415 results about "Signal gain" patented technology

The dynamic monitoring system for the senile cardiac patient comprises a multi-mode sensor module, a data processing module, an analysis module and an alarm module. The multi-modal sensor module collects parameters to generate a multi-modal physiological signal; the data processing module generates a preprocessing signal; the analysis module performs real-time analysis on the pre-processed signal based on a preset elderly electrocardiogram characteristic model to generate a graded alarm instruction; the alarm module triggers corresponding local reminding, remote notification or first-aid linkage response according to the graded alarm instruction, wherein the first-aid linkage response automatically sends the patient position and key physiological data to a specified first-aid center through the first-aid communication module; wherein the self-adaptive adjustment of the multi-mode sensor module comprises the step of dynamically optimizing signal gain according to a skin contact state. According to the dynamic monitoring system for the senile cardiac patients, the problems that dynamic monitoring of the senile cardiac patients is poor in real-time performance, high in false alarm rate and delayed in first-aid response can be solved.

The invention relates to an unmanned aerial vehicle emergency communication spectrum scheduling method and system based on dynamic entropy optimization, and the method comprises the steps: 1, constructing an emergency communication system, and calculating the gain of a received signal; 2, constructing a spectrum sensing and user access model; step 3, evaluating the channel quality in the emergency communication system; 4, establishing a state, an action and a reward of deep reinforcement learning according to spectrum sensing, a user access model and channel quality evaluation; 5, constructing a deep reinforcement learning model, and performing training to obtain a trained deep reinforcement learning model; and step 6, obtaining an optimal strategy of unmanned aerial vehicle emergency communication spectrum scheduling in a spectrum environment by using the trained deep reinforcement learning model, and realizing multi-user aggregation spectrum access. According to the invention, through intelligent distributed spectrum management, the problems of limited spectrum resources and energy, multi-user dynamic competition and the like in a disaster rescue scene are solved, and the spectrum utilization efficiency and the communication reliability are remarkably improved.

The invention relates to the technical field of dual-mode Bluetooth chips, and discloses a radio-frequency signal gain control method and device for a low-power-consumption dual-mode Bluetooth chip, and the method comprises the steps: carrying out the RSSI detection and VSWR measurement of a radio-frequency signal of the low-power-consumption dual-mode Bluetooth chip, and obtaining a radio-frequency signal AC component and a radio-frequency signal DC component; performing bandwidth expansion on the alternating current component of the radio frequency signal, and performing power calibration on the direct current component of the radio frequency signal to obtain reconstructed radio frequency signal data; signal tracking ST time-frequency mapping is executed, the amplitude change rate, the phase deviation and the frequency drift of the radio frequency signal are extracted through a dynamic sampling mechanism, and nonlinear characteristic data are generated; and establishing a radio frequency parameter control network, executing AGC and ALC collaborative optimization calculation, generating a gain control sequence, and outputting radio frequency signal gain control parameters. According to the method, signal distortion and interference in the mode switching process are effectively reduced, and the reliability and stability of gain control are ensured.

The invention provides a transformer substation switch cabinet partial discharge detection method and system based on a sensor, and relates to the technical field of discharge detection, and the method comprises the steps: deploying an ultrasonic sensor according to a sensing collection channel, accessing a signal processing terminal, and configuring a sensor sensitivity threshold value and a signal sampling frequency; adjusting the signal gain of each monitoring node coordinate corresponding to the sensing acquisition channel, synchronously recording the monitoring time, the monitoring node coordinates and cabinet body temperature parameters, and setting a monitoring association control matrix in combination with a sensor sensitivity threshold and a signal sampling frequency; determining a partial discharge type and discharge intensity based on the signal processing terminal; and generating a discharge characteristic distribution map, and generating a partial discharge detection report in combination with the insulation performance index of the substation switch cabinet, a safe discharge threshold and a pulse frequency threshold. The technical problems that in the prior art, a transformer substation switch cabinet partial discharge detection method is poor in anti-interference capacity and low in recognition precision are solved.

