41 results about "Frequency spectrum" patented technology

An S/P converting section (101) converts input transmission signals A1, A2, B1, B2, . . . , K1, K2 to parallelized data, separated in individual transmission lines. Spreading sections (102, 103) spread the respective data under control of a spread control section (107). Adding sections (104-1, 104-2) multiplex spread data. Transmitting sections (105-1, 105-2) provide radio transmission processing to the multiplexed signals, and transmit the data via antennas (106-1, 106-2) by radio. The spread control section (107) controls the spreading methods in the spreading sections (102, 103) based on channel quality. This makes it possible to improve error rate characteristics of the received signal and as maintain spectrum efficiency when varying data is transmitted from multiple antennas.

The invention discloses a method and device for controlling uplink power. The method comprises the steps of: calculating downlink path loss of a mobile station in a service cell; calculating path loss of the mobile station to an adjacent cell; calculating path compensating transmitting power of the mobile station according to the downlink path loss of the mobile station in the service cell and the path loss of the mobile station to the adjacent cell; and obtaining basic open loop transmitting power of the mobile station according to the path compensating transmitting power of the mobile station. According to the technical scheme provided by the invention, the system frequency spectrum efficiency and the cell edge user frequency spectrum efficiency can be simply and effectively combined.

Computer-implemented systems and methods for visually presenting spectrum usage of optical spectrum in an optical network include displaying a network map of the optical network comprising a plurality of nodes and a plurality of links connecting the plurality of nodes to one another; responsive to obtaining spectrum data comprising channel assignments on the plurality of links and nodes as endpoints of the associated channel assignments, displaying a plurality of circular histograms to visually illustrate spectrum usage in the optical network; and adjusting the plurality of circular histograms based on selections of a plurality of endpoints in the optical network. The plurality of circular histograms visually represent the spectrum usage by representing the optical spectrum in the optical network around the associated circular histogram, and wherein each portion or segment of the plurality of circular histograms represents one of a wavelength and a portion of spectrum.

A method for removing truncation artifacts in magnetic resonance images based on missing data reconstruction belongs to the technical field of image processing and comprises the following steps: detecting the magnetic resonance images with the truncation artifacts to obtain low frequency K data; carrying out Fourier inversion on the low frequency K data in the frequency encoding direction to obtain a truncated spectrum G (kx, y) of one-dimensional Fourier transform in the phase encoding direction; extracting singularities and singular value in the images of each row of data of G (kx, y) and reconstructing each row of data to obtain the high frequency partial K data; and carrying out Fourier inversion on the high frequency partial K data Fy(k) to obtain the row information fy(x) of the magnetic resonance images with the artifacts removed and storing and combining fy(x) based on rows to form the magnetic resonance images g(x, y) with the artifacts removed. The method overcomes the artifact problem existing during imaging by zero padding, ensures high signal to noise ratio of the images, effectively reduces the image errors, precisely displays the original magnetic resonance images, provides high quality reliable image information for medical nuclear magnetic resonance detection and is conductive to development and popularization of medical imaging detection technology.

The invention discloses a microphone array-oriented channel attention weighted speech enhancement method. The method comprises the following steps: respectively acquiring a path of noisy speech time domain signal from each microphone in a microphone array; constructing a multi-channel speech enhancement model; taking a short-time Fourier transform spectrum of each path of noisy speech of the microphone array as an input feature of a multi-channel speech enhancement model, and pre-training the multi-channel speech enhancement model; and inputting multiple paths of noisy speech acquired by the microphone array into the multi-channel speech enhancement model, and realizing microphone array speech enhancement by using the multi-channel speech enhancement model. According to the method, a UNETnetwork is adopted to process the voice frequency spectrum features, the parameter quantity is small, the calculation complexity is low, attention mechanism weighting operation is adopted for the channel dimension on the basis, attention weighting is carried out on each layer of encoder and decoder in the channel dimension, the features are weighted in deep structure simulation beam forming, and the performance of speech enhancement is improved.

