87 results about "Channel polarization" patented technology

The invention discloses a channel-polarization-based encoder for a staggered structure duplication code, and an encoding method and decoding methods thereof. The encoder consists of a duplication bit buffer with a storage capacity of L bits, a bit position mapper with a length N and a channel polarization device with the length N which are connected in sequence. The encoding method based on the encoder comprises the following steps of: embedding duplicated encoding into a channel polarization process, and introducing a duplicated relationship between parts of the bits of code blocks transmitted in sequence during the channel polarization for encoding. In addition, the invention further provides two decoding methods, which comprise the following steps of: decoding by using a simple and rapid successive cancellation (SC) algorithm, and performing iterative decoding by using a Tanner-graph-based belief propagation algorithm with excellent performance. On the basis of the innovative structure encoder, the encoding and decoding methods provided by the invention are stronger in error correction capability under the condition of not increasing the decoding complexity, and the transmission performance is obviously improved. The encoding and decoding methods are particularly applicable to an actual communication engineering system and have a good popularization and application prospect.

The invention discloses a coder based on repeated coding and channel polarization and a coding/decoding method thereof. The coder comprises two coding modules with the same structure; each coding module is provided with a repeated coder group, a bit position mapper with the length of N and a channel polarization device with the length of N, wherein the repeated coder group has m*L output ports and is composed of L sequentially-arranged repeated coders with the repeating times of m; and the two coding modules are connected together through a coding mode selector between the repeated coder and the bit position mapper. The invention provides a concrete method of embedding repeated codes in the channel polarization process to perform channel coding and decoding based on the coder; and compared with the polarization code of the limited length in the prior art, the coding/decoding method disclosed by the invention has stronger error correction capability and obviously improves the transmission performance on the premise of rarely increasing the decoding complexity, is particularly suitable for the practical engineering systems of mobile communication, satellite communication, underwatercommunication and the like, and has good popularization and application prospects.

Embodiments of the invention provide a method and device for determining channel reliability in polarization coding modulation. The method comprises: dividing a channel into m binary input channels, carrying out channel polarization transformation, and using a Gaussian approximation algorithm to calculate a log likelihood ratio Gaussian distribution mean corresponding to the polarization sub-channels according to the equivalent noise variance of the binary input channels obtained by splitting, so as to determine the reliability of the polarization sub-channels. Since the method provided by the invention adopts the Gaussian approximation algorithm, the problem of calculation complexity caused by calculating the channel reliability by using a density evolution tool is avoided. Compared with the scheme of calculating the channel reliability by using the density evolution tool, the calculation complexity of the method provided by the invention is obviously reduced.

The invention discloses a polarization code optimization design method in a four-color visible light communication system. The target of optimization design is to maximize the advantages of channel polarization in the specified four-color visible light communication system. The essence is that the four-color visible light communication system is deemed as four paths of channels, quantitative reliability racking is performed on the polarized channels again according to the influence of the difference of signal to noise ratios of the four paths of channels to the channel polarization, and the channel having the highest reliability is selected as an information bit, so that the performance of the polarization code in the four-color visible light communication system is optimized.

The invention discloses a satellite communication transceiving assembly and a two-dimensional active phased-array antenna. The phased-array antenna comprises a dual-polarized antenna array, a transceiving assembly with a double-radio frequency channel polarization adjusting function, a transceiving feed network, a control and power supply layer, a support framework, a heat dissipation device and a structure accessory. According to the invention, independent polarization adjusting technology of dual-polarization antenna unit in the transceiving assembly is carried out; received N paths of horizontal polarization signals and received N paths of vertical polarization signals are adjusted into N paths of signals through polarization adjustment, and are changed into one path of signal after being subjected to signal synthesis; control of amplitude and phase of polarization adjustment signals is facilitated; and a disadvantage of inappropriate control on the amplitude and phase of signal after the signal is synthesized is overcome. In the phased-array antenna, multiple modules are connected with each other without cables, so space size is effectively used; and a system adopts a phased-array technology to carry out space wave beam scanning, so rapid communication with a satellite system is achieved.

