18 results about "Slot synchronization" patented technology

The invention provides a DVB frequency offset estimation method and device, equipment and a storage medium. The method comprises the following steps: acquiring a waveform; performing time slot synchronization on double-speed time domain data received by a digital video broadcast reverse link baseband to obtain synchronized data; and performing frequency offset estimation according to the waveform and the first burst at the synchronization head of the synchronized data. According to the method, adaptive frequency offset estimation is carried out according to the waveform and the first burst at the synchronization head of the synchronized data, and the performance of a satellite communication system is improved.

Described herein are systems and methods for reducing collisions in a wireless network with overlapping basic service sets by synchronizing contention slots among stations (access points or non-access point clients), some of which are out of range, competing for the use of the wireless medium. In some embodiments, the contention slots of competing stations are synchronized by controlling the time of transmission and the time of the spacing between frames to be an integer multiple of the time of a contention slot. In some embodiments, slot boundaries are enforced by controlling guard intervals or by trigger-based uplink communications. In other embodiments, a central network controller, such as a network controller, synchronizes slots when an access point or station joins the wireless network or uses a neighbor discovery protocol among access points. The contention slots are synchronous in all cases throughout the overlapping basic service sets.

Embodiments of the present application provide a user-based fine-grained time slot synchronization method and related device, and relate to the technical field of communication. The method comprises: analyzing whether a data frame received from a first device is a first time slot request frame; if yes, generating a plurality of first time slot occupation description information according to a first target user identifier included in the first time slot request frame and a plurality of saved first time slot mapping information, and sending the first time slot occupation description information in a first time slot response frame to the first device, so that the first device obtains first target time slot mapping information corresponding to the first target user identifier, wherein one first time slot response frame includes a plurality of first time slot occupation description information, and one first time slot occupation description information is used to indicate whether a first target user represented by the first target user identifier occupies a time slot corresponding to the first time slot occupation description information. In this way, the flexibility of time slot synchronization can be improved, and the number of data frames sent in time slot synchronization can be reduced.

An apparatus comprising: at least one processor; and at least one memory, the at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus to at least: transmit an indication of a synchronization signal pattern; wherein the indication of the synchronization signal pattern indicates at least one of: a number of portions of the synchronization signal burst wherein each portion occupies a number of consecutive time slots, a number of consecutive time slots in each portion of the synchronization signal burst, or a slot between adjacent portions of the synchronization signal burst that is not used to transmit any synchronization signal of the synchronization signal burst; and transmitting the synchronization signal at a synchronization signal position indicated by the synchronization signal pattern.

The present invention discloses a multi-hop pipeline propagation method based on TDMA time slot synchronization, comprising the following steps: S1, constructing a TDMA frame format; S2, constructing a local pseudo-transition time mapping table in the uplink receive time slot; S3, constructing a local clock drift trend model based on a bat resonance fitting algorithm; S4, predicting the expected arrival time of the next uplink synchronization based on the model and adjusting the local clock; S5, completing data packet processing operations in the local processing time slot; S6, in the downlink transmit time slot, the node completes service data transmission and appends local clock drift trend model parameters; S7, entering a low-power listening state in the protection sleep time slot, comparing the difference between the feedback model parameters and the model parameters, and updating the model if the difference exceeds a preset tolerance threshold; S8, the node injects Gaussian perturbations into the local clock within a set frame period and regularly updates the model. The present invention uses the bat resonance fitting algorithm and time slot modeling method to achieve multi-hop node autonomous synchronization.

The application discloses a distributed industrial wireless network deterministic transmission scheduling system, which comprises the following modules: a synchronization module for time slot synchronization between nodes; a data transmission module for data transmission between nodes; and a node management module for node deletion and addition management. The application uses distributed negotiation scheduling design, reduces overall energy consumption and delay of the network, and avoids network paralysis caused by failure of a central control node.

This invention discloses a bidirectional communication ranging method based on a room-temperature single-photon detector, belonging to the field of laser communication and ranging technology. The method employs a serial concatenated pulse position modulation coding and bidirectional asynchronous response ranging mechanism, designing a dedicated frame structure including a frame synchronization header, time information, and communication data. The proportion of ranging frames is controlled within the communication bandwidth, achieving integrated communication and ranging functions. At the receiving end, a coarse-fine concatenated time slot synchronization method is used: first, coarse synchronization is achieved by recovering the time slot clock through matched filtering; then, fine synchronization is achieved by compensating for residual time slot offsets based on a maximum likelihood estimation algorithm, significantly improving time slot synchronization accuracy. This invention, operating under room-temperature single-photon detector conditions, eliminates the need for cryogenic cooling equipment, effectively solving the problem of balancing communication rate and ranging accuracy. It significantly improves ranging accuracy and system stability, and is suitable for scenarios sensitive to size and power consumption, such as inter-satellite links and underwater communication.

