Electronics and Telecommunications Research Institute

Samsung Electronics Co., Ltd.

Kt Corporation

Sk Telecom Company, Ltd.

Hanaro Telecom., Inc.

Utstarcom, Incorporated

Hyundai Electronics Industries Co. Ltd.

Ktfreetel Co., Ltd

Yonsei University

Utstarcom Korea Limited (c/o of Utstarcom, Inc.)

Yu-Ro Lee

Sok-Kyu Lee

Jong-Ee Oh

Dong-Seung Kwon

Minho Cheong

Jae-Hong Park

Chong-Won Lee

In-Kyeong Choi

Jung-Bo Son

Ho-Geun Lee

Hyoung-Soo Lim

Jeong-Hwa Ye

Il-Gu Lee

Hee-Jung Yu

Kwang-Jae Lim

Seung-Joon Lee

Seung-Chan Bang

Eun-Young Choi

Yun-Joo Kim

Chanho Yoon

Seung-Ku Hwang

Min-Ho Cheong

Seong-Rag Kim

Chan-Ho Yoon

Choong-Il Yeh

Young-Seog Song

Hyun-Kyu Chung

Jeeyon Choi

Chung-Yong Lee

Seong-Keun Oh

Woon-Hee Hwang

Dong-Cheol Kim

Yoo-Seung Song

Myeong-Cheol Shin

Hyun-Joon Shin

Een-Kee Hong

Je-Hun Lee

Kwhang-Hyun Ryu

Byung-Chan Kim

Hyung-Soo Lim

Young-Gyun Kim

Moon-Il Lee

Cheol-Jung Kim

Tae-Hyun Jeon

Choong-II Yeh

Choomg-Il Yeh

Jong-Eo Oh

Jeevon Choi

The present invention relates to a method and an apparatus for transmitting control and training symbols to improve transmission efficiency in a multi-user wireless communication system. The method for transmitting the control and training symbols in the multi-user wireless communication system according to one embodiment of the present invention comprises the steps of: determining whether a required transmission rate of each data can be satisfied through channel estimation in each of terminals when different data are simultaneously transmitted to each of the terminals; and transmitting a data frame to each of the terminals, the data frame being composed to discriminate the control and training symbols in each of the terminals using a combination of time, frequency, and code area when the required transmission rate of each data is not satisfied according to the determined result.

Method for transmitting control and training symbols in multi-user wireless communication system

The present invention particularly relates to a method and an apparatus for improving the efficiency of data transmission in a multi-user wireless transmission system. According to one embodiment of the present invention, the method, which is a transmission method of data in a multi-user wireless communication system, comprises the steps of: estimating channel states of each terminal through sounding or feedback information received from the terminals, and selecting terminals to which individual data are to be transmitted at the same time; determining a signal to noise ratio of the selected terminals, and calculating a precoding matrix; calculating a modulation and coding scheme (MCS) of each terminal and the number of symbols of data fields in accordance with the MCS of each terminal; dividing an area according to the number of terminals to which the data fields are to be simultaneously transmitted, if there are two or more selected terminals; and recalculating a reception signal to interference and noise ratio (SINR) for each area of each terminal, configuring a packet by resetting the MCS according to the recalculated SINR, and transmitting the configured packet.

Method for transmitting data in multi-user wireless communication system

Disclosed is an apparatus for receiving data in a communication system, including: a receiving unit configured to receive data transmitted from an access point (AP) by a multi-input multi-output (MIMO) scheme; a detecting unit configured to detect a data stream of the received data using an LQ decomposition scheme; a generating unit configured to generate channel information regarding the data stream; and a transmitting unit configured to feedback the channel information to the AP.

Apparatus and method for receiving data in communication system

An apparatus of transmitting a long training field includes: a station number determination unit configured to determine at least one station to be transmitted using transmission data or channel status information; a transmission stream allocation unit configured to determine the number of transmission streams for each of the least one station determined by the station number determination unit; a long training field number calculation unit configured to calculate the number of long training fields required for each of the at least one station determined by the transmission stream allocation unit and determines the least common multiple of the number of calculated long training fields of each station; and a long training field allocation unit configured to allocate the long training fields for each station to subcarriers allocated to each station to correspond to the least common multiple of the determined long training fields.

Method and apparatus for transmitting training sequence in multi user wireless communication system

A method for transmitting, by a transmitting terminal, data to a receiving terminal in a wireless communication system includes: generating a first detection field including symbols modulated by using a BPSK data tone; generating a second detection field including symbols modulated such that an even numbered subcarrier and an odd numbered subcarrier have a phase difference of 90 degrees; generating a data packet including the first detection field, the second detection field, and the data; and transmitting the data packet.

