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 : eekhaled@ee.ust.hk