46results about How to "Good anti-multipath effect" patented technology

The invention discloses a wireless indoor positioning method and a device based on environmental backscattering. The method comprises steps: a radio frequency source RFs transmits signals; a label performs environmental backscattering; a mobile terminal Q detects the received label signals; and three-dimensional positioning on the mobile terminal is finally carried out. The device comprises the radio frequency source, the label and the mobile terminal. The environmental backscattering technology is used to be combined to multi-antenna label beam scanning, indoor and real-time three-dimensionalpositioning is realized, and the method and the device have the advantages of low power consumption, good anti-multipath effects are good; the safety is high; the system complexity is low; and the like.

The invention provides an indoor positioning method based on environmental backscattering. The indoor positioning method comprises the following steps that step one, a radio frequency source RFs emitsa signal: the tags of which any three of more than four tags are not arranged at the spatial position of the same plane are included; step two, environmental backscattering of the tags: the tags receive the signal of the radio frequency source RFs and transmit the signal to a mobile terminal Q through the backscattering mode; step three, the mobile terminal Q detects and positions the received tag signal: the four tags of the maximum signal intensity RSSI value are selected and recorded as Ta', Tb', Tc' and Td'; and step four, a unique triangular pyramid can be determined by four coordinatesand the position coordinates (x, y, z) of the unique mobile terminal Q can be determined through the triangular pyramid. The useful signal receiving power of the target can be enhanced, the coverage space can be increased, the method has great anti-multipath effect, the arrangement number of the tags can be saved and the cost of the positioning device can be reduced.

The invention provides a passive radar low-altitude object detection method. The distance between an object and an array is detected by installing a circular passive receiving radar antenna array, receiving OFDM communication signals reflected by a low-altitude slow-speed object and performing pulse compression, then a weak object under a low signal-to-noise ratio and strong interference is detected through a constant false alarm detection module, and finally, determination and advanced early warning of a low-altitude object with a potential threat are carried out through extracting the speed of the detected weak object. The method provided by the invention decreases the cost under the condition that the coverage scope is ensured by use of OFDM wireless communication signals through a passive radar system, and compared to a conventional OFDM phase-coded radar, is greatly simplified in terms of system; and the method is suitable for application in key areas which are covered by the OFDM wireless communication signals and require monitoring of low-altitude safety by use of such features of high utilization rate of an OFDM signal spectrum, good anti-multipath performance, high-distance resolution with broadband, adaptability of narrowband to a low noise-to-signal ratio and the like.

The invention discloses an octagonal flat-type array antenna comprising an earth plate and a circularly-polarized four-point feeding network, wherein the earth plate is provided with a central radiating element assembly and two groups of coupling plates arranged by equal distance along the radial direction. The octagonal flat-type array antenna can receive signals transmitted by a plurality of navigation and positioning satellite constellations and meet the requirement for high-precision carrier phase measurement. A high-precision receiver antenna for GNSS (Global Navigation Satellite System) carrier phase measurement can be provided for users of ocean, land, air and space, and the octagonal flat-type array antenna can also be popularized and applied to a radio transmitting and receiving system with a stable radiating phase center and a circular polarization and hemisphere beam coverage requirement. The octagonal flat-type array antenna has the characteristics of stable radiating phase center, circular symmetry of radiation pattern, high roll-off, high front-to-back ratio and favorable wide angle circular polarization, has favorable anti-multipath and broadband operation capacity and is a novel GNSS high-precision carrier phase measurement type user compatible receiver antenna.

The invention discloses a method and a device for sending and receiving data in high-sensitivity narrow band wireless communication. The method comprises the steps of treating two continuously reversed linear frequency modulation signal as a synchronous sequence in a front synchronizing head, treating two same complex sine signals as reference symbols in the front synchronizing head, and then forming a frame to be sent tighter with baseband data to be sent through a sending end; modulating the frame to be sent to two in-phase orthographic carriers to form and send a radio frequency sending signal. With the adoption of the method, the angle features can be jointly demodulated without precise frequency offset estimation by the FFT algorithm and the phase; the various conditions and algorithm advantages are combined, so that the single bit calculation quantity is greatly reduced, and moreover, the receiving sensitivity can be improved, and the data transmission distance can be increased.

