21 results about "Automatic frequency control" patented technology

The invention provides a counter, a phase-locked loop, an automatic frequency control system and a control method, and the counter comprises a sampling window generation module which generates a sampling window signal according to a reference clock signal; the counting module is used for counting the number of cycles of the local oscillator clock signal according to the sampling window signal to obtain an initial count value; the edge detector is used for detecting clock edges of the reference clock signal and the local oscillator clock signal and obtaining an addition and subtraction indication signal according to detected edge information; and the counter calibrates the initial count value according to the addition and subtraction indication signal to obtain a counting result. According to the scheme of the invention, an additional edge detection mechanism is added in the counter, and the counting result of the counting module is calibrated, so that the counting precision of the counter is improved, and the accuracy of a frequency control result can be ensured.

The utility model provides a phase-locked loop circuit and an image sensor, and the phase-locked loop circuit comprises a phase frequency detector, a charge pump circuit, a switching circuit, an inductance capacitance voltage-controlled oscillator, an automatic frequency control circuit, and a detection control circuit. The automatic frequency control circuit controls the switching circuit to output a voltage reference signal and output a digital code signal, so that the capacitance in the inductance-capacitance voltage-controlled oscillator is changed, the frequency of an output signal of the phase-locked loop circuit is further changed, after calibration is finished, the phase frequency detector and the charge pump circuit output a changed first voltage signal, and the charge pump circuit outputs a second voltage signal. The capacitance of the inductance capacitance voltage-controlled oscillator and the frequency of an output signal of the phase-locked loop circuit are changed, and the detection control circuit outputs a closing signal to close the automatic frequency control circuit, so that additional circuit power consumption is reduced; digital code signals input by the inductance-capacitance voltage-controlled oscillator are not changed, and disturbance influence is eliminated.

The invention provides an adaptive control method and system for an accelerator klystron, and electronic equipment, and the method comprises the steps: collecting a reverse wave signal in a microwave signal which is generated by an excitation source, is amplified by the klystron, and is inputted to an accelerating tube, and obtaining the current output frequency of the excitation source; performing I / Q orthogonal demodulation on the reverse wave signal to obtain an I / Q signal, and calculating the frequency deviation between the current resonant frequency of the accelerating tube and the current output frequency of the excitation source; and according to the frequency deviation, outputting a frequency control instruction to the excitation source so as to adjust the output frequency of the excitation source, and enabling the current output frequency of the excitation source to track the current resonant frequency of the accelerating tube. By calculating the frequency deviation and directly outputting the control instruction to adjust the output frequency of the excitation source, the technical problems of control object dislocation and response lag existing in a traditional automatic frequency control system are solved.

Provided is a radio resource control system for controlling radio resources for a plurality of aggressor radio devices 12-1 and 12-2 that cause interference in victim radio devices 20-1 and 20-2 of which communication quality should be protected. Included is a radio resource control device 34 that executes a resource inquiry (11) for inquiring regarding available radio resources, as a representative of the plurality of aggressor radio devices 12-1 and 12-2. Included is an AFC server 18 that, in response to the request inquiry, provides the radio resource control device 34 with information of radio resources that can be used by the aggressor radio devices 12-1 and 12-2 within a range in which the amount of interference that the victim radio devices 20-1 and 20-2 are subjected to is no greater than an admissible value, as a response (13). The radio resource control device 34 executes resource centralized control (14) with respect to the plurality of aggressor radio devices 12-1 and 12-2 within a range of the radio resources included in the response.

The invention discloses an ID fan control method applied to a 3500t aluminum oxide suspension roaster, which adopts a control system consisting of a roasting DCS (Distributed Control System), an intelligent Venturi differential pressure module, an intelligent oxygen content control module, a Venturi differential pressure gauge, an oxygen content gauge, a data acquisition unit and a priority selection unit. The intelligent oxygen content control module and the intelligent venturi differential pressure control module are added on the basis of an original roasting DCS (Distributed Control System) to carry out multi-parameter model control, so that the problem that the oxygen content and the venturi differential pressure are both lost is solved, and ID fan multivariable simultaneous automatic frequency control is realized, so that the production stability of an aluminum oxide roasting furnace is improved, and the production cost is reduced. The quality of the final aluminum oxide product is improved, and the purposes of energy conservation and efficiency improvement are achieved.

