Abstract: An apparatus and method are provided for stabilizing terminal power in antenna ports. A data transmission/reception method is provided for terminal power stabilization in a communication system using multiple antennas. An optimal antenna immune to absorption loss due to human body proximity is selected from among multiple antennas connected to a single port when a data service is provided. Data for the data service is transmitted and received through the selected antenna.

Abstract: A method and an apparatus for controlling call admission in an OFDM mobile communication system are provided. Upon receipt of a call admission request, it is determined whether a requested call is a handoff call or a new call and the traffic service type and QoS level of the requested call are determined. The amount of resources required for the call is calculated using the QoS level and the amount of resources of on-going calls is calculated according to the traffic service type. The amount of available resources in a cell is calculated using the amount of resources of the on-going calls and it is determined whether to admit the call by comparing the available resource amount with the required resource amount.

Abstract: An apparatus and method for controlling power in a multi-hop relay broadband wireless communication system are provided. A BS sends a signal to an RS and an MS to estimate distances between the BS, the RS and the MS. Upon receipt of signals from the RS and the MS, the BS measures ToAs of the received signals and detects time information included in the received signals, and calculates propagation delays between the BS, the RS and the MS based on the ToAs and the time information. The BS estimates the distances between the BS, the RS and the MS using the propagation delays, and controls transmission power according to the estimated distances.

Abstract: A frequency resource operating apparatus and method for transmitting and receiving data at a different hopping pattern speed according to a CSI in a BWA communication system are provided. In a method of transmitting and receiving data using CSI in a mobile communication system, a BS sets the CSI of an MS to an initial CSI and sends data to the MS according to the initial CSI. The MS sends a downlink CSI to the BS. The BS groups the MS based on the downlink CSI and sends data to the MS according to a hopping pattern for the group of the MS among hopping patterns preset for predetermined groups.

Abstract: A subcarrier assignment apparatus and a subcarrier assignment method, in which each of a plurality of Base Stations (BSs) constituting an Orthogonal Frequency Division Multiple Access (OFDMA) communication system provides services in the capacity of a serving BS to Mobile Stations (MSs). Channel quality information for the respective MSs are fed-back from the respective BSs. Subcarriers are assigned to the respective MSs according to a corresponding scheduling scheme in consideration of the channel quality information for the respective MSs, which are fed-back from the respective BSs, and then BSs which manage the subcarriers assigned to the respective MSs according to the corresponding scheduling scheme are selected. These operations provide site diversity to each of the MSs, and thus system capacity is maximized.

Abstract: A frame configuration method and apparatus for sending data via an RS in a broadband wireless communication system are provided. In the reception mode, the RS monitors reception of data in an (n?1)th frame from an MS and reception of data in an nth frame from a BS. The RS classifies the data received from the MS and the data received from the BS as combinable data to be sent in combination or as non-combinable data to be sent separately, and stores the classified data distinguishably. When the RS transitions to a transmission mode, it determines whether to XOR-operate or mask the stored data. If the stored data can be masked, the RS XOR-operates the stored data and sends the masked data to the BS and the MS.

Abstract: Provided is an apparatus and method for communicating a frame in a multi-hop relay cellular communication system. When communicating at a Relay Station (RS), a Downlink (DL) signal is received from a Base Station (BS) and the received DL signal is reconfigured during a first section of a frame. The reconfigured DL signal is transmitted to a Mobile Station (MS) during a second section of the frame. During a third section of the frame, a UL signal is received from the MS and is reconfigured. The reconfigured UL signal is transmitted to the BS during a fourth section of the frame. The RS recovers data from the BS to retransmit only specific data corresponding to the BS. Accordingly, unnecessary retransmission can be prevented and thus resources can be used efficiently.

Abstract: A method for transmitting a signal by a transmitter in a frequency overlay communication system. The method includes generating y first signal groups by shuffling input information data with a length yN on an N-by-N grouping basis according to a first shuffling scheme; generating y second signal groups by performing N-point IFFT on each of the first signal groups; generating y third signal groups by multiplying each of the second signal groups by preset values; generating N fourth signal groups by de-shuffling the third signal groups on a y-by-y grouping basis according to a de-shuffling scheme; generating N fifth signal groups by performing y-point IDFT on each of the fourth signal groups; generating y sixth signal groups by shuffling the fifth signal groups according to a second shuffling scheme, and serial-converting the sixth signal groups; and performing a transmission RF process on the serial-converted signal and transmitting the RF-processed signal to a receiver.

Abstract: An apparatus and a method for selecting an antenna appropriate for a data service type in a communication system employing multiple antennas. The method of performing data communication through a transceiver using multiple antennas includes determining the type of the data services contained in a received signal, selecting one of the multiple antennas with a communication quality corresponding to the type of the data services, and employing the selected antenna to perform the data communication.

