Patents by Inventor Eoi-Young Choi
Eoi-Young 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).
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Patent number: 8184725Abstract: A receiver and method of performing timing synchronization in an orthogonal frequency division multiplexing (OFDM) scheme. A receiver to perform timing synchronization in an OFDM scheme, the receiver including: an autocorrelation processor to calculate and accumulate an autocorrelation value with regard to samples of an OFDM symbol before an initialized starting point; and a reference value calculator to calculate the reference value of each sample index in at least one predetermined sample section, based on the accumulated autocorrelation values, wherein the reference value corresponds to a value dividing an imaginary number unit of the accumulated autocorrelation values into a real number unit, and is used to repeatedly reestablish the initialized starting point and to determine the final starting point.Type: GrantFiled: February 13, 2007Date of Patent: May 22, 2012Assignee: Samsung Electronics Co., Ltd.Inventors: Eoi Young Choi, Joon Hyun Sung, Kwang Chul Kim, Jeong Taek Lee
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Patent number: 8077783Abstract: Provided are a method and apparatus for detecting a transmission symbol using a lattice-reduction matrix in a Multiple Input Multiple Output (MIMO) system. The transmission symbol detection method includes: restoring an original transmission symbol from a reception signal received through the plurality of antennas; and obtaining at least one noise component included in the reception signal from a constellation changed due to applying the lattice-reduction matrix, exchanging a position of the at least one noise component under a predetermined condition which depends on a state of the restored transmission symbol, and processing the at least one noise component whose position is changed, together with the restored transmission symbol, thereby providing a soft output. Therefore, it is possible to obtain a performance gain in channel decoding.Type: GrantFiled: April 4, 2008Date of Patent: December 13, 2011Assignee: Samsung Electronics Co., Ltd.Inventors: Eoi-Young Choi, Jeong-Taek Lee, Joon-Hyun Sung
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Patent number: 8006162Abstract: Disclosed is a method for puncturing a Low Density Parity Check (LDPC) code that is expressed by a factor graph having a check node and a variable node, connected to each other by an edge, and is decoded by a parity check matrix including a parity part having a single weight-3 column and a dual-diagonal matrix. The method includes selecting 1-step recoverable (1-SR) variable nodes with the highest quality including a variable node mapped to a weight-3 column, and setting a first puncturing priority group using the selected 1-SR variable nodes, selecting k-step recoverable (k-SR) variable nodes with the highest quality in the next step k taking into account the variable nodes selected in the current step, and setting a priority group for each individual step, puncturing an LDPC code mapped to a variable node belonging to a corresponding group according to priority of each group obtained in the preceding steps.Type: GrantFiled: May 16, 2006Date of Patent: August 23, 2011Assignee: Samsung Electronics Co., Ltd.Inventors: Eoi-Young Choi, Seung-Bum Suh
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Patent number: 7933370Abstract: A Multiple Input Multiple Output (MIMO) receiver and a signal detection method thereof are provided. Since no square root calculation needs to be performed when a calculation for detecting a transmission signal is performed using a Zero Forcing-Sorted QR Decomposition (ZF-SQRD) algorithm and a Minimum Mean Square Error-Sorted QR Decomposition (MMSE-SQRD) algorithm, the complexity of a calculation for detecting a transmission signal under a MIMO channel environment can be reduced.Type: GrantFiled: March 18, 2008Date of Patent: April 26, 2011Assignee: Samsung Electronics Co., Ltd.Inventors: Jeong-Taek Lee, Eoi-Young Choi
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Patent number: 7930620Abstract: A method is provided for updating a check node in a low density parity check (LDPC) decoder, including: transmitting log-likelihood ratio (LLR) messages from variable nodes to a plurality of check nodes; decomposing the LLR messages in a plurality of node messages for each check node; and updating each check node using a modified function g(x), which is a function g?(x) comprising a sum operation of exponential functions based on the node messages.Type: GrantFiled: October 4, 2006Date of Patent: April 19, 2011Assignee: Samsung Electronics Co., Ltd.Inventors: Eoi-young Choi, Jae-ho Roh, Young-chai Ko, Ki-hong Park
