43results about How to "Reduce time synchronization requirements" patented technology

The invention discloses a method for transmitting data based on Orthogonal Frequency Division Multiplexing (OFDM), which is applied to transmission of uplink data of middle-distance and short-distance wireless communication systems and is characterized in that: available frequency band of the system is equally divided into N basic sub-frequency bands in advance, wherein the method comprises the following steps: a transmitting site transmits data to a receiving site by a single sub-frequency band or M combined sub-frequency bands, wherein M is equal to 2*n; the transmitting site employs a sampling rate of fs or M*fs of a baseband sample; the receiving site receives data sent from one or a plurality of transmitting sites in the available frequency band; and the receiving site employs a sampling rate of N*fs of the baseband sample. The invention further provides a system for transmitting data based on the OFDM. The method and the system are based on the OFDM technology and combined use of the sub-frequency bands; according to the method and the system, the transmitting site and the receiving site in the wireless communication system are permitted to have different bandwidth configurations, the transmitting site can utilize lower configuration while the receiving site can utilize higher configuration, thereby improving the efficiency, the spectrum efficiency, the throughput rate, etc.; in addition, a plurality of user sites communicating with an access point simultaneously can be realized.

The invention provides a data transmission method based on OFDM for transmitting data from J sending sites to one receiving site at the same time; J is positive integer; the method comprises that: the receiving site divides usable frequency band into N basic sub frequency bands, the J sending sites dispatch respectively exclusive Mj basic sub frequency bands, j is an element of a set [1, J] and is a positive integer, and the formula indicating the relationship between Mj and N is as shown in the specification; the J sending sites respectively carry out IFFT (inverse fast fourier transform) treatment to respectively transmitted OFDM data, the Jth sending site carries out IFFT treatment with length of MjxK point to the data, the sampling rate is Mjxfs; the J sending sites respectively modulate the IFFT treated data, the jth sending site modulates the data to Mj basic sub frequency bands; the J sending sites sends the data on respectively exclusive Mj basic sub frequency bands; the receiving site receives the data sent by the J sending sites within the range of the N basic sub frequency bands at the same time, carries out FFT (fast fourier transform) treatment of NxK point, the sampling rate is Nxfs. The method allows bandwidth non-equivalence communication and allows simultaneous access of a plurality of users.

The embodiment of the invention discloses an authentication method and device and a storage medium. The method comprises the steps that a terminal sends a first authentication request message carryinga token to a server; the server sends the first authentication response message to the terminal; the terminal sends a second authentication request message carrying a sequence ciphertext and a targetdynamic password to the server, the target dynamic password is encrypted from local registration parameters, an original key and sequence data of the terminal, and the sequence ciphertext encrypts the self-sequence data; and the server sends a second authentication response message carrying an authentication result to the terminal, wherein the authentication result is used for indicating that thetarget dynamic password is authenticated according to the sequence ciphertext, the local original key of the server and the registration parameter. The symmetric key function and the HMAC technologycan be used between the server and the terminal for registration and authentication, the calculation speed can be increased, the expenditure of time and space is reduced, the requirement of sequence data for time synchronization is low, and the method is suitable for authentication of transnational and cross-regional terminals and servers.

The invention, which belongs to the indoor positioning technology, disclosed a method for positioning a non-cooperative target by using channel pulse response autocorrelation sequence. The method comprises the following steps: establishing a location database; arranging positioning chips on each management object and storing each management object information parameter in the database; determining the positions of the management objects and displaying the current positions of all the management objects on a visual interface. In the invention, the channel pulse response autocorrelation sequence is used as a signal for establishing the database. After a receiver receives the signal, autocorrelation processing is performed respectively. And the processed signal and preset node position parameters which are relative to each signal receiver are used to establish the positioning database. In the method, more discrete time domain information is used, positioning information is abundant and positioning accuracy can be further raised. Compared to the background technology, the positioning accuracy by using the method of the invention can be raised more than 10%. Sensitivity to position differences in positioning areas and the positioning accuracy can be effectively raised. Requirements, such as time synchronism and the like, can be reduced.

