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45 results about "Joint frequency" patented technology
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Apparatus and method of multiple antenna receiver combining of high data rate wideband packetized wireless communication signals
InactiveUS20050078649A1Limited diveristy gainIncrease diversity gainSpatial transmit diversityPolarisation/directional diversityDigital dataFast Fourier transform
The present invention provides an apparatus and method of multiple antenna receiver combining of high data rate wideband packetized wireless communication signals, where the apparatus includes M receive antennas, receiving M high data rate wideband packetized wireless communication signals, where each of the signals includes N frequency bins. The apparatus, in an exemplary embodiment, includes (1) a joint timing recovery units that perform joint coarse signal timing estimation, joint frequency offset estimation, and joint fine timing estimation on each of the signals, (2) M Fast Fourier Transform units (FFTs) that each convert the digital data for each of the M signals into frequency domain information for each of the N received frequencies and that output Q pilots for each of the signals, where Q is a positive integer, and (3) a combiner that weights and combines the outputs of the M FFTs for each of the N received frequencies.
Owner:QUALCOMM INC
Apparatus and method of multiple antenna receiver combining of high data rate wideband packetized wireless communication signals
InactiveUS7366089B2Eliminate the effects ofMitigation of impairmentSpatial transmit diversityPolarisation/directional diversityDigital dataFast Fourier transform
The present invention provides an apparatus and method of multiple antenna receiver combining of high data rate wideband packetized wireless communication signals, where the apparatus includes M receive antennas, receiving M high data rate wideband packetized wireless communication signals, where each of the signals includes N frequency bins. The apparatus, in an exemplary embodiment, includes (1) a joint timing recovery units that perform joint coarse signal timing estimation, joint frequency offset estimation, and joint fine timing estimation on each of the signals, (2) M Fast Fourier Transform units (FFTs) that each convert the digital data for each of the M signals into frequency domain information for each of the N received frequencies and that output Q pilots for each of the signals, where Q is a positive integer, and (3) a combiner that weights and combines the outputs of the M FFTs for each of the N received frequencies.
Owner:QUALCOMM INC
Method and system for pushing information
ActiveCN103327110AControl exposure frequencyAvoid situations where the experience suffersTransmissionObjective informationResource information
The invention discloses a method and system for pushing information. The method comprises the steps of obtaining the user information and the operation information of a target network terminal, confirming target information pushed to the target network terminal according to the operation information of the target network terminal, obtaining the push control information of the target information, obtaining the push record of the target information and the push record of associated information according to the push resource information of the target information and the push resource information of the associated information respectively, and controlling the target information to be pushed to the target network terminal according to joint frequency control information, the push record of the target information and the push record of the associated information of the target information. Due to the adoption of the method, joint frequency control can be carried out on the target information and the associated information of the target information according to the needs of a user, and the fact that the exposure frequency of relatively associated push information is controlled more accurately and more flexibly is achieved.
Owner:TENCENT TECH (SHENZHEN) CO LTD
Systems and methods for echo cancellation and echo suppression
InactiveUS8634569B2Two-way loud-speaking telephone systemsEcho suppressors/cancellersTime domainEngineering
Traditionally, echo cancellation has employed linear adaptive filters to cancel echoes in a two way communication system. The rate of adaptation is often dynamic and varies over time. Disclosed are novel rates of adaptation that perform well in the presence of background noise, during double talk and with echo path changes. Additionally, the echo or residual echo can further be suppressed with non-linear processing performed using joint frequency-time domain processing.
