Patents by Inventor Chin Keong Ho

Chin Keong Ho has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20080187034
    Abstract: A method for equalizing a digital signal received via at least one communication channel is described, wherein a block of received signal values is processed by a block-iterative equalizer (200). The equalizer comprises a feedback unit (202) and a feed-forward unit (201) each corresponding to the multiplication by a respective matrix. The matrices are updated in the iterative process.
    Type: Application
    Filed: August 15, 2005
    Publication date: August 7, 2008
    Inventors: Ying Chang Liang, Sumei Sun, Chin Keong Ho
  • Publication number: 20080101499
    Abstract: A transmitter is described which has a determination unit for determining a plurality of symbols (301) such that each symbol (301) comprises a tail component (302) and the plurality is determined in such a way that the tail components (302) are substantially equal and a tone generation unit for arranging the plurality of symbols (301) to form a plurality of long preambles (300) such that the plurality of long preambles (300) are tone-interleaved.
    Type: Application
    Filed: August 13, 2005
    Publication date: May 1, 2008
    Inventors: Ho Wang Fung, Sumei Sun, Chin Keong Ho, Ying Chang Liang, Yan Wu
  • Publication number: 20080095262
    Abstract: A method for transmitting a digital signal is described, wherein the digital signal is to be transmitted by a plurality of antennas and a 2-domain pre-transformation is carried out, i.e., in course of a pre-transformation modulation symbols assigned to subcarriers having different frequencies and assigned to subcarriers sent by different antennas are linearly combined.
    Type: Application
    Filed: August 3, 2005
    Publication date: April 24, 2008
    Applicant: AGENCY FOR SCIENCE, TECHNOLOGY AND RESEARCH
    Inventors: Chin Keong Ho, Yan Wu, Sumei Sun, Zhongding Lei
  • Patent number: 7046744
    Abstract: A direct current (DC) offset estimation, frequency offset estimation, and compensation system (200), receives data packet (204) with preamble (206). A DC offset estimator (210) and a frequency offset estimator (212) operate concurrently to produce estimates of DC and frequency offsets of the data packet (204), which are determined from a portion of the preamble (206) as it is received. As the data packet (204) is received, a compensator (214) receives the estimates of DC and frequency offsets and compensates the remaining portion of the data packet (204) to produce a DC and frequency compensated data packet (218). Concurrent operation of the DC estimator (210) and the frequency offset estimator (212) advantageously allows more time to produce the estimates of DC and frequency offsets.
    Type: Grant
    Filed: March 15, 2002
    Date of Patent: May 16, 2006
    Assignee: Agency for Science, Technology and Research
    Inventors: Chin Keong Ho, Ping He, Sumei Sun
  • Patent number: 6990153
    Abstract: In a multi-channel communication system (300) data (306) and pilot data (308) are combined to provide a composite signal comprising discrete data signals (405), each having a data portion (407) and a pilot data portion (409). The composite signal is transmitted and a corresponding composite signal received on a communication channel having varying characteristics. An added pilot semi-blind (APSB) channel estimator (320) and equalizer (330) apply a converging iterative process to estimate the characteristics of the communication channel and the transmitted data.
    Type: Grant
    Filed: February 6, 2001
    Date of Patent: January 24, 2006
    Assignees: Agency for Science, Technology and Research, National University of Singapore
    Inventors: Behrouz Farhang-Boroujeni, Francois Po Shin Chin, Chin Keong Ho
  • Publication number: 20040005010
    Abstract: An initial estimate of the channel response in an OFDM system is obtained. An implied ICI is calculated using an estimated frequency offset, and used to adjust output from an FFT in an OFDM receiver. The channel response is iteratively estimated one or more times using this procedure. Data equalization is performed using the iteratively calculated channel estimate. The implied ICI is constructed, and the output from the FFT in the OFDM receiver is adjusted to determine an estimate of transmitted data. A simplified implementation of iterative channel estimation and data equalization involves adjusting single tap equalizer values to provide an acceptable estimate of incoming data. The simplified iterative channel equalizer can be implemented using a FIR filter.
    Type: Application
    Filed: July 5, 2002
    Publication date: January 8, 2004
    Applicant: National University of Singapore
    Inventors: Ping He, Chin Keong Ho, Sumei Sun
  • Publication number: 20030174790
    Abstract: A direct current (DC) offset estimation, frequency offset estimation, and compensation system (200), receives data packet (204) with preamble (206). A DC offset estimator (210) and a frequency offset estimator (212) operate concurrently to produce estimates of DC and frequency offsets of the data packet (204), which are determined from a portion of the preamble (206) as it is received. As the data packet (204) is received, a compensator (214) receives the estimates of DC and frequency offsets and compensates the remaining portion of the data packet (204) to produce a DC and frequency compensated data packet (218). Concurrent operation of the DC estimator (210) and the frequency offset estimator (212) advantageously allows more time to produce the estimates of DC and frequency offsets.
    Type: Application
    Filed: March 15, 2002
    Publication date: September 18, 2003
    Inventors: Chin Keong Ho, Ping He, Sumei Sun