39results about How to "Improve space reuse" patented technology

Provided are a method of performing contention based channel access by classifying a contention period into a beamformable contention period in which a beamforming is allowed and a non-beamformable contention period in which the beamforming is interrupted so as to resolve an issue regarding channel access occurring due to an introduction of a directional antenna for handling a path loss in a wideband wireless communication system according to an embodiment of the present invention, and a method for maximizing a spatial reuse gain by managing, for each direction, information about a transmission time of a message received from a dispersion device.

The invention relates to a routing method suitable for the static ad hoc formation. Aiming at the special organization structure of the static Ad hoc formation, a centralized topologic control is carried out inside the ad hoc formation; the formations are clustered according to the results of the topologic control; and a new double-frequency multi-stage routing method is adopted so as to ensure the reliable and quick routing establishment and the data transmission inside the formation and among the members inside the formation. The method is characterized in that the method includes the following steps: the topologic control in the formation, the establishment of the formation network structure, the maintenance of the formation network structure, the search of a transmission router, the maintenance of the transmission router, the routing error control and the re-establishment of the router. By adopting the method, the reliable and quick routing establishment and the data transmission in the formation and among the members inside the formation can be realized, the interference in the wireless transmission can be reduced, the network capacity can be further improved, the node service life is prolonged, and the network survival time is increased.

The invention provides a method for implementing an aeronautical Ad hoc network STDMA (Self Organizing Time Division Multiple Access) protocol based on a directional antenna. Through adoption of a directional antenna model, node directional transmission and directional reception, the spatial reuse is enhanced. Meanwhile, a method of combining fixed time slot assignment with dynamic time slot assignment is adopted, namely, the fixed time slot assignment is realized on the basis of a polling strategy, and optimization of dynamic time slot scheduling is realized in combination with an ADS-B system. In the case of emergency demands, reservation of additional time slots is performed, so that time delay of services can be ensured at a certain degree, and an emergency data transmission demand can be met. Through adoption of the method, time slot resources are fully utilized, and the spatial reuse and network throughput are enhanced.

The invention discloses an implement method of power control cognition MAC protocol based on time division multiple access (TDMA). The method comprises the following steps: adopting strict time slot division, finishing time slot allocation among node pairs by a three-way handshake manner, namely, reserving application, reserving confirmation and deciding sending; realizing collision-free transmission in node communication process; and introducing a power control mechanism to improve the reuse rate of cyber space. The method can eliminate problems of multiple channels hiding a send terminal, multiple channels hiding a receiving terminal and multiple channels exposing terminals, and can dramatically decrease the impact on network performance brought by the problem of multiple channels hidingthe send terminal. The simulation result indicates, compared with dynamic spectrum access MAC (DSA-MAC) protocol, the invention can effectively enhance network throughput and decrease access time delay with the increment of network business volume.

The invention discloses a distributed graph coloring link dispatch scheme of a wireless sensor network based on a graph coloring algorithm. According to the scheme, firstly, partial interference information is obtained through packet switching among nodes; secondly, a graph vertex coloring analysis is carried out on a generated localized network conflict graph; thirdly, the conflict-free time slot allocation of a wireless sensor network link is obtained. To improve the coloring success rate, two mechanisms are provided. One mechanism is a broadcast safeguard mechanism for improving the broadcast information delivery rate, and the other mechanism is a conflict processing mechanism for solving the coloring conflict problem. According to the distributed link dispatch scheme, the problems of packet loss, delay and the like caused by multi-hop transmission are solved, and the transmitting energy consumption is reduced. The result of the network simulation shows that the distributed graph coloring link dispatch scheme has the advantages over a conventional link dispatch method on the aspects of energy consumption, the space reusing rate, the packet loss probability and the like.

