Abstract: A method for transmitting feedback information for cooperative transmission in a wireless communication cellular system comprises: receiving information on cells that can be cooperatively transmitted from a base station; determining cells that prefer the cooperative transmission among the cells that can be cooperatively transmitted; generating feedback information, which includes a preference cell indicator representing preferred cells and non-preferred cells for the cooperative transmission among the cells that can be cooperatively transmitted, precoding matrix information for the respective cell that can be cooperatively transmitted, phase information representing a phase correction value of each of the preferred cells for the cooperative transmission, and a channel quality indicator; and transmitting the feedback information through a control channel or a data channel.

Abstract: A wireless communication system using multiple channels is provided. An apparatus includes an allocator for, when bursts are allocated to an Accessing Terminal (AT) which utilizes a plurality of channels at the same time, allocating the same amount of the bursts to each channel in use; a generator for, when a map message to be transmitted in a primary channel of the AT is generated, generating the map message which comprises allocation information of the bursts allocated to the AT; and a transmitter for transmitting the map message in the primary channel of the AT.

Abstract: Provided are an apparatus and a method for transmitting a CBP packet for communication information sharing between base stations in a CR-based wireless communication system. In the method, a CBP packet including a CBP identifier is transmitted to a base station of adjacent cells via one SCW slot. A CBP identifier list for successfully received CBP packets is received from the base station of the adjacent cells. When the CBP identifier is included in the CBP identifier list, the SCW slot is occupied.

Abstract: A method and apparatus reduce overhead of feedback in a closed loop Multiple Input Multiple Output (MIMO) system. A controller feeds back the long-term Precoder Matrix Index (PMI) to a serving base station under direction of the serving base station when the long term PMI feedback transmission is required, generates a new codebook using the long term PMI, and determines a short term PMI from the new codebook. A feedback transmitter feeds back the short-term PMI to the serving base station.

Abstract: An apparatus and method for transmitting Coexistence Beacon Protocol (CBP) in a cognitive radio system are provided. The apparatus includes a detector, a controller, and a transmitter. The detector scans channels on which neighboring Base Stations (BSs) operate through a plurality of directional antennas. The controller links the plurality of directional antennas with BSs, respectively. The transmitter receives a CBP packet through the directional antenna linked with the BS, and transmits the received CBP packet to at least one or more other BSs linked with at least one or more other directional antennas.

Abstract: A base station includes an apparatus and a method for exchanging frequency channel resources between base stations in a Cognitive Radio (CR) based communication system. A requesting Base Station (BS), which requests channel exchange a neighboring BS, receives a channel advertisement message from a neighboring BS and sends a channel exchange request message to the neighboring BS. The channel exchange request message includes at least one of a neighbor BS Identifier (ID), a requesting BS ID, channel information for the channel exchange at the requesting BS, and channel information exchangeable at the neighboring BS. The requesting BS receives a channel exchange response message from the neighboring BS in response to the channel exchange request message, determines whether to execute a channel exchange process to the neighboring BS based on information in the received channel exchange response message, and sends a channel exchange reply message indicative of the determination result.

Abstract: An apparatus and a method for transmitting a Coexistence Beacon Protocol (CBP) packet in a Cognitive Radio (CR) wireless communication system are provided. In the method for transmitting CBP packet in a transmitter that operates in a scalable Orthogonal Frequency Division Multiple Access (OFDMA) mode, a priority is given to each channel of one or more channels based at least partly upon channel use statuses of two or more neighbor Wireless Regional Area Networks (WRANs). Whether a Quality of Service (QoS) for CBP packet transmission for each channel is met is sequentially determined according to the respective priority. A channel having a highest priority is selected from the one or more channels meeting the QoS as a channel for CBP packet transmission. A CBP packet is transmitted via the selected channel.

Abstract: A method and apparatus for transmitting/receiving reference signals in Long Term Evolution (LTE) and LTE-Advanced (LTE-A) systems includes determining whether a dedicated reference signal is detected in a current subframe; estimating, if a dedicated reference signal is detected in the current subframe, a data channel using the dedicated reference signal to receive data; and estimating, if no dedicated reference signal is detected in the current subframe, a data channel using a common reference signal detected in the current subframe to receive data. The transmission scheme uses a DeModulation Reference Signal (DM-RS) for channel response estimation. To secure backward compatibility of the LTE-A system, a Common Reference Signal is transmitted in normal subframes.

Abstract: Methods and apparatus are provided for scheduling in a communication system. A Coordinated Multi-point Transmission/Reception (CoMP) set of cells is determined for a terminal that supports a CoMP function. An indicator for use in scheduling one or more cells in the CoMP set and cell information corresponding to the indicator are transmitted to the terminal. Scheduling information with the indicator is transmitted to the terminal.

Abstract: A method for allocating resources of a common control channel includes determining a carrier type, allocating, when the carrier is backward compatible, resources for a Physical Control Format Indicator CHannel (PCFICH), and allocating resources for a common control channel with a dedicated reference signal based on a Physical Resource Block allocated for the PCFICH. A UE can receive the common control channel without extra signaling by mapping the common control channel to the frequency resource based on the cell-specific parameter or channel.

Abstract: Methods and apparatus for receiving a first control channel and a second control channel in a wireless communication system are provided. Control information for receiving the second control channel from a base station is received through higher layer signaling. A second control channel resource is determined from an entire control channel resource based on the control information. A first control channel resource is determined from the entire control channel resource according to the second control channel resource.

Abstract: A method and system for resource allocation for data and control channels is provided. A downlink transmission method of a base station in a the system includes determining, by the base station, whether resources for a terminal are restricted; determining a sub-set of resource blocks for the terminal from among all resource blocks, if the resources for the terminal are restricted; transmitting information about the sub-set of the resource blocks to the terminal; and allocating a first sub-sub-set of the sub-set of the resource blocks for control channel transmission, and a second sub-sub-set of the sub-set of the resource blocks for data channel transmission.

Abstract: A new structure of user-specific reference signals design is provided. Higher spectrum efficiency is achieved, and two users may share the same resource for control signal transmission in a distributed antenna system via different distributed antennas. In addition, search space overlapping is enabled and thus control resource reuse is made possible.

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: 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.