23 results about "Path gain" patented technology

This invention discloses a deep learning-based channel estimation method for asymmetric all-digital communication systems, comprising: designing an uplink receiving array based on a nested sparse array topology to recover the received signal of the sparse array into a virtual array signal of full dimension; decomposing the obtained virtual signal into a grid part and an off-grid part based on Taylor formula, and designing a two-step-angle estimation net (Ts-AEnet) to estimate the signal angle of arrival; solving a least-squares problem to estimate the signal path gain and reconstructing the downlink channel. This invention proposes an uplink receiving array based on a nested sparse array topology in asymmetric all-digital communication systems, minimizing information loss caused by missing antennas, and proposes a deep learning-based Ts-AEnet angle estimation network, which reduces the complexity of channel estimation while ensuring the system's estimation accuracy.

A receiver includes an analog to digital converter circuit, a phase detector circuit, a digital loop filter circuit, a phase interpolator circuit, and a bias adaption circuit. The analog to digital converter circuit is configured to convert a first signal into a second signal according to a clock signal. The phase detector circuit is configured to detect a phase of the second signal to generate a phase detection signal. The digital loop filter circuit is configured to scale the phase detection signal with a proportional path gain coefficient and a bias value to generate a third signal. The phase interpolator circuit is configured to generate the clock signal according to the third signal. The bias adaptation circuit is configured to accumulate the phase detection signal to generate the bias value.

The invention relates to an unmanned aerial vehicle physical layer secret key secret communication method based on an orthogonal time-frequency space. Comprising the following steps: establishing an unmanned aerial vehicle air-ground communication system consisting of a multi-antenna unmanned aerial vehicle base station, ground single-antenna legal users and ground passive eavesdropping illegal users; obtaining channel estimation vectors of all dominant paths by adopting a three-dimensional structured orthogonal matching pursuit algorithm; the method comprises the steps of obtaining a channel characteristic value of a communication channel through a path gain self-adaptive weighted moving average coding method, carrying out double-bit uniform quantization, carrying out Winnow key negotiation based on dynamic grouping and carrying out SHA-2 hash function confidentiality enhancement, and thus obtaining a physical layer key. According to the method, the channel dimension is converted through the orthogonal time-frequency space technology, the influence of Doppler frequency shift is effectively resisted, the channel reciprocity is improved, the key inconsistency rate is reduced, and the safety and stability of a communication system can be remarkably improved.

Methods, systems, and devices for wireless communications are described. A test apparatus may determine a set of channel path gains and a set of beamforming gains between transmit probes and a device-under-test based on a beam direction of a set of beam directions for testing. The channel path gains may be based on angles of departure from a transmit probe and angles of arrival to the device-under-test. The beamforming gains may be based on an antenna panel configuration and the beam direction. The test apparatus may apply a time varying function input transmit powers for transmit probes based on a beam sweeping across the set of beam directions. The test apparatus may transmit, by the set of transmit probes, signals to the device-under-test based on applying the time varying function to the input transmit powers.

The application relates to a full-polarization-maintaining fiber femtosecond laser based on a mode-locking starting promotion structure. The laser comprises a nonlinear amplification ring mirror with a double-path gain fiber, can realize continuous adjustment of a phase difference, introduces a nonlinear phase shift related to laser pulse intensity, reduces a mode-locking threshold of the nonlinear amplification ring mirror laser, improves self-starting mode-locking capability of the laser, and outputs high-power and high-stability ultrashort pulses; a non-reciprocal phase shift element introduces a linear phase shift bias for clockwise and counterclockwise propagation pulses; a linear arm introduces an optical element with a dispersion compensation function, ensures compactness of the oscillator, is used for outputting pulses, simultaneously provides seed pulse pre-chirp management for subsequent higher-power amplification, and realizes flat wide spectrum. The laser adopts a full-polarization-maintaining fiber structure, has good self-starting mode-locking characteristics, is beneficial to pulse filtering and shaping, and simultaneously has the advantages of compact structure, good stability, high damage threshold, high output power and low noise.