Owner:SYNAPTICS INC
Offset modulation orthogonal frequency division multiplexing (OFDM) and multi-access transmission method with cyclic prefix (CP)
ActiveUS20130148488A1Reduce signal envelope fluctuationMaintaining spectral efficiencyMultiple-port networksDelay line applicationsFrequency spectrumSymmetric extension
The present invention provides an Offset Modulation Orthogonal Frequency Division Multiplexing (OFDM) and multi-access transmission method with a Cyclic Prefix (CP), including a generating method of the sent signal in the sending terminal and a processing method of the received signal in the receiving terminal, the method includes: in the sending terminal, performing generalized discrete Fourier Transform on real-value digital baseband modulated symbols and obtaining the frequency-domain signal; performing conjugate symmetric extension, frequency-domain filtering, sub-carrier mapping on the frequency-domain signal; performing Inverse Fast Fourier Transform on the frequency-domain signal after sub-carrier mapping; inserting a CP and obtaining the time-domain sent signal; in the receiving terminal, including: removing the CP, performing Fast Fourier Transform on CP removed symbols and obtaining the frequency-domain received signal; and based on multiple user joint frequency-domain equalization performing iterative detection decoding on the frequency-domain received signal. The present invention can obtain the low-signal envelope volatility in the condition of remaining spectrum efficiency, and adopting iterative received signal processing method based on multiple user joint frequency-domain equalization ensures the transmission reliability with low-complexity.
Owner:HUAWEI TECH CO LTD
Multi-region cooperative joint frequency modulation control method based on dual-layer model predictive structure
PendingCN108964087AEnsure safetyReduce joint FM costsSingle network parallel feeding arrangementsPower oscillations reduction/preventionEconomic model predictive controlEngineering
The invention provides a multi-region cooperative joint frequency modulation control method based on a dual-layer model predictive structure. The method realizes the steady-state power optimized application of cross-regional AGC units under the multi-constraint condition on the basis of the economic model predictive control in the upper layer; and the dynamic frequency optimization control of themulti-region AGC units on the basis of the distributed model predictive control is realized in the lower layer. On the slow time scale (minutes), the steady-state power optimized allocation of the cross-regional AGC units considering the safety constraints of tie line sections is realized. On the short time scale (seconds), the dynamic frequency optimization control of the AGC units in each regionis realized.
Owner:WIND POWER TECH CENT OF GANSU ELECTRIC POWER +2
Radar orthogonal waveform design method based on frequency modulation and phase modulation of chaotic sequence
InactiveCN105116384APower Spectrum FlatSharp autocorrelation functionWave based measurement systemsSelf-phase modulationVIT signals
The invention discloses a radar orthogonal waveform design method based on frequency modulation and phase modulation of a chaotic sequence, comprising the following steps: S1, using a chaotic system to generate a chaotic sequence of which the length is N*P, and cutting the chaotic sequence into P sequence sections (the length of each sequence section is N), selecting one sequence section, and letting the sequence section be {x(0), x(1), x(2),...,x(N)}; S2, encoding a chaotic joint frequency modulation and phase modulation signal, dividing a pulse into a series of equal sub pulses, and carrying out frequency modulation differently on different sub pulses, and then, using the sequence section obtained in S1 to carry out phase encoding on each cycle of a waveform in each frequency encoding sub pulse, and obtaining a phase-frequency joint modulation chaotic radar signal through use of a randomly-generated initial phase; and S3, calculating a complex envelope signal of the phase-frequency joint modulation chaotic radar signal obtained in S2. The signal frequency and phase change as a chaotic signal changes, the orthogonality of signals is improved, and the interception probability is reduced.
Owner:UNIV OF ELECTRONICS SCI & TECH OF CHINA
Method and device for maximum likelihood frequency offset estimation based on joint pilot frequency
InactiveCN103873411ALarge frequency offset estimation rangeImprove frequency offset estimation performanceMulti-frequency code systemsMulti inputSlide window
The invention discloses a method and a device for maximum likelihood frequency offset estimation based on a joint pilot frequency. The method and the device are used for reception synchronization of a multi-input multi-output (MIMO)-orthogonal frequency division multiplexing (OFDM) system. The method comprises the following steps: a receiving end preprocesses a corresponding nth transmission pilot symbol matrix D(n), a discrete Fourier transform (DFT) matrix F, and a matrix W(wavy line) composed of the first L columns of the matrix F to obtain a matrix P(n); the receiving end respectively and correspondingly stores a receiving pilot symbol matrix R(n) and the matrix P(n) in first-in-first-out sliding window memories with the length being M; and M frequency offset matrixes are constructed, the receiving pilot symbol matrix R(n) and the matrix P(n) are acquired from the sliding window memories, a likelihood function is calculated according to the receiving pilot symbol matrix R(n), the matrix P(n) and the M frequency offset matrixes, and frequency offset estimation values to be selected are substituted in the likelihood function to obtain a frequency offset estimation value, which makes the accumulation of values of the likelihood function minimum, as the final maximum likelihood frequency offset estimation value.
