74 results about "Time division multiple access" patented technology

The invention discloses a paired time division multiple access method and a paired time division multiple access device in a high dynamic scene. The method comprises the following steps of: mapping each link request into a vertex of a conflict graph; according to a primary conflict and secondary conflict judgment rule, adding undirected edges for vertex pairs with conflicts, and constructing a communication conflict graph; a TDPA time slot allocation problem is formalized into a minimum vertex coloring problem of a communication conflict graph; calculating to obtain a neighborhood cardinal number of each vertex through a global greedy coloring algorithm; carrying out descending sorting on the vertexes according to a neighborhood cardinal number; a minimum positive integer which is not used by a neighborhood vertex is distributed to each vertex in sequence to serve as a time slot, and an initial scheduling baseline is generated; updating the communication conflict graph based on the generated initial scheduling baseline and the current topology change information, and identifying failure vertexes; and re-coloring the failure vertexes through an incremental greedy coloring algorithm to obtain a new scheduling scheme. According to the invention, the problems of low channel utilization rate, poor real-time response, insufficient dynamic adaptability and the like in the prior art are solved.

The application discloses a time slot scheduling method of an underwater dynamic multi-hop distribution network based on a time division multiple access protocol, relates to the field of underwater acoustic communication, and is aimed at the underwater multi-hop distribution network, improves the traditional static time slot allocation based on the TDMA protocol, designs a data packet frame structure, comprehensively considers transmission time delays among underwater nodes, dynamically adjusts time slots allocated to the underwater nodes based on the maximum transmission time delay, considers a dynamic node random access condition, and realizes the design of the time slot scheduling method of the underwater dynamic multi-hop distribution network.Compared with the traditional static time slot allocation method, the method can effectively improve the overall throughput of the network and optimize the network operation efficiency.

The invention discloses a relative navigation method and system suitable for measurement asynchronization and communication delay processing, and relates to the field of navigation. The method solves the problems of measurement asynchronization, communication delay and the like of an existing measurement sharing relative navigation method in practical application. The method comprises the following steps: establishing a total error state equation of a relative navigation system for nodes in a cluster; establishing a multi-source measurement equation of a relative navigation system for the nodes in the cluster; based on a time division multiple access in-turn broadcast type communication mechanism, information data packets are shared by each node in the cluster; constructing a time updating equation and a measurement updating equation, and performing filter time updating and measurement updating; carrying out inertial navigation position extrapolation aiming at measurement asynchronization and communication delay to realize accurate alignment of measurement information containing lagging and an inertial navigation position in time; correcting the error feedback and outputting a relative navigation result. The method is also suitable for the application fields of relative navigation algorithms for measuring asynchronization and communication delay processing and the like.

The application provides a kind of unmanned area overhead transmission line network coverage method, along the line deployment multiple as intelligent spacer intelligent network node, node uses modular hot plug structure, equipped with super capacitor and solid-state battery hybrid energy storage system;Through LoRa communication to build distributed wireless mesh ad hoc network, combined with TDMA time division multiple access and AODV adaptive routing protocol;Utilize the power supply of at least two different principle of multi-source fusion self-powered module power supply;Node collects line monitoring data and carries out edge computing processing, and the processed data is transmitted through multi-hop relay transmission of ad hoc network, and then transmitted to the center master station through the main and standby dual-link redundant transmission architecture.The application can realize long-term stable self-power supply and reliable communication of unmanned transmission line, improve the real-time performance of monitoring data transmission and network invulnerability.

The application relates to the technical field of underwater acoustic communication, and discloses a method and system for dynamically allocating resources of an underwater voice communication system. The method comprises the following steps: setting a multi-user priority strategy according to a formation modular grouping; adopting a hybrid access mechanism of fusion of time division multiple access and carrier sense multiple access / collision avoidance, dividing communication channels into inter-group time slots and intra-group time slots, and competing for access to idle sub-carrier clusters in the time slots through a CSMA / CA mechanism; predicting a future state of an underwater acoustic channel; based on the predicted future state, adaptively switching a modulation and coding scheme according to a preset signal-to-noise ratio threshold; distributing sub-carrier bands to users with the largest channel gain based on a channel gain matrix; and combining the multi-user priority strategy, the hybrid access mechanism and the modulation and coding scheme to jointly optimize and distribute sub-carriers, bit loading and transmission power. Through dynamic resource allocation and adaptive transmission optimization, the application effectively improves the resource utilization rate and transmission quality of underwater voice communication.

