2197results about "Multiple carrier systems" patented technology

To provide a modulation / demodulation method that can avoid overshoot that occurs during a signal point transition process on a constellation even when the Y-00 encryption communication method is applied to a modulation method used in wireless communication, and a wireless communication device using the method.SOLUTION: A modulation method using the Y-00 encryption communication method by phase modulation of information for wireless communication, includes determining a reference position in a constellation of a previous signal point indicating previously transmitted data, making a certain range determined by the reference position a prohibited area so that a transition path of the signal point avoids passing near the origin on the constellation, determining a relative position of the current signal point from the reference position based on a current running key and currently transmitted data within a range excluding the prohibited area, determining I / Q coordinates on the constellation from the current signal point to generate modulated data, and performing multi-value phase modulation.SELECTED DRAWING: Figure 11

The invention provides a baseband radio frequency signal data feedback processing method based on vector modulation, and the method comprises the steps: firstly receiving a baseband signal data set transmitted by a target radio frequency link in a preset frequency band, and the baseband signal data set comprises a plurality of signal frame original modulation parameters and corresponding radio frequency feedback signal waveforms; calculating a feedback error index composed of a phase offset, an amplitude distortion factor and a spectrum leakage factor according to a radio frequency feedback signal waveform, quantifying a modulation error, carrying out time-frequency domain conjoint analysis on the feedback signal waveform, extracting an error feature vector, inputting the error feature vector into a pre-training model for cross-frame correlation learning, and carrying out the correlation learning; according to the method, a dynamic adjustment parameter sequence containing a time sequence dependency relationship is generated, and finally a closed-loop feedback control link is constructed based on the dynamic adjustment parameter sequence and original modulation parameters, so that precise processing and optimal control of baseband radio frequency signals are realized, and the signal transmission performance is effectively improved.

Provided in the embodiments of the present disclosure are a mapping method for probabilistic shaping and a reception processing method for probabilistic de-shaping. The mapping method comprises: on the basis of a target amplitude probability distribution and a bit to be shaped, acquiring a shaping amplitude bit by means of a first decoder, which is dedicated to a channel code; and mapping the shaping amplitude bit to form a modulation constellation point. In the embodiments of the present disclosure, decoding can be performed according to a target amplitude probability distribution and by means of a first decoder, which is dedicated to a channel code, such that a shaping amplitude bit is acquired, and the shaping amplitude bit is enabled to be close to the target amplitude probability distribution, thereby realizing a relatively small rate loss and a relatively low shaping complexity.

The deep joint source channel coding method comprises the following steps: a sending end obtains a first semantic feature of a first image, and performs constellation mapping modulation on the first semantic feature to obtain a first initial constellation point; the sending end extracts semantic information of the first initial constellation point, generates a rotation angle corresponding to the semantic information, and rotates the first initial constellation point according to the rotation angle to obtain a first rotation constellation point; the sending end generates a real part interleaving matrix and an imaginary part interleaving matrix based on the first rotating constellation point and the real part and the imaginary part of the channel state information, resorts the real part and the imaginary part of the symbol sequence respectively and then recombines the real part and the imaginary part into a complex signal to obtain a first interleaving signal; the sending end transmits the first interleaved signal to a receiving end through a fading channel, and the receiving end receives a second interleaved signal; the receiving end performs semantic reconstruction decoding on the second interleaved signal to obtain a second image; or, the receiving end performs semantic classification decoding on the second interlaced signal to obtain a second image category.

Methods and systems for detecting anomalous software behavior by monitoring frequency spectrums emanating from an electronic device are provided. A method includes storing frequency spectrum profiles for software applications and operational modes on the device. During execution of a software application, the real-time emanating frequency spectrum is measured and compared to the stored spectrum profile for that application and operational mode. Deviations between the real-time and reference spectrums indicate anomalous behavior from unknown software executing. The device determines a deviation exists and performs remedial actions like alerting the user, disconnecting from the network, shutting down, or switching application execution to another device. Frequency profiles are measured for new applications installed and stored to keep the data updated. Monitoring real-time frequency spectrums emanating from a device provides a computationally lightweight technique for detecting malicious software behavior without requiring complex analysis of application code.