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Patent number: 7801230Abstract: A method and apparatus for estimating a channel in an Orthogonal Frequency Division Multiplexing (OFDM) wireless communication system. A Least-Square (LS) channel estimator receives a training sequence, and performs LS channel estimation on each of a predetermined number of subcarriers independently. A Split Minimum-Mean-Square-Error (S-MMSE) channel estimator separates the predetermined number of subcarriers into a predetermined number of groups, calculates an S-MMSE filter for a subcarrier in each group, and estimates an S-MMSE channel by applying the S-MMSE filter to each of the groups.Type: GrantFiled: June 11, 2007Date of Patent: September 21, 2010Assignee: Samsung Electronics Co., Ltd.Inventors: Joon-Hyun Sung, Jeong-Taek Lee, Eoi-Young Choi
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Patent number: 7743312Abstract: A method is provided for puncturing a low density parity check (LDPC) code decoded by a parity check matrix that is expressed by a factor graph including a check node and a bit node, being connected to each other at an edge, and includes a parity part having a dual diagonal matrix with a single 3-weight column and the remaining columns being 2-weight columns. The method includes generating a puncturing pattern such that bits of the LDPC code are punctured in an order of a bit mapped to a column with a higher weight from among the columns constituting the parity part; and puncturing the LDPC code according to the generated puncturing pattern.Type: GrantFiled: March 3, 2006Date of Patent: June 22, 2010Assignee: Samsung Electronics Co., Ltd.Inventors: Eoi-Young Choi, Seung-Bum Suh
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Patent number: 7653859Abstract: A system, an apparatus and a method for transmitting/receiving data coded by a low density parity check matrix code are provided. The apparatus for transmitting data coded by a low density parity check code includes: a low density parity check encoder for encoding input data based on the low density parity check code; and a bit puncturer for puncturing columns in an order of columns which least degrade a performance caused by puncturing in the low density check code according to a code rate of an output data. Accordingly, the low density parity check code having superior performance can be implemented to the next generation mobile communication system supporting various code rates.Type: GrantFiled: April 22, 2005Date of Patent: January 26, 2010Assignee: Samsung Electronics Co., Ltd.Inventors: Eoi-Young Choi, Jaehong Kim, Jae-hyun Koo, Seung-bum Suh
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Publication number: 20090185631Abstract: Provided are a method and apparatus for detecting a transmission symbol using a lattice-reduction matrix in a Multiple Input Multiple Output (MIMO) system. The transmission symbol detection method includes: restoring an original transmission symbol from a reception signal received through the plurality of antennas; and obtaining at least one noise component included in the reception signal from a constellation changed due to applying the lattice-reduction matrix, exchanging a position of the at least one noise component under a predetermined condition which depends on a state of the restored transmission symbol, and processing the at least one noise component whose position is changed, together with the restored transmission symbol, thereby providing a soft output. Therefore, it is possible to obtain a performance gain in channel decoding.Type: ApplicationFiled: April 4, 2008Publication date: July 23, 2009Inventors: Eoi-Young Choi, Jeong-Taek Lee, Joon-Hyun Sung
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Publication number: 20090097598Abstract: A Multiple Input Multiple Output (MIMO) receiver and a signal detection method thereof are provided. Since no square root calculation needs to be performed when a calculation for detecting a transmission signal is performed using a Zero Forcing-Sorted QR Decomposition (ZF-SQRD) algorithm and a Minimum Mean Square Error-Sorted QR Decomposition (MMSE-SQRD) algorithm, the complexity of a calculation for detecting a transmission signal under a MIMO channel environment can be reduced.Type: ApplicationFiled: March 18, 2008Publication date: April 16, 2009Applicant: SAMSUNG ELECTRONICS CO., LTD.Inventors: Jeong-taek LEE, Eoi-young Choi
