247results about How to "Improve channel utilization" patented technology

A method called the evolvable interference management (EIM) method is disclosed in this patent for avoiding interference and collision and increasing network throughput and energy efficiency in wireless networks. EIM employs sensitive CSMA / CA, patching approaches, interference engineering, differentiated multichannel, detached dialogues, and / or spread spectrum techniques to solve the interference and QoS problems. EIM-based protocols can considerably increase network throughput and QoS differentiation capability as compared to IEEE 802.11e in multihop networking environments. Due to the improvements achievable by EIM, the techniques and mechanisms presented in this application may be applied to obtain an extension to IEEE 802.11 to better support differentiated service and power control in ad hoc networks and multihop wireless LANs. New protocols may also be designed based on EIM.

The invention provides an unlicensed spectrum-based data transmission method and device. The unlicensed spectrum-based data transmission method includes the following steps that: an uplink scheduling command transmitted by a base station is received; frequency resources on an unlicensed spectrum which are allocated for a terminal by the base station are determined; whether a channel on the frequency resources is idle is detected; and when it is detected that the channel on the frequency resources is idle, the channel on the frequency resources is continuously occupied to transmit uplink data to the base station. With the unlicensed spectrum-based data transmission method provided by the technical schemes of the invention adopted, the channel of the unlicensed spectrum is continuously occupied to transmit the uplink data when it is detected that the channel of the unlicensed spectrum is idle, and therefore, detection time of the channel of the unlicensed spectrum can be decreased, and the utilization rate of the channel of the unlicensed spectrum in an uplink transmission process can be improved for the terminal, and the transmission efficiency of the uplink data can be also improved.

The invention discloses an adaptive error control method for source channel coding combined optimization, which is characterized in that the source coding output code streams are classified to the following three grades according to the significance: significance, secondary significance and non-significance; and during the channel coding process, the source code streams of the three graders undergo the adaptive unequal error protection by means of variable-velocity forward error control / hybrid automatic repeat request (FEC / HARQ), so as to allow the transmission rate and the channel coding rate of the source code streams to be adjusted adaptively according to the time-varying fading characteristics of the wireless channel, thereby optimizing the transmission quality of the source code streams and improving the transmission efficiency and the channel utilization rate of the whole system. The method comprises the six steps, overcomes the problems of contradiction and resource waste caused by the independent coding of the source and the channel in the prior communication system, achieves the effect of adaptive combined optimization of the source code stream transmission rate and the channel coding rate based on the time-varying fading characteristics of channel, and has good application prospects.

The invention relates to a reliable data interaction method based on an RS-422 serial bus technique, and with the combination of continuous auto repeat request (Auto Repeat request ARQ) protocol, discloses a novel data interaction and verification method based on the RS-422 serial bus technique. A host computer and a lower computer have a response mechanism and repeat frame verification, and moreover the host computer can continuously transmit a plurality of data frames before receiving a response frame transmitted from the lower computer, copies of the data frames can be stored in transmitting buffer when the data frames are transmitted, and corresponding data frame copies in the buffer can be deleted after the host computer receives the response frame. Until a certain number of data frames which do not receive the response frames are accumulated, the host computer stops to retransmit the data frame copies in the buffer. The utilization rate and the communication speed of a channel can be greatly increased. Aiming at the characteristics of an embedded system, information type recognition codes are added into the data frames for communication of the host computer and the lower computer, so that communication of multiple time sequences, parameters and task instructions of the embedded system can be achieved simultaneously.

In the invention, when a service packet needs to be transmitted, the follow steps will be executed: according to the saved and maintained channel usage list, the sending node selects a collision-free service channel; the RTS / CTS packet transmitted on first public channel between the sending node and receiving node realizes the handshake; the sending node transmits the service packet on said selected service channel; after successfully receiving the service packet, the receiving node replays the ACK packet on the second public channel.

