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15
Energy-Efficient Precoding for Multiple-Antenna Terminals
, 2011
"... The problem of energy-efficient precoding is investigated when the terminals in the system are equipped with multiple antennas. Considering static and fast-fading multiple-input multiple-output (MIMO) channels, the energy-efficiency is defined as the transmission rate to power ratio and shown to be ..."
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Cited by 26 (10 self)
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The problem of energy-efficient precoding is investigated when the terminals in the system are equipped with multiple antennas. Considering static and fast-fading multiple-input multiple-output (MIMO) channels, the energy-efficiency is defined as the transmission rate to power ratio and shown to be maximized at low transmit power. The most interesting case is the one of slow fading MIMO channels. For this type of channels, the optimal precoding scheme is generally not trivial. Furthermore, using all the available transmit power is not always optimal in the sense of energy-efficiency [which, in this case, corresponds to the communication-theoretic definition of the goodput-to-power (GPR) ratio]. Finding the optimal precoding matrices is shown to be a new open problem and is solved in several special cases: 1. when there is only one receive antenna; 2. in the low or high signal-to-noise ratio regime; 3. when uniform power allocation and the regime of large numbers of antennas are assumed. A complete numerical analysis is provided to illustrate the derived results and stated conjectures. In particular, the impact of the number of antennas on the energy-efficiency is assessed and shown to be significant.
Energy-efficient resource allocation in multiuser MIMO systems: a game-theoretic framework
- CoRR
"... This paper focuses on the cross-layer issue of resource allocation for energy efficiency in the uplink of a multiuser MIMO wireless communication system. Assuming that all of the transmitters and the uplink receiver are equipped with multiple antennas, the situation considered is that in which each ..."
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Cited by 7 (1 self)
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This paper focuses on the cross-layer issue of resource allocation for energy efficiency in the uplink of a multiuser MIMO wireless communication system. Assuming that all of the transmitters and the uplink receiver are equipped with multiple antennas, the situation considered is that in which each terminal is allowed to vary its transmit power, beamforming vector, and uplink receiver in order to maximize its own utility, which is defined as the ratio of data throughput to transmit power; the case in which non-linear interference cancellation is used at the receiver is also investigated. Applying a game-theoretic formulation, several non-cooperative games for utility maximization are thus formulated, and their performance is compared in terms of achieved average utility, achieved average SINR and average transmit power at the Nash equilibrium. Numerical results show that the use of the proposed cross-layer resource allocation policies brings remarkable advantages to the network performance. 1.
Joint Waveform Adaptation and Power Control in Multi-Cell Wireless Data Networks: A Game-Theoretic Approach
, 2010
"... Abstract—The problem of non-cooperative spreading code allocation, linear receiver design, and transmit power control for multicell wireless networks is considered in this paper. Several utility functions to be maximized are considered, and, among them, we cite the received SINR, and the transmitter ..."
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Cited by 1 (1 self)
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Abstract—The problem of non-cooperative spreading code allocation, linear receiver design, and transmit power control for multicell wireless networks is considered in this paper. Several utility functions to be maximized are considered, and, among them, we cite the received SINR, and the transmitter energy efficiency, which is measured in bit/Joule, and represents the number of successfully delivered bits for each energy unit used for transmission. Resorting to the theory of potential games, non-cooperative games admitting Nash equilibria in multi-cell networks regardless of the channel coefficient realizations are designed. Computer simulations confirm that the considered games are convergent, and show the huge benefits that resource allocation schemes can bring to the performance of wireless data networks. Index Terms—Multicell networks, potential games, energyefficiency, waveform adaptation, power control. I.
EMA: Energy-efficiency-aware multiple access
- IEEE Commun. Lett
, 2014
"... Abstract—To improve the energy efficiency (EE) of an orthogo-nal frequency-division multiple access system with multiple trans-mit antennas supporting multiple single-receive-antenna users, we propose an EE-aware multiple access (EMA) scheme. The EMA selects an energy-efficient channel access method ..."
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Cited by 1 (1 self)
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Abstract—To improve the energy efficiency (EE) of an orthogo-nal frequency-division multiple access system with multiple trans-mit antennas supporting multiple single-receive-antenna users, we propose an EE-aware multiple access (EMA) scheme. The EMA selects an energy-efficient channel access method that is either time-division multiple access (TDMA) or space-division multiple access (SDMA) for each subband. For the SDMA, the near op-timal number of SDMA time slots is derived. Numerical results verify that the EE of pure TDMA and SDMA can be significantly improved through the proposed EMA scheme. Index Terms—Energy efficiency (EE), channel access method, multiple access method, time-division multiple access (TDMA), space-division multiple access (SDMA), orthogonal frequency-division multiple access (OFDMA). I.
Potential Games for Energy-Efficient Resource Allocation in Multipoint-toMultipoint CDMA
- Wireless Data Networks,” arXiv.org
, 2011
"... The problem of noncooperative resource allocation in a multipoint-to-multipoint cellular network is considered in this paper. The considered sce-nario is general enough to represent several key instances of modern wireless networks such as a multicellular network, a peer-to-peer network (interfer-en ..."
