Patents by Inventor Won-Joon Choi

Won-Joon Choi 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: 20130100885
    Abstract: Methods and apparatus for selectively invoking receive diversity during power-up/initial acquisition and out of service modes are disclosed. A method can include selectively enabling receive diversity based on an initial acquisition attempt by one of the receive chains in a wireless device having multiple receive chains. A method can also include enabling receive diversity based on a predetermined list of channels to be acquired. A predetermined list of channels is a subset of a plurality of channels that may be acquired. Other aspects, embodiments, and features are also claimed and described.
    Type: Application
    Filed: October 2, 2012
    Publication date: April 25, 2013
    Applicant: Qualcomm Incorporated
    Inventors: Francis Ming-Meng Ngai, Rashad Ahmed Akbar Attar, Won Joon Choi, Stanley Tsai, Insung Kang, Jing Sun, Amir Dabbagh
  • Publication number: 20130033927
    Abstract: A magnetic resistance memory apparatus capable of implementing various levels and a method of driving the same are provided. The magnetic resistance memory apparatus includes a first magnetic device that includes a fixed layer having a fixed magnetization direction, a tunnel layer disposed on the fixed layer, and a first free layer disposed on the tunnel layer having a variable magnetization direction, and a second magnetic device disposed on the first magnetic device including a plurality of free layers insulated with a spacer layer interposed.
    Type: Application
    Filed: September 23, 2011
    Publication date: February 7, 2013
    Inventor: Won Joon CHOI
  • Publication number: 20130017625
    Abstract: In a method for fabricating a magnetic tunnel junction, a first magnetic layer is formed on a substrate, and a tunnel insulating layer is formed on the first magnetic layer. Subsequently, a second magnetic layer is formed on the tunnel insulating layer. In the method, the first magnetic layer is formed by periodically sputtering a magnetic target while a metal target is continuously sputtered.
    Type: Application
    Filed: December 23, 2011
    Publication date: January 17, 2013
    Inventor: Won Joon CHOI
  • Publication number: 20130015539
    Abstract: A magnetic memory device capable of ensuring a constant TMR difference even when the margin in a thickness of a magnetic layer constituting a KO is small is provided. The magnetic memory device includes a first magnetic layer having a fixed magnetization direction, a magnetization fixing layer formed on the first magnetic layer, a tunnel barrier layer formed on the magnetization fixing layer, and a second magnetic layer formed on the tunnel barrier layer and having a changeable magnetization direction.
    Type: Application
    Filed: September 22, 2011
    Publication date: January 17, 2013
    Inventor: Won Joon CHOI
  • Publication number: 20130015540
    Abstract: A magnetic tunnel junction device includes a first electrode having a curved top surface, a magnetic tunnel junction layer formed along the top surface of the first electrode, and a second electrode formed on the magnetic tunnel junction layer.
    Type: Application
    Filed: December 23, 2011
    Publication date: January 17, 2013
    Inventor: Won Joon CHOI
  • Patent number: 8331149
    Abstract: A 3D nonvolatile memory device includes: a plurality of channel structures including a plurality of channel layers and interlayer dielectric layers, which are alternately stacked, and extended in a first direction; a plurality of word lines extended in a second direction at least substantially perpendicular to the first direction; a plurality of row select lines connected to the plurality of channel layers, respectively, and extended in the second direction; and a plurality of column select lines connected to the plurality of channel structures, respectively, and extended in the first direction.
    Type: Grant
    Filed: May 18, 2010
    Date of Patent: December 11, 2012
    Assignee: Hynix Semiconductor, Inc.
    Inventors: Won-Joon Choi, Moon-Sig Joo, Ki-Hong Lee, Beom-Yong Kim, Jun-Yeol Cho, Young-Wook Lee
  • Patent number: 8295380
    Abstract: An automatic gain control (AGC) circuit and method for performing AGC for an orthogonal frequency-division multiplexing (OFDM) receiver measures signal power of input digital signals that are derived from incoming data frames with preambles to produce gain change signals when the signal power differs from a reference target power level. The gain of an amplifier of the OFDM receiver is changed in response to the gain change signals until a preamble of the data frames is detected for the first time. The gain of the amplifier of the OFDM receiver is further changed in response to the gain change signals, after the preamble is detected, only during periods when the preambles of the data frames are being processed by the OFDM receiver such that the gain of the amplifier is not changed during periods when other portions of the data frames are being processed by the OFDM receiver.
    Type: Grant
    Filed: May 5, 2008
    Date of Patent: October 23, 2012
    Assignee: Amicus Wireless Technology Ltd
    Inventors: Mingrui Zhu, Gwang-Hyun Gho, Won-Joon Choi
  • Patent number: 8270528
    Abstract: Techniques are disclosed for detecting a packet. One technique includes sampling a received signal to produce a sequence of samples wherein the sequence of samples includes a plurality of subsequences of samples; cross correlating the subsequences of samples with a known form of the subsequence to produce cross correlations; self correlating the cross correlations to produce a plurality of self correlations; summing the self correlations; and processing the sum of the self correlations.
