Patent application number | Description | Published |
20090149208 | Method and apparatus to select collaborating users in spectrum sensing - In a first time interval TI a first frequency band FB is pseudorandomly selected from a designated spectrum, and a first analysis result is determined by sensing the first FB during the first TI and then transmitted. In a second TI a second FB is pseudorandomly selected from the designated spectrum, and a second analysis result is determined by sensing the second FB during the second TI and then transmitted. Where multiple devices do this the entire spectrum is sensed, each band by a subset of devices that changes at each TI, and so any unused or underutilized spectrum is searched by the collaborative spectrum sensing, which avoids propagation problems such as fading. Also, a central node can assure various collaborating users report different FBs in different TIs such that the subset of reporting users changes for at least one of the bands in each subsequent reporting TI. Sensing and communication can be performed in different portions of the same network defined transmission time interval. | 06-11-2009 |
20090197626 | Method and apparatus to operate a cognitive radio in a crowded collaborative system - In a cognitive radio environment with at least three cognitive radio terminals, terminals | 08-06-2009 |
20100054352 | Correlation-based detection in a cognitive radio system - Samples are extracted from a received signal. For each of a plurality of candidate cyclic frequencies, cyclic covariance of the received signal is determined using a Fourier transform FT having a length that is less than the number of extracted samples. The frequency channel within which the signal was received is chosen for opportunistic/cognitive radio transmissions when none of the plurality of candidate cyclic frequencies exhibits a peak that exceeds a threshold, or results are transmitted for collaborative sensing. The extracted samples may be filtered and decimated prior to executing the FT, and the length of the FT depends on the number of samples that remain. Decimating is at a rate that depends on a bandwidth of the filtering. The bandwidth of filtering is determined by the lowest cyclic frequency where the signal to be detected exhibits cyclostationarity. Each of the candidate cyclic frequencies are near zero and determining the covariance employs a windowing function centered on zero cyclic frequency. | 03-04-2010 |
20120129462 | COGNITIVE RADIO - An apparatus configured to operate under cognitive radio principles. The apparatus includes a processor configured to perform spectrum sensing in the apparatus to produce spectrum sensing data; and first circuitry configured to share the spectrum sensing data with other apparata. | 05-24-2012 |
Patent application number | Description | Published |
20080292032 | Arrangements for interference mitigation utilizing estimation - A method is disclosed for interference mitigation which can include receiving a signal having a data component, an interfering component and a time period and creating a first plurality of digitized data that represents at least a portion of the interfering component. The method can also include generating a polynomial equation that is related to the at least a portion of the interfering component and generating a second plurality of digital data that represents a data vector of the received signal. The method can further subtract the polynomial equation from the received signal to cancel at least a portion of the interfering component to provide an interference mitigated signal representing the data component. | 11-27-2008 |
20080292033 | Arrangements for acquiring and using data obtained from received interference to facilitate data recovery - In some embodiments a method is disclosed for detecting periodic interference and predicting future interference times. The method can include detecting an arrival time of a first occurrence of interference and detecting an arrival time of a second occurrence of interference. The method can include transmitting preemptive interference mitigation control signals that anticipate future arrival times of interference. A system is disclosed that includes a periodicity detector, an interference profiler and a mitigation control module. The system can provide interference mitigation features to a data recovery system. Other embodiments are disclosed. | 11-27-2008 |
20080292034 | Arrangements for interference mitigation utilizing recursive estimation - A method is disclosed that includes receiving a signal having a data vector component and an interfering component and creating a first set of digitized data that represents the interfering component. The method can also generate a polynomial equation based on the first set of digitized data and generate a second set of digitized data that represents a data vector component of the received signal. The polynomial equation can be subtracted from the received signal to cancel at least a portion of the interfering component and provide an interference mitigated signal representing the data vector component. An error in the interference mitigated signal can be determined and the interference mitigated component can be recalculated based on the error. Other embodiments are also disclosed. | 11-27-2008 |
20080299932 | Arrangements for narrow band interference detection - A method is disclosed for mitigating narrowband interference within a system for wideband communications. The method can include separating a wideband signal into a plurality of sub bands, detecting energy levels in the sub-bands, and activating a control signal if the energy levels of the sub-bands differ by a predetermined amount. Such a difference in energy levels can indicate that narrowband interference is present and interference mitigation features can be activated. In another embodiment, a system is disclosed that has a band splitter and a plurality of energy level detectors to detect energy differences in the sub bands. Other embodiments are also disclosed. | 12-04-2008 |
20090252178 | Method, apparatus and computer program for self-adjusting spectrum sensing for cognitive radio - A cognitive radio determines a frequency channel of a spectrum, determines from a locally stored association of individual channels to either of at least two categories (e.g., in use and backup, other is a third category) a selected category for the determined frequency channel. From the selected category is determined a time at which to sense the determined frequency channel. The determined frequency channel is then sensed at the determined time and results of the sensing may be transmitted. Timers may be associated with each of the categories and adjusted based on density of cognitive nodes. A timer for the in use category is shortest, a timer for the other category is longest, and a timer for the backup category is between shortest and longest. | 10-08-2009 |