26 results about "Continuous phase modulation" patented technology

The invention discloses a satellite communication waveform generation method and system based on coding orthogonal frequency division multiplexing and continuous phase modulation, and a storage medium. The satellite communication waveform generation method comprises the following steps: S1, performing low-density parity check coding on input data; s2, performing constellation mapping on the coded data to generate a symbol sequence; s3, performing multi-stage continuous phase modulation on the symbol sequence to obtain a modulated signal; s4, performing selective mapping processing on the modulated signal, and selecting an orthogonal frequency division multiplexing subcarrier signal with the lowest peak-to-average power ratio as a signal to be output; s5, performing inverse fast Fourier transform on the to-be-output signal, adding a cyclic prefix, and outputting a final signal; the method can suppress the peak-to-average power of the signal, and is high in processing efficiency and low in bit error rate.

The invention provides a method and a device for processing a signal, aiming at the problem of poor demodulation performance caused by CPM symbol phase accumulation, the demodulation performance of the CPM symbol can be improved by carrying out differential processing on a modulation symbol input into continuous phase modulation (CPM) at a signal transmitting end and breaking the continuous accumulation of the symbol phase of the CPM by a receiving end through de-differential processing.

The invention relates to a method for processing a received signal derived from two continuous phase-modulated signals, comprising the following steps: frequency shifting (102) of the squared received signal so as to produce: a first and a second shifted signal having a spectrum shifted by D / 2 and -D / 2 respectively with respect to a spectrum of the squared signal, where D is a bit rate of each of the two continuous phase-modulated signals; determination (108): of a first and a second frequency at which a power spectral density of the first and second shifted signals takes a first and second maximum value respectively, of a third frequency at which a power spectral density of the squared signal takes a third maximum value; central tendency measurement of the frequencies to estimate (110) a frequency difference between the received signal and each of the two continuous phase-modulated signals. Figure for the abstract: Fig. 3

The present application provides a signal processing method and apparatus. To address the problem of poor demodulation performance caused by phase accumulation of continuous phase modulation (CPM) symbols, differential processing is performed on modulation symbols for CPM input at a signal transmitting end, and then inverse differential processing is performed at a receiving end to disrupt the continuous phase accumulation of CPM symbols, thereby improving CPM symbol demodulation performance.

The application provides a spatial sound field real-time generation device based on a light-controlled programmable ultrasonic phased array, realizes continuous phase modulation and amplitude control of array elements, does not need to separately configure a high-voltage pulse circuit or an independent amplifier for each channel, thereby guaranteeing the compactness of the system structure and the low power consumption advantage; the light-controlled phase shift unit independently controls the phase of each ultrasonic element by adjusting the light intensity, realizes accurate regulation and control of the wave front direction; the overall layout of the array and the power input are kept synchronous, thereby guaranteeing the controllability of the amplitude and energy output of the ultrasonic field; the application decouples the phase control and the power driving, effectively avoids the complex wiring problem of multi-channel synchronous control, and improves the flexibility and scalability of array operation; in addition, the introduction of the light-controlled mode significantly simplifies the array driving circuit, realizes parallel control of a large-scale array, and thereby forms an ultrasonic field generation device with high compactness, excellent controllability and high flexibility.

The present disclosure provides an iterative receiving method of a polar coded continuous phase modulation signal and a related device. The method comprises: receiving, by a demodulator, a continuous phase modulation signal from a channel, and determining an initial accuracy parameter, a forward metric and a backward metric of the continuous phase modulation signal; performing, by the demodulator, an operation on the initial accuracy parameter to obtain a target accuracy parameter; performing, by the demodulator, a recursive operation on the forward metric and the backward metric based on the target accuracy parameter to obtain a multi-ary code word probability, and obtaining an estimated information stream at a receiving end based on the multi-ary code word probability and converting the estimated information stream into a decoder prior information stream; performing, by a decoder, a decoding process on the decoder prior information stream based on a serial cancellation list decoding algorithm to obtain a candidate code word sequence, performing a decoding process on the candidate code word sequence based on a belief propagation decoding algorithm, and judging whether the decoding process meets a preset termination condition, and outputting a source information bit or a target information stream at the receiving end according to a result of the judgment.

