82 results about "Impulse function" patented technology

This disclosure describes a distributed reader architecture for a mobile computing device such as cellular telephone handset. This architecture includes a reader library that reads device capabilities and business model parameters in the device, and in response, for selects an appropriate configuration of reader modules for identifying a content item. The reader modules each perform a function used in identifying a content item. The modules are selected so that the resources available on the device and in remote devices are used optimally, depending on available computing resources on the device and network bandwidth. One example of a reader module is a fast watermark detection module that quickly detects the presence of a watermark, enabling resources to be focused on portions of content that are most likely going to lead to successful content identification. A watermark signal structure for fast watermark detection is comprised of a dense array of impulse functions in a form of a circle in a Fourier magnitude domain, and the impulse functions having pseudorandom phase. Alternative structures are possible.

The invention relates to a non coherent demodulation method, which belongs to the signal processing field, is used in Chirp spread spectrum technology demodulation, can reduce phase shift error, multipath time delay error and Doppler shift effect, and achieves better performance over multipath fading channels and IEEE802.15.4a S-V standard channels. The fundamental principle of the invention is: utilizing a Chirp signal as an impulse function in a proper fractional Fourier domain, i.e. fractional Fourier transformation achieves an excellent focusing ability to the Chirp signal sent by the CCS system. For the advantage of Chirp signal processing in fractional Fourier transformation, the fractional Fourier transformation can be used in CSS spread spectrum technology to demodulate Chirp signals with different modulation frequencies. The demodulation to CCS system is realized by implementing fractional Fourier transformation to the received base band data, and judging the code element by detecting the peak value of the focusing order. The method reduces the demand to frequency synchronization, needs no phase synchronization, and achieves better performance over multipath frequency selectively fading channels.

The invention discloses a distributed sensing system based on a weak Bragg reflection structure. The distributed sensing system comprises a SG-DBR (Screen Grid-Distributed Bragg Reflector) tunable laser (1), an electrooptic modulator (4), an opto-isolator (5), an optical circulator (6), and weak Bragg reflection cycle structural optical fibers (7), which are connected in turn; wherein the SG-DBR tunable laser (1) is controlled by a wavelength tuning control circuit (2), the electrooptic modulator (4) is controlled by an impulse function generator (3), a photo-detector (8) is connected with the optical circulator (6), control signals outputted by the wavelength tuning control circuit (2) and the electrooptic modulator (4) and electric signals outputted by the photo-detector (8) enter a data acquisition card (9) jointly, and are processed and then transmitted to a data processing device (10). The distributed sensing system realizes the long-distance distributed sensing alarm for parameters such as temperature, stress and vibration, and has the characteristics of higher detection sensitivity and positioning precision, easiness for realization, lower cost and reliability for operation.

The invention provides a method for realizing a synthetic aperture radar echo simulator. The method comprises the following steps: carrying out C language programming on a computer according to a synthetic aperture radar target impulse function generating algorithm, after loading radar parameters, target parameters and motion platform parameters, calculating a target impulse function, generating a data file and storing the data file; and utilizing the echo simulator to receive the transmitting signal of the radar, carrying out convolution calculation with the target impulse function so as to obtain the target echo signals of the radar in different positions, and sending the echo signal out through digital-to-analogue conversion. By utilizing the method, the system resource consumption of target impulse function calculation is relieved, so that the system realization complexity is reduced; and moreover, the target echo signal is transmitted in real time through the convolution calculation of a high-speed digital processing platform, so that the ground test requirements of the synthetic aperture radar are satisfied.

A method and apparatus are disclosed that apply multiuser detection (MUD) analysis to an aggregated RF response from a plurality of simultaneously queried RFID tags, so as to distinguish the individual tag responses. The claimed method thereby significantly reduces RFID detection latency when multiple tags are simultaneously queried. Some embodiments transmit carrier waves at more than one frequency, such as a plurality of equally-spaced frequencies, so as to enhance the MUD analysis by incorporating a multi-frequency dimension. Other embodiments incorporate additional spatial dimensions by deploying multiple RF detection antennae at separated locations. The number of colliding tag responses must be estimated before MUD analysis can be applied. In some embodiments other signal parameters must be estimated, such as signal bias and an impulse function for each responding tag that characterizes alterations of the RF signal while in transit due to propagation distance, passage through intervening objects, and reflections.