A three-dimensional millimeter wave time-varying channel estimation method and device belong to the field of wireless communication, comprising: establishing a millimeter wave communication system containing array motion; establishing a three-dimensional time-varying channel model considering Doppler effect, analyzing the synthesized signal in the three-dimensional time-varying channel caused by array motion, each column of the synthesized direction matrix being consistent with the array manifold of the planar array, indicating that the linear array in motion can form a virtual planar array; realizing sparse representation of the three-dimensional time-varying channel through linear array motion; recovering the three-dimensional time-varying channel based on the iterative meshless weighted algorithm of array motion; comprising AoAs estimation and path gain estimation. The application overcomes the negative influence of Doppler frequency shift in the time-varying channel on channel estimation, constructs virtual array elements, realizes channel estimation on the three-dimensional millimeter wave time-varying channel through linear array motion, improves channel estimation accuracy, and greatly reduces pilot overhead and algorithm complexity.

This invention relates to a method for secure physical layer communication for unmanned aerial vehicles (UAVs) based on orthogonal time-frequency space. The method includes the following steps: establishing an UAV air-to-ground communication system consisting of a multi-antenna UAV base station, a legitimate ground-based user with a single antenna, and an unauthorized ground-based user passively eavesdropping; obtaining channel estimation vectors for all dominant paths using a three-dimensional structured orthogonal matching pursuit algorithm; obtaining channel eigenvalues ​​of the communication channel using a path gain adaptive weighted moving average coding method; performing double-bit uniform quantization; and enhancing security through Winnow key negotiation based on dynamic grouping and SHA-2 hash function, thereby obtaining the physical layer key. This invention effectively combats the effects of Doppler shift by transforming the channel dimension using orthogonal time-frequency space technology, improving channel reciprocity, reducing key inconsistency rate, and significantly improving the security and stability of the communication system.

Circuit for maximizing the dynamic range in a digital-to-analog signal path (100; 200; 300; 400), comprising: a. an input for receiving an input signal (110; 201; 301; 401); b. a first gain stage (120; 210; 330; 445) coupled to the input, the first gain stage (120; 210; 330; 445) having a first gain setting; c. a second gain stage (140; 230; 370; 460) coupled to the first gain stage (120; 210; 330; 445), the second gain stage (140; 230; 370; 460) having a second gain setting, the second gain stage (140; 230; 370; 460) having an analog gain stage and the second gain setting having an analog gain setting; d. a controller (150; 250; 320; 420) for dynamically selecting the first gain setting to maximize the first gain setting without clipping the input signal and for selecting the second gain setting to achieve a desired signal path gain; and e. an output coupled to the second gain stage (140; 230; 370; 460) for transmitting an output signal (235) having the desired overall signal path gain.

The invention relates to a receiver and a clock data recovery method. The receiver includes an analog-to-digital converter circuit, a phase detector circuit, a digital loop filter circuit, a phase interpolator circuit, and a bias adaptation circuit. The analog-to-digital converter circuit is used for converting a first signal into a second signal according to a clock signal. The phase detector circuit is configured to detect a phase of the second signal to generate a phase detection signal. The digital loop filter circuit is configured to scale the phase detection signal using a proportional path gain coefficient and an offset value to generate a third signal. The phase interpolator circuit is configured to generate the clock signal according to the third signal. The bias adaptation circuit is used for accumulating the phase detection signals to generate the bias value.

The application belongs to the technical field of integrated circuits, and particularly relates to a fourth-order delta-sigma modulator design method and system based on passive stacking. The application cascades a quantizer after a third-order active loop filter, and couples capacitors in parallel on the plate of a capacitor array of the quantizer. Sampling and quantization are performed in each cycle. The quantizer quantizes the output of the current loop filter. After quantization, the plate of the capacitor array naturally forms a residual voltage and stores the coupling capacitors. In the noise injection phase of the next cycle, the quantization error stored in the coupling capacitors in the last cycle is injected into the input end of the quantizer through charge redistribution, is weighted and superimposed with the intermediate signal to form the input voltage of the quantizer, and the main path attenuation coefficient and the coupling path gain coefficient are obtained through charge conservation analysis. A gain compensation factor is preset in the front-stage active integrator to offset signal attenuation, and the capacitor ratio is optimized to realize fourth-order noise shaping. The application does not require additional active circuits, has small area and low power consumption, and improves the signal-to-noise ratio.