    Type: Grant
    Filed: May 21, 2010
    Date of Patent: September 18, 2012
    Assignee: Qualcomm Atheros, Inc.
    Inventors: Chaohuang Zeng, Jeffrey M. Gilbert, Won-Joon Choi, Xiaoru Zhang
  • Publication number: 20120211822
    Abstract: A method for fabricating a non-volatile memory device includes alternately stacking a plurality of interlayer dielectric layers and a plurality of conductive layers over a substrate, etching the interlayer dielectric layers and the conductive layers to form a trench which exposes a surface of the substrate forming a first material layer over a resulting structure in which the trench is formed, forming a second material layer over the first material layer, removing portions of the second material layer and the first material layer formed on a bottom of the trench to expose the surface of the substrate, removing the second material layer, and burying a channel layer within the trench in which the second material layer is removed.
    Type: Application
    Filed: May 2, 2012
    Publication date: August 23, 2012
    Inventors: Se-Yun Lim, Eun-Seok Choi, Young-Wook Lee, Won-Joon Choi, Ki-Hong Lee, Sang-Bum Lee
  • Patent number: 8241974
    Abstract: A nonvolatile memory device with a blocking layer controlling the transfer of electric charges in a charge storage layer includes the blocking layer having a first blocking layer in contact with the charge storage layer and a second blocking layer over the first blocking layer, wherein the first blocking layer has a greater energy band gap than the second blocking layer and the second blocking layer has a greater permittivity than the first blocking layer.
    Type: Grant
    Filed: June 22, 2011
    Date of Patent: August 14, 2012
    Assignee: Hynix Semiconductor Inc.
    Inventors: Heung-Jae Cho, Moon-Sig Joo, Yong-Soo Kim, Won-Joon Choi
  • Patent number: 8187938
    Abstract: A method for fabricating a non-volatile memory device includes alternately stacking a plurality of interlayer dielectric layers and a plurality of conductive layers over a substrate, etching the interlayer dielectric layers and the conductive layers to form a trench which exposes a surface of the substrate forming a first material layer over a resulting structure in which the trench is formed, forming a second material layer over the first material layer, removing portions of the second material layer and the first material layer formed on a bottom of the trench to expose the surface of the substrate, removing the second material layer, and burying a channel layer within the trench in which the second material layer is removed.
    Type: Grant
    Filed: April 5, 2010
    Date of Patent: May 29, 2012
    Assignee: Hynix Semiconductor Inc.
    Inventors: Se-Yun Lim, Eun-Seok Choi, Young-Wook Lee, Won-Joon Choi, Ki-Hong Lee, Sang-Bum Lee
  • Patent number: 8184754
    Abstract: Spurs cause significant problems with signal detecting, amplifier gain adjustment, and signal decoding. Various techniques can be used to mitigate the effects of spurs on a received signal. Generally, these techniques work by either canceling or ignoring the spurs. For example, a pilot mask can be used to ignore pilot information in one or more sub-channels. A Viterbi mask can determine the weighting given to bits in a sub-channel based on spur and data rate information. Channel interpolation can compute a pseudo channel estimate for a sub-channel known to have a spur location can be computed by interpolating the channel estimates of adjacent good sub-channels. Filtering of the received signal using a low-pass filter, a growing box filter, or a low-pass filter with self-correlation can be used to cancel a spur.
    Type: Grant
    Filed: April 6, 2011
    Date of Patent: May 22, 2012
    Assignee: Qualcomm Atheros, Inc.
    Inventors: Won-Joon Choi, Jeffrey M. Gilbert, Yi-Hsiu Wang, Xiaoru Zhang
  • Publication number: 20120121046
    Abstract: A system and method are disclosed for transmitting data over a wireless channel. In some embodiments, transmitting data includes receiving convolutionally encoded data and enhancing the transmission of the data by further repetition encoding the data.
    Type: Application
    Filed: January 23, 2012
    Publication date: May 17, 2012
    Applicant: Qualcomm Atheros, Inc.
    Inventors: Won-Joon Choi, Qinfang Sun, Jeffrey M. Gilbert
  • Patent number: 8134911
    Abstract: An OFDM-based device and method for performing synchronization utilizes a time-domain preamble of an incoming OFDM-based signal to compute an estimated fine frequency offset. The computation of the estimated fine frequency offset involves multiplying values of the time-domain preamble with conjugates of corresponding values of a selected base station time-domain preamble, averaging the resulting multiplied values in predefined segments and self-correlating the resulting averaged values to derive a self-correlation value, which is used to compute the estimated fine frequency offset.
    Type: Grant
    Filed: May 23, 2008
    Date of Patent: March 13, 2012
    Assignee: Amicus Wireless Technology Ltd.
    Inventors: Jingnong Yang, Won-Joon Choi
  • Patent number: 8135078
    Abstract: A device and method for performing a channel profile estimation for an OFDM-based wireless communication system uses an averaged frequency coherence metric to select a particular channel profile, which is a current channel profile estimate. The averaged frequency coherence metric is derived using correlations between pilot subcarriers of an OFDM-based signal at predefined subcarrier locations for multiple frames of the OFDM-based signal. The selected channel profile may be used for channel estimation, as well as for link adaptation, to improve the performance of these processes.