The invention includes steps: receiving a training sequence (midamble) data r in a time slot; carrying out channel estimation so as to obtain impulse response hfreq of channel influenced by frequency deviation; detecting component of midamble data transmitted; estimating impulse response h of channel not influenced by frequency deviation; estimating received midamble data r' not influenced by frequency deviation; carrying out estimation of frequency deviation through maximum likelihood method, and outputting estimated frequency deviation. Being adapted to system composed of multiple sub codes such as system of training sequence of TD - SCDMA, the invention possesses favorable antimultipath performance, simple and easy of implementation.

The invention discloses a mechanism for controlling media access of a wireless mesh network. A media access control structure based on the synchronous channel switching mechanism is constructed on a radio chip which supports multiple channels. In the process of network operation, an adaptation transmission mechanism based on the media access control structure is adopted to adaptively select a high-quality channel for communication and a selecting method of a channel switching mode is adopted to realize concurrent transmission to a great extent. Then the highly reliable mechanism for controlling media access of a wireless mesh network is formed and is applicable to the industrial field. The invention makes full use of the multi-channel ability provided by physical radio frequency hardware, optimizes the performance of the wireless network under the industrial communication environment of multi-network coexistence, multi-path phenomenon and strong electromagnetic noise and guarantees high-quality communication in the rugged industrial radio frequency environment.

The invention discloses a wireless positioning monitoring system and method based on a UWB technology. The system comprises a single base station; an antenna array; a radio frequency module, a monitoring service station, and a label which are connected with the antenna array; an acquisition module and a display screen connected with the label; the acquisition module comprises a far infrared metering module, an air volume and wind speed sensor, a methane gas sensor, and a PM2.5 dust sensor; the antenna array, the monitoring service station and the label are respectively connected with the single base station. A single base station synchronization header is used for time synchronization of the label with the time before positioning the single base station; the single base station with an antenna is used for measuring the distance and angle between the label and the single base station through a TOA positioning technology and an AOA positioning technology, thereby obtaining a three-dimensional position of the label; the detected information is transmitted to the monitoring service station via the acquisition module through the single base station; if the information value of a dangerous linkage source exceeds a normal range value, the system performs an alarm. The wireless positioning monitoring system and method based on the UWB technology in the invention have the advantages oflow power consumption, anti-interference, low complexity, high transmission efficiency and accurate positioning.

The invention discloses a two-dimensional vacant code index modulation method based on machine learning. The two-dimensional vacant code index modulation method mainly comprises the following steps of1) carrying out serial-parallel conversion on the sending information bits u of a transmitting end; 2) establishing an optimal antenna subset based on an SVM, and constructing a label and antenna combination mapping table; 3) carrying out symbol modulation and index modulation on the sending information bit u after serial-parallel conversion, thereby determining a transmitting antenna, a modulation symbol and a spread spectrum PN code; 4) performing spread spectrum on the modulation symbol, and transmitting the spread spectrum to a receiving end; and 5) using the receiving end to receive thespread spectrum signal and perform the correlation characteristic detection on the spread spectrum signal; 6) performing estimation detection on the despread signal by using the CNN; and 7) demodulating and demapping the estimated demodulation symbol and antenna with the PN code index value so as to restore the source information bit. According to the method, the advantages of a spread spectrum technology in spatial modulation and code index modulation are combined, the multi-antenna channel link resources are utilized, and due to the fact that the spread spectrum technology is used, the method has certain anti-interference and anti-multipath capacity.

The invention discloses a vehicle-vehicle communication system based on an UWB. The vehicle-vehicle communication system comprises a main control unit, an information collecting unit, a data storage module, a wireless communication module and a power supply module. The output end of the power supply module is electrically connected with the input end of the main control unit and the input end of the wireless communication module, the main control unit is in bidirectional connection with the wireless communication module and the data storage unit, and the input end of the main control unit is electrically connected with the output end of the information collecting module. The vehicle-vehicle communication system based on the UWB has the advantages of being simple in structure, good in communication effect and the like, communication between vehicles is convenient, and the occurrence possibility of traffic accidents can be effectively reduced.

