Patents by Inventor Chae-Man Lim

Chae-Man Lim 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: 20090060094
    Abstract: Provided is a transmitting/receiving apparatus and method for an IDMA system. The receiving apparatus includes a channel estimator, an estimator, and a determiner. The channel estimator estimates a channel using a multi-user signal received through at least one RX antenna. The estimator estimates the noise power and the signal power for each transmission layer of each user by using the estimated channel value from the channel estimator. The determiner determines the number of transmission layers for each user and an MCS level for each transmission layer by using the signal power and the noise power estimated by the estimator.
    Type: Application
    Filed: August 20, 2008
    Publication date: March 5, 2009
    Inventors: Young-Seok Jung, Kwang-Man Ok, Chae-Man Lim
  • Patent number: 7450545
    Abstract: An apparatus and method determines soft handover in a Code Division Multiple Access (CDMA) mobile communication system supporting a Multimedia Broadcast Multicast Service (MBMS) service. In the CDMA mobile communication system supporting an MBMS service, when a User Equipment (UE) moves to a region where it can receive data from a plurality of Node Bs, the UE determines by itself whether to perform soft combining on MBMS data received from the Node Bs. Therefore, even though an MBMS user moves from an existing cell to a new cell, the MBMS service is stably provided, contributing to the convenience of the user.
    Type: Grant
    Filed: June 16, 2003
    Date of Patent: November 11, 2008
    Assignee: Samsung Electronics Co., Ltd
    Inventors: Young-Bum Kim, Sung-Ho Choi, Chae-Man Lim, Kook-Heui Lee, Soeng-Hun Kim, Ju-Ho Lee, Joon-Goo Park
  • Patent number: 7397784
    Abstract: An apparatus and method of receiving multi-path signals in a direct sequence Code Division Multiple Access (CDMA) mobile communication system is disclosed. Timing control signals from respective fingers are collected, and relations among positions of time delays where the respective fingers intend to perform a demodulation are analyzed. If it is determined that the time delay position for a specified finger approaches the time delay position of the finger allocated with an adjacent multi-path as close as a threshold value, the distance between the time delay positions is compulsorily kept as the threshold value. This can be effected by making the timing control signal of the finger allocated with the adjacent multi-path be equally used in the specified finger.
    Type: Grant
    Filed: October 9, 2003
    Date of Patent: July 8, 2008
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Dong-Ryeol Ryu, Seong-Kyu Hwang, Jae-Hawk Lee, Jeoung-Gil Lee, Chae-Man Lim
  • Publication number: 20080043702
    Abstract: A cell search using a Primary Synchronization Channel (P-SCH) and an Secondary Synchronization Channel (S-SCH) received from a Base Station (BS) are provided, in which a Mobile Station (MS) receives a P-SCH signal including at least two different P-SCH synchronization codes in different slots of a frame and detects slot timing and frame timing using the P-SCH signal.
    Type: Application
    Filed: August 17, 2007
    Publication date: February 21, 2008
    Applicant: SAMSUNG ELECTRONICS CO., LTD.
    Inventors: Hi-Chan MOON, Hoon Huh, Chae-Man Lim
  • Patent number: 7295539
    Abstract: An apparatus and method for generating reference timings. Each of at least two Node Bs transmits a first channel signal for providing a reference timing and a second channel signal different from the first channel signal and a UE has a plurality of fingers for demodulating the first channel signals. A first timing generator receives an SFN of a reference Node B having a communication link established with the UE, selects a first channel FB timing from a reference finger, and generates an SFN reference timing based on the SFN and the selected first channel FB timing. A second timing generator generates a second channel FB timing to demodulate the second channel signal of the reference Node B from the selected first channel FB timing through offset control. A third timing generator generates an uplink channel FB timing having a predetermined offset from the second channel FB timing.
