Abstract: An apparatus and method for communicating channel information in a relay wireless communication system are provided. A Base Station (BS) apparatus includes a message generator for generating a channel measurement request message to be transmitted to a Relay Station (RS) when the RS is connected; a Transmit (TX) modem for performing a physical layer processing on a message generated by the message generator and for transmitting the processed message; a message analyzer for analyzing a channel measurement response message received from the RS and for obtaining channel estimation information; and a scheduler for performing data scheduling by using the channel estimation information for a predetermined duration corresponding to a plurality of frames.

Abstract: An apparatus and method for providing a relay service in an OFDM mobile communication system are provided, in which symbol synchronization is acquired from a received OFDM signal, an OFDM signal is acquired using the symbol synchronization, and a relay signal is reconfigured by removing a cyclic prefix from the acquired OFDM signal, amplifying the relay signal, and transmitting the relay signal.

Abstract: In a mobile communication system, a relay station (RS) is used for signal exchange with a base station (BS), and includes a first antenna set including at least one antenna, used for signal exchange with the BS, and a second antenna set including at least one antenna, used for signal exchange with a mobile station (MS). The RS selects at least one antenna from the second antenna set for each of the at least one MS, and exchanges a signal with the MS using the selected at least one antenna.

Abstract: Provided is an apparatus and method for providing a synchronous relay service in a multi-hop relay BWA communication system. In the method, a BS-MS link subframe and an RS-MS link subframe are configured for a first section of a subframe in an ith frame. At least one of a BS-RS link subframe, an RS-RS link subframe and an RS-MS link subframe is configured for a second section of a subframe in the ith frame. The BS-MS link subframe and the RS-MS link subframe are configured for a first section of a subframe in an (i+1)th frame. At least one of the BS-RS link subframe, the RS-RS link subframe and the RS-MS link subframe is configured for a second section of a subframe in the (i+1)th frame.

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: 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: Apparatus and method for performing Automatic Retransmission reQuest (ARQ) in a wireless relay communication system are provided, which include performing ARQ with the base station (BS), transmitting data successfully received from the BS to mobile station (MS), and retransmitting corresponding data to the MS when a retransmission indication message is received from the BS. Since the relay station (RS) relays only the errorless data to the receiver, the reliability of the data received at the receiver can be enhanced. The load on the RS can be reduced because the transmitter controls the ARQ.

Abstract: An apparatus and method is disclosed for frequency reuse to avoid interference between a Relay Station (RS) and a Mobile Station (MS) in a multi-hop relay system. The method includes measuring a preamble signal strength of a serving RS, measuring a preamble signal strength of a neighboring RS, and computing a preamble signal strength ratio using the preamble signal strength of the serving RS and the preamble signal strength of the neighboring RS.

Abstract: An apparatus and method for retransmitting data using an RS in a multi-hop network are provided. When retransmitting data in a BS, the BS transmits data and activates a timer therefor. The BS monitors receipt of a response message for the data until the timer expires. The BS receives the response message and, if it is a Non-Acknowledgement (NACK), determines whether an RS has successfully received the data with a BSN associated with the NACK. If the RS has not successfully received the data, the BS retransmits the data. If the RS has successfully received the data, the BS determines a retransmission entity. If the retransmission entity is the RS, the BS transmits a control message commanding retransmission to the RS, and if the retransmission entity is the BS, the BS retransmits the data.

Abstract: Provided is an apparatus and method for efficiently transmitting packets to MSs in a BWA system using RSs. A BS uses an ESH to combines packets, which are to be transmitted through RSs to MSs, into a larger packet prior to transmission. Alternatively, the BS transmits packets, which are to be transmitted to MSs, to an RS without discrimination therebetween, and the RS determines whether the packets are to be transmitted to the MSs, prior to transmission.

Abstract: A method is provided for transmitting/receiving data in a communication system. The method includes measuring, by a Mobile Station (MS), states of channels which are allocated in a scheme prearranged with a Base Station (BS), and encoding measured channel state information in a scheme corresponding to an allocation scheme of the allocated channels; and configuring a message including the encoded channel state information, and transmitting the configured message to the BS.

