Lg Electronics Inc.

Sungkyunkwan University

Jongyeol Ryu

Hanbyul Seo

Wan Gyun Choi

Dongin Kim

Byounghoon Kim

Hojin Song

Disclosed is a method of controlling, by a device, power for guaranteeing the quality of service of a device to device (D2D) direct communication. In detail, the method comprises the steps of: receiving, from a base station, information containing at least one of channel information and information of a receiving side device in a D2D communication; estimating an uplink channel with the base station on the basis of the received information; and selecting a transmission power by comparing the channel gain value of the uplink channel with a threshold value for determining the maximum transmission power, and transmitting data to the base station using the selected transmission power, wherein the channel information comprises at least one of channel information of the D2D communication, uplink channel information between the device and the base station, and interference channel information between the device and the receiving side device in the D2D communication.

Power control method for guaranteeing quality of service of device to device direct communication and apparatus therefor

Disclosed is a method in which a base station (BS) transmits information to a plurality of terminals in a wireless communication system. Specifically, the method comprises the steps of: dividing the plurality of terminals into two or more groups according to a channel state of each of the BS and the plurality of terminals and a channel state between the plurality of terminals; and broadcasting the information to a first group among the two or more groups, wherein the first group transmits the information to another group among the two or more groups through D2D communication.

Broadcasting method using device-to-device (D2D) communication in wireless communication system

Disclosed are a method for transmitting and receiving data in a wireless access system supporting relay nodes, and an apparatus for same. In particular, the present invention comprises: a broadcast phase for receiving an acknowledgement (ACK) signal from a first terminal and a negative acknowledgement (NACK) signal from a second terminal, after a base station transmits first data to the first terminal by using a first precoding vector (w1, B), and second data to the second terminal by using a second precoding vector (w2, B); a listening phase for receiving an ACK signal from the first terminal and a NACK signal from the second terminal, after the base station transmits second data to the first and second terminals by using a third precoding vector (wL); and a cooperative phase for the base station to transmit the second data to the second terminal, in cooperation with the first terminal, by using a fourth precoding vector (wC) which has been chosen for maximizing the transmission efficiency of the second terminal, wherein the first precoding vector, the second precoding vector, and the third precoding vector are chosen so that the total length of the rounds of all phases is minimized.

Method for transmitting and receiving data in wireless access system and apparatus for same

Disclosed are a method for transmitting and receiving data in a wireless access system supporting relay nodes, and an apparatus for same. In particular, the present invention comprises the steps of: sending a request for a retransmission to an adjacent second terminal, in case the recovery of data from a first signal received from a base station fails due to interference by the second terminal adjacent to a first terminal; the first terminal receiving a second signal from the second terminal; and the first terminal recovering data from the first signal, using the second signal, wherein the base station schedules a terminal other than the first and second terminals at the point of transmitting the second signal.

The present invention relates to a method for determining a precoding matrix for downlink signal transmission in a base station cooperative wireless communication system. The method includes receiving from a first terminal first channel information between the first base station and the first terminal, and second channel information between a second base station and the first terminal, transferring the first and the second channel informations to the second base station, determining a first precoding matrix for a first channel maximizing the efficiency of transmission to the first terminal, and determining, by the second base station, a second precoding matrix for a third channel between the second base station and the first terminal in order for a signal transmitted from the second base station to the first terminal to be arranged in an area where a signal transmitted from the first base station to the first terminal is not used.

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Daejeon, South Korea

Jongyeol Ryu