17 results about "Constellation diagram" patented technology

A communication method and a communication apparatus are provided. The method includes: a relay node receiving a first signal, the first signal including a first modulation symbol from a first source node and a second modulation symbol from a second source node, wherein the first modulation symbol includes a symbol mapped on a first constellation diagram, the first constellation diagram having multiple constellation points in the same quadrant, and the minimum distance between two adjacent constellation points in the same quadrant being less than 2k, where k is a constellation mapping normalization factor; the second modulation symbol includes a symbol mapped on a second constellation diagram, the second constellation diagram having no more than one constellation point in each quadrant, and the transmission power of the second modulation symbol being determined based on the transmission power of the first modulation symbol; the relay node then forwards the first signal. By reducing the distance between adjacent constellation points in the same quadrant and re-determining the transmission power, the bit error rate of the first signal received by the relay node is improved, thereby greatly reducing the risk of the relay node eavesdropping on information.

The application discloses a detection synchronization and demodulation design method based on a high-speed burst communication system, comprising the following steps: S1, performing fast acquisition on a burst synchronization sequence in a high-speed QPSK and OQPSK satellite communication system; S2, after the matching flag of the synchronization sequence in S1 is valid, performing M&M frequency offset estimation on current on-the-fly complex signal data and a preset synchronization sequence, generating a corresponding carrier compensation value by using the calculated frequency difference value, and outputting the frequency-compensated on-the-fly complex signal; S3, performing phase estimation on the frequency-compensated on-the-fly signal and the preset synchronization sequence, generating a corresponding phase compensation value by using the calculated phase difference value, and outputting the frequency-phase-compensated on-the-fly signal; and S4, after the frequency-phase compensation is completed, the on-the-fly complex signal is sent into a small-bandwidth synchronization tracking loop to generate a compensation value, a constellation diagram is output, and a symbol hard decision is performed on the loop output to output a synchronization code stream. The application meets the requirements of low bit error rate and missed detection and false detection rate, and provides good demodulation performance.

This invention proposes a b-modulation nonlinear frequency division multiplexing system based on Gaussian mixture clustering, belonging to the field of optical fiber communication system technology. It creatively applies the Gaussian mixture clustering algorithm to the b-modulation nonlinear frequency division multiplexing system, replacing the original hard decision and soft decision algorithms of the b-modulation nonlinear frequency division multiplexing system, to equalize the phase rotation of the received constellation diagram caused by noise, thereby eliminating the influence of spontaneous emission noise from the EDFA amplifier and various adverse factors in the optical fiber channel. At the same time, it performs clustering decision on the demodulated 16QAM constellation diagram data, reducing the bit error rate of the system and improving the system performance.

This invention discloses an adaptive blind demodulation method, system, terminal, and medium based on a satellite communication system. The method includes: performing parameter estimation, frequency offset compensation, and timing synchronization processing on the original baseband sampled data sequence to obtain a single symbol rate data symbol sequence; performing hierarchical phase-locked loop carrier coarse synchronization iterative processing on the single symbol rate data symbol sequence to obtain a target convergent constellation diagram symbol sequence; extracting high-order cumulant features based on the target convergent constellation diagram symbol sequence and performing modulation scheme identification and confidence judgment, iterating until a preset judgment condition is met to obtain a target modulation identification result; and performing adaptive carrier fine phase-locking and blind equalization joint processing on the target modulation scheme to obtain a demodulated symbol sequence. This invention solves the coupling problem between carrier synchronization and modulation identification by combining hierarchical carrier synchronization, high-order cumulant feature identification, and adaptive fine phase-locking blind equalization, thereby improving demodulation reliability.

The application relates to the technical field of wireless communication, and discloses an origin avoidance method, an origin avoidance device, electronic equipment and a storage medium. The origin avoidance method comprises the following steps: firstly, detecting a phase modulation signal, identifying data positions at which a signal trajectory passes through an origin of a constellation diagram, and forming an origin position set; then, for each data position in the set, a signal trajectory direction at the position is acquired, and a correction vector orthogonal to the direction is determined according to the signal trajectory direction, and the correction vector is superimposed on a signal at the corresponding position; after superimposition processing of all data positions in the set is completed, a phase modulation signal after origin avoidance is output. The application can effectively maintain original modulation accuracy while correcting the signal trajectory passing through the origin.

