62 results about "NO CARRIER" patented technology

An information access system comprises a reader / writer for continually transmitting an ID request signal at a first frequency and being continuously ready to receive an RF signal at a second frequency, and an active contactless information storage device having a receiver for sensing a carrier of an RF signal at the first frequency, and a transmitter for transmitting a response signal at the second frequency when the ID request signal is received. When the receiver senses a carrier of an RF signal at the first frequency in a particular predetermined period, the receiver receives further the ID request signal, and, in response to the ID request signal, the transmitter transmits a response signal at the second frequency carrying an ID of the storage device stored. In the carrier sensing, the controller causes the receiver to be in an active state and the transmitter to be in an inactive state in the predetermined periods. When the receiver attempts to sense a carrier of the RF signal at the first frequency in a particular predetermined period but detects no carrier, the controller controls the receiver and the transmitter to maintain the inactive state during a sleep period between the particular predetermined period and the subsequent predetermined period.

A simplified spread spectrum demodulator uses a frequency detector to demodulate a modulated spread spectrum signal to obtain successive chip values. A correlation unit correlates the successive chip values with fixed sequences of correlation coefficients to generate correlation values. A decision circuit selects one of the correlation values to decide what symbol the spread spectrum signal represents. The correlation coefficients are obtained by applying the same modulation method as used to modulate the spread spectrum signal, and then the same demodulation method as used by the frequency detector, to the sequences of chips representing different symbols. Since synchronous detection is not employed, no carrier recovery circuit is needed.

An information access system comprises a reader / writer for continually transmitting an ID request signal at a first frequency and being continuously ready to receive an RF signal at a second frequency, and an active contactless information storage device having a receiver for sensing a carrier of an RF signal at the first frequency, and a transmitter for transmitting a response signal at the second frequency when the ID request signal is received. When the receiver senses a carrier of an RF signal at the first frequency in a particular predetermined period, the receiver receives further the ID request signal, and, in response to the ID request signal, the transmitter transmits a response signal at the second frequency carrying an ID of the storage device stored. In the carrier sensing, the controller causes the receiver to be in an active state and the transmitter to be in an inactive state in the predetermined periods. When the receiver attempts to sense a carrier of the RF signal at the first frequency in a particular predetermined period but detects no carrier, the controller controls the receiver and the transmitter to maintain the inactive state during a sleep period between the particular predetermined period and the subsequent predetermined period.

The invention belongs to the technology filed of wireless communication, relating to a method for jointly demodulating MSK (minimum shift keying) and DSSS (direct sequence spread spectrum) and a demodulator thereof. The demodulator comprises an error information obtaining module, a match filter module, a synchronous information trapping module, a demodulating module and a tracking module; and the method for jointly demodulating MSK and DSSS comprises the following steps of: (1) obtaining error information, (2) matching and filtering the error information, (3) trapping synchronous information, (4) demodulating, (5) tracking, or the like, and sending demodulation results to parent process so as to complete communication process. The invention has the advantage of better frequency compensation ability, thereby, solving the problems that a method for dispreading and demodulating direct sequence spread spectrum signals needs to be frequency offset estimated, complex extraction of PN code synchronization and bit synchronization, etc. Compared with the existing dispreading and demodulating method, the invention is simple as needing no carrier recovery module nor bit timing module, and is applicable to the wireless communication system.

Systems and method for determining if a network of a call page has been ported to another network. The mobile communications network associated with a received call page is determined based on caller identification (CID) included in the call page and information of local exchange codes and associated mobile carriers stored in local memory of the mobile device. The method determines if the mobile communications network associated with the received call page is valid with regard to an exceptions list. Next it is determined if the determined mobile communications network associated with the call page matches the mobile communications network associated with the mobile device based on the validity determination. The exceptions list identifies phone numbers that have been ported to a mobile communications network that is different that the determined network.

Radio communication devices receive timing reference pulses from a timing generation device and can acquire synchronism based on the received pulses. Accordingly, even on the UWB radio communication system, where there is no carrier as exists in the conventional radio communication systems, there is no need to add a redundant preamble signal ahead of transmitted information in order to acquire initial synchronism. In order to receive an asynchronous signal, there is no need to perform detection for a very long time to find whether the signal is present or absent. The application of an access control system according to the present invention to UWB radio communication implements high speed asynchronous radio communication.

