102results about How to "Reduce bit errors" patented technology

The invention discloses a data transmission method for supporting sub-channel modulation coding, which is used in a wireless local area network. The method comprises the following steps of: acquiring sub-channel modulation coding information which contains spatial stream information, sub-channel modulation mode of each spatial stream and coding rate through a first site; packing the sub-channel modulation coding information by adopting a physical layer data unit frame of a predetermined format; and sending a physical layer data unit of a predetermined format to a second site through the first site to demodulate the physical layer data unit frame so as to obtain received data. The invention also provides a corresponding wireless local area network system. As the modulation mode is selected according to the information condition of each sub-channel, the invention improves the data transmission efficiency, supports adaptive modulation coding on the sub-channel consisting of sub-carrier packets, effectively overcomes the frequency selectivity in the system, improves the performance of the system, and is backward compatible with the existing system.

An optical receiver configuration and method of controlling an optical signal receiver adjusts a decision threshold to reduce the bit error rate (BER). The receiver includes a comparator having a data input and a digital data output. An error detection & correction circuit provides an error signal representative of the number of corrected “1”s and “0”s in the data output from the comparator. Based on the error signal, a control circuit modifies the comparator decision threshold in a direction to reduce the BER of the receiver. Dynamic modification of the decision threshold may also be accomplished. A total percentage error indicator is preferably used as the basis of changing the decision threshold value. The total percentage error indicator may be used to variably adjust the decision threshold by an amount that varies according to the magnitude of the total percentage error indicator to thereby more quickly arrive at an acceptable decision threshold and prevent overshoot. A searching method may also be used to determine the usable range of the comparator before tuning the decision threshold.

An integrated circuit. The integrated circuit is usable in a transceiver module. The integrated circuit includes an input port that is configured to receive a data stream. A clock port on the integrated circuit is configured to receive a reference clock diplexed with another signal or voltage used by the integrated circuit. An eye opening circuit is connected to the input port and clock. The eye opening circuit is configured to retime the data stream received at the input port. An output port is connected to the eye opening circuits The output port is configured to transmit a retimed signal from the eye opening circuit to a device external to the integrated circuit. A bypass circuit is connected to the input port and the output port. The bypass circuit may selectively bypass the eye opening circuit.

A receiver with baseline wander compensation is applicable to a digital communication system. The receiver includes an Analog-to-Digital Converter (ADC), a slicer, a threshold value detector, a gain controller, a baseline wander compensator, a delay circuit, an analog gain stage, and a digital gain stage. The baseline wander compensator is used to perform an operation and a filtering process on a voltage obtained prior to processing by the slicer and a voltage after the processing so as to obtain a baseline wander voltage value for compensation and control. The threshold value detector and the gain controller dynamically produce control signals of analog gain and digital gain. The analog gain stage compensates degrading of communication signals passing through transmission channels in an analog gain manner. The delay circuit is used to compensate the delay of the conversion performed by the ADC. The digital gain stage compensates insufficiency of the analog gain.

The invention is concerned with compressing video transmitting error-code eliminative method based on H.264, in order to eliminate the error-code simply and effectively, it is: combines the error-code cover and the error-code pervasion-control to achieve the error-code elimination by the feedback mechanism of the error-code information; loads the information check error-code occur of the Slice and the statistic of the error-code information such as the losing data location by the serial number of the NALU; establishes the inner error-code information feedback channel of the H.264 system by defining the extending SEI information; achieves the error-code pervasion-control by the sectional time-by-time in-frame coding.

The invention discloses a DMR physical layer four-level modem, belonging to the field of wireless communication technology. The modulator frames original binary data in accordance with a format required by a system and maps the data into quaternary symbols two by two in sequence; zero values are interpolated between the quaternary symbols and root-raised cosine filter is performed on the interpolated data in order to generate band-limited quaternary baseband signals. The demodulator implements a de-DC component treatment on sample data frames of the quaternary baseband signals and carries out matched filtering via a root-raised cosine filter; the filtered data and locally-stored synchronous code waveform are subjected to related operations to find out an optimal extraction / judgment location; afterwards, sampling points of the optimal extraction / judgment location are utilized to calculate dynamic thresholds in a segmenting manner, multilevel judgment is implemented to obtain the quaternary symbols; in the end, the quaternary symbols are reversely mapped to restore binary data information. The invention can implement the framing flexibly in accordance with the requirement of the system and is suitable for a variety of data frames, including a digital communication system of a DMR frame structure.

