199results about How to "Improve communication capacity" patented technology

The invention belongs to the field of satellite communication technologies and particularly relates to a ground station system and a method for avoiding collinear interference with a geostationary satellite. The system comprises a ground station located at one position of the earth and a non-geostationary satellite constellation connected to the ground station, wherein the ground station traces one satellite in the non-geostationary satellite constellation through controlling antenna beam and establishes a communication link with the satellite; when a connecting line between the ground station and one non-geostationary satellite points at the geostationary satellite, the ground station adjusts the beam direction and selects another non-geostationary satellite in the different direction in view to communicate, so that the collinear interference with the geostationary satellite is avoided. According to the ground station system and the method, the restriction that shutdown of the non-geostationary satellite is needed or the transmitting power of the non-geostationary satellite is greatly reduced when the collinear interference occurs is avoided, and the satellite communication of the ground station keeps continuous, so that the availability and the message capacity of the non-geostationary satellite constellation are improved and the same frequency coexistence of the non-geostationary satellite and the geostationary satellite is realized.

The invention relates to a serial-parallel connection modulation optical frequency multiplication millimeter-wave RoF (Radio Over Fiber) system and a QPSK (Quadrature Phase Shift Keying) / 16QAM (Quadrature Amplitude Modulation) modulation method thereof. The system comprises a central station, a base station and fiber connection thereof, wherein the central station comprises a single longitudinal mode laser, a double-electrode Mach-Zehnder optical modulator, an IQ optical modulator, two microwave signal sources, a pi phase shifter, a pi / 2 phase shifter and an erbium doped fiber amplifier; and the base station comprises an optical detector, a front low-noise amplifier, two millimeter-wave bandpass filters, two millimeter-wave amplifiers, a millimeter-wave duplexer and a millimeter-wave antenna. In the method, the cascading of the double-electrode Mach-Zehnder optical modulator and the IQ optical modulator is adopted, and a balanced optical waveguide structure formed by integrating the two optical modulators avoids the influence of optical source phase interference noise caused by support arm optical delay inequality on modulation signals.

The invention discloses a multi-carrier code division multiplexing light transmission system and a multi-carrier code division multiplexing light transmission method based on ultra dense wavelength division multiplexing. The system comprises a multi-carrier light source generating part, a modulating part, a multiplexing part, a demultiplexing part, a demodulating part and a signal processing part which are sequentially connected. Firstly, a multi-carrier light source is generated by a single-frequency light source; then the modulating part modulates each branch electric signal onto a corresponding optical carrier; the multiplexing part is used for multiplexing each modulated optical carrier into an optical fiber channel; the demultiplexing part is used for separating each optical carrier in the signals to conduct signal recovery; the demodulating part is used for demodulating each branch signal; and the signal processing part is used for carrying out compensation on the demodulated signals. The method disclosed by the invention is fused with a code division multiplexing technology, a subcarrier modulating and demodulating technology, a wavelength division multiplexing and demultiplexing technology, a subcarrier demodulating technology based on coherent demodulation and the like. The multi-carrier code division multiplexing light transmission system and the multi-carrier code division multiplexing light transmission method based on ultra dense wavelength division multiplexing improve the message capacity of a network system and have the advantages of simpleness for capacity expansion, reliable performance and the like.

The invention relates to a method for improving the message capacity of a mobile ad-hoc network by the combination of the link layer messages, belonging to the computer communication field. The method includes that firstly, the newly-produced network layer message is added into the different buffer queues of a sending buffer at the sending terminal according to the next hop address and the network layer message is combined with the message at the tail of the former queue and processed according to the length of the network layer message or is stored as an opposite message; when the received link layer message is extracted at the receiving terminal, the data length of the link layer is compared with the length of the network layer message and then judged, and each network layer message extraction is completed through cyclic processing. With the method of the invention, only little modification to the current protocol stack can help obviously improve the message capacity in the mobile ad-hoc network under high busy state; the method has the advantages of simple computation, small computation complexity and easy achievement.