The invention discloses a pilot synchronization channel structure for mobile communication systems. The channel structure includes a pilot channel overlapping a synchronization channel (SCH), defined in the wideband code division multiple access (WCDMA) protocol. Each frame of the pilot channel consists of plural time slots. Each time slot is packed with pre-selected pilot symbols, after spread spectrum and scrambling. The overlap can be defined as search code of one symbol length with pilot signal of m−1 symbols length by intermittent overlap. The overlap can also be defined as search code of one symbol length with pilot signal of m symbols length by continuous overlap. The invention combines organically both CDMA 2000 and WCDMA standards to provide better pilot and synchronization functions.

A method for increasing channel utilization in a video broadcast system includes receiving, at a head-end, a request for a video program from one of a plurality of subscriber stations. Determining whether the requested video program is associated with a first subset of channels representing broadcasted channels having a first subscriber viewership level greater than a threshold level, a second subset of channels representing broadcasted channels having a second subscriber viewership level less than the threshold level, and a third subset of channels representing on-demand channels having a third subscriber viewership. The first subset of broadcast channels is substantially continuously transmitted. The second subset of broadcast channels is transmitted based upon channel availability and programming assignments. The third subset of on-demand channels are transmitted from the head-end to at least one of the plurality of subscriber stations upon assigning video programming corresponding to the requesting subscriber station.

The invention discloses a multi-beam ad hoc network channel access control method, aiming at providing an access control method which has a high channel utilization rate and can improve the network performance. The method of the invention is implemented through the following technical scheme: for a distributed multi-beam scene, combining the characteristics of multi-beams, utilizing the broadcastchannel characteristics of an omni-directional network and the high bandwidth and high directivity characteristics of a directional network, using the short message protocol interaction between nodes,and assisting to complete the high-rate parallel transmission of multiple nodes on a directional link; using space division multiplexing among the nodes to achieve the concurrent communication between multiple transmission nodes and multiple receiving nodes; when a network cluster head node receives RTS frames of all other nodes, running a multi-beam ad hoc network channel access allocation algorithm; and searching an optimal transceiving node pair set in each time slot, finding an edge set with the maximum network capacity as a channel access allocation result of each node in the next directional link time slot, and further implementing the simultaneous multi-transmission and multi-reception of the multiple nodes at the same frequency.

The invention provides an LED (Light Emitting Diode) indoor positioning navigation method and a positioning navigation system. An LED lamp serves as an emitting terminal; an emitting terminal driving device is used for controlling the strength of current so as to cause the change of brightness of the light and transfer the physical position data; the data frame with clear hierarchy of code element information is designed; zero bit filling is introduced into the sending and receiving of the data frame, so as to realize the transparent transmission and distinguish the frame header, the verifying code of the physical position information and the frame tail; the frame header has a specific coding sequence and can be detected, so that the validity of the data frame can be judged; the frame length of data frame can be analyzed; the invalid data frame can be timely detected and abandoned; different sizes of LED lamp sets with grid unit topology network structures can be designed according to different illuminating areas; only one of the LED lamps of a positioning unit is used for emitting the data frame at each time slot, and meanwhile, the other LED lamps all emit equidistant full zero data frames; the inter-symbol interference and the background noise are extremely reduced; the safety and reliability of the data frame are ensured.

The invention relates to wireless multimedia communication. In order to alleviate transmission quality shaking caused by an unreliable wireless channel when streaming media is transmitted in the wireless environment, further improve the transmission quality and increase the utilization ratio of the wireless channel. The technical scheme adopted by the invention is as follows: compared with a traditional speed control method, a speed control method in wireless streaming media transmission is characterized by comprising the following steps: obtaining the packet loss rate and business data passing rate parameters by smoothing treatment in a shorter interval; adjusting the streaming media transmission speed based on the parameters and an improved additive increase and multiplicative decrease algorithm, when the channel is in underload, determining the speed amplification by a variable constant additive factor and a constant additive factor determined by the packet loss, and when the channel is in overload, determining the speed reduction range by a variable constant multiplicative factor and a constant reductive factor determined by the packet loss; and setting a speed switching threshold, regarding the speed switching to be effective only when the difference between the current predicting speed and the previous predicting speed exceeds the set threshold. The speed control method in the wireless streaming media transmission is mainly applied to wireless multimedia communication.

