182results about How to "Short sync time" patented technology

The invention relates to a network video monitoring system based on FPGA chaotic encryption, comprising a server terminal, a client terminal and a system configuration terminal. The server terminal comprises a plurality of cameras, a video server, an encryption module and a signal sending module; the client terminal comprises a signal receiving module, a decryption module and a client terminal player; video frequency collected by the plurality of cameras is coded by the server, then input into the encryption module via the Ethernet and sent to the client terminal via the signal sending module after encrypted; the signal receiving module of the client terminal receives the encrypted video data and then sends the data to the decryption module for processing and finally the client terminal player plays the video data; the encryption module and the decryption module are respectively an FPGA encryption board and a decryption board; the encryption process and the decryption process of the encryption module to video flow are as follows: the encryption module adopts a CPRS array which is cut and operates with a plain text data module 2, and then sent; and the receiving terminal of the decryption module obtains the same CPRS array, and then operates with a cryptograph module to realize decryption.

The present invention discloses a method for modulating digital television ground broadcasting transmitter based on insertion training sequence and LDPC code, wherein the method comprises the following steps: 1) forming an FFT coded data block with the input bit flow through LDPC coding; 2) switching the FFT coded data block to a time domain discrete coded data sample block through IFFT; 3) forming a complex training sequence discrete sample block with a mode that a training sequence is used as a real part sequence and an operational indicator sequence is used as an imaginary part sequence; 4) continuously repeating the complex training sequence for four times to form a time domain insertion training sequence discrete sample block; 5) directly overlapping the time domain discrete coded data sample block with the time domain insertion training sequence discrete sample block for forming a time domain insertion training sequence coded data block; 6) inserting a circulating prefix into the time domain insertion training sequence coded data block for forming a signal frame; 7) forming a signal frame pulse with a square-root raised cosine roll-off filter; and 8) upconverting the baseband signal to the carrier.

The invention discloses a space frequency modulation method for digital TV terrestrial broadcasting transmitter based on embedding training sequence and LDPC coding comprising: 1) coding input bit stream by LDPC and forming coding data block on frequency domain; 2) then demodulating by space-frequency coder and regulating time for synchronization; 3) converting data block after space-frequency modulation to time domain discrete data sample value block via IFFT; 4) training sequence serving as real part, service index sequence serving as imaginary part sequence, constituting discrete sample value block of plural training sequence; 5) repeating continuously the plural training sequence four times to form discrete sample value block of time domain embedded training sequence; 6) superposing the space-frequency modulated time domain discrete data sample value block and time domain embedding training sequence discrete sample value block to form space-frequency modulated time domain embedded training sequence data block; 7) inserting cyclic prefix as protective interval and forming signal frame; 8) pulse shaping to signal frame using square root raised consine roll-off filter; 9) up-converting base band to carrier.

The invention relates to a drive train for a motor vehicle, comprising: an internal combustion engine, which has a crankshaft; a manual transmission, which is operated in an automated manner and which has a transmission input shaft and a transmission housing, which transmission housing forms a clutch bell housing together with the internal combustion engine; a torsionsal vibration damper, which is accommodated on the crankshaft by means of an input part; and a friction clutch, which is arranged after the torsional vibration damper, is connected to an output part of the torsional vibration damper, is accommodated in the clutch bell housing, is connected to the transmission input shaft in a rotationally locked manner, and is operated in an automated manner. In order to shorten the shifting times and thus the interruption times of a traction force of the automated manual transmission, the friction clutch is accommodated in a wet space sealed off from the torsional vibration damper and from the clutch bell housing by means of a cover and has an input-side outer plate carrier that accommodates input plates in a rotationally fixed manner and an output-side inner plate carrier that accommodates output plates layered in alternation with the input plates in a rotationally fixed manner, and a flange part is provided in the wet space, which flange part is connected to the output part in a rotationally locked manner, drives the outer plate carrier, and has a centrifugal force pendulum having pendulum masses arranged radially outside the outer plate carrier.