The invention discloses a mobile equipment position estimation method based on multi-base-station channel state information fusion, and belongs to the technical field of radio mobile positioning. The method comprises the following steps: enabling a base station to collect a non-real-time channel state information sample from mobile equipment; extracting angular domain power spectrum channel characteristics; calculating the difference degree between the samples according to the angular domain power spectrum channel characteristics to obtain a single base station sample difference degree matrix; enabling a data fusion node to fuse the plurality of single base station sample difference degree matrixes to obtain a global sample difference degree matrix; enabling the data fusion node to create a channel map for the sample data set according to the global sample difference degree matrix, and calibrate the channel map; and enabling the base station to collect real-time channel state information from the mobile equipment, and performs matching positioning by combining the sample data set and the channel map to obtain real-time position information of the mobile equipment. Accurate time synchronization between the base stations is not needed, field survey is not needed, the manual participation degree is reduced, and automatic operation of the mobile positioning system is achieved.

The invention discloses a cable insulation monitoring method and system based on high-voltage power frequency and low-voltage ultralow frequency, and belongs to the field of cable insulation monitoring. The method comprises the steps: coupling a low-voltage ultralow frequency signal in a high-voltage power frequency cable line; respectively measuring zero-sequence ultralow-frequency active and reactive power average values at the head and tail ends of each line; calculating the average value and the standard deviation of the ultralow-frequency dielectric loss of each line; judging whether theaverage value and the standard deviation of the ultralow-frequency dielectric loss exceed set thresholds or not; calculating correlation coefficients between adjacent lines, and comparing the correlation coefficients with the average correlation coefficient; calculating the change rate of the ultralow-frequency dielectric loss average value of each line, carrying out normalization processing to construct a distribution function, solving the insulation degradation probability, and outputting the insulation degradation probability when the insulation degradation probability is greater than the basic proportion. According to the invention, on the premise of realizing cable insulation online monitoring, various data processing methods are utilized to formulate an evaluation basis for a specific line, and the cable insulation state is evaluated timely and accurately.

The invention discloses a data transmission method based on OFDM, which is used for uplink data transmission in a short-to-middle-distance wireless communication system. The available frequency band of the system is divided into N basic frequency sub-bands in advance. The method includes: the transmitting site occupies M basic frequency sub-bands Frequency band, modulate the data to the M basic sub-bands and send it out; the receiving station receives the data sent from one or more transmitting sites within the N basic sub-bands; M≤N, M and N are both positive integer. The invention also provides an OFDM-based data transmission system. The present invention is based on the combination of OFDM technology and sub-frequency bands, allowing the transmitting site and receiving site in the wireless communication system to have different bandwidth configurations, the transmitting site can use a lower configuration to reduce hardware costs, and the receiving site can use a higher configuration to improve bandwidth. Efficiency: Spectrum utilization, throughput, etc., and enables multiple user sites to communicate with access points at the same time.

The embodiment of the invention discloses an authentication method and device and a storage medium. The method comprises the steps that a terminal sends a first authentication request message carryinga token to a server; the server sends the first authentication response message to the terminal; the terminal sends a second authentication request message carrying the target dynamic password to theserver, wherein the target dynamic password is encrypted from a local registration parameter, an original key and a time window parameter of the terminal; and the server sends a second authenticationresponse message carrying an authentication result to the terminal, the authentication result being used for indicating that the target dynamic password is authenticated according to the registrationparameter, the original key and the time window parameter in the time window indicated by the time window parameter. A symmetric key function and an HMAC technology can be used between the server andthe terminal for registration and authentication, the calculation speed can be increased, the overhead of time and space can be reduced, the range of a time window is wide, the requirement for time synchronization is low, and the method is suitable for authentication of transnational and cross-regional terminals and servers.

