46results about How to "Reduce communication bit error rate" patented technology

The invention provides an indoor positioning method adopting visible light and inert composition. A mobile carrier can detect a visible light signal in a process of moving in a room. The indoor positioning method comprises the following steps: judging whether the mobile carrier is positioned in a visible light strong coverage region according to a light intensity threshold value; if a light intensity value is less than the light intensity threshold value, directly taking a position estimation value acquired by an inert device as carrier positioning information; if the light intensity value is greater than or equal o the light intensity threshold value, calculating the position estimation value according to the visible light signal, subtracting the position estimation value acquired by the inert device from the position estimation value calculated according to the visible light signal, and performing Kalman filtering on an obtained difference value to obtain a drift error of the inert device, wherein the drift error is used for correcting the inert device, and the corrected position estimation value of the inert device is used as the carrier positioning information. According to the indoor positioning method, the influence caused by a cover blind area and a shadow in a visible light positioning process can be effectively avoided, and the shortcoming that the error of the inert device is accumulated along the time is overcome; continuous automatic high-precision indoor positioning is realized.

The invention discloses an OFDM (Orthogonal Frequency Division Multiplexing) system parametric channel estimation and equalization method based on compressed sensing technology. The channel estimation method comprises the following steps: 1) an OFDM frequency domain at a pilot subcarrier receives data, and parameter estimation is carried out on the channel based on a channel parametric model: firstly, according to a MDL (Minimum Description Length) criterion, a multipath number estimation value L<^> of the channel is obtained; then, the ESPRIT (estimation of signal parameters by rotational invariance techniques) technology is used for estimating delay parameters for each path, and multipath delay estimation values tau<^>=[tau<^>1, tau<^>2,..., tau<^> < L<^>>] are obtained; and 2) a parameter estimation result is used for building a redundant dictionary matrix, and a channel response estimation value is solved through a BPDN algorithm. Based on parametric channel modeling, the signal parameter estimation technology is combined with a compressed sensing frame, the channel estimation precision and the communication efficiency are improved, and the communication bit error rate is reduced. Compared with the traditional channel estimation method, the method of the invention has obvious performance advantages.

The invention discloses a dolphin click simulating underwater acoustic communication method based on time-frequency spectrum translation. At a transmitting end, the time-frequency spectrum contour curve of a real dolphin whistle signal is translated in the vertical direction for loading digital information; signal combination is performed based on a modulated contour curve for obtaining a bionic communication signal; and an original whistle signal is added in front of the bionic communication signal as a synchronization signal, thereby forming a transmission signal frame. At the receiving end, the starting position of the bionic communication signal is determined through synchronization signal correlation; multiplication filtering and Fourier transform information demodulation or modulation are performed on the received bionic communication signal, thereby realizing information decoding. The bionic communication method has no specific requirement for characteristic and number of real dolphin whistle signal sample, and the combined coding signal accords with the characteristic of the dolphin whistle signal. Therefore the dolphin click simulating underwater acoustic communication method has high concealing performance.

The invention belongs to the field of bionic underwater acoustic communication, and particularly relates to a dolphin whistle imitated underwater acoustic communication method based on time-frequency spectrum extension and retraction. The method provided by the invention comprises the steps of transforming binary information into decimal information; extracting a time-frequency spectrum profile curve of real dolphin whistle signals; carrying out power amplification on frame signals, and then sending the amplified frame signals to an underwater acoustic channel through a transducer; receiving the signals through a hydrophone; and carrying out synchronization on the received signals. The technical scheme provided by the invention has no special requirements for characteristics and the quantity of selected real dolphin whistle signal samples, so that the dolphin whistle signal samples can flexibly selected according to a sea area to which underwater acoustic communication is applied and specific communication requirements. A mode of enabling the time-frequency spectrum profile curve of the real dolphin whistle signals to extend and retract is adopted in information modulation, and synthesized coded signals conform to characteristics of the dolphin whistle signals, thereby having very high concealment performance.

The invention relates to a system for detecting the address of a coke oven and recognizing the heat number automatically, wherein a system for detecting and positioning the address of the system and a data communication system are executed separately and independently, the system for detecting and positioning the address consists of a ground station and an on-vehicle station and adopts a high temperature resistant, corrosion resistant and coding positioning impedance matching cable technique to achieve the address detection and positioning of four onsite locomotives, and the positioning system adopts a command based on a USS protocol and a PID control algorithm to control the running of a frequency transformer; and the data communication system adopts a wireless communication module and a wireless spread spectrum communication mode to achieve the data communicates between the four locomotives and between the four locomotives and a host computer server. The system achieves the precise positioning and anti-interference data stable communication of the onsite four locomotives; the coal loading weight can be intuitively displayed on an automated operation management client interface through a coal tower weighing system; and the system greatly reduces the cost, reduces the maintenance workload and has good safety performance.

