Abstract: An apparatus and method for setting a guard band with respect to an asynchronous Base Station (BS) in a broadband wireless communication system are provided. The BS includes a controller for generating a control signal to set a guard band when a time offset occurs between BSs; a mapper for mapping and outputting transmit data to a band, excluding the guard band, of a unique band of the BS according to the control signal; and an operator for multicarrier-modulating data fed from the mapper.

Abstract: An Apparatus and a method for interference cancellation in a wireless communication system are provided. When a resource of an Interference Cancellation (IC) zone is allocated to a terminal traveling in a service coverage, resource allocation information relating to an IC zone of neighbor cells is gathered. Resource allocation information is generated relating to the resource allocated to the terminal comprising resource allocation information of the IC zone of the neighbor cells. The resource allocation information relating to the resource allocated to the terminal is transmitted to the terminal. Accordingly, when the interference is present, the interference cancellation is carried out to reduce the load on the terminal and enhance the reception performance.

Abstract: A method for transmitting and receiving data in a communication system. The method generates a frame for mapping each of multiple communication service modes of a base station providing the multiple communication service modes to a user terminal, in units of subframes each having a time interval and a frequency band. The method includes estimating a communication service mode supporting an optimal service among the multiple communication service modes provided by the base station supporting the multiple communication service modes, and sending to the base station a random access message for access to the base station over a shared channel.

Abstract: Method and apparatus for controlling data transmission rate in a wireless communication system during handoff comprises a terminal recognizing an active set comprising a serving base station and at least one non-serving base station with respect to the terminal communicating with the network at a first data transmission rate, receiving a first rate control parameter from the serving base station and a second rate control parameter from the at least one non-serving base station, wherein the first and second rate control parameters are associated with determination of a second data transmission rate of the terminal during the handoff and determining the second data transmission rate in response to the first and the second rate control parameters, wherein the second data transmission rate is one of increased rate, decreased rate and same rate from the first data transmission rate.

Abstract: A method for providing a service in a communication system is provided. A Base Station (BS) supporting a plurality of communication service modes allocates communication resources for each of the plurality of communication service modes according to a ratio determined in accordance with a communication service mode preferred by a terminal. The BS transmits a combination of resources allocated for each of the plurality of communication service modes to the terminal. The communication service mode preferred by the terminal is determined using at least one of channel condition of the terminal, moving velocity, preferred communication mode, required performance, billing system, and user preference.

Abstract: An apparatus and method for renewal-based resource allocation in a Broadband Wireless Access (BWA) system are provided. A Base Station (BS) allocates resources to a Mobile Station (MS) by resource allocation information. It is determined whether the MS requires continuous resource allocation or whether the MS does not have transmission data temporarily, when a resource allocation duration for downlink resources allocated to the MS has expired. One of resource allocation termination, resource allocation renewal, and temporary resource lending to another MS is performed according to the determination. Information for updating the resource allocation information is transmitted to the MS.

Abstract: Provided are a system and a method for transmitting/receiving data in a communication system. The method includes calculating a processing matrix of a transmission unit for transmitting data, a processing matrix of a reception unit for receiving the data, a channel matrix formed by a plurality of transmission antennas and a plurality of reception antennas, and a parameter of the transmission data, when the data to be transmitted to the plurality of reception antennas via the plurality of transmission antennas is generated; determining a minimum value of a Minimum Mean Square Error (MMSE) according to the calculated matrixes and parameter; and transmitting/receiving the data using an MMSE multiplexing scheme based on the determined minimum MMSE value.

Abstract: A method and system for transmitting and receiving resource allocation information in a communication system are disclosed, in which an Relay Station (RS) receives a resource allocation information message from a Base Station (BS), detects a first resource allocation information from the resource allocation information message, and detects a second resource allocation information intended only for the RS using the first resource allocation information.

Abstract: A method and system for selecting an RS in an MS in a communication system are provided, in which the MS measures channel qualities between the MS and at least two RSs, and selects an RS for relaying signals between the MS and a BS from among the at least two RSs according to the channel quality measurements.

Abstract: Apparatus and method for allocating a Channel Quality Information CHannel (CQICH) in a wireless communication system are provided. The method includes determining CQICH patterns required for users using information of one or more users to which CQICH resources are to be allocated, and selecting a CQICH pattern block, including all of the determined CQICH patterns, from among a plurality of pre-generated CQICH pattern blocks; and allocating CQICH sub-blocks corresponding to the users' required CQICH patterns using resource layout information of the CQICH sub-blocks corresponding to the CQICH patterns of the selected CQICH pattern block, and transmitting CQICH allocation information to a Mobile Station (MS).

Abstract: Apparatus and method for controlling data transmission rate in a wireless communication system during handoff comprises a terminal recognizing an active set comprising a serving base station and at least one non-serving base station with respect to the terminal communicating with the network at a first data transmission rate, receiving a first rate control parameter from the serving base station and a second rate control parameter from the at least one non-serving base station, wherein the first and second rate control parameters are associated with determination of a second data transmission rate of the terminal during the handoff and determining the second data transmission rate in response to the first and the second rate control parameters, wherein the second data transmission rate is one of increased rate, decreased rate and same rate from the first data transmission rate.