The embodiment of the invention provides an information transmission method and device, an electronic device and a storage medium. The information transmission method comprises the steps of determining at least a polarization code transmission channel of a GFDM (Generalized Frequency Division Multiplexing) system based on a two-step channel polarization transformation method; determining reliability of each polarization transmission channel; obtaining a to-be-transmitted information vector, coding the information vector through a coding method and modulating the coded information vector through a preset signal modulation method to obtain the sent information vector; selecting a target polarization code transmission channel which has the byte number as same as that of the sent information vector and has high reliability from the at least one polarization code transmission channel; and transmitting the sent information vector to a receiving end through the target polarization code transmission channel. According to the embodiment of the invention, the information transmission method which combines the polarization code and the GFDM system can improve the information transmission performance of the GFDM system.

The invention discloses an atmospheric polarization mode detection and course calculation system and method. The system comprises two parts including a four-channel polarization image acquisition apparatus and a data processing computer, wherein the four-channel polarization image acquisition apparatus comprises a four-channel image acquisition module, an image monitoring module, a device driver and a data storage module; the four-channel image acquisition module is connected with the device driver and the data storage module through routes; and the device driver and the data storage module are connected with the image monitoring module and the data processing computer. The method comprises the steps that the data processing computer sends an instruction to the device driver and the data storage module to finish acquisition and storage work of an atmospheric polarization image; a polarization information detection module extracts a polarization degree and a polarization angle of each point from the shot atmospheric polarization image; and a course angle calculation module calculates a course angle of a carrier through the extracted polarization information. The system is simple in structure and low in cost, and processing process and result of image data are conveniently viewed.

The invention provides a continuous encryption physical layer secure transmission method based on polarization code construction, and belongs to the technical field of security. According to the method provided by the invention, a polarization code construction method is improved by properties of eavesdropping channel model features and channel features that can be used by a polarization code, that is, security information bit data are placed in a polarization subchannel set with a good legal receiver and a poor eavesdropper; information encryption is performed on an unsecure area by using the information transmitted by the subchannel that can realize secure information transmission relative to a main channel after channel polarization, thereby ensuring the secure information transmission of the unsecure area. Compared with the existing secure polarization code transmission method, the spectrum efficiency is improved, and meanwhile the transmission rate is improved.

Transmit/Receive (T/R) module that provides multiple simultaneous ground to satellite links with rapid pointing and acquisition. The (T/R) module incorporates independent gain and phase control. Left-hand or right-hand circular polarization can be supplied to dual feed antennas. Present invention allows each antenna to be independently polarized. Low-cost componentry is utilized throughout. On-board control of the (T/R) module is obtained using a complex programmable logic device (CPLD) and a micro controller. CPLD provides separate control of four phase shifters, attenuators, channel polarization as well as transmitter on/off control. Telemetry is provided through built-in test (BIT) routine.

The invention relates to a hyperspectral image detection system capable of simultaneously acquiring left-hand and right-hand circular polarization components of a target. The system includes a pre-positioned collimation system, a double-refraction beam splitting system, an imaging lens and an image acquisition and processing system that are sequentially arranged in the direction of incoming rays. According to the invention, a double-channel circular polarization detection system is adopted to simultaneously acquire an interference figure of the left-hand and right-hand circular polarization components of a target, the detection system improves the capability of acquiring a difference circular polarization spectral image as compared with the single-channel polarization imaging spectrometer only capable of detecting a single linear polarization component, avoids quiver noise as compared with the sequence acquisition technology adopting a rotary component, can be used for acquiring the circular polarization spectral image of the target within a wide band range from the ultraviolet band to the infrared band, and has potential application values in the fields of space exploration, earth remote sensing, machine vision, biomedical diagnosis and the like.

A time-phase encoding measurement device independent quantum key distribution system comprises a first quantum state preparation end with an Alice time-phase encoding module, a second quantum state preparation end with a Bob time-phase encoding module and a measuring end Charlie, wherein the Alice time-phase encoding module and the Bob time-phase encoding module are the same round-trip structure with a time-phase encoding function and an automatic compensation polarization change function. Compared with the prior art, only a single laser is combined with a reciprocating structure, the problem that the frequencies of two lasers are inconsistent can be solved, meanwhile, channel polarization changes can be automatically compensated, and an active deviation correction module does not need to be adopted. In addition, the arrival time of the two paths of light can be accurately adjusted in a continuous light chopping mode through the light intensity modulator, and a high-precision optical fiber delay line does not need to be used. In addition, the system does not need phase reference system calibration, and the complexity of the system is reduced.