The invention relates to an automatic registering and fused splicing method of multiple images. The unordered images are enhanced in a multi-dimension Retinex method; the images match each other by utilizing a logarithm polar coordinate transformation improved phase correlation algorithm, zooming, rotation and translation parameters are calculated, an overlapped area among the images is estimated roughly, and an ordering rule is formulated according to energy peak values of an impulse function; an SUFR algorithm is used to extract characteristic points from the overlapped area to be registered, a random sampling consistent algorithm is improved to purify matching point pairs accurately, model parameters are optimized, a transformation matrix among the images is established, and sequential images are spliced successively; and an NSCT algorithm is utilized, a fusion strategy is made to further fuse spliced images, and a spliced image after fusion is output. The method of the invention can be used to reduce influence of difficult manual ordering, fuzzy image details, low resolution, high noise, nonuniform illumination and the like on image registration and splicing, provides help for reducing cost of imaging equipment and accurate diagnosis of medical staff, and has good application prospects in the medical image assisted field.

The method obtains an interference detection result by detecting sampled digital signals in real time in a transform domain, then maps the interference detection result into an interference suppression pulse function on the basis of a unit noise pulse function, and carries out interference suppression filtering in the transform domain according to the interference suppression pulse function. The present invention is capable of detecting narrowband interference such as monotone, frequency modulation, and phase modulation interferences in a receive channel adaptively in real-time, and suppressing the interference adaptively according to the quantity, energy and bandwidth of the interference, so as to reduce the influence of the interference. Therefore, the present invention may enhance robustness of the communication system against interference. Moreover, the present invention does not need multiple notch devices, costs low and may be implemented simply and reliably.

The invention discloses a phase-sensitive optical time domain reflection system based on self-mixing technology, which is composed of an optical path detection part and a circuit demodulation part. The optical path is composed of a narrow linewidth laser (1), an optical coupler (2), an acoustic-optical degree modulator (3), a pulse function generator (4), a circulator (5), an optical fiber (6) and a polarization controller (7). The circuit is composed of a bandpass filter (10), a low-noise amplifier (11), a power divider (12), a frequency mixer (13) and a low-pass filter (14). As the simple self-mixing structure is adopted, demodulation on modulated signals can be realized, and inconvenient demodulation caused by frequency drift of a local optical signal can be eliminated. In the phase-sensitive optical time domain reflection technology system by adopting a coherent detection method, frequency drift of local light is a problem which needs to be considered. Influences brought by frequency drift of the local light can be well eliminated. The device is stable in work, and the vibration position and the vibration frequency can be accurately measured in multiple times of measurement.

The invention provides a match filtering method and a device used for a synthetic aperture laser radar nonlinear chirp. The method comprises the following steps: an additional reference channel is arranged outside a target channel, the frequency domain conversion result of the quadratic high-order terms in heterodyne receiving signal phase difference of the reference channel is corrected so as to lead the index quadratic term of the frequency domain signal and the index quadratic term in the frequency domain signal in the target channel to form an index conjugated pair, and subsequently the convolution operation is carried out to the corrected frequency domain signal in the reference channel and the frequency domain signal in the target channel (wherein, the index quadratic term becomes a pulse function after being multiplied), thus overcoming the effects of the laser source nonlinear chirp. The method and the device overcome the nonlinear chirp phase error of the laser source and improve the range resolution of the synthetic aperture laser radar imaging.

This invention discloses one device to integrate handle impulse generator and bus machine bed control panel, which comprises the following parts: handle impulse function module to process handle impulse generator input signals; PLC function module to control machine bed control panel input and output; physical layer control module to control communication between upper machine with physical layer interface; bus agreement analysis module to analyze information data.

The present invention provides a horizontal set image segmentation method of a frequency-domain boundary energy model. The method comprises a step of carrying out Fourier transform on the contour inner and outer areas of an input image, a step of designing a frequency-domain filter to filter the contour inner and outer areas so as to extract a boundary energy term, a step of taking a horizontal set function regular term, a length constraint term and the boundary energy term as an overall energy items, a step of combining a step function and an impulse function, using a horizontal set method to minimizing the energy item, and thus obtaining an ideal segmentation result. According to the horizontal set image segmentation method of a frequency-domain boundary energy model, a band-pass filter and an optimal filter are used to extract object boundary information, other interference information such as strong noise, a bias field and regular texture are eliminated, the smoothness of a segmentation result boundary can be controlled, and the high precision segmentation result of a medical image with strong noise and a bias field at the same time can be obtained.