A coherent transmitter (100, 200) for use in a time division multiple access (TDMA) system is operated in multiple states to enable coherent burst transmission. In an OFF state, the transmitter (100, 200) generates a dummy laser output (fd) from either a dummy laser (102) or an active laser (52) tuned to a dummy frequency different from an active frequency (fa), thereby maintaining thermal and bias stability without adding excess power on an upstream channel (22). In an ON state, the active laser (52) produces an active laser output (fa) that is modulated by a quad-parallel Mach-Zehnder (QPMZ) modulator (60) to transmit data. A thermoelectric cooler (TEC) (58) stabilizes laser temperatures, and a variable optical attenuator (VOA) (54) controls output power. The transmitter (100, 200) is suitable for an optical network unit (ONU) (14) in a passive optical network (PON) (10) communicating with an optical line terminal (OLT) (12).

The application relates to a battery data transmission method and system based on dynamic priority preemption time slots, which comprises the following steps: calculating the dynamic priority of a distributed node according to the data urgency, historical channel quality and basic priority of the distributed node; pre-empting the battery data transmission time slot according to the dynamic priority to perform battery data transmission; and performing a two-stage retransmission strategy to retransmit the battery data when the data transmission fails. The application breaks through the limitation of the fixed time slot allocation of the traditional time division multiple access communication strategy and adapts to the burst communication demand; when the wireless center node based on dynamic priority preemption performs time slot allocation and battery data retransmission, the communication conflict and real-time contradiction in the dense node scene can be effectively solved through software, the reliability, real-time performance and expandability of the system are significantly improved, and the application is suitable for intelligent battery system, electric vehicle, energy storage power station and other high-performance wireless center node application scenes.

The invention relates to an aviation mobile communication method and system based on time division multiple access, belongs to the technical field of satellite communication, and solves the technical problem of low communication quality between a satellite ground station and a mobile communication terminal. Comprising the following steps: in a communication time slot allocated to aviation mobile communication terminals, each aviation mobile communication terminal dispersedly inserts each unique code in a unique code original sequence for auxiliary synchronization into a to-be-sent information code element to construct and obtain a burst signal, and sends the burst signal based on the current sending power; transparently forwarding the burst signal to a satellite ground station by using a satellite transponder; and the satellite ground station extracts the scattered unique codes from the received burst signals, and synchronizes and demodulates the burst signals based on the unique codes to recover the information code elements. And the communication quality between the aviation mobile communication terminal and the satellite ground station is improved.

The invention discloses a Wi-Fi soft scheduling system based on a TSF synchronization token bucket, a communication method, computer equipment and a medium. The system comprises a high-precision TSF synchronization module, a TSF synchronization token bucket gating module and a driving layer scheduling injection and conflict protection module. The high-precision TSF synchronization module is used for providing a uniform time reference with microsecond-level precision and processing system-level errors; the TSF synchronization token bucket gating module is used for realizing time slot scheduling of pseudo TDMA through double constraints of time and capacity, and controlling the authority of a data packet to enter an MAC (Media Access Control) layer; and the driving layer scheduling injection and conflict protection module is used for realizing low-delay transmission injection of the authorization data packet and processing the damage of the competition conflict of the MAC layer to the scheduling certainty through a time slot conflict isolation mechanism. According to the invention, accurate soft control of a data packet transmission time sequence can be realized on a kernel driving layer of an operating system, so that a deterministic time division multiple access effect is simulated on a channel.

A node of a first TDMA network, such as a link 16 network, uses a first receiver to participate in the first network, while using a second receiver to detect and report a second TDMA network, which is not synchronized with the first network, by listening for a characteristic message from the second TDMA network. The timing error between the networks can be estimated from the received message timing. Upon detection, the node can join the second network and / or request updated timing information from the second network. In embodiments where timeslot-specific TRANSEC filters are required, the node selects a TRANSEC filter for a timeslot that is further in the future than an estimated timing error bound. The first and second networks can implement the same network protocol and architecture, differing only due to the timing offset between their network timing references, as would be the case for a split network.

The application relates to the technical field of wireless communication, and discloses a multi-standard wireless intercom system fusion communication method, which comprises the following steps: S1. constructing a multi-standard wireless intercom system; S2. constructing a dynamic time slot division model based on time division multiple access (TDMA) technology, and dividing a time axis into a frame structure comprising fixed guarantee time slots and dynamically allocated time slots; S3. calculating the required time slots of each standard by using an adaptive signal mapping algorithm; constructing a synchronization mechanism to realize microsecond-level clock synchronization; S4. a resource allocation is performed by an intelligent scheduling platform according to an enhanced comprehensive communication demand index; and S5. data transmission and processing are realized according to the resource allocation; through time slot division based on the TDMA technology, signal mapping and the synchronization mechanism, the compatibility of the multi-standard wireless intercom system is realized, so that wireless intercom terminals of different standards can communicate in the same system, and the universality and expansibility of the system are improved.