The invention discloses an automatic final heating device and method oriented to a stable heating route. A positioning device, a temperature measuring device, a coordinated control system and heatingdevices are included; the positioning device is used for positioning the human body and transmitting the positioning information to the coordinated control system; the temperature measuring device measures the ambient temperature of the human body and transmits temperature information to the coordinated control system; the coordinated control system receives position information of a person and the temperature information, and the coordinated control system controls the one or several heating devices needing to work to move to the specific positions according to the position information of theperson; and the temperature measuring device measures the ambient temperature of the person in real time and sends the temperature information to the coordinated control system, and the coordinated control system adjusts the working power of the heating devices according to the current temperature. The automatic final heating device and method can locate the person in an area and measure the ambient environment of the person, the heating devices are moved to the position ear the person and directly heat areas around the person, and the functions of automatic tracking and heating are achieved.

As shown in FIG. 7, a data receiver receives video data and audio data together with a frequency division parameter N that depends on the pixel clock of the video data and the sampling frequency of the audio data, and a count value CTS that is obtained by counting the period of the audio clock that has been subjected to frequency division by the frequency division parameter N, with the pixel clock, which are transmitted from a data transmitter, and subjects the pixel clock to frequency division by the count value CTS, phase-control the divided clock (s501) in accordance with a phase comparison clock (s505) that is obtained by dividing an audio clock (s403) oscillated from a VCO (504) by the frequency division parameter N, thereby generating an audio clock (s403).

Accordingly, the data transmitter and the data receiver can satisfactorily implement multiplexing of audio data and video data, and transmission of the multiplexed data using an existing DVI cable, with a simple structure.

The invention relates to an urban monocular mapping method and system based on GPS constraint and dynamic correction, and the method comprises the steps: screening a curved road section according to the trajectory curvature of a vehicle during driving, and detecting the internal and external parameters of a monocular camera according to the sequence image of the screened curved road section in the monocular camera; determining pose absolute coordinate transformation of the monocular camera according to whether the change of the internal reference or the external reference of the monocular camera is greater than a threshold value or not; and outputting a map according to the pose absolute coordinate transformation and the multi-view intersection measurement of the monocular camera. According to the invention, the monocular camera and the consumer-level GPS equipment are fused for single-vehicle mapping, so that the dependence on a laboratory calibration environment is reduced, and the mapping reliability is improved.

The invention discloses a temperature control system and method using competitive learning. The temperature control system comprises a positioning device, a temperature measuring device, a coordination control system and heating devices. The positioning device is used for positioning the human body and sending positioning information to the coordination control system. The temperature measuring device is used for measuring the environment temperature around the human body and transmitting temperature information to the coordination control system. The coordination control system is used for receiving the position information of the human and the temperature information and controlling the one or more heating devices needing to work to move to appointed positions according to the position information of the human. The temperature measuring device is used for measuring the environment temperature around the human in real time and sending the temperature information to the coordination control system, and the coordination control system is used for adjusting the working power of the heating devices according to the current temperature. According to the temperature control system and method using competitive learning, the human in an area can be positioned, the environment temperature around the human is measured, the heating devices are moved to be nearby the human so as to directly heat the area around the human, and an automatic tracking and heating function is achieved.

The invention discloses an automatic tracking and heating system and method adopting a precise positioning device. The automatic tracking and heating system comprises the positioning device, a temperature measuring device, a coordination control system and heating devices. The positioning device is used for positioning the human body and sending positioning information to the coordination controlsystem. The temperature measuring device is used for measuring the environment temperature around the human body and transmitting temperature information to the coordination control system. The coordination control system is used for receiving the position information of the human and the temperature information and controlling the one or more heating devices needing to work to move to appointed positions according to the position information of the human. The temperature measuring device is used for measuring the environment temperature around the human in real time and sending the temperature information to the coordination control system, and the coordination control system is used for adjusting the working power of the heating devices according to the current temperature. According tothe automatic tracking and heating system and method adopting the precise positioning device, the human in an area can be positioned, the environment temperature around the human is measured, the heating devices are moved to be nearby the human so as to directly heat the area around the human, and an automatic tracking and heating function is achieved.