On Scaling Laws of Diversity Schemes in Decentralized Estimation

This paper is concerned with decentralized estimation of a Gaussian source using multiple sensors. We consider a diversity scheme where only the sensor with the best channel sends their measurements over a fading channel to a fusion center, using the analog amplify and forwarding technique. The fusion centre reconstructs a minimum mean squared error (MMSE) estimate of the source based on the received measurements. A distributed version of the diversity scheme where sensors decide whether to transmit based only on their local channel information is also considered. We derive asymptotic expressions for the expected distortion (of the MMSE estimate at the fusion centre) of these schemes as the number of sensors becomes large. For comparison, asymptotic expressions for the expected distortion for a coherent multi-access scheme and an orthogonal access scheme are derived. It is seen that as opposed to the coherent multi-access scheme and the orthogonal scheme (where the expected distortion...

• Type: Journal
• Year: 2010
• Where: CORR
• Authors: Alex S. Leong, Subhrakanti Dey
• Keywords: CORR 2010, Distortion, Education, Power Allocation, Sensor