The invention discloses a transformer substation field operation target real-time monitoring method and system, and aims to solve the technical problem of insufficient transformer substation field operation safety control effect in the prior art. The method comprises the following steps: acquiring operation target position data by utilizing a pre-deployed target positioning device; selecting a video monitoring device by using a dynamic planning method according to the operation target position data, and obtaining an operation target tracking image; and acquiring an operation path of the operation target, and performing operation target state analysis and alarm according to the operation target position data, the operation target tracking image and the operation path to complete real-time monitoring of the operation target. The transformer substation field operation target real-time monitoring system can provide a transformer substation field operation target real-time monitoring effectand is convenient to deploy, low in cost and high in precision.

The invention discloses a precise distance measuring device based on UWB. The UWB signal adjustment module includes a signal differential coupling unit, a first microwave switch unit, a radio frequency power amplifying unit and a second microwave switch unit. The signal differential coupling unit and The first microwave switch unit is bidirectionally connected, the output end of the first microwave switch unit is electrically connected to the input end of the radio frequency power amplifying unit, and the output end of the radio frequency power amplifying unit is electrically connected to the input end of the second microwave switch unit. The invention has the advantages of simple and compact structure, low cost, can realize distance measurement based on UWB, has high distance measurement precision and wide measurement range.

The invention relates to an intelligent electric appliance positioning method, device and system, and a wearable device. When an intelligent electric appliance and a target node device perform ultra-wideband communication, the interaction information between the two is obtained, the distance information of the target node device and the intelligent electric appliance is calculated according to theinteraction information, corresponding node coordinates are established according to the interaction information and the distance information, the position information of the target node device relative to the intelligent electric appliance is obtained through the node coordinates, that is, the positional relationship between a user and the intelligent electric appliance, so the intelligent electric appliance is facilitated to perform corresponding adjustment operation according to the user position. The method is advantaged in that positioning is realized through ultra-wideband communication, as ultra-wideband communication employs narrow pulses with the short duration, good anti-multipath effect and penetration capability are achieved, ultra-wideband communication has better anti-interference ability, so the positioning method using the ultra-wideband communication technology has very high positioning accuracy.

The invention relates to a method and a sensor for detecting the relative sliding velocity between a plate and a mould in a stamping process. The method comprises the following steps of: (1) forming an area measured laser image on the measured surface of a steel plate; (2) acquiring the image information of continuously changed patterns and outputting the image information to a signal processor by using an image sensor; (3) analyzing the movement amount of a characteristic area by adopting a self-correlation image processing algorithm, and outputting displacement information; (4) outputting sliding velocity data by using a master control unit; (5) adjusting an acquisition frequency by using the master control unit; (6) obtaining a conversion function for a sliding velocity value and sliding velocity data: y=ax+b; and (7) obtaining an actual relative sliding velocity. By using the detection method and the sensor, the sliding velocity can be measured in a real-time and non-contact way in a plate stamping process. The method has high operability and can be used for determining the sliding velocity of the steel plate relative to the mould in plate stamping deformation by matching a corresponding test device, thereby meeting requirements on scientific research and test.

The invention discloses a building positioning method based on UWB (ultra-wideband) technology. The method includes TOA (time of arrival) distance estimate and weight selection by fuzzy logic, namely obtaining arrival time of a direct signal by weighting time of a first arrived signal and time of a strongest signal and calculating a weighting coefficient according to the fuzzy logic technology. Actual data indicates that positioning precision is highly enhanced by the method. Compared with traditional narrow bandwidth positioning system, the method has the advantages of high penetrating power, low power consumption, fine anti-multipath effect, high safety, low system complexity, high positioning precision and the like.

The invention discloses a children anti-loss wristband based on UWB technology. The children anti-loss wristband comprises a central processor, a UWB distance measuring module, a data transmission module, an intelligent reminding module, an LCD display module, an electronic lock, a storage module, a power supply, an LCD display device, a TTS, etc. The central processing module is unidirectionallyconnected with the power supply electrically. The power supply is used for supplying electric energy to the central processor. The intelligent reminding module comprises the TTS and a vibrator. The children anti-loss wristband based on the UWB technology has advantages of low UWB technical power consumption, high multipath effect resistance, high safety, high system complexity, high positioning precision, etc. Therefore the children anti-loss wristband becomes a hot commodity in wireless positioning technology in future. According to the children anti-loss wristband based on the UWB technology, the UWB technology is firstly applied in the anti-loss wristband, thereby realizing no dependence on other network nodes, realizing no restriction by the surrounding environment and no use cost, andovercoming a difficulty that distance measuring and positioning in a complicated environment can be difficultly finished in a traditional positioning system.

