A Radio Frequency Channel Control Circuit and Control Method for a Repeater

Abstract

The present disclosure relates to the technical field of repeater radio frequency channel control, and provides a radio frequency channel control circuit and a control method for a repeater. The circuit includes: a radio frequency front-end circuit, whose input end is connected to the output signal processing module of the repeater circuit, and the control end is connected to a processor; it is used to receive a reflected signal and output a transmitted and reflected signal; a feedback module circuit, whose input end is connected to the output end of the radio frequency front-end circuit, and is used to separate the transmitted signal and the reflected signal to obtain a feedback signal, and output the power of the reflected signal in the feedback signal to the processor; a first power meter, which is used to measure the transmitted signal power and then output it to the processor; the processor calculates the voltage standing wave ratio according to the received transmitted signal power and reflected signal power; and executes the radio frequency channel control logic according to the voltage standing wave ratio and the transmitted signal power. The present disclosure can dynamically adjust the standing wave detection period, reduce false alarms and false turn-offs, and achieve automatic channel recovery, thereby reducing the maintenance cost.

Description

Technical Field

[0001] The present disclosure belongs to the technical field of RF channel control of repeaters, and particularly relates to an RF channel control circuit and a control method for a repeater. Background Art

[0002] Repeaters are divided into digital fiber optic repeaters and digital wireless repeaters, and the coupling methods between repeaters and signal sources are divided into two types: wired coupling and wireless coupling. Among them, digital fiber optic repeaters adopt wired coupling, and digital wireless repeaters adopt wireless coupling.

[0003] As shown in Figure 1 a digital fiber optic repeater consists of a radio frequency access unit (Master Unit, MU) and a remote unit (Remote Unit, RU). The radio frequency access unit couples the downlink radio frequency signal of a new radio (NR) signal source into the digital fiber optic repeater system through a wired coupling method, converts it into a digital signal, and then transmits it to the remote unit as an optical signal after optical-electric conversion. At the same time, the digital signal uploaded by the remote unit is converted into an uplink radio frequency signal and transmitted back to the signal source through a wired method. The radio frequency access unit needs to support the functions of remotely monitoring and managing the subordinate remote units and centralized upgrading. The remote unit converts the digital signal sent by the radio frequency access unit into a radio frequency signal to achieve 5G wireless coverage; at the same time, it converts the uplink radio frequency signal received wirelessly into a digital signal and transmits it to the access unit.

[0004] As shown in Figure 2 a digital wireless repeater couples the downlink radio frequency signal of a 5G signal source into the digital wireless repeater through a wireless coupling method, amplifies it with low noise, converts it into a digital signal for digital processing, and then converts it into a radio frequency signal and amplifies it with power to achieve 5G signal wireless coverage; at the same time, the user signal enters the digital wireless repeater system through a wireless reception method, and after digital-to-analog conversion / digital processing / power amplification, it is transmitted back to the signal source through a wireless method.

[0005] Standing wave refers to a distribution state formed along a transmission line by two waves with the same frequency and opposite transmission directions. One of the waves is generally the reflected wave of the other. Wave crests appear at the points where the voltages or currents of the two waves are added, and wave nodes are formed at the points where the voltages or currents of the two waves are subtracted. In terms of waveform, the positions of the wave nodes and wave crests are always unchanged, giving the impression of "standing still", but its instantaneous value changes with time. If the amplitudes of the two waves are equal, the amplitude of the wave node is zero.

[0006] The standing wave ratio, also known as Voltage Standing Wave Ratio (VSWR), is also called VSWR and SWR. It represents the ratio of the voltage amplitude of the wave crest to the voltage amplitude of the wave trough on the transmission line, that is, VSWR = (Vmax / Vmin). It can also be expressed as VSWR = (1 + Γ) / (1 - Γ), where Γ is the reflection coefficient, a parameter describing the degree of reflection of the electrical transmission line, and its value ranges from -1 to 1. When the standing wave ratio is equal to 1, it means that the impedance of the feeder and the antenna is perfectly matched. At this time, all the high-frequency energy is radiated by the antenna, and there is no reflection loss of energy. When the standing wave ratio is infinite, it means total reflection and no energy is radiated out.