The invention discloses a self-adaptive optical fiber array type laser transmit-receive system used for spatial coherent light communication, which comprises a self-adaptive optical fiber coupler array, an integrated device, a subunit optical fiber branching device group, a coupling energy photoelectric detector group, a multichannel high voltage amplifier, a multichannel tilt aberration controller, a N X 1 self-adaptive beam combination module, a three-port optical fiber circulator, a signal loading phase modulator, a signal emission laser, a local oscillator laser, a local oscillator optical phase modulator, a mixer, a balanced detector, a digital signal demodulation module, a low pass filter and a frequency mixing piston aberration controller. The self-adaptive optical fiber coupler array is utilized to divide beams and to correct the tilt aberration in a subaperture; the piston aberration between optical fiber arrays is compensated by adopting an optimized control algorithm, so as to realize beam combination to strengthen the light energy of a received signal, and improve the mixing efficiency of signal light and intrinsic light, thereby reducing the bit error rate; the self-adaptive optical fiber array type laser transmit-receive system also can be used as a transmitting terminal, and wavefront pre-compensation for transmitting signal light is realized by utilizing the reciprocity principle of a light path.

The invention provides a time delay compensation device and a time delay compensation method for the self-adaptive optical fiber length in a quantum key distribution system. The device comprises a sending terminal, a receiving terminal and a single optical fiber positioned between the sending terminal and the receiving terminal, wherein the sending terminal comprises a processor, a timer, a classic light laser, a synchronous light laser, a quantum light laser, an electrically-controlled attenuator, a wavelength division multiplexer and a classical light detector; the method comprises the steps of carrying out distance measurement on optical fiber channels, calculating time delay and compensating. According to the device and the method, in the quantum key distribution system, the relative time delay of synchronous light and quantum light is measured and calculated according to the different lengths of the optical fiber channels, and time delay compensation is then added into the sending terminal; the problem of time delay drift caused by the different transmission speeds of light sources with different wavelengths in the same optical fiber is solved by using an active compensation method, so that error codes are reduced, and the stability of system operation is even guaranteed.

A distributed antenna structure applied to a high-speed railway is characterized in that more than one base station is arranged along the high-speed railway, a plurality of distributed antennas are erected equidistantly and symmetrically along the high-speed railway by centering on one base station, the radius of the effective coverage range of each distributed antenna is larger than or equal to the gap between each two adjacent distributed antennas, the distributed antennas are connected with the base stations through optical fibers, each base station comprises a baseband processing unit band, each distributed antenna has a remote radio-frequency unit, and antennas of high-speed trains are communicated with the distributed antennas. The distributed antenna structure applied to the high-speed railway achieves space diversity gain, improves communication reliability, increases communication rate, is remarkably effective in improvement on communication performance and experience and has a wonderful application prospect in future.

The invention relates to a fiber data transmission method based on an asynchronous communication mode. According to the method, an employed high speed data transmission circuit is realized by employing an internal function design mode of an FPGA chip, the realized logic functions comprise data generation, digital clock management, clock compensation, data detection, asynchronous FIFO caching based on Gray code counting and Aurora protocol logic control, and the functions of data generation, digital clock management, clock compensation, data detection and Aurora protocol logic control are realized by employing an FPGA standard setting mode. The method is characterized by realizing asynchronous FIFO caching based on Gray code counting, clock network generation and a transmission circuit function. The method employs a fiber data transmission method combining the asynchronous FIFO caching based on the Gray code counting mode with an Aurora protocol, and thereby data transmission accuracy is improved.