Abstract: A frame communication apparatus and method for a broadband wireless communication system are provided that employ a transmitter. In the transmitter, a control channel generating unit generates burst allocation information including a receiver identification (ID) with respect to a transmission packet, a burst generating unit constructs data burst by adding a header including a traffic ID to the transmission packet, and a transmitting unit transmits the burst allocation information and the data burst. An existing connection ID (CID) is subdivided into a user ID (UID) and a traffic ID (TID). The UID and the TID are recorded in a map channel message and a medium access control (MAC) header, respectively. Accordingly, an amount of information contained in a downlink map (DL-MAP) and uplink map (UL-MAP), and an amount of the MAC header of a data packet can be reduced.

Abstract: An apparatus and method for providing EPG in a digital broadcasting system, in which an EPG connecting unit connects EPG servers of digital broadcasting channels, a program information generating unit generates program information according to program characteristics of the digital broadcasting channels, and an EPG server generates EPG information using the generated program information, and combines the generated EPG information with EPG information of the broadcasting channels. Accordingly, the program information of different broadcasting channels can be searched without switching channels, and quality of the EPG service can be improved. Moreover, users can be allowed to personally configure the EPG, thereby providing the EPG according to characteristics of the users.

Abstract: A system for performing cell acquisition in a frequency overlay communication system having a first frequency band and a second frequency band including the first frequency band. A base station (BS) generates a reference signal used for identifying a cell using a specific sequence in a predetermined frequency band, and transmits the reference signal. A mobile station (MS) receives the reference signal to determine whether the BS uses the first frequency band or the second frequency band, determines a reference signal having a maximum correlation value through correlation calculation with at least one predefined sequence, and detects a BS identifier (ID) corresponding to the determined reference signal.

Abstract: A ranging apparatus in a communication system is provided. A terminal generates a ranging code for ranging with a base station, maps the ranging code to at least one sub-carrier so the ranging code is repeated in a time domain, generates a ranging signal so the mapped ranging code has a size of one symbol interval, and transmits the generated ranging signal to the base station. The base station receives a ranging signal, extracts a half signal of a valid symbol interval of the ranging signal, generates a valid symbol interval signal by repeating the extracted half signal of the valid symbol interval, restores a ranging signal using the valid symbol interval signal, and performs ranging using the ranging signal.

Abstract: An apparatus and method for reducing transmission overhead in a broadband wireless communication system are provided. In a transmitter in a broadband wireless communication system where total time resources are divided according to lengths of transmission data and the transmission data are allocated to the divided time resources, a header generator generates a header including data allocation information and control information for a frame to be transmitted, and a traffic channel constructer constructs a traffic channel by combining the header with a burst.

Abstract: A method is provided for performing handoff in a communication system including a serving base station (BS) in communication with a mobile station (MS), at least one neighbor BS using a communication scheme different from a communication scheme of the serving BS, and the MS capable of communicating with the neighbor BS. The method includes compensating a signal strength of one of the serving BS and the neighbor BS, received at the MS, such that handoff decision is possible, and determining whether to perform a handoff of the MS, using the compensated signal strengths.

Abstract: An apparatus and method for providing subscriber information in a mobile communication system are provided. A database stores registered information containing subscriber information, a scope of persons to view the subscriber information, and an open level for the subscriber information. A wait time information management server stores the subscriber information in the database. Upon request for a call from a calling terminal, the wait time information management server searches for the subscriber information in the database and provides the searched subscriber information according to the open level to an MSC. The MSC sends wait time information based on the subscriber information received from the wait time information management server to the calling terminal.

Abstract: A transmitting/receiving apparatus and method in a mobile communication system are provided. In a transmitter, an encoder encodes input information data and outputs systematic bits on a first channel and redundancy bits on a second channel. A first channel interleaver interleaves the systematic bits and a second channel interleaver interleaves the redundancy bits. A modulator maps one channel data of I and Q channel data, received from the first channel interleaver and another channel data of the I and Q channel data, received from the second channel interleaver to a modulation symbol using different mapping rules for I and Q channels.

Abstract: There is provided a transmitting apparatus in a broadband wireless communication system in which a control channel generator generates a control channel that includes an user information and a resource group information allocated to the user based on position and number of at least one predetermined resource unit included in the resource group which consists of at least one predetermined resource unit and a channel generator for allocating the data to resources according to the control channel, and a method thereof. Also, there is provided a receiving apparatus in response to the transmitting apparatus and a method thereof.

Abstract: An apparatus and method for reducing pilot overhead in a broadband wireless communication system are provided. A data symbol mapper maps data symbols to be transmitted into subcarriers and detects values of the data symbols mapped into predefined subcarriers. A pilot generator determines masking codes for each pilot group by using the detected values of the data symbols and masks the determined masking codes into pilot symbols of the corresponding pilot group. A pilot symbol mapper maps the masked pilot symbols received from the pilot generator into subcarriers.

Abstract: A method for performing an initial operation of a mobile station (MS) that uses a first frequency band, in a frequency overlay communication system having the first frequency band including a plurality of sub-frequency bands. The method includes performing correlation on a full frequency band in units of the first frequency band, receiving broadcast information through a frequency band having a maximum correlation value, and performing an initial access to a base station (BS) through the frequency band having the maximum correlation value if a frequency bandwidth of the BS acquired from the broadcast information is narrower than or equal to a selected frequency bandwidth of the MS.