384 results about "Frequency code" patented technology

A frequency hopping pattern associated with a remote short-range wireless communications network is identified. Based on the identified frequency hopping pattern, a frequency hopping pattern for communications in a local short-range wireless communications network is selected. In addition, a timing for the selected frequency hopping pattern is selected based on the identified frequency hopping pattern timing. One or more symbols, such as OFDM symbols, may be transmitted according to the selected frequency hopping pattern and the selected timing.

Methods and apparatus for processing of GNSS data derived from multi-frequency code and carrier observations are presented which make available correction data for use by a rover located within the region, the correction data comprising: the ionospheric delay over the region, the tropospherπc delay over the region, the phase-leveled geometric correction per satellite, and the at least one code bias per satellite. In some embodiments the correction data includes an ionospheric phase bias per satellite. Methods and apparatus for determining a precise position of a rover located within a region are presented in which a GNSS receiver is operated to obtain multi-frequency code and carrier observations and correction data, to create rover corrections from the correction data, and to determine a precise rover position using the rover observations and the rover corrections. The correction data comprises at least one code bias per satellite, a fixed-nature MW bias per satellite and/or values from which a fixed-nature MW bias per satellite is derivable, and an ionospheric delay per satellite for each of multiple regional network stations and/or non-ionospheric corrections. Methods and apparatus for encoding and decoding the correction messages containing correction data are also presented, in which network messages include network elements related to substantially all stations of the network and cluster messages include cluster elements related to subsets of the network.

A system for optical communication send optical signals over a plurality of wavelength channels. Each wavelength channel comprises a number of orthogonal subchannel frequencies which are spaced apart from one another by a predetermined amount. Each of the subchannel frequencies is modulated with data from a data stream. The data modulation scheme splits a subchannel frequency code into H and V components, and further processes the components prior to modulation with data. The various data-modulated subchannels are then combined into a single channel for transmission. The received signals are detected and demodulated with the help of a symbol timing recovery module which establishes the beginning and end of each symbol. A polarization mode distortion compensation module at the receiver is used to mitigate the effects to polarization more distortion in the fiber.

A method, an apparatus and a system for sending Sounding Reference Signal (SRS) and a method, an apparatus and a system for receiving SRS are disclosed in the present invention, which are used to reduce the requirement for Time Frequency Code (TFC) resource during the process of sending the SRS, and meanwhile to ensure the precision of channel information estimation. The method includes the steps of: determining a first frequency band required by sending the SRS, and determining a second frequency band whose width is smaller than the width of the first frequency band; according to the mode that the average interval for sending the SRS on the first frequency band is larger than the average interval for sending the SRS on the second frequency band, respectively sending the SRS on the first frequency band and the second frequency band.

A condition of a short-range wireless communications link is determined. From this determination, one or more frequency hopping patterns are selected for the short-range wireless communications link. The selected pattern(s) may employ different frequencies for adjacent time slots when the determined condition indicates the short-range wireless communications link is susceptible to inter-symbol interference (ISI). Conversely, the selected patterns may employ the same frequencies for two or more adjacent time slots when the determined condition indicates the short-range wireless communications link is not susceptible to ISI.

The invention discloses a partial echo compressed sensing-based quick magnetic resonance imaging (MRI) method. The conventional imaging method has low speed and high hardware cost. The method comprises the following steps of: acquiring echo data of a random variable density part, namely intensively acquiring data in a central area of a k-space and acquiring the data around the k-space randomly and sparsely to generate a two-dimensional random mask, adding the two-dimensional random mask into every data point which needs to be acquired on a frequency coding shaft to form a three-dimensional random mask, and acquiring the data of the k-space according to the generated three-dimensional random mask; re-establishing by projection onto convex sets based on a wavelet domain which is de-noised by soft thresholding; and nonlinearly re-establishing a minimum L1 normal number based on finite difference transformation, namely sparsely transforming an image space signal x, determining an optimization objective and solving the optimization objective. By the method of the invention, partial echo technology and compressed sensing technology are combined and applied to data acquisition of MRI, sothat echo time is shortened, and data acquisition time is shortened at the same time.

