WO2021072711A1

WO2021072711A1 - Channel detection method and apparatus

Info

Publication number: WO2021072711A1
Application number: PCT/CN2019/111739
Authority: WO
Inventors: 王宇; 王焱; 赵丹
Original assignee: 深圳市大疆创新科技有限公司
Priority date: 2019-10-17
Filing date: 2019-10-17
Publication date: 2021-04-22
Also published as: CN111713129A

Abstract

A channel detection method and apparatus. The method comprises: performing zero-crossing detection on a received radio frequency signal to obtain zero-crossing data of the radio frequency signal; performing linearity detection on the zero-crossing data of the radio frequency signal to obtain linearity feature data; and if the linearity feature data satisfies a determination condition for a radar signal, determining that a frequency band corresponding to the radio frequency signal is occupied by a radar. Therefore, the frequency of a radar signal can be accurately measured, and the interference resistance is high, such that a wireless communication device avoids a radar channel during the use of a DFS frequency band, in order to ensure the normal transmission of data.

Description

Channel detection method and device

Technical field

The embodiments of the present application relate to the field of communication technologies, and in particular, to a channel detection method and device.

Background technique

With the development of wireless communication technology, the number of devices in the 2.4GHz and 5.8GHz frequency bands has grown rapidly, making this frequency band increasingly crowded and overwhelmed, and interference between devices has become more and more serious.

At present, the expansion of the working channel frequency band can be achieved by using the dynamic frequency selection (Dynamic Frequency Selection, DFS) frequency band.

However, 5.25～5.35GHz and 5.47～5.725GHz are the working frequency bands of the global radar system. When wireless communication equipment uses the DFS frequency band, it is easy to cause interference to the radar system, causing conflicts between the working channel and the radar channel, and affecting the normal transmission of data.

Summary of the invention

The embodiments of the present application provide a channel detection method and device, which can accurately detect the frequency of radar signals and have strong anti-interference ability, so that when wireless communication equipment uses the DFS frequency band, it can avoid radar channels and ensure data integrity. Normal transmission.

In the first aspect, an embodiment of the present application provides a channel detection method, and the method includes:

Performing zero-crossing detection on the received radio frequency signal to obtain zero-crossing data of the radio frequency signal;

Performing linearity detection on the zero-crossing data of the radio frequency signal to obtain linearity characteristic data;

If the linearity characteristic data meets the discrimination condition of the radar signal, it is determined that the frequency band corresponding to the radio frequency signal is occupied by the radar.

In a second aspect, an embodiment of the present application provides a channel detection device. The device includes a memory and a processor. The memory is used to store program instructions. The processor is used to execute the program instructions stored in the memory. When the program instructions are executed, the processor is used to:

In a third aspect, an embodiment of the present application provides a readable storage medium on which a computer program is stored; when the computer program is executed, it implements the channel described in the embodiment of the present application in the first aspect. Detection method.

In a fourth aspect, an embodiment of the present application provides a program product, the program product includes a computer program, the computer program is stored in a readable storage medium, and at least one processor of a ground information processing device or an unmanned vehicle can be downloaded from The readable storage medium reads the computer program, and the at least one processor executes the computer program to cause the ground information processing apparatus to implement the channel detection method according to the embodiment of the present application in the first aspect.

In a fifth aspect, an embodiment of the present application also provides an unmanned aerial vehicle that applies the channel detection method described in the first aspect. When the frequency band corresponding to the radio frequency signal is occupied by radar, the frequency band occupied by the radar is disabled as Communication channel.

In a sixth aspect, an embodiment of the present application also provides a remote control for a movable platform, which applies the channel detection method described in the first aspect to communicate with a drone. When the frequency band corresponding to the radio frequency signal is occupied by radar, Disable the frequency band occupied by the radar as a communication channel.

The channel detection method and device provided in the embodiments of the present application obtain the zero-crossing data of the radio frequency signal by performing zero-crossing detection on the received radio frequency signal; and perform linearity detection on the zero-crossing data of the radio frequency signal to obtain linearity. Degree characteristic data; if the linearity characteristic data satisfies the discrimination condition of the radar signal, it is determined that the frequency band corresponding to the radio frequency signal is occupied by the radar. Therefore, the frequency of the radar signal can be accurately detected, and the anti-interference ability is strong, so that when the wireless communication device uses the DFS frequency band, it can avoid the radar channel and ensure the normal transmission of data.

Description of the drawings

In order to more clearly describe the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the drawings in the following description These are some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative work.