The invention discloses a millimeter wave full duplex unmanned aerial vehicle communication relay transmission method, and belongs to the technical field of millimeter wave communication. The method comprises the following steps: constructing a communication scene from a ground base station to a ground user by taking an unmanned aerial vehicle as a relay, and establishing a channel model of a downlink communication system from the ground base station to the user by taking the unmanned aerial vehicle as the relay by utilizing a spatial position model; in the simultaneous same-frequency full duplex mode, enabling the ground base station to transmit a signal to the unmanned aerial vehicle, and enabling the unmanned aerial vehicle to transmit a signal to user equipment; designing the optimal position of the unmanned aerial vehicle under the ideal beamforming condition, giving the position optimization beamforming vector of the unmanned aerial vehicle, and giving the beamforming vector to optimize the power of the base station and the unmanned aerial vehicle transmitting signal. According to the method, for a downlink transmission system taking an unmanned aerial vehicle as a relay, thecoverage range of millimeter wave communication is expanded, the communication capacity of the system is improved, and optimal power control under any given unmanned aerial vehicle relay position andbeam forming is provided.

The invention provides a traffic flow characteristic based dynamic grouping resource distribution method. The traffic flow characteristic based dynamic grouping resource distribution method comprises the steps of firstly dividing V2V communication links into two types, wherein one type is a traffic safety type and the other type of an entertainment type; selecting a suitable grouping number value m based on a specific traffic flow characteristic and grouping the two types of the V2V communication links respectively; then selecting a cellular user resource corresponding to the maximum communication capacity utility value and distributing the cellular user resource to each V2V link under the precondition of guaranteeing the communication quality of the cellular user, wherein the V2V communication links in each group reuse the same cellular user resource. A simulation result shows that the method disclosed by the invention, although is not as good as a greedy algorithm in the aspects of the communication capacity utility value and the number of the V2V links for obtaining the communication resource successfully, has great advantages when being compared with a random distribution algorithm. In addition, the method disclosed by the invention is obviously superior to the greedy distribution algorithm and the random distribution algorithm in the aspects of running time and spectrum frequency; and the two performance indexes are particularly important for the complex and changeful V2V communication link environment and the existing spectrum resource scarcity condition.

The invention discloses a 1.2m feedback full-automatic portable emergency satellite communication antenna servo system which comprises a portable box, an antenna structure unit and an antenna control unit, wherein the antenna structure unit and the antenna control unit are arranged in the portable box; the antenna structure unit comprises an antenna mount, a six-section carbon fiber antenna main reflection surface and a feed source component support frame, wherein the six-section carbon fiber antenna main reflection surface and the feed source component support frame are connected to the antenna mount, an antenna auxiliary reflection surface is installed at the end part of the feed source component support frame, a feed source component support plate is installed in the middle of the feed source component support frame, a feed source component is installed on the feed source component support plate, a direction drive device and an elevation drive device are arranged in the antenna mount, and the feed source component comprises a feed horn, a polarizer, a duplexer and a polarization power transmission mechanism. The 1.2m feedback full-automatic portable emergency satellite communication antenna servo system is reasonable in design, convenient in implementation, increased in communication bandwidth, expanded in communication capacity, high in degree of intelligence and working reliability, convenient to carry and good in use effect, provides communication guarantee for the emergency handling and is convenient to popularize and apply.

The invention relates to the technical field of satellite communication, in particular to a Beidou communication device and method. The Beidou communication device comprises a Beidou transmitting-receiving main machine and a server, wherein the Beidou transmitting-receiving main machine is used for parallely transmitting and parallely receiving Beidou short messages, and the server is used for storing the Beidou short messages transmitted or received by the Beidou transmitting-receiving main machine and issuing the received Beidou short messages. The Beidou communication method comprises the steps of parallely transmitting and parallely receiving the Beidou short messages, storing the Beidou short messages transmitted or received by the Beidou transmitting-receiving main machine, and issuing the received Beidou short messages. According to the Beidou communication device and method, one-time transmitting message capacity is improved, and the parallel mode can achieve large volume data information issuing and warning information can be transmitted to a plurality of different areas in a grouping mode on the premise that the frequency of communication is kept unchanged.