The invention relates to the technical field of intelligent communication, and discloses an end-to-end optimization method, a signal constellation geometry and probability joint shaping optimization method in an end-to-end intelligent communication system, and a communication device based on a neural network. According to the method, a transmitter is constructed by using a neural network, and a received signal passes through a two-stage equalization processing system to form an end-to-end optimization framework without assistance of a channel model. The transmitter adopts a modular design, can realize joint optimization of constellation probability shaping (PS) and geometric shaping (GS), and performs joint updating on all trainable parameters of the system based on a total loss function containing an equilibrium error and a decoding error through a back propagation algorithm. According to the invention, computing resources are effectively saved; the two-stage equalization system can accurately compensate channel damage, the realized PS and GS joint optimization can significantly improve the performance of the communication system and reduce the bit error rate, and the method has good performance advantages and practical value in an actual optical fiber communication system.

A wireless communication apparatus and method using probabilistic constellation shaping in connection with modulation. A wireless transmission device may determine a sequence of amplitude symbols from a sequence of information bits using a distribution matcher (DM) configured for probabilistic amplitude shaping. The device may further apply error correction coding to encode an information block corresponding to at least a portion of the sequence of amplitude symbols. And the device may generate a sequence of output symbols for transmission based on the encoded information block. The device may apply interleaving to one or more of the sequence of amplitude symbols, the information block, the encoded information block, or a combination of the sequence of amplitude symbols and the encoded information block, for the generating of the sequence of output symbols.

This disclosure provides methods, devices and systems for encoding data for wireless communication to achieve an amplitude distribution. One implementation includes a method in which probabilistic amplitude shaping is constrained by an energy value and a sequence composition. The implementation may include three phases. In a first phase, the energy value is determined. In a second phase, the sequence composition is determined. In a third phase, the output sequence is determined as constrained by the sequence composition. The methods generate output sequences defining amplitude symbols that are used to encode data for transmission.

Method and device(s) for supporting performance of machine learning based CFR and DPD on multiple digital input signals relating to different frequency bands, respectively, in order to signal condition said signals before power amplification and subsequent transmission in said frequency bands by a wireless communication network. The device(s) obtain said multiple digital input signals as complex valued signals. The device(s) perform feature construction that takes said multiple digital input signals as input and provides constructed feature signals according to predefined constructed feature types as output. Said predefined constructed feature types relate to at least the following per complex valued sample of the obtained complex valued multiple digital input signals the real part of the sample, the imaginary part of the sample and at least one of the absolute value of the sample and the phase of the sample.

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a transmitter device may modify, based at least in part on a secrecy key, an input or an output of at least one of binary scrambling, modulation, or orthogonal frequency division multiplexing (OFDM) tone mapping for a physical control channel signal, resulting in a secured physical control channel signal. The transmitter device may transmit, to a receiver device, the secured physical control channel signal. Numerous other aspects are described.

The invention discloses an optical fiber terahertz communication system optimization method based on artificial intelligence, and belongs to the technical field of communication. According to the method, four-dimensional constellation shaping is constructed by utilizing additional dimensions provided by two independent sidebands, and an end-to-end optimization framework is divided into a training stage and a deployment stage; in the training stage, firstly, an equalizer based on a pruning neural network and an equalized channel model based on a mixed density network are trained in sequence through receiving and transmitting of a random training sequence; then connecting a constellation shaper at a transmitting end with a demapper at a receiving end through an equalized channel model with fixed parameters, thereby considering full-link residual distortion and noise after equalization, and carrying out back propagation gradient to learn a globally optimal four-dimensional joint geometric probability constellation diagram to further approach the Shannon limit; and in the deployment stage, transmission of the bit stream is realized through coordination of the four-dimensional geometric shaping constellation table and the probability distribution obtained in the training stage and an equalizer at the receiving end and a demapper.

A radio-frequency (RF) circuit including: a multi-tone generation circuit configured to generate a multi-tone signal including a plurality of tones; a predistortion circuit configured to predistort the multi-tone signal or a modulation signal and output a predistortion signal; a power amplifier configured to amplify the predistortion signal and output an output signal; and a predistortion modeling circuit configured to model a predistortion model corresponding to the predistortion circuit based on the predistortion signal corresponding to the multi-tone signal and the output signal.

