Abstract: A method (20,200) and apparatus (10) for detecting and identifying spectrum opportunities, including the steps of communicating a location of at least one node (12) to at least one base station (14) (24), transmitting a list of at least one channel from the at least one base station (14) to the at least one node (12) (26), and sensing the at least one channel from the list by the at least one node (12) (34). The method (20,200) also includes the steps of determining if the at least one channel is in use, and if the at least one channel is in use, determining the user of the at least one channel that is in use (38).

Abstract: The application discloses a method and apparatus for dynamic spectrum allocation to a secondary communication system seeking to operate within the spectrum of a regulated primary communication system. The method includes clustering a plurality of secondary devices based on an operating frequency utilized by each of the secondary devices. The method then includes assigning sensing opportunities to the plurality of clustered secondary devices. The method then includes, receiving sensing information from each of the clustered secondary devices. The sensing information indicates at least one of an occupied channel frequency and an unoccupied channel frequency in the spectrum. The method further includes determining at least one spectrum opportunity, in the spectrum, that is unoccupied by each of a plurality of primary devices based on the received sensing information, and allocating the at least one spectrum opportunity to at least one of the secondary devices.

Abstract: A group of nodes used for sensing in a cooperative sensing communication system (100) are selected from nodes (104-112) associated with a base station (102) operating in secondary communication mode. The group has a spatial diversity gain, as determined by a cooperative sensing index (306) that initially meets a minimum threshold. To optimize the spatial diversity gain, nodes not in the initial set are individually added to the set (408), and the index is recomputed (608). The additional node having the highest effect on spatial diversity is added to the group (614). To maintain group size, each of the original nodes is individually removed from the group (706) and the index is recomputed (708) with each initial node removed to determine which of the initial nodes provided the smallest spatial gain contribution, and is removed from the group (714).

Abstract: A device receives a signal and, prior to demodulating the signal determines whether carrier is present in the received signal based on the correlation depth of the received signal. The device determines a plurality of values for the received signal that indicate the amount of correlation in the received signal and detects the presence of the carrier in the received signal as a function of the plurality of values. The plurality of values can include autocorrelation values and prediction coefficients, wherein the autocorrelation values are estimated based on an autocorrelation function derived for the received signal, and the prediction coefficients are generated using a prediction model that is derived as a function of the autocorrelation values. The prediction coefficients can be summed to generate a decision statistic that is compared to a detection threshold to detect the presence of the carrier.

Abstract: A combination of subscriber clustering and link interleaving provides a cognitive radio system (CR) 100 with opportunities to sense an incumbent system's spectrum on secondary basis. The CR system (100) uses clustering to identify out-of-band channels. The CR system (100) uses link interleaving during a second mode of operation to sense and detect any incumbent (120) on in-band channels. A list of out-band channels are sensed by clusters (0, 1, 2, 3) sequentially to generate a ranked list of potential channels for future use by the CR system. These out-of-band channels can be used opportunistically in case of in-band incumbent detection.

Abstract: A technique for spectrum sensing management and control for a secondary communication system seeking to utilize another communication system's spectrum is provided (600). Sensor control data is sent from a base station to subscriber units (604). Sensing measurements are taken and sent back to the base station for ranking (608) as sensed feedback information. Comparisons of the sensed feedback information are made to each other and to thresholds aligned with the types of measurements taken (610). An initial ranked channel list is generated (612). Weighting of the initial ranking list and secondary ranking list is followed by re-ranking the channels according to the weighting into a final ranking list (612). The final ranking list is transmitted to the mobile units to enable operation within the other communication system's spectrum within interfering with that system (614). The weighting is based on the type of sensing measurement taken as opposed to the channel.

Abstract: A technique for a secondary communication system to utilize spectrum designated to another (or primary) communication system is provided. By ranking a plurality of secondary base stations based on base station transmit power, calculated required transmit power and path loss, a set of criteria is developed for selecting a highest ranked secondary base station for operation within a primary's spectrum. The ranking may be adapted based on mobility of the secondary's subscriber; and as such the secondary system communicates within the primary's spectrum using the adaptively ranked base stations. Channel selection may also be ranked. The technique and apparatus allows a cognitive radio (CR) network to operate within an incumbent network's spectrum.

Abstract: Systems and methods for managing power consumption in a device include toggling an ON-OFF setting of apparatus, which controls a carrier detector. The toggling is carried out according to a first duty cycle having a fixed OFF-time duration and a first dwell time having a first dwell time duration during which the carrier detector performs radio frequency carrier detection function. The device receives at least one input that affects the radio frequency carrier detection function, and the first duty cycle is changed to a second duty cycle. The toggling is carried out according to the second duty cycle, which has the same fixed OFF-time duration of the first duty cycle and a second dwell time having a second dwell time duration that is longer than the first dwell time duration, during which the radio frequency carrier detection function is performed.

Abstract: A cooperative sensing technique (300) operates by selecting a group of subscribers (302) from a secondary system, measuring a cooperative sensing metric (306) and then using the metric to identify an achievable spatial diversity gain for the group of selected subscribers (308). Once an achievable spatial diversity gain is determined for the group (308/412), it is compared to a required spatial diversity gain (310), and if the condition is met at (310), the validated group can begin spectrum sensing (314) to identify a vacant/suitable channel for operation. If the achievable spatial diversity gain is insufficient, then a new group of users is selected (312) within the secondary system and the process repeats itself.

