Electrical Engineering
      and Computer Sciences

Electrical Engineering and Computer Sciences


UC Berkeley


2008 Research Summary

Collaborative Communication for Cognitive Radio Applications

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Ben Juda Wild and Kannan Ramchandran

It is well known that wireless spectrum is vastly under-utilized. In our previous work, we attempted to re-use spectrum by dynamically sensing receivers, and re-using bands where no receivers were tuned to [1]. Currently, our focus has shifted to using collaborative beamforming among cognitive radios to use the spatial dimension efficiently [2]. In [2] we describe the world's first experimental distributed beamforming testbed. Using this testbed, we have shown that N collaborating radios can in fact achieve beamforming gains proportional to N2.

B. Wild and K. Ramchandran, "Detecting Primary Receivers for Cognitive Radio Applications," Proc. Dynamic Spectrum Access Networks, November 2005.
R. Mudumbai, B. Wild, U. Madhow, and K. Ramchandran, "Distributed Beamforming Using 1 Bit Feedback: from Concept to Realization," Proc. Allerton Conf. Communication, Control and Computing, September 2006.