FIG. 1 is a schematic diagram of an application scenario of an embodiment of this application;

FIG. 2 is a flowchart of a channel detection method provided by an embodiment of the application;

FIG. 3 is a flowchart of a channel detection method provided by another embodiment of this application;

FIG. 4 is a functional block diagram of a channel detection method provided by an embodiment of the application;

FIG. 5 is a logic circuit diagram of a channel detection method provided by an embodiment of this application;

FIG. 6 is a flowchart of a channel detection method provided by another embodiment of this application;

FIG. 7 is a schematic structural diagram of a channel detection device provided by an embodiment of the application.

Detailed ways

In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments It is a part of the embodiments of the present application, but not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by a person of ordinary skill in the art without creative work shall fall within the protection scope of this application.

It should be noted that when a component is referred to as being "fixed to" another component, it can be directly on the other component or a central component may also exist. When a component is considered to be "connected" to another component, it can be directly connected to the other component or there may be a centered component at the same time.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field of this application. The terminology used in the specification of the application herein is only for the purpose of describing specific embodiments, and is not intended to limit the application. The term "and/or" as used herein includes any and all combinations of one or more related listed items.

Hereinafter, some embodiments of the present application will be described in detail with reference to the accompanying drawings. In the case of no conflict, the following embodiments and features in the embodiments can be combined with each other.

Fig. 1 is a schematic diagram of an application scenario of an embodiment of the application. In this embodiment, an unmanned aerial vehicle is taken as an example for description.

The unmanned aerial system 100 may include a drone 110, a display device 130, and a control terminal 140. Among them, the UAV 110 may include a power system 150, a flight control system 160, a frame, and a pan/tilt 120 carried on the frame. The drone 110 can wirelessly communicate with the control terminal 140 and the display device 130. The frame may include a fuselage and a tripod (also called a landing gear). The fuselage may include a center frame and one or more arms connected to the center frame, and the one or more arms extend radially from the center frame. The tripod is connected with the fuselage, and is used for supporting the UAV 110 when it is landed. The power system 150 may include one or more electronic governors (referred to as ESCs) 151, one or more propellers 153, and one or more motors 152 corresponding to the one or more propellers 153, wherein the motors 152 are connected to Between the electronic governor 151 and the propeller 153, the motor 152 and the propeller 153 are arranged on the arm of the UAV 110; the electronic governor 151 is used to receive the driving signal generated by the flight control system 160 and provide driving according to the driving signal Current is supplied to the motor 152 to control the speed of the motor 152. The motor 152 is used to drive the propeller to rotate, so as to provide power for the flight of the drone 110, and the power enables the drone 110 to achieve one or more degrees of freedom of movement. The flight control system 160 may include a flight controller 161 and a sensing system 162. The sensing system 162 is used to measure the attitude information of the drone, that is, the position information and state information of the drone 110 in space, such as three-dimensional position, three-dimensional angle, three-dimensional velocity, three-dimensional acceleration, and three-dimensional angular velocity. The flight controller 161 is used to control the flight of the drone 110, for example, it can control the flight of the drone 110 according to the attitude information measured by the sensor system 162. The pan/tilt head 120 may include a motor 122. The pan/tilt is used to carry the camera 123. The flight controller 161 can control the movement of the pan-tilt 120 through the motor 122. The photographing device 123 can communicate with the flight controller and take pictures under the control of the flight controller. The display device 130 is located on the ground end of the unmanned aerial system 100, can communicate with the drone 110 in a wireless manner, and can be used to display the attitude information of the drone 110. The control terminal 140 is located on the ground end of the unmanned aerial system 100, and can communicate with the drone 110 in a wireless manner for remote control of the drone 110.

Since the 2.4GHz and 5.8GHz frequency bands are very crowded and the interference between devices is serious, therefore, in this embodiment, when the drone 110 communicates with the control terminal 140 and the display device 130 wirelessly, dynamic frequency selection (Dynamic Frequency Selection) is adopted. , DFS) frequency band to achieve the expansion of the working channel frequency band. Before using the DFS frequency band, it is necessary to perform zero-crossing detection on the radio frequency signal received by the drone to obtain the zero-crossing data of the radio frequency signal; then perform linearity detection on the zero-crossing data of the radio frequency signal to obtain linearity characteristic data; The linearity characteristic data satisfies the discrimination condition of the radar signal, and the channel corresponding to the radio frequency signal is determined to be the radar channel. Finally, the frequency band corresponding to the radar channel is set as a forbidden frequency band, and the non-radar channel is used for data transmission between the UAV 110 and the control terminal 140 and the display device 130. This embodiment can effectively improve the utilization rate of frequency band resources, so that when the wireless communication device uses the DFS frequency band, it can avoid radar channels and ensure the normal transmission of data.