[0007] In radio communication, the standing wave ratio is an important parameter to measure the performance of the antenna system. When the standing wave ratio is greater than 1, it means that a part of the radio wave is reflected back and finally turns into heat, causing the feeder to heat up. In practical applications, the standing wave ratio is usually required to be less than 2 to ensure the stability and reliability of the transmission. If the standing wave ratio is too high, it may lead to problems such as signal quality degradation and communication distance shortening. If the energy of the reflected radio wave is too large and a relatively high voltage is generated at the output of the transmitter, it may even damage the transmitter.

[0008] In the in-building distribution system, in order to reduce costs, operators will consider using repeaters to replace the signal source in some low-capacity and low-value scenarios. When the repeater is connected to the in-building distribution system, if there is a fault in the antenna feeder connection or the antenna feeder itself, such as disconnection, virtual connection between the antenna feeder and the repeater, or a fault in the antenna feeder system itself, due to the mismatch of the antenna feeder unit, a relatively high reflected power will be generated, resulting in a very poor standing wave ratio of the system, thus deteriorating the signal transmission effect, decreasing the channel gain of the repeater, causing problems such as the downlink output power of the repeater becoming low and the uplink noise figure increasing. If a part of the signal is reflected to the power amplifier and exceeds the maximum power of the power amplifier, it will cause the power amplifier to burn out, causing fatal damage to the equipment.

[0009] After the repeater receives the signal from the donor base station, the signal is amplified by the power amplifier in the radio frequency hardware and then usually radiates energy through the antenna at the output end. However, when there is no antenna connected to the output end of the repeater or the matching with the antenna is poor, the signal will be reflected back. When the reflected signal passes through the power amplifier, if the transmitted signal power continuously exceeds the power requirement of the power amplifier, it is very easy to burn out the power amplifier, causing fatal damage to the repeater.

[0010] Therefore, in order to protect the repeater equipment, when the repeater is working, it is necessary to detect the VSWR of the repeater and give an indication of whether to turn off the channel according to the detection result.

[0011] The detection process of a repeater is generally as follows: by setting a forward and reverse power detection unit between the duplexer and the antenna port of the repeater, the forward and reverse power detection is usually composed of a forward coupler and a reverse coupler. The forward coupling signal and the reverse coupling signal output from the forward coupler and the reverse coupler are attenuated to a certain value by an attenuator respectively, and the attenuated signal enters the corresponding detector for detection and is output as a voltage signal; the forward voltage and the reverse voltage are amplified by an operational amplifier and then enter the CPU for calculation. The CPU calculates the voltage standing wave ratio based on the forward voltage and the reverse voltage, and then compares the calculated voltage standing wave ratio with the standing wave alarm threshold value set by the system. If the actual voltage standing wave ratio is greater than the standing wave alarm threshold value, an alarm is generated; if it is less than or equal to the standing wave alarm threshold value, it is considered normal.

[0012] Once a standing wave alarm is detected in the repeater, the repeater will directly shut down the channel, such as closing the uplink and downlink, to prevent the RF power amplifier unit output port from being unloaded, resulting in infinite standing waves, thereby protecting the power amplifier module from damage.

[0013] The existing standing wave detection technology has the following problems:

[0014] 1) Currently, when a repeater performs standing wave detection, if an abnormal standing wave is detected, the repeater will shut down the RF channel. When the standing wave returns to normal and the repeater channel needs to be opened, manual intervention is required on site to open the station again. Therefore, the existing solution for opening the station again is inefficient and will increase maintenance costs.

[0015] 2) When the output power of the repeater is low, that is, the useful signal is close to the noise floor, if it is interfered by external signals at this time, the reflected signal measured by the repeater may contain the external interference signal, affecting the accuracy of standing wave detection and increasing the probability of false alarms and false shutdowns. Summary of the invention

[0016] To solve the above problems, the present invention provides a radio frequency channel control circuit and control method for a repeater, which adopts a standing wave detection mechanism based on dynamic adjustment of the detection period of output power, combined with a multiple abnormal trigger shutdown strategy, to achieve automatic channel recovery and effectively reduce the false alarm rate and maintenance cost.

