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48 results about "Circular correlation" patented technology
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Device and method for correcting error estimation of analog-digital converter
ActiveCN104993827AThe number of effective sample points is smallReduced duration requirementsAnalogue-digital convertersAnalogue/digital conversion calibration/testingNumerical controlDigital down converter
Owner:NO 24 RES INST OF CETC
IQ imbalance compensation method based on Golay complementary sequences
InactiveCN103581078AMulti-frequency code systemsTransmitter/receiver shaping networksCommunications systemGolay complementary sequences
The invention belongs to the technical field of wireless communication and particularly relates to an IQ imbalance compensation method based on the Golay complementary sequences, wherein the IQ imbalance compensation method is applied to a wireless communication system which is disturbed by IQ imbalance. The IQ imbalance compensation method based on the Golay complementary sequences comprises the steps that S1 a training sequence pair is established and sent; S2 a receiving terminal receives the training sequence pair established in the step S1 and conducts circular correlation processing on each training sequence which is received; S3 the influence of the IQ imbalance of a received signal is compensated. According to the IQ imbalance compensation method based on the Golay complementary sequence, under the condition that channel information does not need to be known, complex parameters of IQ imbalance are estimated and then IQ imbalance is compensated.
Owner:UNIV OF ELECTRONICS SCI & TECH OF CHINA
Improved logic-based track initiation method
InactiveCN103727931AHigh precisionReduce computing timePicture interpretationUsing reradiationCorrelation coefficientComputer vision
The invention provides an improved logic-based track initiation method. The improved logic-based track initiation method comprises the steps of registering a temporary track for each tracking target by taking a measuring point of the tracking target in a first frame image as an initial point, and taking the correlation coefficient of each tracking target as the correlation coefficient of the corresponding temporary track; by taking the measuring point, in the circular correlation area of measuring points of the first frame image, of a second frame image as a second point, adding into the corresponding temporary track; when one measuring point is added into the temporary track of the tracking target, accumulating the correlation coefficient of the temporary track, and when the accumulation sum of the correlation coefficients is greater than or equal to a preset judgment threshold, adding the temporary track into a queue of temporarily successful track for carrying out track pruning, and then outputting an effective track. The improved logic-based track initiation method has different track initiation requirements after different targets are achieved, the track initiation precision can be enhanced, and the calculation time can be shortened.
Owner:NANJING UNIV OF SCI & TECH
System and method for acquiring weak signals in a global positioning satellite system
InactiveUS20070046534A1Overcomes shortcomingImprove receiver sensitivityPosition fixationSatellite radio beaconingCoherent integrationCircular correlation
A method of acquiring a weak signal includes selecting a first predetection integration time (PIT) interval for processing a digital intermediate frequency (IF) signal, selecting a number of data bit edges within the PIT, computing a plurality of coherent integrations for each data bit edge, selecting a coherent integration, which corresponds to a most likely data combination for each data bit edge, from the plurality of coherent integrations, updating an incoherent integration total for each data bit edge with the coherent integration corresponding to the selected most likely data bit combination for each data bit edge, comparing the incoherent integration total for each data bit edge with a threshold after a predetermined number of steps of the coherent integration computations and incoherent integration total updates, and identifying a code delay from the incoherent integration. The method may also include determining a code delay from an estimated Doppler shift corresponding to the identified code delay. In this method, the coherent integrations are computed using a circular correlation technique that is performed in a manner so the coherent integrations are not independent from one another in successive steps. Thus, computational efficiencies may be gained from subsequent uses of coherent integrations computed during previous steps. The circular correlation is preferably performed over intervals corresponding to the separation between data bit edges.