The embodiment of the invention relates to an access station selecting method, an access station switching method, an access station accessing method, and equipment thereof. The access station selecting method comprises the following steps: when preamble signals are detected, acquiring attribute information on various levels of candidate access stations at the periphery of a current mobile station according to the preamble signals, wherein the attribute information at least comprises types and hops of the candidate access stations; and selecting a target access station suitable for the current mobile station from the candidate access stations according to the acquired attribute information of the candidate access stations. The access station selecting method, the access station switching method and the access station accessing method optimize the selection, access and switching of the access station suitable for the current mobile station to improve communication quality and communication capacity.

The invention provides a silicon-based WDM optical transceiver module comprising a silicon photonic chip including a modulator array and a detector array; and a wavelength division multiplexer and a demultiplexer achieved based on a planar lightwave circuit (PLC). The wavelength division multiplexer and the modulator array are connected through packaging. The demultiplexer is connected to the detector array connected through packaging. A WDM optical module is achieved by packaging the wavelength division multiplexer chip and the demultiplexer chip through the silicon photonic chip and the PLC so as to avoid process difficulty of the silicon-based wavelength division multiplexer / demultiplexer. In view of low integration and high power consumption of a traditional WDM optical transceiver module based on discrete devices and PLC, the modulator array and the detector array are integrated by using silicon photon technology so as to greatly improve the integration of optical transceiver module and to reduce power consumption.

The invention provides a joint resource optimization method based on an underwater acoustic OFDM-NOMA (Orthogonal Frequency Division Multiplexing-Non-Orthogonal Multiple Access) system downlink and isused for solving a problem that in the prior art, no underwater non-orthogonal multiple access network resource allocation mechanism with high feasibility exists. An underwater acoustic wireless communication system based on OFDM-NOMA is established. A base station (BS) and K anchor nodes are deployed in the system. A channel information state of each anchor node is known. A constraint conditionis given. The constraint condition comprises a total transmitting power Pt of the base station and a constraint of subcarrier allocation number. A system rate sum is taken an objective function. In order to solve a joint resource optimization problem, the provided optimization problem is finished step by step. Subcarrier allocation is carried out through adoption of a greedy algorithm with relatively low algorithm complexity, so a system subcarrier allocation optimization objective is satisfied. For power allocation, an optimization objective is converted from a transmitting power to a communication rate, a power allocation model is converted into a strict convex optimization problem, and an optimum value is solved through adoption of a GP (Geometric Programming) algorithm. The method is scientific and reasonable, is low in algorithm complexity and is applicable to an underwater bad communication environment.

The invention discloses a two-dimensional grating coupling-based silicon-based QPSK (Quadrature Phase Shift Keying) photomodulator, comprising a two-dimensional grating coupler, four mode transducers, a single-mode waveguide, an optical cross and four radio frequency phase shifters, wherein the two-dimensional grating coupler, serving as a vertical optical coupling interface and a four-channel powder divider, averagely splits a coupling light into four channel waveguides; the four mode transducers are used for carrying out mode conversion and insulated optical transmission between the two-dimensional grating and the single-mode waveguide; the single-mode waveguide is used for carrying out low-loss single-mode transmission of an optical signal; the optical cross is used for carrying out non-crosstalk low-loss optical cross transmission between two waveguides; the four radio frequency phase shifters are used for loading electric signals of in-phase road data DATAI and quadrature road data DATAQ, thus achieving BPSK (Binary Phase Shift Keying) light phase modulation of two roads. Two of three MMI beam combiners are applied to light beam combination of two branch circuits in the in-phase road and the quadrature road; the other MMI beam combiner is applied to light beam combination of the in-phase road and the quadrature road; two thermal optical phase shifters are used for adjusting an optical wave phase difference between the in-phase road and the quadrature road by direct current, so as to meet pi / 2, and thus the optical signals of the in-phase road and the quadrature road are synthesized into a QPSK modulation signal.

