Power allocation for distributed estimation in sensor networks with semi-orthogonal MAC

This paper is concerned with distributed estimation in a Gaussian sensor network under the semi-orthogonal multiple access channel (MAC). Under the total transmit power constraint, an improved power allocation scheme among sensors is investigated. In the semi-orthogonal MAC, since sensors are divided into groups, the issue of power allocation can be separated into two tasks: power allocation within each sensor group and power allocation among sensor groups. In this paper, both tasks are studied and solutions are provided. Simulation results show that the improved power allocation can provide much better average mean squared error (MSE) performance than equal power allocation, especially at low channel signal-to-noise ratio.