Owner:PURDUE RES FOUND INC
Navigation signal differential acquisition method and systems therefor
A method of acquiring signals from satellites in a Global Positioning System (GPS) is disclosed. The method includes receiving navigation signals from the satellites of the GPS, down-converting to complex baseband the received navigation signals to form a first signal, digitizing samples of the first signal, nonlinear processing of the digitized samples of the first signal to form a second signal, where the nonlinear processing comprises forming a weighted sum of products of pairs of the digitized samples at different relative delays, in which one of each of the pairs has been complex conjugated, coherent averaging the second signal over integer multiples or submultiples of a spreading sequence period of the navigation signals to form a third signal, performing circular correlation processing of the third signal with a representation of each navigation signal of the navigation signals and determining a timing offset at which a correlated output energy is maximized, based on the circular correlation processing.
Owner:2201028 ONTARIO
Carrier frequency estimation method based on circular correlation entropy
ActiveCN105302940ASolving Carrier Frequency EstimationSpecial data processing applicationsEstimation methodsPeak value
The invention belongs to the technical field of circular stationary signal processing and provides a carrier frequency estimation method based on circular correlation entropy. The method comprises steps of calculating signal relative entropy and circular relative entropy through a formula, calculating circular relative entropy-spectrum via a formula, acquiring a signal circular relative entropy-spectrum projection, and estimating signal carrier frequency corresponding to a circular relative entropy-spectrum projection peak based on a relationship between a modulation system and circular frequency. The experiment proves great calculation performance of the carrier frequency estimation method; and signal carrier frequency can be estimated under a condition of coexistence of non-gaussian noise and same-frequency band interference.
Owner:DALIAN UNIV OF TECH
Time division duplexing-long term evolution (TDD-LTE) downlink synchronizing method
InactiveCN102857457ASmall amount of calculationReduce the burden onMulti-frequency code systemsCell IDCyclic prefix
The invention is applicable to the field of Time division duplexing-long term evolution (TDD-LTE) system communication and provides a TDD-LTE downlink synchronizing method. The method includes obtaining half-frame synchronization information and serial numbers in a cell identity (ID) group; determining a cyclic prefix (CP) type; subjecting a frequency domain secondary synchronization sequence to de-interleaving and descrambling to obtain an even sequence and an odd sequence respectively; subjecting the even sequence and a secondary original sequence to circular correlation and recording a coordinate corresponding to a peak value of correlation values as a first displacement coordinate; generating a third descrambling sequence according to the first displacement coordinate; descrambling the odd sequence and the third descrambling sequence, subjecting the odd sequence, the third descrambling sequence and the secondary original sequence to circular correlation, and recording a coordinate corresponding to a peak value of correlation values as a second displacement coordinate; and obtaining a cell ID group serial number and frame starting information according to the first displacement coordinate and the second displacement coordinate. According to the TDD-LTE downlink synchronizing method, m<0> and m<1> can be determined only by performing 31 times of cross-correlation calculation with the length of 31, so that TDD-LTE downlink synchronization information is obtained, and the calculation amount is greatly reduced.
Owner:SHENZHEN WINHAP COMM
Method and system for estimating two-dimensional angle-of-arrival of satellite signal
ActiveCN108957387AEstimated performance is goodImprove estimation performanceRadio wave direction/deviation determination systemsRadio wave reradiation/reflectionSignal-to-noise ratio (imaging)Signal subspace
The invention belongs to the technical field of systems measuring a direction or a deviation from a predetermined direction and discloses a method and system for estimating a two-dimensional angle-of-arrival of a satellite signal. The method comprises a step of performing initial suppression on non-Gaussian clutter by using fractional low-order circular correlation, a step of performing secondarysuppression on the non-Gaussian clutter by using an improved zero-order statistical magnitude, a step of obtaining a signal subspace by an optimization method and obtaining a three-dimensional map oftwo-dimensional angle-of-arrival estimation by a multi-signal clustering method, and a step of performing maximum value search on the three-dimensional map to obtain an estimated value of the two-dimensional angle-of-arrival in a non-Gaussian clutter scene. When a generalized signal-to-noise ratio is greater than 10 dB, a root mean square error of azimuth and pitching angle estimation is smaller than 10<-1>. That means that the system and the method have good estimation performance for the two-dimensional angle-of-arrival of the satellite signal in the non-Gaussian clutter scene under a low SNR condition, and a moving target can be tracked and located through satellite radiation source signals by using the method and the system.
