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97results about How to "Reduce bit error rate" patented technology

Polarization compensation implementation method of continuous variable quantum key distribution system

ActiveCN102916807ASuppresses environmental disturbancesReduce bit error rateKey distribution for secure communicationElectromagnetic transmission optical aspectsFiber-optic communicationVIT signals
The invention discloses a polarization compensation implementation method of a continuous variable quantum key distribution system. The polarization compensation implementation method comprises the following detailed steps that: a transmitting end transmits signal light and local oscillator light through one optical fiber by adopting a polarization multiplexing manner, and a receiving end separates the signal light and the local oscillator light by a polarization beam splitter, wherein a polarization feedback control method is divided into two stages, to be specific, in the light splitting detection stage, the receiving end for distribution of continuous variable quantum keys separate a part of local oscillator light out and covers the local oscillator light into a DC feedback voltage signal through a conversion circuit; and in the polarization correction stage, the receiving end controls a dynamic polarization controller by a feedback algorithm according to the DC feedback voltage to finish polarization correction. The brand-new polarization feedback control implementation method of the continuous variable quantum key distribution system, provided by the invention, has the advantages of effectively preventing the polarization state of continuous variable quantum signals from being subjected to environment interference in the optical fiber communication process, improving the system stability and promoting the practicability of the continuous variable quantum keys.
Owner:SHANGHAI JIAODA INTELLECTUAL PORPERTY MANAGEMENT CO LTD +1

Method for compensating delay difference among cells in cooperative multi-point transmission system

InactiveCN101917381AOvercoming CoMP PotentialReduce bit error rateError preventionBaseband system detailsAir interfacePhase rotation
The invention discloses a method for compensating delay difference among cells in a cooperative multi-point transmission system, mainly solving the problems that the traditional method can not naturally combine signals at air interfaces and not fully develop the potential of CoMP. The realization process comprises the following steps: (1) a user calculates out the delay difference among the cellsand delayed sampling points according to CSI-RS; (2) the user calculates out a phase rotation factor according to the delayed sampling points, and the phase rotation factor is fed back to a serving cell which shares the phase rotation factor with a cooperative cell; (3) the cooperative cell compensates the phase rotation of a signal according to the phase rotation factor; (4) the user calculates out the carrier phase deviation factor of the cooperative cell according to the delay difference, and the phase deviation factor is fed back to the serving cell which shares the phase deviation factorwith the cooperative cell; and (5) the cooperative cell compensates the phase deviation of the signal according to the phase deviation factor. The method can naturally combine signals received by theuser at the air interfaces, thereby obtaining extra array gain.
Owner:XIDIAN UNIV

Control method and control system for NAND flash memory data in solid state disk

The invention provides a control method and control system for NAND flash memory data in a solid state disk. Storage space of the solid state disk comprises multiple flash memories, wherein one memory is taken as first storage space, and the rest flash memories are taken as second storage space. The invention is characterized in that the control method comprises the steps that whether to-be-written data is important data is judged, wherein the to-be-written data will be written to a corresponding position in the second storage space if the data is not the important data, and the to-be-written data will be written to a corresponding position in the first storage space and the to-be-written data will be written to the corresponding position in the second storage space if the data is the important data; and whether new to-be-written data exists is judged, wherein the step of judging whether the to-be-written data is the important data will be started if the new to-be-written data exists, and the step will be ended if the new to-be-written data does not exist. The technical scheme provided by the invention has the advantages that a bit error rate of NAND FLASH can be effectively reduced; and data reliability of the storage system can be effectively enhanced.
Owner:深圳市先天海量技术有限公司

Method for modulator auto-IQ calibration

InactiveUS20060176975A1Reduce bit error rateTransmission noise suppressionDown conversion mixerUnity gain
A method of auto-I/Q calibration in modulator and demodulator, including DC cancellation, gain imbalance and phase error calibration is provided for implementation in a front-end circuit without the use of baseband processing signal. In modulator auto-I/Q calibration, the gain amplifier, peak detector, DC gain cell and comparator and auto-I/Q calibration control logic form a calibration loop between modulator output and input buffer. The DC test vectors for their corresponding calibrations are applied to modulator to determine I/Q mismatch. In the calibration loop, the peak detector convert the carrier leakage, differential signal power level caused by the I/Q path gain mismatch and by the local quadrature mismatch into DC signal power level. The comparator is used to measure the DC different on peak deter output under different input test vector. According to the comparing result, the auto-I/Q calibration control logic can get a set of appropriate control code to adjust the inphase and quadrature path gain, phase of LO buffer to minimize the resulting mismatch between corresponding carrier signals presented at modulator output. In demodulator auto-I/Q calibration, a baseband signal generated by dividing a reference clock is utilized as test tone to sense which path has less gain between I/Q for gain imbalance calibration. A down-conversion mixer, low pass filter, unity gain buffer and comparator form the phase calibration loop in demodulator. The mixer mixes the I/Q signal to result a DC offset used to determine which path has phase error when there is quadrature mismatch, and then the extra delay generated by delay cell is added on it.
Owner:MUCH IP