Disclosed is a magnetic bearing system capable of simplifying a demodulation operation and reducing a processing load associated with a magnetic levitation control. A carrier signal having a frequency fc is apply to a sensor through a filter. The sensor operates to modulate the carrier signal, and a difference amplifier operates to calculate a difference between the amplitude-modulated signal FAM (t) and a sensor reference signal Fstd (t). An A / D converter operates to A / D convert a difference signal Fsub (t) output from the difference amplifier to a discretized sensor signal. In the A / D conversion, a sampling frequency fs is set to satisfy the following relation: fc: fc=n·fs or fc=fs / 2 (n is a natural number). Thus, the discretized sensor signal includes no carrier wave, and therefore a demodulation operation which has been previously essential can be simplified.

The invention relates to a method for CPU processing and receiving data in a radio frequency contactless smart card. When a card reader is communicated with the radio frequency card, the radio frequency card receives the data sent by the card reader, and the received data is sent to a CPU for processing after the demodulation and decoding. While a coding mode is a miller code in the protocol of the contactless smart card which is in line with ISO14443 type A; a carrier wave is modulated by the miller code, and each code cell or character almost has the pause of the carrier wave. When in pause of the carrier wave, a chip has no carrier wave signal, and the chip has no energy of an external power supply and also possibly has no clock. Therefore, the data (characters) which is output to the CPU after the decoding are difficult to process by the CPU. The invention uses a more innovative method that when the next received byte is demodulated or decoded after every byte is decoded, the CPU is worked at the proper frequency to rapidly process and receive the last byte, thus simultaneously realizing the receiving and the processing of the data.

There is provided herein a system and method for automatic configuration of data routings for use with electronic data such as phone calls, faxes, etc. In the preferred embodiment, when more than one carrier might potentially terminate the transmission, the carriers are ordered based on some screening criterion (e.g., transmission price). Data transmissions are then assigned to the carriers based on the sorting order, with the second place and lower carriers (e.g., the higher priced carriers) not being selected unless the first carrier cannot complete the transaction. The switch instructions necessary to implement this scheme are generated automatically.

The application discloses a label anti-collision method and an active radio frequency identifying label. The method is applied to the active radio frequency identifying label. The label anti-collision includes steps of S11, sending data information; waiting to receive an answer signal responding to the data information; if the answer signal is not received, entering step S12; S12m detecting a carrier wave; if the carrier wave is detected, entering step S13; S13, delaying the preset time, and detecting the carrier wave again; S14, if the carrier wave is not detected, entering step S11; if the carrier wave is detected, entering the step S13. By comparing with the traditional ALOHA algorithm that the data information is sent after delaying the preset time, it is obvious that the label anti-collision method further reduces the collision ratio of the ALOHA algorithm and improves the communication efficiency since the carrier wave is detected after delaying the preset time, and the data information of the next time is sent under the condition of no carrier wave detected.

The invention provides an online testing method for capture trajectory using high precision aerodynamic models, comprising of using the online testing flow of capture trajectory of high precision aerodynamic models, the calculation method of the interference amount of the external load of the carrier, the calculation method of the angle of attack induced by the external load, the multi-dimensionalinterpolation method of the aerodynamic force, and the high precision aerodynamic model construction method for the external load. The main features of the online testing method for capture trajectory using high precision aerodynamic models are as follows: when solving the six-degree-of-freedom equation, the aerodynamic force including the influence of the induced angle of attack angle is used toperform the trajectory solution rather than the aerodynamic force directly measured during the testing as to the aerodynamic force of the external load; and the aerodynamic force when the carrier isin the interference minus the aerodynamic force when the external load has no carrier interference. The online testing method for capture trajectory using high precision aerodynamic models effectivelysolves the problem of aerodynamic distortion caused by the movement of the external load relative to the carrier movement during the capture trajectory testing, and greatly improves the accuracy of the capture trajectory testing data.

The invention discloses a data transmission method, a sending terminal, a reception terminal and a data transmission system. The method includes setting a plurality of standby channels in advance, sending a data transmission request to the reception terminal directly using a determined current channel when the sending terminal has data transmission demand, using the channel for data transmission when there is response, switching to another standby channel to execute the previous steps when there is no response until preset condition (an available channel is determined, data transmission is completed or processing is overtime) is met. A data transmission request is sent directly to a current channel when data transmission demand exists, and no carrier sensing before data transmission is needed. When the current channel is busy or has interference, time-delay waiting is not necessarily, and another available channel is determined from other standby channels to transmit data. Real-time and anti-interference performance of data transmission is effectively guaranteed.