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Patent number: 7451374Abstract: Disclosed are an apparatus and a method for reducing the coding complexity in an LDPC code used in a digital communication system. In the method, parameters required for coding are determined according to a coding rate and a code length, a seed matrix is generated according to values of the parameters, a plurality of cell matrices are generated according to the values of the parameters, a parity check matrix is generated using the seed matrix and the cell matrix, and information bits are coded from the parity check matrix. The method can be realized by a small memory and a simple shift register and can perform coding even without obtaining a generation matrix, thereby remarkably reducing the complexity of a system.Type: GrantFiled: July 27, 2005Date of Patent: November 11, 2008Assignee: Samsung Electronics Co., LtdInventors: Nam-Shik Kim, Hyun-Cheol Park, Seung-Bum Suh, Eoi-Young Choi
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Patent number: 7409000Abstract: Disclosed is a space-time trellis code (STTC) encoding method for performing space-time coding of a serially-concatenated space-time code (SC-STC) in an encoder having an outer encoder for performing channel coding and an inner encoder for performing the space-time coding, in a mobile communication system including one or more transmission antennas, by transmitting via a first transmission antenna a symbol generated by encoding a first input signal output from the outer encoder by a first recursive convolutional encoder and a symbol generated by encoding a second input signal output from the outer encoder by a second recursive convolutional encoder; and transmitting via a second transmission antenna the first and second input signals.Type: GrantFiled: December 2, 2004Date of Patent: August 5, 2008Assignee: Samsung Electronics Co., Ltd.Inventors: Eoi-Young Choi, Seung-Bum Suh, Jun-Hong Hui, Ying Li
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Publication number: 20080101486Abstract: A receiver and method of performing timing synchronization in an orthogonal frequency division multiplexing (OFDM) scheme. A receiver to perform timing synchronization in an OFDM scheme, the receiver including: an autocorrelation processor to calculate and accumulate an autocorrelation value with regard to samples of an OFDM symbol before an initialized starting point; and a reference value calculator to calculate the reference value of each sample index in at least one predetermined sample section, based on the accumulated autocorrelation values, wherein the reference value corresponds to a value dividing an imaginary number unit of the accumulated autocorrelation values into a real number unit, and is used to repeatedly reestablish the initialized starting point and to determine the final starting point.Type: ApplicationFiled: February 13, 2007Publication date: May 1, 2008Applicant: Samsung Electronics Co., Ltd.Inventors: Eoi Young CHOI, Joon Hyun Sung, Kwang Chul Kim, Jeong Taek Lee
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Publication number: 20080080636Abstract: A method and apparatus for estimating a channel in an Orthogonal Frequency Division Multiplexing (OFDM) wireless communication system. A Least-Square (LS) channel estimator receives a training sequence, and performs LS channel estimation on each of a predetermined number of subcarriers independently. A Split Minimum-Mean-Square-Error (S-MMSE) channel estimator separates the predetermined number of subcarriers into a predetermined number of groups, calculates an S-MMSE filter for a subcarrier in each group, and estimates an S-MMSE channel by applying the S-MMSE filter to each of the groups.Type: ApplicationFiled: June 11, 2007Publication date: April 3, 2008Applicant: SAMSUNG ELECTRONICS CO., LTD.Inventors: Joon-Hyun SUNG, Jeong-Taek LEE, Eoi-Young CHOI
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Publication number: 20070094568Abstract: A method is provided for updating a check node in a low density parity check (LDPC) decoder, including: transmitting log-likelihood ratio (LLR) messages from variable nodes to a plurality of check nodes; decomposing the LLR messages in a plurality of node messages for each check node; and updating each check node using a modified function g(x), which is a function g?(x) comprising a sum operation of exponential functions based on the node messages.Type: ApplicationFiled: October 4, 2006Publication date: April 26, 2007Inventors: Eoi-young Choi, Jae-ho Roh, Young-chai Ko, Ki-hong Park
