Results 1  10
of
101
Communication over mimo x channels: Interference alignment, decomposition, and performance analysis
 IEEE TRANSACTIONS ON INFORMATION THEORY
, 2008
"... In a multipleantenna system with two transmitters and two receivers, a scenario of data communication, known as the X channel, is studied in which each receiver receives data from both transmitters. In this scenario, it is assumed that each transmitter is unaware of the other transmitter’s data (n ..."
Abstract

Cited by 208 (12 self)
 Add to MetaCart
(Show Context)
In a multipleantenna system with two transmitters and two receivers, a scenario of data communication, known as the X channel, is studied in which each receiver receives data from both transmitters. In this scenario, it is assumed that each transmitter is unaware of the other transmitter’s data (noncooperative scenario). This system can be considered as a combination of two broadcast channels (from the transmitters ’ points of view) and two multipleaccess channels (from the receivers ’ points of view). Taking advantage of both perspectives, two signaling schemes for such a scenario are developed. In these schemes, some linear filters are employed at the transmitters and at the receivers which decompose the system into either two noninterfering multipleantenna broadcast subchannels or two noninterfering multipleantenna multipleaccess subchannels. The main objective in the design of the filters is to exploit the structure of the channel matrices to achieve the
Cooperative Algorithms for MIMO Interference Channels
, 2010
"... Interference alignment is a transmission technique for exploiting all available degrees of freedom in the frequencyor timeselective interference channel with an arbitrary number of users. Most prior work on interference alignment, however, neglects interference from other nodes in the network not ..."
Abstract

Cited by 65 (13 self)
 Add to MetaCart
Interference alignment is a transmission technique for exploiting all available degrees of freedom in the frequencyor timeselective interference channel with an arbitrary number of users. Most prior work on interference alignment, however, neglects interference from other nodes in the network not participating in the alignment operation. This paper proposes three generalizations of interference alignment for the multipleantenna interference channel with multiple users that account for colored noise, which models uncoordinated interference. First, a minimum interferenceplusnoise leakage (INL) algorithm is presented, and shown to be equivalent to previous subspace methods when noise is spatially white or negligible. This algorithm results in orthonormal precoders that are desirable for practical implementation with limited feedback. A joint minimum mean squared error design is then proposed that jointly optimizes the transmit precoders and receive spatial filters, whereas previous designs neglect the receive spatial filter. Finally, a maximum signaltointerferenceplusnoise ratio (SINR) algorithm is developed that is proven to converge, unlike previous maximum SINR algorithms. The sum throughput of these algorithms is simulated in the context of a network with uncoordinated cochannel interferers not participating in the alignment protocol. It is found that a network with cochannel interference can benefit from employing precoders designed to consider that interference, but in extreme cases, such as when only one receiver has a large amount of interference, ignoring the cochannel interference is advantageous.
Competitive design of multiuser MIMO systems based on game theory: A unified view
 IEEE Journal on Selected Areas in Communications
, 2008
"... Abstract—This paper considers the noncooperative maximization of mutual information in the Gaussian interference channel in a fully distributed fashion via game theory. This problem has been studied in a number of papers during the past decade for the case of frequencyselective channels. A variety ..."
Abstract

Cited by 60 (5 self)
 Add to MetaCart
(Show Context)
Abstract—This paper considers the noncooperative maximization of mutual information in the Gaussian interference channel in a fully distributed fashion via game theory. This problem has been studied in a number of papers during the past decade for the case of frequencyselective channels. A variety of conditions guaranteeing the uniqueness of the Nash Equilibrium (NE) and convergence of many different distributed algorithms have been derived. In this paper we provide a unified view of the stateoftheart results, showing that most of the techniques proposed in the literature to study the game, even though apparently different, can be unified using our recent interpretation of the waterfilling operator as a projection onto a proper polyhedral set. Based on this interpretation, we then provide a mathematical framework, useful to derive a unified set of sufficient conditions guaranteeing the uniqueness of the NE and the global convergence of waterfilling based asynchronous distributed algorithms. The proposed mathematical framework is also instrumental to study the extension of the game to the more general MIMO case, for which only few results are available in the current literature. The resulting algorithm is, similarly to the frequencyselective case, an iterative asynchronous MIMO waterfilling algorithm. The proof of convergence hinges again on the interpretation of the MIMO waterfilling as a matrix projection, which is the natural generalization of our results obtained for the waterfilling mapping in the frequencyselective case. Index Terms—Game Theory, MIMO Gaussian interference channel, Nash equilibrium, totally asynchronous algorithms, waterfilling. I.
Dynamic resource allocation in cognitive radio networks
 IEEE Signal Process. Mag
, 2010
"... ar ..."
(Show Context)
Optimal resource allocation for MIMO ad hoc cognitive radio networks
 in Proc. 46th Annu. Allerton Conf. Commun., Control, Comput
, 2008
"... Abstract—Maximization of the weighted sumrate of secondary users (SUs) possibly equipped with multiantenna transmitters and receivers is considered in the context of cognitive radio (CR) networks with coexisting primary users (PUs). The total interference power received at the primary receiver is ..."
Abstract