Owner:ZTE CORP
Direct current transmission system and generator set joint frequency modulation starting method
ActiveCN103986170AImprove economyAvoid the problem of FM needing to add a lot of spare capacityPower oscillations reduction/preventionModulation functionEngineering
The invention provides a direct current transmission system and generator set joint frequency modulation starting method. A direct current transmission system and a generator set are started according to the frequency deviation delta f of an alternating-current system to realize joint frequency modulation, wherein the starting comprises the high-frequency starting mode and the low-frequency starting mode; if the frequency deviation delta f is greater than zero, then direct current transmission system and the generator set are started in the high-frequency starting mode; and if the frequency deviation delta f is less than zero, then the direct current transmission system and the generator set are started in the low-frequency starting mode. Compared with the prior art, according to the direct current transmission system and generator set joint frequency modulation starting method provided in the invention, the primary frequency modulation capability of the generator set and the modulation function of the direct current transmission system are utilized comprehensively, the problem that a lot of spare capacity needs to be increased when frequency modulation is performed by only relying on the generator set can be avoided, and at the same time, the power changing amount of the direct current transmission system is limited through coordination frequency control, so frequent switching of the direct-current two-end alternating-current filter can be avoided, so that the economy of the direct current transmission system can be improved.
Owner:STATE GRID CORP OF CHINA +3
Transmitter-receiver joint frequency selective IQ imbalance estimation and compensation method for self-loopback structures
InactiveCN104980376AEliminate performance impactEfficient communicationTransmitter/receiver shaping networksEngineeringUp conversion
The invention discloses a transmitter-receiver joint frequency selective IQ imbalance estimation and compensation method for self-loopback structures, comprising the following steps: aiming at amplitude distortion and phase deviation of in-phase (I) and quadrature (Q) signals at a radio-frequency front end and different frequency responses of the two signals, designing two self-loopback structures to cascade an up-conversion unit and a down-conversion unit of the signals to obtain two IQ imbalance models; using a frequency domain training sequence to obtain two cascaded equation sets through the two self-loopback structures, solving the cascaded equation sets, and respectively estimating the parameters needed for compensating the frequency points of frequency selective IQ imbalance of a transmitter and a receiver; and compensating frequency selective IQ imbalance of the transmitter and the receiver in a frequency domain according to the compensating coefficients of the frequency points. The method of the invention is low in computing complexity, and can improve the system performance obviously.
Owner:ZTE WAVETONE SCI & TECH
A multi-machine parallel virtual synchronization control system and method for cascaded energy storage system
ActiveCN109245123AImprove power qualityQuick responseAc network load balancingPower oscillations reduction/preventionPower qualityLow voltage
The invention discloses a multi-machine parallel virtual synchronization control system and method for a cascade energy storage system. According to the three-phase voltage of each cascaded energy storage converter, a grid active power given command, as well as the current power of the thermal power unit, the active power is calculated and obtained; the active power and the active power change aresuperposed to obtain the total active power given value, and then the average modulation voltage and the equalization control voltage components of the power conversion unit are superposed to obtainthe total modulation voltage. finally, the pulse driving signals of each power device are calculated. The invention realizes the high-voltage direct-hanging parallel connection of multiple cascaded energy storage converters to the joint frequency modulation operation of the low-voltage side of the high-power transformer and the thermal power unit of the thermal power plant, and has the advantagesof virtual synchronous friendly operation of multiple machines in parallel, high-capacity, high-efficiency and fast response, bi-directional charge-discharge regulation, highly self-balanced control,high power quality and convenient centralized dispatching frequency modulation.