    Type: Grant
    Filed: April 30, 2003
    Date of Patent: November 13, 2007
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Sung-Chul Han, Joo-Kwang Kim, Chae-Man Lim
  • Patent number: 7292548
    Abstract: An apparatus and method manages timings of Node Bs by performing a first-step cell search on primary synchronization channel signals transmitted from the Node Bs, and stores frame boundary indexes representing frame boundaries for the Node Bs by performing a second-step cell search on secondary synchronization channel signals received from the Node Bs. Upon receiving a third-step cell search start command, the apparatus and method compares frame boundary timing corresponding to each of the frame boundary indexes to a current timing from a reference timer, performs a third-step cell search on hypotheses corresponding to the frame boundary indexes at a next slot boundary following the current timing by using scrambling codes in a Node B code group obtained by the second-step cell search, and provides a third-step cell search complete information after completing the third-step cell search on hypotheses corresponding to the frame boundary indexes.
    Type: Grant
    Filed: April 23, 2003
    Date of Patent: November 6, 2007
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Chae-Man Lim, Yong-Serk Kim
  • Patent number: 7292551
    Abstract: A method of increasing the waiting time of a mobile terminal by reducing power consumption for a cell search in a discontinuous reception mode. In an embodiment of the invention, the strengths of signals from neighbor cells are measured and compared with a first threshold. Then a cell search is performed on only neighbor cells having signal strengths higher than the first threshold. In a second embodiment of the invention, a cell search is not performed if the signal strength of an active set is higher than a second threshold in a discontinuous reception mode. In a third embodiment of the invention, an offline cell search is performed in a discontinuous reception mode in the last step of three conventional cell search steps.
    Type: Grant
    Filed: October 10, 2002
    Date of Patent: November 6, 2007
    Inventors: Chae-Man Lim, Joo-Kwang Kim, Seong-Ho Hur, Dong-Ryeol Ryu, Kwang-Man Ok
  • Patent number: 7289483
    Abstract: There is provided a cell search apparatus and method in a mobile communication system. The cell search apparatus is slot time-synchronized by receiving a first synchronization code in each slot of a P-SCH frame and in addition receives over the slots of an S-SCH frame a base station group specific code representing one of base station groups and a base station specific code representing one of base stations in the base station group. In the cell search apparatus, a base station group specific code detecting unit detects the base station group specific code received on the S-SCH in the slot-synchronized state, and a base station specific code detecting unit detects a transmitting base station by detecting the base station specific code received following the base station group specific code.
    Type: Grant
    Filed: April 24, 2000
    Date of Patent: October 30, 2007
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Chae-Man Lim
  • Publication number: 20070200639
    Abstract: Provided is a device and a method for adjusting a loop filter gain in an automatic frequency controller, which can allow the automatic frequency controller to operate while maintaining an optimal performance. The device includes a velocity estimator for estimating a change in velocity in accordance with a movement of a terminal; a loop filter gain controller for controlling a loop filter gain in accordance with a change in velocity received from the velocity estimator; and a loop filter gain unit for multiplying a loop filter gain received from the loop filter gain controller and a frequency error for output. Further, there is provided a method for adjusting a loop filter gain in an automatic frequency controller, having the steps of: estimating a change in velocity in accordance with a movement of a terminal; adjusting a loop filter gain in accordance with the estimated change in velocity; and multiplying the adjusted loop filter value and a frequency error for output.
    Type: Application
    Filed: January 31, 2007
    Publication date: August 30, 2007
    Applicant: SAMSUNG ELECTRONICS CO., LTD.
    Inventors: Soo-Jin Park, Chae-Man Lim
  • Patent number: 7236468
    Abstract: A cell search apparatus and method in a W-CDMA mobile communication system. The cell search apparatus and method performs a first cell search step, a second cell search step, and a third cell search step using a slot count value and a lower count value, counted by an index counter after being initialized upon power up of a UE (User Equipment), thereby determining a scrambling code for a Node B. Further, the cell search apparatus and method manages neighboring Node Bs by performing a multipath search.
    Type: Grant
    Filed: October 8, 2002
    Date of Patent: June 26, 2007
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Dong-Ryeol Ryu, Joo-Kwang Kim, Kwang-Man Ok, Chae-Man Lim, Seong-Ho Hur
  • Publication number: 20050101271
    Abstract: A frequency error detector and combiner for use in a mobile communication system. The frequency error detector and combiner for use in a receiver of a mobile communication system which includes different frame formats according to slot formats, the receiver having at least two fingers including a frequency error detector for detecting a frequency error using a phase reference symbol of a predetermined channel received from a transmitter and a reference frequency error generator for generating a reference frequency error at predetermined reference time intervals using the detected frequency error; a level controller for controlling the gain of a frequency error generated from the reference frequency error generator; and a frequency error combiner for combining the gain controlled frequency error generated from each finger with a predetermined value.
