Abstract: A frame structure, a method, and an apparatus for inter-frame resource sharing in a Cognitive Ratio (CR) communication system are provided. An apparatus for sharing a channel in an environment where a plurality of CR communication systems coexist, constitutes a Superframe Control Header (SCH), in one superframe, that includes a frame allocation MAP for frame information allocated to a Base Station (BS), with respect to each BS, and transmits and receives the SCH at the start frame of the frames allocated to the BSs.

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 wireless communication system based on a Cognitive Radio (CR) is provided. A method includes checking channels unused by a licensed system through a spectrum sensing; selecting one of the channels unused by the licensed system as a control channel based on a channel quality per channel; and transmitting control information to terminals within a cell over the control channel.

Abstract: A method and apparatus for channel management in a Cognitive Radio (CR) system supporting multiple channels are provided. The method includes generating a candidate channel set from an available channel list, configuring a backup channel set by combining at least one candidate channel, and updating the backup channel set when a channel change event occurs. Accordingly, the multiple channels can be effectively used in CR communication.

Abstract: An apparatus and a method for joint power control in a wireless communication system are provided, in which customer premise equipments to be serviced are selected by scheduling, upon receipt of service requests from the customer premise equipments, the interference level of each of the selected customer premise equipments that affects an incumbent system is calculated, a total interference level affecting the incumbent system is calculated by summing the interference levels of the selected customer premise equipments, and a transmit power of the each customer premise equipment is reduced, if the total interference level is larger than a threshold.

Abstract: An apparatus and a method for selecting a candidate channel to change an operating channel so as to minimize effect of interference in a wireless communication system using a Cognitive Radio (CR) function are provided. The method includes confirming an operating channel of at least one neighbor cell and candidate channel set to a third group by the neighbor cell; setting a candidate channel used as the operating channel of the neighbor cell among at least one candidate channels changeable to the operating channel, to a third group of lowest priority; setting candidate channels set to the third group of the neighbor cell among candidate channels not set to the third group, to a second group; and setting candidate channels set to neither the second group nor the third group, to a first group of highest priority.

Abstract: Provided is an apparatus and method for controlling power in a cognitive radio wireless communication system, the method comprising: performing channel scheduling and the first power control for at least one terminal; checking whether the at least one terminal exist within constraint area, and determining whether the at least one terminal within constraint area cause interference to incumbent system; and performing the secondary power control so that an allocating power may be less than the maximum tolerable interference.

Abstract: A method of operating a Data Base (DB) server for storing spectrum condition information on a licensed system in a Cognitive Radio (CR)-based wireless communication system and a CR-based wireless communication system are provided. The method includes determining changes in the spectrum condition information on the licensed system, recalculating maximum Equivalent Isotropically Radiated Power (EIRP) allowed for each channel of CR-based devices registered in a list, and transmitting information regarding the recalculated maximum allowed EIRP.

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: A method and apparatus for estimating a geo-location of a terminal in a wireless communication system are provided. In a method of operating a terminal for providing geo-location information in a cognitive ratio (CR) system, the method includes obtaining first ranging information and transmitting a first ranging code to a base station (BS) in a network entry process; receiving an allocated second ranging resource from the BS; and transmitting a second ranging code.

Abstract: A signal detection apparatus and method in a Multiple Input Multiple Output (MIMO) wireless communication system are provided. The apparatus includes a receiver for receiving training symbol vectors and a data signal vector from a transmitting end through a plurality of receive (Rx) antennas and a detector for expanding the training symbol vectors into second- or higher-order polynomials, for generating a weighting parameter vector for multivariate polynomial expansion of the data signal vector by using the polynomials expanded from the training symbol vectors and thereafter for expanding the data signal vector into a second- or higher-order multivariate polynomial using the weighting parameter vector, and for detecting Transmit (Tx) values of the data signal vector from the multivariate polynomial. Therefore, signal detection performance in a Multiple Input Multiple Output (MIMO) wireless communication system resembles that of a non-linear scheme while complexity resembles that of a linear scheme.

Abstract: A system and method for transmitting and receiving a signal in a communication system using a relay scheme. A base station receives a first signal in a first time interval from a first mobile station which is at least one mobile station located in a third region which is a region where a first region which is a region of the base station itself overlaps with a second region which is a region of a relay station. The relay station receives a second signal in the first time interval from a second mobile station which is at least one mobile station located in a fourth region which is a region not overlapping with the first region in the second region, and receives the first signal from the first mobile station. The relay station transmits a third signal including the first signal and the second signal to the base station in a second time interval. The base station receives the third signal in the second time interval, and cancels the first signal from the third signal to detect the second signal.

Abstract: A ranging apparatus in a communication system is provided. A terminal generates a ranging code for ranging with a base station, maps the ranging code to at least one sub-carrier so the ranging code is repeated in a time domain, generates a ranging signal so the mapped ranging code has a size of one symbol interval, and transmits the generated ranging signal to the base station. The base station receives a ranging signal, extracts a half signal of a valid symbol interval of the ranging signal, generates a valid symbol interval signal by repeating the extracted half signal of the valid symbol interval, restores a ranging signal using the valid symbol interval signal, and performs ranging using the ranging signal.

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 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: A Relay System (RS)-based cellular network transmission method for MT having a function of single input and single output is provided. The method includes transmitting broadcast information to all RSs and Mobile Terminals (MTs); transmitting required data to each RS in an Orthogonal Frequency Division Multiplexing (OFDM) mode; performing the operations of selection of modulation scheme, addition of CP, addition of symbols for channel estimation and selection of OFDM symbols; feeding feedback information to the Base Station (BS); transmitting a synchronization request to the BS; transmitting a synchronization acknowledgement to the RS; transmitting information to each MT belonging to the BS; transmitting information to each MT belonging to the RS; the MT belonging to the BS transmitting ACK/NACK information to the BS; the MT belonging to the RS transmitting ACK/NACK information to the BS; and the BS informing the RS of the received ACK/NACK information.

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 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: 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: A method and apparatus for joint unicast using multi-user superposition coding in a wireless relay system are provided. A BS superposition-encodes first and second data messages directed to first and second MSs, respectively, scheduled at a current scheduling instant. The first and second data messages carry first and second information bit streams for the first and second MSs, respectively. The first MS has a relatively good direct link to the BS, and the second MS has a relatively bad direct link to the BS. The superposition-coded data is transmitted to the first MS and an RS connected between the BS and the first and second MSs. The RS receives the superposition-coded data from the BS, extracts the second information bit stream by decoding the superposition-coded data, and transmits a third data message carrying the second information bit stream to the first and second MSs.