Abstract: Disclosed is a method for transmitting and receiving a signal in a communication system, and a system for supporting the method. To this end, a first communication system transmits data during a first time slot and receives data during a third time slot, and a second communication system, differing from the first communication system, transmits data during a second time slot and receives data during a fourth time slot. The first and second time slots are defined by downlink frame transmission intervals which exist in the entire frame transmission interval allocated for the first communication system, and the third and fourth time slots are defined by uplink frame transmission intervals which exist in the entire frame transmission interval allocated for the first communication system, wherein the first to fourth time slots do not overlap each other.

Abstract: A method for transmitting/receiving data in a communication system using multiple frequency bands. The transmission method includes fragmenting a desired transmission Service Data Unit (SDU) in units of Packet Data Units (PDUs); and transmitting the fragmented PDUs over at least two frequency bands among the multiple frequency bands. Each of the multiple frequency bands is supported by a system having backward compatibility with a legacy system. The reception method includes decrypting a wireless resource (MAP) allocated separately for each of the frequency bands to extract fragment information therefrom; and receiving PDUs over the frequency bands separately, and restoring the SDU according to fragment information corresponding to the corresponding frequency band.

Abstract: Disclosed is a method for controlling transmission power to be allocated to sub-carrier signals in a cellular communication system capable of dividing a frequency band into a plurality of sub-carrier bands and multiplexing the sub-carrier signals of the sub-carrier bands based on multiple frequency reuse factors.

Abstract: An apparatus and method for controlling an UpLink (UL) load in a broadband wireless communication system are provided. The apparatus includes a determining unit for determining a resource amount to be allocated to each of a plurality of Mobile Stations (MSs) and a Modulation and Coding Scheme (MCS) level to be applied to each MS, an estimator for estimating a load of each MS by using the resource amount and the MCS level and a controller for controlling the resource amount and the MCS level such that the load of each MS does not exceed a first threshold. By determining and controlling the resource amount and MCS level, the apparatus and method reduce interference to a neighboring cell in a broadband wireless communication system.

Abstract: Provided is an apparatus and method for transmitting a channel sounding signal from a user terminal in a multiple antenna system. In the method, a channel for each of a plurality of antennas is estimated. The receiving signal power of each of the antennas is calculated using the channel information obtained through the channel estimation. The antenna with the highest RX signal power is selected. Therefore, it is possible to enhance the signal reception performance of the user terminal.

Abstract: An apparatus for transmitting/receiving a signal in a communication system is provided. A Mobile Station (MS) spreads a transmission signal to generate a spreading signal, receives, from a Base Station (BS), information on a second spreading signal transmission region, extended from a first spreading signal transmission region, and maps the generated spreading signal to a subcarrier in the second spreading signal transmission region. A Base Station (BS) transmits information on a second spreading signal transmission region extended from a first spreading signal transmission region, for reception of a spreading signal, receives a spreading signal mapped to subcarriers over the second spreading signal transmission region, from an Mobile Station (MS), detects a spreading signal from the spread signal mapped to the subcarriers, and despreads the detected spreading signal to restore a transmission signal.

Abstract: A method of allocating sub-channel signal interleaving patterns to BSs forming a wireless communication system that divides a frequency band into a plurality of sub-carriers and including a plurality of sub-channels, which are a set of predetermined adjacent sub-carriers. The method includes: creating a basic orthogonal sequence having a length identical to a number of the sub-carriers forming the sub-channel; creating a plurality of sequences having a same length as the basic orthogonal sequence by cyclic-shifting the basic orthogonal sequence a predetermined number of times or performing a modulo operation based on a number of the sub-carriers forming the sub-channel, after adding a predetermined offset to the cyclic-shifted basic orthogonal sequence; selecting a predetermined number of sequences corresponding to a number of the BSs from among the plurality of sequences; and allocating the selected sequences as the sub-channel signal interleaving patterns for the BSs.

Abstract: A preamble generation method and apparatus are provided for improving transmit diversity by changing a preamble structure in a broadband wireless communication system using multiple antennas based on a multiple input multiple output (MIMO) scheme. First pilot tones associated with different antennas are selected. The first pilot tones are multiplied by different first Walsh codes. Second pilot tones associated with the same antenna are sequentially selected along a frequency axis. The second pilot tones are multiplied by a second Walsh code. Preambles are generated by assigning, to at least two symbol durations, output signals multiplied by the first and second Walsh codes. Consecutive pilot tones during each of the at least two symbol durations are spaced by one pilot tone, and code streams of the first and second Walsh codes are alternately multiplied by the pilot tones. The preamble structure has orthogonality between the antennas using frequency, time and code domains.

Abstract: Disclosed is an apparatus for determining transmit power of an uplink frame transmitted from a subscriber station to a base station and transmitting data in a mobile communication system in which a downlink frame, transmitted from the base station to the subscriber station, and the uplink frame are time division-duplexed (TDD). The apparatus includes a receive power measurement unit for measuring receive power of signals received from the base station; a transmit power controller for determining the transmit power of the uplink frame from the receive power measured by the receive power measurement unit and information related to receptions of an uplink frame, which is received from the base station; and a transmission radio frequency processor for performing radio processing so that the uplink frame is transmitted according to the transmit power determined by the transmit power controller.