Fig. 2 is a flowchart of a channel detection method provided by an embodiment of this application. As shown in Fig. 2, the method of this embodiment may include:

S201: Perform zero-crossing detection on the received radio frequency signal to obtain zero-crossing data of the radio frequency signal.

In this embodiment, the radio frequency signal received by the communication device may be a fixed-frequency sinusoidal signal or a Chirp signal (typical non-stationary signal, such as a chirp signal). Under normal circumstances, radio frequency signals can be represented by amplitude I and phase Q on polar coordinates; therefore, radio frequency signals can also be called I/Q signals. By performing zero-crossing detection on the I/Q signal, the zero-crossing data of the radio frequency signal can be obtained. Among them, the zero-crossing data refers to the number of times the signal passes through the zero point. For example, when a signal changes from a positive signal to a negative signal, or from a negative signal to a positive signal, it is considered that a zero point has passed. The frequency of the signal can be obtained by counting the number of zero crossings of the signal within the preset time period. Therefore, the zero-crossing data can be used to characterize the frequency characteristics of the signal.

In an alternative embodiment, the radio frequency signal is sampled to obtain sample data; the sample data is divided into groups to obtain multiple packet data; wherein, each packet data contains the same number of sampling points; The packet data undergoes zero-crossing detection to obtain zero-crossing data; the zero-crossing data is related to the frequency of the radio frequency signal.

In this embodiment, the signals of adjacent sampling points in the packet data are sequentially compared; if the sign bits of the signals of the adjacent sampling points are different, the number of zero-crossings is automatically increased by 1. Among them, the zero-crossing data is the total of the packet data passing through the zero point. frequency.

Specifically, in order to obtain the linearity of the zero-crossing data more accurately, the number of sampling points in each group can be set to 128 or 256. Setting 128 or 256 sampling points as a group is to match the length of the register. In practical applications, the sampling points can be grouped according to any number.

In another alternative embodiment, the received radio frequency signal is divided into two channels to obtain the first channel signal and the second channel signal; wherein, the first channel signal and the second channel signal are the same; The signal performs zero-crossing detection to obtain the zero-crossing data of the first signal; modulates the second signal to obtain the modulated signal; performs zero-crossing detection on the modulated signal to obtain the zero-crossing data of the second signal.

Optionally, the phase angle of the second signal can be modulated to obtain a modulated signal. For example, a 90-degree phase rotation process can be performed on the radio frequency signal, so that the phase of the signal can be changed. Specifically, Table 1 shows the input data and the output data after modulation.

Table 1

In Table 1, a fixed 90-degree phase rotation is used, so the RF signal can be converted into an input I/Q conversion method. Among them, MOD (idx, 4) means that the sampled points are taken modulo 4.

It should be noted that the modulation angle can be any angle that is non-zero. This embodiment takes 90 degrees as an example for detailed description. The modulation methods for other angles are similar and will not be repeated.

In this embodiment, since the zero-crossing data of the signal is easily interfered by noise, the radio frequency signal can be divided into two channels, one of which is modulated, and then the two channels of data are respectively subjected to zero-crossing detection to obtain two channels of signals The zero-crossing data. By performing subsequent zero-crossing detection on the two-way zero-crossing data, the linearity detection result can be made more accurate.

S202: Perform linearity detection on the zero-crossing data of the radio frequency signal to obtain linearity characteristic data.

In this embodiment, after the zero-crossing data of the radio frequency signal is acquired, the linearity of the fitted straight line corresponding to the zero-crossing data can be detected to obtain linearity characteristic data.

In an optional implementation manner, linearity detection can be performed on the zero-crossing data of the first signal and the zero-crossing data of the second signal, respectively, to obtain the linearity characteristic data of the first signal and the second signal Characteristic data of linearity.

Exemplarily, a fitting operation may be performed on the zero-crossing data to obtain characteristic parameters of the fitted straight line; the characteristic parameters of the fitted straight line constitute linearity characteristic data.

In this embodiment, the curve fitting method of the least square method may be used to obtain the characteristic parameters of the fitted straight line corresponding to the zero-crossing data, or the characteristic parameters of the fitted straight line may be judged by the linearity of other scattered points.