The invention discloses a LoRaWAN channel conflict avoidance method based on time division multiple access. The method comprises the following steps: an LoRa node sending a network access request data packet with a sending period of the LoRa node; the LoRa TDMA server sending a network access receiving data packet with a LoRa node multicast address and a multicast address serial number, when a sending period of the LoRa node arrives, a corresponding bit being set in an issued multicast data load, and after the LoRa node receives multicast data, judging whether uplink data are sent or not. When higher channel utilization rate is required in some application scenarios, the LoRaWAN time division multiple access mechanism realized by multicast can greatly improve the channel utilization rate.

The invention provides a multi-service link distribution and reorganization device and method. The device comprises a service multi-link distribution module and a service multi-link reorganization module, wherein the service multi-link distribution module can classify services of different input service streams according to service quality requirements, detect available links, and then distribute the classified service streams to different links, and the classified service streams are sent out through a service multi-link transmission module; the service multi-link reorganization module is used for compensating for the time delay of the different links of the services which are received by a service multi-link receiving module so as to balance link loss, reorganize the service streams and restore original service streams. According to the scheme of the multi-service link distribution and reorganization device and method, link resources are distributed to the different services at the sending end according to link states and the service quality requirements, as a result, service transmission demands are met, and the utilization rate of system channel resources also can be increased; time delay and loss compensation can be conducted on data at the receiving end, and meanwhile, the out-of-order problem in parallel transmission is solved due to the fact that the same service is reorganized according to the type and package number of the service.

The invention discloses virtual MIMO (Multiple Input Multiple Output) relay transmission method and system based on cluster user cooperation. The method comprises the following steps of: dividing a plurality of user terminals adjacent in space into a cluster according to the distribution condition of the user terminals in cells by taking a virtual MIMO transmission technology between each user terminal and a base station, wherein each cell includes a plurality of clusters; modeling a channel between every two user terminals in the cluster to form a Ricean channel; modeling a channel between each user terminal and the base station to form a multipath reyleigh fading channel; and enabling two user terminals in the same cluster to mutually cooperate so as to finish the information transmission from each user terminal to the base station within three time slots. The system comprises the plurality of user terminals and the base station communicated with the plurality of user terminals, wherein clusters formed by the plurality of adjacent user terminals are mutually cooperated to finish the information transmission from each user terminal to the base station within three time slots. The invention remarkably improves the reliability of link transmission of the user terminals in a cellular mobile communication system by sufficiently utilizing the space diversity gain provided by the cooperation of users and also obtains higher utilization ratio of the channel.

The invention discloses a method for fast packet scheduling of an HSDPA system, comprising the following steps: a) estimating downlink channel quality indicator (CQI) of each user and calculating average CQI of the users in five time slots according to movement speed of the users and simulation environment; b) determining scheduling priority according to the requirements of quality of service (QoS) and the quality of the current channels of the users and QoS levels; c) selecting the users with highest priority to carry out scheduling, determining the transport block size, the code modulation method and the number of channels according to the current CQI of the users; d) if the channels is surplus, repeating the step c until the channels are totally distributed, and thus completing one-time scheduling. In the invention, fast packet scheduling of multiusers can be realized in multi-service environment, under the condition that the packet delay of different services and the packet loss rate are ensured, and the throughput in a subdistrict is improved by utilizing multiuser diversity. The invention can be applicable to a multi-service type HSDPA system in fast-moving environment, and provides the fast packet scheduling with QoS guarantee.