[0017] The following are the technical details of this disclosure:

[0018] A radio frequency channel control circuit of a repeater, characterized by comprising:

[0019] The RF front-end circuit has an input end connected to the output end of the output signal processing module of the repeater circuit, and a control end connected to the output end of the processor of the repeater circuit; after receiving the reflected signal, the transmitted signal and the reflected signal are output simultaneously;

[0020] A feedback module circuit, whose input end is connected to the output end of the RF front-end circuit, is used to separate the transmitted signal and the reflected signal to obtain a feedback signal, measure the power of the reflected signal in the feedback signal and output it to the processor of the repeater circuit;

[0021] A first power meter, whose input end is connected to the output end of the RF front-end circuit, is used to measure the power of the transmitted signal and output it to the processor of the repeater circuit;

[0022] The processor of the repeater circuit is configured to:

[0023] Control the RF front-end circuit to receive the reflected signal irregularly, and calculate the voltage standing wave ratio according to the received transmitted signal power and reflected signal power;

[0024] If the voltage standing wave ratio is greater than the first threshold and the transmitted signal power is greater than the second threshold, cumulatively record the number of standing wave anomalies; if the number of standing wave anomalies reaches the third threshold, trigger the RF channel of the repeater circuit to turn off, reset the number of standing wave anomalies after turning off and record the number of times the RF channel is turned off;

[0025] If the number of times the RF channel is turned off is less than the fourth threshold, wait for the first preset duration and then reopen the channel for detection; if the number of times the RF channel is turned off is not less than the fourth threshold, reset the number of times the RF channel is turned off, open the RF channel after an interval of the second preset duration and continue to detect the standing wave; where the second preset duration is greater than the first preset duration.

[0026] Furthermore,

[0027] The processor of the repeater circuit is further configured to:

[0028] When the voltage standing wave ratio is greater than the first threshold and the transmitted signal power is less than the second threshold, trigger a standing wave alarm;

[0029] If the number of consecutive standing wave anomalies is less than the third threshold, trigger a standing wave alarm each time.

[0030] Furthermore,

[0031] The feedback module circuit includes:

[0032] A coupler, whose input end is connected to the output end of the RF front-end circuit, is used to separate the transmitted signal and the reflected signal output by the RF front-end circuit and then output;

[0033] A first digital step attenuator, whose input end is connected to the output end of the coupler, is used to adjust the power of the transmitted signal and the reflected signal output by the coupler and then output;

[0034] An analog-to-digital conversion circuit, whose input end is connected to the output end of the first digital step attenuator, is used to convert the analog signal into a digital signal and then output a feedback signal;

[0035] A second power meter, whose input end is connected to the output end of the analog-to-digital conversion circuit and whose output end is connected to the input end of the processor, is used to measure the reflected signal power in the feedback signal and then output it to the processor.

[0036] Furthermore,

[0037] The output signal processing module of the repeater circuit includes:

[0038] A digital pre-distortion processing module, whose input end is connected to the output end of the processor, is used to perform DPD operations on the digital signal output by the processor and then output it;

[0039] An analog-to-digital conversion circuit, which is connected in series with the digital pre-distortion processing module, is used to convert the digital signal output by the digital pre-distortion processing module into an analog signal and then output it;

[0040] A second digital step attenuator, whose input end is connected to the output end of the analog-to-digital conversion circuit and whose output end is connected to the input end of the RF front-end circuit, is used to adjust the power of the signal and then output it;

[0041] The processor of the repeater circuit is further configured to:

[0042] When the RF front-end circuit receives a reflected signal, freeze the DPD operation of the digital pre-distortion processing module;

[0043] If the voltage standing wave ratio is normal, control the RF front-end circuit not to receive the reflected signal and start the DPD operation of the digital pre-distortion processing module.

[0044] Furthermore,

[0045] The digital pre-distortion processing module includes:

[0046] A DPD pre-simulation module, which is used to perform pre-simulation on the DPD operation and generate initial pre-distortion parameters;

[0047] A DPD calibration module, whose input end is connected to the output end of the processor and the output end of the DPD pre-simulation module, is used to adjust the pre-distortion parameters and then compensate the signal output by the processor and then output it.

