59 results about "Spectrum occupancy" patented technology

Systems, methods, and apparatuses are provided for coarse-sensing modules that are operative for providing initial determinations of spectrum occupancy. The coarse-sensing modules may include a wavelet waveform generator providing a plurality of wavelet pulses, and a multiplier that combines the wavelet pulses with an input signal to form a correlation signal. The coarse sensing modules may further include an integrator that receives the generated correlation signal from the multiplier, where the integrator determines correlation values from integrating the correlation signal, and a spectrum recognition module in communication with the integrator that determines an available spectrum segment based at least in part on the correlation values. In addition, the spectrum recognition module may determine an available spectrum segment by utilizing information from a spectrum usage database, where the spectrum usage database includes information associated with one or more known signal types.

The invention provides a compressed spectrum sensing method based on autocorrelation matrix reconstitution and mainly solves the problem that an existing sensing algorithm is high in sampling speed and large computation overhead. The compressed spectrum sensing method comprises that a secondary user obtains an observation sequence of a frequency spectrum environment through compressed sensing and obtains an autocorrelation matrix estimated value of Nyquist sampling by utilizing autocorrelation vector quantity of a autocorrelation matrix reconstitution Nyquist sample sequence of the observation sequence; a multi-signal classification MUSIC algorithm is adopted to obtain an estimated value of occupied channel number according to a characteristic value of the autocorrelation matrix estimated value; a characteristic spectrum is constructed according to the characteristic value and the estimated value of the occupied channel number, spectral amplitude values corresponding to characteristics of channels are added to obtain a sum, and mark numbers of the occupied channels are judged. By means of the compressed spectrum sensing method, the sampling speed of a secondary user receiving machine can be reduced, algorithm complexity at the reconstitution end is low, and spectral amplitude occupying situation in a cognitive radio system can be judged quickly.

Systems and methods for determining minimal spectrum occupancy in routing and wavelength/spectrum assignment (RWA/RSA) in an optical network include performing, for a new demand request, a set of binary operations using a binary representation for each wavelength or portion of spectrum over all links in the optical network; and selecting, based on the set of binary operations, i) a route and ii) one of a) a wavelength and b) one or more portions of spectrum for the new demand request.

One embodiment of the invention discloses a method for realizing compatible coexistence of a newly-built NGSO constellation communication system and an existing NGSO constellation communication system. The method comprises the following steps that a satellite of the newly-built NGSO constellation communication system performs control-level signaling interaction with a ground user station through afirst signaling beam, wherein the combined coverage range of the signaling beam of each satellite in the newly-built NGSO constellation communication system ensures that at least one re-coverage range is realized on the earth surface; a newly built NGSO constellation communication system satellite performs service communication with the ground user station through a first user beam, wherein a spot beam of each satellite is controlled to point to different wave positions in different time slots, the fixed wave position forms a first range, and the first range is consistent with the re-coveragerange; and the ground user station acquires current available spectrum resources, and sends position information and spectrum occupation information to the satellite covering the user station throughthe first signaling beam.

In an embodiment of the invention, a system may include a specially configured computer having at least one processor and at least one storage device. The computer may be configured to calculate an estimate of radio propagation and signal strength using a first radio propagation model. The computer may recalculate the estimate of radio propagation and signal strength using one or more additional radio propagation models. The computer may store the recalculated estimate of radio propagation and signal strength in storage.

The invention relates to a clustering cooperative spectrum sensing method for a cognitive radio network, belonging to the technical field of cognitive radio. The method comprises steps of firstly, dividing all sensing users in the cognitive network into a plurality of clusters, and selecting a cluster head of each cluster; then, the sensing users in each cluster sensing the spectrum occupation condition of the local through energy detection, and the cluster head sending the sensed energy detection information to the cluster head for data fusion processing; after data fusion, the cluster head sending a judgment result to a fusion center for data fusion; and finally, the fusion center estimating the signal to noise ratio of each cluster head, comparing the signal to noise ratio with an average value of the signal to noise ratio of all clusters, and finally sensing, according to a comparison result, whether a master user occupies the spectrum. Theoretically, the method can effectively lower the effect of path loss and attenuation on performance detection, the topological structure is easy to manage, and the method is applicable to a large scale cognitive radio network with complicated channel environment.