The invention discloses a system information sending and receiving method and device in a digital audio broadcasting system. The method comprises the following steps of: when in sending, performing CRC (cyclic redundancy check) coding and channel coding on the system information to generate a coding bit stream; performing bit interleaving and constellation mapping on the coding bit stream to obtain a continuous pilot frequency including the system information; multiplexing a continuous pilot frequency signal with other signal elements of the system to obtain a frequency-domain signal of an orthogonal multiplexing structure according to a carrier allocation method stipulated by a frequency spectrum mode; converting the frequency-domain signal into a time-domain signal for sending; when in receiving, converting the time-domain signal into a frequency-domain signal; extracting the continuous pilot frequency including the system information from an effective carrier of the frequency-domain signal according to the position stipulated by the frequency spectrum mode; obtaining an estimated value of the system information through de-mapping, de-interleaving and channel decoding; and judging the correctness of the system information by use of CRC decoding, and outputting the system information. The method and device disclosed by the invention can improve the transmission robustness on the basis of guaranteeing the transmission efficiency of the system information.

The invention discloses a well-ground seismic data joint acquisition system based on distributed optical fiber acoustic wave sensing and a well drive data processing method. In order to solve the problems of inconsistent energy, inconsistent frequency spectrum and incompletely consistent coupling between a seismic source and the ground caused by repeated excitation of each seismic source point when seismic data in a well and seismic data on the ground are respectively acquired in the prior art, the invention discloses an in-well-ground seismic data combined three-dimensional acquisition systemformed by a distributed optical fiber sound wave sensing seismic data acquisition unit and a ground seismic data acquisition unit. In-well-ground combined three-dimensional exploration is carried out, ground and in-well seismic data are synchronously collected, the high-density, high-benefit, high-resolution and low-cost well-ground combined three-dimensional seismic exploration technology is achieved, and oil and gas resource exploration and comprehensive evaluation are carried out.

A method for radio resource allocation based on planned priority ordering to realize the maximum carrier to interference ratio (C/I) in a cellular system that employs frequency reuse. Reuse of co-channel resources is progressively increased as traffic load increases based on the available spectrum. By using this method, interference rejection at light loading can approach that obtainable by using a low reuse factor. When applied to a wireless packet network, this method allows each resource to carry highest throughput according to the traffic demand and available bandwidth, while making more resources available to carry additional traffic when system loading is increased.

The invention discloses a method for detecting a type of a medium material of a part for receiving terminal equipment. The method comprises the following steps of A, by an acceleration sensor built in terminal equipment, acquiring a sampling value of an accelerated speed produced by terminal equipment vibration, carrying out spectral analysis of the sampling value of the accelerated speed, and determining hardness of a medium material of a part for receiving the terminal equipment according to the analysis result, and B, through a sound sensor built in the terminal equipment, carrying out sound spectrogram analysis, and distinguishing the medium materials having similar hardness according to the analysis result. The method can realize spectral analysis of the accelerated speed sampling value and the voice frequency sampling value only by the terminal equipment, can accurately determine the type of a medium material of the part for receiving the terminal equipment, adopts a simple calculation method, produces an accurate determination result, and has a strong practical meaning and a popularization value.

The invention provides a mobile video monitoring system based on cognitive radio. The mobile video monitoring system comprises a control center and a mobile terminal. The control center is wirelessly communicated with the mobile terminal through an ISM frequency band. The control center is used for monitoring communication quality and determining whether spectrum sensing and channel switching need to be carried out or not according to the communication quality. If data transmission between the mobile terminal and the control center cannot be recovered through the channel switching, the data transmission of the mobile terminal is relayed through a relay robot. The invention further provides a mobile video monitoring method. According to the mobile video monitoring system and the method, the unfixed communication frequency band is adopted, and in the ISM frequency band, channel interference is automatically sensed and avoided, and the interference problem is solved. The wireless signal fading problem is solved through power control and relay transferring, and therefore the real-time performance and reliability of video transmission are guaranteed. The mobile video monitoring system and the method do not depend on the coverage of the commercial wireless network, and have actual application significance in video monitoring in the emergency environment, the severe environment and the unknown environment.

