Electronics and Telecommunications Research Institute

Samsung Electronics Co., Ltd.

Yonsei University

Young Seog Song

Dong Seung Kwon

Jun Hwan Lee

Byung-Jae Kwak

Ji Hyung Kim

Seung Joon Lee

Choongil Yeh

Wooram Shin

Moon Sik Lee

Choong Il Yeh

Il Gyu Kim

Jin-Woo Kim

Seung Chan Bang

Eun-Young Choi

Eun Young Choi

Chung Gu Kang

Juho Park

Min Sik Seo

Jiwon Kang

Young Jo Ko

Bum-Soo Park

Seung Eun Hong

Chungyong Lee

DongSeung Kwon

Jung-Hyun Kim

In-Kyeong Choi

Ji Won Kang

Chung Yong Lee

Jihyung Kim

Seung Nam Choi

Ji Hung Kim

Hong-Yeop Song

Joonwoo Shin

Joondoo Kim

Kyung Sik Seo

Ii Gyu Kim

Song Noh

Joon-doo Kim

Mi-Young Nam

Joon Doo Kim

A method of estimating a channel of a base station in a communication system using an IRS may comprise: receiving a first signal through a direct path between a terminal and the base station from the terminal and a second signal through an indirect path through the IRS from the terminal; estimating a first angle of arrival of the second signal received from the IRS; estimating a second angle of arrival of a signal transmitted to the IRS by the terminal based on the estimated first angle of arrival; estimating a third angle of arrival of the first signal received from the terminal based on the estimated first angle of arrival; and estimating path gains on the direct path and the indirect path based on the estimated first angle of arrival to the estimated third angle of arrival.

Method and apparatus for estimating channel in communication system

Provided is a method for feeding back a channel quality indicator (CQI) by a terminal. The terminal receives, from a base station, at least one reference signal through at least one of multiple beams of the base station. The terminal measures a signal-to-interference plus noise ratio (SINR) for the at least one reference signal. The terminal determines a first level corresponding to the measured SINR among levels of a first CQI. In addition, the terminal feeds back the first CQI having the first level to the base station.

Scheduling method and apparatus of multi-antenna communication system, and method and apparatus for feeding-back channel quality indicator

There are provided an antenna apparatus and a method of handover using the antenna apparatus. The antenna apparatus may comprise a plurality of antenna elements forming a plurality of beams in a predetermined service area. The plurality of antenna elements are arranged in a plurality of rows, and a number of antenna elements included in an uppermost row of the plurality of rows is smaller than a number of antenna elements included in a downmost row of the plurality of rows, and differences between center angles of beams formed by the antenna elements included in the downmost row are larger than differences between center angles of beams formed by the antenna elements included in the uppermost row.

Antenna apparatus and method for handover using the same

A method in which a base station transmits pilot signals in a multiple-antenna communication system is provided. The base station includes some of the plurality of pilot signals distinguished by at least one of time domain symbols, subcarriers, and orthogonal codes in a first set to which a first random number is applied. The base station includes the remaining pilot signals, excluding the pilot signals that are included in the first set, in a second set that uses the same resources as used by the first set and to which a second random number different from the first random number is applied. The base station transmits at least one of the pilot signals that belong to the first set and the second set.

Method and apparatus for transmitting pilot in multi-antenna communication system, and method and apparatus for allocating pilot in multi-antenna communication system

In a communications system using a plurality of beams, a terminal determines a beam to be communicated with the terminal among the plurality of beams, determines one sequence among sequences allocated to the determined beam as a beam based random access preamble, and transmits the beam based random access preamble through the determined beam. In addition, if a random access response for the beam based random access preamble is not received from a base station for a set interval, the terminal determines one sequence among sequences in a cell based random access preamble collection as a cell based random access preamble and transmits the cell based random access preamble.

Method and apparatus for random access in communications system

Disclosed herein relates to a resource allocation method for a machine type communication (MTC) device. The resource allocation method for the MTC device includes allocating a control channel with respect to a user terminal to a first time domain of a sub frame, and mixing at least one of a control channel with respect to the at least one MTC device, a data channel with respect to the user terminal, and a data channel with respect to the MTC device in a second time domain of the sub frame, and allocating the mixed channel to the second time domain of the sub frame. Accordingly, in a wireless communication system, control information and data may be transmitted and received to and from the MTC device while maintaining compatibility with the user terminal.