Disclosed herein is a method performed by a sharing access point (AP) to be able to receive a transmission opportunity (TXOP) return frame during coordinated time division multiple access. The method includes providing a temporary channel access parameter set (TCAPS) to a station (STA) associated with the sharing AP, wherein the TCAPS includes a duration parameter indicating a duration for which the STA is to apply the TCAPS, wherein the duration is sufficiently long to encompass a portion of a TXOP that is to be allocated to a shared AP. The method further includes performing a frame exchange with the STA that causes the STA to apply the TCAPS for the duration, transmitting a TXOP sharing frame to the shared AP to allocate the portion of the TXOP to the shared AP, and receiving the TXOP return frame from the shared AP.

A method of operating a coherent transmitter in a time division multiple access (TDMA) system includes operating in an OFF state while the coherent transmitter is not assigned to transmit data in the TDMA system, wherein operating in the OFF state comprises generating a laser output having a dummy frequency different from an active frequency used to transmit data in the TDMA system; and operating in an ON state while the coherent transmitter is assigned to transmit data in the TDMA system, wherein operating in the ON state comprises generating an active laser output having the active frequency and modulating the active laser output using a modulator. Advantageously, the coherent transmitter can be used at an optical network unit (ONU) in a coherent passive optical network (CPON).

Radar systems and methods for generating mixed signal chirps are provided. An example radar system includes a set of transmitters including a plurality of subsets of transmitters; and a processor coupled to the set of transmitters. In operation, the processor applies a beamforming operation on outputs of transmitters within each subset of transmitters, in which a plurality of beamforming operations are respectively applied to the plurality of subsets of transmitters; applies a first multiple input-multiple output (MIMO) scheme to the subsets of transmitters; and applies a second MIMO scheme to the subsets of transmitters that share a common transmitter. The first MIMO scheme may be Doppler division multiple access (DDMA), and the second MIMO scheme may be one of time division multiple access (TDMA) and frequency division multiple access (FDMA).

The invention discloses an unmanned cluster hybrid access method and system based on statistical priority and time division scheduling fusion. The method comprises the following steps: step 1, constructing a three-stage macroscopic superframe framework of'beacon section-competition section-scheduling section 'on a time domain, introducing a'cyclic micro-frame' mechanism into a scheduling section TDMA (Time Division Multiple Access), discretizing the interior of a micro-frame into a two-dimensional orthogonal time-frequency resource matrix containing a plurality of frequency bands and time slots, and obtaining three resource attributes; step 2, rapidly obtaining the coordinates of the exclusive resources, synchronizing the use state of the resources to the whole network, and providing a global view; 3, constructing a global three-dimensional load view; 4, performing microscopic time slot level intervention on the local nodes with extremely unbalanced flow; 5, reallocation of macroscopic space-time resources is achieved by adjusting the boundaries of the two, and abnormal self-healing under high dynamic is achieved; and step 6, outputting an optimal access threshold value for the whole network through cross-layer calculation and dynamic optimization. According to the method, the high-dynamic concurrence requirement of the multi-stage tidal service is met.

Disclosed herein is a method performed by a wireless device to poll candidate shared APs regarding participation in coordinated time division multiple access (c-TDMA). The method includes transmitting a first control frame to poll candidate shared APs regarding participation in the c-TDMA, wherein the first control frame includes an indication of a primary traffic priority level of traffic to be transmitted during the c-TDMA, receiving, from one or more candidate shared APs as a response to the first control frame, one or more first response frames indicating that the one or more candidate shared APs are interested in participating in the c-TDMA, and selecting one of the one or more candidate shared APs that responded to the first control frame to participate in the c-TDMA based on information included in the one or more first response frames received from the one or more candidate shared APs.

An apparatus for an access point (AP) includes memory and processing circuitry coupled to the memory. The processing circuitry is configured to contend for a wireless medium to obtain a transmission opportunity (TxOP). The processing circuitry is configured to, in response to determining that fairness rules are to be applied during the TxOP, use coordinated time division multiple access (C-TDMA) during the TxOP with applying the fairness rules. The processing circuitry is configured to, in response to determining that the fairness rules are not to be applied during the TxOP, use the C-TDMA during the TxOP without applying the fairness rules. The processing circuitry is configured to maintain a shared-allocation counter per access category (AC), update the shared-allocation counter based on a duration of an allocation and an AC, truncate a TxOP limit, distribute an aggregate truncation, redraw backoff, reset or decrement the shared-allocation counter, refuse a further shared allocation, and enforce a limit on consecutive TxOPs.