[0048] Furthermore,

[0049] It further includes:

[0050] A data acquisition module, whose input end is connected to the output ends of the first power meter, the feedback module circuit and the DPD calibration module; is used to obtain the transmit signal power, the feedback signal and the DPD calibration data generated by the DPD calibration module and then transmit them to the processor;

[0051] The processor corrects the interference to the transmitted signal power caused by abnormal DPD calibration by comparing the transmitted signal power, the transmitted signal in the feedback signal, and the DPD calibration data, and obtains the corrected transmitted signal power to calculate the voltage standing wave ratio.

[0052] Further,

[0053] The calculation of the voltage standing wave ratio is as follows:

[0054] VSWR =

[0055] where VSWR is the voltage standing wave ratio, is the transmitted signal power, is the reflected signal power.

[0056] Further,

[0057] The processor controls the radio frequency front-end circuit to receive the reflected signal irregularly through the GPIO control interface.

[0058] A control method for a radio frequency channel control circuit of the repeater described above, characterized by including:

[0059] Using a processor to control the radio frequency front-end circuit to receive the reflected signal irregularly, and calculating the voltage standing wave ratio according to the received transmitted signal power and reflected signal power;

[0060] If the voltage standing wave ratio is greater than the first threshold and the transmitted signal power is greater than the second threshold, cumulatively record the number of standing wave anomalies; if the number of standing wave anomalies reaches the third threshold, trigger the radio frequency channel of the repeater circuit to turn off, reset the number of standing wave anomalies after turning off, and record the number of radio frequency channel turn-offs;

[0061] If the number of radio frequency channel turn-offs is less than the fourth threshold, wait for the first preset duration and then reopen the channel for detection; if the number of radio frequency channel turn-offs is not less than the fourth threshold, reset the number of radio frequency channel turn-offs, open the radio frequency channel after an interval of the second preset duration, and continue to detect the standing wave; where the second preset duration is greater than the first preset duration.

[0062] Further,

[0063] The reception time interval for controlling the radio frequency front-end circuit to receive the reflected signal irregularly is as follows:

[0064] If , = ;

[0065] If , = ;

[0066] If , ;

[0067] Wherein, is the set fixed time interval, is the minimum power threshold, is the maximum power threshold; , are adjustment parameters.

[0068] Compared with the prior art, the present disclosure has the following advantages:

[0069] In the radio frequency front-end circuit of the present disclosure circuit, after receiving the reflected signal irregularly, the transmitted signal and the reflected signal are output simultaneously; the first power meter is used to measure the transmitted signal power of the repeater circuit and transmit it to the processor; the feedback module circuit is used to separate the transmitted signal and the reflected signal output by the radio frequency front-end circuit to obtain a feedback signal, measure the reflected signal power in the feedback signal and output it to the processor of the repeater circuit; so that the processor calculates the voltage standing wave ratio according to the transmitted signal power and the reflected signal power, and combines the transmitted signal power to perform radio frequency channel control; wherein:

[0070] The processor controls the radio frequency front-end circuit to perform irregular standing wave measurement, avoiding the blindness and resource waste of fixed-period measurement;

[0071] When the voltage standing wave ratio is greater than the first threshold and the transmitted signal power is greater than the second threshold, the standing wave anomaly count is accumulated and recorded. This judgment method combined with the output power effectively avoids misjudgment caused by external interference. Because when the useful signal is close to the noise floor and is interfered, if only judged according to the voltage standing wave ratio, false alarms and false turn-offs are likely to occur. In this way, when the standing wave is abnormal but the output power is low, only an alarm is triggered and the anomaly count is not accumulated;

[0072] Only when the standing wave anomaly count reaches the third threshold, the radio frequency channel is turned off, preventing frequent turn-off caused by accidental factors; after turn-off, if the radio frequency channel turn-off count is less than the fourth threshold, wait for a certain time and then reopen the channel for detection; if it is not less than the fourth threshold, open the radio frequency channel after a long interval and continue to detect the standing wave. This automatic channel reopening mechanism solves the problems of manual intervention, low efficiency and high maintenance cost in the existing scheme for secondary station opening, realizes the automatic recovery of the channel, greatly improves the maintenance efficiency and reduces the cost.

[0073] Other features and advantages of the present disclosure will be described in the following specification, and, in part, will be obvious from the specification, or will be understood by implementing the present disclosure. The objectives and other advantages of the present disclosure can be achieved and obtained by the structures pointed out in the specification, the claims and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0074] To more clearly illustrate the technical solutions in the embodiments of the present disclosure or the prior art, the following will briefly introduce the accompanying drawings required for the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are some embodiments of the present disclosure. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can also be obtained based on these drawings.