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Publication number: 20070011567Abstract: Disclosed is a method for puncturing a Low Density Parity Check (LDPC) code that is expressed by a factor graph having a check node and a variable node, connected to each other by an edge, and is decoded by a parity check matrix including a parity part having a single weight-3 column and a dual-diagonal matrix. The method includes selecting 1-step recoverable (1-SR) variable nodes with the highest quality including a variable node mapped to a weight-3 column, and setting a first puncturing priority group using the selected 1-SR variable nodes, selecting k-step recoverable (k-SR) variable nodes with the highest quality in the next step k taking into account the variable nodes selected in the current step, and setting a priority group for each individual step, puncturing an LDPC code mapped to a variable node belonging to a corresponding group according to priority of each group obtained in the preceding steps.Type: ApplicationFiled: May 16, 2006Publication date: January 11, 2007Applicant: SAMSUNG ELECTRONICS CO., LTD.Inventors: Eoi-Young Choi, Seung-Bum Suh
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Publication number: 20060206781Abstract: A method is provided for puncturing a low density parity check (LDPC) code decoded by a parity check matrix that is expressed by a factor graph including a check node and a bit node, being connected to each other at an edge, and includes a parity part having a dual diagonal matrix with a single 3-weight column and the remaining columns being 2-weight columns. The method includes generating a puncturing pattern such that bits of the LDPC code are punctured in an order of a bit mapped to a column with a higher weight from among the columns constituting the parity part; and puncturing the LDPC code according to the generated puncturing pattern.Type: ApplicationFiled: March 3, 2006Publication date: September 14, 2006Applicant: Samsung Electronics Co., Ltd.Inventors: Eoi-Young Choi, Seung-Bum Suh
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Publication number: 20060140304Abstract: Provided is a generalized Recursive STTC (Space-Time Trellis Code) encoder which can improve diversity gain and coding gain in terms of transmission without increasing circuit complexity in a transmission system by forming an internal encoder of a multi-antenna mobile telecommunication system using a Recursive Systematic Convolutional code (RSC) block having two output ends to form a systematic ineral encoder. In addition, the generalized RSTTC encoder has a ratio of input data to output data (n?1):n by using a plurality of parallel RSC blocks each having two output ends. Thus, flexibility can be given to the size of data input to each RSC block and a transmission data rate can be improved in the internal encoder of a transmission system.Type: ApplicationFiled: December 7, 2005Publication date: June 29, 2006Applicant: Samsung Electronics Co., Ltd.Inventors: Ying Li, Junhong Hui, Eoi-Young Choi, Xinmei Wang
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Publication number: 20060029149Abstract: An improved receiver for a multicarrier-based MIMO (Multiple-Input Multiple-Output) system is provided. A MIMO receiving apparatus includes a detection priority decision unit, which receives via N receiving antennas signals transmitted from M transmitting antennas and determines the detection priorities of the signals, and a signal detector, which successively detects the signals in a decreasing order from a signal having a higher priority according to the detection priorities determined by the detection priority decision unit. System complexity can be reduced by minimizing the number of the inverse matrix calculations required for an SIC mechanism using one MIMO DFE and MISO DFEs corresponding to the number of transmitting antennas.Type: ApplicationFiled: August 4, 2005Publication date: February 9, 2006Applicant: SAMSUNG ELECTRONICS CO., LTD.Inventors: Hyoun-Kuk Kim, Hyun-Cheol Park, Seung-Bum Suh, Eoi-Young Choi
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Publication number: 20060026488Abstract: Disclosed are an apparatus and a method for reducing the coding complexity in an LDPC code used in a digital communication system. In the method, parameters required for coding are determined according to a coding rate and a code length, a seed matrix is generated according to values of the parameters, a plurality of cell matrices are generated according to the values of the parameters, a parity check matrix is generated using the seed matrix and the cell matrix, and information bits are coded from the parity check matrix. The method can be realized by a small memory and a simple shift register and can perform coding even without obtaining a generation matrix, thereby remarkably reducing the complexity of a system.Type: ApplicationFiled: July 27, 2005Publication date: February 2, 2006Applicant: SAMSUNG ELECTRONICS CO., LTD.Inventors: Nam-Shik Kim, Hyun-Cheol Park, Seung-Bum Suh, Eoi-Young Choi