The invention provides an uplink system of a subcarrier multiplexing optical network of filter based multicarrier modulation. The system comprises access control modules, filter based multicarrier modulation modules, subcarrier modulation modules, a multiplexing module, a feed line type fiber, a de-multiplexing module, photoelectric detectors, subcarrier demodulation modules and uplink data reception modules that are successively connected. Data generated by the access control modules is modulated in the filter based multicarrier modulation method, modulated user data is modulated to different optical subcarriers and transmitted via RF subcarrier modulation of optical carrier waves, and data from different units is multiplexed to uplink fiber channels. Filter based multicarrier modulation technology is combined with subcarrier multiplexing technology so that frequency spectrum resources of uplinks are utilized in high efficiency, interference among symbols and subcarriers of uplink users can be effectively resisted, and higher transmission speed and frequency spectrum frequency can be supported.

The invention discloses a method for accessing and exiting frequency spectrum of a hybrid cognitive network by adopting the conventional wireless communication technology. Wireless communication adopts a multi-band mode and comprises an authorization network and a cognitive network; a special node is included in a cognitive user; centralized frequency spectrum perception and channel allocation and management are performed by using a public control channel and the special node when the cognitive user is accessed; and the method for exiting of the cognitive user adopts a distributed mode after a channel is re-occupied by the authorization network. By adopting centralized access allocation, distributed perception exiting, and a point-to-point communication method, and the functions of accessing and exiting are separated to ensure the cognitive working efficiency and the complexity of a cognitive network system. Moreover, each node shares same hardware resources, so the special node can be arbitrarily selected or replaced, and the comprehensive reliability of the system can be also improved.

The invention discloses a KS-CSS modulation method, and belongs to the technical field of the spread spectrum communication. In consideration of the problem that a transmission rate of the existing modulation mechanism is limited and the spectrum utilization rate is low, the two-dimensional data information is imported in the premise of unchanging the one-dimension data spread-spectrum mechanism and the transmitting power from the composite dimension angle, the spread-spectrum pseudo code is selected through a data mapping mechanism, and the two-dimension data information transmission is realized at the same time; the modulation order k is flexibly configured by using the transmission relation of the one-dimension and the two-dimension, thereby establishing the K-order composite spread-spectrum modulation mechanism. Through the method disclosed by the invention, the spread-spectrum pseudo code is dynamically updated through a two-dimension data mapping mechanism, the confidentiality ofthe one-dimension data is improved, and the two-dimension data information transmission is performed without importing additional power and occupying the extra frequency band condition. Through the method disclosed by the invention, the data transmission rate and the frequency band use ratio are improved, the aim of hiding the communication can be achieved, and the method can be applied to all spread-spectrum communication systems.

The utility model discloses a mathematical model testing tool, and relates to the technical field of mathematical model simulation testing. The mathematical model testing tool comprises a sensitivityanalysis module which is used for analyzing and judging the effectiveness of a model by investigating the influence condition of the change of a group of sensitivity coefficients in the mathematical model on the output of the mathematical model; a frequency spectrum analysis module which is used for analyzing the statistical characteristics in the frequency domain of the mathematical model by adopting a stationary random process algorithm and a generalized stationary random process algorithm; and an uncertainty analysis module which is used for evaluating the influence degree of the uncertainty of the simulation input parameters on the system output so as to judge whether the failure caused by the input uncertainty occurs or not and calculate the failure probability. A mathematical model checking tool is provided, so that the establishment and management of model data are realized; and through sensitivity analysis, spectrum analysis and uncertainty analysis, based on statistical inference of spectrum analysis, verifying and confirming the simulation mathematical model of the complex system layer by layer, thereby forming a verified and confirmed high-precision model.