The invention discloses a wireless channel capacity optimization method for an intelligent network connection meteorological monitoring vehicle, and the method comprises the steps: building a communication system model suitable for the intelligent network connection meteorological monitoring vehicle in consideration of the Doppler effect; an original MIMO channel is equivalent to a plurality of parallel SISO paths through SVD decomposition, and a channel capacity optimization problem is constructed. An original optimization problem is decoupled into two sequentially processed sub-problems: IRS reflection unit phase shift optimization and base station precoding design. According to the coupling characteristic of the two sub-problems, a closed-form solution of an optimal IRS reflection matrix is obtained by indirectly optimizing path gain, and then the optimal precoding of the base station is solved by adopting a water injection algorithm. The algorithm provided by the invention has higher convergence speed and lower calculation complexity, provides an efficient scheme for IRS phase shift optimization, and can effectively adapt to the time-varying characteristic of a meteorological monitoring vehicle channel.

The present application relates to the technical field of non-line-of-sight target detection, and particularly relates to a RIS-assisted FMCW radar non-line-of-sight target DOA estimation method, which comprises the following steps: constructing a scene model of RIS-assisted FMCW radar non-line-of-sight target detection; performing DOA estimation on the target to calculate the angle information of the target relative to the radar; and proposing an alternating direction multiplier method based on a path gain maximization criterion to optimize the RIS phase shift matrix parameters, which can significantly enhance the received signal strength and quality by regulating the electromagnetic wave propagation environment, maximize the equivalent channel gain of the target path, effectively suppress the multipath interference and noise, make the real direction information of the target in the received signal more prominent, not only significantly improve the signal-to-noise ratio, but also ensure that the structure of the received signal covariance matrix is highly matched with the model relied on by the high-resolution estimation algorithm of the subspace class, improve the accuracy, resolution and reliability of the angle estimation, and improve the real-time performance.

A receiver includes an analog to digital converter circuit, a phase detector circuit, a digital loop filter circuit, a phase interpolator circuit, and a bias adaption circuit. The analog to digital converter circuit is configured to convert a first signal into a second signal according to a clock signal. The phase detector circuit is configured to detect a phase of the second signal to generate a phase detection signal. The digital loop filter circuit is configured to scale the phase detection signal with a proportional path gain coefficient and a bias value to generate a third signal. The phase interpolator circuit is configured to generate the clock signal according to the third signal. The bias adaptation circuit is configured to accumulate the phase detection signal to generate the bias value.

The invention relates to the technical field of integrated circuits, in particular to a voltage-controlled oscillator gain calibration method and circuit, and the method comprises the steps: obtaining a first frequency control word and a second frequency control word, generating a first control voltage signal, and outputting a second control voltage signal; an error control signal is generated by comparing the numerical values of the digital signals to adjust the second control voltage signal until voltage locking is achieved; calculating the ratio of the frequency offset corresponding to the second frequency control word to the absolute value of the voltage difference to obtain a gain value of the voltage-controlled oscillator; associatively storing the gain value and the first frequency control word in a lookup table; and querying the lookup table according to the real-time first frequency control word in the phase modulation process to obtain a gain value so as to adjust the gain matching of the modulation path. The influence of frequency, process, voltage and temperature changes on the gain of the voltage-controlled oscillator is compensated through closed-loop calibration, gain matching of a low-pass path and a high-pass path in the phase modulation charge pump phase-locked loop is maintained, phase errors are restrained, and the reliability of a communication link is improved.

