Samsung Electronics Co., Ltd.

Seoul National University

Byeong-Gi Lee

Jong-Hyung Kwun

Ho-Joong Kwon

Ok-Seon Lee

Eun-Yong Kim

Won-Hyoung Park

Seon-Wook Kim

Soo-Min Ko

An apparatus and a method for a random access scheme for multi-channel in a wireless communication system are provided. The method for performing the random access scheme for the multi-channel in the wireless communication system includes randomly generating a backoff counter value to transmit data; adjusting the backoff counter value by taking into account status of a plurality of idle subcarrier sets per backoff slot; when the backoff counter value becomes zero, selecting one or more subcarrier sets to carry the data from the idle subcarrier sets; and transmitting the data through the selected one or more subcarrier sets. The data collision probability between the terminals can be lowered, the channel utility can be enhanced, the transfer rate in the single-channel random access scheme can be raised, and the consumption of the radio resource can be reduced without using signals for the band request and allocation.

Apparatus and method for transmitting data in wireless communication system

A method and apparatus for selecting a retransmission mode in a MIMO communication system are provided wherein a receiver receives m initial transmission streams from a transmitter, m being an integer of 2 or larger, channel-decodes the m initial transmission streams and checking errors in the m channel-decoded streams, selects, if at least two channel-decoded streams have errors among the m channel-decoded streams, a retransmission mode to be used for the at least two streams having errors in the transmitter, and transmits information including the selected retransmission mode to the transmitter.

Method and apparatus for selecting retransmission mode in a MIMO communication system

A method for controlling power in a communication system. In the power control method, a transmitter receives feedback information from receivers located in its own cell; determines data rates of the receivers according to the received feedback information, calculates a load of the cell by calculating an amount of data to be transmitted to the receivers; and calculates transmission power of the transmitter by comparing the load of the cell with a threshold.

Method and system for controlling power in a communication system

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Seoul, South Korea

Byeong-Gi Lee