Owner:JIANGSU WEIFAN INTELLIGENT ELECTRICAL TECH
Multi-sequence joint frequency hopping communication method combined with pseudo-random feature codes
The invention relates to a multi-sequence joint frequency hopping communication method combined with pseudo-random feature codes, which is characterized in that on the basis of multi-sequence joint frequency hopping, the pseudo-random feature codes are modulated onto frequency hopping carriers in an in-band spread spectrum mode, and feature information except the carrier frequency is added to a data channel to serve as a mark for distinguishing signal sources. The receiver makes a decision by using the correlation between the known pseudo-random feature code and the transmitted signal, therebyreducing the error code caused by the occurrence of an interference signal in a multi-sequence frequency hopping dual channel. According to the invention, the anti-interference capability of multi-sequence joint frequency hopping communication is further improved.
Owner:ARMY ENG UNIV OF PLA
Random access method and system
InactiveCN101198152AGuaranteed access performanceBig timeRadio/inductive link selection arrangementsRadio transmission for post communicationRandom access memoryDistribution pattern
The invention relates to a random access method and comprises that: after a mobile station reads the downlink synchronizing information and broadcast information of a cell, a random access channel with a certain length is selected and sends an access sequence. The invention also relates to a random access system which comprises a mobile station and a base station, wherein, the mobile station is used for reading the downlink synchronizing information and broadcast information of the cell and selects the random access channel with the certain length to send the access sequence; the base station is connected with the mobile station through network and is used for sending the downlink synchronizing information and broadcast information and receiving the access sequence sent by the mobile station. Therefore, the random access method and the system of the invention achieve that the mobile station sends the access sequence through the random access channel which is selected according to the time-frequency distribution patterns of the random access channel. The invention can ensure the access performance, unites the frequency and time resource to design RACH distribution patterns and takes regular changes among various patterns into account to achieve effects of the maximal time and frequency diversity.
Owner:HUAWEI TECH CO LTD
Joint frequency and unique word detection
ActiveUS20110135048A1Amplitude-modulated carrier systemsAmplitude demodulationStart timeBurst transmission
Systems, devices, processors, and methods are described for joint detection of frequency and unique word (UW) location(s) for burst transmissions. Embodiments receive a wireless signal. Frequency detection is performed, resulting in multiple possible frequency correlation peaks. A subset of the correlation peaks are each used to perform trial frequency corrections, thereby generating a set of trial sequences. A UW correlation is performed on each of the trial sequences to generate a maximum UW correlation value for each trial sequence. The UW correlation value and the frequency correlation peak value are weighted and combined to generate a joint detection correlation value. The trial sequence having largest joint detection correlation value may indicate the correct transmission frequency and UW location. The jointly detected information may then be used to identify the frequency and start time of the burst transmission, which may then be demodulated, decoded, etc. to recover its payload data.
Owner:VIASAT INC
Joint frequency modulation control strategy for improving frequency of AC/DC grid-connected system in wind power plant
ActiveCN109659960AImprove frequency characteristicsGuaranteed safe operationPower oscillations reduction/preventionPeaking power plantEngineering
The invention discloses a joint frequency modulation control strategy for improving a frequency of an AC / DC grid-connected system in a wind power plant. The joint frequency modulation control strategyproposes a method employing energy storage and flexible DC additional control to participate in system frequency adjustment for improving main grid frequency, and comprises the steps of: firstly, adding flexible DC frequency additional control based on wind power plant frequency variation into a flexible DC converter station at the wind power plant side, and preferentially improving the frequencyproperty of the wind power plant by utilizing the features of high transmission power and capability of short-time overload operation of flexible DC power transmission; and secondly, parallelly connecting an energy storage system on a DC line between the wind power plate and a main grid by means of a current converter, and compensating for the frequency deterioration effect of the DC additional control at the wind power plant on the main grid. The joint frequency modulation control strategy preferentially improves the frequency properties of the wind power plant, ensures the safe operation ofthe wind power plant, and improves the frequency properties of the main grid.
