44 results about "Quadrature amplitude modulation" patented technology

The embodiment of the invention discloses a data processing method for optical communication and a related device, which adopt inner code coding with higher gain to improve the performance of cascade coding, can be better compatible with DP-16QAM (quadrature amplitude modulation) and DP-QPSK (differential phase shift keying) modulation, and can be favorably applied to high-baud-rate long-distance transmission scenes such as 800G and 1.6 T-ZR. Specifically, firstly, a first bit set is obtained, the first bit set comprises d1 bits, d1 = 244664 * L, and L is a positive integer. Then, first FEC coding is carried out on the first bit set to obtain a second bit set, the second bit set comprises d2 bits, every 244664 bits in the first bit set are subjected to first FEC coding to obtain every 261086 bits in the second bit set, and d2 = 261086 * L; next, adding dpad filling bits to the second bit set to obtain a third bit set, dpad being an integer greater than or equal to 0; and performing second FEC coding on the third bit set to obtain a fourth bit set.

The invention discloses a transmission type communication system and method based on low-frequency carrier waves and high-frequency modulation. The transmission type communication system and method are suitable for complex medium environments such as deep sea, strata and biological tissues. Aiming at the contradiction that the traditional low-frequency communication bandwidth is insufficient and the high-frequency communication penetrating power is poor, according to the scheme, a low-frequency carrier wave (30Hz-100kHz) and a high-frequency modulation signal (such as OFDM (Orthogonal Frequency Division Multiplexing) and 256QAM (Quadrature Amplitude Modulation)) are fused through a nonlinear signal superposition technology to generate a composite carrier wave signal, long-distance penetration is realized by utilizing the low attenuation characteristic of the low-frequency carrier wave, and meanwhile, the data rate is improved through high-frequency modulation. Application scenes comprise deep sea detection (300-meter high-definition video return), a brain-computer interface (implantable antenna transmission neural signal) and an intelligent power grid (underground pipe network monitoring). Through the physical layer-information layer collaborative design, the physical boundary limitation of traditional communication is broken through, and high penetrability, high bandwidth and strong anti-interference capability are achieved.

An enhanced link adaptation (eELA) method includes receiving, by a responding device from a requesting device, a physical layer protocol data unit (PPDU) including an eELA request message, determining, by the responding device, an eELA feedback message comprising unequal quadrature amplitude modulation (UEQM) information across a plurality of spatial streams based on at least the number of spatial streams derived from the eELA request message or the PPDU, and transmitting, from the responding device to the requesting device, the eELA feedback message. The UEQM information indicates an effective Signal-to-Noise Ratio (SNR) per spatial stream or a derivative of the effective SNR per spatial stream.

The invention discloses a hollow-core optical fiber communication method and system for reducing complexity, and the method comprises the steps: obtaining original bit data, and mapping the original bit data to an initial constellation diagram through a quadrature amplitude modulation mapping algorithm; rotating the initial constellation diagram according to a preset rotation angle to obtain a first constellation optimization diagram, adjusting the first constellation optimization diagram by using a sparrow search algorithm to obtain a second constellation optimization diagram, converting the second constellation optimization diagram into a transmission signal, and transmitting the transmission signal to the receiving end through a hollow-core optical fiber; performing data preprocessing on the received transmission signal to obtain a de-noised signal, performing phase recovery on the de-noised signal based on a quadratic algorithm to obtain a second constellation optimization graph, and performing de-mapping on the second constellation optimization graph to re-convert the second constellation optimization graph into original bit data; according to the invention, the complexity of digital signal processing is reduced, and the accuracy and efficiency of phase recovery are obviously improved, so that the performance of a coherent optical communication system based on the hollow-core optical fiber is comprehensively improved.

The invention relates to the technical field of visible light positioning, and provides an end-to-end indoor visible light positioning method and system based on pilot frequency sequence characteristics, and the method comprises the following steps: transmitting a visible light signal through an orthogonal frequency division multiplexing and orthogonal amplitude modulation mode, and extracting a pilot frequency sequence; extracting local spatial features of the pilot signals and converting the local spatial features into sequence embedding features; time sequence modeling is carried out on the embedded features, and key features are extracted; performing full connection and nonlinear mapping on the key features, and retaining original features through residual connection; and a Kolmogorov-Arnold network is utilized to carry out positioning. Aiming at the problems of channel estimation dependence, high calculation complexity, high data demand, low signal-to-noise ratio, poor adaptability and the like in the existing indoor visible light positioning system, the real-time performance, the robustness and the calculation efficiency of the system are improved based on end-to-end deep learning indoor positioning of the pilot signal fusion LumiLocNet network.