    Type: Application
    Filed: October 15, 2004
    Publication date: May 12, 2005
    Applicant: SAMSUNG ELECTRONICS CO., LTD.
    Inventors: Won-Ick Ahn, Chae-Man Lim, Young-Seok Lim
  • Publication number: 20040253934
    Abstract: An apparatus and method of receiving multi-path signals in a direct sequence Code Division Multiple Access (CDMA) mobile communication system is disclosed. Timing control signals from respective fingers are collected, and relations among positions of time delays where the respective fingers intend to perform a demodulation are analyzed. If it is determined that the time delay position for a specified finger approaches the time delay position of the finger allocated with an adjacent multi-path as close as a threshold value, the distance between the time delay positions is compulsorily kept as the threshold value. This can be effected by making the timing control signal of the finger allocated with the adjacent multi-path be equally used in the specified finger.
    Type: Application
    Filed: October 9, 2003
    Publication date: December 16, 2004
    Inventors: Dong-Ryeol Ryu, Seong-Kyu Hwang, Jae-Hawk Lee, Jeoung-Gil Lee, Chae-Man Lim
  • Publication number: 20040227618
    Abstract: A method of paging UEs(User Equipments) on a multimedia broadcast/multicast service (MBMS) service basis in a mobile communication system supporting MBMS. To receive a PCH (Paging Channel) using a plurality of PICHs (Paging Indicator Channels) in a mobile communication system having a plurality of PCHs transmitted in every predetermined periods, for paging UEs requesting a broadcasting service, and the plurality of PICHs transmitted between first and second successive PCHs among the plurality of PCHs. A UE receives a PICH assigned to the UE if the PICH is among the plurality of PIs, determines whether the second PCH corresponding to the broadcasting service will be transmitted by a broadcasting service PI set in an unused part of the received PICH, and receives the second PCH destined commonly for all UEs that determine that the second PCH will be transmitted to the UEs among UEs that receive the PICH.
    Type: Application
    Filed: November 3, 2003
    Publication date: November 18, 2004
    Applicant: SAMSUNG ELECTRONICS CO., LTD.
    Inventors: Sung-Oh Hwang, Kook-Heui Lee, Sung-Ho Choi, Ki-Ho Cho, Chae-Man Lim
  • Patent number: 6741578
    Abstract: A synchronization (sync) code communication device for a CDMA communication system. A base station sync code transmission device comprises a primary sync code transmitter and a secondary sync code transmitter. The primary sync code transmitter is for generating and then transmitting a primary sync code at a first location in a transmission frame. The primary sync code is for acquiring synchronization at a starting point of a frame and the frame is equal to one period of a spreading code. The secondary sync code transmitter is for generating and then transmitting a secondary sync code at a second location in a frame. The secondary sync codes are assigned to base station groups, one to a group. A mobile station sync code receiving device comprises a primary sync code acquisition decider and a base station group decider. The primary sync code acquisition decider is for acquiring a primary sync code received at a first location in a frame, and then acquiring synchronization at a starting point of a frame.
    Type: Grant
    Filed: May 1, 2000
    Date of Patent: May 25, 2004
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Hi-Chan Moon, Chae-Man Lim, Seung-Joo Maeng, Soon-Young Yoon, Hyeon-Woo Lee, Hee-Won Kang, Jae-Min Ahn
  • Patent number: 6728229
    Abstract: A cell searching apparatus and method in a mobile communication system. In the cell searching method, a base station group specific code is determined from a synchronization channel signal in synchronization with slot time. Then, the predetermined base station group specific symbol cyclically reads a base station group specific code table. A code with a minimum distance estimation value with respect to a base station group specific code read from the base station group specific code table is chosen as a final base station group specific code.