The invention provides a carrier sensing method based on a dynamic idle channel assessment threshold. According to the method, the existing carrier sensing mechanism is improved, and a CCA (Clear Channel Assessment) threshold is adjusted and an effective range of an NAV (Network Allocation Vector) is controlled according to the channel condition, so that the concurrent transmission in a network is increased and the network throughput is improved. According to the method, the CCA threshold is dynamically computed and adjusted according to the receiving power, so that the spatial reuse of the network can be effectively improved, meanwhile, through carrying an interference margin and a probability of acceptance at a CTS (Clear To Send) group, the range of action of the NAV in the CTS group is effectively controlled, and the spatial reuse is further improved, so that the network throughput is improved.

The invention discloses a method which can realize power control and the device thereof, and a method to manage the neighbor list. Wherein, the device to realize power control includes a transmitting module arranged at the source node to transmit a power transmitting information packet which has the value of the transmitting power, a storage module arranged at the source node and connected with the transmitting module to store the power transmitting information, and a receiving module arranged at the destination node and connected with the transmitting module to receive the information packet. The device also includes a first module arranged at the destination node and connected with the receiving module for obtaining the modification information according to the value of the transmitting power, a second module arranged at the source node and connected with the first module and the storage module for modifying the transmitting power according to the modification information. Adopting the device can save energy and increase the communication channel space reuse degree while at the same time keeps the network a fine connectivity by the nodes in the wireless sensor network.

The invention relates to a transmission control frame method based on dynamic power adjustment which is in the field of wireless local area network transmission technology, wireless self-organized network communication nodes detects around other nodes, and obtains transmission distance communicated with around nodes, a transmitting power table is established communicated with around nodes; then, communications nodes receives around other nodes control frame, and obtains the optimal transmitting power communicated with other nodes through the optimal power formula, transmitting power in the node transmitting power table is updated by the optimal transmitting power; again, when communication nodes sending frame to around nodes, the first judges frame, if the frame is the RTS / CTS control frame, thus the node finds the optimal transmitting power from self-transmitting power table, and sends control the frame; if the frame is data frame, thus sending in accordance with the largest transmission power. The invention improves integral network communication space reuse degree, and increases network integral throughput greatly.

A method in a network node (115) is disclosed. The method comprises allocating (1204) a pool of radio resources for vehicle-to-other (V2x) communication by a plurality of wireless devices (110), and dividing (1208) the allocated pool of radio resources for V2x communication into a plurality of orthogonal sets of radio resources, each set of radio resources having an associated set identifier comprising one of a plurality of positive integers. The method further comprises assigning (1212) one or more radio resource sets to each wireless device among the plurality of wireless devices based at least in part on a radio- compatibility characteristic, and communicating (1216) to each wireless device the assigned set of radio resources to use.

There is provided beam forming using an antenna array. The antenna array is configured to transmit across an angular sector. The angular sector is divided into at least two sub-sectors by respective port weights being applied to respective physical antenna ports of the antenna array. A respective set of virtual antenna ports is determined for each sub-sector. A first set of reference signals for acquiring channel state information on the set of virtual antenna ports is alternatingly transmitted in each one of the at least two sub-sectors.

A method of selecting antenna segments for transmission and / or reception in a MIMO wireless transmission system using sectorized directional antennas, includes the steps of selecting, from an initial set of ranked link antenna patterns, a link antenna pattern having the best average rank, at predetermined time intervals, successively selecting a subset of link antenna patterns having average ranks within a predetermined distance to the best average rank, determining an average link performance of the link antenna patterns selected in the preceding step, determining an average rank of the link antenna patterns, for which the average link performance has been determined in the preceding step, selecting the link antenna pattern having the best average rank, and repeating the process at the next predetermined time interval.

A method performed by a first communication apparatus for transmitting data to a second communication apparatus in a communication channel shared with a communication link including a third communication apparatus, wherein all of the first communication apparatus, the second communication apparatus and the third communication apparatus employing directional transmission, the method comprising: determining there is data to be transmitted to the second communication apparatus; and transmitting the data to the second communication apparatus before listening to the channel.

