16 results about "Rate modulation" patented technology

The invention discloses a ranging communication fusion miniaturized system and method based on single photon detection. The system adopts a time division multiplexing common-path structure, and a ranging pulse sequence and a communication pulse sequence are sequentially transmitted in the same detection period to form a PPM modulation laser pulse chain. A single-photon detector is adopted to receive signals, background light interference is suppressed by combining a narrow-band filter and a time gating technology, and the type and boundary of a pulse sequence are identified through a signal demodulation and discrimination module. When the distance measurement pulse sequence is identified, the distance measurement path realizes distance measurement based on the round-trip time of the distance measurement pulse in the period; when a communication pulse sequence is identified, the communication path demodulates the PPM communication data. The method effectively decouples the contradiction between the distance measurement fuzzy and the communication rate, supports communication pulse high repetition frequency modulation while realizing non-fuzzy distance measurement, improves the distance measurement precision and the communication rate, and is suitable for free space communication, mobile robot platforms and other application scenes.

The present disclosure provides a wake-up signal processing method. The method includes: a network device modulating a first wake-up signal with a low-rate modulation scheme to obtain a low-rate wake-up signal, superimposing the low-rate wake-up signal with an OFDM signal to obtain a superimposed signal, and transmitting the superimposed signal to a terminal device.

The present disclosure relates to a wireless communication system. Specifically, the present disclosure relates to a device and method for supporting modulation symbols at a high chip rate for ambient Internet of Things (Ambient IoT) communication in a wireless communication system.

The invention discloses a high-speed modulation and demodulation method for a dynamic underwater acoustic network, and the method also employs an orthogonal sequence multiplexing modulation and demodulation technology based on a Zadoff-Chu (ZC) sequence, and combines the setting of a cyclic displacement interval to construct a plurality of sub-channels, thereby achieving the multi-path separation, and reducing the average transmitting power of a system at the same time. In the aspect of multi-user access, interference among multiple users is regarded as additive white noise by using quasi-orthogonal characteristics among different ZC root sequences, so that uncoordinated random concurrent access is supported; differential modulation between sub-channels in a symbol is adopted, and the requirement for phase tracking is lowered; and a receiving end converts multipath amplitude information into soft decision information through cyclic correlation spectrum calculation and multipath diversity technologies, so that the calculation complexity is reduced, and the throughput of the time-varying underwater acoustic system is improved while the multi-user access efficiency is improved.

The invention relates to the technical field of metasurface electro-optical devices, in particular to a low-loss mid-infrared electro-optical modulator based on graphene and ITO and a preparation method thereof, SiO2, Al2O3, graphene, TiO2 and ITO are sequentially arranged in the electro-optical modulator from bottom to top, and Si is embedded in SiO2 to serve as a central waveguide. Single-layer graphene and ITO with the thickness of 30 nm are placed in a staggered mode to form a heterojunction, change of carriers in the Si waveguide is caused, and then modulation of the change of effective refraction in the Si waveguide is achieved; besides, the graphene and the ITO form a parallel-plate capacitor, the switching energy of the modulator is reduced, high modulation efficiency is achieved, and finally, metal electrodes are placed on the graphene and the ITO respectively, so that voltage directly controls heterojunction. According to experimental verification, a high extinction ratio is achieved under low insertion loss, and multi-rate modulation can be achieved.

The invention discloses an unmanned aerial vehicle surveying and mapping information transmission management system based on artificial intelligence, and the system carries out the real-time feature extraction of original surveying and mapping data through employing a pruned CNN, and carries out the fusion of multi-modal data through employing a cross-modal editor. A GNN graph neural network is used for analyzing the position, the electric quantity and the channel quality of the unmanned aerial vehicle cluster in real time to establish a dynamic communication topology, and a low-dimensional feature vector and a spatio-temporal feature vector are transmitted to a routing path optimization module based on the dynamic communication topology; a relay node is dynamically determined by taking minimization of end-to-end delay and maximization of network survival time as targets, and a routing path of the unmanned aerial vehicle cluster is optimized; and dynamically adjusting a transmission rate, a modulation mode and channel resources according to a real-time network load and a data priority in the unmanned aerial vehicle cluster after path optimization based on a bandwidth allocation model of DRL deep reinforcement learning. Redundant transmission is greatly reduced, and the bandwidth utilization rate is improved.