The invention relates to the technical field of signal processing, and provides an intelligent sensing device electromagnetic interference suppression method and system based on AI identification, and the method comprises the steps: obtaining a multi-source electromagnetic signal set of a target intelligent sensing device in a preset monitoring period, and carrying out the electromagnetic interference feature extraction processing of the multi-source electromagnetic signal set, performing interference mode matching processing on the electromagnetic interference characteristic set based on a preset interference suppression model to generate an electromagnetic interference suppression strategy of the intelligent sensing equipment; the electromagnetic interference suppression strategy comprises a frequency band adjustment direction corresponding to an interference frequency band distribution characteristic, a signal gain compensation direction corresponding to an interference intensity fluctuation characteristic and an anti-interference filtering direction corresponding to an interference source correlation characteristic; and performing interference suppression operation on a signal acquisition module of the intelligent sensing equipment according to the electromagnetic interference suppression strategy so as to reduce the electromagnetic signal distortion rate of the intelligent sensing equipment.

The invention belongs to the technical field of metal crack detection, and discloses a metal microcrack ultrasonic detection method, which comprises the following modules: an ultrahigh frequency composite array probe with a center frequency dynamic adjustable range of 5-50 MHz; the dual-mode excitation and receiving module is used for independently generating a pulse reflection mode excitation signal and a diffraction mode chirp frequency modulation signal; the phase-controlled synthetic aperture dynamic focusing module is used for realizing + / -60-degree deflection and sub-wavelength level focusing of acoustic beams; the nonlinear harmonic enhancement module is used for exciting a crack nonlinear effect by superposing 1-2MHz fundamental waves; and a time-space-frequency three-domain data fusion module. According to the method, signal-to-noise ratio collapse caused by the diffraction effect in a traditional method is overcome, more importantly, the system has low-frequency penetrability and high-frequency resolution at the same time due to 80%-120% of broadband coverage of chirp frequency modulation signals, the diffraction signal gain is increased by 20 dB or above, a near-surface blind area is compressed to be within 0.2 mm, and the system can be applied to the field of radar imaging. And the core pain point of missing detection of the near-surface microcracks of the thin-wall component is solved.

Provided in the present disclosure are a patch antenna, an antenna array and a communication device. The patch antenna comprises: a feed circuit, a slotted ground plane, and a first patch layer, a second patch layer and a third patch layer, which are sequentially stacked in the direction of the slotted ground plane facing away from the feed circuit and are spaced apart from each other, wherein the feed circuit comprises two feed ports and an open-loop annular feed portion connecting the two feed ports; the slotted ground plane is located on one side of the feed circuit; the slotted ground plane is provided with a plurality of slots; the slotted ground plane is spaced apart from the feed circuit; the orthographic projections of the slots on the feed circuit at least partially overlap the open-loop annular feed portion; and the first patch layer comprises a first patch, the second patch layer comprises a second patch, and the third patch layer comprises a first annular patch. The simplification of the structure of a polarization switchable antenna, the reduction of the return loss and the increase of the signal gain and impedance bandwidth are facilitated.

The invention relates to the technical field of sound box synchronous playing, and discloses a Bluetooth earphone and sound box synchronous playing method and system supporting stereo synthesis, and the method comprises the steps: carrying out the digital sampling of an input audio signal, and obtaining high-frequency digital audio data and low-frequency digital audio data; performing scanning and stereo function identification on peripheral equipment based on a Bluetooth 5.0 protocol to obtain a target audio equipment list; distributing a main data buffer area and a standby data buffer area; distributing the high-frequency digital audio data to Bluetooth earphone equipment for transmission, distributing the low-frequency digital audio data to sound box equipment for transmission, and when detecting that clock drift among equipment exceeds a preset target value, adjusting a reading rate of a main data buffer area for clock synchronization to obtain an equipment synchronization state; and the signal gain and the equalization parameter of the equipment are dynamically adjusted, and the target synchronous playing audio is output, so that the accurate distribution of the high-frequency data and the low-frequency data is realized, and the overall playing effect of the system is improved.

The invention discloses a multichannel parallel level conversion circuit test system, which relates to the technical field of circuit test and comprises a test host, a multichannel parallel level conversion circuit, a signal source module, a signal acquisition module, a control module and a display module. The test host performs test logic verification on the whole process of the circuit test, the multichannel parallel level conversion circuit serves as a target circuit to be subjected to circuit test, a test signal of the circuit test is generated according to the signal source module, and a test case of the test signal is constructed. The signal acquisition module acquires an output signal of the multichannel parallel level conversion circuit, and generates a circuit tuning output signal after signal gain, signal noise optimization and frequency band filtering, the control module performs circuit testing on a target circuit according to a test case and the circuit tuning output signal, and finally, the control module performs circuit testing on the target circuit according to the test case and the circuit tuning output signal. And the display module visually displays the test result.

