Abstract: A method and system for configuring a frame in a communication system is provided.

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: An apparatus and method for generating subchannels in a communication system are provided. An apparatus and method of the invention includes a Base Station (BS) in which the BS groups J slots included in a subchannel generation zone into I groups, selects, from the J slots, M band-Adaptive Modulation and Coding (AMC) slots with which it will generate a band-AMC subchannel, selects (J-M) slots as diversity slots with which it will generate a diversity subchannel, generates the band-AMC subchannel using the M slots and generates the diversity subchannel using the (J-M) slots.

Abstract: A method and system for controlling power in a communication system are provided, in which a base station calculates a power control value for an mobile station based on feedback information received from the mobile station, transmits power control information including the power control value to the mobile station, measures the strength of a signal received corresponding to the transmit power control information from the mobile station, determines the status of the mobile station using the signal strength and the power control value, and schedules the mobile station according to the determination.

Abstract: Provided is an apparatus and method for increasing the service coverage area of a broadcast channel in a wireless communication system by using a Hybrid Automatic Repeat reQuest (HARQ) scheme. The method receives a MAP message including information about the type of a Media Access Control (MAC) management message transmitted in the current frame and information about retransmission of the MAC management message. Upon receipt of the MAC management message, based on the received information, the method combines the received MAC management message with a MAC management message that is stored in a buffer, wherein the MAC management message that is stored in the buffer was stored due to a reception error.

Abstract: In a control method of a communication system, a Base Station (BS) receives noise and interference information from at least one neighboring BS in charge of a neighboring cell being adjacent to a serving cell of the BS, calculates a control value of Mobile Stations (MSs) located in the serving cell according to the received noise and interference information, and generates control information according to the calculated control value, and transmits the generated control information to the MSs.

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 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 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 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: An apparatus and method for transmitting/receiving a multi-functional preamble signal in a wireless communication system are provided. In an apparatus for transmitting a preamble signal in a wireless communication system, a first generator generates a predetermined ZAC sequence. A circular shifter circular-shifts the ZAC sequence according to a BS ID. A second generator generates a sequence in which samples of the ZAC sequence alternate with samples of the circular-shifted sequence. A repeater generates a baseband preamble signal by repeating the sequence received from the second generator.

Abstract: Provided is a method and apparatus for transmitting/receiving data in a frequency overlay communication system. A transmitter generates a data stream for data transmission, and performs Inverse Fast Fourier Transform (IFFT) on the generated data stream according to a predetermined first frequency band before transmission. Upon receiving a particular signal, a receiver performs Fast Fourier Transform (FFT) on the received signal according to a predetermined second frequency band, and restores the received signal.

Abstract: Disclosed are a pilot tone generation apparatus and a pilot tone generation method for improving channel estimation performance in an OFDMA/CDM communication system. In a pilot tone generation method for channel estimation in a broadband wireless access communication system, if given data symbols and a pilot symbol are input, the input data symbols are code-division multiplexed. A pilot symbol value for generating a sub-carrier of a specific position into the pilot tone is produced and spread, correspondingly to a code-division multiplexed result value of the data symbols Also, a spreading value for the pilot symbol value and the resulting code-division multiplexed value of the data symbols are added up, and the pilot tone is generated at a given position on a frequency axis, which position is predetermined through a result of the adding up.

Abstract: Disclosed is an apparatus for transmitting a bit-interleaved coded modulation (BICM) signal in an orthogonal frequency division multiplexing (OFDM) system. A serial-to-parallel (S/P) converter generates bit streams using coded bits according to the number of transmission antennas and a modulation order of a predetermined modulation scheme. An interleaver applies at least one offset to the bit streams and performs interleaving on the offset-applied bit streams. A combiner combines the interleaved bit streams according to the number of transmission antennas.

Abstract: In a mapping method for signal combining in a wireless communication system, it is determined whether a full search is possible for an arbitrary mapping table. If the full search is possible, search metric values are computed for all possible constellation combinations and a constellation with a minimum value is produced using the computed search metric values. If the full search is not possible, a search metric value within an irregular constellation is continuously reduced, the reduced search metric value corresponding to a minimum value is obtained and a constellation with a minimum value is produced using the obtained reduced search metric value.

Abstract: Disclosed is a system and method for modulating a pilot symbol sequence in a multi-carrier communication system. The method including producing a pilot symbol sequence corresponding to a predetermined time interval by removing a data symbol sequence from time domain signal to be transmitted, the time domain signal including the data symbol sequence and the pilot symbol sequence; and modulating the pilot symbol sequence so that a part of the time domain signal corresponding to a predetermined number of pilot symbols in the pilot symbol sequence has a predetermined pattern.

Abstract: An apparatus and method for estimating and correcting an uplink frequency offset in an OFDM communication system are provided. A subscriber station (SS) once repeats an OFDM symbol including a ranging code allocated from a BS and transmits the repeated OFDM symbols to the base station (BS). The BS demodulates the two successive OFDM symbols received from the SS using the ranging code, sums the demodulated signal for each FFT window, and estimates the uplink frequency offset by multiplying the complex conjugate of a sum for a first FFT window by a sum for a second FFT window by the base station. The BS transmits a message including information about the frequency offset estimate to the SS. The SS then corrects the uplink frequency offset using the frequency offset information.

Abstract: An apparatus and method for transmitting/receiving an random access channel (RACH) signal in a broadband wireless communication system where a total uplink frequency band is divided into M sub-bands are provided. In the RACH transmitting apparatus, a generator generates an access code. A sub-carrier allocator divides the access code into M sub-blocks and allocates each of the M sub-blocks to successive sub-carriers in a sub-band. An inverse fast Fourier transform (IFFT) processor generates an orthogonal frequency division multiplexing (OFDM) symbol by performing an IFFT on the allocated sub-blocks.