The invention discloses a distributed time slot synchronization system and method for multi-user full-duplex talkback, and the method comprises the steps: carrying out the initial monitoring, and enabling each talkback device in a talkback system to enter a full-time slot receiving state after the talkback device is started up; time slot preemption: a single intercom device randomly selects an emission time slot in idle time slots according to Poisson distribution when detecting continuous idle time slots, and initiates voice signal transmission; an alignment reference is selected, when only one speaker exists, the time slot of the speaker is taken as a reference, when multiple speakers exist, the talk-back device of each speaker calculates the receiving success rate of the data packets of the talk-back devices of other speakers, and the time slot of the talk-back device with the highest receiving success rate is selected as the reference time slot of the speaker; and time slot alignment and reference updating: performing time slot alignment on each intercom device, and updating the reference time slot of the time slot alignment according to the self condition, thereby realizing multi-person full duplex intercom. All intercom devices in the system are equal and do not depend on a host, the self-healing performance and robustness of the system are higher, and the cost is reduced.

The invention relates to a grooving machine capable of synchronously carrying out double-roller transverse pressing grooving, and belongs to the technical field of carton processing equipment. The grooving machine comprises a paper feeding mechanism, an initial pre-pressing mechanism, a pre-pressing mechanism, a transverse line pressing mechanism, a transition transmission mechanism, a grooving mechanism, a main motor, a vertical line pressing adjusting mechanism and a PLC control system. The main motor drives all the roller bodies to operate synchronously through the gear transmission system, and continuous conveying of paperboards is achieved. The vertical line pressing adjusting mechanism adjusts the positions of the pre-pressing wheel and the line pressing groove wheel in a linkage mode so as to set the height of the carton. A lower roller of a grooving transverse pressing angle knife of the grooving mechanism is independently controlled by a servo motor, grooving and transverse pressing can be synchronously completed in an accelerated mode when the paperboard is in place, then speed reduction and resetting are conducted, and high-precision intermittent machining is achieved. The machine supports processing of paperboards with different thicknesses and sizes, has the advantages of high-speed production, high precision, high universality, high automation degree and the like, realizes synchronization of line pressing and slotting, synchronously completes transverse indentation and slotting in one-time feeding, and eliminates process intervals.

The application discloses a lightweight asynchronous Byzantine fault-tolerant consensus method, which comprises a message distribution stage, a time slot synchronization stage and an asynchronous negotiation stage. In the message distribution stage, a sender node broadcasts a message of a running instance to other nodes, and sequentially delivers the message broadcasted by each node; in the time slot synchronization stage, the sender node broadcasts the latest progress of the current broadcast to other nodes; in the asynchronous negotiation stage, the sender node votes on the delivered message, and sequentially outputs a message set. By using the application, all nodes can safely and efficiently ensure the same view. The application can be widely applied in the field of blockchains.

Embodiments of the present application provide a time slot information acquisition method and device, network equipment and storage medium, and relate to the technical field of communication. The method is applied to a first node, and includes: sending a time slot detection packet on a forwarding path of a deterministic flow, the forwarding path including the first node and multiple forwarding nodes; recording time slot information of the first node processing the time slot detection packet, and receiving a time slot synchronization packet sent by each forwarding node on the forwarding path, the time slot synchronization packet including time slot information of the forwarding node processing the time slot detection packet; and calculating a time slot deviation of each node processing the time slot detection packet respectively by using the time slot information of the first node processing the time slot detection packet and the time slot information of each forwarding node processing the time slot detection packet, the time slot deviation being a delay of the node processing the time slot detection packet internally. The time slot information of each node can be acquired efficiently, and the delay of each node processing the time slot detection packet internally can be determined.

The present disclosure relates to the technical field of computers, and particularly provides a data synchronization method, device, system, equipment, medium and product. In the present disclosure, when a primary and backup data synchronization task is started, a first replication slot is determined from a configuration center, the first replication slot is used to record the progress of data synchronization, the configuration center is used to dynamically update and listen to slot information in the first replication slot; the slot information in the first replication slot is updated to the configuration center; when a new transaction is confirmed to be submitted, the current physical log is synchronized to a backup database of a first cluster; when a current log position of the backup database is received, the updated slot information is sent to the backup database. By modifying the transaction submission process, the decoupled synchronization of the slot information of the replication slot and the physical log is realized. Without modifying the corresponding logic of the physical log, the replication slot synchronization in the database one-primary-multiple-backup scenario is realized, and the efficiency of data synchronization is improved.

