Patents by Inventor Choong-Il Yeh
Choong-Il Yeh 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: 8718167Abstract: Disclosed is a method for channel estimation and feedback in a wireless communication system that estimates a channel for each transmission antenna using an orthogonal frequency division multiplexing (OFDM) impulse signal.Type: GrantFiled: September 10, 2008Date of Patent: May 6, 2014Assignees: Samsung Electronics Co., Ltd., Electronics and Telecommunications Research InstituteInventors: Choong il Yeh, Dong Seung Kwon, Jee Hwan Ahn
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Patent number: 8619714Abstract: An access point allocates a resource for ranging to an access terminal included therein, and receives a ranging channel that includes an identifier of the access terminal and a plurality of pilots. The AP checks the access terminal by using the received identifier, and measures a round trip delay of the access terminal based on the received pilots.Type: GrantFiled: May 6, 2009Date of Patent: December 31, 2013Assignee: Electronics and Telecommunications Research InstituteInventors: Choong Il Yeh, Byung-Jae Kwak, Dong Seung Kwon, Jee Hwan Ahn
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Patent number: 8611314Abstract: A method of transmitting a synchronization channel is provided. A plurality of block sequences for determining at least one block identifier is generated. A plurality of subcarriers of a synchronization channel are divided into a polarity of blocks, and the plurality of block sequences are allocated to the blocks to generate a synchronization signal.Type: GrantFiled: March 20, 2009Date of Patent: December 17, 2013Assignee: Electronics and Telecommunications Research InstituteInventors: Seung Joon Lee, Choong Il Yeh, Dong Seung Kwon
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Patent number: 8611441Abstract: The present invention relates to a transmission interference cancellation method for a multiuser MIMO system. The method includes decomposing a channel matrix to represent formulae of permutation matrixes including a first matrix and a second matrix; determining an optimal permutation matrix among a plurality of available permutation matrixes using a norm of multiplication of the second matrix and a transmitting data vector; and determining the second matrix using the determined optimal permutation matrix and calculating a transmitting precoding vector using the determined second matrix and the transmitting data vector.Type: GrantFiled: August 22, 2008Date of Patent: December 17, 2013Assignees: Samsung Electronics Co., Ltd., Electronics and Telecommunications Research InstituteInventors: Choong Il Yeh, Seung Joon Lee, Dong Seung Kwon
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Patent number: 8537917Abstract: In a symbol mapping method, transmission data is encoded to generate information bits and redundancy bits. An average LLR value of bits on which the information bits are mapped is different from an average LLR value of bits on which the redundancy bits are mapped.Type: GrantFiled: March 10, 2009Date of Patent: September 17, 2013Assignee: Electronics and Telecommunications Research InstituteInventors: Dong Seung Kwon, Byung-Jae Kwak, Bum-Soo Park, Choong Il Yeh, Young Seog Song, Seung Joon Lee, Ji Hyung Kim
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Patent number: 8526531Abstract: The present invention relates to an apparatus and a method for selection of a precoding matrix. In the present invention, a precoding matrix to enable an effective signal-to-noise ratio (ESNR) to have a maximum value with respect to a signal vector that requires retransmission is selected in a codebook and fed back to a transmitter. Accordingly, since the effective signal-to-noise ratio has the maximum value after the signal vector is retransmitted, it is possible to minimize a reception error probability of retransmission.Type: GrantFiled: April 22, 2009Date of Patent: September 3, 2013Assignees: Samsung Electronics Co., Ltd., Electronics and Telecommunications Research InstituteInventors: Dong Seung Kwon, Byung-Jae Kwak, Young Seog Song, Seung Joon Lee, Ji Hyung Kim, Choong Il Yeh, Wooram Shin, Chung Gu Kang, Jin-Woo Kim
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Patent number: 8509336Abstract: Disclosed is a transmitting/receiving method in a multi-user multiple-input multiple-output (MU-MIMO) channel. The transmitting method includes: performing QR decomposition on a Hermitian transpose matrix of a channel matrix to obtain a first matrix and a second matrix as a triangular matrix; obtaining a preprocessing matrix by using the first matrix; and forming an effective channel based on the preprocessing matrix by a block triangulation technique.Type: GrantFiled: June 24, 2008Date of Patent: August 13, 2013Assignees: Samsung Electronics Co., Ltd., Electronics & Telecommunications Research InstituteInventors: Choong il Yeh, In-Kyeong Choi, Young Seog Song, Seung Joon Lee, Byung-Jae Kwak, Ji Hyung Kim, Dong Seung Kwon, Joon Doo Kim, Ji Won Kang, Chung Yong Lee
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Patent number: 8331298Abstract: The present invention relates to an uplink control channel configuration in a mobile wideband wireless access system, and an allocation method thereof. An uplink control channel includes a long cyclic prefix used to improve interference and distortion caused by multipath transmission characteristics of an initial ranging or handover ranging signal and a periodic ranging or band request ranging signal. In addition, a short orthogonal frequency division multiple (OFDM) symbol is used to transmit uplink control information when one terminal exists or the number of terminals is small.Type: GrantFiled: December 7, 2007Date of Patent: December 11, 2012Assignees: Samsung Electronics Co., Ltd., Electronics and Telecommunications Research InstituteInventors: Choong-Il Yeh, Dong-Seung Kwon, Jee-Hwan Ahn