The application belongs to the technical field of CO2 storage migration monitoring, and discloses a CO2 storage migration monitoring method and system based on distributed optical fiber acoustic wave sensing. By controlling the time-varying flow rate modulation coding sequence of the injected fluid, the wellbore itself is converted into a controllable virtual phased array sound source distributed along the wellbore. By using the pre-solved frequency-radiation angle mapping relationship, the direction of the acoustic wave energy radiated to the formation can be controlled by changing the frequency of the injected signal, and the directional scanning of the formation around the well is realized. This method does not need to lower a special acoustic logging instrument, reduces the operation cost and risk, and can flexibly adjust the detection angle and range according to the monitoring requirements.

The invention discloses a double-loop pseudo-rate modulation method and device suitable for multi-nozzle configuration. The method comprises the steps that S1, a main loop control comprehensive signal and an auxiliary loop control comprehensive signal are calculated respectively; s2, the control comprehensive signals of the main loop and the auxiliary loop are processed through a correction network, and main loop control duty ratio instructions and auxiliary loop control duty ratio instructions are generated; s3, feedback path signals of the pseudo-rate modulators of the main loop and the auxiliary loop are calculated; s4, converting the on-off state of the attitude control spray pipe into an on-off control instruction, identifying a disturbance torque coefficient on line, and respectively generating a main loop disturbance compensation duty ratio instruction and an auxiliary loop disturbance compensation duty ratio instruction; s5, integrating the control duty ratio instruction, the interference compensation duty ratio instruction and a pseudo-rate modulator feedback path signal to generate a main loop switch control instruction and an auxiliary loop switch control instruction; and S6, according to the distribution of the spray pipes, converting the main loop switch control instruction and the auxiliary loop switch control instruction into a spray pipe switch instruction and a multiplex spray pipe switch instruction respectively, and outputting the instructions to attitude control spray pipes for execution.

A multimodal fusion underwater acoustic wired dual-mode communication system and method, relating to the field of underwater electrical communication transmission technology, addresses problems such as poor signal transmission reliability, disconnect between acquisition, computation, and communication, and the contradiction between power consumption and real-time performance in complex underwater channel environments. The system adopts a dual-core heterogeneous architecture, including modules for data acquisition, signal synchronization, fusion computation, and communication. The communication module is the core collaborative unit, supporting wired and underwater acoustic dual-mode communication. It employs LDPC-OFDM low-error-rate modulation and error correction technology, combined with a redundant storage module to achieve data temporary storage and automatic retransmission in case of link interruption. Through scheduling by the dual-core heterogeneous main control unit, it achieves full-link collaboration between acquisition, computation, and communication, optimizing transmission link selection and data packaging processes, and improving the real-time performance and stability of underwater signal transmission. It achieves low-error-rate transmission in high-noise environments, adapting to complex underwater communication environments such as marine gas leak monitoring and deep-sea earthquake early warning.

The present invention discloses an adaptive optical switching method based on FPGA platform in space optical communication. The present invention adopts dual wavelengths λ1,λ ’ 1 for communication, λ1 is the signal light, which is used to carry the “payload”, λ ’ 1 is the beacon light, whose primary function is to carry a "header" to establish and route space links. It can also provide feedback on the quality of the atmospheric channel, thereby adjusting the rate, routing path, and even the modulation format of the λ1 signal. The relay node allocates paths for light with different functions and sources, some of which enter the electronic control system (FPGA) and some directly enter the optical switch for transmission. This helps improve communication efficiency and resolve problems such as wavelength conflicts and the impact of atmospheric turbulence. This invention solves the problems of automatic routing and adaptive selection of channels, rates, and modulation formats in star networks and cascaded star networks.