The method includes following steps: when node A (source node) and node B(destination node) needs to build up route, they send out a route-requested data package (RREQ)001 containing B message to the neighboring intermediate network node by using broadcast form; through retransmission of intermediate network node, more than one route-requested data package will arrive B 002; after B receives a route-requested data package, it responses a data package containing the address of B that is packetized and retransmitted to A 003 through intermediate network node; A reads out the whole route message from returned data package and sends the route message to B; multi whole routes are built up between the A and B.

Disclosed is a distributed routing protocol method for three-dimensional underwater acoustic sensor networks. Supposing that each node knows its own geographic location and channels are bidirectional and symmetrical, transponding cost is calculated and transponding nodes are selected according to factors such as the node location, utilization rate of the channel, energy, and the like when data transponding is required. Node energy is used as effectively as possible on the premise that other network performances are not affected, and balanced use of the energy of each node and the utilization rate of the underwater acoustic channel are considered. The purpose is to use the channel effectively so as to minimize energy consumption, improve the utilization rate of the energy and the channel of the networks, and prolong the service life of the whole networks.

The embodiment of the present invention provides a channel resource indication method and a device. The method comprises: request information sent by a station is received by an access point at a first channel, wherein the request information comprises first indication information for indicating that the station is a first type station which supports access point indication channel information, and the first channel is a minimum channel unit; and confirm information is sent to the station by the access point according to the request information, wherein the confirm information comprises channel information for the communication of the access point and the station, and the channel information at least comprises the first channel. According to the method, an access point is allowed to distribute channel resource according to the channel resource and the station types in the same BSS, and then send the confirm information to the station, so as to indicate the access point and the station to communicate on an indicated channel resource, and therefore improving the utilization rate of the channel and the flexibility of resource scheduling.

The invention relates to an adaptive automatic repeat request method, belonging to the wireless communication technology, which aims to combine channel coding with space-time coding, adjust the transmission modes adaptively, reduce repeat times effectively and improve the spectrum efficiency of the system. The invention is characterized in that a sending end is connected with a receiving end via a transmission link; the sending end has a plurality of transmission modes; a corresponding table of the transmission modes is formed; each transmission mode has a certain range of transmission times; a mode transmission graph of the transmission modes is formed. The invention has the advantages of adjusting channel coding mode, modulation mode and space-time coding mode via adjusting the transmission modes adaptively, reducing repeat times effectively, improving the channel utilization and the spectrum efficiency, reducing the implementation complexity and improving the performance of the system via ACK or NACK feedback choosing transmission modes flexibly when the slow channel is fading.

The invention discloses a multilink concurrent transmission method suitable for an underwater acoustic sensor network. The method can be divided into a channel competition process and a transmission planning process. The channel competition process is mainly as follows: a plurality of underwater acoustic nodes compete for a channel based on an improved RTS / CTS handshake protocol, transmission conflicts with other nodes in the data transmission process are avoided, and meanwhile nodes of mutually exposed terminals transmit data in a concurrent mode. In the data transmission planning process, when a plurality of sending nodes send data to a receiving node, the receiving node plans when the sending nodes send data, so that transmission conflicts are avoided, and the channel utilization rate is improved. The method aims to improve the network throughput as much as possible while avoiding transmission conflicts through an improved RTS / CTS handshake protocol, a modified back-off algorithm and a transmission planning algorithm. A simulation result in an EXata network simulation environment proves the effectiveness of the method.

An approach is disclosed for synchronization of frequency and / or phase in a full duplex network. The method may comprise sending a timing beacon over a single full duplex radio channel from a timing master to a timing slave; receiving the timing beacon over the single full duplex radio channel at the timing slave; sending a retransmitted beacon over the single full duplex radio channel from the timing slave to the timing master; and sending a delta of the timing beacon and the retransmitted beacon from the timing master to the timing slave. The beacon may contain a timestamp. The retransmitted beacon may include a delay calculation. A hybrid analog / digital self-interference cancellation system may be used at the timing master or the timing slave. The method may also include simultaneously sending and receiving the synchronization information over the single full duplex radio channel.