A wireless communication method includes: transmitting, by the AP-STA, an ultra-high reliability (UHR) physical protocol data unit (PPDU), where the UHR PPDU includes one or more physical service data units (PSDUs), the one or more PSDUs are processed according to a user-specific allocation information, the user-specific allocation information includes one or more UHR-modulation and coding schemes (UHR-MCSs) selected from a UHR-MCS set, and the UHR-MCS set includes inherited UHR-MCSs and / or non-inherited UHR-MCSs.

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 10kV medium-voltage power distribution network power line carrier communication method and system based on adaptive OFDM (Orthogonal Frequency Division Multiplexing), and the method comprises the steps that a master station sends a detection frame to a slave station, and the slave station carries out the CE (Channel Estimation), and obtains the CSI (Channel State Information); the method comprises the following steps of: dividing a broadband channel into a plurality of parallel orthogonal subcarriers, and dynamically allocating a modulation mode, a modulation order and a forward error correction (FEC) coding rate for each subcarrier of OFDM (Orthogonal Frequency Division Multiplexing) by adopting a water injection algorithm based on channel state information (CSI); adopting two-stage automatic gain control (AGC) to condition a signal received from a power line; and carrying out dynamic frequency hopping between a frequency band with serious interference and an idle frequency band based on a continuous spectrum sensing result. Compared with the prior art, through the multi-dimensional adaptive technology, the communication system can sense the channel state in real time and dynamically adjust the communication strategy, so that a stable communication link is established in a severe power grid environment.

The embodiment of the invention provides a power control method and a communication device. The method comprises the following steps: generating a data signal subjected to amplitude limiting processing; determining a power offset, the power offset being used for determining a transmission power ratio between the data signal and a first channel, the first channel being a channel bearing the data signal; and determining the target sending power of the first channel according to the power offset. Thus, the sending power ratio between the data signal and the first channel is determined according to the power offset, and then the target sending power of the first channel can be determined, so that the offset, generated on a constellation diagram, of a modulation symbol borne by the data signal due to amplitude limiting processing of the data signal can be compensated; therefore, the misjudgment probability when the receiving end demodulates the data signal can be reduced.

Methods, systems, and devices for wireless communications are described. A user equipment (UE) generates multiple systematic bits for a message, where the systematic bits are nonuniformly distributed over a time period such that a first bit value has a first probability of occurrence during the time period and a second bit value has a second probability that is greater than the first probability of the occurrence. The UE modulates the systematic bits according to an asymmetric modulation rule such that the first bit value corresponds to a first constellation point on a constellation graph and the second bit value corresponds to a second constellation point that is relatively closer to a center of the constellation graph than the first constellation point based on the second probability being greater than the first probability. The UE transmits the message including systematic bits modulated according to the asymmetric modulation rule.

The invention discloses an encrypted communication system and method based on cognitive multi-carrier spread spectrum, and belongs to the field of covert communication. The encryption communication system comprises a transmitting device and a receiving device. The transmitting device comprises a data encryption module, a constellation encryption modulation module, a multi-carrier spread spectrum module, a frequency hopping module and a cognitive power distribution module. The receiving device comprises a band-pass filtering module, a de-hopping frequency module, a de-spreading module, a constellation decryption demodulation module, a data decryption module and a coherent combination module. The data encryption module is divided into an interleaving coding unit and a double-rule reversible cellular automaton encryption unit. The cognitive power distribution module continuously scans a wireless electromagnetic environment and carries out real-time spectrum analysis to give power spectrum density results sensed under all frequency hopping frequency sets. According to the invention, continuous detection and dynamic response to the spatial frequency spectrum state can be realized, and the communication concealment, the anti-interference performance and the resource utilization efficiency in a complex electromagnetic environment are remarkably improved by utilizing the frequency spectrum hole.

The present invention discloses an unified multiple access (MA) based system for uplink transmission of data by multiple users. The system comprises an user interface integrated transmitter modules for transmitting the data from multiple user transmitters over waveforms through a cooperative unified data grid structure including grid points, said unified data grid structure including each user transmitter allocation of a few non-overlapping grid points for loading respective data bearing symbols, with zeros loaded onto unallocated grid points. The user transmitter is configured to transmit a sparsely loaded grid resembling to the unified two-dimensional data grid structure involving data-bearing Quadrature Amplitude Modulation (QAM), where a part of available grid points of the grid as allocated is loaded with QAM symbols and remaining grid points are loaded with zero symbols. A waveform modulator corresponding to user transmitter is also provided in the present system for waveform modulation of said sparsely loaded grid as per the waveforms enabling transmission for multi-antenna reception of the waveforms to a base station or an access point.