A magnetic field modulated multi-target X-ray source for spatial X-ray communication comprises a cathode structure, a focusing groove, an electron emission source, a glass shell, a Kovar alloy ring, afocusing electrode, a modulation electromagnetic device, a multi-target metal anode, and a transmission window. The cathode is connected with a negative high voltage, the electron emission source isdisposed in the focusing groove, the glass shell and the focusing electrode are in tight coupling by the Kovar alloy ring, the modulation electromagnetic device is disposed near the multi-target metalanode, the multi-target metal anode is grounded, and one side is facing a focus channel and the other side is plated on the transmission window layer. The magnetic field modulated multi-target X-raysource utilizes a fast-responding high-frequency modulation magnetic field, changes the electron motion trajectory to bombard the multi-target metal anode, excites characteristic X-rays of different energies, and uses characteristic X-rays of different energies as signal transmission carriers to solve the problem that the existing intensity modulation X-ray source technology is less in loading symbol signal and low in communication rate. The magnetic field modulated multi-target X-ray source has the advantages of multiple types of loading symbol signals and large communication rate.

The invention discloses a communication signal detection method based on adaptive stochastic resonance. The problem that the system structure parameters and the calculation step size of the stochasticresonance in the prior art are difficult to be selected is solved. The method comprises the following steps of: inputting a communication signal, determining parameters of the particle swarm and initializing the parameters; sampling the received signal in time; establishing a model of adaptive stochastic resonance system; calculating fitness of stochastic resonance system by particle swarm optimization algorithm; determining whether the iteration is terminated; outputting detected signal. A particle swarm is established by taking a stochastic resonance system as a model, Particle Swarm Optimization (PSO) is used to obtain the optimal structural parameters of the adaptive stochastic resonance (ASR) system. The output signal-to-noise ratio (SNR) and bit error rate (BER) are used as fitnessvalues. The weak signal under noise background can be detected optimally. The invention greatly improves the output signal-to-noise ratio, reduces the bit error rate, and is used for digital signal detection.

The invention relates to a limited feedback precoding method based on a short wave multi-antenna system. The limited feedback precoding method specifically comprises the following steps that (1) a codebook is designed; (2) a rotating Grassmann codebook under a short wave multi-antenna system channel is obtained, (3) a sending end inputs a code stream, modulates the code stream, and multiplies the modulated code stream by a precoding vector w to generate a sending signal vector; (4) a receiving end conducts channel estimation to obtain an instant channel matrix H; (5) according to the rotating Grassmann codebook obtained in the step (2), the optimum codon w is selected, a serial number corresponding to the w is returned to the sending end through a feedback channel, and the sending end updates the precoding vector w according to the serial number; (6) the receiving end adopts the maximum likelihood method for conducting signal detection and generates an output code stream after demodulation. Compared with the prior art, the correlation of the short wave channel is considered, the bit error rate of short wave multi-antenna system communication is lowered, and the signal transmission reliability is improved.

The invention relates to a system and method for performing voice encryption communication between communication terminals and aims to solve a technical problem that correct demodulation can not be performed at a receiving end due to weakening and cutting processing. Through employing a first voice coding codec, an application processor and a second voice codec sequentially connected with an audiointerface of a mobile terminal, the second voice codec is connected with the communication terminals, the application processor includes a noise reduction module, a voice characteristic extraction / synthesis module, an encryption / decryption module and a modem module sequentially connected with the first voice codec, and the modem module is used for modulating data flows after compression and demodulating encrypted data flows. The modulated data flows can pass through a voice channel, the problem is better solved, and the system is applied to the voice communication technology.

The invention provides an underwater robot oriented underwater communication method. The underwater robot oriented underwater communication method comprises the steps of building an underwater robot oriented underwater communication network topology and an underwater communication network protocol; detecting whether an electric field signal exists in communication between the underwater robots by utilizing an underwater communication network channel detecting device based on the underwater robot oriented underwater communication network topology and the underwater communication network protocol; detecting the channel state by an underwater electric field communication data link layer designed based on a CSMA / CA (Carrier Sense Multiple Access with Collision Avoidance) protocol before an underwater robot requests to send data; after determining that the channel is idle, sending data in time; and if the channel is busy, entering a random back-off process, wherein the random back-off process is designed by adopting a truncated binary exponential back-off algorithm. The underwater robot oriented underwater communication method has the advantages of high reliability, high accuracy in channel state detection, convenience in node increase and decrease, low communication interference, good environment adaptability, compact volume and etc.