A voltage meter includes a sampler, a gain circuit, an accumulator and a feedback circuit. The sampler samples an input signal to generate a series of first signals and a series of second signals. The gain circuit, coupled to the sampler, modifies at least one of the series of first signals and the series of second signals, to generate a series of modified first signals and a series of modified second signals. The accumulator, coupled to the gain circuit, accumulates an operational result of the series of modified first signals and the series of modified second signals, to generate an accumulation result. The feedback circuit, coupled between the accumulator and the sampler, sends a feedback signal back to the sampler according to the accumulation result.

The present disclosure provides an image sensor and a high dynamic range adaptive imaging method wherein the image sensor comprises: a pixel array comprising a photodiode acquisition circuit arranged in an array and photogenerating an image charge signal in response to incident light, the photodiode acquisition circuit comprising a dual conversion gain transistor and a row selection transistor; the pre-reading module is used for receiving initial sampling of the pixel photoelectric response signal before the reading stage and comparing the initial sampling with a threshold signal to generate a control signal; the reading module is used for driving the photodiode acquisition circuit according to the control signal and only reading the pixel electric signal under the selected path for output; and the synthesis module is used for generating a path label corresponding to the pixel electric signal and synthesizing a picture. According to the invention, the method can achieve the quick pre-reading judgment before the reading stage, thereby determining the optimal signal gain mode for output, effectively improving the frame rate, reducing the power consumption, and achieving the optimization of a dynamic range.

The invention provides a closed container leakage detection method, device and system, and belongs to the technical field of signal processing, and the method comprises the steps: receiving a first audio signal collected by a microphone array disposed in an outer side space of a closed container, and determining a first angle range of the microphone array according to the audio characteristics of the first audio signal; collecting multiple paths of second audio signals in the first angle range; performing primary beamforming on the multiple paths of second audio signals to determine a third audio signal when the signal intensity is the strongest; and judging whether leakage exists in the closed container according to the signal gain between the third audio signal and the reference audio signal. According to the method, the device and the system for detecting the leakage of the closed container, provided by the invention, the non-dead-corner leakage detection of the detected container on a production line can be quickly realized by carrying out self-adaptive frequency range and intensity range scanning beam forming on the microphone array, the detection precision is higher, the detection cost is lower, and the production efficiency is effectively improved.

An integrated circuit (IC), comprising: a first gain stage configured to apply a first gain to a first signal to generate a first amplified signal; a first converter configured to convert the first signal to a first output signal; a first output pin for outputting the first output signal; gain update circuitry configured to: output a first internal gain control signal to the first gain stage to update the first gain of the first gain stage, subsequently output a first external gain control signal to a second output pin of the IC, wherein output of the first external gain control signal is delayed relative to output of the first internal gain control signal by a first predetermined delay, the first predetermined delay to compensate for signal chain delay between the first gain stage and the first output pin.

The invention discloses an electromagnetic ultra-permeable membrane for wireless signal enhancement, and belongs to the technical field of electromagnetic regulation and control. The electromagnetic super-permeable membrane is composed of a large number of equilateral metal grid units and a flexible transparent PET film substrate. Each metal grid unit is of a square metal structure with a plurality of adjustable metal section lines in the middle, and transmission phase and amplitude modulation of incident electromagnetic waves can be achieved by changing the side length of the structure and the length of the middle metal section lines. The ultra-permeable membranes are arranged on the two sides of the transparent glass plate respectively, and the whole formed by the ultra-permeable membranes and the glass can achieve macroscopic regulation and control of incident electromagnetic waves so as to enhance wireless signal coverage. The visible light transmittance of the ultra-permeable membrane exceeds 85%, the ultra-permeable membrane can cover the beam adjustment range of-150 degrees to 150 degrees or above, and the signal gain peak value exceeds 30 dB; signal enhancement of a plurality of communication frequency bands can be realized by adjusting the structural parameters of the unit structures.

A hybrid multiport array antenna comprises a plurality of columns of hybrid dipole unit cells, each of the hybrid dipole unit cells having a first dipole of a first type, and a second dipole of a second type, wherein the first dipole of the first type and the second dipole of the second type are configured to receive a single pair of RF (radio frequency) signals, the pair of RF signals having two orthogonal polarization states, wherein the first dipole of the first type and the second dipole of the second type are spaced with an offset in a vertical direction. The arrangement of the hybrid dipole unit cells reduces the phase center distance between the dipoles in each column and between columns, thereby assuring high gain while reducing grating lobes and other signal gain degradations caused by longer distances between phase centers.