The present invention provides a broadband zero phase center high-precision antenna of a butterfly oscillator structure. The broadband zero phase center high-precision antenna comprises an antenna main radiation unit, a resonant cavity, a feed structure and a parasitic radiation structure. The antenna main radiation unit comprises a square PCB, an oscillator structure, a main radiation unit grounding plate and a regulation branchknot; the regulation branchknot is connected with the oscillator structure; the oscillator structure comprises four hexagonal radiation paster oscillators with hollowstructures and with dimensions; the corner of each hexagonal radiation paster oscillator comprises one feed angle and one wing tip angle opposite to the feed angle; the feed angles of the oscillatorsare integrally arranged at the centers of the square PCB and are connected with the feed structure; the side boundary of the feed angles of the adjustable oscillators are close neighbor and in parallel to each other; the wing tip angles of the oscillators are respectively arranged at the four corners of the square PCB to allow the oscillator structure to be a butterfly wing shape; and the parasitic radiation structure is round the antenna main radiation unit, and the lower portion of the main radiation unit grounding plate is connected with the resonant cavity. The broadband zero phase centerhigh-precision antenna of a butterfly oscillator structure has a high gain, a wide beam and a wide band, and is stable in phase center and high in anti-multipath effect capacity.

The invention discloses a different-rail lifting anti-collision protection device and method based on an UWB. The device comprises an UWB base station, an WUB label and an anti-collision control module; a power supply module and the anti-collision control module electrically connected are arranged in a control circuit sealing box; the UWB label is mounted on lifting machinery; the UWB base stationis arranged in anti-collision points of two sides of the lifting machinery or another lifting machinery; and the anti-collision control module comprises a main controller, and a signal display circuit, a RS422 communication circuit, a sound-light alarm circuit, an anti-collision control circuit and a remote output circuit electrically connected with the main controller. The different-rail liftinganti-collision protection device and method based on the UWB adopt different grades of alarm and lifting machinery motor deceleration and braking modes to realize the anti-collision safety work of the lifting machinery.

The invention relates to a nine-channel space spectrum super-resolution estimation monitoring and direction-finding mobile station system, which comprises a small double-cone omnidirectional monitoring antenna, a nine-unit direction-finding antenna, an amplifier, a monopole monitoring antenna, a nine-channel signal switching module, a filter combiner, am amplifier module, a nine-channel receiver, a monitoring and direction-finding controller, a DSP (Digital Signal Processor) processing module, an imbedded industrial computer, a GPS (Global Positioning System) antenna, a GPS module, a 3G (3rd Generation) antenna, a 3G router, a power supply module, a remote control unit, an exchanger, and the like. The system has the following advantages: the system achieves remote and automatic monitoring and direction-finding of radio signals; an imbedded computer system is integrally arranged so that the structure is compact and light; a direction-dinging assembly solves the coupling problem between the antenna arrays and prevents coupling and phase between unit antennas from being blurred; the structure is compact and light, and the spanning maintenance is convenient; the grid connection is flexible, and can support different wired / wireless network data transmissions; moreover, collection, compression coding, automatic task monitoring, statistic analysis and abnormal state alarm of wireless signals are realized.

The invention belongs to the technical field of fire-fighting communication, and particularly relates to a broadband wireless communication device for a fire-fighting robot. The broadband wireless communication device comprises a front-end transmission device and a rear-end receiving device. The front-end transmission device comprises a front-end power module, a front-end communication core board, a front-end video processing module, a front-end voice processing module, a front-end cavity filter, a front-end circulator, a front-end power amplifier and a front-end antenna. The rear-end receiving device comprises a rear-end power module, a rear-end communication core board, a rear-end voice processing module, a rear-end cavity filter, a rear-end circulator, a rear-end power amplifier and a rear-end antenna. According to the broadband wireless communication device for the fire-fighting robot, multi-channel audio and video transmission can be provided, high-speed data transmission is supported at the same time, and a communication protocol and a transmission system of the broadband wireless communication device are particularly suitable for multipath constructions like buildings with serious interference. According to the broadband wireless communication device, hybrid transmission of images, voices and data inside the same channel is supported, and the broadband wireless communication device has the advantages of being good in image real-time performance, high in voice compression ratio, short in data delay and the like.

