MMSE filter and the optimum filter. The goal of this paper is to derive simple expressions for the noncooperative Nash equilibrium as the number of mobiles becomes large. To that end we combine two asymptotic methodologies. The first is asymptotic random matrix theory which allows us to obtain explicit expressions for the impact of all other mobiles on any given tagged mobile. The second is the theory of nonatomic games along with the Wardrop equilibrium concept which allows us to compute good approximations of the Nash equilibrium as the number of mobiles grow. 1 I.
Filterbank multicarrier and multicarrier cdma for cognitive radio systems
 IEEE CrownCom
, 2007
"... Recent works in cognitive radio (CR) have suggested multicarrier communication based on orthogonal frequencydivision multiplexing (OFDM) for CR networks. In this paper, we propose two alternative multicarrier techniques. The first one, filterbankbased OFDMOQAM (OFDMoffset quadrature amplitude mo ..."
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Cited by 4 (1 self)
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Recent works in cognitive radio (CR) have suggested multicarrier communication based on orthogonal frequencydivision multiplexing (OFDM) for CR networks. In this paper, we propose two alternative multicarrier techniques. The first one, filterbankbased OFDMOQAM (OFDMoffset quadrature amplitude modulation), permits to maximize the secondary users ’ spectral efficiency by eliminating the need for guard bands. Also, OFDMOQAM’s filterbank spectral estimator has greater dynamic range than the conventional fast fourier transform in OFDM, which further reduces the probability of undesirable collisions between the secondary users (SU) and primary users (PU). However, OFDMOQAM still requires an SU base station for distributed sensing. The number and the frequency of required sensing messages for uninterrupted PU operation depends on the randomness of the PU processes. We establish the cost of the CR methodology in the form of signaling bits per bit of payload data and relate our simulation results to the entropy of our PU processes by modeling the behavior of the PUs as finite state Markov chains. For cases where sensing is not available, when sensing information cannot be conveyed, or when the entropy of the PU processes results in unacceptable sensingtopayload overhead, we suggest another multicarrier technique, namely multicarrier code division multiple access (MCCDMA). While MCCDMA does not achieve comparably high spectral efficiency as OFDMOQAM, the spreading gain of MCCDMA results in graceful degradation in the case of collisions between PUs and SUs. Furthermore, compared to direct sequence (DS) CDMA, MCCDMA can exclude narrowband PU interferers locally at the SU receiver, hence improving SU performance. We show that MCCDMA makes it possible to operate the SU network without distributed sensing and hence without a base station infrastructure and/or a signaling channel.
Optimal decoding order under target rate constraints
 PROC. 8TH IEEE INT. WORKSHOP ON SIGNAL PROCESSING ADVANCES FOR WIRELESS COMMUNICATIONS
, 2007
"... In this contribution, we derive the optimal power allocation under target rate constraints in the case of an uplink multiuser system. Using asymptotic results based on random matrix theory, we provide a unified framework for determining the optimal decoding order when using Successive Interference C ..."
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Cited by 4 (1 self)
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In this contribution, we derive the optimal power allocation under target rate constraints in the case of an uplink multiuser system. Using asymptotic results based on random matrix theory, we provide a unified framework for determining the optimal decoding order when using Successive Interference Cancellation (SIC) receivers, namely the MMSE (Minimum Mean Square Error) and Matched filter SIC. Moreover, for decentralized systems, we show that each user can, under certain conditions, solely determine the power allocation based only on his channel energy and the statistics of the other users. Simulations in the case of finite systems validate the asymptotic claims.
Final
"... D1.3.1 The initial mathematical models of new BIONETS network elements and algorithms Reference: ..."
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D1.3.1 The initial mathematical models of new BIONETS network elements and algorithms Reference:
SUMMARY
, 2007
"... D1.3.2 BIONETS simulation framework and initial performance analysis ..."
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MATRICES ALÉATOIRES ET APPLICATIONS AUX COMMUNICATIONS NUMÉRIQUES
, 2010
"... C’est avec un grand plaisir que je dédie cette page à toutes les personnes qui ont contribuées de près ou de loin à la réussite de ma thèse. Les premières personnes que je tiens à remercier sont Walid Hachem et Jamal Najim, mes directeurs de thèse. Je les remercie pour l’aide scientifique précieuse, ..."
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C’est avec un grand plaisir que je dédie cette page à toutes les personnes qui ont contribuées de près ou de loin à la réussite de ma thèse. Les premières personnes que je tiens à remercier sont Walid Hachem et Jamal Najim, mes directeurs de thèse. Je les remercie pour l’aide scientifique précieuse, pour leur disponibilité et pour leurs conseils avisés. Qu’ils trouvent ici mes profonds remerciements et reconnaissance. Je suis également reconnaissante à Ahmed Elkharroubi d’avoir assuré mon encadrement au sein du département de Mathématiques et Informatique à l’Université Hassan II Ain