The invention discloses a latent communication system and method based on a non-cooperative blind source. The latent communication system comprises an information coding and transmitting end, an information receiving and demodulating end and a non-cooperative blind source signal, a non-cooperative blind source is used as a communication carrier wave, double antennas or multiple antennas are used as receiving ends, received electromagnetic waves are demodulated in a receiver, and therefore hidden transmission and passive transmission communication of information are achieved. By adopting the technical scheme of the invention, a signal emission source is not needed, the carrier emission power is saved, and new spectrum resources are not occupied; the circuit structure is simplified, and thehardware cost is reduced; concealed communication is guaranteed in the physical level, and indoor directional fixed-point communication can be achieved. Information can be sent to a sensor at a specific position in the Internet of Things, energy is provided for the radio frequency identification tag, and the wireless communication quality is improved.

The invention discloses a channel quality indication predicting and compensating method and a channel quality indication predicting and compensating system. The method comprises the following steps of: accumulating CQI values of the same subband or full bandwidth at same intervals to form a CQI time sequence; identifying an autoregressive summarization moving average model, namely according to the CQI time sequence, identifying the process of the autoregressive summarization moving average model and determining parameters in the autoregressive summarization moving average model; estimating the parameters of the autoregressive summarization moving average model to determine the autoregressive summarization moving average model; and predicting the CQI values based on the determined autoregressive summarization moving average model. The method can effectively reduce the difference of the original CQI values and a true value at the current moment so as to save communication resources and energy and improve the system communication capacity; and the method also has the advantages of low complexity of algorithms and convenient implementation.

The invention discloses a flip-chip structure micro-size photonic crystal LED array chip and a preparation method thereof. The LED array chip of the invention has four light emitting units connected in parallel, the metal connecting line of the positive electrode and the semiconductor material are separated by a dielectric insulation layer, and the negative electrode is directly covered on the upper surface of the semiconductor material. The active region of the light-emitting unit has a photonic crystal with periodic distribution, and the depth of the photonic crystal exceeds the depth of theactive layer. Except electrode pad, DBR is distributed on the whole chip surface. Metal electrodes form metal mirrors. The preparation method of the invention adopts the scheme that an ohmic contactlayer and an electrode are firstly prepared and then a photonic crystal is etched without planarizing and the like traditional process flow; Using thick strip dielectric insulating layer to insulate the electrode from semiconductor material and thin dielectric mask layer and adhesive mask layer to etch together is conducive to the deposition of DBR and the rapid escape of photon mode. The processflow of the invention is simple and reliable.

The invention is applicable to the field of communication, and provides an antenna and a wireless router. The antenna comprises a radiator, a director, at least one wave absorber and a reflector, wherein relative to the radiation direction of the radiator, the director is in front of the radiator, the reflector is behind the radiator, and the wave absorber is located on a side face of the radiator; and the radiator comprises a base plate, a composite left and right hand transmission line unit attached to a front face of the base plate, an electromagnetic field band gap EBG structure attached to a bottom face of the base plate, and a flat metal plate located on the side of the EBG structure and connected with the composite left and right hand transmission line unit to serve as the ground. The antenna provided by the invention has the advantages of small size, low profile, horizontal omnidirectional radiation, high efficiency and wide bandwidth.

The invention relates to an underwater main base station of a seabed observational network. The underwater main base station comprises an anti-dragging network structure and a function unit. The anti-dragging network structure is of an integrated ellipsoidal face structure and is formed by connecting a protective cover assembly, a supporting framework assembly, a bottom supporting assembly and a bottom sealing assembly through bolts and nuts. The function unit is installed in the anti-dragging network structure and formed by connecting a submarine cable terminal assembly, a power unit assembly, a communication unit assembly, a submarine cable connection cathode assembly and a wet pluggable connector assembly through watertight connectors and watertight cables. The underwater main base station is connected to a bank base station through a standard single-electrode photoelectric composite communication submarine cable comprising a seabed relay and a seabed splitter. Negative high voltage single-electrode direct-current transmission with seawater as a current loop is adopted for communication with a wavelength division multiplexing optical fiber with a relay, and the reliability of the seabed observational network is improved through submarine cable segmental relay protection. The underwater main base station is simple in structure, compact in size, stable in arrangement and capable of reducing external force damage risks and reducing sediment deposition and further has the beneficial effects of being high in transmission efficiency, large in communication capacity and long in transmission distance.

