Power Adaptation in Multi-hop Sensor Networks for Energy Minimization

The power adaptation issue for multi-hop sensor networks is considered in this paper to minimize the energy consumption with a given requirement of the average end-to-end bit error rate (BER) performance. To optimize the power adaptation, a nonlinear programming problem is formulated and an analytical result is derived from its Karush-Kuhb-Tucker (KKT) necessary conditions. Numerical examples are presented to compare the networks with the proposed power adaptation scheme and a distributed power adaptation scheme, in which the transmitter of each individual hop adjusts its transmission power based on its own channel state information (CSI) and a specified BER requirement for this hop. A significant energy saving is achieved with the use of the proposed scheme.