The invention relates to the technical field of power systems and communication, and discloses an intelligent power grid data transmission system and method of a narrowband Internet of Things, and the system comprises a network coverage enhancement module, a low-delay data processing module, a low-power-consumption management module, and an intelligent load management and data analysis module. The method and the device are used for realizing the stability of data transmission in a signal-limited environment. By introducing the multi-network hybrid transmission architecture and deploying the intelligent antenna and the small base station, the signal coverage range and the transmission stability can be remarkably improved in a signal limited or complex environment, and the multi-network hybrid transmission architecture can determine an optimal network according to real-time signal quality, delay and packet loss probability, so that the stability and the reliability of data transmission are ensured, and the data transmission efficiency is improved. The beam forming of the intelligent antenna and the optimized arrangement of the small base station effectively solve the problem that the signal of the traditional NB-IoT is weak in a building dense area or a remote area by improving the signal gain and the coverage depth.

Systems and techniques are described for wireless communications. For example, a network device can receive, via receive antennas, signals transmitted from one or more devices. Each receive antenna is within one group of two or more groups. The network device can adjust, using gain control modules, a power level of each signal to produce power adjusted signals. The gain control modules are within one group of the two or more groups. At least a portion of the gain control modules is associated with different gain states. The gain states are based on at least one of distances of the one or more devices from the network device or power levels of the signals transmitted from the one or more devices. The network device can process the power adjusted signals.

The invention discloses a self-adaptive system for various gas sensors and a parameter calculation method of the self-adaptive system, and belongs to the technical field of gas detection. The system comprises a front-end polarity adaptation unit, a current-voltage conversion unit, an intelligent neural network calculation unit U5 and an analog-to-digital conversion unit U4, wherein the front-end polarity adaptation unit is used for being connected with a gas sensor and receiving a current signal of the gas sensor; the signal subjected to front-end polarity matching and current-voltage conversion is subjected to signal filtering and signal gain amplification through the intelligent neural network calculation unit U5, analog quantity and digital quantity conversion is performed through the analog-to-digital conversion unit U4, the detected gas voltage value of the gas sensor is obtained, and the intelligent neural network calculation unit U5 calculates the current gas concentration. The multi-gas detection device adapts to gas sensors of different manufacturers, different principles and different measuring ranges, and intelligent self-adaption of multi-gas detection is achieved on the premise that the product cost is not increased; and accurate concentrations can be calculated for different gases.

The invention discloses a voltage-controlled oscillator with a wide frequency regulation range, relates to the technical field of radio frequency, and aims to solve the problems of narrow and discontinuous output frequency tuning range of an oscillator in the prior art. The voltage-controlled oscillator comprises a passive topology module, an active negative resistance module, a frequency regulation module and a mode switching module, the passive topology module comprises a plurality of mutually coupled inductors; the plurality of inductors are coupled together and provide a required impedance peak; the plurality of inductors comprise a splayed inductance coil, a first annular inductance coil and a second annular inductance coil; the inverted V-shaped inductance coil comprises a first inductance coil, a second inductance coil and a public inductance coil; the frequency adjusting module is used for adjusting the corresponding frequency of the impedance peak; the active negative resistance module is used for providing signal gain for the passive topology module to meet oscillation conditions, and the mode switching module is used for switching working modes of the oscillator. The oscillator has four continuous working frequency bands, and the tuning range of the output frequency is wider.

The invention relates to an LEO satellite signal processing method based on an adaptive threshold, and the method comprises the steps: receiving a target low-orbit satellite signal based on a preset signal receiving strategy, and caching the target low-orbit satellite signal through a preset sliding window mechanism, determining a signal amplitude mean value variation, a signal variance mean value variation and a signal to interference plus noise ratio mean value variation of the current signal cache window and the previous signal cache window; if the target low earth orbit satellite signal is judged to meet a first signal adjustment condition according to the signal variance mean value variation and the signal to interference plus noise ratio mean value variation, adjusting the signal gain of the target low earth orbit satellite signal by using a first PID controller, otherwise, adjusting the signal gain of the target low earth orbit satellite signal by using a second PID controller; and when it is determined that the target low-orbit satellite signal satisfies a second signal adjustment condition according to the signal-to-interference-and-noise-ratio mean value variation, adjusting signal interference of the target low-orbit satellite signal by using a second PID controller, and outputting an optimized low-orbit satellite signal after the adjusted low-orbit satellite signal satisfies a preset output condition.

