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26
BAn energyefficient approach to power control and receiver design in wireless data networks,[
 IEEE Trans. Commun.,
, 2005
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An Analytical Foundation for Resource Management in Wireless Communication
, 2003
"... The maximization of a ratio of the form f(x)/x, with f some "Scurve", plays a central role in several important problems involving resource management for data communication over a wireless medium. This includes decentralized power control, power and data rate assignment for maximal netwo ..."
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Cited by 33 (10 self)
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The maximization of a ratio of the form f(x)/x, with f some "Scurve", plays a central role in several important problems involving resource management for data communication over a wireless medium. This includes decentralized power control, power and data rate assignment for maximal network throughput in a 3GCDMA context, and power and coding rate choice for multimedia files which have been scalably encoded, as with the JPEG2000 and MPEG4 standards. In this note, the ratio f(x)/x, where f is a realvalued, univariate "sshaped" function, is shown to be quasiconcave, and to always have a unique global maximizer, which can be identified graphically. The analysis is strictly based on geometrical properties derived from the sigmoidal shape, imposing no specific algebraic functional form ("equation") on the function. Hence, it applies to a wide range of practical situations.
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.
MarketDriven Dynamic Spectrum Allocation: Optimal EndUser Pricing and Admission Control for CDMA
 Proc. of 14th IST Mobile & Wireless Communications
, 2005
"... Abstract — Dynamic spectrum allocation (DSA) seeks to exploit the variations in the loads of various radioaccess networks to allocate the spectrum efficiently. Previous work studies a centralised scheme in which a spectrum manager periodically reallocates spectrum without business considerations ..."
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Cited by 13 (3 self)
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Abstract — Dynamic spectrum allocation (DSA) seeks to exploit the variations in the loads of various radioaccess networks to allocate the spectrum efficiently. Previous work studies a centralised scheme in which a spectrum manager periodically reallocates spectrum without business considerations. In the present scheme, a spectrum manager performs DSA by periodically selling to network operators shortterm spectrum licenses. We target a CDMAbased radioaccess technology, and delaytolerant data applications of various data rates, on the downlink. We solve analytically the problem of the network operator, which must decide simultaneously how much spectrum to purchase, and how to charge its own utilitymaximising customers in a way that encourages efficient usage, and maximises the operator’s profit. We identify a specific operating point consistent with the interests of both the operator and its customers. With linear spectrum costs, and convenient units of measurement, the operator declines to serve a terminal when a product of known parameters is less than one. I.
Auction driven dynamic spectrum allocation: optimal bidding, pricing and service priorities for multirate, multiclass CDMA
 IEEE 16th International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC
"... Abstract — Dynamic spectrum allocation (DSA) seeks to exploit the variations in the loads of various radioaccess networks to allocate the spectrum efficiently. Here, a spectrum manager implements DSA by periodically auctioning shortterm spectrum licenses. We solve analytically the problem of the ..."
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Cited by 13 (2 self)
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Abstract — Dynamic spectrum allocation (DSA) seeks to exploit the variations in the loads of various radioaccess networks to allocate the spectrum efficiently. Here, a spectrum manager implements DSA by periodically auctioning shortterm spectrum licenses. We solve analytically the problem of the operator of a CDMA cell populated by delaytolerant terminals operating at various data rates, on the downlink, and representing users with dissimilar “willingness to pay ” (WtP). WtP is the most a user would pay for a correctly transferred information bit. The operator finds a revenuemaximising internal pricing and a service priority policy, along with a bid for spectrum. Our clear and specific analytical results apply to a wide variety of physical layer configurations. The optimal operating point can be easily obtained from the framesuccess rate function. At the optimum, (with a convenient time scale) a terminal’s contribution to revenues is the product of its WtP by its data rate; and the product of its WtP by its channel gain determines its service priority ("revenue per Hertz"). Assuming a secondprice auction, the operator’s optimal bid for a certain spectrum band equals the sum of the individual revenue contributions of the additional terminals that could be served, if the band is won. I.
Resource Management for Scalably Encoded Information: The Case of Image Transmission over Wireless Networks
, 2003
"... Scalable encoded information, as in the JPEG 2000 standard, results in files which can be truncated at an arbitrary point and decoded. This work introduces a tractable, yet flexible model appropriate for resource management involving scalably encoded information. At its core is a function yielding a ..."