The invention belongs to the technical field of cognitive radio, and particularly relates to a frequency spectrum prediction sensing method based on an RCS-GRU model. The method comprises the following steps: simulating a channel by adopting an M/M/N queuing theory model; combining and splicing the channel state sequences simulated in the step 1 into a matrix; establishing a convolutional neural network model based on residual CBAM, inputting the spliced channel state matrix set into the model, and extracting features of spectrum occupancy states among channels; inputting the extracted feature data set into a GRU model, mining the features of the channel state in the time sequence, performing spectrum prediction, and outputting the channel state of the next time slot; adopting an Adam optimization algorithm to set a variable learning rate optimization cross loss function to train an RCS-GRU network, and adding a dropout method in the training process; and evaluating the prediction performance of the RCS-GRU by adopting a relation curve of the false alarm prediction probability and the detection prediction probability and a root mean square error (RMSE).

A broadband weighted cooperative spectrum sensing algorithm for resisting intelligent SSDF attacks comprises: firstly, recognizing malicious users by analyzing the characteristics of the intelligent attacks of the malicious users and combining energy preprocessing and principal component analysis; secondly, the center node establishing a reputation model according to the historical and current spectrum judgment results of each neighbor node in the sliding time window, and updating the reputation value of the reputation model in real time; and finally, performing group sparse joint reconstruction based on a prior condition by utilizing the identified observation vector set, and accurately obtaining the spectrum occupation condition of each sub-channel. Simulation results show that comparedwith a traditional R-WCCSS algorithm, the spectrum detection probability of the algorithm under the intelligent SSDF attack is improved by 16.7%, the cooperative spectrum sensing performance of the cognitive network is remarkably improved, and efficient spectrum sharing is achieved.

The invention discloses a method for measuring a spectrum occupancy rate based on a signal moment characteristic. The spectrum occupancy rate is measured by a relation among a channel occupancy rate p of a signal, a relative mean value muR of two moment characteristic signals and a relative variance sigmaR<2> of the signals. Spectrum signals within a specified frequency range are continuously scanned and sampled in a measurement period; an mean value mu and a variance sigma<2> of the signals of each channel are iteratively computed in a time sequence; an mean value muN and a variance sigmaN<2> of the background noise of each channel in the spectrum are obtained; and then the spectrum occupancy rate p of the signals of each channel is obtained. The method overcomes the disadvantages that the prior art sets a threshold according to the experiences, can only measure the signals with a signal-to-noise ratio greater than 15dB, stores a large amount of data and computes in an off-line manner; the provided method is less affected by the signal-to-noise ratio, the strength of the signal and the background noise, sets the threshold without manual operation, achieves quick on-line computation, has small storage and automatically computes the spectrum occupancy rate. The method can be widely applied to the fields of radio monitoring, shared spectrum access and the like.

Provided is an ultra wide band radio-frequency signal generating method and device based on double driving modulators. Corresponding Gaussian pulse signals are adjusted on two phase modulators of the double driving modulators, and then relative time delay, signal amplitude and relative phase shifting between the two Gaussian pulse signals are respectively controlled, so that a transverse electric mode which passes through a polarization controller generates ultra wide band radio-frequency signals through the double driving modulators. According to the method and device, four different kinds of UWB pulse signals which comprise one-order UWB pulse signals, two-order UWB pulse signals, three-order UWB pulse signals and high-order UWB pulse signals can be generated. Meanwhile, the generated first three kinds of signals can meet the requirement of the frequency occupying range of UWB pulse signals given by FCC, accordingly, the complexity degree of a flexible UWB pulse signal generating device is greatly lowered, cost is low, and UWB pulse signals can be generated easily and flexibly.