The invention provides a quantum key distribution system irrelevant to polarization coding measurement equipment, which comprises a measurement end Charlie, an Alice reciprocating coding module and a Bob reciprocating coding module, and is characterized in that the measurement end Charlie is composed of a pulse laser, a Bell state measurement device and an orthogonal polarization pulse beam splitting and combining module; the Bell state measurement device comprises a beam splitter BS, a circulator CIR, a first polarization beam splitter PBS1, a second polarization beam splitter PBS2 and four single photon detectors SPD. The orthogonal polarization pulse beam splitting and combining module is provided with a first port, a second port, a third port and a fourth port. Compared with the prior art, the quantum key distribution system irrelevant to the polarization coding measurement equipment only uses a single laser combined with a reciprocating structure, can eliminate the problem that the frequencies of two lasers are inconsistent, can automatically compensate the channel polarization change, realizes stable preparation and transmission of a polarization state, does not need to adopt any active compensation module, the complexity of the system is reduced, and the stability and practicability of the system are improved.

The invention relates to a 2mum coherent wind lidar polarization state matching and correcting system, which comprises a 2mum laser, a first single-mode polarization-maintaining fiber, an acoustooptic frequency shifter, a second single-mode polarization-maintaining fiber, a tail fiber-type Grin lens, a lambda/2 wave plate, a lens, a polarization beam splitter prism, a lambda/4 wave plate, an off-axis optical antenna, a stepper motor drive device, a polarizer, a first tail fiber-type coupling lends, a double-channel polarization state analyzer system, a second fiber beam splitter, a photodiode, a coaxial cable, and an oscilloscope. The system can monitor each polarization state situation of reference local oscillation laser signals and laser echo signals in the coherent wind lidar system in real time. when polarization state of two light beams are not matched, the double-channel polarization state analyzer system can automatically correct the polarization state of the laser until matching is realized, thereby greatly improving the heterodyne efficiency of the coherent wind lidar system and improvising detection sensitivity of the system.

The invention discloses a three-primary-color holographic metasurface based on dual-channel polarization multiplexing and a design method thereof. According to the color hologram of the metasurface, two orthogonal circular polarization channels are used to process three primary color components R, G and B of a color image, corresponding dispersion compensation is carried out for the wavelength of each component, the crosstalk problem of the three primary color components of the color hologram is solved, and the metasurface has the advantages of an angle multiplexing mode and a polarization multiplexing mode. On the basis, a phase-type computer-generated hologram is realized through phase regulation and control of each periodic nanometer unit forming the metasurface, and a color hologram can be presented in a far field under a normal incidence condition. The invention provides a new way for the metasurface color holography, and the metasurface can be applied to the fields of color holographic display and the like.

The invention discloses a non-coaxial four-channel polarization imaging method and system. Aiming at the defects that a current polarization imaging system is low in energy utilization rate, is not high in imaging resolution and cannot achieve the imaging of a remote target and a target in a glimmer environment, the invention proposes and achieves the polarization imaging method which performs multi-channel collection of four different polarization detection angles, and effectively improves the polarization imaging resolution and imaging quality. The specific angles of the four channels and the baseline length in the method can be adjusted according to targets in different environments and at different distances, thereby achieving the purpose of improving the target contrast.

A quantum digital signature system resistant to polarization disturbance comprises a message sender Alice, two message receivers Bob and a receiver Charlie, the sender Alice sends a message to the receiver Bob and the receiver Charlie in combination with a digital signature, the receiver Bob serves as a message authenticator and forwards information sent by the sender Alice to the receiver Charlie, and the composition of the receiver Charlie is completely the same as that of the receiver Bob. Compared with the prior art, the quantum digital signature scheme based on the phase coding BB84 quantum key distribution system can resist channel polarization disturbance. The photon polarization state change caused by channel disturbance does not influence the final interference result of the system, namely, the stability of the system can be ensured.

The invention provides a method, control device and system for performing satellite switching on a motor antenna, which can reduce the time spent by the motor for rotating to a preset position when switching different satellite programs. The method comprises the steps of determining that a current channel and a target channel correspond to satellites with different longitudes according to the readsatellite longitude of the target channel; determining that the polarization mode of satellite launching radio waves for transmitting a target channel signal is first polarization according to a channel polarization mode in parameters of the target channel, and controlling the power supply of the motor according to power supply voltage of a second polarization mode of the antenna, wherein the power supply voltage of the second polarization mode of the antenna is higher than the power supply voltage of the first polarization mode of the antenna; sending a rotation instruction to the motor; andcontrolling the antenna to receive signals according to the first polarization mode when the motor is determined to rotate to the preset position.