This invention relates to a method for increasing communication reliability of RF identifying system including: 1, adding a direct sequence spread spectrum circuit in labels in the reverse link between the communications of a label and a card reader and adding a spread spectrum code and a de-spread circuit same to the direct sequence spread spectrum circuit in the card reader, 2, the baseband data to be sent by the label is engaged in direct sequence spread spectrum by the preset spread code and the spread circuit, 3, modulating the baseband data after being spread onto a carrier, 4, the label feedback signal is reflected to the reader via the antenna, 5, said reader demodulates the carrier reflected by the label, 6, said reader de-spreads the baseband signal by the spreading code in conformity with the label to get the baseband data sent by the label.

The invention discloses a ray position modulation communication system and a communication method, the ray position modulation communication system comprises an information source, a regulation and control circuit, a signal generation device, a signal receiving device and a demodulation circuit which are sequentially arranged along a signal transmission direction, the signal generation device comprises a radioactive source and a base, and the radioactive source emits rays with strong penetrability, wherein a plurality of positioning positions are arranged on the base, and the radioactive source is driven by the regulation and control circuit to be switched among the plurality of positioning positions; according to the initial electric signal, the radioactive source is driven to move and switch among a plurality of positioning positions, and rays emitted by the radioactive source at different positioning positions form ray signals; the signal receiving device comprises a plurality of ray detectors which are in one-to-one correspondence with the positioning positions in the ray transmission direction, receive ray signals, convert the ray signals into coded electric signals, demodulate the coded electric signals and then output the coded electric signals. According to the invention, based on ray position coding, code element types are more, the communication rate is improved, andthe communication error rate is reduced.

The invention discloses a short guard interval multi-carrier shallow sea underwater acoustic communication method and system. The method comprises the following steps: estimating time delay spread of a channel according to a preamble sequence of a data frame, wherein the data frame comprises the preamble sequence and a data block; a plurality of analysis time windows are determined according to the time delay extension, and the initial positions of the analysis time windows are different; demodulating the data block under each analysis time window to obtain a demodulation result corresponding to each analysis time window; determining the bit error rate of each demodulation result; and taking the demodulation result with the minimum bit error rate as target communication data. According to the method, a plurality of parallel analysis time windows are adopted to analyze and process the data blocks, and the optimal analysis time window is selected through the bit error rate to eliminate inter-carrier interference (ICI), so that the communication bit error rate of the system is reduced when the guard interval is short (the communication rate is high).

The invention provides a burst type underwater acoustic communication method. Binary information to be transmitted is divided, a minimum quantization interval of a frequency difference is calculated according to the optimal transmitting frequency range of a transmitting transducer, the divided binary information is respectively used for calculating a frequency difference and a time difference between a reference low band signal and a delay and frequency difference load signal, and a delay difference and the frequency difference are modulated between the reference low band signal and the delayand frequency difference load signal to complete the burst type underwater acoustic communication modulation based on time-frequency combination. After the synchronization of a receiving end is completed, each chip is synchronized again by using the reference low band signal and a local reference signal, signal interception is completed, the delay difference and the frequency difference carried ineach intercepted chip are estimated, and the difference is demodulated based on the minimum quantization interval during the modulation to obtain modulation information. The burst type underwater acoustic communication method provided by the invention is simple and easy to operate and high in reliability, underwater multipath and interference can be resisted according to the special structure ofthe frame signal.

The invention relates to a discrete Fourier transform extended orthogonal time-frequency spatial modulation method, which comprises the steps of performing DFT precoding processing and time delay Doppler domain mapping processing on a digital baseband signal, inputting the digital baseband signal into an OTFS modulator for receiving and transmitting, and simultaneously performing time delay Doppler domain inverse mapping processing and IDFT decoding processing on a received signal to realize modulation and demodulation. Compared with the existing waveform OFDM, the DFT-s-OFDM can reduce the bit error rate under the high Doppler spread channel and can reduce the peak-to-average power ratio of the transmitted signal at the same time.