The utility model proposes a phase-locked loop circuit and an image sensor, the phase-locked loop circuit comprises a phase frequency detector, a charge pump circuit, a switching circuit, an inductance capacitance voltage-controlled oscillator and an automatic frequency control circuit, in a calibration mode, the automatic frequency control circuit controls the switching circuit to output a voltage reference signal, and the inductance capacitance voltage-controlled oscillator outputs the voltage reference signal. The phase-locked loop circuit changes the frequency of an output signal of the phase-locked loop circuit, compares the frequency of the output signal with a clock reference signal, outputs a correspondingly changed digital code value according to a comparison result, and the digital code value changes according to a dichotomy rule, so that the capacitance and frequency of the inductance-capacitance voltage-controlled oscillator are rapidly changed, and the calibration efficiency is improved. After calibration is finished, the phase frequency detector and the charge pump circuit output a variable first voltage signal, and the capacitance of the inductance capacitance voltage-controlled oscillator and the frequency of an output signal of the phase-locked loop circuit are changed.

Techniques for using automatic frequency coordination (AFC for short) in a wireless communication network are described in the present invention. A network controller of a wireless communication network may receive spectrum availability information for operating a plurality of access points (APs) for Wi-Fi communications, the spectrum availability information being obtained by the plurality of APs according to a location of the plurality of APs or a location of the network controller. The network controller further configures a plurality of APs of the wireless communication network to perform Wi-Fi communication based on the spectrum availability information.

The invention belongs to the technical field of integrated circuits, and particularly relates to a frequency source integrating automatic frequency control and a high-linearity voltage-controlled oscillator. The circuit structure of the frequency source comprises a phase frequency detector, a charge pump, a loop filter, a multiband voltage-controlled oscillator, an automatic frequency controller and a programmable fractional frequency divider. A signal of the reference frequency and a signal fed back by the programmable frequency divider are input into the phase frequency detector, and the phase frequency detector compares rising edges of the two signals and outputs a pulse signal to the charge pump; the charge pump converts an input pulse signal into a current signal and charges and discharges the loop filter; the loop filter converts the received current signal into a voltage signal and outputs the voltage signal to the voltage-controlled oscillator; the voltage-controlled oscillator adjusts the frequency of an output signal according to an input voltage signal and a control word of the automatic frequency controller, and feeds back the output signal to the phase frequency detector through the programmable fractional frequency divider to realize loop locking. A capacitor array of the voltage-controlled oscillator is composed of a varactor array and a capacitor tube array, continuous tuning of output frequency is achieved by adjusting varactors, and the automatic frequency controller changes the capacitor tube array of the voltage-controlled oscillator through control words to achieve discrete frequency tuning. Therefore, a wide output frequency range is achieved under the condition of low voltage-controlled oscillator tuning gain, phase noise is optimized at the same time, and automatic locking of frequency in bandwidth can be achieved.

A communication system embeds a trust message into an outbound control channel signal derived from a GPS reference signal associated with trunked communications. The trust message is used as a basis for incrementally expanding the subscriber's automatic frequency control (AFC) range beyond its pre-stored default limits to enable re-tuning a temperature compensated crystal oscillator (TCXO) that has drifted off frequency. Coarse-tuning of the subscriber TCXO is based on a measured frequency error of a control channel outbound transmission determined to fall within the expanded AFC range of the subscriber. Additionally, an inbound signal frequency error may be measured by the base station, and reported to the subscriber to use for fine-tuning the TCXO.

Systems and methods for performing automatic frequency control are provided. Instead of relying on individual frequency tuners for each channel of a multi-channel receiver system, the present subject matter uses a single frequency tuner for receiving each channel of the multi-channel receiver system. A locked demodulator may be designated as a reference demodulator and frequency offset values associated with the reference demodulator may be applied to other demodulators of the multi-channel receiver. These frequency offset values may be used by individual demodulators of each channel for correcting corresponding frequency offsets.

