52results about How to "Improve time synchronization" patented technology

A computer implemented method and apparatus utilizing a multi-diversity synchronization technique for improving time synchronization in wireless applications, such as TDMA applications is disclosed. The multi-diversity synchronization technique utilizes cross-correlations between multiple diverse received signals to determine relative offsets between the signals. The signals are then time aligned. An absolute synchronization word location is determined using the time aligned signals and is used along with the relative offsets to determine respective synchronization word locations for each received signal in an accurate, efficient and improved manner.

Disclosed are systems and methods for improving image recognition by using information from sensor data. In one embodiment, the method comprises receiving one or more sensor records, the sensor records representing timestamped sensor data collected by a sensor recording device; selecting an event based on the sensor records; identifying a time associated with the event; retrieving a plurality of timestamped video frames; synchronizing the sensor records and the video frames, wherein synchronizing the sensor records and the video frames comprises synchronizing the timestamped sensor data with individual frames of the timestamped video frames according to a common timeframe; and selecting a subset of video frames from the plurality of timestamped video frames based on the selected event.

A method and apparatus for delivering interactive television (ITV) data by using the same TV scan line that also carries closed caption data. The ITV data is inserted into the scan line with CC data by detecting a gap associated with a first CC data unit. If the gap is large enough to contain all of the group of ITV data units then electronically insert the entire group of ITV data units into the gap. If the gap is not large enough to contain the entire group of ITV data units, insert a subset of the entire group of the ITV data units into the gap and continue to the gaps associated with successive CC data units, inserting subsets of the ITV data into subsequent gaps until the entire ITV message has been inserted into the gaps between CC data units.

Improved time synchronization is provided among the devices of an industrial process control system, e.g., a Substation Automation system, during a temporary absence of a system reference time. Hence, disruption of time-critical protection and control functions due to re-synchronization following the temporary absence of the system reference time is avoided, and the availability of time-critical functions configured on the devices is increased. During normal operation, a device of the system records an offset or discrepancy between the system reference time and an internal local clock of the device for a period of several hours. As soon as the system reference time breaks down, the device starts predicting the offset or drift between its local clock and the unavailable system reference time based on the recorded offset history. As a transient clock master, the device then distributes an approximated or transient system reference time, based on the device's local clock corrected for the predicted offset, to other devices of the system which, in turn, run time-critical protection and control functions.

A high-time-synchronization multichannel fiber bragg grating sensing system comprises a broadband fluorescent light source, a three-terminal circulator, an optical divider, a 1*4 optical switch group, a fiber bragg grating sensor group, a sensing signal demodulating device and a computer. On the basis of the advantages of high wavelength resolution precision, high demodulating speed and the like of an existing multichannel fiber bragg grating sensing system, high time synchronization in signal acquisition and processing of each channel can be realized in multichannel multi-point sensing measurement, and moreover, the high-time-synchronization multichannel fiber bragg grating sensing system is high in reliability.

Provided are a time synchronization method allowing a fixed time delay and a bridge that is interposed between a master and a slave, according to the method. In the bridge, a predetermined time after the synchronization packet is set as an output time of the synchronization packet and the synchronization packet is output at the output time. Accordingly, it is possible to delay synchronization packets in the bridge for the same time, thereby increasing the time synchronization precision.

According to various embodiments of the disclosure, systems, methods and apparatuses are provided for using ranging to improve network efficiency. In particular, various embodiments of the disclosure provide ranging to improve local clock time synchronization. According to one embodiment, a method for synchronizing a plurality of nodes on a communication network is provided, comprising: exchanging local clock times between a first node and a second node over the communication network; performing a ranging method between the first and second nodes based on the local clock times exchanged between the first and second nodes, wherein the ranging method results in an estimated propagation delay between the first and second nodes; and adjusting the local clock times of the first and second nodes based on the estimated propagation delay, thereby resulting in a synchronized local clock time at the first and second nodes.