The wireless transmission device includes a power amplifier that varies transmission power. An SNR degradation amount calculation unit calculates an SNR degradation amount {QAM} caused by QAM and an SNR degradation amount {APSK} caused by APSK on the basis of input / output characteristics of the power amplifier acquired from an input / output characteristic storage unit, a QAM modulated signal acquired from a QAM modulation unit, an APSK modulated signal acquired from an APSK modulation unit, and the transmission power of the power amplifier. A modulation scheme selection unit acquires a required SNR {QAM} of QAM and a required SNR {APSK} of APSK from a required SNR storage unit, compares “required SNR {QAM}+SNR degradation amount {QAM}” with “required SNR {APSK}+SNR degradation amount {APSK}”, and selects the modulation scheme with the smaller value.

The invention discloses an intelligent seabed energy detection system and method based on visible light communication, and belongs to the technical field of deep sea detection, the detection system comprises a data acquisition system (1) and a visible light communication system (2), the data acquisition system (1) structurally comprises a high-definition camera (11), an underwater sensor (12) and a first analog-to-digital converter ADC (13), the visible light communication system (2) structurally comprises a transmitting end and a receiving end; the detection method comprises the steps of front-end acquisition, signal conversion, signal processing, optical signal transmission and signal restoration. The characteristics of high frequency and large bandwidth of light waves are utilized, the intensity of light is modulated, binary code element signals are converted into optical signals, the optical signals are received through the photoelectric detector for underwater information transmission, efficient and real-time submarine energy monitoring and analysis are achieved, and comprehensive technical support is provided for development and utilization of submarine energy.

Methods, systems, and devices for wireless communications are described. A wireless communication device may receive a communication signal that includes multiple layers. The signal may include at least one layer that is associated with a probabilistic shaping signal. The wireless communication device may apply one or more probabilistic shaping parameters to the communication signal and obtain a preprocessed signal. The application of the one or more probabilistic shaping parameters may include performing one or more matrix decomposition operations to obtain the preprocessed signal and a preprocessed channel estimate. The preprocessed signal and the preprocessed channel estimate may include probability information associated with the probabilistic shaping signal based on the application of the one or more probabilistic shaping parameters. Accordingly, the wireless communication device may demodulate the communication signal based on the preprocessed signal information.

The invention discloses a self-adaptive CPFSK multi-symbol incoherent demodulation method, and belongs to the field of communication signal processing. The implementation method comprises the following steps: initializing a receiving signal and the length of an observation window; performing orthogonal down-conversion on the received signal to obtain a baseband received signal; constructing a local template sequence according to the length of the observation window, and performing baseband modulation to generate a local baseband template signal; according to the baseband receiving signal and a local baseband template signal, constructing an incoherent judgment statistic, and selecting a candidate sequence; classifying the candidate sequences into credible sequences and uncredible sequences by comparing the judgment of the candidate sequences before and after about the same symbol; taking an intermediate symbol of the credible sequence as an incoherent judgment result, and adding one to the position of the symbol to be judged; for an untrusted sequence, the length of an observation window is expanded, a candidate sequence is selected again, an intermediate symbol is used as a new incoherent judgment result, the position of a symbol to be judged is increased by one, iteration is repeated, and self-adaptive multi-symbol incoherent demodulation is achieved.

Provided are a communication method and a communication device, the method comprising: determining a transmission waveform of a signal, the transmission waveform being related to a threshold of a first parameter, the first parameter comprising: a modulation order and a roll-off factor, the transmission waveform is an orthogonal frequency division multiplexing QAM-DFTS-OFDM waveform of discrete Fourier transform spread spectrum of orthogonal amplitude modulation or an orthogonal frequency division multiplexing OQAM-DFTS-OFDM waveform of discrete Fourier transform spread spectrum of offset orthogonal amplitude modulation, and the roll-off factor is determined based on the transmission bandwidth and the number of symbols carried by the transmission waveform. And transmitting or acquiring the signal. In the method provided by the invention, the network equipment or the terminal equipment can determine the transmission waveform of the signal according to the set threshold value of the modulation order and the threshold value of the roll-off factor, so that the output power supporting higher power amplifiers can be obtained, and a larger signal coverage range can be obtained.