Owner:SICHUAN UNIV
Symmetrical frame-based carrier synchronization method
ActiveCN105406956ASolve frequency offsetSolve the coupling problem of phase bias estimationError preventionCarrier regulationFrame basedIntermediate frequency
The invention discloses a symmetrical frame-based carrier synchronization method. The method comprises steps: 1, a pilot block and a data block are generated; 2, a data frame structure is set; 3, signals are sent at a sending end; 4, joint frequency phase offset estimation is carried out at a receiving end; 5, frequency phase offset correction signals are demodulated; and 6, Turbo code decoding is carried out. Defects that frequency offset estimation and phase offset estimation cannot be decoupled in the prior art, and influences on error code performance by large residual frequency offset cannot be effectively solved are overcome, and through arranging the symmetrical data frame structure, the problem of coupling the frequency offset estimation and the phase offset estimation in the case of joint frequency phase estimation can be solved, and the influences on the estimation performance by the large frequency offset can be reduced; and defects that the bit error rate for decoding is influenced as influences of phase offset cannot be cancelled in the case of frequency offset estimation are also overcome, and through carrying out Turbo code decoding on signals after demodulation of the symmetrical frames, the outputted code is obtained, and the bit error rate for decoding is reduced.
Owner:XIDIAN UNIV
Joint frequency phase estimation method based on partial decoupling
InactiveCN107911323AReduce the influence of frequency offset estimation on phase offset estimationAvoid settingCarrier regulationMulti-frequency code systemsEstimation methodsCarrier frequency offset
The invention discloses a joint frequency phase estimation method based on partial decoupling. The problem of failed subsequent phase offset estimation caused by large carrier frequency offset of traditional joint frequency phase estimation is solved. The technical scheme comprises the steps that 1 on a receiving end, any pilot signal is demodulated to acquire a demodulated signal; 2 correlation operation is carried out on the demodulated signal and a delayed signal whose sampling time interval is alpha, and the result of the correlation operation is used to acquire a frequency offset estimation value; and 3 the maximum likelihood phase offset estimation is carried out on the conjugate form of the correlation operation result taking alpha as the half of the pilot length and the demodulatedsignal jointly to acquire a phase offset estimation value. According to the invention, the anti-frequency offset ability of phase offset estimation is improved; the complexity of phase offset estimation is reduced; the sampling zero time position of the receiving end is not manually set; the feasibility in practical applications is improved; and the method can be used for space communication including satellite communication, unmanned aerial vehicle communication and spaceflight test control.
Owner:XIDIAN UNIV
Transmission and receiving method and device for fraction Fourier domain and frequency domain joint frequency spreading signals
InactiveCN101262249ASolve the shortcomings of low spectrum utilizationImprove spectrum utilizationMulti-frequency code systemsFrequency spectrumCommunications system
An emission and receiving method for frequency hopping signals combined by a fractional Fourier domain and a frequency domain as well as a device thereof are provided. The invention relates to a frequency hopping technology in wireless communications and solves the defect that the utilization ratio of frequency spectra in the traditional frequency hopping communication system is not high. Two channels of binary digital signals are obtained by a signal source at a signal sending terminal and then one channel of binary digital signals is modulated to fractional domain frequency hopping signals and the other channel is modulated to traditional carrier frequency hopping signals. Mixed frequency hopping signals are obtained by adding the two channels of signals. At a receiving terminal, firstly received signals are fractional domain de-hopped. The fractional domain frequency hopping signals are filtered from the received signals by the other demodulator circuit and then the frequency domain de-hopping is processed and demodulated to obtain frequency domain de-hopping signals. Finally the obtained fractional domain de-hopped signals and demodulated signals are changed in series / parallel so as to obtain subscriber signals. The combined frequency hopping method realizes the transmission of two-way data in the same frequency band range so as to greatly improve the system capacity of the communication system.