A synchronization method, a control system and a slave unit for the time synchronization of at least two slave units, in which the slave units and the master unit are connected by two signal lines. A signal transmitted by the master unit returns to the master unit after passing through all the slave units. Two independent counters are provided in each slave unit, these counters being activated by reception of a reference signal transmitted by the master unit. The first time counter counts the time since the receipt of the reference signal via the first signal line and the second time counter counts the time since the receipt of the reference signal via the second signal line. The counter contents are read out as soon as the sum of the counter contents reaches a signal throughput time transmitted previously by the master unit.

The invention relates to a synchronous method of a multi-carrier communication system and a device thereof. A non-repeated polynomial sequence synchronous symbol is sent out by a sending terminal. Polynomial conversion treatment is implemented on the received signal at a receiving end, and frame synchronization and frequency offset estimation are implemented. An estimated frequency offset value substitutes into an initial receiving signal for the compensation. Finally, the compensated receiving signal is interrelated with a local synchronous sequence of the synchronous symbol length to finish the symbol synchronization process. The non-repeated polynomial sequence is only sent out at the sending terminal as the synchronous symbol for the timing estimation and the frequency offset estimation. On the basis of not infecting the frame synchronization and the frequency offset synchronization, the timing synchronous precision of the symbol is greatly improved. And the synchronous method and the device thereof have the advantages of simple algorithm, low calculation complexity and good synchronous effect.

The embodiment of the invention discloses a method for sending time synchronization information, comprising the following steps: receiving first time synchronization information from an optical line terminal (OLT), wherein the first time synchronization information is the local time synchronization information of the OLT, and comprises 1 pulse per second (1PPS) signals and time of day (ToD) signals; calculating the average period of the multiple continuous 1PPS signals in the first time synchronization information, and regulating the period of the next 1PPS signal or the next group of 1PPS signals to be the average period; and configuring the ToD signals and the 1PPS signals which are subjected to the period regulation into second time synchronization information and sending the second time synchronization information to a user terminal device so as to carry out time synchronization processing for the user terminal device. The embodiment of the invention also provides a system and device for sending time synchronization information.

The invention relates to a network path delay measurement method and device and a time synchronization system. The method includes: obtaining triggering data; Obtaining a preset state machine information table; Acquiring a state machine from the preset state machine information table according to the trigger data, and generating feedback information according to the state machine; Queuing the feedback information in a task queue to obtain a queuing result, and detecting the queuing result according to preset time to obtain a detection result; And performing state processing on the state machine according to the detection result to obtain a timestamp, and calculating path delay measurement data according to the timestamp. According to the invention, through task timing queue scheduling, states of all state machines in delay measurement are jumped to the interface in a unified manner; and a task timer is started in any timing service queue for timing processing, so that the uncertainty of system call delay is reduced, the execution efficiency of the system is finally improved, and the time precision of path delay measurement and time synchronization is improved.

The embodiment of the invention provides a time-frequency synchronization method and apparatus of an aviation broadband communication system based on OFDM. The problem that the estimation range of a typical Moose estimation method is insufficient is solved by an integral multiple frequency offset estimation scheme of firstly performing differential correlation based on subcarriers and performing correlation operation with a pre-stored sequence to find an integral multiple frequency offset fold. In view of time synchronization with large frequency offset, although the typical SAC method is not sensitive to the frequency offset, the erroneous judgment probability of the method is relatively large. According to the time-frequency synchronization method and apparatus provided by the invention, a rough synchronization position is found by SAC at first, frequency offset compensation and sliding correlation operation are carried out on the pre-stored sequence to find an accurate synchronization position corresponding to a maximum related peak position. The time synchronization performance is greatly improved.