The invention discloses a ternary binary fractal wavelet sparse diagnosis method for rolling bearing faults, and relates to a mechanical fault diagnosis method. The method comprises: carrying out multi-scale iterative decomposition on the vibration acceleration signal by adopting a finite impulse response filter bank to obtain 3.2J-1 wavelet subspaces; and testing the response function of each subspace through the unit pulse function, and reordering each wavelet subspace by calculating the frequency spectrum energy center of gravity of the response function. On each scale, a transition subspace is constructed by adding non-endpoint adjacent subspaces, so that a new ternary binary fractal wavelet frequency-scale division grid is realized. In order to carry out self-adaptive quantitative identification on potential periodic impact fault characteristics in each subspace, a periodic sparsity evaluation index is provided and is used for calculating the specific gravity of characteristic frequency multiplication energy in the signal envelope demodulation amplitude spectrum of each subspace in the total energy of the signal. And the type and the position of the fault can be determined according to the characteristic frequency corresponding to the maximum value of the periodic sparse characteristic index.

The invention discloses a three-dimensional power-frequency electric-field calculating method of ground below a UHVAC power transmission line in a complex terrain. The method comprises the following steps of firstly, simplifying the complex terrain into the three-dimensional ground in a fluctuation form and establishing a calculating model; secondly, selecting a mirror image ground and assuming that the mirror image ground is extended into fluctuation ground; then, for line charges of a charged conductor discrete component segment, setting discrete point charges as a regular hexagon honeycomb form in non-mirror-image ground, and simultaneously setting corresponding mirror image charges based on a mirror image principle and establishing a discrete equation of a three-dimensional electric-field integral mathematical model; selecting a primary function as domain impulse function, selecting weight function according to a point collocation method and calculating an inner product in each domain of integration to form a matrix equation; and then, solving the matrix equation and using the calculated charges to calculate a maximum error of a matching point till that a requirement is satisfied; finally, using the optimal discrete charge to calculate three-dimensional power-frequency electric-field distribution of the fluctuation ground. By using the calculating method in the invention, calculating difficulty is reduced, calculating efficiency is increased and an actual engineering need can be well satisfied.

The invention belongs to the technical field of an optical communication technology, and particularly relates to a method for synchronizing visible light communication system frames based on an OFDM. According to the method, a training sequence structure is constructed first, and then the training sequence structure is used for detecting a frame starting position. The method comprises the steps that a training sequence is used for designing a frame synchronizing detecting function, and the frame synchronizing detecting function is made to generate a peak like an impulse function at a specified position of the training sequence; a reasonable threshold value is set to find the peak of the curve of the frame synchronizing detecting function, and therefore the frame starting position is determined. The method for synchronizing the visible light communication system frames based on the OFDM can well overcome the defects of an SC algorithm and a Park algorithm, and has high estimation accuracy.

Embodiments of the invention disclose an underwater visible light communication method and system. The method comprises the following steps of obtaining an impulse response function of an underwater channel used for transmitting a signal; sampling the impulse response function to obtain a channel characteristic matrix; modulating a to-be-transmitted signal to a plurality of subcarriers through inverse fast Fourier transform (IFFT) and splitting each modulated subcarrier into a plurality of signal blocks; determining zero fill quantity according to sampling quantity of the impulse function and carrying out zero fill processing on the end of each signal block according to the zero fill quantity; making the signal blocks subjected to zero fill processing form serial data and sending the serial data to a light signal source to generate a visible light signal; generating an electric signal according to the visible light signal and carrying out zero-forcing equalization processing on the serial signal according to the channel characteristic matrix; and carrying out fast Fourier transform (FFT) on the signal subjected to the zero-forcing equalization and restoring the to-be-transmitted signal. The method and the system can both consider the communication efficiency and quality and have wide application prospect.

The invention discloses a double-core FBG (fiber bragg grating) array sensing network. The output end of a scanning laser is connected with a semiconductor amplifier, and the output end of the semiconductor amplifier is connected with an optical circulator. An optical connector is connected with the optical circulator, and the optical circulator is connected a first FBG array and a second FBG array in a double-core FBG array. The optical circulator is connected with the input end of a photoelectric detector, and the output end of the photoelectric detector is connected with a grid wavelength detection electric signal input end of a demodulator. A semiconductor light amplification drive signal output end of a pulse function generator is connected with a drive signal input end of the photoelectric detector. A demodulation control signal output end of the pulse function generator is connected with the demodulation control signal input end of the demodulator. A pulse function generator drive signal output end of the demodulator is connected with a drive signal input end of the pulse function generator. The network is high in stability, is low in loss, and has no temperature interference.