The present invention provides an accurate and real-time acquisition and monitoring of three-dimensional location information about a target, in particular a target inside a subject's body during a medical procedure. This is achieved in accordance with the invention by marking the target location by a small-size location marker, which can be detected and located with high signal-to-noise ratio of the detection by a detection system located at a distance from the target. Provided by the invention is a location marker, a target location system utilizing such marker, and also a novel antenna system suitable to be used in the target location system. The marker of the present invention is a passive electronic device, which “responds” to an external high radio frequency electromagnetic field by a periodic time pattern of a single (certain fixed value) relatively low frequency, as compared to the known devices of the kind specified emitting a frequency coded signal.

The present invention relates to a selecting method for the optimal mode of the intra prediction coding used for video frequency coding, which belongs to the video frequency coding and decoding field. The steps of the method are that a rate-distortion cost function is constructed on the basis of a prediction code rate; the rate-distortion cost of each prediction mode is calculated by the structured function, and the prediction mode with minimum rate-distortion cost is selected as the optimal mode of the intra prediction coding according to the calculating result. Proportionally, the present invention also provides a device for the selecting of intra prediction coding optimal mode of the video frequency coding. The present invention effectively avoids actually coding every blocks during the rate-distortion optimizing process on the basis that the selected mode is closer to the optimal mode of the original rate-distortion optimization model selecting, and greatly improves the coding efficiency on the precondition of ensuring little change on the code rate and the PSNR of the coding and the full searching method.

The invention relates to a face recognition based monitoring device and an embedded type door monitoring system, wherein the face recognition based monitoring device mainly comprises a video frequency gathering module, a video frequency coding module, a face recognition module, a control module and a communication module. The face recognition can be operated to a collected video frequency image, and a corresponding control signal is sent according to the recognized result, simultaneously, the video frequency coding also can be operated to the collected video frequency image to store an on site image. The embedded type door monitoring system comprises a photographing device, a monitoring device used for the face recognition and a background server, the corresponding door monitoring system is controlled through the face photographed by the photographing device after the face is recognized, to control the in-out of the personnel, simultaneously, the background server can manage the data and can realize the organic integration of the face recognition and a video frequency monitoring system, thereby realizing that more utility functions are provided for users, and effectively improving the security and the operational convenience of the door monitoring system.

This technology relates to an encoding device, an encoding method, and a program capable of improving audio quality and more efficiently encoding audio. A first high-frequency encoding circuit encodes a high-frequency range based on a low-frequency subband signal and a high-frequency subband signal and obtains a high-frequency code amount. A low-frequency encoding circuit encodes a low-frequency signal with a code amount determined by the high-frequency code amount and a low-frequency decoding circuit decodes the encoded low-frequency signal. A subband dividing circuit divides a decoded low-frequency signal obtained by decoding into decoded low-frequency subband signals of a plurality of subbands and a second high-frequency encoding circuit generates a high-frequency code string such that a code amount of the high-frequency code string for obtaining a high-frequency component is not larger than the high-frequency code amount based on the decoded low-frequency subband signals and the high-frequency subband signals. The present invention is applicable to the encoding device.

Methods, systems and apparatuses are provided for transmitting and receiving space-time block coded data in a wireless communications system with co-operative relays. A source node transmits RF signals representing first and second sets of data symbols in respective first and second channels (in time frequency code or any combination) of a wireless communications system, the first and second sets of data symbols being for transmission from separate antennas respectively according to a space-time block code. A relay node receives the RF signals representing the first set of data symbols in the first channel and transmits RF signals representing the first set of data symbols in the second channel. A destination node received the RF signals representing the second set of data symbols from the source node and the RF signals representing the first set of data symbols from the relay node. This enables decoding of the received RF signals representing the first and second sets of data symbols according to the space-time block code.

A system and method for channelization and data multiplexing in ultra-wideband (UWB) wireless communication system is described. The spectrum allocated for UWB in a multi-bank OFDM (orthogonal frequency division multiplex) system is subdivided into various bands. A set of time frequency codes (TFC's) is defined, wherein each code specifies one of a plurality of unique band versus time sequences for a particular band group, for sequential data symbols of a given piconet. The combination of FDMA and TFC's provides a data complexing system supporting up to 30 simultaneously operating piconets, and a simplified interface between the MAC and PHY.