The invention belongs to the field of power systems and relates to an intelligent power grid distribution and autonomous wide-area timing method. The method of the invention comprises: constructing an intelligent power grid wide-area time synchronization system, wherein each of the plant stations and scheduling centers in the system represents a time node, and each time node has an independent satellite synchronous clock responsible for keeping the time synchronization of all sets of power equipment in the node and releases time synchronization information to other time nodes in the wide-area time synchronization system through a time communication network; and keeping the time synchronization of the time nodes by the time information of the satellite synchronous clocks when the satellite synchronous clocks work normally, and correcting the time information of a local crystal oscillator color by the time synchronization information released by other time nodes in the wide-area time synchronization system to keep the time synchronization of the node when the satellite synchronous color of a certain time node fails to work. The method of the invention provides a new through for the time synchronization of a power grid and can improve the time synchronization performance of the intelligent power grid effectively.

The invention discloses a node cooperative work method based on the sensing direction guide in an Internet of things environment and mainly relates to an effective realization method monitored by an object in a multimedia sensor network. Based on a sensing node perceived radius theory and a video sensing model which are provided by the invention, the method is combined with practical application and meets different practical monitoring requirements according to two work modes of group and individual provided by different scenes. By elaborating a direction guiding method in the wireless multimedia sensor network from two views of theory and practicability and combining the characteristics of easy manipulation, conciseness, high efficiency, cost saving, low expenditure and energy consumption, high flexibility and the like of the wireless multimedia sensor network, the invention provides constructive suggestions for the application of the multimedia sensor network in the monitoring field.

The invention discloses a collinear optical parametricamplification method and a collinear optical parametricamplification device, and belongs to the technical field of ultrafast laser. A BaF2 crystal is inserted between two beta-BaB2O4 crystals, generated femtosecond pump light and broadband signal light are synchronously and collinearly transmitted into the first beta-BaB2O4 crystal for first optical parametricamplification, the amplified femtosecond signal light and femtosecond idle frequency light are generated, and at the moment, the femtosecond pump light exceeds the femtosecond signal light, and the femtosecond signal light exceeds the femtosecond idle frequency light; after the light passes the BaF2 crystal, the femtosecond idle frequency light exceeds the femtosecond signal light, and the femtosecond signal light exceeds the femtosecond pump light; and the light passes the second beta-BaB2O4 crystal for second optical parametricamplification, and the femtosecond pump light, the femtosecond signal light and the femtosecond idle frequency light achieve time synchronization. By the method and the device, group velocity mismatch among the pump light, the signal light and theidle frequency light is compensated simultaneously, the time synchronization of three optical signals is improved, and the gain spectrum width and the conversion efficiency of a collinear optical parametricamplifier are improved.

Present invention relates to a time frequently synchronizing method for receiving data short distance wireless networks, belonging to wireless communication technology field. It contains receiving RF transmitted signal, frequency conversion and sampling to become baseband receiving signal, utilizing training sequence periodicity to estimate code element cycle reciprocal decimals times frequency offset, according to real system frequency deviation region to determine the value taking possibility for code element cycle reciprocal integral multiple frequency offset, according to each hypotheses possible frequency offset to proceed frequency offset compensation to receiving signal, then to proceed sliding correlation with local sequence, according to correlative maximum value to determine frequency offset estimated value and time synchronizing position, thereby realizing time frequently combined synchronizing position. Said method reduces calculated amount in time and frequency synchronism, to make receiver having more low power consumption.

The invention discloses a Bluetooth headset with a voice encryption function and a voice encryption method of the Bluetooth headset. The Bluetooth headset comprises a Bluetooth control circuit, a synchronizing signal encoder, a synchronizing signal decoder, a voice encryption circuit and a key management circuit, wherein the synchronizing signal encoder, the synchronizing signal decoder, the voice encryption circuit and the key management circuit are connected with the Bluetooth control circuit. The voice encryption method of the Bluetooth headset comprises processes of simulation language encryption, synchronous encryption and dynamic encryption. The Bluetooth headset with the voice encryption function and the voice encryption method of the Bluetooth headset have the characteristics of high confidentiality, high synchronicity, good convenience in use, wide application range and low cost.