Radio signal for navigation satellites with optimized signal structure, which can be used for position, navigation and time determination, characterized in that the detectability of the signal on the receiver side is optimized by the use of Multi-h CPM (Continuous Phase Modulation) with subsequent optimization of the auto- / cross-correlation of the signal.

This application provides an optical beam combining system and a laser system. The optical beam combining system includes: a superlens array comprising multiple superlens structures; a metasurface array comprising multiple metasurface structures, wherein the number of metasurface structures is the same as the number of superlens structures, and each superlens structure forms an optical path branch with one metasurface structure; and an optical beam combining structure for combining the light from multiple optical path branches into a single output beam. Through the above-described optical beam combining system, continuous phase modulation can be achieved to achieve the effect of optical beam combining.

The invention discloses a high-bit-rate multi-index continuous phase modulation signal receiver which comprises a frequency conversion and conditioning module, an AD daughter card module, a frequency synthesis module, an FPGA chip 1 and an FPGA chip 2. Wherein the frequency conversion and conditioning module is configured to complete down-conversion and AGC (Automatic Gain Control) of an S-band radio frequency signal and output an S-band intermediate frequency signal; the AD daughter card module is configured to convert a received S-band intermediate frequency signal into an intermediate frequency digital signal; the frequency synthesis module is configured to complete system work clock generation; the FPGA chip 1 is configured to complete Doppler frequency capture of a received intermediate frequency digital signal, send the captured signal to the FPGA chip 2, receive a demodulation information sequence fed back by the FPGA chip 2 to complete LDPC decoding, descrambling and frame synchronization of corresponding data, and output telemetry data; the FPGA chip 2 is configured to perform carrier phase tracking, modulation index synchronization, timing synchronization and sequence detection on received data.

Systems, methods, and computer-readable storage media for generating and utilizing radar signals with embedded data are disclosed. Data is encoded onto a CPM waveform, which is then combined with a base radar waveform to produce a radar-embedded communication (REC) waveform. Both the CPM waveform and the base radar waveform may have a continuous phase and constant envelope, resulting in the REC waveform having a continuous phase and constant envelope. The changing (e.g., on a pulse-to-pulse basis) nature of the REC waveform causes RSM of clutter which may result in residual clutter after clutter cancellation, decreasing target detection performance of the radar system. In an aspect, various parameters may be utilized to dynamically adjust the performance of the radar system for a particular operating scenario, such as to enhance radar signal processing or enhance data communication capabilities.

The invention relates to a terahertz transmission array metasurface antenna based on continuous phase modulation, which is formed by arranging N * N metasurface units, and each unit structure comprises a top arc metal corner structure, a middle polyimide dielectric layer and a bottom arc metal strip, the transmission amplitude gt of the 2THz-frequency linearly polarized electromagnetic waves is realized by adjusting the distance between the top-layer metal strips, the length of the bottom-layer metal strips and the corresponding central angle of the arc-shaped structure; and the continuous phase modulation of 0.8 is realized. The unit structure parameters are determined through collaborative design of a neural network and a genetic algorithm, when N is equal to 25 and the focal diameter ratio is 1, the antenna can efficiently convert spherical waves emitted by a feed source at the focal point into plane waves, the far-field gain of the antenna reaches 29.6 dBi, and the aperture efficiency is 52%. The invention has the characteristics of simple structure, easiness in manufacturing and high transmission efficiency, and can be widely applied to the fields of terahertz communication, imaging and the like.

The invention relates to the technical field of digital information transmission, in particular to a continuous phase BPC signal generation method and system based on a direct spread sequence. The method comprises the following steps: performing waveform forming by combining a high level and a first pseudo-random sequence of a plurality of chips to generate a first combined sequence, performing phase modulation on a first signal through information bits to form an in-phase baseband signal, and performing waveform forming by combining the high level and a second pseudo-random sequence of a plurality of chips to generate a second combined sequence, and modulating the second signal by using the information bit phase and selecting a level proportion duration to generate an orthogonal baseband signal, and fusing the in-phase baseband signal and the orthogonal baseband signal to generate a BPC signal. The method has the advantages of amplitude modulation and phase modulation, effectively improves the signal receiving performance, the anti-interference performance, the timing measurement precision of the user terminal and the signal coverage range, introduces continuous phase modulation, can meet the requirement of transmitting equipment for continuous phase change, and ensures that spread spectrum signal energy is fully received and utilized.