This invention provides an analog joint coding modulation method, apparatus, and device based on amplitude probability shaping. By deeply coupling S-K mapping coding with multi-ring constellation modulation based on amplitude probability shaping, a modulation architecture combining geometric shaping and probability shaping is constructed. The radius of each ring in the constellation diagram is jointly determined by the amplitude scaling factor and the cumulative probability. A uniform phase offset is introduced between adjacent rings to optimize the geometric layout. Then, through joint iterative optimization of S-K mapping coding parameters and constellation amplitude and phase parameters, the signal distortion ratio is maximized. Thus, without increasing system complexity, a single modulation architecture can achieve collaborative adaptive optimization of coding and modulation, significantly improving the end-to-end transmission performance of the system.

This invention discloses an automatic modulation identification method for multimodal fusion wireless signals based on deep learning, belonging to the field of communication technology. First, a publicly available dataset is selected as the channel input data and merged according to modulation type to form a set of time-domain I / Q data. Then, a constellation diagram is created for each set of time-domain I / Q data, and the data and corresponding constellation diagrams are segmented according to the signal-to-noise ratio to form a training set. Next, a multimodal fusion neural network model based on the time-domain I / Q data and constellation diagram data is constructed and input into the training set for iteration, adjusting the learning rate until the network model reaches stability. Finally, a newly acquired radio signal to be identified is input into the trained multimodal fusion neural network model, which automatically outputs the modulation identification type of the wireless signal. This invention can more fully extract the fusion features of the signal in the time domain and the corresponding constellation diagram to optimize the information loss caused by downsampling, thereby obtaining more accurate signal phase and amplitude information.

Disclosed is a method for implementing a rate-adaptive multi-input single-output visible light communication system, where the visible light communication system includes transmit ends and a receiver end. Binary transmission data streams corresponding to the transmit ends are respectively modulated onto a constellation diagram, and all transmit constellations are loaded onto a signal generator after subjected to digital signal processing, the signal generator outputs analog signals, which are respectively amplified by electrical amplifiers, and then coupled to direct current by biasers, and the light sources corresponding to the transmit ends convert the electric signals obtained by coupling into optical signals. The probabilistic shaping is performed on all the transmit constellations respectively so as to enable same to conform to Maxwell-Boltzmann distribution of a QAM constellation; and geometric shaping is performed on all the transmit constellations at the same time to make a transmit signal power of each transmit end equal.

The embodiments of the present application are applied to the technical field of communications. Provided are a communication method, a communication apparatus, and a storage medium, which are used for solving the problem of a constellation diagram having a relatively poor distribution performance after being subjected to superposition. The method in the embodiments of the present application comprises: obtaining a first signal on the basis of X constellation points of a first constellation diagram, wherein X is determined on the basis of a modulation order and the number N of users using a first resource, the first constellation diagram is a lattice-structured constellation diagram, and both X and N are positive integers; and sending the first signal on the first resource. In the embodiments of the present application, a constellation diagram which has been subjected to superposition is directly optimized, and the constellation diagram which has been subjected to superposition is designed by using a lattice structure, thereby improving the performance.

A signal modulation method, a signal demodulation method, and a communication device are provided. The signal modulation method includes: a first device modulating a signal according to a first modulation constellation diagram, which is generated based on channel information. That is, a suitable modulation constellation diagram can be generated based on the actual channel environment, rather than being limited to a limited number of modulation constellation diagrams, thereby improving the performance of the communication system.

In the present disclosure a signal modulation method, a communication device, and a computer-readable non-transitory storage medium are provided. The method may include: modulating M+2 bits of information according to a first constellation diagram model, or modulating M+3 bits of information according to a second constellation diagram model, to obtain modulation symbols, where the first constellation diagram model comprises 4*N constellation points, the second constellation diagram model comprise 8*N constellation points.

The constellation optimization method for terahertz non-ideal channel based on deep learning belongs to the field of terahertz communication.The method of the present application is as follows: a transmitter based on DFT-s-OFDM modulation is designed to generate a transmission signal; a communication system model for terahertz non-ideal channel is established to obtain a received symbol sequence after the transmission signal is transmitted through the channel and processed by a receiver; a constellation optimization model based on a multi-layer neural network is constructed, a joint loss function containing three types of constraint terms is designed, adaptive optimization training is performed on constellation symbols, and an optimized constellation point sequence suitable for terahertz non-ideal channel is obtained; the optimized constellation points output by the multi-layer neural network are screened and constrained, projected and mapped to a standard QAM constellation to obtain a final constellation diagram satisfying the standard modulation format.The present application can reduce the symbol error rate under the condition of terahertz non-ideal channel, improve the robustness of the system to non-linear distortion and phase noise, and simultaneously consider power efficiency and implementation complexity.

