Abstract: Provided is a method performed in a terminal for processing an interest message. The method includes receiving a message from a message server after a login event for a user of the terminal occurs, wherein the login event is related to a message service provided by the message server; storing, in response to determining that the received message corresponds to an interest message of the user, the received message in a local storage of the terminal; receiving a search request for the interest message of the user; and searching and providing the interest message of the user through the local storage of the terminal in response to the search request.

Abstract: An apparatus and method for determining a transmission unit for data stream transmission in a wireless communication system in which multiple transmission and reception antennas are used and a receiver provides information on a data stream to be transmitted through a transmission unit. A fading estimator calculates fading values from the multiple transmission antennas to the multiple reception antennas. A channel quality estimator reverse-orders combined weights for multiple transmission units based on the fading values from the multiple transmission antennas to the multiple reception antennas, successively selects transmission units for data stream transmission among the reverse-ordered transmission units, determines a modulation and coding scheme (MCS) for each of the selected transmission units, and feeds back the MCS to a transmitter.

Abstract: An apparatus and method for determining a transmission unit for data stream transmission in a wireless communication system in which multiple transmission and reception antennas are used and a receiver provides information on a data stream to be transmitted through a transmission unit. A fading estimator calculates fading values from the multiple transmission antennas to the multiple reception antennas. A channel quality estimator reverse-orders combined weights for multiple transmission units based on the fading values from the multiple transmission antennas to the multiple reception antennas, successively selects transmission units for data stream transmission among the reverse-ordered transmission units, determines a modulation and coding scheme (MCS) for each of the selected transmission units, and feeds back the MCS to a transmitter.

Abstract: A transmit diversity apparatus and method are provided for adaptively providing a transmit diversity gain or a beamforming gain depending on changes in a radio channel undergoing multipath fading in a mobile communication system using multiple antennas. A transmitter forms as many fixed beams as the number of transmit antennas and a receiver selects a fixed beam having relatively high power among received fixed beams or linearly combines the received fixed beams. This common eigen space transmit diversity scheme improves the link performance between the transmitter and the receiver.

Abstract: An apparatus and a method for transmitting and receiving data in a mobile communication system including an array antenna. The method includes the steps of transmitting pilot channels through a transmission antenna while aligning the pilot channels orthogonally to each other, receiving feedback information related to the pilot channels from a mobile station capable of receiving the data, dividing the data to be transmitted into sub-data streams by using the feedback information, and determining a coding rate and a transmit power for the sub-data streams, and converting the sub-data streams into symbol arrays to be transmitted according to the coding rate and the transmit power and transmitting data by converting the data into fixed beams.