The application discloses an ultra-high dynamic range continuous phase compensation system and method for atomic interference, and belongs to the technical field of atomic interference precision measurement. The system comprises a vibration sensing module, a digital processing module, a phase-locked loop control module and a laser modulation module; a Raman mirror vibration signal is collected in real time through an accelerometer, is input into an FPGA after differential amplification and ADC conversion, is sequentially subjected to high-pass filtering, low-pass filtering and weighted integral operation based on an atomic interference time domain sensitivity function, and a phase compensation amount caused by vibration is calculated in real time; the phase compensation amount is converted into an analog compensation signal through a DAC and is injected into a phase-locked loop control link, a phase error signal output by a frequency discriminator is combined, a VCO is controlled, an AOM or an EOM is driven to implement continuous phase modulation on Raman laser in the whole process, and thus real-time, high-precision and high-bandwidth compensation of phase noise caused by mirror vibration is realized, and the system has the advantages of large dynamic range and strong environmental adaptability.

The application discloses a SAR composite phase modulation jamming method based on a phase-adjustable metasurface, and relates to the technical field of signal processing.The phase-adjustable metasurface designed by the application adopts a multi-layer metal base and a design of a butterfly-shaped structure unit, so that the whole structure is compact and easy to be integrated into the surface of a protected target, and a varactor diode is introduced as a control element; by changing the voltage applied to the two sides of the first butterfly-shaped structure unit and the second butterfly-shaped structure unit, the equivalent capacitance of the varactor diode can be controlled in real time, and then the continuous change control of the phase of the incident electromagnetic wave is realized; by only designing the first butterfly-shaped structure unit and the second butterfly-shaped structure unit with high matching degree, and simultaneously controlling the equivalent capacitance of the varactor diodes on the first butterfly-shaped structure unit and the second butterfly-shaped structure unit, the continuous phase modulation of the incident electromagnetic wave is realized, and the modulation accuracy of the control metasurface when modulating the electromagnetic wave is greatly improved, so that the effect of jamming the SAR radar is improved.

This invention relates to a continuous phase modulation secure communication method and system. The communication system of this invention communicates in time slots and employs a combined transmitting and receiving communication device capable of obtaining accurate time synchronization. The method is as follows: First, the communication delay between the transmitting and receiving parties is estimated; then, based on the current time information obtained by the transmitting device, the set time slot length, and the one-way transmission delay between the transmitting and receiving devices, a randomization seed for the time slot is set, and waveform coefficients such as the transmission rate of the original symbol in the time slot, the truncation position and length of the spread spectrum pseudo-random sequence, and the periodic dwell time of the spread spectrum pseudo-random sequence chip are randomized; the original symbol is spread spectrum modulated, and then subjected to a novel continuous phase modulation; finally, the receiving device modulates the received signal, and then generates waveform coefficients consistent with those of the transmitting device based on the obtained current time information, despreads the demodulated signal, recovers the original symbol, and realizes keyless transmission of information.

The invention discloses a constellation design method and device for continuous phase modulation, and relates to the technical field of communication, and the method comprises the steps: carrying out the quantitative analysis of an error pattern of a modulation symbol of a continuous phase modulation system through Monte Carlo simulation, and determining an error probability matrix; determining a plurality of symmetric pairwise confusion metrics of each modulation symbol based on the error probability matrix, performing descending sorting, and determining a symbol pair error set of each modulation symbol; performing tagging mapping on each modulation symbol according to a symbol-tag relationship to obtain a corresponding symbol tag; according to the index sequence of the symbol labels, preset coding bits are distributed to the symbol labels associated with the maximum symmetric pairwise confusion measurement in the symbol pair error sets in sequence based on the minimum bit Hamming distance constraint, and the bit symbol mapping relation is determined in combination with the symbol-label relation. Based on the scheme, the constellation diagram of the CPM system is optimized through quantitative analysis of the symbol error pattern, and the transmission performance of the CPM system is improved.