An optical receiver configuration and method of controlling an optical signal receiver adjusts a decision threshold to reduce the bit error rate (BER). The receiver includes a comparator having a data input and a digital data output. An error detection & correction circuit provides an error signal representative of the number of corrected “1”s and “0”s in the data output from the comparator. Based on the error signal, a control circuit modifies the comparator decision threshold in a direction to reduce the BER of the receiver. Dynamic modification of the decision threshold may also be accomplished. A relative percentage error indicator is preferably used as the basis of changing the decision threshold value. The relative percentage error indicator may be used to determine how much to adjust the decision threshold at each iteration of the method to more quickly arrive at an acceptable decision threshold and prevent overshoot. A searching method may also be used to determine the usable range of the comparator before tuning the decision threshold.

The invention provides a receiving method and a receiving device. In a selective diversity, the antenna switch is eliminated when the grouped data is received and the optimal antenna is chosen to decrease the grouping error. The device is provided with a RSSI value detector (41) for detecting a RSSI value of a received signal, a differential value calculator (42) for calculating a differential value of the detected RSSI value and a switch (50) for outputting and choosing the switch signal of a first and second antennas (11), (12). The antenna can be chosen through the RSSI value R1 (t1) and the RSSI value R2 (t1) of a received wave and the differential values delta R1 and delta R1 showing the influence caused by delay, so the antennas having heavy delay caused by human shielding can be detected and the antennas which have small influence on the human shielding can be chosen so as to decrease the grouping error.

The invention discloses a three-segment time-to-digital conversion circuit based on a phase-locked loop. Accurate counting clocks of a plurality of different frequencies and a plurality of uniform split phases are provided for a time-to-digital converter (TDC) through the phase-locked loop, so that accurate measurement of measured time by the TDC is ensured; the phase-locked loop is a three-order type-2 phase-locked loop, and comprises a phase frequency detector, a charge pump, a loop filter, a voltage-controlled oscillator, a frequency divider and an auxiliary state detection circuit; the TDC is a three-segment TDC including a high segment, a middle segment and a low segment; and the high segment of the TDC is provided with a 7-bit linear shift register. According to the three-segment time-to-digital conversion circuit, the phase-locked loop has the advantage of providing stable clocks of different frequencies and uniform phases, so that rough counting and fine quantitation and further fine quantitation of a measured time amount are finished; wide-range measurement is finished; and the measuring accuracy is ensured at the same time. Meanwhile, initial-phase time is measured at a same resolution, so that initial-phase time errors are eliminated, and the resolution and the measuring accuracy are kept constant at the same time.

The invention relates to a display panel and a compensation data transmission method, and the method comprises the steps: generating feature compensation data; transmitting the feature compensation data to a first storage unit; transmitting the feature compensation data stored in the first storage unit to a second storage unit. According to the embodiment of the invention, the compensation data transmission method does not need a Flash memory. A screen module group does not need to be provided with the Flash memory, thereby reducing the physical space occupied by the Flash memory in the screenmodule group. In the embodiment of the invention, the method can generate the feature compensation data through the Mura compensation data, and the feature compensation data is directly stored in a data drive circuit. The method reduces the error codes in the transmission process of the feature compensation data. The method does not need an additional Flash memory on the screen module group, thereby reducing the data transmission link, improving the data transmission efficiency, and reducing the design cost of the display panel.

The invention discloses an inter-frame lossless coding and intelligent decoding method with an error code resistance mechanism. The method includes the step of space-borne coding, wherein sequential images f are obtained; the images fk (k=1, 2 ...) are divided into non-overlapping sub-blocks; (3j+1)th frame images serve as reference frame images, j=0, 1 ..., and partitioning JPEG-LS coding is conducted; inter-frame lossless coding is conducted on (3j+2)th frame images and (3j+3)th frame images by referring to the (3j+1)th frame images; a group of EDC information is inserted behind every K sub-blocks to form an error detection code steam; RS (m, n) error correction coding is conducted; the compressed frame header and the frame tail of each frame are added into each compressed code steam; the step of ground decoding, wherein the code streams are searched for the compressed frame headers according to the distance minimization norm, and the compressed code steam of one frame is extracted; multiple pieces of compressed parameter information are extracted from the frame headers; RS (m, n) decoding is conducted; EDC identification codes are searched for; JPEG-LS decoding is carried out on each sub-block of the (3j+1)th frames independently, inter-frame decoding is conducted on the (3j+2)th frame images and the (3j+3)th frame images by referring to the (3j+1)th frame images, and the whole image is spliced. According to the method, the compression effect on the sequential images is good, and error codes can be well corrected through an RS method.