The invention discloses an AIS (Automatic Identification System) multi-level time slot synchronization method, relates to the technical field of time slot synchronization, and aims to solve the problems of poor synchronization effect in a synchronization process and wrong verification after synchronization. By monitoring the communication process of the AIS equipment in each time slot in real time, the communication abnormal condition can be found in time, the time slot synchronization signal frequency is estimated, and the local clock frequency is adjusted accordingly, so that the system can adapt to the change of the signal frequency and is suitable for various different application scenes and signal environments, and in the feature information extraction process, the feature information extraction efficiency is improved. The initial timestamp is determined by detecting an amplitude abrupt change point or the initial position of a specific synchronous code pattern, the center frequency is determined through frequency domain analysis, and the initial phase value is combined with frequency information calculation, so that the accuracy of feature information extraction is improved, the local clock frequency is dynamically adjusted by using a phase-locked loop, and the accuracy of feature information extraction is improved. And the local clock frequency can be automatically adjusted to a state close to the time slot synchronization signal frequency according to the calculated frequency deviation.

The application discloses a hybrid random access method and device in a satellite Internet of Things scene, and the method comprises the following steps: a terminal of a sending end receives a synchronization signal, and frame and time slot synchronization is completed; according to the sending requirements of each terminal, it is determined that each terminal is in a non-spread spectrum mode or a spread spectrum mode, wherein the terminal of the sending end comprises a non-spread spectrum terminal and a spread spectrum terminal; a non-spread spectrum data packet is obtained by carrier modulation on a non-spread spectrum terminal signal, and a spread spectrum data packet is obtained by spread spectrum modulation on a spread spectrum terminal signal; the non-spread spectrum terminal randomly sends the modulated non-spread spectrum data packet by selecting a channel and a time slot, and the spread spectrum terminal randomly sends the modulated spread spectrum data packet by selecting a channel and a time slot. The hybrid superposition of two traditional random access modes, i.e. a non-spread spectrum random access mode and a spread spectrum random access mode, in the same system is realized, the system throughput can be improved, the business requirements of various terminals in an actual scene can be met, and the method is suitable for a working scene of massive terminal access of a satellite Internet of Things and the like.

Disclosed herein is a method and apparatus for synchronizing timeslots in a wireless LAN system. The timeslot synchronization method includes: setting, by a first node, a timeslot synchronization reference based on a time synchronization function (TSF) value, followed by transmitting information about a reference of synchronization to a second node; and setting, by the second node, a timeslot synchronization reference based on a TSF value corresponding to the reference of synchronization based on the information transmitted from the first node.

The invention provides a communication and inductance integrated access method, device and equipment. The method comprises the following steps: in a (T-1) th transmission period, determining a first channel used for sending a communication signal in a Tth transmission period; in the first stage of the Tth transmission period, receiving time slot synchronization information and ISAC channel occupation information of other unmanned aerial vehicle nodes, and recording the ISAC channel occupation information to the NAV; according to the information recorded in the NAV, determining a second channel used for sending the sensing signal in the Tth transmission period; in the second stage of the Tth transmission period, the communication signal is sent through the first channel, and the sensing signal is sent through the second channel; each transmission period comprises a first stage and a second stage, and the first stage is used for transmitting ISAC channel occupation information; and the second stage is used for transmitting communication signals and sensing signals. According to the invention, the communication and perception integrated design of the unmanned aerial vehicle network is realized, and directional communication and multiple perception requirements can be met.

The application discloses a UAV ad hoc network communication method in a signal shielding environment, and belongs to the technical field of UAV communication. The technical problem to be solved is that the existing UAV ad hoc network adopts a passive response architecture in a serious signal shielding environment, and problems such as frequent link interruption, mixed communication transmission conflict, route switching lag, imbalance between endurance and communication stability, and communication island formed in a continuous shielding scene are prone to occur. Technical solution points are as follows: firstly, a three-dimensional grid map and a shielding probability map are constructed by a scout UAV, and the network is synchronized; secondly, adaptive clustering networking is carried out based on the shielding probability, and TDMA time slot synchronization is adopted for dual-frequency communication; thirdly, multi-route dynamic switching is pre-calculated; fourthly, the transmission power and the sleep level are dynamically adjusted according to the shielding probability; fifthly, a virtual relay point position library is pre-generated, and a fault self-recovery mechanism is realized through a route switching and node replacement dual-track mechanism; and finally, the map is updated in real time, the nodes are dynamically connected to and disconnected from the network, and stable communication of the UAV ad hoc network in a strong shielding environment is ensured.