The invention discloses a multi-band modulation signal generation method based on OQAM, and a frequency spectrum wireless transmission method and system. The method comprises the following steps: a transmitting end performs OQAM preprocessing and modulation on original data flow to realize subcarrier multiplexing; and the receiving end is used for sampling the received signal, and down-conversion, demodulation and original data recovery of the signal are completed through a DSP (Digital Signal Processor) processing module. The multi-subcarrier staggered orthogonal amplitude modulation technology is combined, the spectrum efficiency is effectively improved, interference among subcarriers is avoided, and efficient spectrum utilization, low-cost transmission and multi-user access are achieved.

The invention discloses an encryption transmission method in satellite communication, and belongs to the technical field of encryption. The method comprises the following steps of: partitioning satellite communication data, splitting each data block according to odd and even bits, respectively constructing an odd-bit encryption key and an even-bit encryption key, encrypting corresponding data sub-blocks, and restoring the encrypted data sub-blocks into initial encrypted data blocks; and then generating a shift number according to the encrypted sub-blocks, performing shift processing on the initial encrypted data block, and finally performing quadrature amplitude modulation to obtain a satellite transmission signal. Through the multi-step and multi-dimensional encryption mode, the encryption strength of the satellite communication data is remarkably improved, and the security of data transmission is enhanced.

The invention discloses an OFDM (Orthogonal Frequency Division Multiplexing) communication method, device and system, and the method comprises the steps: generating a transmission frame which comprises a plurality of OFDM symbols; a first OFDM symbol of the transmission frame is a synchronous pilot symbol, and a second OFDM symbol is a reference pilot symbol; based on the transmission frame, configuring at least two demodulation modes according to channel conditions or communication requirements; when the first demodulation mode is configured, the receiving end performs differential phase shift keying differential demodulation on subsequent data symbols based on the reference pilot symbols; and when a second demodulation mode is configured, the receiving end performs channel estimation by using the reference pilot symbol, and performs quadrature amplitude modulation equalization and demodulation on subsequent data symbols according to a channel estimation result. According to the invention, ultralow pilot frequency overhead can be realized, the pilot frequency overhead is compressed to only two symbols, a synchronization sequence and a reference pilot frequency sequence in each frame, and the frequency spectrum utilization rate is greatly improved.

This application provides a short-range wireless communication method and a related device. The method includes: generating a transmission frame. The transmission frame includes a frame header and a data domain, phase shift keying modulation is used for the frame header, and quadrature amplitude modulation or phase shift keying modulation is used for the data domain. The method includes sending the transmission frame. In this application, the phase shift keying modulation is used for the frame header of the transmission frame, and the phase shift keying modulation or the quadrature amplitude modulation with a same bandwidth is used for the data domain.

A sourceless co-packaged optical-electrical chip can include a plurality of different optical transceivers, each of which can transmit to an external destination or internal components. Each of the transceivers can be configured for a different modulation format, such as different pulse amplitude, phase shift key, and quadrature amplitude modulation formats. Different light sources provide light for processing by the transceivers, where the light source and transceivers can be configured for different applications (e.g., different distances) and data rates. An optical coupler can combine the light for the different transceivers for input into the sourceless co-packaged optical-electrical chip via a polarization maintaining media (e.g., polarization maintaining few mode fiber and polarization maintaining single mode fiber), where another coupler operates in splitting mode to separate the different channels of light for the different transceivers according to different co-packaged configurations.

A data transmission system includes a transmitter circuit. The transmitter circuit receives regular data bits and auxiliary data bits. The transmitter circuit encodes a first subset of the regular data bits to generate a first subset of encoded data comprising pairs of symbols that are used in quadrature amplitude modulation. The transmitter circuit encodes the auxiliary data bits and a second subset of the regular data bits to generate a second subset of the encoded data comprising at least one pair of symbols that are unused for encoding by the quadrature amplitude modulation. The transmitter circuit generates a modulated output signal that indicates the first and second subsets of the encoded data using pulse amplitude modulation.

