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: Allocation of channels in a dedicated frequency spectrum on a secondary basis. A direct mode communication request (150) from a first wireless communication device (112) can be received and processed to determine whether there are one or more secondary communication channels over which direct mode communication may be implemented between the first wireless communication devices and other wireless communication devices (114, 116, 118) without violating at least one communication policy for the secondary communication channel. Use of a secondary communication channel can be assigned or denied. In addition, a direct mode communication request can be communicated from a wireless communication device to a base transceiver station (104) identifying one or more other communication devices for which direct mode communication is requested.

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 (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 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 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: 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: Efficient frequency spectrum sharing between at least one incumbent communication system(s) (102, 104) and at least one cognitive radio (CR) system (106, 108) is provided. The CR unit includes OFDM detection (216) for detecting the presence of OFDM signals which indicate the presence of an incumbent communication system within the shared spectrum. The CR system (106) updates channel occupancy information in response to the detected OFDM signals so as not to interfere with the incumbent communication systems (102, 104).

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: In a network comprising a plurality of channels, at least two channels are operating at different frequencies. The fixed network equipment (FNE; 124, 126) identifies a plurality of channels present at a serving site and classifies each channel into one of a plurality of bandwidth groups. All the channels in a given bandwidth group have common roaming characteristics. The FNE periodically broadcasts information relating to at least one channel in each bandwidth group present at the serving site. The FNE further identifies least one channel present at an adjacent site. Each channel present at the adjacent site is also classified in one of the plurality of bandwidth groups. The FNE broadcasts information on loading for each bandwidth group present at the adjacent site.

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 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 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 method for the selection of forward error correction (FEC)/constellation pairings (800) for digital transmitted segments based on learning radio link adaptation (RLA) including formatting a packet transmission having a predetermined number of information bits (801). The packet is then split into a plurality of segments (803) where an RLA is used (805) to determine the optimum format of the packet. The plurality of segments is then sent to a channel encoder for FEC encoding and symbol mapping (807) at a rate selected by the RLA. The segments are then formatted into packet blocks (809) and transmitted in blocks that form a time slot at a constant symbol rate.

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: A system (100) and method (500) for method for channel slot granting is provided. The method includes estimating (502) a temperature of a device (102), adjusting (504) a duty-cycle of the device based on the temperature, sending (506) the duty-cycle to a base station (110) and allocating (510) time slots for the device in accordance with the duty-cycle. A rate of slot assignments to multiple devices can be controlled (512) based on multiple duty-cycles received. The duty-cycle and temperature can be included (610) in a Quality of Service (QoS) metric for inbound and outbound performance.

Abstract: A method for maximizing intermodulation interference protection during a handoff between radio cell sites (300) includes scanning a plurality of radio channels (302) and measuring the signal power (307, 315) for at least one of the radio channels. One or more receiver attenuators (313) are then set based on the detection of intermodulation (IM) interference of the measured channel. The attenuators are then scaled (311) based on the degree of IM interference. If the attenuators cannot mitigate this interference below some predetermined level, the radio channel is changed (321) and the process begins again to ensure a high quality of communication with a cell site.

Abstract: A method and system for synchronizing scan opportunities in a mobile communications system. Time slots are sent between a mobile subscriber and an associated base station wherein the mobile subscriber corresponds to a scan group. The number of time slots sent between the mobile subscriber and the associated base station is counted. Based upon the count, the scan group of the mobile subscriber, a scan rate, and a scan opportunity divisor, a scan opportunity is determined. If it is a scan opportunity, a scan is performed of a neighboring base station.

Abstract: A method for maximizing intermodulation interference protection during a handoff between radio cell sites (300) includes scanning a plurality of radio channels (302) and measuring the signal power (307, 315) for at least one of the radio channels. One or more receiver attenuators (313) are then set based on the detection of intermodulation (IM) interference of the measured channel. The attenuators are then scaled (311) based on the degree of IM interference. If the attenuators cannot mitigate this interference below some predetermined level, the radio channel is changed (321) and the process begins again to ensure a high quality of communication with a cell site.