Aspects of the present disclosure provide techniques and apparatus for multi-phase frequency modulation. An example method of multi-phase frequency modulation includes determining a phase of a transmit signal based on constellation points; determining a code for frequency modulation based on the phase; generating a plurality of oscillation signals having different phases; efficiently phase-modulating the plurality of oscillating signals having the different phases based on the encoding for the frequency modulation; and selecting one of the plurality of phase-modulated oscillating signals.

A communication apparatus, a communication system, a communication method, and a non-transitory computer readable medium capable of reducing differences among receiving characteristics of a plurality of quadrature amplitude-modulated signals and optimizing the capacity of transmission signals are provided. A communication apparatus (1) according to the present disclosure includes a transmitting unit (2) capable of transmitting a plurality of types of quadrature amplitude-modulated signals, and an addition unit (3) that adds error correction codes to the quadrature amplitude-modulated signals. Further, the communication apparatus (1) includes a control unit (4) that changes the number of bits of the error correction code according to the type of the quadrature amplitude-modulated signal.

A method includes receiving a bit string at a processor, performing an error correction, and causing transmission of a modulated signal. The error correction includes identifying a set of binary strings based on the bit string, mapping each binary string from the set of binary strings to a first abelian group element from a set of first abelian group elements, and applying a generalization of polar codes to the set of first abelian group elements to produce a set of second abelian group elements. The error correction also includes mapping each of the second abelian group elements to an in-phase / quadrature (I / Q) point from a set of I / Q points and identifying real-valued points based on the set of I / Q points, each of the real-valued points representing an I / Q point from the set of I / Q points. The modulated signal has a modulation that is based on the real-valued points.

The invention provides a frequency offset estimation method and device for a digital subcarrier coherent optical communication system, and relates to the technical field of communication. According to the method, when frequency offset estimation is carried out on a received digital subcarrier signal, empirical mode decomposition is carried out on the signal, namely, an eigenmode function derived by a noisy signal is used for carrying out frequency offset estimation on the signal; decomposing the signal into a plurality of eigenmode components and residual components; using different numbers of eigenmode components to reconstruct a plurality of signals with the residual components; through quartile outlier detection and clustering analysis, a reconstruction signal which most meets the requirement is selected in a self-adaptive mode to serve as a final reconstruction result; and finding out the frequency position of a specified point from the reconstructed signal to carry out frequency offset estimation. According to the method, blind frequency offset estimation in a PDM-16 / 64QAM DSCM system can be accurately and stably realized within a certain error allowable range, and the method has the advantages of being small in error, applicable to different roll-off factors, capable of processing large frequency offset and the like.

Methods, systems, and devices for wireless communications are described. A user equipment (UE) generates multiple systematic bits for a message, where the systematic bits are nonuniformly distributed over a time period such that a first bit value has a first probability of occurrence during the time period and a second bit value has a second probability that is greater than the first probability of the occurrence. The UE modulates the systematic bits according to an asymmetric modulation rule such that the first bit value corresponds to a first constellation point on a constellation graph and the second bit value corresponds to a second constellation point that is relatively closer to a center of the constellation graph than the first constellation point based on the second probability being greater than the first probability. The UE transmits the message including systematic bits modulated according to the asymmetric modulation rule.

The invention relates to a 3D-OFDM (Three Dimensional Orthogonal Frequency Division Multiplexing) system working method based on dual-mode index modulation, which comprises the following steps of: firstly, dividing information bits of a sending end into G groups through a serial-parallel conversion bit splitter, further dividing each group of information bits into three parts, respectively selecting a subcarrier activation mode and two constellation mapping symbols, and combining through an OFDM block generator to generate a frequency domain transmission signal matrix; secondly, performing N-point 2D inverse fast Fourier transform on the frequency domain transmission signal matrix, converting the frequency domain transmission signal matrix into a time domain signal, adding a cyclic prefix to the time domain signal by a sending end, performing parallel-serial conversion, and transmitting the time domain signal to a receiving end through a Rayleigh fading channel; and finally, a receiving end carries out N-point 2D fast Fourier transform on the time domain signal to obtain a frequency domain receiving signal, carries out log-likelihood ratio detection based on greedy detection, carries out de-mapping and demodulation, and recovers corresponding sending information bits. According to the method, the detection complexity is greatly reduced, and meanwhile, the bit error rate performance approximate to an ML algorithm is obtained.