Power-Efficient Distributed Estimation in Hybrid MAC Wireless Sensor Networks

In this paper, the distributed estimation of a deterministic scalar source by power-constrained wireless sensor networks with a fusion center is investigated over a hybrid multiple access channel Specifically, the maximum likelihood estimation is adopted, and the corresponding optimal and sub optimal schemes are developed to allocate sensor powers under a total power constraint. Particularly, a closed-form expression for sensor powers is obtained for suboptimal power allocation and a two-step procedure is proposed to solve the optimal power allocation problem numerically. It is analytically shown that the suboptimal power allocation scheme can offer asymptotically the same mean squared error performance as the optimal power allocation scheme when the number of sensors transmitting through the same coherent channel increases to infinity.