Abstract: An apparatus and method for canceling ISI in a broadband wireless communication system are provided. In a transmitter of the broadband wireless communication system, a controller acquires a CP length, a puncturing pattern, and a time sample interval according to a delay spread. A puncturer punctures coded data in the puncturing pattern. An IFFT processor IFFT-processes the punctured coded data and outputs sample data. A CP inserter generates an OFDM symbol by inserting a copy of a last part of the sample data before the sample data. Here, the length of the last part of the sample data is equal to the CP length. A D/A converter converts the OFDM symbol to an analog signal at a sampling rate determined by the time sample interval.

Abstract: A method of signal transmission/reception by a transmitter in a wireless mobile communication system is provided.

Abstract: Disclosed is a method for transmitting a pilot symbol from base stations (BSs) to a subscriber station (SS) in a communication system which includes the base stations located adjacent to each other, the method includes the steps of transmitting BS-identifying sub-carriers which represent sequences for identifying the base stations in a frequency domain of the pilot symbol; and transmitting PAPR (Peak to Average Power Ratio) sub-carriers which represent sequences for reducing a PAPR of the pilot symbol together with the transmission of the BS-identifying sub-carriers in the frequency domain.

Abstract: Disclosed is an apparatus and method for allocating downlink/uplink subchannels for a soft handover in a broadband wireless access communication system, wherein the method includes the steps of configuring FUSC subchannels based on a predetermined FUSC subchannel configuration scheme by using an equal seed value in all cells; allocating a predetermined number of FUSC subchannels of the configured FUSC subchannels as soft handover subchannels; and allocating remaining subchannels, except for the FUSC subchannels allocated as the first subchannels, as non-soft handover subchannels based on the FUSC subchannel configuration scheme by using a specific seed value.

Abstract: A method for forming a subchannel in a communication system where a first communication system and a second communication system coexist. The method includes determining a first tile set by arranging first tiles remaining after forming at least one first subchannel for the first communication system among frequency resources, including a plurality of tiles, available for the first communication system; determining a second tile set by inserting second tiles which are independent of the frequency resources and are available for the second communication system into the determined first tile set at predetermined positions; forming at least one second subchannel for the second communication system by selecting a predetermined number of tiles from the second tile set; and performing communication using at least one of the first subchannel and the second subchannel.

Abstract: An apparatus and method for transmitting and receiving a signal according to a change of downlink channel information by a mobile station in a broadband wireless access communication system. The method includes: detecting the change of the downlink channel information; receiving a report from a base station that there is data for the mobile station; and reporting the change of the downlink channel information to the base station, so that the base station and the mobile station have same downlink channel information.

Abstract: A method for generating a non-binary Low Density Parity Check (LDPC) code. The method includes generating non-binary identity matrixes so as to satisfy at least one condition, wherein the non-binary LDPC code is defined by a parity check matrix, and the parity check matrix includes a plurality of sub-matrixes, which are divided into zero matrixes and the non-binary identity matrixes.

Abstract: Disclosed is a method of transmitting common control information by a base station in a communication system including a first communication system and a second communication system different from each other. In the communication system, a frame for carrying the common control information includes an uplink sub-frame and a downlink sub-frame, each of which includes a resource allocation area for the first communication system and a resource allocation area for the second communication system. The method includes: configuring the common control information to be received by a mobile station belonging to the second communication system; and transmitting the common control information through the resource allocation area for the second communication system included in one of the uplink sub-frame and the downlink sub-frame.

Abstract: A frequency reuse apparatus and method for a Mobile Station (MS) using a multiple-antenna in a broadband wireless access communication system are provided. The method includes dividing a first frequency band into ‘N’ second frequency bands where ‘N’ equals a number of Base Stations (BSs); dividing each second frequency band into ‘n’ third frequency bands; allocating each of the ‘N’ second frequency bands according to the number of receive antennas; and allocating the third frequency bands to all of the BSs, respectively.