The invention discloses an antifriction bearing surface damage fault dynamics modeling method, comprising the following steps: 1) on the basis of obtaining antifriction bearing contact equivalent stiffness and equivalent damping, considering antifriction bearing clearance and variation of a supporting region, establishing an antifriction bearing spring damping vibration model; 2) respectively loading impulse functions of surface damage fault points on an outer ring, an inner ring, and a rolling element, respectively establishing an antifriction bearing outer ring fault model, an antifriction bearing inner ring fault model, and an antifriction bearing rolling element fault model. The impulse functions of the surface damage fault points are respectively loaded on the outer ring, the inner ring, and the rolling element, and the antifriction bearing outer ring fault model, the antifriction bearing inner ring fault model, and the antifriction bearing rolling element fault model are established, the models meet actual conditions better, and calculated results are more accurate.

The invention discloses a method and apparatus for determining a sound source distance. The method comprises: a voice signal of a user is received; a spectrum feature of the voice signal is extracted; the spectrum feature is inputted into a pre-constructed voice separation model to obtain a reverberation impulse function coefficient feature; the spectrum feature is inputted into a pre-constructed voice environment analysis model to obtain voice environment information of the voice signal; and on the basis of the reverberation impulse function coefficient feature, the voice environment information, and a pre-constructed sound source distance determination model, information of a distance between a user voice and a microphone is obtained. Therefore, the accuracy of the distance measurement can be improved without a third-party sensor.

At sending end, training symbols are inserted into every other section of digital modulated communication signals and then the signals are sent. The training symbols are composed of special impulse function sequence in frequency domain. At receiving end, FFT transforms received training symbols to frequency domain. In frequency domain, after training symbols are multiplied by conjugate symbols of the training symbols, result is divided into multiple sections with identical length, then corresponding weight factors are assigned to each section, and multiple sections are superimposed as one section. Chirp-Z transform and interpolation operation are carried out for the data in the one section so as to obtain position of maximum amplitude. Frequency shift is evaluated from formula fe=fs(omega-K / 2) based on position of maximum amplitude. fe controls oscillation frequency of oscillator to reach frequency synchronism.

The invention discloses a digital image analysis method for obtaining object deformation quantity. The digital image analysis method for obtaining the object deformation quantity includes steps: S1, obtaining object images before and after deformation; S2, respectively selecting analysis areas of the same coordinate from the same portion of the same object in two images; S3, respectively performing fast Fourier transformation and mathematical treatment on gray values of pixel dots in the two analysis areas so as to obtain functions related to the gray values and the deformation quantity of the pixel dots in the two analysis areas and related to a variable in the mathematical treatment; S4, respectively calculating four different functions obtained when four different fixed values are respectively assigned to the variable in the mathematical treatment; S5, performing the mathematical treatment on the four different functions obtained in the step S4 so as to obtain a fifth function; S6, performing the Fourier transformation on the fifth function so as to obtain an impulse function including the object deformation quantity, and performing calculation so as to obtain the position of the highest impulse point in the impulse function, wherein the coordinate of the position of the highest impulse point in the impulse function is the deformation quantity caused by object deformation in the X axis direction and the Y axis direction.

The invention relates to a continuous phase modulation achieving method, in particular to a continuous phase modulation achieving method based on pulse function weighing. The continuous phase modulation achieving method includes the steps that system numbers, correlation lengths and modulation indexes of continuous phase modulation signals are selected, and rectangular pulse signals and cosine pulse signals are generated by a rectangular pulse generator and a cosine pulse generator respectively; two optimal weighing coefficients are selected according to the evaluation criterion of validity and reliability, and the weighed rectangular pulse signals and the weighed cosine pulse signals are obtained; modulation signals are obtained through the weighed rectangular pulse signals and a new pulse signal obtained through an adder. According to the continuous phase modulation achieving method, the overall good effect of the two indexes of the validity and the reliability of a digital communication system can be obtained, the increasing demands in the aspects of the error rate, the band utilization rate and the power efficiency of engineering can be met, and the continuous phase modulation achieving method is particularly suitable for wireless channels which are limited in power and bandwidth.