A statistical method for dynamic spectrum occupancy measurement. The implementation steps are as follows: 1) with the sampling step f3, performing M (img file= '998175DEST_PATH_IMAGE001. TIF' wi= '19' he= '20'/) for monitoring frequency band (img file= '991539DEST_PATH_IMAGE 002. TIF 'wi=' 19 'he=' 19 '/) sub-spectrum monitor sampling, The returned sample values are column vector snapshots (img file= '683552DEST_PATH_IMAGE003. TIF' wi= '139' he= '26'/); 2) The receiver interference tolerance is (img file= '420563DEST_PATH_IMAGE004. TIF' wi= '26' he= '19'/). For frequency points (img file= '881632DEST_PATH_IMAGE005. TIF' wi= '21' he= '23'/), the field strength (img file= '311476DEST_PATH_IMAGE006. TI F 'wi=' 24 'he=' 24 '/) to compare and determine that interference tolerance value (img file =' 553102DEST_PATH_IMAGE004. TIF 'wi=' 26 'he=' 19 '/), Take (img file= '765908DEST_PATH_IMAGE007. TIF' wi= '47' he= '24'/), If (img file= '409379DEST_PATH_IMAGE008. TIF' wi= '63' he= '24'/), then(img file= '183694DEST_PATH_IMAGE009. TIF' wi= '44' he= '22'/); 3) sample snapshots were divide into (img file = '912615DEST_PATH_IMAGE010. TIF' wi= '17' he= '18'/) groups, Data matrices (img file= '991430DEST_PATH_IMAGE010. TIF' wi= '17' he= '18'/) were obtained (img file= '427090DEST_PATH_IMAGE011. TI F 'wi=' 23 'he=' 20 '/), Select near (img file= '198737DEST_PATH_IMAGE005. TIF' wi= '21' he= '23'/) (img file= '87059DEST_PATH_IMAGE012. TIF' w i= '33' he= '19'/), is a (img file= '218832DEST_PATH_IMAGE010. TIF' wi= '17' he= '18'/) data matrix (img file= '571315DEST_PATH_IMAGE013. TIF 'wi=' 22'he=' 25 '/); 4) Dynamically set the threshold level of the frequency point (img file= '451547DEST_PATH_IMAGE005. TIF' wi= '21' he= '23'/) (img file= '889481DEST_PATH_IMAGE 014. TIF 'wi=' 35 'he=' 26'/) and determine possession, take (img file=' 636331DEST_PATH_IMAGE015. TIF 'wi=' 50 'he=' 23 '/); If (img file= '108901DEST_PATH_IMAGE016. TIF' wi= '65' he= '26'/), then (img file= '160034DEST_PATH_IMAGE017. TIF' wi= '46' he= '26'/); (img file= '85264DEST_PATH_IMAGE018. TIF' wi= '20' he= '25'/) is (img file= '745790DEST_PATH_IMAGE005. TIF' wi= ' 21 'he=' 23 '/) correspond to that field strengthvalues in the data matrix (img file =' 807287DEST_PATH_IMAGE013. TIF 'wi=' 22 'he=' 25 '/); 5) Statistical spectrum occupancy (img file= '91638DEST_PATH_IMAGE005. TIF' wi= '21' he= '23'/) (img file= '441848DEST_PATH_IMAGE019. T IF 'wi=' 140 'he=' 37 '/). This method realizes the measurement and statistics of dynamic spectrum occupancy, reduces the monitoring time, improves the calculation precision, and can effectively reflect the occupancy of different frequency bands in real time.

The invention provides a spectrum feature visualization device and a spectrum feature visualization method, used for displaying time occupancy rates and space occupancy rates of comprehensive frequency and different industrial utilization frequency, and a maximum value, a minimum value and an average value of level/field intensity from different angles such as frequency domain, space and time by using charts. Measurement on the spectrum occupancy rate is performed by using a Poisson distribution mathematical model, the situation that the measured spectrum occupancy rate has a reasonable confidence interval can be ensured, furthermore, in the case of same confidence level and relative accuracy, the quantity of sampling points is much less than that of the sampling points in the prior art, particularly under the condition of high occupancy.

Since the influence of different spectrum occupancy characteristics of an authorized user on detection performance is not considered in the existing cognitive radio spectrum detection interval adjusting method, the invention provides a cognitive radio spectrum detection interval adjusting method based on channel characteristics. The cognitive radio spectrum detection interval adjusting method comprises the steps of determining a change parameter lambda of detection intervals according to different spectrum occupancy characteristics of an authorized user and making the detection interval change according to a growth curve alpha= K * (1-exp (-lambda * t)), and increases the adaptability of algorithms while reducing detection cost. The cognitive radio spectrum detection interval adjusting method can detect the appearance of the authorized user, can detect whether the user exits a channel in good performance, and further increases the channel utilization rate.