The invention provides an LED display screen control system (30). The LED display screen control system comprises a front-end controller (31), an LED lamp panel module (35), and a scanning card (33) connected between the front-end controller (31) and the LED lamp panel module (35), wherein the scanning card (33) comprises a first chip (333), and the LED lamp panel module (35) comprises a second chip (351); the first chip (333) is used for receiving and unpacking a data packet coming from the front-end controller (31), processing the image data obtained by unpacking the data packet, and repacking the processed image data, so that the processed image data packet is obtained, output and transmitted to the second chip (351) of the LED lamp panel module (35) in the differential signal manner; the second chip (351) is used for receiving and unpacking the processed image data packet coming from the first chip (333), and generating a control signal and a display data set according to the image data obtained by unpacking the processed image data packet, wherein the control signal and the display data set are transmitted to an LED drive circuit (355) on the LED lamp panel module (35) for carrying out display drive. Therefore, with the LED display screen control system, the problem that the signal transmission stability between the LED lamp panel module and the scanning card is poor is solved.

A receiver with baseline wander compensation is applicable to a digital communication system. The receiver includes an Analog-to-Digital Converter (ADC), a slicer, a threshold value detector, a gain controller, a baseline wander compensator, a delay circuit, an analog gain stage, and a digital gain stage. The baseline wander compensator is used to perform an operation and a filtering process on a voltage obtained prior to processing by the slicer and a voltage after the processing so as to obtain a baseline wander voltage value for compensation and control. The threshold value detector and the gain controller dynamically produce control signals of analog gain and digital gain. The analog gain stage compensates degrading of communication signals passing through transmission channels in an analog gain manner. The delay circuit is used to compensate the delay of the conversion performed by the ADC. The digital gain stage compensates insufficiency of the analog gain.

The invention discloses a follow-up tracking WIFI transmission device and a control method thereof. The device includes a cloud deck controller, and an acceleration sensor, a geomagnetic sensor, a Beidou navigation receiver, a wireless communication unit, a WIFI unit and an antenna cloud deck connected to the cloud deck controller. The device also includes a directional antenna arranged on the antenna cloud deck. The directional antenna is connected to the WIFI unit. The control method includes determining the coordinates of the device itself through Beidou satellite signals and sending the coordinate information to other access points; determining an optimal communication chain according to the combination of a routing algorithm and the coordinate information of the whole communication access point combined; determining the posture information of the device itself through the geomagnetic sensor; calculating the antenna azimuth angle and controlling the antenna cloud deck for antenna alignment. According to the invention, long range WIFI communication is realized and a problem of dynamic moving network construction of multiple access points when using the directional antenna is solved. Effects in aspects of prolonging WIFI communication distance, improving communication security, improving network invulnerability, reducing electromagnetic interference and the like are obvious.

The invention discloses a time phase quantum key distribution system transmitting end. The transmitting end comprises a first semiconductor laser, a circulator, an optical beam splitter, an optical delay line, a phase modulation device, a second semiconductor laser, a third semiconductor laser, an intensity modulator, an optical attenuator and a current driving unit. The first semiconductor laseris connected with the circulator through an optical fiber, the circulator is connected with the optical beam splitter through an optical fiber, the optical beam splitter is connected with the second semiconductor laser through the first optical fiber arm, the first optical fiber arm is provided with an optical delay line, and the optical beam splitter is connected with the third semiconductor laser through the second optical fiber arm. The circulator is connected with the intensity modulator through an optical fiber, and the intensity modulator is connected with the optical attenuator throughan optical fiber; the phase modulation device is arranged on the first optical fiber arm or the second optical fiber arm; the first semiconductor laser, the second semiconductor laser and the third semiconductor laser are all connected with a current driving unit. The quality of the generated optical pulse is better, and the system error code can be reduced.