An embodiment of the invention provides a wireless communication method which is applied to a satellite, wherein the method comprises the steps of transmitting configuration information of a trackingreference signal TRS of at least one wave beam to a terminal, wherein the configuration information is at least used for indicating a first time domain position of the TRS transmitted from a satellite; wherein the TRS is used for synchronization between the terminal and the satellite; and the first time domain position is used for determining the awaking time of the terminal in a radio resource control RRC idle state by the terminal.

The invention discloses a method for transmitting a digital mobile broadcast signal, which is a transmission proposal of time domain and frequency domain mixing. The method for transmitting a digital mobile broadcast signal disclosed by the invention has the advantages of low peak-to-average power ratio, short synchronization time, fading noise influence resistance, controllable multi-service etc.

The invention provides a clustering synchronization of complex networks based on community partitioning for pinning node selection, which relates to the technical field of complex network and nonlinear control. Firstly, a complex network of N nodes composed of m community sub-networks is constructed, and the synchronization manifold of the complex network is set up to obtain the synchronization error of each community sub-network node. Then the pinning nodes of each community in the complex network are selected and a negative feedback controller is applied to the pinning nodes to obtain the synchronization error system of the controlled complex network. Finally, the Lyapunov function is designed for the synchronization error system, which proves that the complex network can achieve clustering synchronization. The invention provides a method for selecting a pinning node of complex network clustering synchronization based on community division, which has better synchronization effect, shorter synchronization time, relatively dispersed pinning node position and smaller pinning action range.

The invention discloses a modulation method for digital TV terrestrial broadcasting transmitter based on time domain training sequence and LDPC coding comprising: 1) coding input bit stream by LDPC and forming FFT coding data block on frequency domain; 2) converting FFT coding data block to time domain discrete coding data sample value block via IFFT; 3) inserting cyclic prefix as protective interval to time domain discrete coding data sample block and forming time domain cyclic prefix discrete coding data sample block; 4) continuous four time domain cyclic prefix discrete coding data sample value blocks constituting a frame body; 5) training sequence serving as real part of plural training sequence, service index sequence serving as imaginary part sequence to constitute discrete sample value block of plural training sequence; 6) inserting the discrete sample value block (frame head) of plural training sequence in signal frame for forming frame body;7) pulse shaping to signal frame using square root raised consine roll-off filter; 8) up-converting base band to carrier.

The present invention discloses a hopping-rate-related and interval-related shift frequency-hopping communication method. An emission, wherein different hooping rates and different frequency-hopping interval durations are adopted to represent different data information, namely, hopping-rate-related and interval-related. A receiving portion, wherein two identical signal channels are adopted, and receiving frequencies of the two signal channels are different from each other in one frequency-hopping position. When the signal channels receive signals, high electrical levels are output; electrical level output by the two signal channels are determined whether synchronous or not by an synchronization determination circuit, and a binary synchronous working mode is realized, solving of problem of initial synchronization alone is needed and completion of synchronization of carrier waves is not needed. With synchronous normal operation, change rules of the information can be obtained from the synchronization, and the data information is obtained by identifying regular changing information; the receiver portion has no local clocks, and an operation status keeps dynamic and binary followings with the emitted frequencies. The hopping-rate-related and interval-related shift frequency-hopping communication method is advantageous in that dodging interferences on purpose is not needed, synchronization time is shorter, and data transmission is more flexible.

The invention discloses a multiuser OFDM modulation method based on embedded training sequence and LDPC coding, which includes the following steps: 1) each user inserting zero even in its own training sequence to form discrete FFT training sequence block; 2) each user performing LDPC coding to its own input data bit stream to further form an FFT coding data block; 3) directly superimposing the discrete FFT training sequence block and the FFT coding data block to form an FFT embedded training sequence coding data block; 4) adopting IFFT to switch the FFT embedded training sequence coding data block into a time-domain discrete sample block; 5) taking circulating prefix as guard interval to insert into the time-domain discrete sample block to from a signal frame; 6) using a Raised Cosine Roll-off Filter to perform pulse shaping to the signal frame; 7) upconverting the baseband signal to carrier. The method has advantages of short synchronization time, channel dwindle resistance and multiuser disturbance resistance and the like.