Owner:XIDIAN UNIV
Channel estimator for ground digital multimedia broadcast system based on time domain relevancy
InactiveCN101106421AProcessing speedReduce usageTelevision system detailsColor television detailsFourier transform on finite groupsUnit impulse response
The invention belongs to the field of wireless digital communication technology, specifically relating to a ground digital television media broadcasting (DTMB) system channel estimator based on time domain correlation. The method of circular correlation is applied, and by using the quasi-cyclic PN (pseudo random) protection serial in the DTMB system frame structure, a channel impulse responses is obtained. Based on the CMOS technique in the standard of SMIC 0.18 micron, the channel estimator provided in the invention can work stably under the frequency of 60MHz, and the area is no more than 152k equivalent gates. Compared with the channel estimator based on fast fourier transform (FFT), the implementation scheme of channel estimation proposed in the invention reduces the design complexity by 50% on the premise of ensuring no performance loss, and the operation period reduces greatly.
Owner:FUDAN UNIV +1
Fast GPS L2C CM code capturing method
The invention provides a fast GPS L2C CM code capturing method. The method comprises the steps of carrying out full-period segmented collapsing on a local code sequence, capturing a data section as long as a local signal from received signal data, carrying out phase search by means of FFT algorithm circular correlation, carrying out theoretical analysis and formula derivation of thermal noise and collapsing noise, obtaining an accurate noise empirical formula by combining with experimental data, providing a reasonable threshold setting scheme to determine a code phase primarily according to the analysis of the signal to noise ratio of the signal, and carrying out time domain coherent processing on the primarily determined code phase after capturing succeeds to obtain a final code phase. According to the fast GPS L2C CM code capturing method, the searching speed of the phase of an L2C signal CM code is improved greatly, the phase of the CM code can be determined fast, and FFT computing amount is reduced greatly.
Owner:SHANGHAI JIAO TONG UNIV +1
System and method for acquiring weak signals in a global positioning satellite system
InactiveUS7358895B2Overcomes shortcomingImprove receiver sensitivityBeacon systemsSatellite radio beaconingCoherent integrationCircular correlation
A method of acquiring a weak signal includes selecting a first predetection integration time (PIT) interval for processing a digital intermediate frequency (IF) signal, selecting a number of data bit edges within the PIT, computing a plurality of coherent integrations for each data bit edge, selecting a coherent integration, which corresponds to a most likely data combination for each data bit edge, from the plurality of coherent integrations, updating an incoherent integration total for each data bit edge with the coherent integration corresponding to the selected most likely data bit combination for each data bit edge, comparing the incoherent integration total for each data bit edge with a threshold after a predetermined number of steps of the coherent integration computations and incoherent integration total updates, and identifying a code delay from the incoherent integration. The method may also include determining a code delay from an estimated Doppler shift corresponding to the identified code delay. In this method, the coherent integrations are computed using a circular correlation technique that is performed in a manner so the coherent integrations are not independent from one another in successive steps. Thus, computational efficiencies may be gained from subsequent uses of coherent integrations computed during previous steps. The circular correlation is preferably performed over intervals corresponding to the separation between data bit edges.
Owner:PURDUE RES FOUND INC
System and method of use for non-parametric circular autocorrelation for signal processing
A computer-implemented method to characterize a signal structure is provided. The method may receive a first set of time-dependent data vectors; select a sample size of data vectors; determine a minimum number of lags to process to characterize the first set of data vectors; calculate a cross-product term for each data vector in the sample size for each lag, a mean value and a variance value based on the sum of the cross-product term for each lag; calculate a circular correlation function for each lag; determine an upper and a lower correlation bound for the circular correlation based on the mean value, the variance value, and a desired false alarm rate; and characterize the signal structure based on the number of calculated circular correlation functions that exceed the upper or lower correlation bounds so as to generate a signal characterization data signal.