Owner:HARBIN INST OF TECH
Electric press plier
InactiveCN102120319AEasy crimpingReduce volumePortable power-driven toolsMetal-working hand toolsControl systemGear wheel
The invention discloses an electric press plier which comprises a shell, wherein a switch is arranged on the shell, the inside of the lower end of the shell is provided with a power supply and a circuit control device, the inside of the upper end of the shell is provide with a motor and a speed reducer, a drive gear is arranged on an output shaft of the speed reducer and mutually matched with a driven gear fixedly arranged on a screw barrel, the screw barrel is sleeved on a screw in the shell and mutually and helically matched with the screw, a knocking block is arranged on the screw, the shell is internally and respectively provided with a front stroke switch and a rear stroke switch which are mutually matched with the knocking block, a digital display device is arranged on the rear end of the shell, and the front end of the screw is mutually matched with a plier assembly arranged at the front end of the shell. The invention has the advantages of avoidance of structural defects of hydraulic compression joint, convenience for compression joint, small volume, light weight, convenience for carrying, high automation, convenience for use and management because the compression joint frequency is measured by a control system and displayed by the digital display device, and the like.
Owner:ZHANGJIAGANG CHUANGJI MACHINERY MFG
Online prediction method for power grid frequency situation based on multi-resource joint frequency modulation
InactiveCN109742774AEasy to controlConvenient command and dispatchMaterial analysis by optical meansPower oscillations reduction/preventionEngineeringFrequency modulation
Aiming at the influence of a photothermal power station on the frequency characteristics of the surrounding power grids after accessing a regional power grid, the patent proposes an online predictionmethod for a power grid frequency situation considering thermal power, photothermal and demand-side response joint frequency modulation according to a governor model of a photothermal generator. The method comprehensively considers the functions of thermal power units, photothermal units and demand-side responses in the system frequency response (SFR) process, and establishes an aggregation modelfor the joint frequency modulation of the thermal power units, the photothermal units and the demand-side responses by online collecting operation state data of power grids and equipment information of the units. The aggregation model characterizes the process that the thermal power units, the photothermal units and the demand-side responses participate in frequency modulation in the form of transfer functions. Compared with an existing method, the method adds the frequency modulation functions of the photothermal unit governor and the demand-side responses on the basis of a traditional systemfrequency response model, can perform online prediction on the power grid frequency situation, and can improve the prediction capability of the power grids to the system frequency.
Owner:STATE GRID GASU ELECTRIC POWER RES INST +3
Method and system for correcting IQ and TIADC joint frequency distortion
ActiveCN106375252AWith cyclic propertiesLimit impurity-free dynamic rangeCarrier regulationCompensation effectRadio frequency
The invention discloses a method for adaptively correcting IQ (in-phase / quadrature) and Time Interleaved Analog-to-Digital Converter (TIADC) joint frequency distortion. A very extensive instantaneous radio frequency bandwidth can be digitalized by the joint IQ and TIADC, but because of the mismatch of an analog device, a distortion component is generated in a receiver, thereby limiting a Spurious Free Dynamic Range (SFDR) of the system. Generally, a composite communication signal has circularity (circularity), while the frequency distortion of the IQ and the TIADC destroys the circularity of the signal, the joint frequency distortion of an IQ and Time Interleaved Converter (IQ-TIC) in the receiver can be corrected by the method acquired according to principles related to a convolution method without using any reference signal, and thus the compensation effect is good.