The invention discloses a time synchronization method based on ELM, and the method comprises the steps: collecting a received signal, and constructing a training data set i=1,2,...,Nt; constructing anetwork model based on ELM time synchronization; training the network model based on ELM time synchronization offline and storing the model and parameters; running the network model based on ELM timesynchronization on line to obtain a time synchronization estimation value. According to the time synchronization method disclosed by the invention, the time synchronization network model is constructed by virtue of the ELM network, and compared with a classical cross-correlation synchronization method, the time synchronization performance of the system can be effectively improved; when nonlinear distortion exists in the system, the time synchronization method is still applicable.

A method of improving the synchronization of the timing of a plurality of physically coupled print engines by detecting and eliminating misleading indications of a non-synchronized print engine that are essentially minimal variations caused by disturbances to the printer such as torque disturbances, power line voltage or frequency variations, etc. using a chosen number of consecutive changes in the time delay to result in the time delay of the receiver being handed off from one engine or module to a sequential engine or module before a machine error is declared. This method notes that a speed variation is sufficiently large or if a signal is reported that a module, operating within its speed specifications but near the end the limit of that specification, had been subjected to a small incremental change in module speed resulting in that module operating outside its specifications and takes corrective actions or not depending on the magnitude and or source of the variation.

A method of synchronizing multi-carrier systems is provided, wherein the method comprises inserting a predefined frequency domain signal into a signal on a transmitter side of a multi-carrier system and multi-carrier modulating the signal. Furthermore, the method comprises transmitting the multi-carrier modulated signal via a carrier channel to a receiving side of the multi-carrier system, and synchronizing the multi-carrier modulated signal by using the predefined frequency domain signal portion of the multi-carrier modulated signal.

A computer vision based land surface settlement monitoring method comprises the following steps of A) instrument arranging, B) equipment debugging, C) parameter setting and D) monitoring and result storing. Before start of monitoring, a first frame of image is captured, an LED lamp is marked and serves as a tracking template, the pixel center of a template area serves as a reference point for calculating settlement of the point, and a monitoring area of the point is marked according to the pre-estimated settlement; after start of monitoring, a monitoring area of a second frame of image is searched for optimal match of the LED lamp template, a pixel displacement difference is calculated from the pixel center position of the first frame of template area and the pixel center position of the template area obtained by matching in the present frame, and the second frame of image is updated as a new reference point; the pixel displacement difference of the LED lamp template between two adjacent frames of images are calculated repeatedly in the above way; and pixel displacement of the LED lamp is calculated by accumulation of the pixel displacement differences, and a practical settlement process of the LED lamp is calculated by proportional relation between the practical size and the pixel size.

Apparatus, and an associated method, for a radio communication system having a sending station and a receiving station. The sending station sends data pursuant to a communication service and ultrawide band signals pursuant to a selected time-hopping sequence. An ultrawide band signal detector is positioned at the receiving station. The ultrawide band signal detects the ultrawide band signal transmitted thereto. Correlation is made between the detected ultrawide band signal and a locally-generated replica signal. Correlations therebetween are used to facilitate various receiving station operations, such as equalization operations upon received data, time synchronization of the receiving station to the sending station, and position determination of the positioning of the receiving station.

The invention provides a base station time synchronization method and a base station time synchronization device. The method comprises the following steps: judging whether a base station moves or not; when the base station moves and the movement distance is greater than or equal to a first distance, repositioning the position of the base station; when a position measurement mark in the time data TOD received in a first continuous time is invalid, synchronizing the time of the base station with an external real clock. According to the method and the device, the drift deterioration of the clock of the base station in the overall moving process is greatly improved; the time synchronization performance of the base station in a moving state is improved.

The invention discloses a radar video data fusion method, electronic equipment and a computer readable storage medium, and the method comprises the steps: carrying out the collection of video data and radar data, and obtaining a video frame and a radar frame; determining a radar frame closest to the time of the current video frame, and taking the determined radar frame as a matched radar frame; and fusing the current video frame and the matched radar frame. The time synchronization of the radar data and the video data can be improved.

