Patents by Inventor Dong-Woon Bai

Dong-Woon Bai 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).

  • Diversity transmitter-receiver in CDMA system using space-time code, and method thereof
    Patent number: 7769077
    Abstract: A diversity transmitting/receiving apparatus and method is provided, which is implemented using space-time trellis codes (STTC) constructed from a Pseudo Noise (PN) sequence set in a Direct Sequence (DS) CDMA system. The transmitter comprises a PN sequence generator, a space-time encoder, first and second modulators, and first and second multiple transmit antennas. The space-time encoder selects two of the multiple PN sequences to construct STTC, and space-time encodes data from a data source according to the STTC to output an Wary data symbol. The two modulators modulate the space-time encoded data according to the STTC. The two multiple transmit antennas wirelessly transmit outputs of the two modulators, respectively. By applying a method using space-time coding in a DS CDMA system including multiple transmit antennas, it is possible to achieve both diversity and additional coding gain and also to reduce multiple user interference by increasing the PN sequence length.
    Type: Grant
    Filed: December 21, 2004
    Date of Patent: August 3, 2010
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Dong-Woon Bai, Woo-Yong Lee, Hyun-Seo Oh
  • Diversity transmitter-receiver in cdma system using space-time code, and method thereof
    Publication number: 20090207890
    Abstract: A diversity transmitting/receiving apparatus and method is provided, which is implemented using space-time trellis codes (STTC) constructed from a Pseudo Noise (PN) sequence set in a Direct Sequence (DS) CDMA system. The transmitter comprises a PN sequence generator, a space-time encoder, first and second modulators, and first and second multiple transmit antennas. The space-time encoder selects two of the multiple PN sequences to construct STTC, and space-time encodes data from a data source according to the STTC to output an Wary data symbol. The two modulators modulate the space-time encoded data according to the STTC. The two multiple transmit antennas wirelessly transmit outputs of the two modulators, respectively. By applying a method using space-time coding in a DS CDMA system including multiple transmit antennas, it is possible to achieve both diversity and additional coding gain and also to reduce multiple user interference by increasing the PN sequence length.
    Type: Application
    Filed: December 21, 2004
    Publication date: August 20, 2009
    Inventors: Dong-Woon Bai, Woo-Yong Lee, Hyun-Seo Oh