A method and system for improving spatial reuse in a wireless local area network (WLAN) by per-client dynamic power management. Each access point of the WLAN associates each of its clients with a minimum power level. A central controller of the WLAN generates a schedule for transmission at different power levels, and each access point varies its transmission power level based on the schedule. An access point transmits data packets, at the scheduled transmission power level, to clients associated with a minimum power level that is less than the scheduled power level.

There is provided beam forming using an antenna array configured to transmit across an angular sector. A first set of virtual antenna ports is determined by a mapping of physical antenna ports of the antenna array, the first set of virtual antenna ports defining a beam pattern. A first set of reference signals for acquiring channel state information is transmitted over the first set of virtual antenna ports. Angular information about a wireless transceiver device receiving the transmitted first set of reference signals is acquired. The beam pattern is adapted based on an accuracy of the angular information and / or the angular information itself.

The invention provides an underwater acoustic parallel transmission method based on active time reversal. Spatial weak correlation of channel response between different links caused by complex underwater acoustic multipath propagation is utilized; the space-time focusing of the signal at the receiving position is obtained, the influence of inter-link interference in a parallel transmission scene is effectively suppressed by combining up / down sampling, the spatial multiplexing degree is improved, and the transmitting power of the transmitting node is minimum on the premise of meeting the specific service quality of the receiving node by combining a power control method. According to the method, the broadcast characteristic of an underwater acoustic channel is weakened, and the key effect ofeffectively isolating signal interference between adjacent links in a distributed multi-hop environment is achieved; the up / down sampling method further suppresses inter-link interference and inter-symbol interference, so that the spatial multiplexing degree is further improved. According to the power control method, the transmitting power is saved on the premise that inter-link interference is effectively suppressed, and the method is endowed with effectiveness in an underwater acoustic parallel transmission scene due to the characteristics.

A data communications network includes a ring configured for spatial reuse, such as a resilient packet ring. A first bridge is coupled to the ring and to an end station such as an interworking bridge or router. A second bridge coupled to the ring learns an association between the first bridge and the end station by monitoring packets originated in the network by the end station and sent on the ring by the first bridge. The second bridge learns the association by obtaining an identifier of the first bridge and an address of the end station from received packets. When the second bridge receives packets destined for the end station, the packets are forwarded as broadcast transmissions on the ring if the association between the first bridge and the end station has not yet been learned, and are forwarded as unicast transmissions to the first bridge on the ring if the association between the first bridge and the end station has been learned.

The invention discloses a user clustering method and system based on a large-scale MIMO-NOMA system, and a medium, and the method comprises the following steps: 1, determining a channel matrix H according to a selected channel model, calculating the channel gain of a user, and carrying out the sorting; 2, determining boundary users and confirming an initial cluster head by calculating the channel coherence degree of the users; 3, calculating the channel coherence degree between the cluster head set and the candidate user set, setting a threshold value, selecting all cluster heads, and determining a cluster head set gamma; 4, calculating the channel coherence degree and channel difference between the remaining users and the cluster head set, setting a channel coherence degree threshold value delta 2, and finally determining the user grouping condition. The user clustering algorithm provided by the invention not only is beneficial to eliminating inter-cluster interference and increasing multiplexing gain, but also has better frequency efficiency performance compared with a traditional OMA structure under the same condition.

A method of selecting antenna segments for transmission and / or reception in a MIMO wireless transmission system using sectorized directional antennas, includes the steps of selecting, from an initial set of ranked link antenna patterns, a link antenna pattern having the best average rank, at predetermined time intervals, successively selecting a subset of link antenna patterns having average ranks within a predetermined distance to the best average rank, determining an average link performance of the link antenna patterns selected in the preceding step, determining an average rank of the link antenna patterns, for which the average link performance has been determined in the preceding step, selecting the link antenna pattern having the best average rank, and repeating the process at the next predetermined time interval.