Owner:UNITED STATES OF AMERICA
Auxiliary synchronous sequence detection method and device for long-term evolution system
ActiveCN102055698ARealize detectionEqualisersMulti-frequency code systemsIsochronous signalCircular correlation
The invention relates to an auxiliary synchronous sequence detection method for a long-term evolution system. The auxiliary synchronous sequence detection method comprises the following steps of: firstly, performing fast Fourier transform (FFT) on a received auxiliary synchronous signal to convert the received auxiliary synchronous signal into a frequency domain signal; rearranging carriers; performing de-interweaving and descrambling process; performing circular correlation on the de-interweaved and descrambled signal; selecting a relevance value and an index value corresponding to the relevance value in a circular correlation result; selecting an index pair with highest credibility according to the selected relevance values; and calculating the number in a cell set according to the index pair.
Owner:LEADCORE TECH
On-orbit navigation signal IQ phase consistency calibrating method
ActiveCN106226793AAvoid Calibration ErrorsPrecise determination of phase delay relationshipSatellite radio beaconingQuadrature demodulationCoded element
The invention discloses an on-orbit navigation signal IQ phase consistency calibrating method, and belongs to the field of satellite navigation. The method includes the steps of conducting high-speed sampling for navigation radiofrequency signals, conducting quadrature demodulation for the intercepted navigation signal sampling data to obtain two roadbed band data, determining the pseudo-random code start point of a navigation signal I branch through circular correlation processing, extracting the Q-path baseband signals according to the pseudo-random code sheet interval with the half code sheet delayed than the start point, regenerating code elements of the navigation signal Q branch, conducting circular correlation respectively for the navigation signal data by using the local I branch pseudo-random code and regenerated Q branch code elements, respectively determining the pseudo-random code start points of the I branch and the Q branch in the navigation signals, and calculating the phase consistency of a navigation signaling channel in combination with sampling rate. The method is applied in a digital domain, the calibrate errors caused by self zero value error of reception equipment in conventional test equipment can be avoided, and the calibrating precision is high.
Owner:BEIJING INST OF SPACECRAFT SYST ENG
Blind estimation method for large frequency bias in ground digital television system and apparatus thereof
InactiveCN101378382AHigh speedLarge carrier frequency offset estimation rangeMulti-frequency code systemsIntermediate frequencyCarrier signal
The invention discloses a large frequency hemiopia estimation method, which is carried out according to circular correlation property of receiving data without using auxiliary data, of a digital television terrestrial broadcasting transmission system receiver and a device thereof, belonging to the processing field of digital information. The invention adopts a digital intermediate signal which is subjected to A / D sampling to be multiplied by a local carrier signal so as to carry out digital down conversion and then forms filtering by a square root raising cosine (SRRC) filter. A complex signal output by the SRRC filter is delayed for Tau sampling points and subjected to conjugation-obtaining, and the delayed and conjugated complex signal is subjected to re-multiplication with the original signal before being delayed. The result of re-multiplication is divided into p branches for summarizing, the results of the p branches are subjected to FFT of p point, and then the estimation value of the frequency offset is obtained. The invention is applicable to the frame structures of two modes: single carrier and multi-carrier, can carry out blind estimation on the frequency offset under the state without any auxiliary information, and has the advantages of large scale of frequency offset estimation, good noise immunity, being suitable for hardware realization and the like.