Specifically, the least square method is taken as an example for detailed description. For straight-line fitting of equal precision observations, you can use

The value of is obtained from the smallest value; among them, x _i represents the i-th input data, and _yi represents the i-th observation data; a and b are the two parameters of the fitted straight line, and N represents the number of sampling points grouping. The estimated values of the parameters of the fitted straight line can be obtained by derivation

with

Let var=mean(|y _i -a-bx _i |), where mean() represents the average value; var represents the characteristic parameter of the fitted straight line, which constitutes the linearity characteristic data.

Exemplarily, the characteristic parameters of the fitted straight line corresponding to the zero-crossing data can be determined by looking up the table; the characteristic parameters of the fitted straight line constitute linearity characteristic data.

In this embodiment, when the mapping table between the zero-crossing data and the characteristic parameters corresponding to the fitted straight line is established in advance, the characteristic parameters of the fitted straight line corresponding to the zero-crossing data can be directly determined by looking up the table.

S203: If the linearity characteristic data meets the discrimination condition of the radar signal, it is determined that the frequency band corresponding to the radio frequency signal is occupied by the radar.

In this embodiment, the judgment condition of the radar signal includes: the slope of the fitting straight line corresponding to the linearity characteristic data is smaller than the threshold of the radar signal. Specifically, the slope of the corresponding fitted straight line can be obtained according to the linearity characteristic data. If the slope is less than the threshold of the radar signal, it is determined that the frequency band corresponding to the radio frequency signal is occupied by the radar.

In an optional implementation, if the linearity characteristic data of the first signal and/or the linearity characteristic data of the second signal meet the criteria for the radar signal, it is determined that the frequency band corresponding to the radio frequency signal is occupied by the radar .

In this embodiment, the zero-crossing data of the radio frequency signal is obtained by performing zero-crossing detection on the received radio frequency signal; linearity detection is performed on the zero-crossing data of the radio frequency signal to obtain linearity characteristic data; if the linearity characteristic data satisfies the radar signal According to the judgment condition, it is determined that the frequency band corresponding to the radio frequency signal is occupied by the radar. Therefore, the frequency of the radar signal can be accurately detected, and the anti-interference ability is strong, so that when the wireless communication device uses the DFS frequency band, it can avoid the radar channel and ensure the normal transmission of data.

FIG. 3 is a flowchart of a channel detection method provided by another embodiment of this application. As shown in FIG. 3, the method in this embodiment may include:

S301. Determine a time range for turning on radio frequency signal reception, and receive radio frequency signals within the time range.

In this embodiment, the detection interval of the radio frequency signal can be set. For example, delay start processing is performed on the received radio frequency signal, and the delay time can be flexibly set according to actual needs. The function of delayed start is mainly to obtain a better zero-crossing detection interval and eliminate some radio frequency signals with strong interference signals.

S302: Perform zero-crossing detection on the received radio frequency signal to obtain zero-crossing data of the radio frequency signal.

S303: Perform linearity detection on the zero-crossing data of the radio frequency signal to obtain linearity characteristic data.

S304. If the linearity characteristic data meets the discrimination condition of the radar signal, it is determined that the frequency band corresponding to the radio frequency signal is occupied by the radar.

For the specific implementation process and implementation principle of step S302 to step S304 in this embodiment, refer to the related description of step S201 to step S203 shown in FIG. 2, and will not be repeated here.

Fig. 4 is a functional block diagram of the channel detection method provided by an embodiment of the application. As shown in Fig. 4, the input I/Q signal (i.e., radio frequency signal) is divided into two channels after the start-up delay, and the signal processing process of one channel is: Perform I/Q signal zero-crossing judgment, I/Q road zero-crossing data screening, zero-crossing data linearity detection, and output the linearity characteristic data of the first branch. The processing process of the other signal is: sequential fixed frequency offset processing (such as phase modulation), I/Q signal zero-crossing judgment, I/Q zero-crossing data screening, zero-crossing data linearity detection, and outputting the linearity of the second branch Degree characteristic data. Then, it is judged whether the linearity characteristic data of the first branch and the linearity characteristic data of the second branch satisfy the judgment condition of the radar signal. If the linearity characteristic data of the first branch and the linearity characteristic data of the second branch satisfy the discrimination condition of the radar signal, it is determined that the frequency band corresponding to the radio frequency signal is occupied by the radar.