The invention relates to the technical field of a semiconductor laser, and proposes a single-mode emission orbital angular momentum (OAM) laser. A cavity body of a resonant cavity of the laser is of amicro column, micro ring or micro disc structure for supporting an echo wall mode, a grating or defect is etched on an outer side surface of the cavity body of the laser, the echo wall mode with special angular quantum number can be selected as a hot shot mode of the laser, the selected mode is vertically scattered and output by a top grating, the output is a travelling wave mode with a vortex phase, namely an OAM mode, the top grating is arranged at a position, near to an outer side edge of a micro column, of a grating layer and comprises a real part and a virtual part, the real part and thevirtual part comprise two groups of gratings and are used for respectively modulating effective reflectivity of the mode, so that scattering output of the travelling wave mode is formed. The laser issmall in cavity volume and low in loss, and thus, ultrahigh-speed modulation can be achieved. The semiconductor laser has the characteristics of small volume, single-mode working and low threshold current, and is convenient to detect, a two-dimensional array is easy to integrate, output light is easy to couple to optical fiber, and various advantages can be achieved on different material systems.

The invention discloses an access method for a passive beam splitting RS-485 optical fiber bus. The method is characterized by including the following steps of firstly, setting an RS-485 bus control side; secondly, setting a passive RS-485 optical network local side; thirdly, setting a passive RS-485 optical network terminal; fourthly, setting a user terminal device; fifthly, sending a control signal through the RS-485 bus control side, converting the control signal into an optical signal through the passive RS-485 optical network local side, transmitting the optical signal to the passive RS-485 optical network side, and converting the optical signal into an RS-485 bus logic signal so as to control the user terminal device; sixthly, making the user terminal device convert a feedback data signal into an optical signal through the RS-485 optical network side, transmitting the optical signal to the passive RS-485 optical network local side through an optical fiber, converting the optical signal into an RS-485 bus level signal or an RS-232 level signal through the passive RS-485 optical network local side, and transmitting the RS-485 bus level signal or the RS-232 level signal to an RS-485 interface or an RS-232 interface of the RS-485 bus control side. The invention further discloses a system for implementing the method.

The invention discloses a free space laser communication system based on quantum encryption. The system comprises a receiving module and a data decryption module, wherein the receiving module capturesa laser signal and a communication request signal, amplifies, processes and quantizes the laser signal through broadband amplification and pulse code modulation, codes the laser signal and then converts the laser signal into a digital signal. A computer module processes data, and then records communication node information and freely organizes a communication network according to a communicationrequest and transmits data to a data encryption module; a quantum key terminal obtains a quantum key, the data encryption module encrypts the data, and the encrypted data is transmitted to a counter party of communication through a transmitting module. A receiving party communication node obtains the quantum key through the quantum key terminal and decrypts the received data through the data decryption module, and further transmits the decrypted data to the computer module for processing. For the system provided by the invention, fixing communication nodes or paving electric cables / optical cables is not needed, and the system can perform long-distance transmission and avoid obstacles and bad weather regions.