A system comprises one or more sensor devices for subcutaneous electroencephalography where each sensor device includes a flexible biocompatible polymer sensor strip adapted to be inserted into a cranial subdermal space and including a plurality of electrodes. The strip includes a microchip responsive to each of the electrodes and comprising a multi-channel integrated circuit system-on-chip with a wireless transceiver, a low-noise neural amplifier, a unique network address, and RF energy harvesting microcircuits. In one embodiment, the sensor strip is no more than about 1 mm wide, at least about 5 cm long, and no more than about 300 μm thick. An external transceiver is disposed on the exterior of the subject's skin near one or more sensor devices in secure wireless communication with the respective wireless transceivers comprised in the sensor devices microchips. The system is configured to communicate using a network communication protocol, such as time division multiple access or code division multiple access.

The invention provides a reliable multi-center relative navigation method applicable to limited communication resources, and belongs to the technical field of navigation. The problems that an existing relative navigation method based on measurement sharing is large in communication burden and affected by packet loss are solved. The method comprises the following steps: establishing a total error state model; establishing a multi-source measurement model; designing an indirect TOA measurement sharing strategy; designing a data link communication mechanism and a data packet format based on time division multiple access in-turn broadcast; performing packet loss check based on the shared broadcast serial number; time updating is carried out in each filtering period, a partial updating strategy is adopted when relative measurement is received, and only sub-states related to current measurement are updated; when barometric altimeter measurement is obtained, an absolute state subspace is extracted and obtained, an absolute measurement part is updated and mapped back to an original state space, and relative navigation results such as relative positions of all unmanned aerial vehicles in a relative coordinate system are obtained through calculation. The method is used in the large-range detection field.

The invention discloses a nonlinear dynamic scheduling communication method for a maritime distress and safety system, and the method comprises the following steps: S1, maintaining the state of a shore-based station of a whole network, and constructing and updating an interference graph based on a physical propagation model; s2, a dynamic scheduler based on a heuristic algorithm calculates nonlinear dynamic priorities for communication requests of various message types; and S3, allocating resources in real time according to the calculated nonlinear dynamic priority, converting a resource allocation problem into solving a maximum weighted independent set, and generating a TDMA time slot allocation scheme of each frame based on an approximate MWIS algorithm. According to the method, the core problems of low spectrum resource utilization efficiency, high service response delay, difficulty in considering high-reliability safe communication and dynamic service load adaptability and the like caused by the adoption of a static time division multiple access scheduling mechanism in an existing maritime communication system can be solved.

The invention discloses a burst mode communication system, which may include one or more channels. Each channel is configured to receive a burst data stream transmitted according to a clock signal and recover the clock signal. The channel can receive a first burst data stream and a second burst data stream in two adjacent clock periods of a clock signal, convert the first burst data stream into a first pulse signal and convert the second burst data stream into a second pulse signal. The channel may recover the clock signal by detecting a time interval between rising edges of the first pulse signal and the second pulse signal. The burst data streams are different signals and are transmitted to a burst mode communication system in a time division multiple access (TDMA) scheme. And a clock recovery circuit is also arranged in the channel and is used for recovering a clock signal.

This operation method of a STA in a wireless LAN system may comprise the steps of: a first STA acquiring a TXOP; the first STA transmitting a polling frame in the TXOP on the basis of Co-TDMA, and receiving a response frame for the polling frame; transmitting an allocation frame after receiving the response frame for the polling frame, and receiving a response frame for the allocation frame; and sharing, with a second STA, an allocated duration in the TXOP.

This invention belongs to the field of power system communication technology and discloses a method and related apparatus for optimizing power wireless local area network communication. The terminal acquires attribute reporting data and reports it to the wireless access point in the control time slot of the current superframe using a superframe-based dynamic time division multiple access mechanism. The wireless access point generates data time slot allocation information and physical layer parameter configuration information based on the attribute reporting data and sends it in the beacon frame of the next superframe. The terminal encodes data according to the configuration information and transmits it in the designated data time slot. The wireless access point receives the data. By jointly reporting service type, data volume, service quality level, and channel state information to the wireless access point, a complete decision-making basis is provided for cross-layer collaborative scheduling. This enables dynamic time slot scheduling of the media access control layer and adaptive configuration of carrier parameters and preamble sequences of the physical layer, effectively overcoming the problems of fixed resource allocation being unable to adapt to the dynamic needs of differentiated services and low resource utilization efficiency caused by independent optimization of two layers.