Owner:BEIHANG UNIV
Joint estimation method for angle of array antenna and number of signal sources in complex noise environment
ActiveCN107966676ASolve the problem that the estimation accuracy is limited by the bandwidth formReduce computational complexityRadio wave direction/deviation determination systemsComputation complexityEngineering
The invention relates to a joint estimation method for the angle of an array antenna and the number of signal sources in a complex noise environment, and belongs to the technical field of radio positioning. The joint estimation method comprises the steps of 1) solving a cycle correlation entropy matrix V<alpha><y>(tau) of array signals under a condition that the cycle frequency is known; 2) building a cycle correlation entropy array linear prediction model V=[Phi]A which is applicable to broadband signals and narrow-band signals; 3) estimating the number K of interested signal sources and an error variance [sigma]<2>; 4) estimating a flow pattern matrix of the array model; and 5) performing DOA estimation by using spectrum peak searching. According to the invention, a cycle correlation entropy theory is organically applied to array signal processing, correlation characteristics of the cycle correlation entropy are innovatively proposed, and the array linear prediction model is built based on the characteristics. The algorithm is put forward according to actual requirements, and has the characteristics of high anti-noise performance, low computation complexity, small number of required snapshots, high angular resolution and the like.
Owner:DALIAN UNIV OF TECH +1
GNSS system bit synchronization method based on phase difference matched filtering
InactiveCN104280751ASolve computational problems that are not well suited for signals with quadratic encodingLess sensitive to frequency offsetSatellite radio beaconingResource consumptionPhase difference
The invention discloses a GNSS system bit synchronization method based on phase difference matched filtering. The GNSS system bit synchronization method based on phase difference matched filtering comprises the following steps that S1, an antenna receives satellite signals and conduct frequency shift and A / D sampling quantization; S2, frequency tracking and code tracking are conducted on digital intermediate frequency signals; S3, integration and zero clearing are both conducted on the two channels of tracked I / Q signals, and relevant complex signal data X[i]=I[i]+Q[i]*j within 1ms are obtained; S4, synchronous processing is conducted on X[i]. According to the step S4, two methods are provided, wherein the first method comprises the steps that delay conjugate of X[i] is solved, Z[i]=X[i]*X<*>[i-1] is calculated, circular correlation is conducted on Z[i] and LocalCode, Z'[i] is calculated, integration is conducted on Z'[i], so that the value of V[delta] (please see the equation of V[delta] in the specification) is obtained, and then the minimum V[delta] is the bit boundary; the second method comprise the steps that Z[i]= =X[i]* X<*>[i-1]is calculated, integration is conducted on Z[i], so that the value of V[delta] (please see the equation of V[delta] in the specification) is obtained, circular correlation is conducted on Z[i] and LocalCode, the maximum correlation value in correlation results is the bit boundary. The GNSS system bit synchronization method based on phase difference matched filtering is suitable for large-frequency-offset condition, not insensitive to frequency offset and small in calculation amount, only one channel of matched filtering and one channel of noncorrelation integral are needed, and resource consumption and time consumption are small.
Owner:CHENGDU CORPRO TECH CO LTD
Frame synchronization method for burst mode OFDM system
InactiveCN102594762AMulti-frequency code systemsCommunications systemSignal-to-noise ratio (imaging)
The invention belongs to the synchronous technical field of wireless communication systems, and in particular relates to a frame synchronization method for a burst mode OFDM (Orthogonal Frequency Division Multiplexing) system. The method comprises the following steps: selecting a sequence S with an initial position d and a length N from received data; calculating a related value P of the front half part and the rear half part of the S, as well as a half (E) of an energy value of the S and a normalized related value C; computing time according to the C to judge a variable value M; comparing the M with the small one of two threshold values, if exceeding the threshold value, a maximal circular correlation value Z of the S and a training sequence T is calculated out, otherwise, the d value is updated and the first step is returned; and if the Z exceeds the larger one of the two threshold values, confirming a frame initial position, otherwise, the d value is updated and the first step is returned. According to the method provided by the invention, the influence of a platform effect on the frame synchronization of the burst-mode OFDM system is avoided. Therefore, the method can work under different signal-to-noise ratio conditions.