[0075] Figure 1 shows the networking diagram of a digital fiber optic repeater;

[0076] Figure 2 shows the networking diagram of a digital wireless repeater;

[0077] Figure 3 shows the circuit schematic diagram of the present disclosure;

[0078] Figure 4 shows the schematic diagram of the radio frequency channel control logic of the present disclosure. Detailed implementation manners

[0079] To make the objectives, technical solutions, and advantages of the embodiments of the present disclosure clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present disclosure with reference to the accompanying drawings in the embodiments of the present disclosure. Obviously, the described embodiments are some, but not all, of the embodiments of the present disclosure. Based on the embodiments in the present disclosure, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the protection scope of the present disclosure.

[0080] The circuit of the present disclosure is as Figure 3 shown and includes:

[0081] 1) The processor of the repeater circuit;

[0082] 2) The output signal processing module, including:

[0083] The digital predistortion (DPD) processing module, whose input end is connected to the output end of the processor, includes: a DPD pre-simulation module: used to pre-simulate the DPD operation and generate initial predistortion parameters; a digital predistortion calibration module, whose input end is connected to the output ends of the processor and the DPD pre-simulation module, used to adjust the predistortion parameters, and after the signal reaches the best linearization effect, compensate the signal output by the processor and then output.

[0084] The digital-to-analog conversion (DAC) circuit is used to convert the digital signal output by the digital predistortion calibration module into an analog signal;

[0085] A second Digital Step Attenuator (DSA) is used to adjust the power of the above-mentioned analog signal and then output it.

[0086] 3) A Radio Frequency Front End (AFE) circuit, whose input end is connected to the output end of the output signal processing module of the repeater circuit, and whose control end is connected to the output end of the processor of the repeater circuit; includes:

[0087] A Power Amplifier (PA) is used to amplify and output the signal after the DSA adjusts the power.

[0088] A switch module and a filter module, whose input end is connected to the output end of the power amplifier PA.

[0089] Among them, the switch module is used to realize the dynamic switching of the signal path or working mode (such as standing wave detection and normal operation);

[0090] The filter module is used to perform frequency selection on the radio frequency signal.

[0091] The radio frequency front end circuit is used to receive the reflected signal and then output the transmitted signal and the reflected signal simultaneously.

[0092] 4) An antenna ANT is used to broadcast the signal output by the radio frequency front end circuit.

[0093] 5) A first power meter, whose input end is connected to the output end of the radio frequency front end circuit, is used to measure the transmitted signal power and then output it to the processor of the repeater circuit;

[0094] 6) A feedback module circuit, whose input end is connected to the output end of the radio frequency front end circuit, includes:

[0095] A coupler: arranged at the output end of the power amplifier, is used to separate and output the transmitted signal and the reflected signal output by the radio frequency front end circuit;

[0096] A first Digital Step Attenuator DSA, whose input end is connected to the output end of the coupler, is used to adjust the power of the transmitted signal and the reflected signal output by the coupler and then output them;

[0097] An analog-to-digital conversion circuit, whose input end is connected to the output end of the first Digital Step Attenuator DSA, is used to convert the analog signal into a digital signal and then output a feedback signal;

[0098] A second power meter, whose input end is connected to the output end of the analog-to-digital conversion circuit, and whose output end is connected to the input end of the processor, is used to measure the reflected signal power in the feedback signal and then output it to the processor.

[0099] 7) Data acquisition module, whose input end is connected to the output ends of the first power meter, the feedback module circuit and the DPD calibration module; it is used to obtain the transmitted signal power, the feedback signal and the DPD calibration data generated by the DPD calibration module and then transmit them to the processor;

[0100] The processor corrects the interference to the transmitted signal power caused by abnormal DPD calibration by comparing the transmitted signal power, the transmitted signal in the feedback signal and the DPD calibration data, and obtains the corrected transmitted signal power to calculate the voltage standing wave ratio, so as to improve the accuracy of standing wave calculation.