Exemplarily, the slope of the fitted straight line corresponding to the linearity characteristic data is acquired, and if the slope is less than the threshold value of the radar signal, it is a radar signal. Specifically, the threshold of the Chirp signal is used as the judgment condition of the radar signal. If the slope is less than the threshold of the Chirp signal, it is an ordinary radar signal; if the slope is within the threshold of the Chirp signal, the radio frequency signal is the Chirp signal.

Fig. 5 is a logic circuit diagram of a channel detection method provided by an embodiment of the application. As shown in Fig. 5, the input signal s(12, 0) is divided into the first branch I/Q signal after a preset delay, and the first branch I/Q signal, and the first branch I/Q signal. Two-branch I/Q signal; the first branch I signal obtains the current sampling point signal u(1,0). After the sampling point signal is delayed, it is XORed with the next sampling point signal. If the two sampling signals If they are the same, output 0; if they are not the same, output 1, and then accumulate the output XOR results, and output the zero-crossing times Y(i). The Q signal of the first branch obtains the current sampling point signal u(1,0). After the sampling point signal is delayed, it performs an exclusive OR operation with the next sampling point signal. If the two sampling signals are the same, it outputs 0; if not the same Then output 1, and then accumulate the output XOR results, and output the number of zero crossings Y(i). Further, the energy of the first branch I signal and the first branch Q signal are compared by a comparator, and the output result of the branch signal with the larger energy is selected as the final result.

The second branch I/Q signal is frequency modulated (increasing the signal frequency by rotating the phase), and then the second branch I signal obtains the current sampling point signal u(1,0). After the sampling point signal is delayed Perform XOR operation with the next sampling point signal. If the two sampled signals are the same, output 0; if they are not the same, output 1. Then, the output XOR results are accumulated, and the zero crossing times Y(i) are output. The Q signal of the second branch obtains the current sampling point signal u(1,0). After the sampling point signal is delayed, it performs an exclusive OR operation with the next sampling point signal. If the two sampling signals are the same, it outputs 0; if not the same Then output 1, and then accumulate the output XOR results, and output the number of zero crossings Y(i). Further, the energy of the second branch I signal and the second branch Q signal is compared by a comparator, and the output result of the branch signal with the larger energy is selected as the final result.

Specifically, in the actual circuit design, since the radio frequency signal is divided into two channels, one is the original radio frequency signal, and the other is the modulated radio frequency signal; and each branch has two I/Q channels, so a total of 4 A branch of zero-crossing judgment. Each branch can use the symbol bit to perform XOR judgment for zero crossing. When setting the delayed start, you can configure the delayed data length through the register RADAR_ZC_DLY. The function of the start-up delay is mainly to obtain a better zero-crossing detection interval and to exclude some data affecting the signal from the head. The default value length in this embodiment is 64. The zero-crossing judgment of the I/Q signal is based on the length of the register RADAR_ZC_LEN, and the time domain data in the pulse is continuously and without interval, and there is no OVERLAP grouping. For example, the default value of the register RADAR_ZC_LEN is 128. When the length of the radio frequency signal is less than 4 groups, it will exit directly without continuing to do the linearity judgment. The corresponding register RADAR_ZC_VLD is set to 0, indicating that the zero-crossing detection result is invalid. If the signal length is greater than or equal to more than 4 packets, the output zero-crossing detection result is valid. When the number of input signal groups has exceeded 16 groups, the zero-crossing detection process is terminated. At this time, it is considered that the linearity detection data collection is sufficient. Further, in each group, the sign bit XOR is performed on the previous sampling point and the next sampling point, and the XOR result Y is accumulated in the register RADAR_ZC_LEN.

In this embodiment, the I/Q path accumulates the absolute value data of I/Q within the pulse statistics range, which can be considered as energy statistics in disguise. When linearity detection is performed, the branch with larger energy is selected. The original radio frequency signal branch and the modulated radio frequency signal branch are respectively judged for linearity, and the branch with the smaller variance is used as the final output data. Among them, the output data is the linearity detection result, and the linearity detection result includes the parameter a, the parameter b, the characteristic parameter var of the fitted straight line, and the number of effective groups N. In actual implementation, you can also set the output result as the absolute value of the difference between the cumulative value of the zero-crossing times and the fitted value, and the number of effective groups.