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Patent number: 8243707Abstract: The present invention relates to a method of forming a random beam, and a beam forming apparatus. A quantization preprocessor and a random unitary matrix having a predetermined pattern are used to form a beam on a mobile terminal. A base station forms a beam using a codeword index of a quantization codebook received from a mobile terminal and channel quality information corresponding to the codeword index, and the mobile terminal generates the codeword index and the channel quality information using pilot signals generated by the base station. The number of pilot signals is equal to the number of transmitting antennas. Therefore, a codebook that has been known to both the mobile terminal and the base station is used, and the mobile terminal can select the codeword index for quantization, which makes it possible to selectively give diversity and thus improve the system efficiency.Type: GrantFiled: October 10, 2007Date of Patent: August 14, 2012Assignees: Samsung Electronics Co., Ltd., Electronics and Telecommunications Research InstituteInventors: In-Kyeong Choi, Dong-Seung Kwon, Choong-Il Yeh, Ji-Won Kang, Chung-Yong Lee
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Patent number: 8121208Abstract: The present invention relates to a multi-input multi-output (MIMO) system for enhancing transmission performance. The MIMO system uses space-time encoding and transmit antenna selection methods, and includes a transmitter (100) and a receiver (200). The transmitter (100) includes N transmit antennas (130-1, 130-4) that are more than M transmit antennas (130-1, 130-3) used for transmitting a signal to space channel, selects the M transmit antennas (130-1, 130-3) among the N transmit antennas (130-3 130-4), and transmits symbol by space-time encoding the symbol. The receiver (200) includes M receive antenna (120-1, 210-2) for receiving a signal from the space channel, detects an information symbol by using the signal received through the receive antenna (210-1, 210-2), generates transmit antenna selection information for selecting M transmit antennas (130-1, 130-3) among transmit antennas (i30-1, . . . 7130-4) with reference to a channel estimate, and returns the information to the transmitter.Type: GrantFiled: August 10, 2005Date of Patent: February 21, 2012Assignees: Electronics and Telecommunications Research Institute, Industry-Academic Cooperation Foundation, Yonsei UniversityInventors: Young-Seog Song, Seong-Rag Kim, In-Kyeong Choi, Choong-Il Yeh, Seung-Joon Lee, Hyoung-Soo Lim, Kwang-Jae Lim, Yu-Ro Lee, Jong-Ee Oh, Dong-Seung Kwon, Seung-Ku Hwang, Chung-Yong Lee, Myeong-Cheol Shin
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Patent number: 7925234Abstract: The present invention relates to a maximum ratio combining method of spatial-filtered received signals and an apparatus using the same. For this purpose the present invention provides a method for receiving signals by using a plurality of antennas that form a linear array antenna, multiplying a plurality of weight vectors by the received signals, summing the multiplication results for each weight vector, and combining the summing results by using maximum ratio combining. According to the present invention, signals are dividedly received by applying spatial filtering for a receiving direction of each signal and performance can be improved by combining the received signals by using maximum ratio combining. In addition, performance of an MRC-rake and a beam forming gain can be simultaneously acquired according to the present invention.Type: GrantFiled: September 28, 2006Date of Patent: April 12, 2011Assignees: Samsung Electronics Co., Ltd., Electronics and Telecommunications Research Institute, KT Corporation, SK Telecom Co., Ltd., Hanaro Telecom, Inc.Inventors: Choong-Il Yeh, Jae-Joon Park, Chul-Sik Yoon
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Patent number: 7920646Abstract: The present invention relates to a system for selecting a switched beam for supplying a maximum received power to a subscriber station, and a method thereof. The number of switched beams used by a base station is limited, and a weight value vector for forming the switched beam is predefined. The subscriber station uses a pilot signal for discerning transmitting antennas to estimate channel values for the respective transmitting antennas, and uses the channel values and the predefined weight value vectors to determine a switched beam for supplying a maximum signal-to-noise ratio (SNR). The subscriber station notifies the base station of an identifier of a selected beam by using a feedback channel, and the base station uses the switched beam to transmit traffic data.Type: GrantFiled: December 21, 2005Date of Patent: April 5, 2011Assignee: Samsung Electronics Co., LtdInventors: Choong-Il Yeh, Young-Seog Song, In-Kyeong Choi, Dong-Seung Kwon
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Publication number: 20110058533Abstract: An access point allocates a resource for ranging to an access terminal included therein, and receives a ranging channel that includes an identifier of the access terminal and a plurality of pilots. The AP checks the access terminal by using the received identifier, and measures a round trip delay of the access terminal based on the received pilots.Type: ApplicationFiled: May 6, 2009Publication date: March 10, 2011Inventors: Choong Il Yeh, Byung-Jae Kwak, Dong Seung Kwon, Jee Hwan Ahn