The invention provides a random access method. After sending a random access pilot frequency code on a physical random access channel resource, UE (user equipment) determines a RA-RNTI (random access-radio network temporary identity) as well as a common sub-band and a wireless frame used by a base station for the authorization of a physical downlink control channel PDCCH according to an index number Preamble_id of a sent random access sequence and the index number of a cluster in which a used synchronization sub-band is located, so as to skip to the wireless frame and the common sub-band to monitor a random access response. After receiving the Preamble code sent by the UE, the base station determines a wireless frame and a common sub-band used in sending the random access response based on the same method as the UE. Therefore, the UE supporting a single sub-band working mode is ensured to be able to normally accomplish the random access process, and the random access method is suitable for a wideband access system in which ''UE supporting single sub-band working mode'' is introduced.

A control method of synchronizing communications between or among a plurality of devices in a communication system includes detecting beacons from the plurality of devices in the communication system, establishing a reservation for at least a portion of the plurality of devices in the communication system, each reservation being a frame interval in which to transmit symbols from one device to one or more other devices in the communications system, determining, by each device, a time-frequency code for each of the other devices in the communication system according to the detected beacons from the other devices, adjusting a frequency band for transmission by a respective device according to the determined time-frequency code, and transmitting a plurality of symbols from the respective device using the adjusted frequency band.

The invention discloses a rock heterogeneous quantitative evaluation method based on magnetic resonance imaging. Three-dimensional space orientation of rock can be realized by layer selection pulse, phase coded pulse and frequency coded pulse. An imaging signal can be obtained by applying a spin-echo sequence, and optimization selection of imaging experimental parameters can be carried out through experimental scale. On the basis, a nuclear magnetic imaging signal obtained by experimental measurement is subjected to digital image processing so as to generate a pseudo color graph. By means of the relationship between the porosity and nuclear magnetic imaging signal intensity of a stand sample, the total porosity and porosity and distribution spectrum of a single layer can be obtained. Multi-layer imaging results are compared and a porosity heterogeneous coefficient is defined, so that the longitudinal porosity distribution characteristic and heterogeneity of rock can be obtained. In addition, by applying a first-order spherical variation function model and a grid search method, characteristic parameters of a variation function can be obtained. Heterogeneous coefficients and relative heterogeneous coefficients can be defined to realize longitudinal and horizontal heterogeneous quantitative characterization of rock.

A backscatter passive wireless control system and method employs frequency coding using frequency components generated from an interrogating field using a passive nonlinear element such as a diode in a passive transponder tag. In particular, InterModulation Distortion (IMD) frequency components may be generated which are shifted in frequency from the interrogating signal to assist in backscatter detection at a receiver but are still in band, e.g., in an ISM band. The shifted frequency components may be swept or stepped over a range and passive elements in the tag encode a tag ID by selecting specific frequencies to be backscattered. A manually operated switch may couple an antenna to the transponder to allow battery free control.

A small district synchronization method of wide band time duplex beehive system includes: (1) the main synchronization channel of descending synchronization channel is set in the time space DwPTS of descending guide frequency, the descending guiding frequency code which is sent at the DwPTS time space of sending the main synchronization channel is the synchronization symbol of OFDM; (2) using thepower window to search and finish the descending time gross synchronization; (3) determine accurate position of the OFDM synchronization symbol, and obtain the number of the OFDM synchronization symbol. The invention also discloses a small searching method which is suitable for the wide band time duplex beehive system and can realize the small district searching quickly and accurately.

The invention discloses a method and device for transmitting and receiving channel sounding reference signals, which are used for reducing required time-frequency code resources for transmitting an SRS (Sounding Reference Signal) and simultaneously assisting a communication system to realize uplink and downlink transmissions with better performances. The method comprises the following steps: a user terminal determines a first pre-coding matrix used for coding a channel sounding reference signal for assisting the uplink transmission and a second pre-coding matrix used for coding the channel sounding reference signal for assisting the downlink transmission; the user terminal uses the first pre-coding matrix and the second pre-coding matrix to respectively code the channel sounding reference signals so as to obtain a first channel sounding reference signal and a second channel sounding reference signal; and the user terminal transmits the first channel sounding reference signal and the second channel sounding reference signal to a base station.