The invention relates to an anti-polarization-disturbance phase encoding quantum key distribution system which comprises a sending module and a receiving module. The receiving module comprises an optical fiber circulator, a first polarization beam splitter, a first Mach-Zehnder interferometer, a second polarization beam splitter, a first single-photon detector and a second single-photon detector.The output end of the sending module is connected with the input end of the optical fiber circulator; one output end of the optical fiber circulator is connected with the input end of the first single-photon detector. The other output end of the optical fiber circulator is in bidirectional connection with the input end of the first polarization beam splitter. Two output ends of the first polarization beam splitter are correspondingly and bidirectionally connected with two ends of the first Mach-Zehnder interferometer. The other two ends of the first Mach-Zehnder interferometer are connected with the input end of the second polarization beam splitter. The output end of the second polarization beam splitter is connected with the input end of the second single-photon detector. According to the invention, the influence of channel polarization disturbance on the distribution system is eliminated, and the stability of the distribution system is improved.

The invention relates to a polarization-independent phase codec. Two interfaces of a circulator are respectively connected with a first single-photon detector and a first polarization beam splitter, and a light outlet of the first polarization beam splitter is respectively connected with a light inlet of a third polarization-maintaining beam splitter through a fast axis and a slow axis of a polarization-maintaining optical fiber, a light outlet of the third polarization-maintaining beam splitter is connected with a light inlet of a second polarization beam splitter through a fast axis and a slow axis of the polarization-maintaining optical fiber respectively, a second phase modulator is connected between one path of light outlet of the second polarization beam splitter and an entrance, andone path of light outlet of the first polarization beam splitter is connected with a second single-photon detector. The invention further provides a quantum key distribution system. Compared with theprior art, the requirement for the sending end is low, the structure of the receiving end is simple, the detector comprises H and V components, the interference result cannot be affected by the change of the incident polarization state, polarization is irrelevant, the influence of channel polarization disturbance on the system can be resisted, the bit error rate is reduced, and the key generationrate is increased.

A method for determining features of an error correcting code system, comprising independent error correcting codes and a polarization module, allowing transmitting a binary input vector on block fading sub-channels, the independent error correcting codes generating components of the binary input vector and a channel polarization being applied to the binary input vector by the polarization module. The method comprises: obtaining characteristics of the block fading sub-channels; and, determining features of said error correcting code system, comprising, for each error correcting code, a rate of said error correcting code, adapted to the obtained characteristics and minimizing a function of a probability that an instantaneous equivalent channel capacity of the block fading sub-channels is below a transmission rate transmitted on the block fading sub-channels.

The invention belongs to the technical field of laser spectrum technology application, and provides a self-calibration polarization atmospheric laser radar device and a method, and the device comprises a laser, a linear polaroid, a laser transmitting device, a laser receiving device, a narrow-band optical filter, and a polarization area-array camera. According to the method, on the premise of notadditionally adding an optical element, atmospheric backscattering signals of four polarization states are obtained at the same time, atmospheric echo signal detection equations of the four polarization states are constructed, an accurate body depolarization ratio deltav and an accurate polarization mismatch angle theta are obtained in real time through a nonlinear least square method, and the problem that gain ratio calibration of a traditional dual-channel polarization laser radar system is complex is solved. The device has the characteristics of simple structure, convenience in operation, low cost, high reliability and the like.

Provided is an infrared polarization interference imaging spectrometer based on a double-cycle stepped phase reflector, relating to the technical field of infrared polarization imaging spectral measurement instruments, and solving the problem of the simultaneous acquisition of the polarization information, the image information, and the spectral information in the existing target scene, and the micro-miniaturization and integration of a polarization imaging spectral instrument. The infrared polarization interference imaging spectrometer includes a collimating mirror, a four-channel polarizer,a four-channel imaging mirror, a beam splitter, a plane reflector, a double-cycle step phase reflector, a relay imaging mirror and an area array detector. The optical field coupling between the four-channel polarizer and the four-channel imaging mirror, and the double-cycle stepped phase reflector realizes the modulation of image field polarization and interference, so that a four-channel polarization interference image of the target scene is obtained, the polarization, the image and the spectral information of the target scene can be obtained through one-time scanning, and the imaging spectrometer is small in size, light in weight, simple in structure, high in integration level, high in measurement speed, and multiple in information quantity.