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Cited by 1 (0 self)
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The problem of noncooperative resource allocation in a multipoint-to-multipoint cellular network is considered in this paper. The considered sce-nario is general enough to represent several key instances of modern wireless networks such as a multicellular network, a peer-to-peer network (interfer-ence channel), and a wireless network equipped with femtocells. In partic-ular, the problem of joint transmit waveforms adaptation, linear receiver design, and transmit power control is examined. Several utility functions to be maximized are considered, and, among them, we cite the received SINR, and the transmitter energy efficiency, which is measured in bit/Joule, and represents the number of successfully delivered bits for each energy unit used for transmission. Resorting to the theory of potential games, noncoop-erative games admitting Nash equilibria in multipoint-to-multipoint cellu-lar networks regardless of the channel coefficient realizations are designed. Computer simulations confirm that the considered games are convergent, and show the huge benefits that resource allocation schemes can bring to the performance of wireless data networks. Keywords: Multicell networks, peer-to-peer networks, interference channel, femtocells, potential games, energy efficiency, waveform adaptation, power control. 1.
What Will 5G Be?
"... Abstract-What will 5G be? What it will not be is an incremental advance on 4G. The previous four generations of cellular technology have each been a major paradigm shift that has broken backward compatibility. Indeed, 5G will need to be a paradigm shift that includes very high carrier frequencies w ..."
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Abstract-What will 5G be? What it will not be is an incremental advance on 4G. The previous four generations of cellular technology have each been a major paradigm shift that has broken backward compatibility. Indeed, 5G will need to be a paradigm shift that includes very high carrier frequencies with massive bandwidths, extreme base station and device densities, and unprecedented numbers of antennas. However, unlike the previous four generations, it will also be highly integrative: tying any new 5G air interface and spectrum together with LTE and WiFi to provide universal high-rate coverage and a seamless user experience. To support this, the core network will also have to reach unprecedented levels of flexibility and intelligence, spectrum regulation will need to be rethought and improved, and energy and cost efficiencies will become even more critical considerations. This paper discusses all of these topics, identifying key challenges for future research and preliminary 5G standardization activities, while providing a comprehensive overview of the current literature, and in particular of the papers appearing in this special issue.
Spreading Code and Widely-Linear Receiver 1 Design: Non-Cooperative Games for Wireless CDMA Networks
, 2009
"... The issue of non-cooperative transceiver optimization in the uplink of a multiuser wireless code division multiple access data network with widely-linear detection at the receiver is considered. While previous work in this area has focused on a simple real signal model, in this paper a baseband comp ..."
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The issue of non-cooperative transceiver optimization in the uplink of a multiuser wireless code division multiple access data network with widely-linear detection at the receiver is considered. While previous work in this area has focused on a simple real signal model, in this paper a baseband complex representation of the data is used, so as to properly take into account the I and Q components of the received signal. For the case in which the received signal is improper, a widely-linear reception structure, processing separately the data and their complex conjugates, is considered. Several non-cooperative resource allocation games are considered for this new scenario, and the performance gains granted by the use of widely-linear detection are assessed through theoretical analysis. Numerical results confirm the validity of the theoretical findings, and show that exploiting the improper nature of the data in non-cooperative resource allocation brings remarkable performance improvements in multiuser wireless systems. Index Terms Widely-linear filtering, improper noise, multiuser detection, MMSE receiver, CDMA, power control, spreading code optimization, game theory, SINR maximization, MSE minimization, sum capacity, energy efficiency.
IEEE JSAC SPECIAL ISSUE ON 5G WIRELESS COMMUNICATION SYSTEMS 1 What Will 5G Be?
"... Abstract—What will 5G be? What it will not be is an in-cremental advance on 4G. The previous four generations of cellular technology have each been a major paradigm shift that has broken backwards compatibility. And indeed, 5G will need to be a paradigm shift that includes very high carrier frequenc ..."
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Abstract—What will 5G be? What it will not be is an in-cremental advance on 4G. The previous four generations of cellular technology have each been a major paradigm shift that has broken backwards compatibility. And indeed, 5G will need to be a paradigm shift that includes very high carrier frequencies with massive bandwidths, extreme base station and device densities and unprecedented numbers of antennas. But unlike the previous four generations, it will also be highly integrative: tying any new 5G air interface and spectrum together with LTE and WiFi to provide universal high-rate coverage and a seamless user experience. To support this, the core network will also have to reach unprecedented levels of flexibility and intelligence, spectrum regulation will need to be rethought and improved, and energy and cost efficiencies will become even more critical considerations. This paper discusses all of these topics, identifying key challenges for future research and preliminary 5G standardization activities, while providing a comprehensive overview of the current literature, and in particular of the papers appearing in this special issue. I.