The invention provides a method for estimating clock frequency offset with fraction fourier domain in an ultra-wideband system, relates to a fraction-domain-aided method for estimating ultra-wideband system clock frequency offset, which solves the problems of large network cost and complex algorithm structure brought by frequency offset estimation in a network layer. After an ultra-wideband pulse waveform is coded, the ultra-wideband pulse information c(t) is modulated, a chip signal is delayed by T1 relative to the frame head of each frame of an ultra-wideband signal s1(t), the delayed chip signal is s2(t); the s1(t) and the s2(t) are added to get an emitting signal s(t); a p-order fraction fourier transform signal fp(u) is obtained from a received signal r(t); the peak position U1 of a fraction impulse function is outputted; the central position t0 of the corresponding time domain chip signal is obtained, the dimension of the t0 is removed, the t0 is normalized to obtain the central position t0' of a time domain real chip signal, a time domain ultra-wideband pulse signal r'(t) is obtained, and the position To of the frame head of the r'(t) is determined; the time lap T2 between the time domain central position t0'of the chip signal and the position To of the frame head is determined; and the clock relative frequency offset estimation of a transceiver is obtained according to the frame head delay T1.

The invention discloses a botanical pesticide, which consists of matrine, stemonine, nicotine, veratramine, osthole, chamaejasmine, root stem and leaf of hairypetal millettia, fulvic acid, an additive and a preservative. The botanical pesticide can paralyze feelers of pests to ensure that the feelers lose the function so as not to forage and mate, can also stimulate the skin of the pests at the same time to make sensory nerve of skin mucosa show an excitatory state to produce pruritus and burning heat sensation further to anaesthetize the pests so that the pests lose consciousness, and for the activity of neuromuscular junctions and nerve compound potential, stop the conduction of the excitement on nerve endings first, and can also make a nerve stem completely lose excitement and conduction impulse functions to die to ensure that the pests are also in a paralysis state even if the pests are not dead, lose the ability of damaging crops, and are nontoxic to human bodies at the same time.

The invention discloses a ground penetrating radar signal quantitative analysis method and system. The method comprises steps: ground penetrating radar signals are acquired; the ground penetrating radar signals are filtered to determine a detected target in a radar image; the detected target is extracted to obtain multiple single channel signals containing detected target reflected wave information; according to the used ground penetrating radar antenna pulse function type, a corresponding quantitative analysis-used optimal wavelet basis is selected or constructed; the optimal wavelet basis isadopted to process each single channel signal to obtain multiple detail coefficient component time-modulus curves; a wavelet singularity analysis method is adopted to determine multiple detected target reflected waves in each detail coefficient component time-modulus curve; a wavelet modulus maximum method and the multiple detected target reflected waves are used to determine the coordinates of alocal modulus maximum point; and a two-way travel time formula and the coordinates of the local modulus maximum point are used to calculate the distance between different detected target reflected waves. By adopting the method or the system disclosed in the invention, accurate quantitative analysis on the ground penetrating radar signals can be realized.

A method is provided for defining a pulse function shape for acting on a data stream for transmission in a telecommunication system which compensates for distortion by a component of the transmitter. The method comprises defining desired cost parameters (e.g., error functions for amplitude, BER, bandwidth, energy, AFC) and defining the shape of the pulse function in dependence of the desired cost parameters and the distortion to be compensated for. A pulse generator, modulator and communications device providing such a pulse function are also provided. Application in dual mode TDMA / CDMA system.

The invention discloses a method for determining displacement amount and direction of an object based on digital image diffraction, belonging to the engineering measurement field. By taking two imagesof the same object before and after deformation at the same position, and analyzing areas which have the same shape and the same number of pixels, Fast Fourier transform, variables multiplication, addition, conjugate multiplication, the variable value changing are performed to obtain four trigonometric functions about the pre-distortion image and the displacement trigonometric function, the sinetrigonometric function and the cosine trigonometric function are obtained, Discrete Fourier transform (DFT) is carried out, the result of cosine trigonometric function transform is added to the product of sine trigonometric function transform result and imaginary number j to obtain the pulse function with only one peak value. According to the position coordinates of the point corresponding to thehighest pulse value of the pulse function, the direction of image deformation and displacement can be determined directly. The invention is simple in operation, quick and intuitive.