Owner:UNIV OF ELECTRONICS SCI & TECH OF CHINA
Method and device for detecting secondary synchronization code of long term evolution (LTE) system
ActiveCN103037411AImprove detection efficiencyRadio transmission for post communicationWireless communicationTime domainCarrier signal
The invention provides a method and a device for detecting a secondary synchronization code of an LTE system. The method comprises the steps of receiving a secondary synchronization signal of a time domain, converting into a frequency domain signal, and rearranging carrier waves; conducting de-interleaving and descrambling processing for the result to obtain a group of correlation sequences 0 and eight groups of correlation sequences 1; conducting circular correlation for the results to obtain related values; selecting a plurality of related values from related values of the group of correlation sequences 0 and obtaining a plurality of 0 sequence index values corresponding to the plurality of related values, and selecting a plurality of related values from related values of the eight groups of correlation sequences 1 and obtaining a plurality of 1 sequence index values corresponding to the plurality of related values; forming a plurality of index pairs through the plurality of 0 sequence index values and the plurality of 1 sequence index values, judging the plurality of index pairs, and selecting a plurality of index pairs from the plurality of index pairs; and according to the selected plurality of index pairs, obtaining a plurality of cell group numbers, so that the cell detection efficiency is improved.
Owner:LEADCORE TECH
Steady adaptive waveform beam formation algorithm under pulse and Gaussian noise
ActiveCN108416105AExact cycle frequencyRobust BeamformingSpatial transmit diversityDesign optimisation/simulationComputation complexityCorrelation function
The invention belongs to the technical field of array antennas, and provides a steady adaptive waveform beam formation algorithm under pulse and Gaussian noise. The invention puts forward the steady adaptive waveform beam formation algorithm under two noises including Gaussian and pulse and a complex environment of same-frequency interference by considering the practical situation of a circulationfrequency error. The method comprises the following steps that: under a situation that a known expectation signal has a circulation error frequency of error estimation, calculating the output signaland the reference signal of each sampling point; on the basis of a maximum related entropy criterion, estimating a guiding vector; and utilizing the related function of the related entropy of the output signal to estimate the accurate circulation frequency of the expectation signal so as to realize steady wave beam formation. By use of the algorithm, the circulation related entropy theory is applied to a wave beam formation research, and the maximum related entropy criterion is used for constructing a solving formula of the guiding vector and the circulation frequency. The specific algorithm is put forward according to practical requirements and has the characteristics of high anti-noise performance, low calculation complexity, small required snapshot number, high waveform formation robustness and the like.
Owner:DALIAN UNIV OF TECH
Method of Processing a Received Channel Signal in a Device to Device Communications Link
ActiveUS20210076433A1Mitigate and/or obviate problemsSynchronisation arrangementBaseband system detailsTelecommunicationsResource block
Described is a method of decoding a physical sidelink shared channel (PSSCH) involving physical sidelink control channel (PSCCH) resource grid search space reduction, timing offset (TO) estimation, and reference symbol identification. Resource grid search space reduction may include identifying resource blocks (RBs) having a signal power below a first threshold such that said RBs can be excluded from further processing. Search space reduction may additionally or alternatively include identifying RB pairs where a difference in signal power between the RBs comprising each pair of RBs is above a second threshold and excluding any such said RB pairs from further processing. TO compensation may include circularly correlating TO-compensated received DMRSs and their corresponding local DMRSs to obtain energy or power profiles. From the energy / power profiles, a subset L of highest stored power values and their corresponding cyclic shift (ncs) values can be chosen where said power values are equal to or exceed a third threshold. The selected subset L can be made available for use in a decoding process for a received channel signal.
Owner:HONG KONG APPLIED SCI & TECH RES INST
Method and apparatus for correlating two data sections
InactiveCN101405804ALow data rateSmall scaleSpeech analysisRecord information storageData segmentHuman auditory system
Watermarking of audio signals intends to manipulate the audio signal in a way that the changes in the audio content cannot be recognised by the human auditory system. The watermark data are decoded from the received watermarked audio signal by correlation with corresponding candidate reference sequences. One or more of the sync symbols (S1, S2, S3) are embedded twice in the watermark data frame in the encoder. Thereafter a circular correlation is calculated instead of a standard correlation.
