Abstract: Dynamic frequency selection based on CR is provided. A CR BS detects an interference-free and unused frequency band. When sensing a new BS that has great signal strength and requires the frequency band during communications in the frequency band, the CR BS releases the frequency band and dynamically selects another frequency band to avoid interference.

Abstract: An explicit outband signaling method for detecting sharable resources for management of public resources in a wireless network supporting Cognitive Radio (CR) technology. To this end, the invention transmits state information for the current channel to a CR system in order to enable communication of the CR users, whose communication with the CR system is impossible due to an influence of an incumbent system, thereby allowing the CR system to stop the use of the interference channel, and to provide a corresponding service with another channel.

Abstract: A cooperative diversity method and apparatus that can minimize interference and maximize an efficiency of a transmission channel between terminals of a cooperative diversity pair, the method including: determining a pair of terminals to be a cooperative diversity pair according to a spectrum sensing result of a cognitive radio (CR); selecting a subchannel through which data is exchanged between the pair of terminals; and transmitting the data between the pair of terminals through the selected subchannel.

Abstract: A communication initialization method at a MAC layer in a CR wireless communication system is provided. The use or non-use of a frequency band is sensed over a broadband with a minimized sensing time in a non-interfering manner with existing communication systems.

Abstract: A resource management method in a Cognitive Radio communication system where at least two Base Stations of heterogeneous networks provide a connection service to Mobile Stations within their service areas is provided. In the method, at least one BS having candidate resources broadcasts its candidate resource information on the downlink of a system information channel. At least one BS lacking in resources searches the downlinks of system information channels from neighbor heterogeneous networks, selects an offer BS among the BSs having candidate resources, and rents resources from the selected offer BS by negotiations.

Abstract: A method of partitioning resources in a CR wireless communication system and a system supporting the same are provided. A new BS receives radio resource status information from a prior BS using a particular frequency band, and requests resource partitioning to the prior BS using a new uplink subchannel defined for communications between BSs. Resource negotiation messages are exchanged over a channel defined between the two BSs so as to efficiently partition resources between the BSs.

Abstract: A communication method and apparatus for a distributed network system where a cognitive radio (CR) technology is used. A communication method of a distributed network system where the CR technology is used includes transmitting adjacent channel information, from at least one first neighbor node adjacent to a source node, first adjacent channel information of the at least one first neighbor node using a pulse signal according to a request of the source node; by transmitting, from at least one second neighbor node adjacent to a destination node, second adjacent channel information of the at least one second neighbor node to the destination node using a pulse signal according to a request of the destination node; and exchanging data between the source node and the destination node using a channel that is not currently used, according to the transmitted adjacent channel information.

Abstract: A communication method and apparatus of a cognitive radio (CR) environment using a relaying system while not interfering with a communication system having a priority right to use a frequency band, the communication method including: listening to fundamental channel (FCH) information and/or downlink/uplink (DL/UL) map information of a frame transmitted in the relaying system; obtaining a transmission signal of the relaying system using the FCH information and/or the DL/UL map information; orthogonally encoding data to be transmitted in the CR environment based on the obtained transmission signal; and transmitting the orthogonally encoded data via a determined channel that is used in the relaying system. Accordingly, aspects of the present invention can retrieve radio resources unused in the CR environment more easily.

Abstract: A method and apparatus of controlling a transmission power of a cognitive radio (CR) environment, the method including: sensing an incumbent user that uses a same channel as the CR environment; detecting signal quality information of the sensed incumbent user; calculating, using the detected signal quality information, a maximum transmission power value that corresponds to a maximum transmission power that may be transmitted by a CR base station in the CR environment; and controlling a communication of the CR environment to be performed within the calculated maximum transmission power value.

Abstract: A signaling method between a cognitive radio (CR) base station and a CR terminal in a CR environment, and a channel division method used for the signaling method, includes: detecting a channel usage of an incumbent system, which communicates with a CR base station; sensing an outband channel to communicate with the CR base station; receiving an EOS, which is broadcasted from the CR base station via the outband channel according to a predetermined period; and transmitting a sensing report signal with respect to the channel to the CR base station.