The application discloses a kind of optical fiber communication method and system based on anti-pattern gorilla algorithm, comprising: obtaining original bit data to be sent;Original bit data is mapped to constellation diagram by quadrature amplitude modulation mapping algorithm and converted into optical fiber transmission signal;Optical fiber transmission signal is transmitted to receiving end by few-mode channel;The received optical fiber transmission signal is converted into receiving bit data by analog-digital conversion, and receiving bit data is decomposed into leading receiving information and text receiving information;Mode coupling matrix and mode transmission matrix are generated from leading receiving information using anti-pattern gorilla algorithm;Text receiving information is corrected using mode coupling matrix and mode transmission matrix to obtain correction signal, and correction signal is demapped and converted into original bit data again;Reduce the waste of computing resources caused by mode equalization technology and the equalization deviation caused, improve the quality of quadrature mode signal transmission.

The application discloses a layered quadrature amplitude modulation multiple access method without serial interference cancellation. User bits are mapped to constellation points of different levels, and the Euclidean distance between constellation points in each level is set according to the channel gain of the user, that is, the power of each user is adjusted. Finally, after superposition of multi-level constellation points, hierarchical constellation points are formed to carry the bits of multiple users. On this basis, multiple working configuration points are set, and one or more working configuration points are selected to complete the transmission task according to the number of users in the current transmission and the rate requirement of the user. The transmitter sends the corresponding position of each user in the bit string mapped by the constellation point, the Euclidean distance between the constellation points in each level and the corresponding origin in the complete constellation diagram to the receiver, and if multiple working configuration points are selected, the working configuration point matching information can enable the user to achieve the maximum capacity limit of the downlink multi-user transmission service without serial interference cancellation.

According to a first embodiment, a method may include transmitting to at least one user equipment at least one configuration of channel quality indication comprising at least one indication of whether downlink transmissions associated with 16-quadrature amplitude modulation is supported. The method may further include receiving, based upon at least one condition being satisfied, from the at least one user equipment, at least one extended channel quality indication report.

The application relates to a kind of coherent detection space light cooperation transmission methods based on local oscillator elastic light splitting, belong to space light communication technical field.The method includes: in optical transmitting terminal, bit sequence is modulated into optical signal using quadrature amplitude modulation method, then is divided into multiple channel uncorrelated sub-signals for broadcast transmission through fixed optical splitter;In optical receiving terminal, the signal transmitted by even-numbered link is phase-shifted through 90 degree phase shifter, and the phase orthogonality of even-numbered link and odd-numbered link signal is realized;At the same time, through elastic optical splitter, local oscillator light power is adaptively allocated to the photodetector corresponding to each link;The bit sequence is restored after the output signal of photodetector is demodulated through coherent receiver.The power distribution of elastic optical splitter is controlled by voltage controller, wherein the output voltage of voltage controller is dynamically determined according to the state of atmospheric channel by DDPG algorithm.The application can flexibly cope with the influence of different atmospheric channel conditions on transmission performance.

Methods and systems for improved data transmission using audio transmissions are provided. In one embodiment, a method is provided that includes receiving an audio transmission at. Audio symbols may be identified within the audio transmission, and a magnitude and phase for each of the symbols may be identified. Based on the magnitudes and phases, corresponding data values may be identified for each of the audio symbols and may be combined to form a data payload of the audio transmission.

The present invention discloses a method for reducing PAPR in an F-OFDM system, which relates to the technical fields of electronic information and digital signal processing, and includes the following steps: S1: Divide the spectrum into M sub-bands; S2: Perform quadrature amplitude modulation on the input signal respectively and then perform subcarrier mapping to obtain M output signals; S3: Divide the time-domain data after the inverse discrete Fourier transform of the M output signals into V groups, each group containing M / V sub-band signals with a length of N; S4: Sum the sub-band signals in each group through complex addition; S5: Generate a cyclic shift vector of length K [s1, s2, …, s k , and a total of K V phase combinations are generated; S6: Superimpose the phase combinations to obtain corresponding candidate signals; S7: Calculate the PAPR values of all candidate signals, and select the candidate signal with the smallest PAPR value for transmission; By generating candidate signals, the present invention reduces the PAPR value in the system and improves the PAPR suppression performance.

The application discloses a simple receiving multiple access method based on symbol and bit stream joint distribution, first, a transmitter distributes symbol streams and bit streams of each user based on a hierarchical quadrature amplitude modulation constellation diagram; different interference management schemes are adopted for inter-user interference in different beams and inter-user interference in the same beam to inhibit the influence of inter-user interference on system performance; channel equalization processing is performed on signals received by each user receiver, each user calculates log likelihood ratios of each bit stream allocated to each user according to a bit stream distribution result, and the calculation result is sent into a channel decoder to obtain original bit data. The above method jointly optimizes symbol and bit stream distribution schemes of each user and constellation diagram design, and can realize efficient user access in a large-scale access scene while satisfying a constraint condition of signal processing complexity of the receiver.