Specifically, the sampling points x that need to be calculated are accumulated one by one (usually set to 128 points). The value range of x is 1, 2, ... 128. For the maximum length of 100 us, the maximum grouping can be set to 47. However, from an implementation perspective, the maximum number of groups can be set to 16, and the minimum number of groups can be set to 4. That is to say, when the interception length is less than 4 groups, the output linear fitting value is meaningless, when more than 16 groups, the linear fitting operation stops. Since the number of sampling points can be calculated based on the number of groups, the reciprocal coefficient can be obtained by looking up the table. For example, it can be realized by using 10bit coefficient + shift table. As shown in Table 2, N represents the number of groups, V represents the quantized value of UINT10, and S represents the shift value. Since the scaling is 6 decimal places, the right shift value of S is reduced by 6 on an actual basis.

Table 2

NN	44	55	66	77	88	99	1010	1111	1212	1313	1414	1515	1616
VV	819819	655655	624624	669669	780780	971971	636636	867867	611611	886886	658658	999999	771771
SS	88	99	1010	1111	1212	1313	1313	1414	1414	1515	1515	1616	1616

Exemplarily, 128 sampling points are taken as a group for experimental verification. The experimental results show that when the signal-to-noise ratio of the signal is large, the linearity of the zero-crossing data is more obvious. At this time, the slope of the fitted line of the zero-crossing data can be compared with the threshold of the Chirp signal to directly distinguish the radar occupancy Frequency bands and non-radar frequency bands.

Exemplarily, after performing frequency offset processing of 10M and 20M on the radio frequency signal, and then collecting the zero-crossing data, the linearity of the zero-crossing data will become more obvious. Therefore, the problem of insignificant linearity caused by insufficient signal-to-noise ratio of the signal can be solved by processing the frequency offset of the radio frequency signal.

In this embodiment, the zero-crossing data of the radio frequency signal is obtained by performing zero-crossing detection on the received radio frequency signal; linearity detection is performed on the zero-crossing data of the radio frequency signal to obtain linearity characteristic data; if the linearity characteristic data satisfies the radar signal According to the judgment condition, it is determined that the channel corresponding to the radio frequency signal is the radar channel. Therefore, the frequency of the radar signal can be accurately detected, and the anti-interference ability is strong, so that when the wireless communication device uses the DFS frequency band, it can avoid the radar channel and ensure the normal transmission of data.

FIG. 6 is a flowchart of a channel detection method provided by another embodiment of this application. As shown in FIG. 6, the method in this embodiment may include:

S601: Perform zero-crossing detection on the received radio frequency signal to obtain zero-crossing data of the radio frequency signal.

S602: Perform linearity detection on the zero-crossing data of the radio frequency signal to obtain linearity characteristic data.

S603: If the linearity characteristic data meets the discrimination condition of the radar signal, it is determined that the frequency band corresponding to the radio frequency signal is occupied by the radar.

For the specific implementation process and implementation principle of step S601 to step S603 in this embodiment, please refer to the related description of step S201 to step S203 shown in FIG. 2, and will not be repeated here.

S604. Set the frequency band occupied by the radar as a forbidden channel for data transmission.

S605: If the linearity characteristic data does not satisfy the discrimination condition of the radar signal, it is determined that the frequency band corresponding to the radio frequency signal is the working channel.

S606: Perform data transmission through the working channel.

In this embodiment, in steps S604 to S606, the radar channel is set as the forbidden channel for data transmission, and the channel corresponding to the radio frequency signal whose linearity characteristic data does not meet the criterion of the radar signal is used as the working channel, and data is performed through the working channel. transmission. This can make full use of the DFS frequency band for frequency band expansion, and effectively avoid occupying the radar channel during data transmission, and ensure the normal transmission of data.

FIG. 7 is a schematic structural diagram of a channel detection device provided by an embodiment of the application. As shown in FIG. 7, the channel detection device 700 of this embodiment includes a memory 701 and a processor 702. The memory 701 is used to store program instructions, and the processor 702 It is used to execute the program instructions stored in the memory 701. When the program instructions are executed, the processor 702 is used to:

Perform zero-crossing detection on the received radio frequency signal to obtain the zero-crossing data of the radio frequency signal;

Perform linearity detection on the zero-crossing data of the radio frequency signal to obtain linearity characteristic data;

Optionally, the processor 702 is further configured to:

Divide the received radio frequency signal into two channels to obtain the first channel signal and the second channel signal; among them, the first channel signal and the second channel signal are the same;

Perform zero-crossing detection on the first signal to obtain the zero-crossing data of the first signal;

Perform modulation processing on the second signal to obtain a modulated signal;

Perform zero-crossing detection on the modulated signal to obtain the zero-crossing data of the second signal.