Optical fiber nonlinearity and dispersion effect compensating device with resonant cavity

The invention relates to an optical fiber nonlinearity and dispersion effect compensating device with a resonant cavity. The optical fiber nonlinearity and dispersion effect compensating device with the resonant cavity comprises an optical fiber and further comprises a circulator, an optical fiber-waveguide coupler, a silicon waveguide, a waveguide coupler, the resonant cavity and a chirp grating. The optical fiber, the circulator, the optical fiber-waveguide coupler, the silicon waveguide and the chirp grating are connected in sequence. The waveguide coupler is arranged between the silicon waveguide and the resonant cavity. The resonant cavity generates nonlinear phase shift through the nonlinear optical characteristics of the resonant cavity so as to compensate for the nonlinear effect of the optical fiber. The grating period of the chirp grating changes in the axial direction and enables incident light with different wavelengths to be reflected at different positions, so that a large group delay slope is generated, and the dispersion effect of the optical fiber is compensated for. Compared with the prior art, the optical fiber nonlinearity and dispersion effect compensating device with the resonant cavity has the advantages of real-time compensation, a small size, easy expansion and the like.
Owner:TONGJI UNIV

Communication system of intrinsic safety high-speed integrated channel for a mine

InactiveCN101741467AIncrease data transfer rateReduce bit error rateFibre transmissionSignal multiplexingLow transmission
The invention discloses a communication system of an intrinsic safety high-speed integrated channel for a mine, which is mainly used for the real-time underground and ground information exchange of a coal mine. The communication system comprises a channel ground optical transmitter and receiver and an underground optical transmitter and receiver, wherein the channel ground optical transmitter and receiver respectively comprises a transmitter and a receiver; the transmitter comprises a signal input unit, a signal output processing unit, a signal multiplexing unit, a string absorbing data interface circuit and an optical fiber receiving and transmitting module which are sequentially connected; the receiver comprises a optical fiber receiving and transmitting module, a series-to-parallel data interface circuit, a signal shunting unit, a signal receiving and processing unit and a signal output unit which are sequentially connected; and optical fiber transmission is realized through the optical fiber receiving and transmitting module between the transmitter and the receiver. The invention has the advantages of low transmission cost, high communication efficiency, simultaneously integrated transmission of the video, voice and data information of the coal mine, information sharing, high system reliability, good openness and high interference resisting capacity.
Owner:蒋继平

Sub-carrier remaining method for reducing peak-to-average power ratio and bit error rate in combined way

The invention discloses a sub-carrier remaining method for reducing a peak-to-average power ratio and a bit error rate in a combined way. The sub-carrier remaining method is characterized in that a closed mathematical expression is used for providing an optimum wave-shearing threshold and reducing the peak-to-average power ratio by linear operation in a transmitter, thereby operating a wave-shearing noise sequence by a linear mapping function to generate a sending sequence with the low peak-to-average ratio, and furthermore, a simple expression of the optimum wave-shearing threshold required when generating the wave-shearing noise sequence is provided; and a nonlinear distortion counteracting method for reducing a peak value and assistings a subcarrier wave sequence is introduced in a receiver so as to reduce the bit error rate of a system. The sub-carrier remaining method overcomes the defect that the existing method requires complex nonlinear operation to generate the sending sequence with the low peak-to-average power ratio and needs complex software simulation to generate the optimum wave-shearing threshold and the nonlinear distortion, so that the bit error rate is high. By adopting the sub-carrier remaining method, the peak-to-average power ratio can be reduced only by linear operation, and the bit error rate of the system can be reduced obviously, so that the calculation complexity is reduced greatly, and the performance of the system is improved.
Owner:UNIV OF SCI & TECH OF CHINA

Satellite cross-layer joint optimal power allocation method based on non-cooperative game

