Lifetime Maximization for Joint Estimation in Wireless Sensor Networks

We consider the lifetime maximization problem for joint estimation in wireless sensor network. In the joint estimation problem, each sensor observes a noise-corrupted version of a physical quantity, then amplifies and forwards the observation to the destination (fusion center) through a wireless channel. The fusion center combines the data and constructs a joint estimate. The sensors may communicate with the destination through either orthogonal or shared channels. We develop algorithms that jointly determine the transmit power of sensors as a function of sensor measurement noises, wireless channel coefficients, and the available battery power at sensors. The objective of the algorithm is to maximize the lifetime of the network, while a certain quality of estimation at the fusion center is maintained throughout the lifetime of the network. It is observed that the present algorithm behaves differently compared to minimum- transmit-power strategies, and performs better in terms of the longevity of the network.