Owner:THOMSON LICENSING SA
Answer selection method and device based on holographic neural network and electronic device
InactiveCN108984475AImprove accuracyNatural language data processingNeural architecturesSummary dataTheoretical computer science
The present application relates to an answer selection method and device based on a holographic neural network and an electronic device. The method comprises the following steps: acquiring question data and answer data, wherein the answer data comprises title data and summary data; obtaining a problem hidden state sequence, a title hidden state sequence and an abstract hidden state sequence by two-way long-short-term memory layer processing; connecting the title hidden state sequence and the abstract hidden state sequence to obtain the answer hidden state sequence; performing circular correlation operation on the hidden state sequence of the question and the hidden state sequence of the answer to obtain the holographic combination vector; and obtaining the correlation score of the answer data with respect to the question data based on the holographic combination vector by using the multiple perceptron model. In this way, the deep semantic information can be extracted through two-way long-short-term memory network, and the correlation feature between question data and answer data can be found through holographic combination vector, so that the accuracy of answer selection can be improved.
Owner:北京慧闻科技(集团)有限公司
Navigation signal differential acquisition method and systems therefor
A method of acquiring signals from satellites in a Global Positioning System (GPS) is disclosed. The method includes receiving navigation signals from the satellites of the GPS, down-converting to complex baseband the received navigation signals to form a first signal, digitizing samples of the first signal, nonlinear processing of the digitized samples of the first signal to form a second signal, where the nonlinear processing comprises forming a weighted sum of products of pairs of the digitized samples at different relative delays, in which one of each of the pairs has been complex conjugated, coherent averaging the second signal over integer multiples or submultiples of a spreading sequence period of the navigation signals to form a third signal, performing circular correlation processing of the third signal with a representation of each navigation signal of the navigation signals and determining a timing offset at which a correlated output energy is maximized, based on the circular correlation processing.
Owner:2201028 ONTARIO
GNSS (Global Navigation Satellite System) signal capturing method and device and computer storage medium
PendingCN114690214AImplement searchReduce pointsSatellite radio beaconingCarrier signalCoherent integration
The invention provides a GNSS (Global Navigation Satellite System) signal capturing method and device, and the method comprises the steps: carrying out the 1 / N-time code rate sampling of a spreading code, compressing the length of the spreading code into L, controlling the length of each segment to be L when the satellite data is segmented, and carrying out the frequency mixing with a local carrier wave, thereby obtaining zero-frequency data; searching a satellite data NH code phase, stripping an NH code from each segment of data, and performing coherent integration to obtain a compressed satellite signal with two spread spectrum period lengths; respectively carrying out FFT operation, complex number multiplication and IFFT operation on the processed spreading code and satellite data to obtain a cyclic correlation result; solving a modulus of the result and searching a maximum value, if the maximum value exceeds a preset first threshold, judging that coarse capture is successful, and calculating a satellite signal code phase, a Doppler value and an NH code phase; code phase accurate search is carried out at a 1 / 2 chip interval in left and right N / 2 ranges by taking a roughly captured satellite signal code phase as a center. The method is low in hardware resource consumption, and the capture signal-to-noise ratio and the capture code phase precision can be improved.
Owner:西安开阳微电子有限公司
Method for adaptively acquiring P codes on basis of averaging technology
The invention provides a method for adaptively acquiring P codes on the basis of an averaging technology. The method is an algorithm for quickly directly acquiring the P codes on the basis of circular correlation theories, each N points in pseudo code sequences of received signals are sequentially subjected to averaging processing to form a new sequence, local pseudo code sequences are subjected to similar processing to form a new sequences, each two corresponding new sequences are subjected to circular correlation processing, particular code intervals where code elements in the received signals are located can be judged when correlation peak values are higher than judgment thresholds, and the exact positions of the code elements can be determined. The method is equivalent to the basic averaging technology when the signals are high in intensity and has the advantage of calculation economization.