The invention provides a wireless communication link high-fidelity simulation method for a high-dynamic Internet of Vehicles, which comprises the following steps of: performing channel modeling by using a channel simulation platform according to an input network layout, a terminal track, a propagation scene and an antenna mode to generate a time-varying channel coefficient; accurate modeling is carried out on key physical phenomena such as multipath propagation, Doppler frequency shift, path gain and propagation time delay in the Internet of Vehicles, and high-fidelity simulation of channel dynamic change characteristics in a high-mobility scene is realized; a transmitter class object, a receiver class object and a channel class object are constructed based on an object-oriented thought, a plurality of processing modules such as QAM modulation, multi-carrier modulation, pilot frequency design, channel estimation and equalization, frequency offset correction and the like are supported, and good transportability and expansibility are achieved. According to the invention, high-fidelity Internet of Vehicles communication system simulation is realized, a communication transceiver signal processing flow is included, and an efficient fidelity verification platform is provided for design and test of an Internet of Vehicles communication protocol and algorithm.

The application relates to a dynamic power supply system and control method for a radio frequency power amplifier, which comprises an envelope detection module, an envelope mapping module, an S-class power amplifier, a mapping establishment module and a feedback demodulation module. The envelope mapping module converts the envelope of a transmitting signal into a control voltage according to a mapping relationship, and the S-class power amplifier efficiently generates a dynamic power supply voltage proportional to the control voltage to supply power to the radio frequency power amplifier, thereby improving the efficiency of the radio frequency power amplifier. The envelope mapping relationship is provided by the mapping establishment module. The mapping establishment module combines and adjusts the transmitting path gain and the maximum power supply voltage, so that the radio frequency power amplifier works in a predetermined compression state, and the envelope mapping relationship is established according to the constant gain criterion. The application can provide dynamic power supply for the radio frequency power amplifier under a large working bandwidth and a complex working environment, effectively improve the efficiency of the radio frequency power amplifier, and has excellent spurious and near-carrier noise suppression capability.

The application discloses a distributed radar-communication integration method based on time delay-Doppler joint modulation, comprising the following steps: acquiring a radar-communication integration signal received by a receiving end, extracting a communication signal echo and a radar signal echo from the radar-communication integration signal; acquiring target time delay, path gain and Doppler information by using a cross-correlation method according to the radar signal echo; demodulating the communication signal echo by using a turbo iterative maximum ratio combining algorithm to obtain communication data in a time delay-Doppler domain grid; and positioning and measuring the speed of the target by using a chan method according to the target time delay and Doppler information, so as to obtain a target positioning and speed measuring result.

The invention relates to an RIS phase shift optimization and beamforming method and system based on computable channels, and the method comprises the steps: calculating channels from a base station to an RIS and from the RIS to a user based on the positions of the base station, the RIS and the user; establishing an optimization problem by using a maximum channel capacity criterion, and constraining a channel in combination with a position; a Riemannian manifold optimization algorithm and a Riemannian conjugate gradient algorithm are adopted to optimize a phase shift matrix of an RIS reflection unit, and optimal RIS reflection path adjustment is carried out; and the base station and the user obtain an all-digital beam forming matrix by using the adjusted RIS reflection path, and design a hybrid beam forming matrix to optimize the spectrum efficiency. In the invention, the base station calculates the azimuth angle and the path gain of the transmitted beam according to the RIS and the user position, after feedback, the intelligent reflecting surface adjusts the reflecting angle according to the fed-back angle information, and meanwhile, hybrid beam forming is designed at the base station end and the user end, so that the spectrum efficiency of the system can be effectively improved, and the millimeter wave transmission bottleneck is solved.

The invention discloses a wireless communication transmission performance analysis method based on an intelligent reflecting surface. The processing method comprises the following steps: creating a wireless communication model in simulation software or a real environment; extracting multipath components such as path gain through a ray tracing technology; performing channel modeling and completing channel reconstruction according to the multipath component; respectively carrying out accuracy analysis on the time delay and the azimuth angle from time and space angles; and carrying out transmission performance analysis on the wireless communication system in combination with the intelligent reflecting surface. According to the method, the resolution (namely accuracy) of the multipath component (MPC) can be effectively improved, the gain of the intelligent reflecting surface (RIS) on the signal transmission efficiency is proved, the transmission performance of the wireless communication signal can be comprehensively evaluated, and a scientific basis is provided for the optimization design and transmission performance analysis of a wireless communication system.