Optionally, the processor 702 is further configured to:

The phase angle of the second signal is modulated to obtain a modulated signal.

Optionally, the processor 702 is further configured to:

Perform linearity detection on the zero-crossing data of the first signal and the zero-crossing data of the second signal, respectively, to obtain the linearity characteristic data of the first signal and the linearity characteristic data of the second signal.

Optionally, the processor 702 is further configured to:

If the linearity characteristic data of the first signal and/or the linearity characteristic data of the second signal meet the radar signal discrimination condition, it is determined that the frequency band corresponding to the radio frequency signal is occupied by the radar.

Optionally, the judgment condition of the radar signal includes: the slope of the fitted straight line corresponding to the linearity characteristic data is smaller than the threshold of the radar signal.

Optionally, the processor 702 is further configured to:

Determine the time range for turning on radio frequency signal reception, and receive radio frequency signals within the time range.

Optionally, the processor 702 is further configured to:

Sampling the radio frequency signal to obtain sampled data;

The sampled data is divided into groups to obtain multiple grouped data; among them, each grouped data contains the same number of sampling points;

Perform zero-crossing detection on each packet data to obtain zero-crossing data; the zero-crossing data is related to the frequency of the radio frequency signal.

Optionally, the processor 702 is further configured to:

Compare the signals of adjacent sampling points in the packet data in turn;

If the sign bits of the signals of adjacent sampling points are different, the number of zero-crossings is increased by one; among them, the zero-crossing data is the total number of times the packet data passes through the zero point.

Optionally, the processor 702 is further configured to:

The fitting operation is performed on the zero-crossing data to obtain the characteristic parameters of the fitted straight line; the characteristic parameters of the fitted straight line constitute the linearity characteristic data.

Optionally, the processor 702 is further configured to:

By looking up the table, the characteristic parameters of the fitted straight line corresponding to the zero-crossing data are determined; the characteristic parameters of the fitted straight line constitute the linearity characteristic data.

Optionally, the processor 702 is further configured to:

Determine the slope of the fitted straight line according to the characteristic parameters of the fitted straight line;

If the slope of the fitted straight line is less than the threshold of the radar signal, it is determined that the frequency band corresponding to the radio frequency signal is occupied by the radar.

Optionally, the processor 702 is further configured to:

Set the frequency band occupied by the radar as the forbidden channel for data transmission.

Optionally, the processor 702 is further configured to:

If the linearity characteristic data does not meet the discrimination conditions of the radar signal, the frequency band corresponding to the radio frequency signal is determined as the working channel;

Data transmission through the working channel.

An embodiment of the present application also provides an unmanned aerial vehicle, which applies the channel detection method shown in FIG. 2, FIG. 3, and FIG. 6, when the frequency band corresponding to the radio frequency signal is occupied by the radar, the frequency band occupied by the radar is disabled as the communication channel.

The embodiment of the application also provides a remote controller for a movable platform, which uses the channel detection method shown in Figure 2, Figure 3, and Figure 6 to communicate with the drone. When the frequency band corresponding to the radio frequency signal is occupied by radar, Disable the frequency band occupied by the radar as the communication channel.

Optionally, the movable platform includes one of a drone, a ground mobile robot, and an unmanned vehicle.

A person of ordinary skill in the art can understand that all or part of the steps in the above method embodiments can be implemented by a program instructing relevant hardware. The foregoing program can be stored in a computer readable storage medium. When the program is executed, it is executed. Including the steps of the foregoing method embodiment; and the foregoing storage medium includes: read-only memory (Read-Only Memory, ROM), random access memory (Random Access Memory, RAM), magnetic disks or optical disks, etc., which can store program codes Medium.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the application, not to limit them; although the application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: It is still possible to modify the technical solutions described in the foregoing embodiments, or equivalently replace some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the technical solutions of the embodiments of the present application. range.