The invention discloses a continuously variable-rigidity chaos vibration isolation device. The device is characterized in that: the continuously variable-rigidity chaos vibration isolation device comprises a first vibration isolator and a second vibration isolator; one end face of the first vibration isolator and one end face of the second vibration isolator are oppositely arranged; a spacing distance for containing a vibration isolated device is arranged between the first vibration isolator and the second vibration isolator; both the first vibration isolator and the second vibration isolator are contacted with the vibration isolated device; the other end face of the first vibration isolator is provided with a contact surface connected with a base body, and a separated area is arranged between the contact surface and the base body; and the other end face of the second vibration isolator is provided with a contact surface connected with the base body, and a separated area is arranged between the contact surface and the base body. The invention has the advantages that the device can enter into chaos under the small displacement vibration condition, has excellent vibration isolation effect and changes line spectrum into wide spectrum.

The invention discloses an SRM torque ripple suppression control system and method based on a Fourier neural network, and the method comprises the steps:a Fourier neural network frequency spectrum detection module is built according to the relation between a torque and an actual output torque, and a frequency spectrum containing the content of each harmonic in an output torque signal of the Fourier neural network is rapidly obtained online; dynamic characteristics of torque are considered in a combined mode, a signal generator for reference torque compensation is designed according to torque harmonic information and historical torque harmonic information which are obtained online, output of the signal generator compensates reference torque output by a speed controller, harmonic information corresponding to undesired output torque ripple caused by the reference torque is eliminated, and more ideal reference torque is obtained; and under the cooperation of the torque distributor and the current inner loop control, the amplitude of each harmonic of the output torque of the control system is greatly reduced, and the torque ripple is effectively restrained.

The invention provides a resistance-double resonance composite sound absorbing profile. The resistance-double resonance composite sound absorbing profile comprises a resistance sound absorbing material, an aluminum fiberboard, a micro-perforated panel and a plate surface support frame which are independent from one another. According to the technical scheme provided by the invention, different noise frequency bands are inhibited for different noise source frequency spectrum features by adjusting material parameters and the process parameters of a cavity structure; and a low-frequency sound absorbing coefficient to 125 Hz can reach 0.54. An average sound absorption coefficient to a frequency band of 125 Hz-500 Hz can reach 0.77, and the minimum sound absorption coefficient to a frequency band of 250 Hz and 1,600 Hz can reach 0.36.

The invention particularly relates to an inter-channel phase difference and amplitude difference high-precision measurement method comprising the following steps that (A) supposing that multichannel input signals are r(k); (B) digital down-conversion processing is performed on each channel and the IQ data r<ddc>(k) after down-conversion are obtained by the decimation filter; (C) any one channel r(m) is selected to act as the reference channel and conjugating of r<ddc>(m) is performed so as to obtain r<*><ddc>(m); (D) the down-conversion data of other channels and the down-conversion conjugatedata of the reference channel are multiplied so as to obtain the processed complex signal r<mul>(k)=r<ddc>(k).r<*><ddc>(m); and (F) the phase difference phi<delta>(k) and the amplitude difference A<deltah>(k) between the kth channel and the mth channel are calculated according to the obtained complex signal: mean filtering is performed on the DC component after conjugate multiplying and there is no spectrum leakage so that the calculation precision is higher than that of conventional FFT; and mean filtering is realized by using the first-order CIC filter so that the calculation amount is muchlower in comparison with that of the conventional FFT method and the advantage is more obvious especially in case of high number of channels.