The invention is applicable to the technical field of satellite navigation and positioning, and provides a BOC (Binary Offset Carrier) signal acquisition method and a baseband synchronous receiver. The method comprises steps: BOC intermediate frequency signals are received; a quadrature demodulation mode is adopted to mix the BOC intermediate frequency signals with local carriers for carrier stripping, and baseband BOC signals are obtained; according to the modulation order N of the baseband BOC signals, a pseudo random noise (PRN) code generated by a local pseudo code generator is subjected to signal decomposition to obtain N sub PRN codes; a first sub PRN code and an Nth sub PRN code are taken out to be divided to two paths to be correlated with a baseband BOC signal branch to obtain a sub mutual-correlation branch, and through reconstructing the sub mutual-correlation branch, non-coherent integration is carried out to obtain an acquisition result. The structure is simple, the erroracquisition rate is low, the sensitivity is higher, quick BOC acquisition can be completed, a BOC signal autocorrelation side peak can be eliminated basically, and the BOC signal narrow correlation characteristics are kept.

The invention provides a method for reducing synchronization time of frequency-hopping communication. With the method, the synchronous performance of the frequency-hopping signal can be improved obviously. According to the technical scheme, the method comprises: with a frequency-hopping synchronization circuit, after a frequency band where a frequency-hopping signal is located is determined, channel division is carried out on a frequency band covered by the frequency-hopping signal based on a frequency-hopping pattern and a frequency-hopping frequency point, times of occurrence of signals in all channels are recorded, recorded frequency-hopping points are mapped into a sequence generating a frequency-hopping pattern, and the sequence correlates with a generated periodic sequence generating a frequency-hopping pattern and a position of a received signal in the frequency-hopping pattern is found out; and after the position of the signal in the frequency-hopping pattern is found out, an occurrence frequency point and occurrence time are determined by combining a local counter and a frequency point and time of occurrence of a next signal are determined, so that coarse synchronization is completed. After de hopping and demodulation are carried out on the signal after coarse synchronization, a precise frequency-hopping frequency point switching time is obtained, thereby realizing precise synchronization and tracking of the frequency-hopping signal.

The invention discloses a digital communication method based on hexadecimal 8-8 constellation diagram mapping, and relates to the technical field of wireless measurement and control communication. Based on the communication method of the invention, a 16APSK signal constellation diagram is designed, the constellation diagram is designed into eight constellation points on the inner ring and eight constellation points on the outer ring, a differential encoding mode is adopted to carry out constellation diagram phase mapping, amplitude modulation is adopted to carry out constellation diagram amplitude mapping, and an amplitude mapping and differential phase mapping method is adopted at a demodulation end to carry out demodulation judgment. According to the invention, transmission of burst high-capacity detonation data can be ensured within tens of microseconds of survival time. The proposed novel 16APSK (8-8 constellation diagram) telemetry signal has the characteristics of high bandwidthefficiency, high energy efficiency, suitability for high-code burst rate data transmission and the like, and is a novel telemetry system capable of realizing rapid synchronization and low-complexity receiving demodulation.

The invention discloses an image processing-based big data analysis method and system, and aims to solve the problem of high difficulty of image processing database expansion in the prior art. The method comprises the steps of classifying first image data by nodes to obtain second image data; judging the legality of the second image data by the nodes; sending the legal second image data by the nodes; receiving the legal second image data and performing writing in a block chain according to the legal second image data, wherein the block chain comprises a sample data set consisting of the secondimage data; and synchronizing the block chain by the nodes and obtaining the sample data set. According to the method, an image processing database is established by utilizing a block chain technology; the user nodes can participate in establishment of the image processing database; an image processing data set is expanded; node participants can synchronize the image processing data set in real time, so that the whole sample data set of image processing data is expanded; and the method is suitable for the field of big data.