The invention relates to a satellite cross-layer joint optimal power allocation method based on a non-cooperative game. The method comprises the following steps: counting real-time information of each user on a synchronous broadband satellite physical layer; considering a satellite as a power limited system and modeling a power allocation problem as a multi-user static non-cooperative game model according to the QoS (Quality of Service) needs of different services; allocating power for the different services according to solutions and adopting corresponding encoding modes on an application layer aiming at the different services; repeating the steps at regular intervals. According to the cross-layer optimal power allocation method provided by the invention, a satellite network control center can be enabled to feed back information according to a channel state provided by a physical layer, and the QoS needs of the different services are considered; the power allocation problem is modeled as the multi-user static non-cooperative game model; meanwhile, the corresponding encoding modes are adopted on the application layer aiming at the different services according to the different cross-layer solutions, so that the communication quality of a user in a mobile communication system can be comprehensively improved, and the system performance can be improved.
Owner:BEIJING UNIV OF POSTS & TELECOMM

Remote online upgrading method and device of vehicle-mounted control terminal

PendingCN106506649ARealize remote online upgradeReduce bit error rateProgram loading/initiatingTransmissionUser codeSoftware
The invention provides a remote online upgrading method of a vehicle-mounted control terminal. The remote online upgrading method of the vehicle-mounted control terminal comprises the following steps of obtaining updating code data from an FTP server and writing the updating code data into an upgrading code file; and reading the value of an updating mark in the upgrading code file, writing code data in an updating code zone appointed by an updating code index into a user code zone in a flash memory when the value of the updating mark is equal to a preset value 3, and running a program in the user code zone after the updating code index points to another updating code zone. The invention also provides a remote online upgrading device of the vehicle-mounted control terminal. The remote online upgrading device of the vehicle-mounted control terminal comprises a control chip, a GPRS/3G/4G communication module and a storage module. The remote online upgrading method and device of the vehicle-mounted control terminal can upgrade software embedded in the vehicle-mounted control terminal, not only can reduce the bit error rate of software upgrading, but also solve the technical problem of running collapse after software upgrading failure of the vehicle-mounted control terminal and improve running stability and reliability of the vehicle-mounted control terminal.
Owner:湖南小步科技有限公司

OFDM peak-to-average ratio suppression method based on alternating direction multiplier method

The invention discloses an OFDM peak-to-average ratio suppression method based on an alternating direction multiplier method for solving the problem that the existing optimization method for reducingthe OFDM peak-to-average ratio has high computational complexity. The implementation scheme comprises: taking frequency domain OFDM signal data carrier interference as an objective function, taking the peak-to-average ratio and the free carrier power as constraint conditions, establishing a non-convex optimization model; using the alternating direction multiplier ADMM to participate in the optimization process, and seeking the optimal solution, wherein the optimization process consists of two schemes, the ADMM method is directly used for solving in scheme 1, and a KKT point of an optimizationmodel can be guaranteed to be converged in the case of convergence. In the scheme 2, the optimization model is relaxed to obtain a relaxation model to guarantee the convergence, and the KKT point of the optimization model is infinitely approached in the case that the parameters are properly selected. Compared with the existing peak-to-average ratio suppression method, the OFDM peak-to-average ratio suppression method has the advantages of being able to obtain a smaller and more constant peak-to-average ratio, improving the system error rate performance and reducing the computational complexity, and the OFDM peak-to-average ratio suppression method is applied to the technical field of communication to improve the transmission quality of the communication system quality.
Owner:XIDIAN UNIV +1

Single bus communication signal isolation circuit

PendingCN109525475AEliminate the effects of signal interferenceReduce bit error rateBus networksPull-up resistorEngineering
The invention discloses a single bus communication signal isolation circuit, wherein a first pull-up resistor is connected to a host interface end; the in-phase input end of a first comparison unit isconnected to the host interface end, and the inverting input end of the first comparison unit is connected to a first reference voltage; the control end of a first optocoupler is connected to the output end of the first comparison unit; a second pull-up resistor is connected to a slave interface end, the collector of the first optocoupler is connected to the slave interface end, and the emitter of the first optocoupler is connected to the ground at the slave interface end; the in-phase input end of a second comparison unit is connected to the slave interface end, and the inverting input end of the second comparison unit is connected to a second reference voltage; the control end of a second optocoupler is connected to the output end of the second comparison unit, the collector of the second optocoupler is connected to the host interface end, and the emitter of the second optocoupler is connected to the ground at the host interface end. The circuit solves the technical problem that thehost end and the slave end cannot be effectively isolated in the single bus communication process.
Owner:SUZHOU LUZHIYAO TECH
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