The invention relates to a coherent detection spatial light cooperative transmission method based on local oscillator elastic light splitting, and belongs to the technical field of spatial light communication. The method comprises the following steps: at an optical transmitting end, modulating a bit sequence into an optical signal by adopting a quadrature amplitude modulation method, and then dividing the optical signal into a plurality of channel-irrelevant sub-signals through a fixed optical splitter for broadcast transmission; at a light receiving end, the signals transmitted by the even-numbered links are subjected to phase shifting through a 90-degree phase shifter, and phase orthogonality of the signals of the even-numbered links and the odd-numbered links is achieved; meanwhile, local oscillation optical power is distributed to the photoelectric detectors corresponding to the links in a self-adaptive mode through an elastic optical splitter; and an output signal of the photoelectric detector is demodulated by the coherent receiver to restore a bit sequence. The power distribution of the elastic optical splitter is controlled by a voltage controller, and the output voltage of the voltage controller is dynamically determined according to the atmospheric channel state through a DDPG algorithm. The method can flexibly cope with the influence of different atmospheric channel conditions on the transmission performance.

The present invention discloses a privacy-preserving orthogonal amplitude modulation method for wireless distributed learning. The method is aimed at processing floating-point data in communication between a central server and a client: the client uses random sparsification processing of shared random numbers to reduce the amount of data transmitted; then, modulated data is obtained after random encoding and orthogonal amplitude modulation using probability parameters in random sparsification; the modulated data is sent to the central server via wireless communication, and then binary demodulated data is obtained after orthogonal amplitude demodulation. The demodulated data is decoded using probability parameters in random sparsification using shared random numbers to obtain restored data of the client's updated data. The present invention can effectively improve communication efficiency while meeting the requirements of privacy protection and accuracy, and effectively solves the two major challenges of privacy protection and communication efficiency faced by distributed learning in wireless communication scenarios, and the accuracy shows good robustness to the signal-to-noise ratio.

Various aspects of the disclosure generally relate to wireless communication. In some aspects, a wireless communication device can receive a wireless communication signal. The wireless communication device can process the wireless communication signal using a digital post-distortion receiver based at least in part on performing a multi-level coding (MLC) set partitioning operation, where performing the MLC set partitioning operation includes partitioning a quadrature amplitude modulation constellation set by limiting a maximum Euclidean distance of errors associated with decoding one or more least significant bits. Numerous other aspects are provided.

The application provides a configuration method, a receiving method, a device, equipment and a storage medium. The method comprises the following steps: determining a modulation and coding strategy (MCS) set based on a high-level configuration parameter; and configuring the MCS of data based on the MCS set. The high-level configuration parameter indicates whether a 16 quadrature amplitude modulation (16QAM) mode is supported in data transmission. The MCS set comprises one or more of the following: a first MCS set and a second MCS set.

The present invention provides a joint detection and decoding method and apparatus for a polar code coded multi-input multi-output (MIMO) system. The method comprises: in a MIMO system using polar code coding and multi-ary quadrature amplitude modulation, setting an initial radius and a bit flip threshold, and searching in a search space in a detection order from the N / mth layer to the first layer, with the initial radius determined based on the noise variance; during the search process, pruning search paths that do not meet a first preset condition, determining the first search path that meets the first preset condition as the reference path; and pruning search paths that meet a second preset condition until a valid path is output as the path with the shortest Euclidean distance to the received signal, and obtaining a decoding result based on the valid path. Based on depth-first spherical detection and decoding, the present invention implements bidirectional pruning by setting an initial radius and a bit flip threshold, thereby improving the error correction performance and convergence speed of the detection and decoding.

Methods and systems for improved data transmission using audio transmissions are provided. In one embodiment, a method is provided that includes receiving an audio transmission at. Audio symbols may be identified within the audio transmission, and a magnitude and phase for each of the symbols may be identified. Based on the magnitudes and phases, corresponding data values may be identified for each of the audio symbols and may be combined to form a data payload of the audio transmission.