The invention discloses a method for realizing intelligent gain adjustment of a 4G signal and a 5G signal of a wireless repeater, relates to the technical field of wireless network equipment, and solves the technical problems that the gain cannot be dynamically and intelligently optimized according to an actual signal environment, and the network coverage effect and the user experience are influenced. Based on base station configuration and link environment parameters, reasonable gains are accurately calculated, so that gain adjustment better meets actual signal requirements, weak coverage and complex scenes are distinguished, differentiated step lengths are set, different scene signal characteristics are adapted, gain adjustment effectiveness is improved, a'adjustment-monitoring-analysis-iteration 'complete closed loop is constructed, and signal quality is monitored after adjustment. In case of abnormality, a comprehensive analysis signal is generated and optimized and adjusted again, and through mechanisms such as mean value comparison and step length adaptation, the optimal gain adjustment effect is ensured, the network is prevented from being influenced by abnormal adjustment, and the adaptability of the repeater to a complex environment and the network coverage stability are improved.

The invention provides a signal gain self-adaptive control method based on dynamic feedback, which relates to the technical field of self-adaptive control, and comprises the following steps: carrying out initial gain control on an input signal to obtain a system output signal; the feedback quantity of the system output signal is collected, and the filtered actual output signal is obtained through filtering processing; based on the expected output signal and the actual output signal, calculating multi-order errors, including an amplitude error, a first-order derivative error and a second-order derivative error; calculating a collaborative weighting function according to the multi-order error; constructing a comprehensive error cost function based on the multi-order error and the collaborative weighting function; according to gradient information of the comprehensive error cost function and a product term of a second derivative error and a collaborative weighting function, updating a gain parameter by adopting a dynamic step length; and performing gain control on the input signal by using the updated gain parameter to obtain a new system output signal. According to the invention, dynamic self-adaptive adjustment of signal gain parameters can be realized, so that the response capability of the system to rapid dynamic change is improved.

The invention provides an optical gain and electro-optical modulation integrated device and a preparation method thereof, and relates to the field of photoelectron, the optical gain and electro-optical modulation integrated device comprises a chip platform, and an electro-optical modulator and a gain waveguide which are integrated on the chip platform, and the chip platform is doped with rare earth ions in a region corresponding to the gain waveguide; the electro-optical modulator is used for modulating an input optical signal to obtain a modulated optical signal; and the gain waveguide is used for amplifying the modulated optical signal under the action of the pump light and the rare earth ions to obtain a target optical signal. The electro-optical modulator and the gain waveguide are integrated on the chip platform, cooperative work between the electro-optical modulator and the gain waveguide is achieved through rare earth ions, integrated design is achieved, the defects of discrete devices are overcome, and the design target of an on-chip photonic system can be met.

The invention provides an electric power meter data real-time analysis and abnormity early warning method based on edge calculation, and belongs to the technical field of data analysis and early warning, and the method comprises the steps: collecting the multi-modal data of an electric power meter based on a multi-channel analog-to-digital converter, employing a hardware filter circuit to eliminate high-frequency noise, and obtaining the data of the electric power meter; signal gain self-adaptive adjustment is carried out based on a reconfigurable amplifier; a digital signal processing accelerator is used to carry out Fourier transform on a matrix constructed by the standardized data stream, and a multi-core processor is combined to carry out analysis to generate a feature vector; the method comprises the following steps: acquiring environmental parameters in real time based on an environmental sensor, dynamically adjusting an anomaly detection threshold in combination with a machine learning model trained by historical data, and comparing a feature vector with the dynamic threshold to generate an anomaly signal; the relay control circuit triggers sound-light alarm, the physically isolated communication module sends an early warning instruction to the cloud platform, and meanwhile, the redundant power supply module is started to control the electric power meter to operate continuously. And the efficiency and accuracy of subsequent abnormity early warning are improved.

A voltage meter includes a sampler, a gain circuit, an accumulator and a feedback circuit. The sampler samples an input signal to generate a series of first signals and a series of second signals. The gain circuit, coupled to the sampler, modifies at least one of the series of first signals and the series of second signals, to generate a series of modified first signals and a series of modified second signals. The accumulator, coupled to the gain circuit, accumulates an operational result of the series of modified first signals and the series of modified second signals, to generate an accumulation result. The feedback circuit, coupled between the accumulator and the sampler, sends a feedback signal back to the sampler according to the accumulation result.

