Abstract: An apparatus and method for UpLink (UL) radio resource allocation in a wideband wireless communication system are provided. In a method of operating a Relay Station (RS) for UpLink (UL) radio resource allocation in a wideband wireless communication system, the method includes relaying to a Base Station (BS) a resource request message of at least one or more Mobile Stations (MSs); receiving data from the at least one or more mobile stations; if the received data is non-real time traffic, queuing the data received from the mobile stations according to a traffic type; and requesting the base station to allocate necessary radio resources by checking a queue status. Accordingly, a delay can be reduced when the UL resource is allocated to an relay station for real time traffic.

Abstract: A signal transmission apparatus in a communication system, includes: a first IFFT unit for generating a first signal by performing inverse fast Fourier transform on a first communication service signal corresponding to a first communication scheme; a first CP inserter for generating a second signal by inserting a first cyclic prefix having a length corresponding to the first communication scheme into the first signal; a second IFFT unit for generating a third signal by performing inverse fast Fourier transform on a second communication service signal corresponding to a second communication scheme; a second cyclic prefix inserter for generating a fourth signal by inserting a second cyclic prefix having a length corresponding to the second communication scheme into the third signal; and a transmission unit for multiplexing the second signal and the fourth signal and transmitting the multiplexed signals.

Abstract: Apparatuses and methods for processing a bandwidth request in a multihop relay Broadband Wireless Access (BWA) communication system are provided. A communication method of a Relay Station (RS) includes determining a number of bandwidth request ranging codes received from Subscriber Stations (SSs); and reporting the number of the bandwidth request ranging codes to a Base Station (BS). A communication method of the BS includes allocating a resource to an RS to report on a number of detected bandwidth request ranging codes; and receiving a report on the number of the bandwidth request ranging codes using the allocated resource.

Abstract: An apparatus and method for correcting a CPE in a signal reception apparatus of a multi-carrier communication system are provided, in which an auto-correlation of a reference signal estimated from a reference symbol among a plurality of symbols is detected, a cross-correlation between a channel estimate of the reference signal and an actual received reference signal is detected, and the CPE of the remaining symbols except the reference symbol is corrected using the auto-correlation and the cross-correlation.

Abstract: Provided is an apparatus and method for determining a data transmission rate in consideration of the queue length of a Relay Station RS in a multi-hop relay system. A Base Station BS apparatus of the multi-hop relay system includes a receiver and a calculator. The receiver receives channel condition information and queue length information for a Mobile Station MS from an RS. The calculator of the BS apparatus determines a data transmission rate between the BS and the RS for data of the MS using the channel condition information and the queue length information.

Abstract: Channel estimation apparatus and method for interference cancellation in a mobile communication system are provided. The channel estimation method includes detecting a preamble from a received signal and estimating a primary channel using the detected preamble; calculating a short-term correlation matrix using the primary channel; and estimating a secondary channel using the calculated short-term correlation matrix according to a certain channel estimation scheme.

Abstract: Apparatus and method for measuring an SINR in a mobile communication system using preambles. Calculated are an average noise power using a CP of an RX signal, a signal power of a serving segment, an average power of the serving segment, and an interference power of the serving segment, an average power of each interference segment, and an interference power of each interference segment using the difference between the calculated average noise power and the calculated average power. An SINR of the RX signal is calculated by dividing the calculated signal power of the serving segment by the sum of the calculated average noise power and the total interference power of all the segments.

Abstract: An apparatus and method for channel estimation in a wireless communication system are provided, in which a first channel estimate is calculated using a pilot signal included in a received signal, a data signal included in the received signal is demodulated using the first channel estimate, a second channel estimate is calculated using the demodulated data signal, the first channel estimate is corrected using the second channel estimate and the data signal is demodulated using the corrected first channel estimate.

Abstract: Provided are an apparatus and a method for acquiring frame synchronization in a broadband wireless communication system using a plurality of preamble sub-carrier patterns. The apparatus includes a plurality of preamble detectors that perform phase compensation on input sample data in accordance with a corresponding pattern and computes correlation values for respective time indices by using the phase-compensated sample data; an adder that sums the correlation values received from the preamble detectors; and a synchronization determination unit that compares sums obtained from the adder so as to select a maximum value and determines a time index corresponding to the maximum value as the frame synchronization.

Abstract: An apparatus and method for allocating a frequency band to an MS in a cellular system with a frequency reuse factor of N are provided, in which a frequency allocator determines whether the MS receives data simultaneously from two BSs using neighboring FAs and allocates a frequency band to the MS according to the determination, and a subcarrier mapper maps the data to subcarriers according to the frequency band allocated to the MS.

