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HBBCL Wi-Fi Effort
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Overview of Wi-Fi Work at Harvard:
Currently, we are witnessing a rapid growth in Wi-Fi market penetration.
This in turn will change the wireless landscape by the end of this decade.
In residential environments, short range nomadic wireless data using wireless
LANs can be provided inexpensively and this will be adequate. In commercial
environments, networking short range Wi-Fi devices can be very costly because
of the installation and networking expenses. In hot spots, there will be
a large number of nomadic users demanding high data rates. Thus, we must
solve both the problems of increasing demand for high data rates and
the range of Wi-Fi devices This motivates our Wi-Fi research at Harvard.
Our activities in this field are summarized below:
Enhancements to Existing Wi-Fi Systems Using Beamforming/SDMA
In order to increase the range/capacity of existing Wi-Fi systems, we have
considered the applications of antenna arrays in conjunction with Beamforming/SDMA
at tha Access Point (AP). This solution is particularly appealing because
it is backward compatible. Many issues arise that must be resolved in order
to obtain the available gains from combining SDMA with Wi-Fi standard.
When beamforming is employed to increase the range of CSMA systems, then
the hidden beam problem may arise. To this end, an HBBCL researcher
has invented (jointly with Vivato R&D researchers S.M. Alamouti and
Y.S. Choi) the concept of complementary
beamforming .
Space-Time Coding for Wi-Fi Enhancements
HBBCL researchers are considering space-time coding for enhancing future
generations of Wi-Fi systems. This of course requires changes to the existing
standards. Space-time code design to achieve the capacity gains
of multiple antenna Wi-Fi systems is a challenging problem, because the
designed codes must be extremely simple and efficient to reduce both the
costs and power requirements. Please see our research web page on space-time
codes for additional information.
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