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 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 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 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.

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.

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 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 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.