The invention provides an underwater acoustic network reservation multi-access method based on active time reversal, and relates to the technical field of underwater acoustic communication and underwater networks. Multiple access in the data transmission process among nodes, which is applicable to a distributed acoustic network MAC layer, is adopted, so that the transmission conflicts are avoided, the success probability and channel utilization rate of once transmission are substantially improved, and the networking energy consumption is lowered; by means of active TR space-time focusing and the space change characteristic of an underwater acoustic channel, the disadvantages are converted into advantages, the broadcasting characteristics of the underwater acoustic channel is weakened, the signal interference among adjacent links under a distributed multi-hop environment is effectively isolated, and the good transmission concealment and security of the multi-access method are realized by channel broadcasting weakening, so that the space multiplexing is improved, the network throughput is increased, the time delay of the system is shortened, and energy is saved.

Provided are a method of performing contention based channel access by classifying a contention period into a beamformable contention period in which a beamforming is allowed and a non-beamformable contention period in which the beamforming is interrupted so as to resolve an issue regarding channel access occurring due to an introduction of a directional antenna for handling a path loss in a wideband wireless communication system according to an embodiment of the present invention, and a method for maximizing a spatial reuse gain by managing, for each direction, information about a transmission time of a message received from a dispersion device.

The invention relates to a routing method suitable for the static ad hoc formation. Aiming at the special organization structure of the static Ad hoc formation, a centralized topologic control is carried out inside the ad hoc formation; the formations are clustered according to the results of the topologic control; and a new double-frequency multi-stage routing method is adopted so as to ensure the reliable and quick routing establishment and the data transmission inside the formation and among the members inside the formation. The method is characterized in that the method includes the following steps: the topologic control in the formation, the establishment of the formation network structure, the maintenance of the formation network structure, the search of a transmission router, the maintenance of the transmission router, the routing error control and the re-establishment of the router. By adopting the method, the reliable and quick routing establishment and the data transmission in the formation and among the members inside the formation can be realized, the interference in the wireless transmission can be reduced, the network capacity can be further improved, the node service life is prolonged, and the network survival time is increased.

Beamforming using an antenna array configured to transmit across angular sectors is provided. A first set of virtual antenna ports is determined by mapping of physical antenna ports of the antenna array, the first set of virtual antenna ports defining a beam pattern. A first set of reference signals for acquiring channel state information is transmitted through a first set of virtual antenna ports. Angular information related to wireless transceiver devices receiving the transmitted first set of reference signals is obtained. The beam pattern is adapted based on the accuracy of the angular information and / or the angular information itself.

A method performed by a first communication apparatus for transmitting data to a second communication apparatus in a communication channel shared with a communication link including a third communication apparatus, wherein all of the first communication apparatus, the second communication apparatus and the third communication apparatus employing directional transmission, the method comprising: determining there is data to be transmitted to the second communication apparatus; and transmitting the data to the second communication apparatus before listening to the channel.

The invention provides a method for implementing an aeronautical Ad hoc network STDMA (Self Organizing Time Division Multiple Access) protocol based on a directional antenna. Through adoption of a directional antenna model, node directional transmission and directional reception, the spatial reuse is enhanced. Meanwhile, a method of combining fixed time slot assignment with dynamic time slot assignment is adopted, namely, the fixed time slot assignment is realized on the basis of a polling strategy, and optimization of dynamic time slot scheduling is realized in combination with an ADS-B system. In the case of emergency demands, reservation of additional time slots is performed, so that time delay of services can be ensured at a certain degree, and an emergency data transmission demand can be met. Through adoption of the method, time slot resources are fully utilized, and the spatial reuse and network throughput are enhanced.