The invention discloses a virtual channel multiplexing scheduling algorithm based on a satellite network. The scheduling algorithm belongs to the technical field of the satellite network and is characterized in that one period of the virtual channel scheduling is divided into Nt time slots by adopting a mixed emergency / synchronization / asynchronization three-level multiplexing manner, wherein one part is used for an emergent virtual information channel, and the time slot number of the emergent virtual information channel is set as Nu; one part is used for a synchronous virtual information channel, and the time slot number of the synchronous virtual information channel is set as Ns; and one part is used for an asynchronous virtual information channel, and the time slot number of the asynchronous virtual information channel is Na. Compared with the prior art, the scheduling algorithm can process emergent data at first time taking account of the isochronism of audio and video data and flexibly and efficiently process asynchronous data with strong burstiness simultaneously, thereby improving the utilization rate of the information channel.

The invention discloses a method applied to an OFDM (Orthogonal Frequency Division Multiplexing) modulation system. Combination signal processing is performed in a frequency domain and a time domain. The system consists of an OFDM modulator, namely a sending end, and an OFDM demodulator, namely a receiving end. The method comprises the steps that before the sending end performs iFFT (Inverse Fast Fourier Transform), information is transmitted at even subcarriers, and 0 is filled in odd subcarriers; or the information is transmitted at the odd subcarriers, and 0 is filled in the odd subcarriers; or data is transmitted at the subcarriers capable of being divided exactly by 4, and 0 is filled in the rest of subcarriers to ensure that an effect of ICI (Inter-Carrier Interference) is further eliminated. A time domain waveform subjected to the processing has symmetry, and can be compressed; an opposite course is performed at the receiving end, and the waveform is subjected to reduction and FFT (Fast Fourier Transform) according to the symmetry; on the premise that the channel transmission efficiency is not reduced, the effect of the ICI can be reduced significantly, and a channel utilization ratio is not changed basically; and a core concept of the method is that adjacent subcarrier terms are compressed in the frequency domain in order to eliminate the effect of the ICI, and the time domain waveform is compressed in the time domain according to the symmetry in order to improve the channel transmission efficiency.

The communication system stores packet data received via a plurality of communication channels in a memory or transmits packet data stored in the memory through the communication channels includes buffer descriptors in which information on packet data is stored. The system comprises a central processing unit (CPU) which stores the information on packet data in the buffer descriptors and indicates whether each of the buffer descriptors is being organized, whether an error occurred in packet data received, or whether the organization of each of the buffer descriptors is completed by allotting a flag bit to each of the buffer descriptors. The system comprises a direct memory access (DMA) controller which stops processing a buffer descriptor currently being accessed and accesses a next buffer descriptor, or processes packet data information stored in the buffer descriptor currently being accessed, after identifying the flag bit of the buffer descriptor currently being accessed.

The invention discloses a channel access method and apparatus based on intelligent time slot selection. The problem that the dynamic topology of the network in a wireless sensor network and the efficient utilization of a channel cannot exist at the same time is mainly solved. The method comprises the following steps: establishing a model of the wireless sensor network, and combining a wireless sensor network environment with a reinforcement learning method; determining a customized frame structure and the number of time slots; initializing a state value vector V(s) and a time slot selection probability Pi; selecting a time slot according to the time slot selection probability Pi for transmission, and updating a reward value of each time slot according to the feedback condition of the channel access; then updating a state value v of the corresponding time slot and a qualification trace delta according to the reward of each node; after the update is completed, evaluating the state of each node, when Vi is greater than Vth, deeming that the node is in a stable state at the ith time slot, finally adjusting a temperature factor parameter of a Boltzmann strategy according to the above state evaluation state and the state value, and selecting an optimal time slot of the node for sending. By adoption of the channel access method and apparatus disclosed by the embodiment of the invention, the channel utilization rate of the wireless sensor network is not only ensured, the reliability of the wireless sensor network is also improved, and the application value is wide.