Abstract: A method to transmit a packet of a BS in a communication system using a HARQ scheme is provided. The method includes assigning resource for transmitting a packet to a mobile station, and transmitting a first packet to the mobile station using the assigned resource; transmitting timing information on which a second packet is transmitted to the mobile station when the BS does not receive information indicating that the mobile station decoded the first packet successfully or when the BS receives information indicating that the mobile station failed to decode the first packet; and transmitting the second packet to the mobile station on a timing point corresponding to the timing information.

Abstract: An apparatus and method for maintaining backward compatibility with a narrow-band wireless communication system in a wide-band wireless communication system is provided. The base station comprises a scheduler, a control information generator, a resource mapping unit and a transmitter. The terminal comprises a resource allocation information checking unit, a receiver and a transmitter.

Abstract: An apparatus and method for generating an RS SCH in a wireless communication system are provided, in which a base station checks a BS SCH sequence and a mask sequence, and generates an RS SCH sequence by XOR-operating the BS SCH sequence and the mask sequence.

Abstract: Disclosed is an apparatus and method for transmitting/receiving a signal in a communication system, in which an MCS level or a modulation scheme to be used to an information vector to be transmitted is determined when the information vector is generated, and a codeword vector is generated by encoding the information vector in an encoding scheme corresponding to the determined MCS level or modulation scheme. Thus, a signal can be transmitted in such a manner as to have optimal performance for each MCS level or modulation scheme.

Abstract: An apparatus and method for encoding/decoding a non-binary low density parity check (LDPC) code in a communication system. The apparatus and method includes receiving an information vector; generating a non-binary LDPC code by encoding the information vector into a non-binary LDPC code according to a non-binary LDPC encoding scheme.

Abstract: Disclosed is an apparatus for receiving a signal in a communication system, which receives the signal, and decodes the received signal in a non-binary Low Density Parity Check (LDPC) decoding scheme, in which elements of a Galois field are expressed by an exponent representation, thereby minimizing the memory capacity required for a check node operation when the non-binary LDPC code is decoded.

Abstract: Provided are an apparatus and a method for receiving a signal in a communication system, which receives the signal, and decodes the received signal in a Low Density Parity Check (LDPC) decoding scheme in which the sequence of check node operations is scheduled, thereby improving the decoding performance of the LDPC code.

Abstract: Disclosed is an apparatus and a method for transmitting/receiving a signal in a communication system, which generates an Affine Permutation Matrix-Low Density Parity Check (APM-LDPC) codeword by encoding an information vector in an APM-LDPC encoding scheme which is a preset structured LDPC encoding scheme, and detects the information vector by decoding the signal in a decoding scheme corresponding to the APM-LDPC encoding scheme, thereby making it possible to generate a Low Density Parity Check (LDPC) code in the form of maximizing a girth while minimizing complexity.

Abstract: Provided are an apparatus and method for transmtting/receiving signal, supporting a variable coding rate, in a communication system. The method includes receiving an information vector, generating a child parity check matrix based on a parent parity check matrix according to a coding rate to be applied for generating a block Low Density Parity Check (LDPC) codeword using the information vector, and encoding the information vector into the block LDPC codeword according to the child parity check matrix.

Abstract: A method and apparatus is provided for receiving data in a receiver of a communication system. In the receiver, a first calculator calculates a Log Likelihood Ratio (LLR) value of data transmitted from a transmitter, a decoder performs iterative decoding on the transmitted data using the LLR value calculated by the first calculator. A second calculator determines whether there is an error in the decoded data by calculating an error of the data decoded by the decoder. A storage stores an LLR value of the decoded data according to the determination result of the second calculator. An adder adds up the LLR value calculated by the first calculator and the LLR value stored in the storage.

Abstract: Disclosed is a device and method for coding a block low density parity check (LDPC) code having a variable length. The a device and method include receiving an information word; and coding the information word into a block LDPC code according to a first parity check matrix or a second parity check matrix depending on a length to be applied when generating the information word into the block LDPC code.