[0101] Specifically, the processor is configured with working mode coordination control (freeze DPD operation → switch to detection mode → resume DPD operation), including:

[0102] If the voltage standing wave ratio VSWR is normal during the standing wave detection, start the digital predistortion (DPD) processing module to work normally. At this time, the radio frequency front-end circuit AFE becomes the normal DPD working mode (does not receive reflected signals);

[0103] When the processor actively triggers the VSWR detection, temporarily freeze the DPD operation, and switch the GPIO interface to the VSWR working mode (realized by the processor sending a control signal to the radio frequency front-end circuit); after completing the VSWR measurement, switch the GPIO back to the normal mode and resume the DPD operation; the processor actively reads the VSWR result and status.

[0104] Function: By measuring the VSWR irregularly, it can not only ensure the accuracy of VSWR measurement, but also ensure the normal operation of the DPD function of the repeater, and at the same time avoid the power consumption increase caused by frequent detection.

[0105] Specifically, the processor also dynamically adjusts the detection period T according to the output power:

[0106] In this disclosure, the AFE (radio frequency front-end circuit) irregularly performs VSWR detection on all transmitted (TX) signals. Among them, the detection interval T is related to the repeater channel power P, and T meets the following formula requirements:

[0107] The detection interval T is:

[0108] If , = ;

[0109] If , = ;

[0110] If , ;

[0111] Among them, is the set fixed time interval, is the minimum power threshold, is the maximum power threshold; , are adjustment parameters.

[0112] Specifically:

[0113]

[0114] Among them, T is the detection interval, is the set period value, , are adjustment parameters, is the transmit signal power.

[0115] Specifically, the calculation of the voltage standing wave ratio of the present disclosure is:

[0116] VSWR =

[0117] Among them, VSWR is the voltage standing wave ratio, is the transmit signal power, is the reflected signal power.

[0118] 2. The operation logic of the circuit of the present disclosure for automatically turning on & off the RF channel is as Figure 4 shown, including:

[0119] Periodically detect the standing wave. When the standing wave is detected to be abnormal, the repeater processor determines whether there is a standing wave abnormality based on the transmit power. When multiple rounds of detection all show a standing wave abnormality, it proves that the standing wave detection is correct, and at the same time, the remote channel is closed; after the channel shutdown is triggered, when the number of shutdowns is less than the specified number, after waiting for a certain time, the channel is automatically opened and the standing wave is detected. The waiting time each time is related to the number of shutdowns. If multiple rounds of detection all trigger the channel shutdown, the repeater will perform a long-term channel shutdown until the standing wave returns to normal, and then start the next round of standing wave detection.

[0120] The technical details are specifically as follows:

[0121] 1) The repeater starts to perform standing wave detection, and the standing wave detection period T is determined according to the transmit signal power P of the repeater;

[0122] 2) When the standing wave value is greater than 3.5 and the transmit signal power is less than 27 dBm, trigger a standing wave alarm;

[0123] 3) When the standing wave value is greater than 3.5 and the transmit signal power is greater than 27 dBm, record the number of standing wave abnormalities; when the number of consecutive standing wave abnormalities is less than M times, each time a standing wave alarm is triggered.

[0124] 4) When the number of standing wave anomalies is greater than or equal to M times, trigger the channel to shut down. After the channel shutdown is triggered, the number of standing wave anomalies is cleared, and the shutdown count is recorded.

[0125] 5) When the shutdown count is less than N times, wait for m minutes and then reopen the channel to perform standing wave detection.

[0126] 6) After the cumulative trigger reaches N times, trigger an alarm for the channel to shut down, clear the shutdown count. At the same time, the device will automatically open the channel after an interval of H hours, and then continue to perform standing wave detection normally.

[0127] For the nth detection, m meets the requirements of the following formula:

[0128] m =

[0129] where M, N, H, and t are determined according to the requirements of network indicators, is the coefficient for controlling the waiting time.

[0130] In summary, the present disclosure scheme proposes a new method for standing wave detection and automatic channel switching of a repeater. The repeater performs multiple polling detections on the standing wave. Each detection period is related to the transmission signal power of the repeater. When multiple detections are all abnormal and each output power is greater than the threshold power, the radio frequency channel will be closed. After the channel is shut down for a certain period of time, it will be automatically opened (the specific time is related to the shutdown count). When the channel shutdown is continuously triggered multiple times, it will wait for a longer time before automatically opening the channel, and then continue the next round of standing wave detection.