The invention discloses a data processing method and a data processing device. The data processing method comprises the steps of dividing data received by a receiver into first path data and second path data, acquiring burst packet starting point information and a transient frequency offset estimation value of the first path data, determining starting point information of the second path data according to the burst packet starting point information, carrying out transient frequency offset compensation on the second path data according to the starting point information of the data and the transient frequency offset estimation value, carrying out dispersion equalization processing on the second path after transient frequency offset compensation, and carrying out a subsequent data recovery operation on the second path data after dispersion equalization processing. The data processing method disclosed by the invention solves a problem of power frequency offset transient effects brought about by laser switching in related technologies, eliminates mutual effects among different DSP algorithms, compensates great line width and the frequency offset transient effects brought about by laser switching, and improves the channel utilization ratio of an optical burst coherent reception system.

The invention relates to a continuous variable quantum key distribution method based on a coherent optical communication system in the technical field of quantum key distribution, which includes the following steps: S1, superimposing a quantum signal on a coherent optical communication signal to achieve synchronous transmission of the coherent optical communication signal and the quantum signal; and S2, for the problem of carrier phase shift in the receiving process, carrying out carrier recovery through a digital signal processing technology to separate the coherent optical communication signal from the quantum signal. A quantum signal is superimposed on an original coherent optical communication signal so that a coherent optical system carries quantum signal information in the communication process. The carrier phase is recovered and classical and quantum signals are separated by the digital signal processing technology at the receiving end, and classical communication and quantum communication can be carried out simultaneously on the same set of equipment. The method not only can meet the needs of quantum key distribution, but also can reduce the cost of actual implementation and improve the channel utilization rate in communication.

The invention discloses a data processing method and system for verifying provision source authenticity. The method comprises the steps of: segmenting business data to acquire a plurality of data segments; performing functional data processing on each data segment to acquire a first section of Hash value corresponding to each data segment; acquiring a first source value of the entire business data according to the first section of Hash value; encoding the first section of Hash value and the first source value respectively by using a fault-tolerant coding algorithm so as to acquire a plurality of fault-tolerant encoded data; and combining the plurality of fault-tolerant encoded data with each data segment respectively, then packing the data segments into a business data packet and sending the business data packet. According to the invention, by reducing the load of functional data of the data packet, the channel utilization ratio of a transmission network can be increased, meanwhile, the requirement on business performance is satisfied.

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.

This invention relates to a forward EC method in single-way broadcast document transmission including the following steps: 100) depacketizing the to-be-sent data into multiple data blocks and computing the check sum of each data block; 200) processing XOR operation to the said multiple data blocks and computing protection data blocks; 300) sending contents of the data blocks including the protection ones; 400) receiving the data blocks; checking if the acquired data blocks are correct and making identifications; 500) adding up numbers of error data blocks; if there is only one error data block which has been accepted as a protection block, then correcting the mistake; and 600) direct split joint is carried out to resume the data in light of the coding rule, if there is no data error.

The embodiment of the invention provides an orbital angular momentum photon lantern manufacturing method and device. The method comprises the following steps: placing the preset amount of optical fibers in a glass sleeve with a low refractive index, wherein the preset amount and the geometric arrangement way of the optical fibers and the mainstream photon lantern design are maintained consistency;performing heat insulation tapering on the glass sleeved with built-in optical fibers to the preset stretching length according to a preset stretching ratio, wherein the type of the optical fiber comprises a single-mode optical fiber, and the stretching ratio is used for controlling the normalization frequency value of a few-mode optical fiber obtained after tapering, thereby enabling the photonlantern to product a linear polarization LP mode, wherein the stretching length is used for controlling a phase difference of the LP mode at pai / 2. A target mode can be produced without simultaneouslyselectively exciting two single-mode optical fiber ports of the photon lantern, the OAM+ / -1 mode can be reused at the same time, and the channel utilization efficiency is high. Furthermore, the reusing of the OAM mode can be realized without importing an additional device, and the manufacturing method has strong practicability and is simple in use process.