The invention discloses an optical fiber eigenmode multiplexing communication method and system. The method comprises the following steps: directly taking optical fiber eigenmode as an information carrier, and then performing low-crosstalk multiplexing transmission on multiple optical fiber eigenmodes in the eigenmode separated multi-model optical fiber. The system comprises a transmitting end, a multichannel eigenmode multiplexer, the eigenmode separated multimode optical fiber, the eigenmode separated optical amplifier, a multichannel eigenmode de-multiplexer and a receiving end; the effective refractive index difference between the multichannel optical fiber eigenmodes supported by the eigenmode separated multimode optical fiber is large and the crosstalk is low; the multichannel eigenmode multiplexer realizes the conversion and the multiplexing to the optical fiber eigenmode from the multichannel Gaussian mode; the multichannel eigenmode multiplexer realizes the conversion and de-multiplexing to the Gaussian mode from the multichannel optical fiber eigenmode; the multiplexing and the de-multiplexing are extensible and provide the single mode optical fiber interface. The optical fiber eigenmode multiplexing communication method disclosed by the invention supports the low-crosstalk multiplexing communication of the multichannel optical fiber eigenmode, the multi-in and multi-out digital signal processing is unnecessary, the single model optical fiber is compatible, and the communication capacity and the spectrum efficiency can be effectively improved.

The invention discloses a multi-input and multi-output optical communication system and a signal recovery method thereof. The multi-input and multi-output optical communication system comprises an optical signal transmitting end and an optical signal receiving end, wherein the optical signal transmitting end comprises a light intensity modulation unit and an optical signal sending unit which are mutually connected, the optical signal sending unit comprises n broadband light sources which have mutually overlapped, but not totally identical frequency spectra, and the light intensity modulation unit is used for respectively modulating n lines of signals to corresponding optical modulation signals generated by the n broadband light sources; the optical signal receiving end comprises a light splitter, an optical signal receiver and a signal processing unit; the light splitter enables incident light at different frequencies to form different light intensity distributions after the incident light passes the light splitter, and the light intensity angle distributions generated by the incident light at the same frequency after the incident light passes the different parts of the light splitter are also different; the optical signal receiver is an optical detector array constituted by n optical detectors with same frequency spectral response. The multi-input and multi-output optical communication system disclosed by the invention can realize large-capacity signal transmission while illuminating and is further simple in structure and easy to implement.

The invention discloses a method and a system of cooperative communication among vehicle-mounted mobile stations. The method comprises that a relay station is installed at a traffic intersection; two links are built, the two links comprise a communication link (V2R) and a communication link (R2V), wherein the vehicle-mounted mobile stations send signals to the relay station through the communication (V2R), and the relay station sends signals to the vehicle-mounted mobile stations through the communication (R2V); and among the vehicle-mounted mobile stations, communication is achieved through the two links. The method and the system solve the technical problems that under a traditional transmission mode without the relay station, when a base station is far away from the traffic intersection, signal loss between the vehicle-mounted mobile stations and the base station is overlarge to lead to poor receptivity, and therefore, the throughput of the system is improved on the condition that transmitted power is not increased.

The invention discloses a quantum secure direct communication method based on photon orbital angular momentum coding, comprising the following steps: constructing two unitary operators and giving two groups of complete intrinsic quantum states; when quantum secure direct communication is carried out, based on an intrinsic quantum state space, randomly preparing, by a receiving party, a group of photon sequences, and sending to a sending party; randomly choosing, by the sending party, a check photon from the photon sequences to measure Z<^>p or X<^>p and comparing a measurement basis and a measurement result by a public channel; judging whether a communication channel is secure according to an error rate of the measurement result; if the channel is secure, carrying out coding operation on the photons by the sending party; measuring the received photons by the receiving party, comparing an initial state and a final state of a photon orbital angular momentum, obtaining the coding operation carried out by the sending party and constructing coded logic bit information sent by the sending party. According to the method disclosed by the invention, by using the photon orbital angular momentum coding, the communication capacity and the spectral efficiency of the quantum secure direct communication are improved.

The invention discloses an N-mode multiplexer / demultiplexer based on an asymmetric Y-furcate structure. The N-mode multiplexer / demultiplexer is formed by cascade connection of N-1 asymmetric Y furcates. Each asymmetric Y furcate comprises a main waveguide, a wide branching waveguide and a thin branching waveguide. The wide branching waveguides are larger than the thin branching waveguides in width. The sum of the widths of the wide branching waveguides and the widths of the thin branching waveguides is equal to the widths of the main waveguides. The included angles of the positions where the wide branching waveguides are intersected with the thin branching waveguides are smaller than 1 degree. The main waveguides and the wide branching waveguides of two adjacent asymmetric Y furcates are connected through tapered heat insulation waveguides. The widths of the main waveguides of the two adjacent asymmetric Y furcates are different. The N-mode multiplexer / demultiplexer has the advantages of achieving transmission of a plurality of data channels, being large in bandwidth and low in loss and crosstalk, and the like.