    Type: Grant
    Filed: April 28, 2000
    Date of Patent: April 27, 2004
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Chae-Man Lim
  • Publication number: 20040047333
    Abstract: An apparatus and method for generating reference timings. Each of at least two Node Bs transmits a first channel signal for providing a reference timing and a second channel signal different from the first channel signal and a UE has a plurality of fingers for demodulating the first channel signals. A first timing generator receives an SFN of a reference Node B having a communication link established with the UE, selects a first channel FB timing from a reference finger, and generates an SFN reference timing based on the SFN and the selected first channel FB timing. A second timing generator generates a second channel FB timing to demodulate the second channel signal of the reference Node B from the selected first channel FB timing through offset control. A third timing generator generates an uplink channel FB timing having a predetermined offset from the second channel FB timing.
    Type: Application
    Filed: April 30, 2003
    Publication date: March 11, 2004
    Applicant: SAMSUNG ELECTRONICS CO.,LTD.
    Inventors: Sung-Chul Han, Joo-Kwang Kim, Chae-Man Lim
  • Publication number: 20030231612
    Abstract: An apparatus and method determines soft handover in a CDMA mobile communication system supporting an MBMS service. In the CDMA mobile communication system supporting an MBMS service, when a UE moves to a region where it can receive data from a plurality of Node Bs, the UE determines by itself whether to perform soft combining on MBMS data received from the Node Bs. Therefore, even though an MBMS user moves from an existing cell to a new cell, the MBMS service is stably provided, contributing to the convenience of the user.
    Type: Application
    Filed: June 16, 2003
    Publication date: December 18, 2003
    Applicant: SAMSUNG ELECTRONICS CO., LTD.
    Inventors: Young-Bum Kim, Sung-Ho Choi, Chae-Man Lim, Hook-Heui Lee, Soeng-Hun Kim, Ju-Ho Lee, Joon-Goo Park
  • Publication number: 20030202541
    Abstract: An apparatus and method manages timings of Node Bs by performing a first-step cell search on primary synchronization channel signals transmitted from the Node Bs, and stores frame boundary indexes representing frame boundaries for the Node Bs by performing a second-step cell search on secondary synchronization channel signals received from the Node Bs. Upon receiving a third-step cell search start command, the apparatus and method compares frame boundary timing corresponding to each of the frame boundary indexes to a current timing from a reference timer, performs a third-step cell search on hypotheses corresponding to the frame boundary indexes at a next slot boundary following the current timing by using scrambling codes in a Node B code group obtained by the second-step cell search, and provides a third-step cell search complete information after completing the third-step cell search on hypotheses corresponding to the frame boundary indexes.
    Type: Application
    Filed: April 23, 2003
    Publication date: October 30, 2003
    Inventors: Chae-Man Lim, Yong-Serk Kim
  • Publication number: 20030169702
    Abstract: A cell search apparatus and method in a W-CDMA mobile communication system. The cell search apparatus and method performs a first cell search step, a second cell search step, and a third cell search step using a slot count value and a lower count value, counted by an index counter after being initialized upon power up of a UE (User Equipment), thereby determining a scrambling code for a Node B. Further, the cell search apparatus and method manages neighboring Node Bs by performing a multipath search.
    Type: Application
    Filed: October 8, 2002
    Publication date: September 11, 2003
    Applicant: SAMSUNG ELECTRONICS CO., LTD.
    Inventors: Dong-Ryeol Ryu, Joo-Kwang Kim, Kwang-Man Ok, Chae-Man Lim, Seong-Ho Hur
  • Publication number: 20030117996
    Abstract: A method of increasing the waiting time of a mobile terminal by reducing power consumption for a cell search in a discontinuous reception mode. In an embodiment of the invention, the strengths of signals from neighbor cells are measured and compared with a first threshold. Then a cell search is performed on only neighbor cells having signal strengths higher than the first threshold. In a second embodiment of the invention, a cell search is not performed if the signal strength of an active set is higher than a second threshold in a discontinuous reception mode. In a third embodiment of the invention, an offline cell search is performed in a discontinuous reception mode in the last step of three conventional cell search steps.
    Type: Application
    Filed: October 10, 2002
    Publication date: June 26, 2003
    Applicant: SAMSUNG ELECTRONICS CO., LTD.
    Inventors: Chae-Man Lim, Joo-Kwang Kim, Seong-Ho Hur, Dong-Ryeol Ryu, Kwang-Man Ok