The invention relates to a method for rate control of video coding, which includes: it allocates the surplus or overruns bit to the follow-up GOP in the controlling method for the GOP layer rate. It sets the quantitative parameters in accordance with the image complexity and pre-bit-rate allocation of I frame to make the use of resources more rationally and effectively in frame-rate controlling method. It controls the quantitative parameters of the current P frames to contain the serious downward trend of P Frame encoding quality due to lack of residual rate when GOP P frame coding rapidly decline.

The present invention relates to a chromatic degree equalization method and a chromatic degree quantification parameter correcting method used for the video frequency coding. The equalization method comprises: the method obtains the brightness component residual error SADY and chromatic degree component residual error SADY between the present image and the advancedly measured image; after obtaining the brightness component residual error SADY and chromatic degree component residual error SADY, the residual error SATDY and SATDC in the frequency field is got through calculation; on basis of the residual error SADY, SATDC and brightness quantification parameter QPY and the correcting chromatic degree quantification parameter QPC, the coding is held respectively on basis of the brightness component and the chromatic degree component from the brightness quantification parameter QPY and the chromatic degree quantification parameter QPC. Through the method, using the present image brightness and the chromatic degree component residual error and the comparison of the distribution, adjusting the chromatic degree quantification parameter, and controlling the compress ratio of the chromatic degree component, thereby balancing the peak value SNR for the chromatic degree component and the brightness component, further balancing the renewing quality and saving code rate.

A radio transmitter system responsive to a binary signal drives a narrow bandwidth VLF or LF antenna. A generator derives a first variable frequency wave frequency coded based on bit values of a binary signal. An arbitrary impulse response signal processor responsive to the first wave derives a first output signal having real and imaginary components representing the shape of a modulating wave having a variable amplitude envelope and the frequency of the coded values. A transmitter responsive to the processor output signal and a VLF or LF carrier supplies the antenna with another output signal including a modulation wave having a shape that is a substantial replica of the modulating wave shape. The processor causes the signal emitted by the antenna system to include modulation having a shape that is substantially the shape of the first wave.

The present invention is directed to multi-element antennas that include, for each adjacent pair of antenna elements, at least one switch arranged to selectively connect that pair to thereby selectively alter an antenna dimension. Accordingly, a multi-element antenna can be configured to enhance its gain at different operational frequencies while a corresponding impedance matching network can enhance the impedance match (i.e., reduce reflected signal energy) between the antenna and a corresponding system (e.g., a transceiver system). The antenna and system can thus be effectively tuned across a wide operational band. The antenna and impedance matching network are configured with switch command signals and match command signals that are provided in response to each of a plurality of frequency codes.

The invention discloses a coherent optical time-domain reflectometer based on detection frequency coding, which comprises a laser, a first coupler, a frequency coder, a radio-frequency driver, a circulator, an optical interface, an optical filter, a second coupler, a photoelectric detector, a radio-frequency amplifier, a data acquisition module, a signal processing module and a display module. Laser light emitted by the laser passes through the frequency coder for frequency coding to obtain pulses of detection frequency pulse light and filling light which is complementary to the time sequence of the detection frequency pulse light. The frequency of the pulse of the detection frequency pulse light is different from the frequency of the pulse of the filling light. After the respective backward Raleigh scattering signals of the detection frequency pulse light and the filling light in an optical fiber line are fed back, the detection frequency pulse light and the filling light enter the optical filter through the third port of the circulator, the filtered detection light signal is coherent with local oscillator light at the second coupler, then coherent medium-frequency signals are output by the photoelectric detector and finally the medium-frequency signals are acquired and processed to obtain a time-domain curve which reflects the characteristics of the optical fiber line.

A frequency hopping pattern of a frequency hopping signal is detected by use of spectrogram-generating software in a digital storage oscilloscope. By using a spectrogram, a hopping pattern can be determined without having to demodulate the signal, recover the phase or frequency of the carrier, determine optimal sample timing, or determine system timing. A block of data that contains at least one repetition of the hopping pattern in analyzed with respect to known hopping patterns as well as with respect to the duration in time of the relevant symbols of that data.