Abstract: A communication method and apparatus for a distributed network system where a cognitive radio (CR) technology is used. A communication method of a distributed network system where the CR technology is used includes transmitting adjacent channel information, from at least one first neighbor node adjacent to a source node, first adjacent channel information of the at least one first neighbor node using a pulse signal according to a request of the source node; by transmitting, from at least one second neighbor node adjacent to a destination node, second adjacent channel information of the at least one second neighbor node to the destination node using a pulse signal according to a request of the destination node; and exchanging data between the source node and the destination node using a channel that is not currently used, according to the transmitted adjacent channel information.

Abstract: A method and apparatus of controlling a transmission power of a cognitive radio (CR) environment, the method including: sensing an incumbent user that uses a same channel as the CR environment; detecting signal quality information of the sensed incumbent user; calculating, using the detected signal quality information, a maximum transmission power value that corresponds to a maximum transmission power that may be transmitted by a CR base station in the CR environment; and controlling a communication of the CR environment to be performed within the calculated maximum transmission power value.

Abstract: Aspects of the present invention relate to a communication method and apparatus in a cognitive radio (CR) environment, the method including: receiving an uplink signal that is repeatedly transmitted via at least one candidate channel that is not being used; determining whether the receiving of the uplink signal is due to an existence of an incumbent user using a CR channel of the target cell; and changing the CR channel of the target cell when the receiving of the uplink signal is due to the existence of the incumbent user using the CR channel of the target cell.

Abstract: A communication method and apparatus of a cognitive radio (CR) environment using a relaying system while not interfering with a communication system having a priority right to use a frequency band, the communication method including: listening to fundamental channel (FCH) information and/or downlink/uplink (DL/UL) map information of a frame transmitted in the relaying system; obtaining a transmission signal of the relaying system using the FCH information and/or the DL/UL map information; orthogonally encoding data to be transmitted in the CR environment based on the obtained transmission signal; and transmitting the orthogonally encoded data via a determined channel that is used in the relaying system. Accordingly, aspects of the present invention can retrieve radio resources unused in the CR environment more easily.

Abstract: A cooperative diversity method and apparatus that can minimize interference and maximize an efficiency of a transmission channel between terminals of a cooperative diversity pair, the method including: determining a pair of terminals to be a cooperative diversity pair according to a spectrum sensing result of a cognitive radio (CR); selecting a subchannel through which data is exchanged between the pair of terminals; and transmitting the data between the pair of terminals through the selected subchannel.

Abstract: A signaling method between a cognitive radio (CR) base station and a CR terminal in a CR environment, and a channel division method used for the signaling method, includes: detecting a channel usage of an incumbent system, which communicates with a CR base station; sensing an outband channel to communicate with the CR base station; receiving an EOS, which is broadcasted from the CR base station via the outband channel according to a predetermined period; and transmitting a sensing report signal with respect to the channel to the CR base station.

Abstract: Dynamic frequency selection based on CR is provided. A CR BS detects an interference-free and unused frequency band. When sensing a new BS that has great signal strength and requires the frequency band during communications in the frequency band, the CR BS releases the frequency band and dynamically selects another frequency band to avoid interference.

Abstract: A resource management method in a Cognitive Radio communication system where at least two Base Stations of heterogeneous networks provide a connection service to Mobile Stations within their service areas is provided. In the method, at least one BS having candidate resources broadcasts its candidate resource information on the downlink of a system information channel. At least one BS lacking in resources searches the downlinks of system information channels from neighbor heterogeneous networks, selects an offer BS among the BSs having candidate resources, and rents resources from the selected offer BS by negotiations.

Abstract: A method of partitioning resources in a CR wireless communication system and a system supporting the same are provided. A new BS receives radio resource status information from a prior BS using a particular frequency band, and requests resource partitioning to the prior BS using a new uplink subchannel defined for communications between BSs. Resource negotiation messages are exchanged over a channel defined between the two BSs so as to efficiently partition resources between the BSs.

Abstract: A communication initialization method at a MAC layer in a CR wireless communication system is provided. The use or non-use of a frequency band is sensed over a broadband with a minimized sensing time in a non-interfering manner with existing communication systems.