Method and apparatus for transmitting/receiving data in wireless communication system

A method for reducing power consumption in a wireless communication system includes: generating a descramble initial value by using at least some bits of identification information of an STA, which is known to an AP or base station and the STA; generating a first descramble sequence by using the generated descramble initial value and comparing at least some bits of the generated first descramble sequence with at least some bits of a service field of a currently-received signal; as the comparison result, when it is determined that the destination of the currently-received signal is not set to the STA, stopping the signal reception; and as the comparison result, when it is determined that the destination of the currently-received signal is set to the STA, generating a second descramble sequence by using the descramble initial value and descrambling the currently-received signal.

Method for reducing power consumption in wireless communication system

Provided a method for simultaneously transmitting data frames to a plurality of STAs in a multi-user based wireless communication system. The method includes: requesting sounding or feedback for the plurality of STAs by using a first control information frame containing first group information; receiving responses to the sounding or feedback request; reconfiguring the plurality of STAs composing the first group into a plurality of second groups on the basis of the responses such that the sum of maximum transport streams of the respective STAs composing one group becomes equal to or less than the maximum number of streams transmitted by an AP; transmitting a second control information frame containing second group information on the respective second groups to the plurality of STAs composing the first group; and transmitting data frames by using the second group information.

Method of transmitting data frame to multi-user in wireless communication systems

An apparatus and method for supporting access are provided. The method for supporting access in a wireless communication system includes: checking a plurality of stations (STA) which are to get access in a network and a plurality of access nodes of the respective STAs; determining the access priorities of the checked STAs and the priorities of the access nodes of the respective STAs; dividing a wireless resource and channel available in the network into multiple wireless resources and channels; and connecting the access nodes of the respective STAs to the multiple wireless resources and channels using a multi-channel media access control (MAC) protocol.

Apparatus and method for supporting access in wireless communication system

Provided is an apparatus and method for detecting reception signal symbol synchronization in a wireless communication system. The method, includes: calculating a channel power value in each of multiple antennas; selecting and averaging at least 2 channel power values; compensating carrier frequency offset for an average value; and determining a symbol boundary of a reception signal according to the size of the average value compensating the carrier frequency offset.

Apparatus and method for detecting reception signal symbol synchronization in wireless communication system

A cell search system for a mobile station in a time division duplex system includes: a primary synchronization code search module for searching primary synchronization codes and comparing frame values of the primary synchronization codes to determine a position of the maximum value; a correlation module for estimating a phase value and acquiring a first correlation value; a secondary synchronization code search module for generating determinative variables and storing them based on the position of the maximum value; a comparison and decision module for detecting a maximum value of the determinative variables, comparing it with the values stored in the secondary synchronization code search module to count matching values, and comparing the count value with a system value to decide whether slot synchronization and group acquisition is successful; and a base station determination module for determining a second correlation value between midamble codes and the received signals, and selecting a maximum value of it to determine a base station.

Cell search system for mobile station in time division duplex system and method for the same

Provided are an apparatus and method for providing a WLAN service using multiple channels. The wireless local area network (WLAN) service apparatus includes a service request receiver configured to receive service request information from a first wireless terminal accessed through a first channel, a data receiver configured to receive data from a first access point accessed through a second channel according to the service request information, a data transmitter configured to transmit the data to the first wireless terminal in a predetermined service area, and an access controller configured to control the first wireless terminal and the first access point to be accessed through different channels.

Apparatus and method for providing WLAN service using multiple channel

Provided is a transmitter and a receiver for a high-throughput wireless communication system. The transmitter includes a baseband transmitter, a DIF transmitter, and a RF transmitter. The baseband transmitter performs a MAC protocol process on transmission signals and reception signals and processes the transmission signals by dividing an entire transmission band into n bands in a physical layer process of the transmission data, where n is a natural number. The DIF transmitter combines transmission signals of each band from the baseband transmitter and outputs m channel signals corresponding to a number of transmission antennas, where m is a natural number. The RF transmitter modulates each of the channel signals transferred from the DIF transmitter and transmits the modulated signals through m antennas.

Transmitter and receiver for giga-bps high-throughput wireless communication system with multiple antennas and multiple bands

There is provided to a method for encoding an LDPC (Low Density Parity Check) code using the result of checking a previously specified parity, including the steps of: forming a parity bit check matrix having a dual diagonal structure consisting of (N-K) rows for check nodes and (N-K) columns on the basis of the H matrix; calculating the values of all the parity bits by inserting a given binary value in sub-blocks, with the parity bit check matrix formed on the H matrix; if the values of the parity bits are incorrect, checking the parity bit corresponding to the sub-block located in the last part of the H matrix; searching the parity bit parts where the parity bit check result is represented as '1'; performing an XOR operation in sub-blocks on the parity bit part obtained through a simultaneous equation between the parity bits of the searched parity bit parts and the parity bit parts; and determining the value of the parity bit satisfying the condition that the value obtained by multiplying the H matrix by a code word vector.

Method for encoding low density parity check codes using result of checking previously specified parity bits

Growing community of inventors

Daejeon, South Korea

Yu-Ro Lee