The invention relates to a method for reducing media access conflict of a wireless local area network through cross-layer architecture, belonging to the computer communication field. The method comprises two parts of processing of node interception messages and processing of transmitted messages during the process of message transmission; a sequence mark is set for each node; following status information is stored in various nodes: node sequence marks used for transmission of the prior message of the nodes, node sequence marks of messages intercepted lately and physical addresses of the node sequence marks; node interception reads corresponding control information for all received messages; and the status that whether a transmitting buffer of the node is empty and a transmitting node sequence mark which is represented by a nonnegative integer are added into a message header during the process of packaging the messages into frames. The method fully utilizes the status information of the various nodes in the network through the cross-layer architecture to reduce the probability of the conflict in a small-scale wireless local area network and then further achieve the aim of improving the message capacity in the wireless local area network.

The invention discloses a passive light-splitting RS-485 optical fiber bus local side system. The system is characterized in that the two ends of the system are connected with an RS-485 bus control terminal and a passive RS-485 optical network terminal of an industry optical fiber bus for passive light splitting respectively. The system comprises a power module, a main control panel, a plurality of plane waveguide optical dividers and a plurality of light ports which are connected. The main control panel comprises an RS-232 center control interface, an RS-485 center control interface, two RS-485 cascade interfaces, a plurality of photoelectric conversion modules and a bus arbitration processor. The RS-232 interface and the two RS-485 cascade interfaces are connected with the bus arbitration processor and the RS-485 bus control terminal. One ends of the multiple photovoltaic conversion modules are connected with the bus arbitration processor, and the other ends of the multiple photovoltaic conversion modules are connected with one ends of the plane waveguide optical dividers. The other ends of the plane waveguide optical dividers are connected with the light ports.

The invention discloses a metasurface orbital angular momentum array antenna with good reflectivity. The array antenna is an array phase plate formed by arranging more than two phase-shifting units, each phase-shifting unit comprises a dielectric layer, the surface of the dielectric layer is provided with square annular metal patches; the bottom portion of the dielectric layer is provided with metal grounding layers, the array phase plate is divided into a first quadrant, a second quadrant, a third quadrant, a fourth quadrant, a fifth quadrant, a sixth quadrant, a seventh quadrant and an eighth quadrant in the clockwise direction, the superficial area of the metal patch in each quadrant is the same, and the superficial areas of the metal patches on the phase-shifting units in the first quadrant, the second quadrant, the third quadrant, the fourth quadrant, the fifth quadrant, the sixth quadrant, the seventh quadrant and the eighth quadrant are decreased in order. The metasurface orbital angular momentum array antenna has a very excellent incident wave reflection vortex effect, the reflection efficiency can reach more than 70 percent, and the metasurface orbital angular momentum array antenna has good energy transmission efficiency; in addition, the metasurface orbital angular momentum array antenna has the advantages of the simple structure, high utilization rate of unit areasof the phase-shifting units, the simple manufacturing process and the low cost.

The invention discloses a system for realizing a topological structure of a controller area network (CAN) bus and relates to the field of industrial control. The system comprises master equipment, an attached resource computer network (ARCnet) bus, bridge equipment and CAN equipment, wherein the master equipment and the bridge equipment are respectively connected with the ARCnet bus; the CAN equipment is connected with the bridge equipment; and the bridge equipment is used for realizing data exchange between the ARCnet bus and the CAN equipment and protocol switching between an ARCnet protocol and a CAN protocol. By adoption of the system, the problems of lower transmission speed rate of the CAN bus and limitation on quantity of nodes are solved, and the implementation cost of the system is reduced.