The invention aims at providing a channel polarization secure coding method based on robust soliton distribution, and the method comprises the following steps: firstly, a sending end codes to-be-sentinformation based on robust soliton distribution; then, Polar coding is executed for the to-be-sent information which is coded based on robust soliton distribution; and a normal receiving end and an eavesdropping end respectively perform Polar decoding for the received information, finally, the normal receiving end and the eavesdropping end respectively perform belief propagation decoding for thereceived information subjected to Polar decoding, and restore the sent information. Compared with the existing technology, the method provided by the invention can improve transmission rate of information transmission while guaranteeing security and reliability of information transmission under the premise of slightly increasing secure coding and decoding complexity, and consequently improves validity of information transmission.

The invention relates to a device for correcting the polarization twist of two linearly polarized signals by way of two polarization converters connected in series, wherein the second polarization converter can be rotated about the axis thereof. In this way, the skew angle of an antenna can be compensated with respect to a satellite by way of a rotatable waveguide circuit. By converting the polarization from linear to circular, it is easier to rotate the now circularly polarized signals, which is carried out in a second polarization converter, which again establishes a linear polarization for the circularly polarized signals. Given the dual-channel signal outcoupling, the PCU introduced here allows two orthogonal linear polarizations to be corrected at the same time using a relatively simple mechanical composition.

The invention relates to a polarization imaging system point-by-point calibration method and belongs to the technical field of polarization imaging. A plurality of sets of four-channel polarization images are collected through the polarization imaging system, and the ratio of the intensity of emergent light of an edge view field to the intensity of a center view field is calculated by applying a large-view-field axis external oblique light beam incident polarization imaging theory; the stokes vector of polarized light of the edge view field is obtained according to the normalized stokes vectorof the linearly polarized light of the center view field; then according to an instrument matrix and the relation between the stokes vectors and the channel intensity, a point-by-point instrument matrix of each set of four-channel images is obtained; finally, a least square method is applied to obtain the calibrated point-by-point instrument matrixes. According to the method, the calculated polarization degree and polarization angle information of a polarization imaging system calibrated by the point-by-point instrument matrixes are more accurate and approximate to theoretical values. Therefore, the problem that the precision of a traditional calibration method is insufficient is solved, detection errors of the polarization imaging system are reduced, and the precision of polarization imaging detection is improved.

The invention discloses an automatic measurement system of omnimax atmospheric polarization pattern. The automatic measurement system is characterized by comprising an omnimax information acquisition module, a three-channel polarization module and a control module, wherein an omnimax light source input system outputs an omnimax light beam of an optimal light path to the three-channel polarization module through the omnimax information acquisition module, the three-channel polarization module converts the information category of the omnimax light beam of the optimal light path and outputs omnimax polarization image information to the control module, the control module controls the three-channel polarization module to collect the omnimax polarization image information, and outputs omnimax atmospheric polarization pattern information through stokes vector algorithm processing and calculation. The automatic measurement system can be used for collecting the omnimax polarization image information in three different polarization directions under the same view field and acquiring the omnimax atmospheric polarization pattern information so as to eliminate the error.

The invention provides a multiple-input-multiple-output broadband satellite mobile communication channel modeling method based on a dual-orthogonal-polarization antenna. With five modeling steps of the method, selection of channel model parameters, realization of a Markov process of a mobile communication channel, generation of a time sequence of each Markov state channel, adding of time correlation of a broadband state channel time sequence and superstition of channel polarization characteristics and correlation between antennas are respectively realized. According to the multiple-input-multiple-output broadband satellite mobile communication channel modeling method based on the dual-orthogonal-polarization antenna, broadband characteristics of the channels, such as frequency selection fading, time selectivity fading and broadband Markov state characteristics, are considered, and influence of the channel polarization characteristics and the spatial correlation between the antennas on the channel characteristics after application of the dual-orthogonal-polarization antenna is also considered. The broadband satellite mobile communication channel modeling method is more accurate and comprehensive so that the channel characteristics of multiple-input-multiple-output broadband satellite mobile communication on the basis of the dual-orthogonal-polarization antenna can be more realistically reflected.

An integrated broadband polarization controller is based on planar waveguide technology. The integrated broadband polarization controller emulates the polarization control function of an existing single channel polarization controller in a device that can be built in planar waveguide technology, and is expanded from single channel operation to broadband channel operation by designing the control degrees of freedom to be wavelength selectively addressable.