Abstract: An apparatus and method for configuring a subframe to support a relay service in a multi-hop relay BWA communication system are provided, in which a first zone of a subframe is configured for at least one of communication between a BS and a first MS within the coverage area of the BS and communication between at least one RS and a second MS within the coverage area of the at least one RS, and a second zone of the subframe is configured for at least one of communication between the BS and the at least one RS and communication between the at least one RS and another RS.

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 a method for estimating the channel state of each link in a wireless relay network having fixed RSs are provided. A source estimates a channel of a source-RS link and a channel of a source-destination link using pilot signals received from an Relay Station (RS) and a destination and the source monitors reception of a pilot signal including channel state information of an RS-destination link from the RS. Upon receipt of the pilot signal, the source estimates a channel of the RS-destination link using the pilot signal and the channel state information of the RS-destination link.

Abstract: Provided are an apparatus and a method for providing a concurrent data service to an Mobile Station (MS) through a plurality of heterogeneous networks. In a method for providing a data service to an MS through different wireless networks, the MS measures channel qualities of at least one accessible wireless network and reports the measured channel qualities to an Internet Protocol (IP) packet controller. The IP packet controller selects wireless networks for data transmission on the basis of the reported channel qualities, distributes data destined for the MS, and transmits the distributed data to the selected wireless networks. The selected wireless networks receive the data from the IP packet controller and transmits the received data to the MS. The MS combines and interprets the data received from the selected wireless networks. Accordingly, it is possible to provide a seamless data service to the MS in service environments with a mixture of different wireless communication systems.

Abstract: A method and an apparatus for controlling call admission in an OFDM mobile communication system are provided. Upon receipt of a call admission request, it is determined whether a requested call is a handoff call or a new call and the traffic service type and QoS level of the requested call are determined. The amount of resources required for the call is calculated using the QoS level and the amount of resources of on-going calls is calculated according to the traffic service type. The amount of available resources in a cell is calculated using the amount of resources of the on-going calls and it is determined whether to admit the call by comparing the available resource amount with the required resource amount.

Abstract: An apparatus and method for controlling power in a multi-hop relay broadband wireless communication system are provided. A BS sends a signal to an RS and an MS to estimate distances between the BS, the RS and the MS. Upon receipt of signals from the RS and the MS, the BS measures ToAs of the received signals and detects time information included in the received signals, and calculates propagation delays between the BS, the RS and the MS based on the ToAs and the time information. The BS estimates the distances between the BS, the RS and the MS using the propagation delays, and controls transmission power according to the estimated distances.

Abstract: A frequency resource operating apparatus and method for transmitting and receiving data at a different hopping pattern speed according to a CSI in a BWA communication system are provided. In a method of transmitting and receiving data using CSI in a mobile communication system, a BS sets the CSI of an MS to an initial CSI and sends data to the MS according to the initial CSI. The MS sends a downlink CSI to the BS. The BS groups the MS based on the downlink CSI and sends data to the MS according to a hopping pattern for the group of the MS among hopping patterns preset for predetermined groups.

Abstract: A frame configuration method and apparatus for sending data via an RS in a broadband wireless communication system are provided. In the reception mode, the RS monitors reception of data in an (n?1)th frame from an MS and reception of data in an nth frame from a BS. The RS classifies the data received from the MS and the data received from the BS as combinable data to be sent in combination or as non-combinable data to be sent separately, and stores the classified data distinguishably. When the RS transitions to a transmission mode, it determines whether to XOR-operate or mask the stored data. If the stored data can be masked, the RS XOR-operates the stored data and sends the masked data to the BS and the MS.

Abstract: Provided is an apparatus and method for communicating a frame in a multi-hop relay cellular communication system. When communicating at a Relay Station (RS), a Downlink (DL) signal is received from a Base Station (BS) and the received DL signal is reconfigured during a first section of a frame. The reconfigured DL signal is transmitted to a Mobile Station (MS) during a second section of the frame. During a third section of the frame, a UL signal is received from the MS and is reconfigured. The reconfigured UL signal is transmitted to the BS during a fourth section of the frame. The RS recovers data from the BS to retransmit only specific data corresponding to the BS. Accordingly, unnecessary retransmission can be prevented and thus resources can be used efficiently.