Patents Assigned to National Univ. of Singapore
  • Patent number: 7167526
    Abstract: A method and apparatus for achieving combined beamforming and transmit diversity for frequency selective fading channels in a communication system having a base station with multiple transmit antennae and a mobile terminal with at least a single receive antenna, the method comprising the steps of: providing a signal to be transmitted; space-time encoding the signal to produce at least two separate signals, each on a respective output; feeding each output signal to a multiple access transmit processor to produce an output signal; applying respective selected transmit beamforming weights to each output signal; feeding the respective weighted signals to a signal combiner to perform a summing function of the signals and produce a signal for transmission; feeding the summed signal to each of the multiple transmit antennae for transmission; transmitting the signals over respective physical channels; receiving the transmitted signal at at least a single receive antenna; feeding the transmitted signal to a multiple a
    Type: Grant
    Filed: January 18, 2002
    Date of Patent: January 23, 2007
    Assignee: National Univ. of Singapore
    Inventors: Ying-Chang Liang, Francois Po Shin Chin
  • Patent number: 6438161
    Abstract: A method of designing an equalizer having a target response suited to a particular subclass of communication channels to shorten the duration of the impulse response of the overall transmission system, a class of channels being divided into a number of subclasses, each subclass having a fixed set of parameters selected to achieve the target response of the equalizer for that particular subclass of channel, the method comprising the steps of recognizing the subclass of the channel; and identifying the fixed set of parameters for the equaliser to achieve the target response by reference to a look-up table based on the subclass of the channel.
    Type: Grant
    Filed: September 28, 1999
    Date of Patent: August 20, 2002
    Assignee: National Univ. of Singapore
    Inventors: Behrouz Farhang-Boroujeny, Baoli Wang, Mrityunjoy Chakraborty
  • Patent number: 6121130
    Abstract: A process for curing low-k spin-on dielectric layers based on alkyl silsesquioxane polymers by laser scanning is described wherein curing is achieved by both photothermal and photochemical mechanisms. The layers are deposited by spin deposition, dried and cured by raster scanning with a pulsed laser at energies between 0.1 and 1 Joules/cm.sup.2. Because the laser causes heating of the layer, a nitrogen jet is applied in the wake of the scanning laser beam to rapidly cool the layer and to inhibit oxidation and moisture absorption. The laser induced heating also assists in the discharge of moisture and by-products of the polymerization process. The laser operates at wavelengths between 200 and 400 nm. Insulative layers such as silicon oxide are sufficiently transparent at these so that oxide segments overlying the polymer layer do not inhibit the curing process. Implementation of the laser scanning feature is readily incorporated into an existing spin-on deposition and curing tool.
    Type: Grant
    Filed: November 16, 1998
    Date of Patent: September 19, 2000
    Assignees: Chartered Semiconductor Manufacturing Ltd., National Univ. of Singapore, Nanyang Technology Univ.
    Inventors: Chee Tee Chua, Yuan-Ping Lee, Mei Sheng Zhou, Lap Chan