    Type: Grant
    Filed: May 1, 2008
    Date of Patent: March 13, 2012
    Assignee: Amicus Wireless Technology Ltd.
    Inventors: Kee-Bong Song, Won-Joon Choi
  • Patent number: 8130848
    Abstract: A device and method for performing a channel estimation for an OFDM-based wireless communication system using sparsely spaced pilot subcarriers estimates missing pilot subcarriers in an interpolation window using pilot subcarriers that are outside of the interpolation window to produce estimated pilot subcarriers for the interpolation window. The pilot subcarriers in the interpolation window and the estimated pilot subcarrier are used to compute pilot channel estimates for the interpolation window, which are then used to derive data channel estimates for the interpolation window.
    Type: Grant
    Filed: May 1, 2008
    Date of Patent: March 6, 2012
    Assignee: Amicus Wireless Technology Ltd.
    Inventors: Kee-Bong Song, Won-Joon Choi
  • Publication number: 20120039377
    Abstract: A multiple-input multiple-output (MIMO) system can transmit on multiple antennas simultaneously and receive on multiple antennas simultaneously. Unfortunately, because a legacy 802.11a/g device is not able to decode multiple data streams, such a legacy device may “stomp” on a MIMO packet by transmitting before the transmission of the MIMO packet is complete. Therefore, MIMO systems and methods are provided herein to allow legacy devices to decode the length of a MIMO packet and to restrain from transmitting during that period. These MIMO systems and methods are optimized for efficient transmission of MIMO packets.
    Type: Application
    Filed: October 28, 2011
    Publication date: February 16, 2012
    Applicant: Qualcomm Atheros, Inc.
    Inventors: Qinfang Sun, Won-Joon Choi, Jeffrey M. Gilbert, Ardavan Maleki Tehrani
  • Publication number: 20120028084
    Abstract: Disclosed herein is a spacer used in a battery pack having a plurality of battery cells mounted in a pack case, wherein the spacer is configured to have a top shape corresponding to the inner shape of the pack case in vertical section and a bottom shape corresponding to the outer circumferential shape of the battery cells in vertical section so that the spacer can be mounted in a space defined between the battery cells and the pack case, grooves, in which electrical connection members are mounted, are formed at the top of the spacer, and the spacer includes at least one temperature detection member mounting part including a horizontal opening open in one direction or in opposite directions and a vertical opening communicating with the horizontal opening so that a temperature detection member is inserted from one side of the spacer and mounted in a space defined between the battery cells.
    Type: Application
    Filed: January 6, 2010
    Publication date: February 2, 2012
    Applicant: LG CHEM, LTD
    Inventors: Youngsun Park, SooRyoung Kim, Seunghyun Bang, Won Joon Choi
  • Patent number: 8105909
    Abstract: A method of fabricating a non-volatile memory device includes: forming a tunnel insulation layer pattern and a floating gate electrode layer pattern over a semiconductor substrate; forming an isolation trench by etching an exposed portion of the semiconductor substrate so that the isolation trench is aligned with the tunnel insulation layer pattern and the floating gate electrode layer pattern; forming an isolation layer by filling the isolation trench with a filling insulation layer; forming a hafnium-rich hafnium silicon oxide layer over the isolation layer and the floating gate electrode layer pattern; forming a hafnium-rich hafnium silicon oxynitride layer by carrying out a first nitridation on the hafnium-rich hafnium silicon oxide layer; forming a silicon-rich hafnium silicon oxide layer over the hafnium-rich hafnium silicon oxynitride layer; forming a silicon-rich hafnium silicon oxynitride layer by carrying out a second nitridation on the silicon-rich hafnium silicon oxide layer; and forming a control
    Type: Grant
    Filed: September 29, 2010
    Date of Patent: January 31, 2012
    Assignee: Hynix Semiconductor Inc.
    Inventors: Moon Sig Joo, Heung Jae Cho, Yong Soo Kim, Won Joon Choi
  • Patent number: 8073072
    Abstract: A multiple-input multiple-output (MIMO) system can transmit on multiple antennas simultaneously and receive on multiple antennas simultaneously. Unfortunately, because a legacy 802.11a/g device is not able to decode multiple data streams, such a legacy device may “stomp” on a MIMO packet by transmitting before the transmission of the MIMO packet is complete. Therefore, MIMO systems and methods are provided herein to allow legacy devices to decode the length of a MIMO packet and to restrain from transmitting during that period. These MIMO systems and methods are optimized for efficient transmission of MIMO packets.
    Type: Grant
    Filed: September 29, 2009
    Date of Patent: December 6, 2011
    Assignee: Qualcomm Atheros, Inc.
    Inventors: Qinfang Sun, Won-Joon Choi, Jeffrey M. Gilbert, Ardavan Maleki Tehrani