An embodiment of the invention provides a UWB-based height-limiting height determination method, device and system. The UWB-based height-limiting height determination method comprises the steps of: acquiring a first distance between a target vehicle and a first UWB unit, wherein the first distance is determined through transmitting a distance measurement signal to the first UWB unit by a vehicle-mounted UWB unit; and acquiring a second distance between the target vehicle and a second UWB unit determined by sending the distance measurement signal to the second UWB unit by the vehicle-mounted UWB unit, and determining the height-limiting height of a road height-limiting frame according to the first distance and the second distance. By using the UWB-based height-limiting height determinationmethod and the system, the measurement of the height-limiting height of the road height-limiting frame can be realized; moreover, based on the features of insensitivity to channel attenuation, high penetrating performance, good anti-multipath effect and the like of the UWB , the interference in the distance measurement process can be reduced by the UWB, the measurement precision is improved, the height-limiting height of the road height-limiting frame can be accurately measured through using the UWB, the driving safety is ensured, and accidents are reduced.

Aiming at the tracking fuzziness problem of a Beidou B1C pilot channel QMBOC (6, 1, 4 / 33) signal, the invention provides and designs a B1C signal unambiguous tracking method based on a pseudo-exponential function, which comprises the following steps of: (1) carrying out carrier stripping and code correlation processing on the pilot channel QMBOC (6, 1, 4 / 33) signal; (2) the correlation value is sent to an exponential function module to be processed; (3) the discriminator processes an output value of the exponential function module; and (4) a discriminator result is processed by a loop filter to control a code loop NCO, and a local code phase is adjusted to form a closed loop. According to the invention, secondary peaks of correlation curves can be effectively eliminated, error locking points output by a discriminator are eliminated, correlation results of received signals and local signals are processed by using a pseudo-exponential function module, and unambiguous tracking of QMBOC (6, 1, 4 / 33) signals is realized. Meanwhile, compared with a traditional BPSK-like method, an SCPC method and an ASPeCT method, the B1C signal unambiguous tracking method based on the pseudo exponential function has better anti-multipath performance.

The invention provides a bee colony slope monitoring system based on ground surface inclination sensors, comprising: a plurality of monitoring node devices arranged on the slope surface at intervals of a certain distance; the monitoring node devices include micro-electromechanical system inclination sensors and batteries; The inclination sensor of the system is used to monitor the inclination change of the slope, and is also used to realize the sensor positioning to monitor the displacement change of the slope by using the signal time delay of the communication process; the data transmission equipment is arranged around the slope, and is used to transfer the The monitoring data is transmitted to the remote platform, and the monitoring data includes the slope change and displacement change of the slope; the remote platform is used to analyze the deformation of the slope according to the monitoring data. The invention can solve the technical problem that a surface inclination sensor and a displacement meter need to be used at the same time to monitor the deformation of the slope surface, and the monitoring system is relatively complicated.

The invention discloses an unambiguous tracking method for a high-order BOC modulation navigation signal. The unambiguous tracking method comprises the following steps: counting operation periods of subcarriers; a variable-subcarrier half-cycle counting accumulated value Accsc is increased, and initialization is carried out; counting the counting difference of the subcarrier half-cycle counts Cnt2sc of the two FTF time mark signals as an incremental quantity, and accumulating the Accsc; continuously comparing the Accsc with the updated half-cycle fuzzy value Cntsc of the subcarrier; setting a locking state; if continuous equal times reach a lock-in threshold value, entering a lock-in state, replacing an original subcarrier half-cycle fuzzy value Cntsc with Accsc, and outputting a subcarrier observation value as a distance measurement observation value; setting a lock losing state; and if continuous unequal times reach a lock losing threshold value, entering a lock losing state, re-initializing the Accsc, and at the moment, outputting a code observation value as a distance measurement observation value. According to the method, the problem that traditional subcarrier tracking is fuzzy is solved, a good anti-multipath effect and stable high-precision distance measurement observed quantity can be obtained, and therefore the positioning precision is improved.