The present invention concerns a method and a system for accelerating fault recovery in a redundant, tree structured local area network. The invention is used to define some of the LAN ports, which are, for example, used to connect the switch (SW) into the IP router, as critical ones. Likewise, some other LAN ports, used to connect the IP hosts to said switch (SW), are defined as dependent of the critical links. If a critical LAN port or corresponding link is found to be non-functional, e.g. no carrier sensed, all LAN ports or corresponding links depending on it are declared as non-functional. The declaration is done at link level in a way which allows the device(s) or ports connected to the other end of the link to notice that the link is not in use anymore to carry traffic.

The invention discloses a carrier-free information hiding method for a big data Chinese text, and the method comprises: firstly carrying out preprocessing of the big data Chinese text, and mainly comprises word segmentation of the text, calculation of the word frequency and TF-IDF feature information of words after word segmentation, and LDA topic model clustering of the text; then, the sender segments the secret information, converts the secret information into keyword IDs through a word index table, and searches a text containing secret information keywords in the big data text; and, secondly, the searched text is used as an index label according to theme distribution of the corresponding text and TF-IDF characteristics of keywords in the corresponding text, meanwhile, a random number isintroduced to control the sequence of the secret information keywords, and finally, the random number and the index are used as labels together to be encrypted and sent to a receiver. Experiments show that the method improves the concealment and security of secret information while improving the concealment capacity.

The invention relates to a phase-locked loop frequency modulation circuit capable of achieving continuous modulation. The circuit comprises a controlled unit, a control unit, a detection unit, and a mode switching unit. The control unit is used for controlling the controlled unit to be at a normally working state, and the detection unit is used for detection. If the controlled unit is at the normally working state, the detection unit will remind the mode switching unit of carrying out the corresponding mode switching, thereby changing the property of the control unit, and reducing the overlapping of a control section with an input signal frequency spectrum section of the controlled unit. The controlled unit is a voltage-controlled oscillator, and an input signal of the controlled unit is a baseband signal. The control unit is a phase-locked loop, and the detection unit is a locked detection unit or delay unit. The circuit can be used in various types of radio frequency transceivers, achieves the modulation of carrier frequency, is simple in structure, is low in power consumption, and has no carrier frequency drift.

The invention discloses an all-digital phase-locked loop system and a frequency calibration method of the all-digital phase-locked loop, and the all-digital phase-locked loop system comprises: an all-digital phase-locked loop, which is used for correspondingly generating a first control code and a second control code when a corresponding loop is locked according to a carrier frequency signal and a crystal frequency signal in a calibration stage, and generating a target output frequency signal according to the crystal frequency signal and the second frequency amplification factor in a normal working stage; and a calibration unit, which is used for calibrating the first frequency amplification factor according to the first control code and the second control code to generate a second frequency amplification factor. According to the all-digital phase-locked loop system and the frequency calibration method of the all-digital phase-locked loop, the crystal frequency can be tracked, the frequency signal meeting the system requirement is output, and the risk that the accuracy of the frequency output by the all-digital phase-locked loop is reduced when a carrier wave is interfered or no carrier wave exists is reduced.

The invention discloses a carrier-free steganography method and system based on blockchain private key mapping. The carrier-free steganography method comprises the steps that: a message sender and a message receiver generate the same private key database respectively; the message sender converts the secret message into one or more serial numbers to obtain corresponding private keys, calculates a public key address of each corresponding private key, takes each public key address as a receiving address in a transaction order, and broadcasts the transaction order on the blockchain; and the message receiver generates a plurality of alternative addresses according to the private key database, obtains a corresponding private key in combination with the receiving address, and recovers the secret message. The blockchain information is used as a carrier, so that the message receiving consistency of two communication parties and the robustness to link noise are realized, the risk that carrier statistical information exposes communication facts is eliminated, the information transmission efficiency is improved, and the resource search overhead is greatly reduced.

The invention discloses a carrier-free covert communication method and system based on a depth discriminator, and the method comprises the steps: building a code table, collecting a plurality of images, distributing code words with the length of p to each image according to the code table, and building a carrier library; constructing a mapping model by learning a mapping relationship between each image and a corresponding code word, and sending the mapping model to a receiver; converting the secret message into a binary code, and dividing the binary code into a plurality of bit segments according to a set length P; and querying an image corresponding to each bit segment in a carrier library, and sending the formed secret-carrying image sequence to a receiver, so that the receiver recovers the secret message according to the secret-carrying image sequence and the neural network model. By constructing the code table, the depth model capable of automatic learning is trained to realize image-based covert communication, automatic model construction is realized, and the problem that a large amount of image data is difficult to search is solved.