Abstract: A method of dynamically allocating RF communication channels to a wireless communication device (102). A plurality of dynamic spectrum allocation (DSA) channels (222, 224) can be identified. The DSA channels can be channels that are available to a non-incumbent user to be used for RF communications. Based on at least one required channel parameter, a DSA channel can be selected as a first channel to allocate to the wireless communication device. At least a second channel can be selected to allocate to the wireless communication device based on a spectral relationship between the first channel and the second channel to ensure that the first and second channels are separated by at least a minimum required frequency separation (216).

Abstract: A narrowband communication system (100) includes a base station (102) and a plurality of subscriber units (104). The base station assigns one or more wideband channels to be measured to each subscriber unit (606). The subscriber units tune to their assigned wideband channels and perform narrowband measurements, then report the results to the base station (612). The base station then analyzes the measurement results (614) and selects available wideband channels to be divided into narrowband channels for use by the narrowband system.

Abstract: A method (300, 400) and a communication system (104, 106, 200) for dynamic RF spectrum allocation among a plurality of RF transmitters (108, 110, 112). A message can be received from a first communication system. The message can include a request (130) for available RF spectrum over which to transmit RF signals. The message can indicate a geographic location of a first non-incumbent transmitter (112) associated with the first communication system. Further, for the RF spectrum, a maximum power level can be determined at which the first non-incumbent transmitter may transmit without exceeding a threshold level of interference at least one focal point (134). A RF spectrum list (138) identifying at least the RF spectrum and the determined maximum power level can be communicated to the first communication system.

Abstract: A method (400) and system (100) for a wireless multi-hopping communication system is provided, wherein the system (100) includes an access point (102), a source node (CR1), and a plurality of nodes. The source node (CR1) is in communication with the access point (102), and configured to transmit a signal on at least one of a plurality of frequencies. The plurality of nodes are in communication with the access point (102) and the source node (CR1), and configured to transmit a signal on at least one of the plurality of frequencies, wherein the source node (CR1) and the plurality of nodes are adapted to determine a routing path utilizing at least one intermediate node (CR2) of the plurality of nodes and a transmitting frequency of the plurality of frequencies while reducing interference to a primary user of the transmitting frequency.

Abstract: A monitoring device (141) can include a transceiver (202) to receive a radio signal, and a controller (203) communicatively coupled to the transceiver to detect an infringement on the radio signal and report the infringement to a database. One or more policies within the database can be updated to mitigate the infringement. The monitoring device can also detect whether a cognitive radio (111) is generating interference on a primary spectrum used by an incumbent device (151). Other embodiments are disclosed.

Abstract: A remote station communicates with a base station over a secondary radio channel. During communication, the remote station determines channel conditions of the secondary radio channel. Based on the channel conditions, the remote station selects one or more sensing methods to be performed on the secondary radio channel. The result of performing the sensing method is used to determining whether an incumbent signal is present on the secondary radio channel.

Abstract: A wireless communication network is provided in which a plurality of radio devices achieve frequency diversity. By utilizing cognitive capability within the radio devices to iteratively select frequency sets, a lowest cardinality frequency set is generated and used to communicate amongst the plurality of radio devices. Each radio device can have different hardware, as the iterative selection of frequency set can take into account the different hardware capabilities of the radio devices.

Abstract: Efficient frequency spectrum sharing between at least one incumbent communication system(s) (102, 152) and at least one cognitive radio (CR) system (105) is provided. The incumbent system's system parameters and CR system's operational requirements are copied to a mirrored database (106B). The mirrored database (106B) is controlled by a either a central authority (108) or a database manager having delegated authority (508). The mirrored database (106B) is accessed by the CR system (105). The mirrored database (106B) can be modified and updated by the central authority (108) or delegated database manager (508) to correct for interference detected in the incumbent system caused (152) by the cognitive radio system (105). The cognitive radio system (105) utilizes the updated mirrored database (106B) to avoid interfering with the incumbent system (102, 152) to determine CR system operating parameters thus enhancing the ability to share spectrum.

Abstract: A group of nodes used for sensing in a cooperative sensing communication system (100) are selected from nodes (104-112) associated with a base station (102) operating in secondary communication mode. The group has a spatial diversity gain, as determined by a cooperative sensing index (306) that initially meets a minimum threshold. To optimize the spatial diversity gain, nodes not in the initial set are individually added to the set (408), and the index is recomputed (608). The additional node having the highest effect on spatial diversity is added to the group (614). To maintain group size, each of the original nodes is individually removed from the group (706) and the index is recomputed (708) with each initial node removed to determine which of the initial nodes provided the smallest spatial gain contribution, and is removed from the group (714).

Abstract: The application discloses a method and apparatus for dynamic spectrum allocation to a secondary communication system seeking to operate within the spectrum of a regulated primary communication system. The method includes clustering a plurality of secondary devices based on an operating frequency utilized by each of the secondary devices. The method then includes assigning sensing opportunities to the plurality of clustered secondary devices. The method then includes, receiving sensing information from each of the clustered secondary devices. The sensing information indicates at least one of an occupied channel frequency and an unoccupied channel frequency in the spectrum. The method further includes determining at least one spectrum opportunity, in the spectrum, that is unoccupied by each of a plurality of primary devices based on the received sensing information, and allocating the at least one spectrum opportunity to at least one of the secondary devices.

Abstract: A method of dynamically allocating RF communication channels to a wireless communication device (102). A plurality of dynamic spectrum allocation (DSA) channels (222, 224) can be identified. The DSA channels can be channels that are available to a non-incumbent user to be used for RF communications. Based on at least one required channel parameter, a DSA channel can be selected as a first channel to allocate to the wireless communication device. At least a second channel can be selected to allocate to the wireless communication device based on a spectral relationship between the first channel and the second channel to ensure that the first and second channels are separated by at least a minimum required frequency separation (216).