1Corporate Research and Development, Qualcomm Incorporated, San Diego, California
2State University of New York, Department of Electrical Engineering, Buffalo, New York
3University of Maryland, Department of Electrical and Computer Engineering, College Park, Maryland
The unprecedented improvements shown by electronic devices in terms of computing power per unit area, communication capacity, and energy efficiency are fueling the increased pervasiveness of networks of a large number of small devices that collaborate in a distributed fashion to perform some functions. Among this type of networks, the dense sensor network presents unique characteristics and research problems. Of these, this chapter focuses on the inherent limited energy available to the component nodes and of the possibility of the nodes cooperating during both sensing and communication. One of the most severe impairments to wireless communications is channel fading. Fading causes a significant loss in the transmitted power compared to the benign additive white Gaussian noise (AWGN) channel because, when the signal experiences a deep fade, the receiver can not decode it. A widely used technique to combat the effects of channel fading is diversity. Spatial diversity achieved through multiple antennas installed ...