The invention discloses a multimedia broadcast mobile signal robust framing modulation method, and belongs to a time domain and frequency domain mixed framing modulation scheme. The multimedia broadcast mobile signal robust framing modulation method has the advantages of low peak-to-average power ratio, short synchronous time, robustness, controllable multi-service and the like.

The invention discloses an anti-noise digital broadcast wireless signal transmitting method, and relates to a time domain / frequency domain mixed scheme. The anti-noise digital broadcast wireless signal transmitting method has the advantages of low peak-to-average power ratio, short synchronization time, resistance to channel noise, controllable multiple services and the like.

The invention provides a terminal and server file synchronization method and device. The terminal and server file synchronization method comprises the steps of selecting dicing scheme from a dicing scheme list of a terminal according to the current network available bandwidth and the redundancy elimination capability and processing overhead of the terminal; dicing a file to be synchronized into a plurality of data blocks according to the dicing scheme; creating an identifier for each data block, and transmitting the identifiers to a server; receiving the identifier by the server, comparing the identifiers with identifiers corresponding to data blocks in the server, determining whether the data blocks to which the identifiers correspond exist in the server, and feeding back a determination result to the terminal; and synchronizing the file to be synchronized to the server by the terminal according to the feedback. The technical scheme provided by the embodiment of the invention can be used for dynamically selecting the dicing scheme for dicing the file to be synchronized, the data synchronization time is ensured to be the shortest, and the synchronization efficiency is improved.

The invention discloses a method for framing and modulating wireless multimedia broadcast signals, which is a framing and modulating scheme mixing a time domain with a frequency domain. The method for framing and modulating wireless multimedia broadcast signals has a signal generation mode and a signal selection method which are easy to process and recover an original signal obtaining an OFDM (Orthogonal Frequency Division Multiplexing) signal at a receiver end, and has the advantages of being low in peak average power ratio, short in synchronization time, resistant to channel fading, capableof controlling various businesses, etc.

Provided are a hybrid environmental sanitation vehicle ATM speed changing box power takeoff device and a control method thereof. The device comprises a power takeoff, a driving motor, a power takeoffelectromagnetic valve power supply switch (7) , a power takeoff electromagnetic valve (8) and a whole vehicle controller. The driving motor is arranged between a clutch and a speed changing box, a driving motor output shaft is connected with a speed changing box input shaft (1), a power takeoff input shaft (4) is connected with a speed changing box intermediate shaft (3), a power takeoff driving air cylinder (6) is connected with a power takeoff shift fork (9), the power takeoff electromagnetic valve (7) is connected with the power takeoff electromagnetic valve (8), and the power takeoff electromagnetic valve (8) is respectively connected with the power takeoff driving air cylinder (6) and an air cylinder (10) of an environmental sanitation vehicle; the method includes the following stepsthat a clutch is separated, the power takeoff electromagnetic valve (8) is started, it is judged whether the vehicle is successfully in gear or not, and the gear engaging is finished. The abrasion ofthe clutch is reduced, and the service life of the power takeoff is prolonged.

The invention discloses a method for framing and modulating anti-fading wireless multimedia broadcast signals, which is a framing and modulating scheme that time domains and frequency domains are mixed. The method for framing and modulating the anti-fading wireless multimedia broadcast signals disclosed by the invention has the advantages of low peak-to-average power ratio, short synchronization time, anti-fading property, controllable multi-service and the like.

The invention discloses an anti-interference wireless multimedia mobile broadcast signal framing modulation method, which is a time domain / frequency domain combined framing modulation scheme. The anti-interference wireless multimedia mobile broadcast signal framing modulation method has the advantages of low peak-to-average power ratio, short synchronization time, resistance to the influence of noises, multi-service controllability and the like.

The invention discloses a multimedia broadcasting wireless signal anti-interference framing modulation method which is a time domain and frequency domain mixed framing modulation scheme. The multimedia broadcasting wireless signal anti-interference framing modulation method provided by the invention has the advantages of low peak average power ratio, short synchronizing time, anti-interference, capability of controlling multiple services, and the like.