Carrier management in a wireless communication device assigned a set of two or more carriers by a wireless communication network is disclosed. In one aspect, a method of carrier management includes transmitting data over the wireless communication network on one or more carriers forming a subset of active carriers from the set of carriers assigned to the wireless communication device. A first performance metric is determined indicative of operating conditions across the set of carriers assigned to the wireless communication device. A desired number of carriers on which to transmit data based on the first performance metric is determined. The desired number of carriers on which to transmit data is compared with the number of carriers in the subset of active carriers. The subset of active carriers is dynamically adjusted based on the comparison and subsequent data is transmitted over the wireless communication network using the adjusted subset of active carriers.

The invention discloses an electro-optical switch or an optical attenuator, comprising an MZI (Mach-Zehnder Interferometer) structure, wherein the MZI structure consists of a first waveguide arm and a second waveguide arm; each of the first waveguide arm and the second waveguide arm comprises a waveguide capacitor structure; the first waveguide arm is externally connected with a first electric signal source; the second waveguide arm is externally connected with a second electric signal source; under the actions of the external electric signal sources, a great number of carriers are injected into an intrinsic region of ridge waveguide of the first waveguide arm, while no carriers or a small number of carriers are injected into an intrinsic region of ridge waveguide of the second waveguide arm; the connected electric signal sources simultaneously cause temperature change to the two waveguide arms; and the temperature change caused to the second waveguide arm is the same with or infinitely close to the temperature change caused to the first waveguide arm. The electro-optical switch or the optical attenuator disclosed by the invention can decrease the change difference of a refractive index under a heat effect caused by the temperature difference between the two waveguide arms, and improve the component efficiency.

The invention discloses a half-cycle jumping measuring method and a device for satellite navigation. The half-cycle jumping measuring method comprises the following steps: judging whether the current telegraph-text sign bit is same as the previous frame telegraph-text sign bit, and if so, carrying out half-cycle jumping correction; if not, and judging whether the accumulated value of the final M integrals of the current telegraph-text sign is the same sign, and if so, judging whether the current telegraph-text sign bit and the accumulated value of the final M integrals are the same sign, and if so, judging the the current telegraph-text sign bit has no carrier phase half-cycle jumping, and if not, carrying out half-cycle jumping correction. The half-cycle jumping measuring method and the device for satellite navigation have no need to read the phase information of each pseudo code width and the initial and ending phase information of each data bit, and only need to read the discontinuous coherent integration data and the phase information of each data bit so that the position of the half-cycle jumping is accurately judged and corrected. The half-cycle jumping measuring method and the device for satellite navigation has the advantages of simple method and accurate calculation, and facilitate to the achievement of a hardware receiver.

The invention discloses a method of modulating the amplitude of electromagnetic wave in a free space by use of an adjustable artificial electromagnetic super surface. According to the invention, the amplitude of incident electromagnetic wave is modulated by use of an adjustable artificial electromagnetic super surface to make the amplitude of reflected electromagnetic wave change with a modulation signal applied to the adjustable super surface so as to realize information back-transmission, and the modulation depth can be controlled flexibly. The method can be used in one-way information collection. Information sending equipment adopted is simple, and there is no need for a carrier generation device. The super surface is composed of super material unit structures arranged periodically. The front of the unit structures contains two isosceles trapezoid copper pieces which are symmetrically arranged up and down, and a varactor is welded between the trapezoids. Both ends of the varactor are connected with a modulation signal. The method has the following advantages: carrier signals within a certain frequency scope of an X band can be modulated; the modulation depth is controllable; and an information sender passively receives carrier signals emitted by a base station, no carrier generation device is needed, so that the equipment is simple, and the mobility and distributivity are improved.

Disclosed is a magnetic bearing system capable of simplifying a demodulation operation and reducing a processing load associated with a magnetic levitation control. A carrier signal having a frequency fc is apply to a sensor through a filter. The sensor operates to modulate the carrier signal, and a difference amplifier operates to calculate a difference between the amplitude-modulated signal FAM (t) and a sensor reference signal Fstd (t). An A / D converter operates to A / D convert a difference signal Fsub (t) output from the difference amplifier to a discretized sensor signal. In the A / D conversion, a sampling frequency fs is set to satisfy the following relation: fc: fc=n·fs or fc=fs / 2 (n is a natural number). Thus, the discretized sensor signal includes no carrier wave, and therefore a demodulation operation which has been previously essential can be simplified.