Owner:SYSU CMU SHUNDE INT JOINT RES INST +1
Joint frequency and unique word detection
ActiveUS8243859B2Amplitude-modulated carrier systemsAmplitude demodulationBurst transmissionStart time
Systems, devices, processors, and methods are described for joint detection of frequency and unique word (UW) location(s) for burst transmissions. Embodiments receive a wireless signal. Frequency detection is performed, resulting in multiple possible frequency correlation peaks. A subset of the correlation peaks are each used to perform trial frequency corrections, thereby generating a set of trial sequences. A UW correlation is performed on each of the trial sequences to generate a maximum UW correlation value for each trial sequence. The UW correlation value and the frequency correlation peak value are weighted and combined to generate a joint detection correlation value. The trial sequence having largest joint detection correlation value may indicate the correct transmission frequency and UW location. The jointly detected information may then be used to identify the frequency and start time of the burst transmission, which may then be demodulated, decoded, etc. to recover its payload data.
Owner:VIASAT INC
Joint frequency offset estimation method and system
ActiveCN112422472AHigh precisionImprove performanceSpatial transmit diversityMulti-frequency code systemsControl theoryFrequency offset
The invention provides a joint frequency offset estimation method and a joint frequency offset estimation system. The joint frequency offset estimation method comprises the following steps: S1, compensating a frequency offset estimation value using SSB or TRS; S2, after the compensated signal is subjected to intermediate processing, a channel estimation module being executed; S3, executing an MIMOdetection module on a result after channel estimation; S4, performing frequency offset attempt on a result after MIMO detection; S5, storing the signals modulated by the sending end, and taking the stored signals modulated by the sending end as entry data of a frequency offset attempt module; and S6, acquiring the MIMO detection signal after frequency offset adjustment. The SSB and TRS referencesignals are periodic reference signals, a certain error exists in frequency offset estimation, frequency offset attempt is introduced into the detection module to perform joint frequency offset estimation, and the precision of frequency offset estimation is further improved.
Owner:上海微波技术研究所(中国电子科技集团公司第五十研究所)
Reduced dimension time domain channel estimation in a wireless communication network
Methods and systems for obtaining improved joint channel estimates for a multi-user, frequency-multiplexed data transmission such as SC-FDMA or OFDM begins by estimating separate contributions of users (and / or other signal sources) to the received signal based on joint frequency domain channel estimates. A reduced data set is obtained by subtracting contributions of one or more users from the received data, leaving only the estimated contributions of the remaining users, with noise and residual estimation error signal. Time domain joint channel estimation is then performed on the reduced data set, which is feasible because the number of users has been reduced. In exemplary embodiments, the reduced data set includes only one estimated user contribution. This process is repeated to obtain time domain estimates for all of the users. The method can be repeated by using the TD channel estimates to re-estimate the user contributions and calculate revised TD channel estimates.
Owner:COLLISION COMM INC
Audio signal processing apparatus and audio signal processing method thereof
InactiveUS20160005415A1Efficient retrievalElectrophonic musical instrumentsSpeech analysisFrequency spectrumFourier transform on finite groups
An audio signal processing apparatus and an audio signal processing method thereof are provided. The audio signal processing apparatus is configured to receive an audio signal and divide the audio signal into a plurality of frames. The audio signal processing apparatus is also configured to apply Fourier Transform on each of the frames to obtain a plurality of acoustic spectra. The audio signal processing apparatus is also configured to apply Fourier Transform again on each of component combinations corresponding to respective acoustic frequencies in these acoustic spectra to obtain a two-dimensional joint frequency spectrum. The two-dimensional joint frequency spectrum has an acoustic frequency dimension and a modulation frequency dimension. The audio signal processing apparatus is also configured to calculate at least one feature of the audio signal according to the two-dimensional joint frequency spectrum.
Owner:AMES RESEARCH CENTER
Advertising method for real-time joint frequency control in combination with conventional advertising based on redirection
InactiveCN106803189AIncrease click-through conversion rateReal-time delivery strategy modificationMarketingThe InternetActivity monitoring
The invention relates to the technical field of Internet advertising and particularly to an advertising method for real-time joint frequency control in combination with conventional advertising based on redirection. The method comprises the following steps: S101, real-time data acquisition; S102, user information recording; S103, activity monitoring data analysis; S104: advertising activity integration; and S105, joint activity adjustment. The method associates a conventional advertising activity with an Internet programmed advertising activity, optimizes advertising activities in real time, reduces the number of unnecessary non-TA exposure times, can improve the click rate and conversion rate of the activities, and makes the activities highly efficient. Customers can obtain the data of the activities anytime and can modify advertising strategy in real time.
