Systems Seminar
Cognitive Wireless Communication and Sensing in Time, Frequency, and Space
Akbar Sayeed
UW ECE Department
Abstract
Multipath signal propagation, a salient feature of wireless channels, results
in detrimental signal fading and yet it is also a key source of diversity to
combat fading and to increase the capacity and reliability of wireless
communication systems. Technological advances in reconfigurable RF front-ends
and antenna arrays are enabling new modes for sensing and adapting to
multipath in time, frequency, and space. However, the current understanding
of the design and fundamental performance limits of such cognitive wireless
systems is still in its infancy. One emerging insight is that physical
channels exhibit a sparse multipath structure as the dimension of the
spatio-temporal signal space increases. I will present three examples of
exploiting multipath sparsity with reconfigurable transceivers.
First, I will discuss the impact of signaling duration and bandwidth on
channel learning, capacity and reliability in the wideband/low-SNR regime.
Second, I will discuss the adaptation of array configurations for maximizing
capacity as a function of operating SNR. Finally, I will present results on
a distributed communication architecture -- Active Wireless Sensing -- in
which an access point equipped with an antenna array interrogates an
ensemble of wireless sensor nodes with wideband space-time waveforms for
rapid retrieval of sensor information.
Time and Place: Wed., Mar. 14, at 3:30 pm in 4610 Engr. Hall.
SYSTEMS SEMINAR WEB PAGE:
http://homepages.cae.wisc.edu/~gubner/seminar/schedule.html