The invention relates to the field of aeronautical material detection, and discloses an aeronautical material detection method and system.The method comprises the steps that an ultrasonic detection signal is obtained, and frequency characteristic analysis is conducted on the ultrasonic detection signal to obtain a frequency spectrum; based on the frequency spectrum, the system can judge the source information of the ultrasonic detection signals, so that the ultrasonic detection signals with background tendency and the ultrasonic detection signals with defect tendency are distinguished; aiming at signals from different sources, the invention innovatively adopts a differential gain processing strategy: low gain is applied to the signals with background tendency to effectively inhibit the intensity of the signals; high gain is applied to signals with defect tendency so as to ensure that even weak real defect signals can be fully amplified and identified; performing defect judgment on the ultrasonic detection signal subjected to gain processing; the problems that misjudgment is introduced by the signal gain compensation module due to probe sensitivity attenuation and normal background signals and real defect signals are difficult to distinguish can be effectively solved.

The invention provides a noise suppression and gain control method for a high-frequency signal, and relates to the technical field of adaptive control, and the method comprises the steps: collecting a high-frequency target signal and an environment reference signal through a dual-path parallel input channel; performing filtering processing on the high-frequency target signal by using an adaptive band-pass filter; carrying out weighted correlation detection on the filtered high-frequency target signal and the environment reference signal, calculating a correlation degree through a dynamically updated weight coefficient, and identifying effective signal components; performing gain control on the signal by adopting a Newton iteration method based on a second derivative, wherein the gain control comprises two stages of step-by-step coarse tuning and continuous fine tuning; signal-to-noise ratio monitoring is carried out at the output stage, and a monitoring result is fed back to the adaptive band-pass filter and the gain control link, so that bidirectional coupling closed-loop control is formed. According to the invention, the high peak noise in the high-frequency signal can be effectively suppressed, and the signal gain is kept in a proper range.

The invention provides a drip metering method for an ultrasonic water meter, which improves the metering precision of the water meter by accurately measuring tiny changes in water flow, particularly drip events, and comprises the following steps: firstly, a sensor of the ultrasonic water meter acquires water flow signal data in real time, including flow information, flow fluctuation and water flow state, and transmits the data to a signal processing module; through noise removal, signal gain adjustment, waveform amplitude detection and other processing, a system compares the data with a set threshold value, identifies a water dripping event, calculates a flow fluctuation difference value and judges the occurrence of a water dripping behavior, and finally, the system records detailed information of the event and stores the detailed information in a memory for subsequent query. Through the precise signal processing and water dripping event recognition method, the recognition precision of the low-flow water dripping event is effectively improved, missing report and false report are avoided, meanwhile, recording of detailed information and efficient data storage are supported, data integrity and accuracy are ensured, and the intelligent level and practicability of the water meter are improved.

The invention relates to a radio frequency front-end transmitting link and a state detection method thereof, the transmitting link adopts four-stage series power amplification circuits, and the four-stage series power amplification circuits comprise a first-stage power amplification circuit, a second-stage power amplification circuit, a third-stage power amplification circuit and a fourth-stage power amplification circuit; the first-stage power amplification circuit is composed of a first pi attenuator and a low-noise amplification chip and used for radio frequency small signal gain amplification. The second-stage power amplification circuit is formed by cascading a temperature compensation attenuator, a filter and a gallium arsenide power amplifier tube, and the filter is a broadband filter, a tuned filter or a frequency hopping filter; the third-stage power amplification circuit is formed by cascading a numerical control attenuator and a three-stage gallium nitride power amplifier tube; and the fourth-stage power amplification circuit is formed by cascading a second pi-type attenuator and a last-stage gallium nitride power amplifier tube. The method has the advantages of being high in dynamic range and good in adaptability in a software radio system.

A DCS controller configured to control a digitally controllable scatterer, DCS, to simultaneously serve a subset of multiple receivers, where the DCS includes a plurality of scattering elements arranged on a scattering surface. The DCS controller is configured to determine a single-user codeword for each of the multiple receivers, where the single-user codeword defines a set of scattering elements of the scattering surface of the DCS for the respective receiver and a respective phase shift configuration for each scattering element in the set of scattering elements. The DCS controller is configured to determine a required signal gain for each of the multiple receivers and determine a subset of receivers based on the required signal gains. The DCS controller is configured to determine a subset of scattering elements of the scattering surface for each receiver in the subset of receivers and determine a multiple-user codeword based on the subsets.