Systems Seminar
A Virtual MIMO Framework for Exploiting the Degrees of Freedom in
Multipath Fading Channels
Ashwin Ganesan
UW ECE Dept.
Abstract
Multipath fading is an important factor limiting the performance of mobile
wireless communication systems. An understanding of the interaction
between the signal space and the channel is fundamental to reliable
communication. For any transceiver structure, there are two key
factors that affect system performance: the number of parallel
channels created by the signaling scheme and the level of diversity
afforded by the channel. We present a virtual MIMO (multiple-input
multiple-output) framework for representing single-transmitter
single-receiver multipath channels that clearly reveals the affect
of the two factors and facilitates transceiver design to attain
capacity. We arrive at four different MIMO channel models depending
on the basis functions used to characterize the signal space dimensions.
Specific transceiver structures are represented by special cases of
the MIMO models. The framework makes it possible to derive closed
form expressions for ergodic and outage capacity for a variety of
transceivers. We also present a simple transceiver for transforming
the temporal multipath channel into a virtual multiple antenna array
system to which recently developed space-time codes can be directly
applied.
Time and Place: Wed., Nov. 8, Noon-1:00 pm in 2239 Engr. Hall.
SYSTEMS SEMINAR WEB PAGE:
http://www.cae.wisc.edu/~gubner/seminar/