Cited by 39 (0 self)
 Add to MetaCart
(Show Context)
Abstract—Maximization of the weighted sumrate of secondary users (SUs) possibly equipped with multiantenna transmitters and receivers is considered in the context of cognitive radio (CR) networks with coexisting primary users (PUs). The total interference power received at the primary receiver is constrained to maintain reliable communication for the PU. An interference channel configuration is considered for ad hoc networking, where the receivers treat the interference from undesired transmitters as noise. Without the CR constraint, a convergent distributed algorithm is developed to obtain (at least) a locally optimal solution. With the CR constraint, a semidistributed algorithm is introduced. An alternative centralized algorithm based on geometric programming and network duality is also developed. Numerical results show the efficacy of the proposed algorithms. The novel approach is flexible to accommodate modifications aiming at interference alignment. However, the standalone weighted sumrate optimal schemes proposed here have merits over interferencealignment alternatives especially for practical SNR values. Index Terms—Ad hoc network, cognitive radio, interference network, MIMO, optimization. I.
Linear Transceiver Design for Interference Alignment: Complexity and Computation,” Available on arxiv:1009.3481
"... ar ..."
Decomposition by partial linearization: Parallel optimization of multiuser systems
 IEEE Trans. on Signal Processing
, 2014
"... ar ..."
(Show Context)
MIMO cognitive radio: A game theoretical approach
 in Proc. Workshop Signal Process. Adv. Wireless Commun
, 2008
"... Abstract—The concept of cognitive radio (CR) has recently received great attention from the research community as a promising paradigm to achieve efficient use of the frequency resource by allowing the coexistence of licensed (primary) and unlicensed (secondary) users in the same bandwidth. In th ..."
Abstract

Cited by 23 (3 self)
 Add to MetaCart
(Show Context)
Abstract—The concept of cognitive radio (CR) has recently received great attention from the research community as a promising paradigm to achieve efficient use of the frequency resource by allowing the coexistence of licensed (primary) and unlicensed (secondary) users in the same bandwidth. In this paper we propose and analyze a totally decentralized approach, based on game theory, to design cognitive MIMO transceivers, who compete with each other to maximize their information rate. The formulation incorporates constraints on the transmit power as well as null and/or soft shaping constraints on the transmit covariance matrix, so that the interference generated by secondary users be confined within the temperatureinterference limit required by the primary users. We provide a unified set of conditions that guarantee the uniqueness and global asymptotic stability of the Nash equilibrium of all the proposed games through totally distributed and asynchronous algorithms. Interestingly, the proposed algorithms overcome the main drawback of classical waterfilling based algorithms—the violation of the temperatureinterference limit—and they have the desired features required for CR applications, such as lowcomplexity, distributed implementation, robustness against missing or outdated updates of the users, and fast convergence behavior. Index Terms—Cognitive radio, game theory, interference constraints, MIMO Gaussian interference channel, Nash equilibrium, totally asynchronous distributed algorithms.
Optimal power schedule for distributed MIMO links
 IEEE Transactions on Wireless Communications
, 2008
"... Abstract—We present an optimal power scheduling scheme to maximize the throughput of a set of distributed multipleinput multipleoutput (MIMO) wireless links. This scheme exploits both spatial and temporal freedoms of the source covariance matrices of all MIMO links. In particular, the source covar ..."
Abstract

Cited by 22 (12 self)
 Add to MetaCart
(Show Context)
Abstract—We present an optimal power scheduling scheme to maximize the throughput of a set of distributed multipleinput multipleoutput (MIMO) wireless links. This scheme exploits both spatial and temporal freedoms of the source covariance matrices of all MIMO links. In particular, the source covariance matrix of each MIMO link is allowed to vary within a block of time (and/or frequency) slots. This scheme, also referred to as spacetime power scheduling, optimizes an integration of link scheduling and power control for MIMO links. The computational problem involved in this scheme is nonconvex. However, a gradientprojection algorithm developed for this scheme consistently yields a higher capacity than all other existing schemes. Index Terms—Network of MIMO links, medium access control, spacetime power scheduling. I.
Distributed Interference Pricing for the MIMO Interference Channel
 PROC. IEEE INTERNATIONAL CONFERENCE ON COMMUNICATIONS
, 2009
"... Abstract—We study distributed algorithms for updating transmit precoding matrices for a twouser MultiInput/MultiOutput (MIMO) interference channel. Our objective is to maximize the sum rate with linear Minimum Mean Squared Error (MMSE) receivers, treating the interference as additive Gaussian noi ..."
Abstract

Cited by 21 (2 self)
 Add to MetaCart
(Show Context)
Abstract—We study distributed algorithms for updating transmit precoding matrices for a twouser MultiInput/MultiOutput (MIMO) interference channel. Our objective is to maximize the sum rate with linear Minimum Mean Squared Error (MMSE) receivers, treating the interference as additive Gaussian noise. An iterative approach is considered in which given a set of precoding matrices and powers, each receiver announces an interference price (marginal decrease in rate due to an increase in interference) for each received beam, corresponding to a column of the precoding matrix. Given the interference prices from the neighboring receiver, and also knowledge of the appropriate crosschannel matrices, the transmitter can then update the beams and powers to maximize the rate minus the interference cost. Variations on this approach are presented in which beams are added sequentially (and then fixed), and in which all beams and associated powers are adjusted at each iteration. Numerical results are presented, which compare these algorithms with iterative waterfilling (which requires no information exchange), and a centralized optimization algorithm, which finds locally optimal solutions. Our results show that the distributed algorithms perform close to the centralized algorithm, and by adapting the rank of the precoder matrices, achieve the optimal highSNR slope. I.