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Cited by 8 (4 self)
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Scalable encoded information, as in the JPEG 2000 standard, results in files which can be truncated at an arbitrary point and decoded. This work introduces a tractable, yet flexible model appropriate for resource management involving scalably encoded information. At its core is a function yielding a measure of "quality" of the decoded information as a function of the number of bits chosen for decoding. It is assumed that all that is known about this function is that its graph yields an "Scurve". An energyefficient policy for the transmission over a wireless network of scalablyencoded images is sought. Two variables are jointly optimized: transmission power, and the number of bits of each file to be decoded ("coding rate"). The singleuser case is fully analyzed, and a closedform solution given, which can be clearly identified, graphically. The analysis indicates that both variables can be "decoupled", and their optimal values found independently of each other.
Maximizing the throughput of CDMA data communications
 IEEE VTC, Orlando FL, Oct 69
"... Abstract—We analyze aggregate throughput as a function of the transmitter power levels and the number of terminals sending data to a CDMA base station. We find that when noise and outofcell interference are negligible, received power balancing maximizes the aggregate throughout of the base station, ..."
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Cited by 5 (4 self)
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Abstract—We analyze aggregate throughput as a function of the transmitter power levels and the number of terminals sending data to a CDMA base station. We find that when noise and outofcell interference are negligible, received power balancing maximizes the aggregate throughout of the base station, provided the population of active terminals does not exceed an optimum size. The optimum number of active terminals depends on the CDMA processing gain and the details of the physical layer and data link layer. These details are summarized in a univariate frame success function. When noise is present, power balancing is suboptimal mathematically but attractive for practical implementation. Keywordspower control; radio resources management; power balancing I.
Optimal Coding Rate and Power Allocation for the Streaming of Scalably Encoded Video over a Wireless Link
"... Scalably encoded information results in files which can be truncated at an arbitrary point and decoded, as supported by the JPEG2000 (image) and MPEG4 (video) standards. This work introduces a tractable, yet flexible analytical model for resource management involving scalably encoded video. Each ..."
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Cited by 5 (2 self)
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Scalably encoded information results in files which can be truncated at an arbitrary point and decoded, as supported by the JPEG2000 (image) and MPEG4 (video) standards. This work introduces a tractable, yet flexible analytical model for resource management involving scalably encoded video. Each segment of video of a predetermined length yields a file that can be truncated and decoded independently of other segments. The problem is set up as a joint optimization of transmission power, and coding rate (where to truncate ?). The analysis reveals that any one of these variables uniquely determines the other. The terminal should truncate the file at the point that maximizes quality per unit of power employed.
A Gametheoretic Analysis of Link Adaptation in Cellular Radio Networks
, 2004
"... In recent years, game theory has emerged as a promising approach to solving the power control problem in wireless networks. This thesis extends the reach of gametheoretic analysis to embrace link adaptation, thereby constituting a generalization of the power control problem. A realistic and natural ..."
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Cited by 3 (1 self)
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In recent years, game theory has emerged as a promising approach to solving the power control problem in wireless networks. This thesis extends the reach of gametheoretic analysis to embrace link adaptation, thereby constituting a generalization of the power control problem. A realistic and natural problem formulation is attempted, wherein transmitter power and a discretevalued Adaptable Link Parameter (ALP), e.g. code rate, constitute the action set of a player in this game. The dual goals of maximizing throughput and minimizing power consumption are reflected in the utility function selection, which uses the accurate sigmoid model for approximating throughput. The discrete action space makes it difficult to verify the existence of a Nash Equilibrium (NE) in this game using standard techniques. To circumvent this limitation, a heuristic algorithm is proposed. This algorithm is analytically shown to always converge to a NE. The subsequent results probe its validity and sensitivity. Favorable comparisons are drawn between these gametheoretic results and those arising from parallel systems techniques. A linear programming system optimization that exploits properties of the
Power and Data Rate Assignment for Maximal Weighted Throughput in 3G CDMA
, 2003
"... Relevant to the uplink of a VSGCDMA system, a technique part of 3G standards, this work seeks power and data rate allocations for each of N terminals, so that the network weighted throughput is maximized. The weights admit various interpretations, including levels of importance, "utility" ..."
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Cited by 3 (3 self)
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Relevant to the uplink of a VSGCDMA system, a technique part of 3G standards, this work seeks power and data rate allocations for each of N terminals, so that the network weighted throughput is maximized. The weights admit various interpretations, including levels of importance, "utility", and price. We have learned that at least one terminal should operate at the highest available data rate. Our analysis leads to allocations in which terminals not operating at the highest data rate operate at the same signaltointerference ratio (SIR). This value is determined by the physical layer through the function that gives, in terms of the received SIR, the probability that a data packet is received correctly. Other factors held constant, lowering the highest available data rate increases the number of terminals which should operate at maximum data rate. This analysis conforms to classical optimization theory. Our model should accommodate a wide variety of physical layer configurations.