The present invention provides a decoding method for a low-density parity-check (LDPC) coded and decoded multiple-input multiple-output (MIMO) system, including: in an LDPC coded and decoded and multi-carrier quadrature amplitude modulation (MQAM) MIMO system, performing detection based on expectation propagation. For the current outer loop, the detection module updates and outputs cavity information after a second preset number of detection iterations according to the sum of the parity-check information output by the decoding module after a first preset number of decoding iterations in the previous outer loop. The decoding module updates and outputs parity-check information after a first preset number of decoding iterations according to the cavity information output by the detection module after a second preset number of detection iterations, and uses it as the input for the first detection iteration of the detection module in the next outer loop. By retaining the parity-check information output after decoding iterations, the present invention ensures the continuity of messages of the entire receiver, and greatly reduces the complexity of the entire system on the premise of improving the system performance to a certain extent.

The present invention discloses an encryption transmission method in satellite communication, belonging to the field of encryption technology. First, the satellite communication data is divided into blocks, and each data block is split according to odd and even bits to respectively construct odd-bit and even-bit encryption keys. After encrypting the corresponding data sub-blocks, they are restored to the initial encrypted data blocks. Then, a shift number is generated based on the encrypted sub-blocks, and the initial encrypted data blocks are subjected to a shift process. Finally, the satellite transmission signal is obtained through quadrature amplitude modulation. Through this multi-step and multi-dimensional encryption method, the encryption intensity of satellite communication data is significantly improved, and the security of data transmission is enhanced.

The invention belongs to the technical field of signal processing, and provides a modulation mode identification method and device based on wireless signal comprehensive characteristics, and the method comprises the steps: obtaining the comprehensive characteristics of a target from a wireless signal, the comprehensive characteristics comprising at least one of a time domain characteristic, a frequency domain characteristic and a time-frequency domain characteristic; under the condition that the comprehensive feature meets a feature judgment threshold and a signal-to-noise ratio threshold corresponding to the target modulation type, determining the target modulation type as a modulation mode identification result; wherein the candidate modulation type comprises at least one of 2ASK, 2 / 4 / 8FSK, MSK, 2 / 4 / 8PSK, OQPSK, Pi / 4DQPSK and 16QAM (Quadrature Amplitude Modulation). According to the method provided by the invention, the modulation mode identification accuracy of the wireless signal is improved.

The invention provides a quadrature oscillator based on super-structure waveguides, the whole oscillator is formed by sequentially connecting three parallel super-structure waveguides (1.1) and a crossed super-structure waveguide (1.2) end to end, an inner square resonant ring and an outer square resonant ring are formed, and the corner connecting positions of the resonant rings are connected through corner connecting structures (1.3). And a negative resistance unit (1.4) is arranged between the two parallel microstrip lines (2.1) of the corner connecting structure. Through the dispersion regulation and control function of the metamaterial waveguide, the problem of index tradeoff between quadrature phase precision and phase noise of a traditional quadrature oscillator is solved, and high phase precision and low phase noise indexes are achieved at the same time. The invention has the advantages of simple processing and simple structure, and has very high application scenarios in orthogonal amplitude modulation and multiple-input-output radar systems.

A ground-high altitude platform-satellite (G-H-S) laser communication system and method based on anisotropic non-Kolmogorov turbulence are provided, and the system includes a ground transmitting terminal, a HAP, a satellite terminal, a ground-HAP uplink and an HAP-satellite uplink. When laser beams are transmitted upwards from the ground transmitting terminal and through the HAP, the laser beams are affected light intensity scintillation, beam drift, and angle of arrival fluctuation, and are transmitted through vacuum channels and received by receiving antenna of the satellite terminal. The HAP is located at stratosphere, and an anisotropic non-Kolmogorov turbulence model is suitable for analyzing turbulence effect in stratosphere. Thus, the anisotropic non-Kolmogorov turbulence model is used to research transmission characteristics of the laser beams. Meanwhile, a hexagon quadrature amplitude modulation (HQAM) is used in the G-H-S laser communication system, which optimizes system performances on basis of improving communication quality, and enhances stability of communication links.

A sourceless co-packaged optical-electrical chip can include a plurality of different optical transceivers, each of which can transmit to an external destination or internal components. Each of the transceivers can be configured for a different modulation format, such as different pulse amplitude, phase shift key, and quadrature amplitude modulation formats. Different light sources provide light for processing by the transceivers, where the light source and transceivers can be configured for different applications (e.g., different distances) and data rates. An optical coupler can combine the light for the different transceivers for input into the sourceless co-packaged optical-electrical chip via a polarization maintaining media (e.g., polarization maintaining few mode fiber and polarization maintaining single mode fiber), where another coupler operates in splitting mode to separate the different channels of light for the different transceivers according to different co-packaged configurations.