The application discloses a magnetoencephalography compatible multi-channel near-infrared high sampling rate modulation method and system, and belongs to the field of multi-modal brain function imaging research.The method comprises the following steps: modulating a driving signal of an fNIRS light source to a high-frequency carrier; adopting a multi-channel frequency division multiplexing strategy, transmitting the modulated driving signal to each fNIRS light source, so that each fNIRS light source emits infrared light rays for detecting a target; and demodulating the detected infrared light rays to obtain the amplitude of the detected infrared light rays.The application can realize non-contact sensing of the target.The application can reduce electromagnetic interference in the process of MEG and fNIRS synchronous imaging, utilize specific frequency modulation technology to realize synchronous acquisition of magnetoencephalography signals and multi-channel high sampling rate near-infrared signals, and accurately and quickly demodulate the near-infrared signals.

Embodiments described herein may be related to optical devices and apparatuses directed to forming waveguides and optical phase modulators that enable high baud rate modulation. In one embodiment, an optical phase modulator includes: photonic optical waveguides having their cladding regions and electrical contacts formed by material with its absolute permittivity near zero (ENZ), and their waveguide core region formed by electro-optical (EO) material or silicon PN junction whose optical refractive index changes with strength of externally applied electrical field. The ENZ material described herein further possesses properties of both optical transparency at operating wavelength and electrical conductivity. The ENZ claddings and electrodes may further have dimensions to enable high externally applied electrical field within waveguide core. The EO material described herein includes but not limited to organic polymers, LiNbO3, liquid crystals. Other embodiments are described and claimed.

The invention discloses a brain magnetism compatible multi-channel near-infrared high-sampling-rate modulation method and system, and belongs to the field of multi-mode brain function imaging research, and the method comprises the steps: modulating a driving signal of an fNIRS light source to a high-frequency carrier; transmitting the modulated driving signal to each fNIRS light source by adopting a multi-channel frequency division multiplexing strategy, so that each fNIRS light source emits infrared light for detecting a target; and demodulating the detected infrared light to obtain the amplitude of the detected infrared light. According to the invention, non-contact perception of the target can be realized. According to the invention, electromagnetic interference in the MEG and fNIRS synchronous imaging process can be reduced, synchronous acquisition of brain magnetic signals and multi-channel high-sampling-rate near-infrared signals is realized by using a specific frequency modulation technology, and the near-infrared signals are accurately and rapidly demodulated.

The invention provides a modularized waveform architecture for communication signal simulation and a simulation method, relates to the technical field of communication countermeasure testing, and solves various limitation problems of a traditional special hardware platform in communication signal simulation. In the architecture, an information source scrambling component receives data to be modulated and performs scrambling processing on the data to be modulated; the channel coding component selects a corresponding coding mode to perform coding processing according to the parameter instruction; the group hopping frame assembly adds a synchronous code to the encoded data to realize framing, converts the framed data according to a corresponding hopping structure in a frequency hopping mode, and outputs the data; the spread spectrum component performs data expansion according to a spread spectrum multiple parameter value issued by configuration and then outputs the data; and the variable rate modulation assembly selects a corresponding modulation mode according to the parameter instruction to complete modulation mapping of symbols, and outputs obtained communication signals after rate control and filtering processing. According to the invention, advantages and effects of waveform dynamic generation and parameter real-time adjustment are smoothly realized.

The invention discloses a variable-rate FSK (Frequency Shift Keying) modulation and demodulation method, device and system based on an FPGA (Field Programmable Gate Array), and belongs to the technical field of FSK modulation and demodulation. Based on the FPGA, the method comprises the following steps of: controlling selection of a frequency word according to data to be sent during signal transmission, controlling updating of the frequency word according to a preset symbol rate, controlling a DDS (Direct Digital Synthesizer) to generate FSK modulation signals with different modulation orders by the frequency word; the operation frequency of the DDS is a modulation signal sampling rate; when a signal is received, a variable multiple CIC decimation filter is firstly used for decimation according to integral multiples, the sampling rate of the received signal is reduced, then Farrow structure fractional multiple decimation filtering is used for adjusting the sampling rate to a first symbol rate, and FSK demodulation and bit synchronization recover data in the adjusted signal. According to the invention, the transmission rate can be dynamically adjusted according to the channel state, the spectrum resource utilization rate is improved, and the transmission performance is improved.