The invention relates to a method for processing a received signal derived from two continuous phase modulation signals, the method comprising: frequency-shifting (102) the square of the received signal so as to produce a first shifted signal and a second shifted signal having a shifted spectrum of D / 2 and of -D / 2, respectively, relative to a spectrum of the square of the signal, where D is a bit rate of each of the two continuous phase modulation signals: determining (108) a first frequency and a second frequency at which a power spectral density of the first shifted signal and of the second shifted signal takes a first maximum value and a second maximum value, respectively, and determining a third frequency at which a power spectral density of the square of the signal takes a third maximum value; performing a central tendency measure of the frequencies in order to estimate (110) a frequency difference between the received signal and each of the two continuous phase modulation signals.

This invention relates to the field of digital information transmission technology, specifically to a method and system for generating a continuous-phase BPC signal based on a direct-sequence spread spectrum (DSSS) sequence. The method includes generating a first combined sequence by combining a high-level signal with a first pseudo-random sequence of several chips to perform waveform shaping; generating an in-phase baseband signal by phase modulation of the first signal using information bits; simultaneously generating a second combined sequence by combining a high-level signal with a second pseudo-random sequence of several chips to perform waveform shaping; generating an orthogonal baseband signal by phase modulation of the second signal using information bits and selecting a level ratio and duration; and fusing the in-phase and orthogonal baseband signals to generate the BPC signal. This invention combines the advantages of amplitude modulation and phase modulation, effectively improving signal reception performance, anti-interference performance, user terminal timing measurement accuracy, and signal coverage. Furthermore, the introduction of continuous phase modulation meets the requirements of transmitting equipment for continuous phase changes, ensuring that the spread spectrum signal energy is fully received and utilized.

The invention relates to a packaged long-wave infrared super lens and a preparation method thereof, a square silicon substrate is adopted, a silicon cylinder matrix is arranged on the silicon substrate, and the silicon cylinder matrix is formed by arranging a plurality of silicon cylinders at equal intervals, so that excellent mechanical stability performance can be ensured, and meanwhile, good optical performance is kept. Meanwhile, experiments prove that the height range of the silicon cylinder is (5.5-9.5) mu m, the diameter range of the silicon cylinder is (0.8-2.4) mu m, continuous phase modulation of 0-2 pi can be achieved, the average transmittance exceeds 80%, and therefore the optical efficiency of the super lens is improved.

This invention provides a millimeter-wave phased array antenna based on liquid crystal material, comprising a power distribution network integrated on a multilayer printed circuit board and multiple antenna elements. Each antenna element includes a sequentially cascaded coupling feed unit, a liquid crystal microstrip phase shifter, and a radiating phase shifter. The liquid crystal microstrip phase shifter generates a continuously adjustable first phase shift by voltage-tuning the dielectric constant of the liquid crystal. The radiating phase shifter generates a fixed second phase shift by switching current paths. The superposition of the two allows the overall phase shift to continuously cover more than 360°. This invention cascades continuous phase modulation of liquid crystal with discrete phase shifting of PIN diodes, realizing a high-precision, low-loss, and low-cost millimeter-wave phased array antenna on a single PCB, suitable for 5G / 6G communication and satellite internet terminals.

The invention belongs to the technical field of communication and radar sensing integration, and discloses an OFDM-NLFM (Orthogonal Frequency Division Multiplexing-Non-Linear Frequency Modulation) sensing integrated signal design method for free space light sensing and an application of the OFDM-NLFM sensing integrated signal design method. Controllable nonlinear frequency modulation spectrum shaping is introduced into an OFDM frequency domain, a sidelobe adjustable window is adopted to construct a target amplitude spectrum, nonlinear instantaneous frequency is generated through cumulative distribution mapping, continuous phase NLFM modulation of multi-carrier OFDM is achieved, and therefore a communication and inductance integrated signal with the communication modulation capacity and the high-resolution radar detection capacity at the same time is obtained. The invention also provides an OFDM-NLFM (Orthogonal Frequency Division Multiplexing-Non-Local Frequency Modulation) inductance integration method, and effective separation of communication data recovery and radar echo parameter extraction is realized through dechirp correction, OFDM demodulation and NLFM matched filtering. Compared with the traditional sine subcarrier OFDM, the OFDM-NLFM signal provided by the invention has obvious advantages in the aspects of distance sidelobe, weak target detection, distance resolution and dynamic range, and can improve the sensing performance while keeping the communication rate.