Method and apparatus of resource allocation for machine type communication device, method and apparatus for receiving data for machine type communication

Disclosed are a method for generating a random access signal of a machine type communication (MTC) device using a narrow bandwidth, and an MTC device. The method generates a random access signal by allocating a position in a frequency domain of a random access signal dedicated to the MTC device, that is, a position of a frequency for transmission of a random access preamble, to a center position of a base station system bandwidth, or by shifting a center frequency of the MTC device to a position of a random access frequency allocated for a legacy LTE terminal by a base station.

Method for generating random access signal of machine type communication device using narrow bandwidth

In a method of mitigating inter-cell interference, terminals are grouped into groups. A base station transmits data to a first terminal belonging to a first group among the groups, without cooperation with a neighboring base station. The base station transmits data to a second terminal belonging to a second group among the groups, through cooperation with the neighboring base station.

Inter-cell interference relief method

A mobile station includes a plurality of mobile station antennas that receive at least one independent training signal from a plurality of base station antennas, and estimates a downlink channel formed by each of a plurality of base station antennas and each of the mobile station antennas by using the at least one independent training signal. The mobile station generates a beam vector by using the downlink channel, and forms transmission beams in the plurality of mobile station antennas for transmitting a signal to an uplink.

Beamforming method using multiple antennas

A device for generating a transmission codebook in a communication system including a multi-input multi-output (MIMO) antenna according to an embodiment of the present invention includes: a frequency determiner that determines a frequency to allow the transmission codebook to have an optimal characteristic; a precoding matrix generator that generates a precoding matrix on the basis of the frequency; and a codebook generator that generates a retransmission codebook to be used for retransmission on the basis of the precoding matrix and generates the transmission codebook on the basis of the retransmission codebook.

Device for generating codebook, method for generating codebook, and method for transmitting data

In an orthogonal frequency division multiple access (OFDMA) communication system, a transmission apparatus connects multiple tiles, which have a 4&#xd7;3 structure, along a time or frequency axis in an uplink 4-layer partial usage of subchannels (PUSC) mode, and designs pilots corresponding to one layer at one of multiple symbol positions adjacent to a first corner of the tiles and one of multiple symbol positions adjacent to a second corner of the tiles that face the first corner in a diagonal direction. In this case, null symbols are designed at the rest of the symbol positions adjacent to the first corner or the second corner where the pilots are not designed. Accordingly, a receiving apparatus can obtain n channel values from n tiles. Further, n estimated channel values are applied to a linear interpolation method, so that it is possible to estimate the entire channel value of n tiles.

Pilot design method, recording medium, and transmission apparatus

Provided are a transmitting apparatus and a transmitting method in a multiple input multiple output system. A power allocation controller includes a block Tomlinson-Harashima precoder (BTHP) that precodes and outputs data to be transmitted to each user in a nonlinear scheme. The BTHP removes and outputs inference signals from data for each user based on the channel information that is fed back from the users. The data for each user output from the BTHP are allocated with power by the power allocation controller. The power allocation controller calculates power allocation parameters so that receiving minimum distances at receiving ends for each user that receive data through the MIMO antennas are the same, and allocates the calculated parameters to data for each user.

Transmitting apparatus in multiple input multiple output system

A method for a transmitting terminal in a multi-user multi-antenna environment to perform precoding includes: receiving feedback information from a plurality of receiving terminals; estimating a channel between the transmitting terminal and the plurality of receiving terminals by using the feedback information; and generating a plurality of transmission symbols by applying a first nonlinear precoding method and a second nonlinear precoding method to a plurality of symbols and the estimated channel to be transmitted to the plurality of receiving terminals. The first nonlinear precoding method is used to eliminate interference between subchannels of the same receiving terminal, and the second nonlinear precoding method is used to eliminate interference between the receiving terminals.

Precoding method and device

A method for controlling transmission power of a base station in a cellular system includes: receiving a reference signal from at least one neighbor base station that is located around the base station; estimating a radio environment between the base station and the neighbor base station by using the receiving power of the reference signal; and controlling cell coverage of the base station by determining the transmission power based on the radio environment.

Method for controlling transmission power in cellular system

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Daejeon, South Korea

Young Seog Song