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.

Abstract: Disclosed is a method for transmitting a signal in a communication system supporting multiple communication service modes. The base station includes at least one preamble generator for generating a preamble to which a sequence and a cell IDentifier (ID) of the base station are allocated, the sequence being one-to-one mapped to one communication service mode supportable by the base station. By the method, in mobile communication systems after the 3G communication system, it is possible to support multiple communication service modes optimized for multiple communication environments in a single communication system and to provide each mobile station with an optimum communication service mode for a specific communication environment of the mobile station.

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: Provided is a parallel interleaving method and apparatus. The parallel interleaving method includes dividing input information bits into a predetermined number of sub-blocks and interleaving the information bits divided into the sub-blocks according to a predetermined first interleaving rule.

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: 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 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: Provided is a transmitter apparatus in a MIMO wireless communication system. The transmitter apparatus includes a controller and a space-time encoder. The controller generates a space-time encoding code according to a multiplexing order, the number of transmitter antennas, and the number of receiver antennas. The space-time encoder space-time-encodes a TX signal using the generated space-time-encoding code.

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: An apparatus and method for allocating frequency resources in an OFDMA mobile communication system. A hop group includes a plurality of hop units, each hop unit being minimum frequency resources which can be allocated in a two dimensional time-frequency domain and a total frequency band of the OFDMA mobile communication system is divided into subbands. A base station allocates at least one hop unit to each mobile station, permutes the sequence of hop units included in each hop group according to a first permutation sequence, allocates the hop units of the each hop group to subbands, permutes the sequence of hop units included in each of the subbands according to a second permutation sequence, and determines the positions of the hop units permuted according to the second permutation sequence to be the positions of physical subcarriers allocated to the each mobile station.

Abstract: An apparatus and method for operating a radio access network in a broadband mobile communication system are provided. A 1-tier node includes a first communicator for exchanging a plurality of pieces of control information for establishing a call of a Mobile Station (MS) with a higher-tier node, and a controller for allowing data of the MS to be transmitted and received through a radio access network having a 1-tier structure according to call establishment information received from the higher-tier node.

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: 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: 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 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 method of determining useable combinations of variables for transmitting a subpacket of an encoder packet in a communication system is disclosed. First, an arbitrary combination from a plurality of all combinations of transmission variables is selected based on a number of currently useable Walsh codes and channel environment. Next, an arbitrary MPR is determined based on a number of useable encoder packet bits, a number of useable slots, and the number of currently useable Walsh codes, all of which belong to the selected arbitrary combination transmission variables. Thereafter, a final MPR, which is the smallest one of MPR values of a MPR set that corresponds to the number of useable encoder packet bits and the number of useable slots, is determined, and a final number of Walsh codes is calculated based on the number of useable encoder packet bits, the number of useable slots, and the determined final MPR.

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 method for removing interference in a transmitting end of a multi-antenna system is provided. The method includes decomposing a channel matrix comprising 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: An apparatus and method for feeding back Channel Quality Information (CQI) in a wireless communication system are provided. Total channels are grouped into certain number of groups according to downlink channel estimates. Group indexes are determined for the channels. Feedback information is generated using the group indexes of the channels and representative values of the groups. Then, the generated feedback information can be transmitted.

Abstract: An apparatus and method for implementing SDMA in a multi-user multi-antenna system are provided, in which SDMA users are selected from among total users according to channel state information of the total users, and the number of transmission streams to be allocated to each of the SDMA users is determined by a tree search method.