The application provides a low-loss reconfigurable artificial surface plasmon transmission line, which comprises a dielectric substrate and a metal structure thereon. The metal structure is composed of periodically arranged first metal units; the first metal unit comprises a rectangular metal with a certain width, a zigzag metal and two varactor diodes, the rectangular metal is vertically placed with the zigzag metal, and the varactor diodes are connected in parallel to the two metal parts; the zigzag metal structure is in a corrugated shape, and the protruding part is a triangle. The low-loss reconfigurable artificial surface plasmon transmission line provided by the application can realize obvious loss reduction, realize continuous amplitude modulation of-1 dB to-40 dB in the Ku band, realize continuous phase modulation of more than 160° in the X band, and is expected to be applied to radio frequency microwave circuits.

The invention discloses a high-order CPM modulation and demodulation method and device based on Gray mapping and precoding, and the method comprises the steps: carrying out the Gray mapping processing of a to-be-modulated signal, and obtaining a unipolar first symbol; performing polarity conversion on the first symbol to convert the first symbol into a bipolar second symbol; and after the second symbol is pre-coded, continuous phase modulation of which the order is greater than or equal to 2 is carried out, and a high-order CPM modulation signal is obtained. According to the high-order CPM modulation and demodulation method and the high-order CPM modulation and demodulation device based on the Gray mapping and the precoding disclosed by the invention, each-order CPM modulation is realized by combining the Gray mapping and precoding technologies, the demodulation complexity of the high-order CPM can be obviously reduced, and the performance of the high-order CPM can be improved.

The invention relates to a dynamic threshold capturing method and system for continuous phase modulation, and the method comprises the steps: 1, enabling a locally generated synchronization sequence to slide relative to a receiving sequence through the self-correlation characteristic of the synchronization sequence, and carrying out the integral calculation of a correlation value in a symbol period; step 2, according to the constant envelope characteristic of the continuous phase modulation signal, calculating the signal quality by using the envelope fluctuation characteristic of the receiving sequence corresponding to the local synchronization sequence in the symbol period; step 3, dynamically selecting a related threshold according to the current signal quality condition; and 4, judging whether the correlation value calculated in the step 1 is greater than the threshold determined in the step 3, if so, successfully capturing, and if not, repeating the step 1. According to the method, the capture probability can be effectively improved, the false alarm probability is reduced, and the system transmission reliability and the communication distance are ensured.

The application provides an independently addressable control device based on a continuously phase-modulated intelligent metasurface, which maps the arrangement position information of a metasurface subunit on the metasurface into a logical address in a control program, thereby independently addressing each subunit and further realizing independent addressable operation of the subunit, so that the subunits in certain areas can be continuously regulated by programming, thereby realizing precise and flexible regulation of the intelligent metasurface and making the control effect better. The device mainly comprises three modules connected in sequence: a signal control module for running a pre-set control program to generate a control signal; a signal processing module for outputting multiple independent continuous analog voltages to the metasurface subunit and addressing each output through a global pointer register; and an intelligent reflecting surface module composed of phase-continuously-adjustable metasurface units arranged regularly on a circuit board.

The invention discloses a unitary space-time modulation and demodulation method and device, electronic equipment and a storage medium, and the method comprises the steps: carrying out the unitary space-time modulation of target data based on a unitary space-time modulation signal constellation set, and obtaining a unitary space-time modulation signal; a first signal in the modulation signal constellation set is generated based on a Hadamard matrix; and converting the unitary space-time modulation signal into an offset quadrature phase shift keying signal, and converting the offset quadrature phase shift keying signal into a continuous phase modulation signal. According to the unitary space-time modulation and demodulation method and device, the electronic equipment and the storage medium, the USTM constellation set head signal is constructed based on the orthogonal characteristic of the Hadamard matrix, the complete constellation set is generated through diagonal matrix design, finally, signal phase continuity is achieved through constant envelope processing, and the peak-to-average ratio can be remarkably reduced.