There is a method and a device arranged to perform the method. The method comprises transmitting, by a first access point (AP), to a second AP and during a transmit opportunity (TXOP) obtained by the first AP, a first frame indicating a first duration within the TXOP allocated to the second AP; receiving, by the first AP from the second AP and during the first duration, a trigger frame addressed to a first station (STA); receiving, by the first AP from the second AP and during the first duration, a second frame indicating a return of the first duration by the second AP to the first AP; and after receiving the trigger frame and the second frame, transmitting, by the first AP to the second STA, a third frame for resetting a basic network allocation vector (NAV) of the second STA.

The invention relates to the technical field of industrial process control and data acquisition, and particularly discloses a transformer copper strip production process data real-time monitoring and wireless transmission system which comprises a data acquisition and edge processing layer, a deterministic wireless transmission layer and a centralized analysis and display layer. The data acquisition and edge processing layer acquires and preprocesses production data in real time; the deterministic wireless transmission layer constructs a low-delay and high-reliability wireless transmission channel based on a time division multiple access and frequency division multiplexing mechanism; and the centralized analysis and display layer stores, analyzes and visualizes the data. By means of the scheme, millisecond-level and deterministic wireless transmission and omnibearing intelligent monitoring of data in the production process are achieved, and the production reliability and the intelligent level are improved.

The application discloses a kind of intelligent running state management system and method of bluetooth MESH communication module, belong to communication technical field, to solve the problem that existing bluetooth MESH network management and control scheme cannot generate accurate whole network state snapshot, cause network topology research and judge distortion, load evaluation error and fault positioning failure, intelligent running state management method of bluetooth MESH communication module is based on whole network unified time reference, using native deterministic time division multiple access scheduling architecture to allocate microsecond level reporting time slot for bluetooth MESH module, through three-target collaborative optimization algorithm dynamically adjusts scheduling parameter, relies on snapshot aggregation model to generate the whole network state snapshot of same time node, finally realizes microsecond level synchronization, zero conflict report, achieves the uncompromising balance of low power consumption, synchronization accuracy and channel unobstructed, the present application can dynamically adapt network state adjustment time slot parameter, module wake-up strategy and channel allocation scheme, synchronously realizes three major goals of low power consumption, high synchronization accuracy and channel unobstructed.

The invention relates to the technical field of time synchronization, and relates to a simplified time synchronization method and system suitable for a TDMA (Time Division Multiple Access) system, and the method comprises the steps: responding to a synchronization message sent by a master node to a slave node, obtaining a local timestamp of the master node at the current moment, and recording the local timestamp as a master node timestamp, obtaining a timestamp of the slave node at the current moment and recording the timestamp as a slave node timestamp; calculating a first increment and a second increment according to the timestamps of the main node at a plurality of continuous moments; in response to the situation that the absolute value of the difference between the first increment and the second increment is greater than a preset threshold value, calculating a correction coefficient, and correcting the unit accumulated step length of the slave node; and iteration is carried out, and iteration is stopped when the absolute value of the difference between the first increment and the second increment is smaller than or equal to a preset threshold value. According to the invention, the time synchronization meeting the TDMA communication requirement is realized through calculation and compensation, and the material cost of the system is obviously reduced. According to the invention, the time synchronization process is more stable and controllable.

To increase the chances of accepting a handover request for a wideband call in a cordless communication device in which both a normal band call and a wideband call can be used between a handset and a base unit. [Solution] A plurality of cordless communication devices, each consisting of a base unit and one or more handset units, are connected to a main unit, and the base units and handset units are wirelessly connected using time division multiple access / time division duplex. When a base unit at the destination receives a handover request for a wideband call from a handset unit and there is no available space for a wideband call but there is available space for a normal band call, the base unit at the destination sends a request to change the wideband call to a normal band call via the main unit to the base unit at the source of the call, changing the wideband call of the handset unit that sent the handover request to a normal band call. The base unit at the destination allows the handover of the handset unit that has been changed from a wideband call to a normal band call.

A system and method for communicating data comprises a group of radios intercommunicating data through a channel using a time division multiple access having a plurality of timeslots. The system further comprises a first radio of the group of radios selecting a data communication selection, said first radio communicating a request control signal to a leader radio of the group of radios. When a request control acknowledge signal is received from a leader radio at the first radio, suspending time division multiple access intercommunicating data within the group of radios using the plurality of timeslots and communicating data through the channel.