The invention discloses a spectrum defragmentation trigger method based on spectrum sensing in an elastic optical network. The spectrum defragmentation trigger method comprises the following steps that step (1): the spectrum availability before defragmentation and the business demand degree are calculated; step (2): the spectrum availability before defragmentation and the business demand degree are compared, and spectrum defragmentation is not required when the spectrum availability before defragmentation is greater than or equal to the business demand degree; and the spectrum availability after defragmentation is calculated when the spectrum availability before defragmentation is less than the business demand degree, and the step (3) is performed; and step (3): the spectrum availability after defragmentation is compared with the business demand degree, and the spectrum defragmentation mechanism is triggered when the spectrum availability after defragmentation is greater than or equalto the business demand degree; and spectrum defragmentation is not required when the spectrum availability after defragmentation is less than the business demand degree. The spectrum defragmentation trigger method has the advantages of increasing the success rate of network business transmission, reducing network business blocking rate and enhancing the network resource utilization efficiency.

The invention discloses a QPSK-DS communication detecting method based on delay multiplication. A system is initialized and begins to scan a target frequency band to amplify signals entering the system from the radio frequency front end, radio frequency signals are converted into fixed middle frequency to be amplified through a difference frequency method, digital signals can be achieved through analog-digital conversion, delay multiplication operation is carried out, digital lowpass filtering is carried out to obtain lowpass signals, and a frequency spectrum of the lowpass signals can be achieved through an FFT algorithm. The QPSK-DS communication detecting method has the advantages of adopting a linear and non-linear processing method to achieve full detection on QPSK-DS communication through simple comprehensive analysis and processing on time frequency domains and being simple to achieve, strong in operability and strong in capacity adapting to low signal to noise ratio. Meanwhile, the method adopts the middle frequency analysis instead of radio frequency or baseband processing to avoid high requirements for performance of processing capacity of a receiver as possible. Furthermore, the method can achieve real-time processing easily and is strong in practicability.

The invention discloses a method for coding a layered space-time code and a system thereof. The method comprises the following steps of: coding all the 2transmitting antennas of the transmitting end of a multiple input multiple output (MIMO) system; ensuring the number 2of the transmitting antennas of the transmitting end practical for transmitting a symbol, wherein, n is equal or greater than 0 and less than N; reading 2bit group with (N-n+m) length in a bit sequence which is to be transmitted, and coding the bit group; coding the bit group code and jointly forming into a binary sequence A with the (N-n) bit in the bit group, mapping the other m bit in the bit group into a symbol sj by M=2level modulation, and mapping the symbol sj to the transmitting antenna which is coded to be A; and judging whether the nt=2bit group has been mapped, if not, continuously executing the last step, otherwise, transmitting the symbol by 2 antennas which are mapped with the symbol by the transmitting end. Under the premise that spectrum effectiveness is invariable, the invention effectively improves the diversity order of the MIMO system so as to improve testing performance and reduce testing complexity.

The invention discloses a fault detection system and method for eliminating periodic disturbance based on complex coefficient gain, and relates to the technical field of fault detection. By optimizing the disturbance transfer function matrix and configuring the corresponding complex coefficient gain vector at the disturbance frequency point, the output signal of the detected system is filtered twice, so that the output response of the disturbance signal of the specific frequency spectrum in the residual signal is remarkably reduced, and the detection effect on small faults is greatly improved; compared with a traditional fault detection method based on an observer, tiny faults can be found and detected earlier, equipment can be stopped in time, and corresponding monitored equipment can be protected.

A shear wave velocity is accurately measured. Time change data of a displacement of a tissue due to a shear wave generated in a test object is calculated from a reception signal obtained by transmitting an ultrasonic wave to the test object and receiving a reflected wave. The time change data of the displacement is converted into spectrum data indicating a displacement distribution in a frequency space having a spatial frequency and a time frequency as two axes. Spectrum data in a predetermined region is extracted by rotating the spectrum data by a predetermined angle in the frequency space, and filtering the rotated spectrum data. A velocity of the shear wave is calculated based on the extracted spectrum data in the predetermined region.