Owner:CHANGAN UNIV
A method for capturing CL codes of GPS L2C signals
InactiveCN103592663BReduce pointsShorten detection timeSatellite radio beaconingSignal-to-noise ratio (imaging)Coherent integration
The invention provides a method for capturing CL codes of GPS L2C signals. According to the method, coarse acquisition is conducted on the GPS L2C signals with low signal to noise ratio, a time-frequency domain double-folding technology is adopted in the coarse acquisition process, data length is compressed, and then the folding section where a synchronization pseudo code phase position is placed is obtained through FFT circular correlation operations and threshold detection; the FFT circular correlation operations and threshold detection are adopted in the refined acquisition process, an accurate pseudo code phase position is obtained, and the entire acquisition is completed. By the adoption of the method, by the way of folding, the CL codes with large code length are shortened, so that the number of points of each FFT operation are greatly decreased, meanwhile, coherent integration time is prolonged, and precision is improved; by the way of double-folding, the acquisition is divided into the coarse acquisition and the refined acquisition, detection time is shortened, detection precision is improved, and high practical value is achieved.
Owner:SOUTHEAST UNIV
Method and device for confirming the disturbance code relativity in the code division multi-address system
InactiveCN101034911AReduce complexitySmall amount of calculationMultiplex code allocationCodes simulation/testingIt equipmentCode division multiple access
The invention supplies a method to determine harass code relevancy in the code division multiple access (CDMA) system and its equipment, among, the method includes: calculates the compound wide frequency harass code of each harass code; calculates the circular correlation of the compound wide frequency harass in two harass code, obtains 961 entries 16 values long related sequences; according to maximum value appearance position in the states correlation sequence, calculates the average maximum value of the 961 entries correlation sequence; in view of each related sequence in first five and the latter four elements, computes the mean value to obtain the element average value, calculates the mean value of the 961 entries element average value to obtain the sum element average value; The average maximum value and the sum element average value carry on weighting addition, obtains the two code relevant correlative value. The amount of invention calculation is small, only need one-off calculates and the preservates, the invention is one kind the symbol mutually disturbs with between the network in and various plotsactually tallies, complex is small, also the convenient measuremethod.
Owner:ZTE CORP
Method for identifying networks in electric power wireless communication isomeric multi-network coexistence environment
ActiveCN104283649AAccurate identificationImprove recognition accuracyError prevention/detection by using return channelError detection/prevention using signal quality detectorPrior informationSlide window
The invention provides a method for identifying networks in an electric power wireless communication isomeric multi-network coexistence environment. The method comprise the following steps that firstly, network signals are monitored, MAC protocol characteristics of the network signals are identified through an improved sliding window energy detection method, and the frame length of the network signals is identified for the networks based on frame transmission; secondly, a circular correlation spectrum of the network signals monitored in the first step is obtained according to a multi-period weighted circulation stable characteristic detection method, and the time-frequency characteristics of the network signals are identified according to distribution of spectrum peaks of the circular correlation spectrum; thirdly, the MAC protocol characteristics and the time-frequency characteristics of the monitored network signals are compared with known network signal characteristics, and the type of the monitored network signals is identified. By means of the method, prior information is not needed in the identifying process, the accurate rate of identification is high, and the method is extremely high in adaptability to identification of the networks in the electric power wireless communication isomeric multi-network coexistence environment.
Owner:STATE GRID CORP OF CHINA +2
Time division duplexing-long term evolution (TDD-LTE) downlink synchronizing method
InactiveCN102857457BSmall amount of calculationReduce the burden onMulti-frequency code systemsCyclic prefixCell ID
Owner:SHENZHEN WINHAP COMM
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