Abstract: A signal reception apparatus for a communication system is disclosed in which the signal reception apparatus receives a signal and decodes the received signal using a second decoding scheme approximated from a first decoding scheme. The second decoding scheme is a scheme of applying a correction value to a third decoding scheme approximated from the first decoding scheme, and the correction value is a value for correcting a difference between a first signal obtained by decoding the received signal using the first decoding scheme and a second signal obtained by decoding the received signal using the third decoding scheme.

Abstract: An apparatus and method of encoding a block Low Density Parity Check (LDPC) code in a signal transmission apparatus is disclosed. The method includes generating a block LDPC codeword by encoding an information vector using a second parity check matrix when a code rate to be used in the signal transmission apparatus is a second code rate less than a code rate of a first parity check matrix as a first code rate.

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: A method of performing a handover between a first device and a second device is provided. The method including: transmitting a handover request frame for requesting a handover, including information about a reason for requesting the handover, to the second device; receiving a handover response frame including handover request result information indicating whether the handover request is accepted, from the second device; and selectively performing the handover with the second device based on the handover response frame.

Abstract: A method and apparatus of transmitting video content compressed by a codec to a second device is provided. The method includes: transmitting a codec selection request frame to the second device, the codec selection request frame includes an identifier of at least one codec to be used to compress the video content and requests approval of the use of the at least one codec; receiving a codec selection response frame from the second device, the codec selection response frame includes approval information indicating whether the use of the at least one codec is approved; and transmitting video content compressed by the at least one codec to the second device based on the codec selection response frame.

Abstract: A method of performing hand-over in a personal basic service set (PBSS) including a plurality of stations and one coordinator is provided. An association request frame comprising PCP capability information, and requesting to associate to the PBSS, is received from each of the stations. The PCP capability information comprises information regarding at least one of whether each of the stations supports a power source capability of continuous power supply, whether each of the stations supports a channel time allocation function, and whether each of the stations supports a network clustering function. An association response frame, indicating whether the association request received from each of the stations is approved, is transmitted to each of the stations, and a priority to be a coordinator of the stations is determined based on the PCP capability information. Hand-over is performed with one of the stations according to the determined priority.

Abstract: An apparatus and method for performing Automatic Retransmission reQuest (ARQ) of a Relay Station (RS) in a wireless communication system using a relay scheme are provided. The method includes receiving data from a transmitter and transmitting the received data to one or more receivers; and receiving Acknowledgment (ACK)/Negative-Acknowledgment (NACK) information for the data received from the one or more receivers and transmitting the received ACK/NACK information to a Base Station (BS).

Abstract: Provided is an apparatus and method for low-complexity scheduling in a multi-user Multi-Input Multi-Output (MIMO) system. In a method for scheduling in a MIMO system, a vector is set on the basis of channel information for all user terminals. A scalar for the vector is initialized. A user terminal that has the greatest scalar among unselected user terminals is selected. A user set is updated by adding the selected user terminal therein. The vector and the scalar for a user terminal not included in the user set are updated. Accordingly, a high transmission capacity can be provided while minimizing the influence of an interference signal. Also, the computation amount can be reduced greatly.

Abstract: An apparatus and method for reducing MAP channel overhead in a broadband wireless communication system. In a Base Station (BS), a traffic classifier classifies transmission data into a first group and a second group according to user channel information and packet sizes of the transmission data. A MAP channel configure configures a MAP channel to include information about users of the first group and positions of data for the users, information indicating whether users of the second group have succeeded in random access in a second uplink data region of a previous frame, and information about resource reservation for a current frame for the second group. A channel mapper maps the first group to a first downlink data region and maps the second group to a second downlink data region according to the MAP channel.

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: A method and apparatus for transmitting compressed video content are provided. The method includes transmitting a codec selection request frame, the codec selection request frame including an identifier of one or more codecs to be used to compress video content and requesting approval of the use of the codec, receiving a codec selection response frame, the codec selection response frame including result information indicating whether the use of the codec is approved, and transmitting video content frames for the video content compressed by the approved codec based on the codec selection response frame. Each video content frame includes frame type information indicating a type of compression applied to the video content included in the video content frame.

Abstract: An apparatus and a method for transmitting broadcasting signals in a broadcasting system having multi-antenna are provided. The apparatus comprises at least one antenna, a signal generator for generating two or more broadcasting signals to be transmitted, at least two of the two or more broadcasting signals being generated according to different user-required quality characteristics, a multi-antenna modulator for modulating each of the broadcasting signals according to one of a plurality of multi-antenna transmission methods selected for each of the broadcasting signals according to the user-required quality characteristics of the respective broadcasting signals, and a transmitter for transmitting the modulated signals via the at least one antenna.

Abstract: An apparatus and method for signal detection in a Broadband Wireless Access (BWA) system are provided, in which in a transmitter, a first preamble sequence generator generates preamble sequences, a low-Peak-to-Average Power Ratio (PAPR) preamble sequence selector selects a first low-PAPR preamble sequence from among the generated preamble sequences, a preamble sequence copier copies the first low-PAPR preamble sequence at least once and outputs the first low-PAPR preamble sequence and the at least one copy, a complex conjugator generates preamble sequences orthogonal to the first low-PAPR preamble sequence and the at least one copy by calculating complex conjugates of the first low-PAPR preamble sequence and the at least one copy, and a second preamble sequence generator generates at least one second low-PAPR preamble sequence using the first low-PAPR preamble 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 a method for selecting one of a plurality of relay modes in a wireless communication system are provided. The method includes checking a channel state between a Mobile Station (MS) and each of at least one Relay Station (RS), selecting the relay mode for supporting a relay service using the determined channel state between the MA and each of the at least one RS, and providing the relay service to the MS using the selected relay mode. Thus, system throughput and outage performance can be enhanced by using the appropriate relay mode based on the MS distribution or the channel condition.

Abstract: Provided is an apparatus and method for estimating an uplink frequency offset in a wireless communication system. In a receiving apparatus of a wireless communication system using a random access channel composed of two equivalent sequences, the apparatus includes a channel receiver which extracts samples corresponding to the two sequences from an input random access channel signal; a correlator which computes first and second correlation values by correlating preceding and trailing samples among the samples output from the channel receiver with a predetermined sequence; and a frequency offset estimator which estimates a frequency offset by using a ratio of the second correlation value to the first correlation value output from the correlator.

Abstract: A method and apparatus for changing a frequency band used for communication between first and second devices supporting multiple frequency bands. The method includes transmitting a frequency band change request frame including information regarding a communication capability of the first device and a frequency band change request for requesting to change a frequency band currently being used for communication between the first and second devices, to the second device; receiving a frequency band change response frame corresponding to the frequency band change request frame, from the second device; and selectively changing the frequency band currently being used to another frequency band based on the received frequency band change response frame.

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: An apparatus and method of receiving a signal in a communication system are provided, in which a signal is received and decoded by a PPS scheme being an LDPC decoding scheme in which an order of performing a node operation is scheduled.

Abstract: An apparatus and method for transmission and reception in a multi-user Multiple-Input Multiple-Output (MIMO) communication system are provided. In a transmitter, a filter portion receives quantized Channel State Information (CSI) and Channel Quality Information (CQI) from a receiver, calculates a transmit filter value using on the quantized CSI and the CQI, determines an appropriate AMC level for the receiver, and sends a pilot signal including the transmit filter value and information about the determined AMC level on subcarriers in one of a preamble and data symbols. An antenna is used to send the output of the filter portion and receives data from the receiver.