Abstract: An apparatus and method for receiving a signal in a communication system are provided. Information related to a first modulation scheme applied to a frequency domain in a serving base station is received from the serving base station. Information related to a second modulation scheme applied to the frequency domain in at least one neighbor base station is received from the at least one neighbor base station. A signal is received in the frequency domain. Channel state information is generated by estimating the received signal. A determination is made as to whether to use interference cancellation using the channel state information, the first modulation scheme information and the second modulation scheme information.

Abstract: A method is provided for transmitting/receiving data in a communication system. The method includes determining, when data to be transmitted to at least one Mobile Station (MS) is generated, a region where an MS that receive the generated data among the at least one MS is located, allocating resources of a data transmission region divided into a first region and a second region to the MS that receive the generated data according to the determination result, including the generated data in a region where the resource is allocated, and including, in a MAP message region, resource allocation information of the region where the data is included and information on an MS that receive the data included in the resource-allocated region, and transmitting, to the MS, a frame including the region in which the generated data is included, and the MAP message region.

Abstract: In a communication system, information regarding a first modulation scheme applied to a frequency domain in a serving base station is received from the serving base station. A signal of the frequency domain is received. A second modulation scheme is set by estimating a modulation scheme applied to the frequency domain in at least one neighbor base station from the received signal. Channel state information is generated by estimating the received signal. An operation for selecting whether to use interference cancellation is performed using the channel state information, the first modulation scheme information and the second modulation scheme.

Abstract: A symbol demapping method and apparatus for efficient interference cancellation in a wireless communication system. Decision signal points are generated which include decision signal points based on a modulation scheme and a virtual signal point added to a zero point. A magnitude of a complex value of an input signal is compared with a threshold based on system setting. When the magnitude of the complex value is less than the threshold, the virtual signal point of the zero point is mapped and output as a target decision signal point. When the magnitude of the complex value is greater than or equal to the threshold, one of the decision signal points based on the modulation scheme is mapped and output according to the com0plex value.

Abstract: A method for allocating resource in a communication system. The resource allocation method includes dividing a data transmission region into a first region and a second region; allocating resource of the first region when a first Mobile Station (MS) among MSs is an MS located in a non-interference region; and allocating resource of the second region when a second MS among the MSs is an MS located in an interference region.

Abstract: Provided are an ARQ apparatus and method for a multihop system in a broadband wireless access communication system. The ARQ method of a relay includes determining if the relay successfully receives specific data from a source and transmitting the specific data to a destination; receiving feedback data from the destination and determining if the destination successfully receives the specific data; generating feedback data including data indicating if the relay and the destination successfully receive the specific data, and outputting the feedback data to the source; and retransmitting the specific data, when the relay successfully receives the specific data but the destination fails to receive the specific data. Accordingly, when the MH-BTS successfully receives the data from the source but the destination fails to receive the data, the source does not retransmit same data to the MH-BTS.

Abstract: A handover apparatus and method for a multi-hop system in a BWA communication network are provided. In a handover system supporting multi-hop system in a BWA communication network, a BS periodically broadcasts a message with neighboring BS/RS information. When a new BS or RS needs to be added, an RS periodically broadcasts the broadcast message received from the BS with information about the new BS or RS. An MS receives the broadcast message from the RS and requests information about BSs or RSs to which the MS can perform a handover by notifying candidate BSs or RSs for the handover. The candidate BSs or RSs may include a BS or RS not included in the broadcast message, if the MS detects the BS or RS by scanning. The MS selects a target BS or RS based on the BS or RS information received from the BS, and performs the handover to the target BS or RS.

Abstract: Provided is a multi-hop wireless mobile communication system where a plurality of nodes exist. To select a serving node to be provided with a service, a Mobile Station (MS) receives relay information provided for serving node selection from at least two nodes and selects a first mode of selecting a node that requires the minimum time for unit data transmission/reception as the serving node or a second mode of selecting a node that can transmit and receive the maximum data per unit time as the serving node, based on the received relay information, in order to select the serving node.

Abstract: A method is provided for transmitting and receiving data in a multi-hop wireless mobile communication system having a first mobile station (MS), a second MS, a base transceiver station (BTS), and a relay BTS. The method includes allowing the first MS to directly communicate with the BTS, and allowing the second MS to communicate with the BTS by relay of the relay BTS; performing communication between the BTS and the first MS and communication between the relay BTS and the second MS using a first frame; and performing communication between the BTS and the relay BTS using a second frame.

Abstract: Apparatus and method for simultaneously selecting two cells in a broadband cellular communication system with a frequency reuse factor of N. Adjacent cells are searched and the RX power strengths of the adjacent cells are measured. Cells with RX power strengths greater than a predetermined value are selected among the adjacent cells. Two cells are selected among the selected cells and the FAs and RX power strengths of the two cells are compared. If the two cells have adjacent FAs and/or similar RX power strengths, the two cell are selected to perform communication. The apparatus and method simultaneously receives data signals from two cells with adjacent FAs in a cellular environment with a frequency reuse factor of N, by sharing the adjacent FAs.