The invention discloses a modem based disperse pilots, and relates to the modem technology of a communication system applying high-order modulation in the communication field. According to the modem, a frame format is improved on the basic structure of the communication system. Through addition of the disperse pilots, the carrier recovery complexity is reduced, and the carrier recovery performance of the modem is improved. The realization process of the modem is simple and effective. The modem is very suitable for the communication system applying a high-order modulation mode.

The invention relates to a network video monitoring system based on FPGA chaotic encryption, comprising a server terminal, a client terminal and a system configuration terminal. The server terminal comprises a plurality of cameras, a video server, an encryption module and a signal sending module; the client terminal comprises a signal receiving module, a decryption module and a client terminal player; video frequency collected by the plurality of cameras is coded by the server, then input into the encryption module via the Ethernet and sent to the client terminal via the signal sending moduleafter encrypted; the signal receiving module of the client terminal receives the encrypted video data and then sends the data to the decryption module for processing and finally the client terminal player plays the video data; the encryption module and the decryption module are respectively an FPGA encryption board and a decryption board; the encryption process and the decryption process of the encryption module to video flow are as follows: the encryption module adopts a CPRS array which is cut and operates with a plain text data module 2, and then sent; and the receiving terminal of the decryption module obtains the same CPRS array, and then operates with a cryptograph module to realize decryption.

The invention discloses a distributive beam forming method based on closed loop frequency offset control, and is characterized by comprising the following steps: (1) a reception base station broadcasts radio frequency carrier frequency during initialization, all the nodes carry out phase rectification, transmission signals are overlapped at the reception base station in a short time, and the power gain reaches the maximum value; and (2) the reception base station broadcasts feedback signals to all the nodes while effective communication is realized, and the points randomly adjust the respective carrier wave phase. The frequency offset of the nodes is controlled by utilizing the method, thereby the gain of the reception base station is maintained and the purpose of stable communication for a long time is achieved.

The invention discloses a robust mobile signal framing modulation method for a multimedia broadcast single frequency network, and relates to a mixed framing modulation scheme of the space domain, the time domain and the frequency domain. According to the training sequence optimization design, the signal generating scheme and the signal selecting method of the robust mobile signal framing modulation method for the multimedia broadcast single frequency network, OFDM signals can be processed and recovered at a receiver end easily to obtain original signals of the OFDM signals. The robust mobile signal framing modulation method for the multimedia broadcast single frequency network has the advantages of being low in peak-to-average power ratio, short in synchronization time, resistant to channel fading, multiple in controllable service and the like.

The invention discloses a method for framing and modulating anti-interference wireless multimedia broadcast signals in a single frequency network. The method provides a framing and modulating scheme mixing a space domain, a time domain and a frequency domain. According to a training sequence optimal design, a signal generation pattern and a signal selection method of the method for framing and modulating the anti-interference wireless multimedia broadcast signals in the single frequency network, an original signal of an OFDM signal can be easily obtained through processing and recovery on a receiver terminal. The method for framing and modulating the anti-interference wireless multimedia broadcast signals in the single frequency network has the advantages that the peak-to-average power ratio is low, synchronization time is short, channel fading is prevented, and multiple services can be controlled.

The invention discloses a robust transmission method of digital broadcast mobile signals, which is a mixed transmission scheme of time domain and frequency domain. The method has the advantages of low PAPR (peak-to-average power ratio), short synchronous time, robustness, multiple controllable services and the like.

The invention discloses an anti-interference multimedia wireless broadcast signal framing modulation method, which is a time domain / frequency domain hybrid framing modulation scheme. The anti-interference multimedia wireless broadcast signal framing modulation method has the advantages of low peak-to-average power ratio, short synchronization time, anti-interference performance, multi-service controllability and the like.

The invention discloses a multimedia broadcast mobile signal anti-interference framing modulation method and in particular relates to a framing modulation scheme with mixing of time domains and frequency domains. The multimedia broadcast mobile signal anti-interference framing modulation method has the advantages that the peak-average power ratio is low, the synchronization time is short, the interference resistance is achieved, and the multiple services can be controlled and the like.