Approximation for a sum of on-off log-normal processes with wireless applications

The problem of maximizing a utility function while limiting the outage probability below an appropriate threshold is investigated. A coded-division multi access wireless network under mixed Nakagami-lognormal fading is considered. Solving such a utility maximization problem is difficult because the problem is non-convex and non-geometric with mixed integer and real decision variables and no explicit functions of the constraints are available. In this paper, three methods for the solution of the utility maximization problem are proposed. By the first method, a simple explicit outage approximation is used and the constraint that rates are integers is relaxed yielding a standard convex programming optimization that can be solved quickly but at the price of a reduced accuracy. The second method uses a more accurate outage approximation, which allows one solving the utility maximization problem by the Lagrange duality for non-convex problems and contraction mapping theory. The third method is a combination of the first and the second one. Numerical results show that the first method performs well for average values of the outage requirements, whereas the second one is always more accurate, but is also more computationally expensive. Finally, the third method gives same accuracy as the second one, but has a lower computational complexity only for a small number of transmitters.Index Terms-Radio power control, CDMA, outage, nonconvex optimization.

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“…and wherē (1) which, recalling the exponents of (26) and (27), implies that (2) (n, p) > (2) (n, p).…”

Section: Lemma 1: the Functionsmentioning

confidence: 92%

“…These expectations follows from distributive property of the expectation operator and can be easily derived as in [26].…”

Section: B Approximationmentioning

confidence: 99%

Utility Maximization via Power and Rate Allocation with Outage Constraints in Nakagami-Lognormal Channels

Fischione

d’Angelo

Butussi³

2011

IEEE Trans. Wireless Commun.

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“…Therefore, following the same approach as in [8], a moment-matching method can be applied and the denominator is well approximated with a log-normal random variable…”

Section: Symbolmentioning

confidence: 99%

How to Select the OOK Detection Threshold in Wireless Ad Hoc and Sensor Networks

d’Angelo

Fischione

2009

VTC Spring 2009 - IEEE 69th Vehicular Technology Conference

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On-off keying (OOK) is an attractive modulation technique to reduce energy consumption of power-constrained wireless networks. The OOK detection threshold, however, must be carefully selected to minimize the bit error probability (BER). This is a challenging task to accomplish on resource-limited nodes or on networks with high-mobility. In this paper, an efficient algorithm to compute the optimal threshold is proposed. The system scenario considers nodes simultaneously transmitting over same frequencies in Rayleigh-log-normal or Rice-log-normal fading conditions. It is shown that by using the Stirling expansion for the BER, and a log-normal approximation, a quick contractionmapping can be built to achieve the threshold numerically. The mapping is simple to implement and converges quickly. Numerical simulations verify the validity of the theoretical analysis, and show that the new algorithm performs quite well in scenarios of practical interest.

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“…Therefore, following the same approach as in [13], the Wilkinson's moment-matching method can be applied and the denominator is well approximated with a log-normal random variable σ 2…”

Section: Optimal Transmit Radio Powermentioning

confidence: 99%

Minimum Energy coding in CDMA Wireless Sensor Networks

Fischione

Johansson

Sangiovanni-Vincentelli

et al. 2009

IEEE Trans. Wireless Commun.

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A theoretical framework is proposed for accurate comparison of minimum energy coding in Coded Division Multiple Access (CDMA) Wireless Sensor Networks (WSNs). Energy consumption and reliability are analyzed for two coding schemes: Minimum Energy coding (ME), and Modified Minimum Energy coding (MME). A detailed model of consumed energy is described as function of the coding, radio transmit power, the characteristics of the transceivers, and the dynamics of the wireless channel. Since CDMA is strongly limited by multi-access interference, the system model includes all the relevant characteristics of wireless propagation. A distributed and asynchronous algorithm, which minimizes the total energy consumption by controlling the radio power, is developed. Numerical results are presented to validate the theoretical analysis and show under which conditions MME outperforms ME with respect to energy consumption and bit error rate. It is concluded that MME is more energy efficient than ME only for short codewords.Index Terms-Wireless sensor network (WSNs), minimum energy coding, CDMA, OOK, power control, outages, parallel and distributed computation.

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Approximation for a sum of on-off log-normal processes with wireless applications

Cited by 10 publications

References 18 publications

Utility Maximization via Power and Rate Allocation with Outage Constraints in Nakagami-Lognormal Channels

Utility Maximization via Power and Rate Allocation with Outage Constraints in Nakagami-Lognormal Channels

How to Select the OOK Detection Threshold in Wireless Ad Hoc and Sensor Networks

Minimum Energy coding in CDMA Wireless Sensor Networks

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