[0131] The present disclosure scheme has the following innovations:

[0132] 1) The existing repeater detection scheme adopts a fixed-time standing wave detection scheme, which does not consider the influence of the repeater output power on the detection interval duration. The present disclosure optimizes the detection interval duration based on the repeater output power, performs normal periodic detection on the standing wave within a reasonable range of output power, and increases the detection frequency when the output power is too large or too small, so as to make the detection period more reasonable.

[0133] 2) When the repeater detects standing wave anomalies, it usually directly closes the channel without considering the situation of false alarms and false shutdowns. The present disclosure optimizes the detection scheme. The repeater will only close the remote channel when it continuously detects standing wave anomalies multiple times, reducing the probability of false alarms and false shutdowns.

[0134] 3) After the repeater channel is closed, the channel will only be opened when the standing wave returns to normal, and manual intervention is required on site during the channel opening process. By optimizing the shutdown duration, the present disclosure makes the shutdown duration more reasonable. After reaching the shutdown time, the repeater will automatically open the channel without manual intervention, reducing the maintenance cost.

[0135] Based on the circuit of the present disclosure, the present disclosure also provides a control method for the above circuit, which includes:

[0136] Using a processor to control the RF front-end circuit to receive reflected signals irregularly;

[0137] Calculating the voltage standing wave ratio according to the received transmit signal power and reflected signal power; and when the RF front-end circuit receives a reflected signal, freezing the DPD operation of the DPD processing module;

[0138] If the voltage standing wave ratio is normal, controlling the RF front-end circuit not to receive reflected signals and starting the DPD operation of the DPD processing module;

[0139] If the voltage standing wave ratio is greater than the first threshold and the transmit signal power is greater than the second threshold, cumulatively record the number of standing wave anomalies; if the number of standing wave anomalies reaches the third threshold, trigger the RF channel shutdown of the repeater circuit, reset the number of standing wave anomalies after shutdown, and record the number of RF channel shutdowns;

[0140] If the number of RF channel shutdowns is less than the fourth threshold, wait for m minutes and then reopen the channel for detection; if the number of RF channel shutdowns is not less than the fourth threshold, reset the number of RF channel shutdowns, open the RF channel after an interval of H hours, and continue to detect the standing wave.

[0141] Although the present disclosure has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present disclosure.

Claims

1. A radio frequency channel control circuit for a repeater, characterized in that, Comprising: A radio frequency front-end circuit, whose input end is connected to the output end of the output signal processing module of the repeater circuit, and whose control end is connected to the output end of the processor of the repeater circuit; After receiving the reflected signal, it outputs the transmitted signal and the reflected signal simultaneously; A feedback module circuit, whose input end is connected to the output end of the radio frequency front-end circuit, and is used to separate the transmitted signal and the reflected signal to obtain a feedback signal, measure the power of the reflected signal in the feedback signal and output it to the processor of the repeater circuit; A first power meter, whose input end is connected to the output end of the radio frequency front-end circuit, and is used to measure the transmitted signal power and output it to the processor of the repeater circuit; The processor of the repeater circuit is configured to: Control the radio frequency front-end circuit to receive the reflected signal irregularly, and calculate the voltage standing wave ratio according to the received transmitted signal power and reflected signal power; If the voltage standing wave ratio is greater than the first threshold and the transmitted signal power is greater than the second threshold, cumulatively record the number of standing wave anomalies; If the number of standing wave anomalies reaches the third threshold, trigger the shutdown of the radio frequency channel of the repeater circuit, reset the number of standing wave anomalies after shutdown and record the number of radio frequency channel shutdowns; If the number of radio frequency channel shutdowns is less than the fourth threshold, wait for the first preset duration and then reopen the channel for detection; if the number of radio frequency channel shutdowns is not less than the fourth threshold, reset the number of radio frequency channel shutdowns, open the radio frequency channel after an interval of the second preset duration and continue to detect the standing wave; wherein, the second preset duration is greater than the first preset duration; The output signal processing module of the repeater circuit includes: A digital pre-distortion processing module, whose input end is connected to the output end of the processor, and is used to perform DPD operation on the digital signal output by the processor and then output; A digital-to-analog conversion circuit, connected in series with the digital pre-distortion processing module, and is used to convert the digital signal output by the digital pre-distortion processing module into an analog signal and then output; A second digital step attenuator, whose input end is connected to the output end of the digital-to-analog conversion circuit, and whose output end is connected to the input end of the radio frequency front-end circuit, and is used to adjust the power of the signal and then output; The processor of the repeater circuit is further configured to: When the radio frequency front-end circuit receives the reflected signal, freeze the DPD operation of the digital pre-distortion processing module; If the voltage standing wave ratio is normal, control the radio frequency front-end circuit not to receive the reflected signal, and start the DPD operation of the digital pre-distortion processing module; The digital pre-distortion processing module includes: A DPD pre-simulation module, used to perform pre-simulation on the DPD operation and generate initial pre-distortion parameters; A DPD calibration module, whose input end is connected to the output end of the processor and the output end of the DPD pre-simulation module, and is used to adjust the pre-distortion parameters and then compensate the signal output by the processor and then output; It further includes: A data acquisition module, whose input end is connected to the output ends of the first power meter, the feedback module circuit and the DPD calibration module; and is used to obtain the transmitted signal power, the feedback signal and the DPD calibration data generated by the DPD calibration module and then transmit them to the processor; The processor corrects the interference to the transmitted signal power caused by the DPD calibration anomaly by comparing the transmitted signal power, the transmitted signal in the feedback signal and the DPD calibration data, and obtains the corrected transmitted signal power to calculate the voltage standing wave ratio.