The application relates to a constellation geometry shaping system and method for few-mode fiber space division multiplexing, and belongs to the technical field of optical fiber communication and digital signal processing. The system and method are based on a module designed in the system. Firstly, system parameter configuration, initial constellation construction and mode-dependent loss parameter setting are completed in the system initialization layer, and a transmission signal is generated. Then, the signal enters a few-mode fiber microchannel based on a step-by-step Fourier method to complete a signal transmission process. A full-micro digital signal processing link is established at the receiving end to process the signal. In the training track, a joint loss function is constructed based on a multi-mode generalized mutual information, and optimization is carried out in combination with a weighting mechanism. Through automatic differentiation, constellation parameter iterative updating is realized. In the verification track, the channel condition is fixed, the constellation performance is evaluated, and the optimal constellation result is selected. The application can reconfigurably realize mode-dependent loss-resistant geometry shaping of a constellation diagram without changing the existing optical communication transceiver structure.

The invention discloses a data transmission method, a communication node, a medium and a program product. Comprising the following steps: acquiring an original bit sequence, and dividing the original bit sequence into data blocks with a preset length; inputting the data block into a pre-configured auto-encoder, and sending the obtained complex symbol stream; wherein the pre-configured auto-encoder comprises at least one ghost module. According to the method, the auto-encoder directly realizes mapping from binary bits to complex symbols, so that data transmission does not need participation of pilot frequency any more, and data transmission resources do not need to be allocated to the pilot frequency in the data transmission process; and meanwhile, the ghost module can realize direct mapping from bits to complex symbols through low-cost linear operation, and modulation operation based on a constellation diagram is not involved any more, so that network parameters required in a pilot-free transmission process can be reduced, and the calculation complexity and the communication cost are reduced.

The application discloses an electromagnetic target identification method based on interpretable multi-task learning, a storage medium and equipment. First, a multi-task learning network oriented to modulation identification and individual identification is constructed, and after the original signal is input, hyperparameters are set, and the multi-task learning network is trained; a generator outputting a disturbance signal is constructed, the original signal is segmented and an original mask is generated, a disturbance mask is generated through element inversion, and then a disturbance signal is generated; the disturbance signal is input into the trained multi-task learning network, and the probability distribution of the classification result under different tasks is obtained; the prediction probability of the multi-task model on the disturbance signal is taken as a supervision label, a local linear model is trained on the original mask and the disturbance mask, the model weight W g is optimized, and the contribution degree of each subsequence to the explanation is obtained g ; the weight is normalized and mapped back to the original signal length, and based on the constellation diagram, a time-frequency domain signal area which plays a key role in model decision is visualized and labeled.

The application discloses a short code polar code encoding construction method based on polarization spectrum. In view of the problems of existing polar code construction in short packet non-coherent SIMO communication, such as dependence on channel state information and limitation of modulation order, a double-core mixed polar code encoding architecture is established, the Kronecker product of two-dimensional cores and arbitrary order cores is adopted, and high-order modulation of an arbitrary symbol mapping bit number is supported; an ordered weight sequence set is generated by calculating the minimum chord distance vector of a constellation diagram; a polarization spectrum statistic is proposed to describe the distribution of segmented weights after the ordering of code words in each sub-code auxiliary set under the condition of no channel state information; an optimization target is established based on the polarization spectrum, the chord distance and the number of receiving antennas, and the optimal information bit allocation is solved by using dynamic programming. Under the symbol level non-coherent SCL decoding, compared with the 5G NR polar code construction scheme and the coherent transmission scheme, the application significantly improves the block error rate performance and is suitable for short packet communication scenes with high mobility and low pilot overhead.

The present invention relates to a measurement instrument comprising: at least a first and a second input paths, wherein each input path is configured to receive a corresponding measurement signal from a device under test, wherein each measurement signal comprises a number of states; a calculation device connected to the at least first and second input paths, configured to calculate an error vector corresponding to each state of each measurement signal, and to produce an average error vector for each state based on the error vectors of each measurement signal corresponding to the same state; and a display device, adapted to create a constellation diagram based on the produced average error vector for each state.