Abstract: Provided are an apparatus and method for canceling interference in a Broadband Wireless Access (BWA) system. The method includes estimating channel coefficient vectors of a plurality of Mobile Stations (MSs) using the same resource; computing a correlation matrix by subtracting a channel coefficient vector of a corresponding MS from a specific tone input vector within the same resource and by auto-correlating the subtracted vector; canceling interference from the data-tone input vector and the channel matrix by using the correlation matrix; and estimating a transmission symbol for each MS by performing Multiple Input Multiple Output (MIMO) detection by using the interference-cancelled input vector and the interference-cancelled channel matrix.

Abstract: Based on a selected criterion, a BTS (Base Transceiver Station) for each mobile station (MS) determines an antenna pattern in a reverse channel, based on combined weight factors in weighed combining of signals from antenna array elements during MS signal receiving, and in the forward channel, based on combined weight factors in weighed combining of signals from antenna array elements during MS signal transmission. The antenna pattern determined in the forward channel is performed by the reverse channel signal. The antenna pattern determined in the forward channel is based on the estimate of the angle signal area of mobiles station that is the average angle of signal arrival and its angle sector or on the estimate of average angle of signal arrival only. To determine the desired signal angular area, a decision function is proposed, where powerful interference canceling is implemented.

Abstract: Disclosed are a system and a method of allocating frequency resource in a cellular communication system. The method includes the steps of dividing a predetermined time duration into at least two sub-time durations, and forming the frequency resource by applying mutually different frequency reuse factors to the sub-time durations.

Abstract: A method for controlling power in a communication system. The power control method in a base station includes receiving channel information from a plurality of mobile stations, and generating power control information of the mobile stations according to the received channel information; mapping the generated power control information to transmission fields of corresponding mobile stations according to allocation information of channels allocated to receive the channel information; and broadcasting to the mobile stations a message including the power control information mapped to the transmission fields of the corresponding mobile stations.

Abstract: A method for transmitting reference signals in a radio communication system in which a frequency band is divided into a plurality of sub-frequency bands. The reference signals are transmitted through at least one of the plurality of sub-frequency bands, and data signals are transmitted through the plurality of sub-frequency bands except for the at least one of the plurality of sub-frequency bands. The method includes the steps of: determining a reference signal pattern representing positions of the at least one of the plurality of sub-frequency bands through which the reference signals are transmitted in consideration of a preset time and a preset bandwidth; generating the reference signals using a PN code and a Walsh code; and transmitting the reference signals through the sub-frequency bands corresponding to the reference signal pattern.

Abstract: Disclosed is a method for handing-off a mobile station receiving packet data over a second channel from a first base station system (BSS) to a second BSS by a base station controller (BSC) in a system in which the mobile station communicates with the first BSS and the second BSS adjacent to the first BSS through a first channel for transmitting a control message, and the mobile station communicates with the first BSS through the second channel for transmitting the packet data. In the method, the mobile station measures receiving strengths of pilot channels transmitted from the first BSS and the second BSS, and transmits the measured receiving strengths to the BSC through the first BSS and the second BSS. The first and second BSSs each calculate available transmission power allocable to the second channel and transmits the calculated available transmission power to the BSC.

Abstract: An apparatus for controlling a gain of transmit antennas in a communication system. The transmit antenna gain control apparatus includes a controller for determining a gain of multiple transmit antennas on a basis of a transmit antenna having a minimum currently unused residual power among currently unused residual powers of the multiple transmit antennas used in the communication system.

Abstract: An apparatus and method for transmitting data in a communication system are provided. The method for transmitting the data includes determining data to be transmitted over a power boosting zone, generating a power boosting zone used for power-boosting and transmitting the data, allocating the data to the generated power boosting zone and power-boosting and transmitting the power boosting zone.

Abstract: A method and apparatus for receiving data in a communication system is disclosed. Receiving a first signal from a transmitter, a first canceller cancels from the received first signal a second signal desired to be received from the transmitter. A second canceller detects and cancels an interference signal from the second signal-canceled first signal. A calculator calculates a Log Likelihood Ratio (LLR) of the interference signal-canceled first signal.

Abstract: An apparatus and method for canceling narrow-band interference in a wideband mobile communication system. The apparatus includes a down converter for down converting a received signal into a baseband signal, an analog-to-digital converter for converting the baseband signal into a digital signal, a decimation filter for decimating the digital signal according to a decimation ratio, an interference canceller for detecting narrow-band interference signals contained in an output of the decimation filter, and canceling the narrow-band interference signals, and a demodulator for demodulating an output of the interference canceller.

Abstract: Control information communicating apparatus and method in Broadband Wireless Access (BWA) system are provided. A Base Station (BS) includes a manager for managing UL control region allocation information of adjacent BSs; a scheduler for scheduling resources and controlling periodic transmission of UL control region allocation information when a UL control region of the BS is the same as UL control regions of the adjacent BSs; and a control information generator for periodically generating the UL control region allocation information under the control of the scheduler.