---- dataentry seminar ----
date_dt : 2006-05-05
title : Cooperative wireless networks
speaker : Dr Frederique Oggier
affiliation :  Caltech
time : 
room : 
table : seminars
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template:datatemplates:seminar
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==== abstract ====
Recently, attention has been focused on wireless networks. 
Methods to exploit diversity using the antennas of different
users in a cooperative way have been studied, in order to look
for the diversity known to be achieved in the multiple antennas
point to point case. We consider a wireless network where a
transmitter and a receiver are distinguished, with enough
computational capacity and power to encode/decode the data, 
and use several antennas to transmit/receive the signal. 
The other nodes are relays, small devices with few power and 
computational ability, with only one antenna (as for example in 
sensor networks). In this scenario, it is not realistic to assume 
nodes can decode the information. We thus propose a strategy 
based on the idea of Distributed Space-Time Coding, where the 
nodes just do a very simple operation before forwarding the information. 
Our scheme relies on known algebraic Space-Time Codes. It is suitable for
 any number of transmit/receive antennas and nodes. It is shown to perform 
better than random codes, with less encoding complexity. We also briefly 
discuss the scenario where nodes may be down in the network, and show 
that our strategy is resistant to node failures.

{{:en:group:seminars:frederique1104.pdf|Full presentation}}