Owner:天津数集科技有限公司
Phase modulator frequency response measurement method and device
InactiveCN107219062ASolve the problem that the beat frequency cannot be directly passed by the standard photodetectorSimple structureTesting optical propertiesPhase responseMeasurement device
The invention discloses a phase modulator frequency response measurement method. Microwave signals are modulated on optical carriers by using a phase modulator to be measured so as to generate optical phase modulation signals; the optical phase modulation signals are enabled to pass through a standard optical device so that at least partial optical phase modulation signals are enabled to be converted into optical intensity modulation signals; the output optical signals of the standard optical device are converted into electric signals by using a standard photoelectric detector and the amplitude and phase information of the electric signals is extracted, wherein the frequency response of the amplitude and the phase of the standard optical device and the standard photoelectric detector is known; the frequency of the microwave signals is changed and the process is repeated so that the combined frequency response of the amplitude and the phase of the phase modulator to be measured, the standard optical device and the standard photoelectric detector can be obtained; and finally the amplitude and phase response of the standard optical device and the standard photoelectric detector is removed from the combined frequency response so that the amplitude and phase frequency response of the phase modulator to be measured can be obtained. The invention also discloses a phase modulator frequency response measurement device.
Owner:NANJING UNIV OF AERONAUTICS & ASTRONAUTICS
Audio signal processing apparatus and audio signal processing method thereof
InactiveCN105280178AElectrophonic musical instrumentsSpeech synthesisFrequency spectrumAudio signal flow
An audio signal processing apparatus and an audio signal processing method thereof are provided. The audio signal processing apparatus is configured to receive an audio signal and divide the audio signal into a plurality of frames. The audio signal processing apparatus is also configured to apply Fourier Transform on each of the frames to obtain a plurality of acoustic spectra. The audio signal processing apparatus is also configured to apply Fourier Transform again on each of component combinations corresponding to respective acoustic frequencies in these acoustic spectra to obtain a two-dimensional joint frequency spectrum. The two-dimensional joint frequency spectrum has an acoustic frequency dimension and a modulation frequency dimension. The audio signal processing apparatus is also configured to calculate at least one feature of the audio signal according to the two-dimensional joint frequency spectrum.
Owner:AMES RESEARCH CENTER
Carrier Synchronization Method Based on Symmetrical Frame
ActiveCN105406956BBit error performance impact is reducedReduce bit error rateError preventionCarrier regulationFrame basedIntermediate frequency
The invention discloses a symmetrical frame-based carrier synchronization method. The method comprises steps: 1, a pilot block and a data block are generated; 2, a data frame structure is set; 3, signals are sent at a sending end; 4, joint frequency phase offset estimation is carried out at a receiving end; 5, frequency phase offset correction signals are demodulated; and 6, Turbo code decoding is carried out. Defects that frequency offset estimation and phase offset estimation cannot be decoupled in the prior art, and influences on error code performance by large residual frequency offset cannot be effectively solved are overcome, and through arranging the symmetrical data frame structure, the problem of coupling the frequency offset estimation and the phase offset estimation in the case of joint frequency phase estimation can be solved, and the influences on the estimation performance by the large frequency offset can be reduced; and defects that the bit error rate for decoding is influenced as influences of phase offset cannot be cancelled in the case of frequency offset estimation are also overcome, and through carrying out Turbo code decoding on signals after demodulation of the symmetrical frames, the outputted code is obtained, and the bit error rate for decoding is reduced.
Owner:XIDIAN UNIV
Electric press plier
InactiveCN102120319BEasy crimpingReduce volumePortable power-driven toolsMetal-working hand toolsControl systemDisplay device
Owner:ZHANGJIAGANG CHUANGJI MACHINERY MFG
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