TY - JOUR
T1 - Joint optimization of transmit power-time and bit energy efficiency in CDMA wireless sensor networks
AU - Shu, Tao
AU - Krunz, Marwan
AU - Vrudhula, Sarma
N1 - Funding Information:
Manuscript received November 16, 2004; revised October 16, 2005; accepted March 3, 2006. The associate editor coordinating the review of this paper and approving it for publication was Y. Yao. This work was supported in part by the National Science Foundation through grants ANI-0095626, ANI-0313234, and ANI-0325979; and in part by the Center for Low Power Electronics (CLPE) at the University of Arizona. CLPE is supported by NSF (grant EEC-9523338), the State of Arizona, and a consortium of industrial partners. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.
PY - 2006/11
Y1 - 2006/11
N2 - In this paper, we address the problem of minimizing energy consumption in a CDMA-based wireless sensor network (WSN). A comprehensive energy consumption model is proposed, which accounts for both the transmit and circuit energies. Energy consumption is minimized by jointly optimizing the transmit power and transmission time for each active node in the network. The problem is formulated as a non-convex optimization. Numerical as well as closed-form approximate solutions are provided. For the numerical solution, we show that the formulation can be transformed into a convex geometric programming (GP), for which fast algorithms, such as interior point method, can be applied. For the closed-form solution, we prove that the joint power/time optimization can be decoupled into two sequential sub-problems: optimization of transmit power with transmission time serving as a parameter, and then optimization of the transmission time. We show that the first sub-problem is a linear program while the second one can be well approximated as a convex programming problem. Taking advantage of these analytical results, we further derive the perbit energy efficiency. Our results are verified through numerical examples and simulations.
AB - In this paper, we address the problem of minimizing energy consumption in a CDMA-based wireless sensor network (WSN). A comprehensive energy consumption model is proposed, which accounts for both the transmit and circuit energies. Energy consumption is minimized by jointly optimizing the transmit power and transmission time for each active node in the network. The problem is formulated as a non-convex optimization. Numerical as well as closed-form approximate solutions are provided. For the numerical solution, we show that the formulation can be transformed into a convex geometric programming (GP), for which fast algorithms, such as interior point method, can be applied. For the closed-form solution, we prove that the joint power/time optimization can be decoupled into two sequential sub-problems: optimization of transmit power with transmission time serving as a parameter, and then optimization of the transmission time. We show that the first sub-problem is a linear program while the second one can be well approximated as a convex programming problem. Taking advantage of these analytical results, we further derive the perbit energy efficiency. Our results are verified through numerical examples and simulations.
KW - CDMA
KW - Convex optimization
KW - Geometric programming
KW - Joint power and time optimization
KW - Sensor network
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U2 - 10.1109/TWC.2006.04738
DO - 10.1109/TWC.2006.04738
M3 - Article
AN - SCOPUS:33846225651
SN - 1536-1276
VL - 5
SP - 3109
EP - 3118
JO - IEEE Transactions on Wireless Communications
JF - IEEE Transactions on Wireless Communications
IS - 11
ER -