Issue No 8: May 2004
New round of funding approved
Nine projects awarded $27.5m
Q&A: Peer-review policy kept under constant review
‘Simple’ solution to reducing data flow bottlenecks
New use for common laser diode provides key for all-optical network
Design ideas bring smart antenna down to size and with less radiation
Algorithm leads to boost in performance
Filter contributes to success of two-way global positioning system
Mobile phone circuits to get even smaller

Smart antennas allow narrow beams to be directed to a subscriber while supressing interference
As mobile phone technology moves towards 3G (Third Generation) with data flow speeds about 200 times faster than 2G, a research project at HKUST has formulated an algorithm that helps in the optimisation of signal performance.
3G employs CDMA (Code Division Multi Access) technology which allows many users to share the same bandwidth simultaneously. Users are each allocated a unique code which enables them to extract their own signal. Theoretically there should be no signal interference. In reality with thousands of users, says Principal Investigator Prof Khaled Ben Letaief, interference can be a serious problem. As a solution, the researchers considered the use of MIMO technology where smart antennas are combined with advanced temporal processing.
Different configurations of multiple antennas were considered. Because of cost, especially attractive was the use of multiple antennas at the base station and the simplest possible mobile receivers.
Applying new techniques, the researchers devised advanced architectures with the corresponding signal processing algorithm. “Results show a huge increase in system performance,” said Prof Letaief.

Principal Investigator
Prof Khaled Ben Letaief :