The invention discloses a method and a system for reducing service error code, which comprises a detection control module adapted to collect and process the pointer adjustment times and calculate the frequency offset value between synchronous digital hierarchy equipment, then compare the calculated frequency offset value with several fixed frequency offset threshold values to obtain the current frequency offset range, and output the frequency offset range to a tributary signal dither elimination module; a tributary signal dither elimination module adapted to de-twit the low-speed tributary signal according to the frequency offset range transmitted from the detection control module, to allow the normal control signal to pass within the permitted low frequency range and provide higher attenuation to the dither signal with higher frequency, thereby ensuring the qualified dither parameter of the output tributary signal. The invention can adjust in time the dither elimination circuit of the lower tributary path in SDH equipment based on the frequency offset situation of the network, so as to efficiently reduce the error code due to over-standard frequency offset in the signal processing circuit.

A magnetostatic communication system comprises a transmitting device and a receiving device, wherein the transmitting device comprises a first microprocessor, a coil and a driving circuit, a microcontroller is connected with the driving circuit for controlling the driving circuit, the driving circuit is connected with the coil for driving the coil to generate a static magnetic field, and the driving coil is arranged in a shielding cylinder; and the receiving device comprises a magnetic induction device and a second microprocessor, the magnetic induction device is connected with the second microprocessor, and the magnetic induction device is a geomagnetic sensor or a magnetosensitive chip. The technical problem which is to be solved in the invention is to provide a magnetostatic communication system and a method thereof, and thus, wireless communication can be carried out quickly, conveniently and safely.

The invention discloses a multiplexing device and a multiplexing method. The multiplexing device comprises an adaptive input identification module, a service building module, a service management module and a multiframe building module, wherein the adaptive input identification module is used for adaptively identifying and caching the types of input code streams; the service building module is used for extracting multiplexing subframes in input multiframes from the cached input code streams according to the types of the input code streams, or building input audio-video data information into the multiplexing subframes; the service management module is used for performing service management distribution on the multiplexing subframes according to service management configuration information, distributing the multiplexing subframes to corresponding multiframes and storing the multiplexing subframes into a specified cache; and the multiframe building module is used for acquiring the multiplexing subframes from the specified cache, building the multiframes according to multiplexing configuration information, and converting the generated multiframes into multiplexing code streams to perform outputting. The multiplexing device and the multiplexing method can realize that different types of the input code streams use the same device to perform multiplexing treatment, save the station building and maintenance costs, improve the easy-to-use performance of front-end equipment, and reduce error codes and fault risks caused by the combined use of a plurality of multiplexers.

Disclosed is a light bursting receiver, which comprises: photodiode, trans-impedance preamplifier, top and bottom detecting circuits, resistance-type potential divider and limiting amplifier. The invention is characterized in that it also comprises feed-forward reset impulse signal generation circuit, delay unit and gate circuit. Charging capacitor in the top detecting circuit can be variable capacitance; the feed-forward reset impulse signal generation circuit comprises limiting amplifier, an envelope pulse-generating circuit, and a reset pulse shaping circuit. The invention has the advantages of improving usage of signal channel, reducing error codes and of eliminating interference.

The invention discloses a multi-channel fusion and mixed data transmission system and method of a high-speed video circuit. The system comprises a high-speed serial data receiving module, a mixed datasynthesis module and a channel data fusion module; wherein the high-speed serial data receiving module receives multiple paths of serial digital signals sent by a focal plane circuit and performs serial-parallel conversion to obtain multiple paths of parallel digital signals; the mixed data synthesis module receives the multiple paths of parallel digital signals, intercepts effective pixel digitalizing bits of the multiple paths of parallel digital signals, and performs re-encoding to obtain multiple paths of mixed digital signals; and the channel data fusion module receives the multiple paths of mixed digital signals, adds auxiliary data according to a data transmission format, performs sorting and channel fusion to obtain a path of digital signals. By adoption of the multi-channel fusion and mixed data transmission system and method, the error codes in the digital transmission are reduced, the image SNR and the data transmission efficiency are improved, the scale of the circuit is reduced, and the resource utilization ratio is improved.