Satellite provisioning of cell service for an in-vehicle telematics control unit (“TCU”) is presented. Thus, a truly carrier independent TCU is facilitated. A TCU may be provided with a cellular modem and two or more SIM cards, each associated with a cellular carrier that has approved the modem and their SIM card. The TCU may also be provided with connectivity to a satellite, such as, for example, via an SDARS antenna and processing module, that can receive and process SDARS audio and data signals. When a user desires to change from one of the cellular carriers to another, provisioning data for the new carrier's SIM, now already in the telematics system, may be (i) sent over the satellite, (ii) received at the satellite antenna, and (iii) passed to a telematics processor. The telematics processor, in turn, may (iv) deliver the provisioning data to the cell modem, which may then (v) program the appropriate SIM with the provisioning data, thus allowing cellular communications on the new carrier's network. The inventive functionality facilitates easily switching carriers as one crosses a border, or when a new vehicle is imported to a given country, and cellular service then or there available on one of the approved carriers is easily chosen by a user and turned on. The TCU may also include a Wi-Fi module, configured to receive provisioning instructions or data over a Wi-Fi network.

Satellite provisioning of cell service for an in-vehicle telematics control unit (“TCU”) is presented. Thus, a truly carrier independent TCU is facilitated. A TCU may be provided with a cellular modem and two or more SIM cards, each associated with a cellular carrier that has approved the modem and their SIM card. The TCU may also be provided with connectivity to a satellite, such as, for example, via an SDARS antenna and processing module, that can receive and process SDARS audio and data signals. When a user desires to change from one of the cellular carriers to another, provisioning data for the new carrier's SIM, now already in the telematics system, may be (i) sent over the satellite, (ii) received at the satellite antenna, and (iii) passed to a telematics processor. The telematics processor, in turn, may (iv) deliver the provisioning data to the cell modem, which may then (v) program the appropriate SIM with the provisioning data, thus allowing cellular communications on the new carrier's network. The inventive functionality facilitates easily switching carriers as one crosses a border, or when a new vehicle is imported to a given country, and cellular service then or there available on one of the approved carriers is easily chosen by a user and turned on. The TCU may also include a Wi-Fi module, configured to receive provisioning instructions or data over a Wi-Fi network.

Radio communication devices receive timing reference pulses from a timing generation device and can acquire synchronism based on the received pulses, so that even on the ultra wide band (UWB) radio communication system, where there is no carrier as exists in the conventional radio communication systems, there is no need to add a redundant preamble signal ahead of transmitted information in order to acquire initial synchronism. In order to receive an asynchronous signal, there is no need to perform detection for a very long time to find whether the signal is present or absent. The application of an access control system according to the present invention to UWB radio communication implements high-speed asynchronous radio communication.

The invention belongs to the technology filed of wireless communication, relating to a method for jointly demodulating MSK (minimum shift keying) and DSSS (direct sequence spread spectrum) and a demodulator thereof. The demodulator comprises an error information obtaining module, a match filter module, a synchronous information trapping module, a demodulating module and a tracking module; and themethod for jointly demodulating MSK and DSSS comprises the following steps of: (1) obtaining error information, (2) matching and filtering the error information, (3) trapping synchronous information,(4) demodulating, (5) tracking, or the like, and sending demodulation results to parent process so as to complete communication process. The invention has the advantage of better frequency compensation ability, thereby, solving the problems that a method for dispreading and demodulating direct sequence spread spectrum signals needs to be frequency offset estimated, complex extraction of PN code synchronization and bit synchronization, etc. Compared with the existing dispreading and demodulating method, the invention is simple as needing no carrier recovery module nor bit timing module, and isapplicable to the wireless communication system.

A channel access protocol method to impart bandwidth fairness while maximizing throughput in a class of contention-based-access (CBA) TDMA networks that has no carrier sense capability, and that experiences biased detection at the receiver (base station) by virtue of physical layer detection algorithms is disclosed.

The invention relates to a text carrier-free steganography method and system based on a component association graph. The method comprises: splitting characters in a text containing information to be hidden into components according to a Chinese character mathematical expression; forming a component association graph for each associated component, wherein the part association graph comprises at least one topological graph; by adopting a breadth-first search algorithm, determining a binary sequence of each topological graph according to the number of association times of all the components; connecting the binary sequences of the topological graphs into a text identification code; splitting the information M to be hidden into m keywords, and converting the m keywords into m binary sequences;establishing a mapping relationship between the binary sequence of each keyword and the text identification code by using a matching algorithm, and determining a position label sequence of the mappingrelationship; encrypting the position label sequence; and sending the encrypted position label sequence and text to a receiving terminal. Detection of various steganalysis is effectively resisted through carrier-free information hiding.