An MBUS host transmitting circuit is disclosed in the invention, and comprises an optocoupler isolation module, a change-over switch, a voltage conversion circuit and a boost chip circuit; the input end of the optocoupler isolation module is connected with a host, and the output end of the optocoupler isolation module is connected with the control end of the change-over switch; the output end of the change-over switch is connected with the control input end of the voltage conversion circuit, the feedback output end of the voltage conversion circuit is connected with the output voltage control end of the boost chip circuit, and the input end of the boost chip circuit is connected with a first power supply; and the output end of the boost chip circuit is the signal output end of the MBUS host sending circuit. The invention further discloses a signal sending method and an MBUS bus system. According to the invention, the change rate of the rising edge and the falling edge of the communication waveform is improved, so that the communication rate is improved, and the communication error rate is effectively reduced.

The invention relates to an X-ray source for spatial X-ray communication based on energy load signals; a cathode assembly of the X-ray source comprises an electron emission source, a power supply rod,power supply rod insulation ceramic, a cathode cover and a cathode barrel; a focusing electrode assembly comprises a focusing electrode diaphragm and a focusing electrode barrel; an anode assembly comprises an anode diaphragm and an anode barrel and is connected with a multi-target transmission window assembly through the anode barrel; an electric field modulation assembly comprises a multi-section electrode and an electrode bracket; and the multi-target transmission window assembly comprises metal target materials, a transmission window and a target welding ring. According to the X-ray source for spatial X-ray communication based on energy load signals in the invention, a fast-response high-frequency pulse modulation electric field modulation assembly is utilized to generate a modulationelectric field, the electronic motion track is changed, the different metal target materials on the multi-target transmission window assembly are bombarded, and characteristic X-rays with different energy are generated. The characteristic X-rays with various kinds of energy are used as code elements, so that rapid X-ray spatial communication based on energy load signals is achieved. The X-ray source in the invention is high in modulation speed, large in number of the loadable code elements, high in signal-to-noise ratio, low in error rate and high in communication speed.

The invention discloses a 3G network based smart home gas stealing preventing wireless gas meter reading system, belonging to gas meter reading systems in the technical field of smart homes and aiming to provide a 3G network based smart home gas stealing preventing wireless gas meter reading system with higher reliability and real-time property. The problem that the installation stability of magnetic steel in counters of existing gas meters is poorer can be solved. The system comprises gas meters, MSP430F149 microprocessors, Si4432 modules, concentrators and a CPU (central processing unit), wherein an inductor identification circuit in each gas meter is electrically connected with each MSP430F149 microprocessor; each MSP430F149 microprocessor is electrically connected with each Si4432 module; each Si4432 module is connected with each concentrator by a wireless network; each concentrator is connected with the CPU by a 3G network. The gas meter reading system is suitable to use in smart homes.

The invention belongs to the technical field of space communication, and discloses a method for realizing navigation and communication information fusion based on multiple characteristic signals. The method comprises the following steps: acquiring information to be transmitted; fusing the information to be transmitted to obtain fused information; modulating a characteristic signal according to the fusion information, wherein the characteristic signal is an X-ray characteristic energy spectrum signal; emitting an X-ray characteristic energy spectrum signal; receiving an X-ray characteristic energy spectrum signal; discriminating the received X-ray characteristic energy spectrum signal; and separating and extracting the X-ray characteristic energy spectrum signal. Compared with a traditional method of modulating '0' and '1' signals based on intensity or existence of signals, fusion communication of the two kinds of signals is achieved under the condition that the power of communication equipment is not increased, the problems that in the prior art, the communication efficiency is low and the bandwidth is narrow are solved, fusion of more information can be achieved by increasing the types of X-ray characteristic energy spectrums, and the communication efficiency is improved. The bandwidth of a space channel is greatly expanded, and the use efficiency of a space link is improved.

The invention discloses a 3G network based smart home wireless smart electric meter reading system, aiming to provide a 3G network based smart home wireless smart electric meter reading system with higher reliability and real-time property. The system comprises smart electric meters, MSP430F149 microprocessors, Si4432 modules, concentrators and a CPU (central processing unit), wherein each smart electric meter comprises a metering module, a microprocessor, a signal encryption module and a signal output module, which are electrically connected in sequence; the signal output module is electrically connected with each MSP430F149 microprocessor; each MSP430F149 microprocessor is electrically connected with each Si4432 module; each Si4432 module is connected with each concentrator; each concentrator is connected with the CPU. The smart electric meter reading system is suitable to use in smart homes.