The invention discloses a four-phase ring voltage-controlled oscillator circuit and a calibration method thereof. The circuit comprises a voltage-current conversion module, a current mirror module, an automatic frequency control module and a secondary ring oscillator module. The method comprises the following steps: acquiring an output frequency of a secondary ring oscillator module, and comparing the output frequency with a preset reference frequency to obtain a frequency comparison result; acquiring a numerical control signal generated by an automatic frequency control module based on a preset reference frequency; according to a frequency comparison result, performing logic control on the numerical control signal to generate a control tail current source signal; and the output frequency of the secondary ring oscillator module is calibrated according to the control tail current source signal, and a four-phase differential clock oscillation signal is output. According to the embodiment of the invention, the anti-noise performance and the output precision of the whole phase-locked loop can be improved, the power consumption and the area of circuit design are reduced, and the tolerance of process deviation in different PVT scenes is improved. The circuit can be widely applied to the technical field of integrated circuits.

The invention provides an automatic frequency modulation control method of an air conditioner, the air conditioner and a computer readable storage medium, and the automatic frequency modulation control method of the air conditioner comprises the following steps: when the air conditioner runs, judging whether the running time when the air conditioner does not receive a control instruction reaches a first preset time or not; when it is judged that the operation duration reaches the first preset duration, a first frequency value and a second frequency value are obtained; if the frequency change rate value is smaller than or equal to, the air conditioner is controlled to execute a first preset energy-saving mode; and if the frequency change rate value is larger than the frequency change rate value, abnormal prompt information is sent out, whether a new control instruction is received within the first preset waiting duration or not after the abnormal prompt information is sent out is judged, and if not, the air conditioner is controlled to execute a first preset energy-saving mode. According to the automatic frequency modulation control method for the air conditioner, the situation that the air conditioner runs with high energy consumption due to the abnormal indoor environment is considered, the situation that a user forgets to turn off the air conditioner when going out is also considered, the energy-saving effect is better, and more energy is saved.

In one embodiment, a device determines a physical location of a mobile client of wireless network. The device performs a frequency lookup for the mobile client from an AFC service using the physical location of the mobile client. The device selects a frequency to be used by the mobile client based on the frequency lookup. The device causes the mobile client to use the frequency to communicate with the wireless network.

The invention relates to the technical field of radio frequency communication, and provides a carrier frequency offset compensation method and device, equipment, a medium and a program product, and the method comprises the steps: carrying out the frequency offset compensation of a first subframe of a radio frequency operation according to a normalized frequency offset in a preset duration after a radio frequency module is started if the radio frequency operation is carried out; wherein the normalized frequency offset is obtained by dividing a historical carrier frequency by a historical carrier frequency offset value, the historical carrier frequency offset value is a carrier frequency offset value obtained by carrying out carrier frequency offset measurement on a first subframe within a preset duration after the historical radio frequency module is started, and the historical carrier frequency is the carrier frequency of the historical radio frequency module; the radio frequency parameter of the historical radio frequency module is the same as the radio frequency parameter of the radio frequency module; and performing frequency offset compensation on subframes except the first subframe in the radio frequency operation according to a preset automatic frequency control method. In this way, the first subframe of the radio frequency operation can be effectively compensated, so that the residual carrier frequency offset of the first subframe is significantly reduced.

The invention discloses a high-reliability air suspension oxygenation device and an operation control method thereof.The high-reliability air suspension oxygenation device comprises a cabinet, an air supply air inlet and an oxygenation air outlet are formed in the cabinet, and a frequency converter is installed in the cabinet; the aerator is installed in the cabinet and driven by the frequency converter, and an air inlet of the aerator is located in the cabinet; the sensing monitoring assembly is arranged on the cabinet or the aerator and used for detecting the real-time operation state of the aerator; the man-machine interaction terminal is mounted on the cabinet and is used for a user to set a preset instruction; the controller is mounted in the cabinet and is configured to send an automatic frequency control signal to the frequency converter according to a preset instruction and a real-time operation state; the entity speed regulation knob is arranged on the outer surface of the cabinet and is directly and electrically connected with the frequency converter; the device has the advantages that a redundancy control system can be utilized, the problem that regulation and control cannot be achieved due to electronic element failure in a severe environment is solved, and reliable operation of equipment is ensured.

