Electronics and Telecommunications Research Institute

University-industry Cooperation Group of Kyung Hee University

Jin Soo Wang

Sung-Hyun Hwang

Yun Hee Kim

Jae Cheol Park

Jae Chul Park

Provided is a transmitter for transmitting an orthogonal frequency division multiplexing (OFDM) signal using multiple antennas, including: a subgroup generator to divide data symbols of a frequency domain into a plurality of subgroups; an inverse fast Fourier transform (IFFT) unit to perform an IFFT with respect to each of the subgroups so as to generate partial signals of a time domain corresponding to the plurality of subgroups, respectively; a candidate OFDM signal generator to generate at least two candidate OFDM signals using a combination of the partial signals so that each of the partial signals is transmitted to one of transmit antennas; and a selector to select one of the at least two candidate OFDM signals.

Method of transmitting and receiving orthogonal frequency division multiplexing (OFDM) signal using multiple antennas, and transmitter and receiver thereof

A method and apparatus for adaptively transmitting the same data, i.e., multicast/broadcast data, according to channel quality to a receiving group including one or more terminals that request the same service in a wireless network. A base station obtains feedback on channel quality indications (CQIs) from a plurality of terminals, selects a transmission technique that satisfies desired service quality based on the CQIs, and transmits data to the terminals included in a receiving group by using the selected transmission technique. The CQIs to be transmitted from the terminals in the receiving group to the base station are transmitted through a previously allocated common CQI feedback channel. In the present invention, in order to reduce a CQI feedback channel capacity, the base station does not allocate a common CQI feedback channel with respect to each reception terminal and allocates radio resources according to CQI levels. As radio resources are allocated according to CQI levels, a CQI feedback channel capacity may not be increased even when the number of terminals in the receiving group is increased and adaptive transmission may be efficiently performed.

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Busan, South Korea

Jin Soo Wang