Embodiments of the invention generally provide an electronic device comprising an electrical interconnect component that includes an electrical trace. The electrical trace has geometric characteristics that serve to suppress the skin effect over a large band of frequency components. More specifically, the electrical trace has a thickness that is less than a skin depth for a particular chosen frequency component. By making the electrical trace have a thickness that is less than the skin depth, the current flows through substantially the entire cross-sectional area of the electrical trace for all frequencies up to the chosen frequency component, which reduces the effects associated with the skin effect.

The invention discloses the apparatus and process for data interweaving, wherein the apparatus comprises a group frame unit, an FEC encoding unit, an interweaving unit, a modulation transmission unit, a demodulation synchronization unit, a de-interweaving unit and a de-framing unit. The said method comprises interweaving the transmitted data, de-interweaving, interweaving in each of the data block, and adding the frame header output. The invention can reduce code error and improve the quality for data transmission.

This invention discloses a portable receiver when a train approaches to an early warning announce system including: an antenna for receiving RF signals carrying the train data, an emitting RF signals with warning codes, a super-heterodyne receive circuit connected with the antenna for demodulating the received RF signals to digital codes, a decoder connected with the said super-heterodyne circuit for decoding the digital codes to restore them into the train data signals before emitting, a microprocessor connected with the decoder for controlling the received digital signals and displaying them after check and sending out the warning signals and receiving operators instructions to control the sent warning codes, a transmitting unit connecting the microprocessor and the antenna for receiving instructions of the microprocessor and modulating the warning codes to send them out via the antenna.

An integrated optical transmitting-receiving assembly provided by the present invention comprises an optical chip, an optical transmitting device, an optical coupling device, an optical receiving device and an optical waveguide layer, wherein an isolating groove is arranged on the surface of the optical chip and extends from one side of the optical chip to the other side, and the optical chip is divided into a receiver area and an emitter area which are independent mutually and spatially; the optical transmitting device and the optical coupling device grow epitaxially on the surface of the emitter area, and the optical receiving device grows epitaxially on the surface of an optical reception area; the optical transmitting device, the optical receiving device and the optical coupling device are located in the same layer of the surface of the optical chip, and the optical coupling device is connected with the optical transmitting device and the optical receiving device mutually and separately via the optical waveguide layer.

The invention discloses a decimal carrier synchronization algorithm based on cyclic prefix. The decimal carrier synchronization algorithm solves the problem in the prior art that the carrier synchronization technical precision is not high enough to meet modulation order development requirements. The decimal carrier synchronization algorithm based on the cyclic prefix includes the following steps: dividing received signals into a carrier frequency offset portion and a remaining portion, dividing the carrier frequency offset portion into decimal frequency offset and integral multiple frequency offset, calculating to obtain a single estimation value of the decimal frequency offset, and obtaining the ith estimation value according to the single estimation value of the decimal frequency offset; repeating the step (b), calculating variance of the obtained decimal frequency offset, and calculating a variance average value; arranging a threshold V, if Vf>V, executing the step (a), if Vf<V, locking a current decimal frequency offset estimation value, and conducting frequency offset compensation according to the estimation value. By means of the scheme, purposes of reducing decimal frequency estimation residual, improving system stability, and enabling a system to work in a smaller residual environment are achieved, and the algorithm has high practical value and popularization value.

The invention belongs to the field of secret communication of a communication technology and discloses a method for implementing end-to-end cross-base-station transmission of an encryption voice of an analog cluster system. The method comprises the following steps that: a sending terminal encrypts acoustic code data and then transmits the encrypted acoustic code data to a near-end base station; the near-end base station decrypts the acoustic code data and then extracts the effective acoustic code data; the near-end base station encrypts the acoustic code data and codes the acoustic code data by selecting a channel coding mode which is matched with the characteristic of a wired channel; and a wired modem modulates the data which is subjected to channel coding, and the near-end base station transmits the data to a far-end base station. By adoption of the method, the defect of the conventional communication mode is overcome, accumulation of error codes generated in an uplink / downlink wireless channel and the wired channel can be effectively avoided, the error codes caused by transmission can be reduced as greatly as possible, influence on the safety of the system caused by out-of-control encryption terminals can be reduced within a range of base stations, and the situation that keys of all encryption terminals in a full cluster network are required to be replaced is avoided.