2. The radio frequency channel control circuit of a repeater according to claim 1, characterized in that The processor of the repeater circuit is further configured to: When the voltage standing wave ratio is greater than the first threshold and the transmitted signal power is less than the second threshold, trigger a standing wave alarm; If the number of consecutive standing wave anomalies is less than the third threshold, trigger a standing wave alarm each time.

3. The RF channel control circuit of a repeater according to claim 1, characterized in that, The feedback module circuit includes: A coupler, whose input end is connected to the output end of the RF front-end circuit, and is used to separate and output the transmitted signal and the reflected signal output by the RF front-end circuit; A first digital step attenuator, whose input end is connected to the output end of the coupler, and is used to adjust the power of the transmitted signal and the reflected signal output by the coupler and then output; An analog-to-digital conversion circuit, whose input end is connected to the output end of the first digital step attenuator, and is used to convert the analog signal into a digital signal and then output a feedback signal; A second power meter, whose input end is connected to the output end of the analog-to-digital conversion circuit, and the output end is connected to the input end of the processor, and is used to measure the reflected signal power in the feedback signal and then output it to the processor.

4. The radio frequency channel control circuit of a repeater according to claim 1, characterized in that, The calculation of the voltage standing wave ratio is: VSWR= Among them, VSWR is the voltage standing wave ratio, is the transmitted signal power, is the reflected signal power.

5. The RF channel control circuit of a repeater according to claim 1, characterized in that The processor controls the RF front-end circuit to receive the reflected signal irregularly through the GPIO control interface.

6. A control method for a radio frequency channel control circuit of the repeater according to claim 1, characterized in that, It includes: Using the processor to control the RF front-end circuit to receive the reflected signal irregularly, and calculating the voltage standing wave ratio according to the received transmitted signal power and reflected signal power; If the voltage standing wave ratio is greater than the first threshold and the transmitted signal power is greater than the second threshold, cumulatively record the number of standing wave anomalies; If the number of standing wave anomalies reaches the third threshold, trigger the shutdown of the RF channel of the repeater circuit, reset the number of standing wave anomalies after shutdown, and record the number of RF channel shutdowns; If the number of RF channel shutdowns is less than the fourth threshold, wait for the first preset duration and then reopen the channel for detection; if the number of RF channel shutdowns is not less than the fourth threshold, reset the number of RF channel shutdowns, open the RF channel after an interval of the second preset duration and continue to detect the standing wave; where the second preset duration is greater than the first preset duration.

7. The control method according to claim 6, wherein The receiving time interval for the described control radio frequency front-end circuit to receive reflected signals irregularly is as follows: If , = ; If , = ; If , = ; Among them, is the set fixed time interval, is the minimum power threshold, is the maximum power threshold; , are adjustment parameters.

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