The invention relates to a multipath interference elimination method, a channel impulse response frequency spectrum estimation method, a multipath interference elimination device, a channel impulse response frequency spectrum estimation device and a receiver. The multipath interference elimination method comprises the following steps: acquiring a cross-correlation signal frequency spectrum of a GNSS input signal and a receiver local signal; weighting the cross-correlation signal frequency spectrum to obtain a weighted frequency spectrum; performing sliding window summation on the weighted frequency spectrum to obtain a sliding window summation frequency spectrum; performing normalization processing on the sliding window summation frequency spectrum to obtain a channel impulse response frequency spectrum; and converting the channel impulse response frequency spectrum to a time domain to obtain a time domain waveform of the channel impulse response, and carrying out code phase deviation identification on the time domain waveform to obtain a code phase deviation of a direct path so as to eliminate multipath interference. According to the invention, the code phase deviation can be accurately estimated after the multipath signal is overlapped with the direct incidence path.

A precise GNSS directional antenna includes a reflection cavity, a radiation lower patch, a radiation upper patch, four L-shaped metal feed probes, a first supporting column, a second supporting column and a choke groove. The reflection cavity is a hollow cylinder of which a bottom surface is closed, height of the reflection cavity is a little bit lower than the radiation upper patch and higher than the radiation lower patch, the radiation lower patch is higher than the L-shaped metal feed probes and concentrically connected with an inner bottom surface of the reflection cavity by the second supporting column, and the radiation upper patch is concentrically connected with the radiation lower patch by the first supporting column. The four L-shaped metal feed probes are installed on an inner bottom surface of a transmitting cavity and uniformly distributed on same circle. The bottom surface of the reflection cavity is installed on the choke groove, the choke groove is a pyramidal structure, height of four choke rings decreases progressively from the inside to the outside, and each choke ring has equal depth and equal interval. The precise GNSS directional antenna has wider beam coverage capability and strong multi-path interference resistance in low elevation direction, and is suitable for a precise positioning system.

The invention relates to a UWB technology-based positioning system architecture and a positioning method, and the positioning system architecture comprises a UWB positioning tag which is arranged on a target needing to be positioned; several UWB positioning beacons fixedly arranged in a chemical plant area according to a preset rule, wherein each UWB positioning beacon comprises a battery used for supplying power, and the UWB positioning tag and the UWB positioning beacons are in wireless positioning communication through UWB signals so as to obtain position information of the UWB positioning tag relative to the UWB positioning beacons; a communication base station covering the positioning areas of the plurality of UWB positioning beacons and used for wirelessly receiving the position information of the plurality of UWB positioning labels in the coverage areas; and a positioning engine in communication connection with the communication base station and used for receiving the position information of each UWB positioning tag and carrying out position calculation on the position information so as to obtain the position coordinate of each UWB positioning tag. The positioning system architecture provided by the invention does not need wiring and is high in positioning precision.

The invention discloses a frequency offset estimation method and device in a mobile communication system, which is characterized in that it includes the following steps: receiving training sequence (midamble) data r of a time slot; performing channel estimation to obtain the original frequency offset-affected The channel impulse response hfreq; detect the components of the transmitted midamble data; estimate the channel impulse response h that is not affected by the frequency offset; estimate the received midamble data r that is not affected by the frequency offset; perform maximum likelihood frequency offset estimation, and output the estimated frequency Partial. The invention can accurately estimate the frequency deviation, can adapt to a system composed of multiple subcodes, such as the training sequence system of TD-SCDMA, has good anti-multipath performance, and is simple and easy to implement.

The invention discloses an intelligent prison early warning management system. Th system comprises an anti-disassembly wristband body, a police card and a material label; a monitoring module, a wristband alarm module, a prisoner access control module, a prisoner positioning module and an information memory are arranged in the anti-disassembly wristband; a wristband communication module is arrangedin the anti-disassembly wristband; and the monitoring module, the wristband alarm module, the prisoner access control module, the prisoner positioning module and the information memory are in signalconnection with an external positioning base station through the wristband communication module. According to the system of the invention, the real-time position of a prisoner wearing the anti-disassembly intelligent wristband can be displayed; the police card is provided for a policeman. The big data-based intelligent supervisory system integrating an existing prison intelligent terminal, a high-definition digital monitor, an intelligent access control unit and the like, has excellent anti-interference performance and anti-multipath effect, still has high positioning precision in a complex indoor environment, and provides reliable real-time position data for a monitoring center.