Abstract: Provided is an apparatus and method for resource allocation for multicast data in a broadband wireless access system. In the method, multicast packets are scheduled. Thereafter, a resource allocation message for the scheduled multicast packets divided into a second multicast resource allocation message including information of a user group using a multicast ID and a first multicast resource allocation message including information transmitted in common to users of the user group, and the corresponding message including changed information is transmitted for a change of information. Therefore, it is possible to reduce a waste of resource that is due to the duplicate transmission of some fields of resource allocation information about multicast data.

Abstract: Disclosed is a space-time coding apparatus and method to flexibly adjust diversity/multiplexing orders in a multiple-antenna system. The transmitting apparatus for the multiple-antenna system includes a space-time code controller, an encoder, a demultiplexer, and a space-time encoder. The space-time code controller generates space-time codes by determining bases according to a multiplexing order required by a receiver. The encoder modulates and encodes data destined for the receiver in accordance with a predetermined modulation level. The demultiplexer demultiplexes data received from the encoder in order to transmit the data through at least one antenna. The space-time encoder space-time-codes the demultiplexed data using the space-time codes.

Abstract: Provided are a relaying method and system in a communication system having a BS, a MS for communicating with the BS, and an RS for relaying signals between the BS and the MS, in which the RS receives a first pilot sequence from the BS, replaces the first pilot sequence with a second pilot sequence, and transmits the second pilot sequence to the MS. Here, a partial cross correlation between the first and second pilot sequences is always ‘0’.

Abstract: An apparatus and method for removing interference in a transmitting end of a multi-antenna system is provided. The method includes decomposing a channel matrix including channel coefficients for a plurality of terminals, calculating a value proportional to an interference signal for each of antennas, and calculating a sum of a transmission signal and the calculated value for each terminal and multiplying the calculated sum by the decomposed channel matrix. Accordingly, channel capacity can be improved by optimizing a data transfer rate and transmission power for each terminal.

Abstract: Provided are a spatial multiplexing apparatus and method in a Multiple Input Multiple Output (MIMO) system. The spatial multiplexing detection method includes estimating channels of a received signal, and sorting the estimated channels in descending order according to a scheme; generating a subsystem of a minimum unit by nulling an arbitrary channel among the sorted channels; performing a modified maximum likelihood (MML) in the subsystem of the minimum unit to calculate a number of transmission signal vectors; and calculating Euclidean distances of the number of the transmission signal vectors, and selecting a transmission signal vector having a minimum Euclidean distance. Accordingly, the receiver exhibits a performance level similar to a Maximum Likelihood (ML) and can obtain the complexity similar to successive interference cancellation (SIC).

Abstract: An apparatus and method for scheduling a multiuser and a single user in a Multiple Input Multiple Output (MIMO) system are provided. The method for scheduling a multiuser and a single user at BS in MIMO system includes determining ratios of MultiUser-MIMO (MU-MIMO) chunks and Single User-MIMO (SU-MIMO) chunks to allocation chunks, determining the MU-MIMO chunks in the determined ratio and the remaining chunks as the SU-MIMO chunks, transmitting chunk information relating to the determined chunks to one or more Mobile Stations (MSs), and, when Channel Quality Information (CQI) feedback information relating to the determined MU-MIMO chunks and the determined SU-MIMO chunks is received from the MSs, allocating chunks and streams for MU-MIMO/SU-MIMO to users who maximize overall capacity using the CQI feedback information.

Abstract: A transmission method based on a Hybrid Automatic Repeat Request (HARQ) scheme for in a communication system. A codeword is generated using a Low Density Parity Check (LDPC) code. Parity bits of the codeword are classified on a basis of a transmission priority. Parity bits with an identical transmission priority are grouped. An information bit group of the codeword and parity bit groups with the identical transmission priority are shuffled in a predefined pattern. A packet is generated from the shuffled information bit group and the shuffled parity bit groups based on the transmission priority. The generated packet is retransmitted in response to a retransmission request. The transmission method can obtain the effect of channel interleaving by setting a transmission priority according to importance of puncturing target blocks, shuffling blocks with the same priority, and shuffling and transmitting bits configuring each block.

Abstract: A method for performing ranging by a mobile station in a communication system. The method includes transmitting a ranging sequence to a relay station; receiving an added signal of a reference sequence of the relay station and the ranging sequence, from the relay station; performing a correlation operation on each of the ranging sequence and the reference sequence in the added signal; estimating a time difference between the ranging sequence and the reference sequence depending on the correlation operation; and transmitting the signal to the relay station taking the time difference into account.

Abstract: The present invention relates to Walsh Code Allocation (WCA) field in the Packet Data Control Channel. One of the embodiments of the WCA field is use of the WCA field as Last Walsh Code Index (LWCI) field in the message format of the PDCCH. The LWCI field indicates the corresponding last code index or the corresponding number of Walsh codes in a Walsh Code Index (WCI) Table/List/Set. In alternative embodiments, the WCA indicates a general set of Walsh codes or a specific set of Walsh codes in the WCI table. The WCA fields may or may not be used with one of power ranking and sequential decoding, but is preferable used. The WCA field has various advantages including but not limited to efficient use of system resources.