The application discloses a near-field CSI distributed estimation method for wideband XL-MIMO. Firstly, a center LPU estimates path delay parameters of a center subarray channel, other LPUs quickly extrapolate path delay parameters of other subarray channels, and the estimation results are transmitted to a CPU. Then, based on near-field beam oblique vision and parameter symmetry characteristics caused by a large array and a large bandwidth, the CPU fuses the delay parameters estimated by different subarrays, decouples and independently estimates near-field channel parameters, including angle, distance and range parameters. Then, the CPU transmits the estimated near-field channel parameters back to the LPUs, each LPU independently estimates path gain of the subarray channel, and finally, the LPUs transmit the estimated path gain to the CPU, and then reconstruct the full-dimensional wideband near-field channel. The method overcomes the problems of too large CSI acquisition and calculation complexity and low reconstruction accuracy in the large array and large bandwidth scene.

The invention relates to a channel estimation method of a multi-user communication system based on RIS assistance. The channel estimation method of the multi-user communication system based on RIS assistance comprises the following steps: each user in the communication system sends a pilot signal in sequence, and a base station receives the pilot signal; the base station processes the pilot signal, scans and matches an antenna array vector corresponding to the angle of the RIS channel of the base station, and finds a common support row set; channel estimation from each user to a base station is solved; scanning and matching a planar antenna array vector corresponding to the angle of the RIS user channel, and solving a column support set of each user; solving a path gain coefficient of each base station RIS user; and reconstructing a cascade channel matrix of the users to obtain cascade channel estimation between each user and the base station. The channel estimation method of the multi-user communication system based on RIS assistance has the advantages that the method does not depend on idealized hypotheses and is closer to actual application scenes.

The invention belongs to the technical field of integrated circuits, and particularly relates to a design method and system of a fourth-order delta-sigma modulator based on passive stacking, a quantizer is cascaded behind a third-order active loop filter, a coupling capacitor is connected in parallel on an upper pole plate of a capacitor array of the quantizer, and sampling and quantization phases of each period are connected in parallel. The quantizer quantizes the output of the current loop filter, and after quantization is finished, an upper polar plate of the capacitor array naturally forms residual voltage and stores the residual voltage in the coupling capacitor; in the noise injection phase of the next period, the quantization error of the previous period stored in the coupling capacitor is injected into the input end of the quantizer through charge redistribution, the quantization error and the intermediate signal are subjected to weighted superposition to form the input voltage of the quantizer, and a main path attenuation coefficient and a coupling path gain coefficient are obtained through charge conservation analysis. A gain compensation factor is preset in the front-stage active integrator to offset signal attenuation, and the capacitance ratio is optimized, so that fourth-order noise shaping is realized. An additional active circuit is not needed, the area is small, the power consumption is low, and the signal-to-noise ratio is improved.

This invention relates to the field of learning path recommendation and discloses a personalized learning path recommendation system based on multimodal data analysis. The system includes a multimodal data acquisition module, a state credit assessment module, a path topology reconstruction module, and a modal transcoding and recommendation module. By collecting environmental signals and operational behavior signals to extract features, the system quantifies the instantaneous attenuation of each sensory channel to generate instantaneous cognitive load impedance data. It calculates the Euclidean distance between the knowledge node content source impedance data and the cognitive load impedance data, establishes impedance mismatch penalty term data, and uses it as a negative feedback factor to generate a reconstruction transition probability matrix. The system solves for the sequence with the maximum global path gain in the reconstruction matrix as the prefetched path and triggers multimodal material decoupling transcoding in real time when impedance mismatch exceeds the limit. This invention can dynamically adjust the recommended path according to the individual's cognitive state and achieve sensory load balancing compensation, effectively avoiding cognitive overload and improving learning efficiency.