The embodiment of the invention discloses a data determination method and device and a vehicle-mounted terminal. Wherein the main controller is respectively connected with the at least two image acquisition devices, each image acquisition device is connected with the corresponding processor, and the main controller is connected with each processor. The method comprises the following steps: a maincontroller acquires an image acquired by each image acquisition device in response to a first image acquisition instruction, acquires a timestamp of the image sent by each processor, and associates the image with the timestamp according to a preset corresponding relationship between the image acquisition devices and the processors; wherein the first image acquisition instruction is used for indicating each image acquisition device to acquire an image at an associated moment; wherein the timestamp is determined when the processor determines that the image acquisition device acquires the image.By applying the technical scheme of the embodiment of the invention, the time synchronism among the images acquired by different cameras can be improved.

Disclosed are systems and methods for improving image recognition by using information from sensor data. In one embodiment, the method comprises receiving one or more sensor records, the sensor records representing timestamped sensor data collected by a sensor recording device; selecting an event based on the sensor records; identifying a time associated with the event; retrieving a plurality of timestamped video frames; synchronizing the sensor records and the video frames, wherein synchronizing the sensor records and the video frames comprises synchronizing the timestamped sensor data with individual frames of the timestamped video frames according to a common timeframe; and selecting a subset of video frames from the plurality of timestamped video frames based on the selected event.

A method and apparatus for delivering interactive television (ITV) data by using the same TV scan line that also carries closed caption data. The ITV data is inserted into the scan line with CC data by detecting a gap associated with a first CC data unit. If the gap is large enough to contain all of the group of ITV data units then electronically insert the entire group of ITV data units into the gap. If the gap is not large enough to contain the entire group of ITV data units, insert a subset of the entire group of the ITV data units into the gap and continue to the gaps associated with successive CC data units, inserting subsets of the ITV data into subsequent gaps until the entire ITV message has been inserted into the gaps between CC data units.

The invention belongs to the technical field of 3D measurement, and provides a 3D information measuring device, including: an image acquisition device, which is used to collect a group of images of a target object through the relative movement between the collection area of ​​the image collection device and the target object; The acquisition area of ​​the driving image acquisition device and the target object generate relative motion; the acquisition area moving device adopts one of the following two schemes: ① the acquisition area movement device is a rotating shaft device, so that the image acquisition device rotates along a central axis; ② The acquisition area moving device is an optical scanning device, so that when the image acquisition device does not move or rotate, the acquisition area of ​​the image acquisition device and the target will move relative to each other. The invention adopts a monocular camera and a collection area mobile device with a more streamlined structure and a smaller footprint. The rapid transformation of the relative position of the acquisition area and the target object is realized, the image acquisition efficiency is accelerated, and the interference caused by the moving camera is reduced.

The invention belongs to the technical field of communication, and particularly relates to a method for synchronously capturing a short-wave multi-carrier signal with a leader sequence. The method comprises the following steps of: performing power spectrum analysis on a signal in a time domain and a frequency domain simultaneously in a sliding window manner by utilizing leading audio frequency information in the signal, and covering frequency offset of a plurality of positive and negative subcarrier intervals on the frequency domain by a time-frequency sliding window which comprises a plurality of multi-carrier symbols on the time domain, taking the leading sound average signal-to-noise ratio of a plurality of symbols in the time-frequency sliding window as a capture judgment standard; if the average signal-to-noise ratio of the leading sound in the current sliding window length is greater than the capture threshold and the number of symbols with high signal-to-noise ratios is greater than a certain value, it is considered that the capture is successful; meanwhile, the time domain position and the frequency domain position corresponding to the current sliding window are respectively the calculation basis of the initial time offset estimation value and the initial frequency offset estimation value; according to the method, the characteristics of the leading sound signals are fully utilized, multi-symbol time-frequency analysis is combined, normal synchronous capture can still be performed under large frequency offset, and the robustness of synchronous capture is improved.