The invention relates to a carrier digital pulse interval modulation C-DPIM (carrier digital pulse interval modulation) power line data communication method and a transceiver device. Use linear sweep SSC spread spectrum carrier or 50KHZ-535KHZ narrowband carrier signal sequence to generate DPIM pulse, and use pulse interval to realize DPIM symbol encoding. The duration of the carrier signal is equal to or less than the time width of a basic time slot (slot) describing the time interval between two pulses in the DPIM system. Impulse preamble is introduced as a synchronization signal for transmitting data blocks to prevent error propagation. And using the single chip microcomputer to realize the carrier digital pulse interval modulation (C-DPIM) communication method, developed the power line carrier communication interface transceiver device, in the power line network environment where the correct communication cannot be realized by using INTELLON SSC P300 transceivers and methods, using C - The DPIM communication method realizes the ideal power line carrier communication.

The invention discloses a ray position modulation communication system and a communication method, which include an information source, a control circuit, a signal generating device, a signal receiving device and a demodulation circuit sequentially arranged along the signal transmission direction, and the signal generating device includes a radiation source and a base , the radioactive source emits rays with strong penetrating properties. There are multiple positioning positions on the base, and the radioactive source is switched between multiple positioning positions under the drive of the control circuit; according to the initial electrical signal, the driving radioactive source is Move and switch between multiple positioning positions, and the radiation emitted by the radioactive source at different positioning positions forms a radiation signal; the signal receiving device includes multiple radiation detectors, and the multiple radiation detectors are aligned with the multiple positioning positions in the direction of radiation transmission. One-to-one correspondence, receiving the ray signal, converting the ray signal into a coded electrical signal, and outputting it after demodulation. The invention is based on the coding of the ray position, has more types of code elements, helps to improve the communication rate, and at the same time reduces the communication bit error rate.

The invention relates to a coke oven address detection and furnace number automatic identification system. The address detection and positioning system of the system is executed independently from the data communication system. The address detection and positioning system is composed of a ground station and a vehicle-mounted station, and adopts high temperature resistance and corrosion resistance. , Code positioning impedance matching cable technology to realize the address detection and positioning of the four major locomotives on site. The positioning system uses commands based on the USS protocol and PID control algorithm to control the operation of the frequency converter; the data communication system uses wireless communication modules. Data communication is carried out between the four major vehicles, between the four major vehicles and the host computer server. The system realizes the precise positioning of the four locomotives on site and the stable communication of anti-interference data; the coal loading weight can be intuitively reflected on the automatic operation management client interface through the coal tower weighing system; the system greatly reduces the cost and maintenance workload , Good safety performance.

The invention discloses a device and a method for detecting a working fluid level depth of an oil well based on an audio frequency sound wave electroacoustic system. The device comprises a signal conditioning system arranged on the ground, a standard sound source, a multichannel high-power D class digital power amplifier, a first electroacoustic device, a second electroacoustic device, a sound-wave combined waveguide pipe and a wellhead sound wave receiver, wherein a two-path or multi-path audio frequency signal is generated by the standard sound source; the two-path or multi-path audio frequency signal is amplified through the power amplifier and then is fed into each electroacoustic device, so that an audio frequency sound-wave signal is generated; the audio frequency sound-wave signal is coupled and then is fed into the well; after the signal is reflected by the working fluid level of the oil well, the time difference between the echo signal and the fed-in sound-wave signal is measured and then the depth of the working fluid level depth of the oil well is calculated. According to the invention, the theoretically limitlessly amplifying the sound wave power can be realized through the sound wave coupling tube, and meanwhile, the adopting frequency can be dynamically changed according to the underground voice frequency characteristics, so that the system can adapt to various application conditions of different depths and well conditions.

The invention discloses an intelligent household gas meter wireless meter-reading system based on 3G network, belongs to the gas meter meter-reading system in the technical field of intelligent household, aims to provide the intelligent household gas meter wireless meter-reading system based on the 3G network and having higher reliability and real-time performance, and can solve the problem that magnetic steel in a counter of a conventional gas meter has relatively poor installation stability. The system includes a gas meter, an MSP430F149 microprocessor, an Si4432 module, a concentrator and a central processing unit; an inductor identification circuit in the gas meter is electrically connected with the MSP430F149 microprocessor, the MSP430F149 microprocessor is electrically connected with the Si4432 module, the Si4432 module is connected with the concentrator through the wireless network, and the concentrator is connected with the central processing unit through the 3G network. The gas meter wireless meter-reading system is suitable for intelligent household.