The invention provides a symmetric carrier elimination optical communication method, a visible light transceiver and a visible light communication terminal, which are used for reducing the alignment difficulty of point-to-point interconnection. According to the symmetric carrier elimination optical communication method, a visible light communication terminal and an opposite terminal are communicated with the same reflecting surface. The method comprises: a visible light communication terminal sending a first visible light signal to a reflecting surface; the visible light communication terminalreceiving the visible light signal and converting into a first target electric signal; wherein the first target electric signal comprises a first receiving signal and a second receiving signal; wherein the first receiving signal is an electric signal which is transmitted to the reflecting surface by the first visible light signal and then received by the visible light communication terminal; wherein the second receiving signal is an electric signal received by the visible light communication terminal after the second visible light signal is transmitted to the reflecting surface; the visible light communication terminal performing channel estimation on the first received signal to obtain an estimated signal; and subtracting the estimation signal from the first target electric signal to obtain an estimation signal of the second receiving signal.

The invention provides a signal monitoring method, system and device and a storage medium, and the method comprises the steps: setting a register in a processor for storing an abnormal signal, and setting a data reading address pointer and a data writing address pointer; setting a timer in a processor, reading a count value of the timer in response to the detected abnormal signal, and storing the count value in the register; storing the state of the abnormal signal to a data write-in address, and moving a data write-in address pointer towards a first direction; and in response to the fact that the communication interval time between the processor and the BMC exceeds a threshold value, using the time for triggering interruption as the time for occurrence of the abnormal data received next time. According to the invention, a CPLD and BMC bidirectional timing mechanism is adopted to record the triggering time of the abnormal signal, so that subsequent maintenance personnel can conveniently locate the cause of the abnormality according to the occurrence time of the abnormality.

A method in a network node (115) is disclosed. The method includes allocating (1204) a pool of radio resources for vehicle-to-other (V2x) communications of a plurality of wireless devices (110), and dividing (1208) the pool of radio resources allocated for V2x communications into a plurality of orthogonal sets of radio resources , each radio resource set has an associated set identifier comprising one of a plurality of positive integers. The method also includes assigning (1212) one or more sets of radio resources to each of the plurality of wireless devices based at least in part on the radio compatibility characteristic, and communicating (1216) the assigned set of radio resources to each wireless device for use.

There is provided beam forming using an antenna array. The antenna array is configured to transmit across an angular sector. The angular sector is divided into at least two sub-sectors by respective port weights being applied to respective physical antenna ports of the antenna array. A respective set of virtual antenna ports is determined for each sub-sector. A first set of reference signals for acquiring channel state information on the set of virtual antenna ports is alternatingly transmitted in each one of the at least two sub-sectors.

The invention provides a carrier sensing method based on a dynamic idle channel assessment threshold. According to the method, the existing carrier sensing mechanism is improved, and a CCA (Clear Channel Assessment) threshold is adjusted and an effective range of an NAV (Network Allocation Vector) is controlled according to the channel condition, so that the concurrent transmission in a network is increased and the network throughput is improved. According to the method, the CCA threshold is dynamically computed and adjusted according to the receiving power, so that the spatial reuse of the network can be effectively improved, meanwhile, through carrying an interference margin and a probability of acceptance at a CTS (Clear To Send) group, the range of action of the NAV in the CTS group is effectively controlled, and the spatial reuse is further improved, so that the network throughput is improved.

The invention discloses a multi-access scheduling method based on a directional antenna, which is characterized in that on the basis of a multi-access protocol of an omnidirectional distributed wireless ad hoc network adopting a reservation mechanism, resource scheduling is carried out by adopting a mode of periodically interacting scheduling information units, and nodes continuously update a local scheduling information linked list through periodic interaction control messages; and when the node performs time slot authorization, selecting an idle time slot or a time slot meeting a multiplexing condition to perform authorization by traversing a local scheduling information linked list, thereby realizing multiplexing of the data time slot. According to the invention, resource scheduling is carried out by periodically interacting scheduling information units. And the nodes continuously update the local scheduling information linked list through periodic interaction control messages. When resource authorization is carried out by an authorization node, authorization can be carried out only by traversing a local scheduling information linked list to select an idle time slot or meeting a multiplexing condition. The multiplexing of data time slots is realized, the spatial multiplexing degree of the distributed wireless ad hoc network is improved, and the network capacity is further improved.