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Patent number: 7903753Abstract: A space-time code used for a transmitter to transmit a plurality of data symbols to a receiver in a MIMO system, the space-time code including a code word matrix for transmitting an amount of data symbols corresponding to a product of the number of transmit antennas and a spatial multiplexing rate during one block period, wherein a row index indicates combined signals transmitted through different transmit antennas and a column index indicates time slots that correspond to the number of transmit antennas, and wherein the number of data symbols allocated to each transmit antenna in a code block corresponds to the spatial multiplexing rate, and the data symbols are combined by different combining coefficients for each transmit antenna at every time slot, and simultaneously transmitted through different transmit antennas, and each transmit antenna transmits a different set of data symbols at every time slot.Type: GrantFiled: February 28, 2005Date of Patent: March 8, 2011Assignee: Electronics and Telecommunications Research InstituteInventors: Seung-Joon Lee, Choong-Il Yeh, Dong-Seung Kwon, Seung-Ku Hwang, Hyoung-Soo Lim, In-Kyeong Choi, Jong-Ee Oh, Kwang-Jae Lim, Seong-Rag Kim, Young-Seog Song, Yu-Ro Lee, Seong-Keun Oh, Moon-Il Lee
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Publication number: 20110044301Abstract: A method of transmitting a synchronization channel is provided. A plurality of block sequences for determining at least one block identifier is generated. A plurality of subcarriers of a synchronization channel are divided into a polarity of blocks, and the plurality of block sequences are allocated to the blocks to generate a synchronization signal.Type: ApplicationFiled: March 20, 2009Publication date: February 24, 2011Inventors: Seung Joon Lee, Choong Il Yeh, Dong Seung Kwon
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Publication number: 20110033010Abstract: The present invention relates to an apparatus and a method for selection of a precoding matrix. In the present invention, a precoding matrix to enable an effective signal-to-noise ratio (ESNR) to have a maximum value with respect to a signal vector that requires retransmission is selected in a codebook and fed back to a transmitter. Accordingly, since the effective signal-to-noise ratio has the maximum value after the signal vector is retransmitted, it is possible to minimize a reception error probability of retransmission.Type: ApplicationFiled: April 22, 2009Publication date: February 10, 2011Inventors: Dong Seung Kwon, Byung-Jae Kwak, Young Seog Song, Seung Joon Lee, Ji Hyung Kim, Choong Il Yeh, Wooram Shin, Chung Gu Kang, Jin-Woo Kim
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Publication number: 20110026628Abstract: In a symbol mapping method, transmission data is encoded to generate information bits and redundancy bits. An average LLR value of bits on which the information bits are mapped is different from an average LLR value of bits on which the redundancy bits are mapped.Type: ApplicationFiled: March 10, 2009Publication date: February 3, 2011Inventors: Dong Seung Kwon, Byung-Jae Kwak, Bum-Soo Park, Choong Il Yeh, Seung Joon Lee, Ji Hyung Kim
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Publication number: 20100322223Abstract: The present invention relates to a method of forming a random beam, and a beam forming apparatus. A quantization preprocessor and a random unitary matrix having a predetermined pattern are used to form a beam on a mobile terminal. A base station forms a beam using a codeword index of a quantization codebook received from a mobile terminal and channel quality information corresponding to the codeword index, and the mobile terminal generates the codeword index and the channel quality information using pilot signals generated by the base station. The number of pilot signals is equal to the number of transmitting antennas. Therefore, a codebook that has been known to both the mobile terminal and the base station is used, and the mobile terminal can select the codeword index for quantization, which makes it possible to selectively give diversity and thus improve the system efficiency.Type: ApplicationFiled: October 10, 2007Publication date: December 23, 2010Inventors: In-Kyeong Choi, Dong-Seung Kwon, Choong-Il Yeh, Ji-Won Kang, Chung-Yong Lee
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Publication number: 20100322160Abstract: The present invention relates to an uplink control channel configuration in a mobile wideband wireless access system, and an allocation method thereof. An uplink control channel includes a long cyclic prefix used to improve interference and distortion caused by multipath transmission characteristics of an initial ranging or handover ranging signal and a periodic ranging or band request ranging signal. In addition, a short orthogonal frequency division multiple (OFDM) symbol is used to transmit uplink control information when one terminal exists or the number of terminals is small.Type: ApplicationFiled: December 7, 2007Publication date: December 23, 2010Applicant: SAMSUNG ELECTRONICS CO., LTD.Inventors: Choong-Il Yeh, Dong-Seung Kwon, Jee-Hwan Ahn
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Publication number: 20100316145Abstract: Disclosed is a method for channel estimation and feedback in a wireless communication system that estimates a channel for each transmission antenna using an orthogonal frequency division multiplexing (OFDM) impulse signal.Type: ApplicationFiled: September 10, 2008Publication date: December 16, 2010Applicant: SAMSUNG ELECTRONICS CO., LTD.Inventors: Choong il Yeh, Dong Seung Kwon, Jee Hwan Ahn