An unlicensed access point is configured to identify its location and to determine licensed 6 GHz users near that location. The access point periodically generates a beacon frame including a request for location information. Client devices within range of the beacon frame provide their location information to the access point. The access point access point uses the location information gathered from client devices to determine its own location. The access point communicates with a central database containing information on registered licenses within the 6 GHz communication band at the location determined from the client devices. The access point then selects a communication channel within the 6 GHz band that does not conflict with any licensed users in the area, and provides Wi-Fi communication over the selected channel.

The invention provides an adaptive control method and system for a klystron of a medical accelerator, the medical accelerator comprises an excitation source used for generating microwave pulses and an accelerating tube used for accelerating injected electronic pulses, and the method comprises the following steps: acquiring a reflected wave signal at the input end of the accelerating tube; calculating the current resonant frequency of the accelerating tube according to the reflected wave signal; and calculating the frequency deviation between the current output frequency of the excitation source and the current resonant frequency of the accelerating tube, and outputting a frequency tuning instruction to the excitation source based on the frequency deviation so as to adjust the output frequency of the excitation source and enable the output frequency of the excitation source to track the resonant frequency of the accelerating tube. The technical problem of logic failure caused by dislocation of a control object in a traditional automatic frequency control scheme is solved, the output frequency of the excitation source is dynamically adjusted through closed-loop control, efficient injection of microwave energy is ensured, and the system stability and clinical reliability of the system are improved to a great extent.

The invention provides an AFC (Automatic Frequency Control) system applied to a multi-core PLL (Phase Locked Loop), the control system comprises an AFC module arranged in the multi-core PLL, and the multi-core PLL comprises a plurality of capacitor arrays; the AFC module comprises a frequency comparison unit, and the frequency comparison unit is configured to generate an expected sub-band according to all capacitor arrays in the multi-core PLL; generating a target sub-band or a locking failure result according to the expected sub-band and the locking detection result; the expected sub-band is obtained through first sub-band search, and the first sub-band search is carried out based on an AFC dichotomy; a lock detection unit configured to generate a lock detection result according to the desired sub-band; an output control unit configured to transmit the target sub-band or a locking failure result to the multi-core PLL; the multi-core PLL is configured to perform frequency oscillation according to the target sub-band. According to the system, the problem that the existing AFC technology cannot perform frequency control on the multi-core PLL is solved.

A communication system embeds a trust message into an outbound control channel signal derived from a GPS reference signal associated with trunked communications. The trust message is used as a basis for incrementally expanding the subscriber's automatic frequency control (AFC) range beyond its pre-stored default limits to enable re-tuning a temperature compensated crystal oscillator (TCXO) that has drifted off frequency. Coarse-tuning of the subscriber TCXO is based on a measured frequency error of a control channel outbound transmission determined to fall within the expanded AFC range of the subscriber. Additionally, an inbound signal frequency error may be measured by the base station, and reported to the subscriber to use for fine-tuning the TCXO.

The application discloses a communication signal processing method and device, electronic equipment and storage medium, wherein the communication signal processing method comprises the following steps: in the case that a first frequency offset value of a first communication signal is determined to obtain a first frequency offset value, if an automatic frequency control module does not act on the first communication signal, a first frequency point position is obtained by summing the first frequency offset value and a preset frequency point position, and single tone interference in the first communication signal is eliminated according to the first frequency point position; if the automatic frequency control module acts on the first communication signal, a second frequency offset value of a second communication signal is determined to obtain a second frequency offset value, a second frequency point position is obtained by summing the second frequency offset value and the preset frequency point position, and single tone interference in the second communication signal is eliminated according to the second frequency point position. The application solves the technical problem that the automatic control module will affect the position of the single tone interference which has been determined, cause the position of the single tone interference to be inaccurate, affect the effect of single tone interference elimination, and further affect the performance of the communication signal.