Claims

A channel detection method, characterized in that it comprises:

Performing zero-crossing detection on the received radio frequency signal to obtain zero-crossing data of the radio frequency signal;

Performing linearity detection on the zero-crossing data of the radio frequency signal to obtain linearity characteristic data;

If the linearity characteristic data meets the discrimination condition of the radar signal, it is determined that the frequency band corresponding to the radio frequency signal is occupied by the radar.
The method according to claim 1, wherein the performing zero-crossing detection on the received radio frequency signal to obtain zero-crossing data of the radio frequency signal comprises:

Divide the received radio frequency signal into two channels to obtain a first channel signal and a second channel signal; wherein, the first channel signal and the second channel signal are the same;

Performing zero-crossing detection on the first signal to obtain zero-crossing data of the first signal;

Performing modulation processing on the second signal to obtain a modulated signal;

Performing zero-crossing detection on the modulation signal to obtain zero-crossing data of the second signal.
The method according to claim 2, wherein performing modulation processing on the second signal to obtain a modulated signal comprises:

The phase angle of the second signal is modulated to obtain the modulated signal.
The method according to claim 2, wherein performing linearity detection on the zero-crossing data of the radio frequency signal to obtain linearity characteristic data comprises:

Linearity detection is performed on the zero-crossing data of the first signal and the zero-crossing data of the second signal, respectively, to obtain the linearity characteristic data of the first signal and the linearity characteristic data of the second signal.
The method according to claim 3, characterized in that, if the linearity characteristic data satisfies the discrimination condition of the radar signal, determining that the frequency band corresponding to the radio frequency signal is occupied by the radar comprises:

If the linearity characteristic data of the first signal and/or the linearity characteristic data of the second signal satisfy the radar signal discrimination condition, it is determined that the frequency band corresponding to the radio frequency signal is occupied by the radar.
The method according to any one of claims 1 to 5, wherein the judgment condition of the radar signal comprises: the slope of the fitting straight line corresponding to the linearity characteristic data is smaller than the threshold of the radar signal.
The method according to any one of claims 1-5, wherein before performing zero-crossing detection on the received radio frequency signal, the method further comprises:

Determine the time range for turning on the radio frequency signal reception, and receive the radio frequency signal within the time range.
The method according to any one of claims 1-5, wherein the performing zero-crossing detection on the received radio frequency signal to obtain zero-crossing data comprises:

Sampling the radio frequency signal to obtain sampling data;

Grouping and segmenting the sampled data to obtain a plurality of grouped data; wherein, each grouped data contains the same number of sampling points;

Performing zero-crossing detection on each packet data to obtain zero-crossing data; the zero-crossing data is related to the frequency of the radio frequency signal.
The method according to claim 8, wherein said performing zero-crossing detection on each packet data to obtain zero-crossing data comprises:

Sequentially comparing the signals of adjacent sampling points in the grouped data;

If the sign bits of the signals of adjacent sampling points are different, the number of zero-crossings is increased by one; wherein, the zero-crossing data is the total number of times the packet data passes through the zero point.
The method according to any one of claims 1 to 5, wherein performing linearity detection on the zero-crossing data to obtain linearity characteristic data comprises:

A fitting operation is performed on the zero-crossing data to obtain characteristic parameters of the fitted straight line; the characteristic parameters of the fitted straight line constitute the linearity characteristic data.
The method according to any one of claims 1 to 5, wherein performing linearity detection on the zero-crossing data to obtain linearity characteristic data comprises:

The characteristic parameters of the fitted straight line corresponding to the zero-crossing data are determined by looking up the table; the characteristic parameters of the fitted straight line constitute the linearity characteristic data.
The method according to claim 10 or 11, wherein if the linearity characteristic data satisfies the discrimination condition of the radar signal, determining that the frequency band corresponding to the radio frequency signal is occupied by the radar includes:

Determine the slope of the fitted straight line according to the characteristic parameters of the fitted straight line;

If the slope of the fitted straight line is less than the threshold of the radar signal, it is determined that the frequency band corresponding to the radio frequency signal is occupied by the radar.
The method according to any one of claims 1-5, further comprising:

Set the frequency band occupied by the radar as the forbidden channel for data transmission.
The method according to any one of claims 1-5, further comprising:

If the linearity characteristic data does not satisfy the discrimination condition of the radar signal, determining that the frequency band corresponding to the radio frequency signal is the working channel;

Data transmission is performed through the working channel.
A channel detection device, characterized by comprising a memory and a processor, the memory is used to store program instructions, the processor is used to execute the program instructions stored in the memory, and when the program instructions are executed, the The processor is used for:

Performing zero-crossing detection on the received radio frequency signal to obtain zero-crossing data of the radio frequency signal;

Performing linearity detection on the zero-crossing data of the radio frequency signal to obtain linearity characteristic data;

If the linearity characteristic data meets the discrimination condition of the radar signal, it is determined that the frequency band corresponding to the radio frequency signal is occupied by the radar.
The device according to claim 15, wherein the processor is further configured to:

Divide the received radio frequency signal into two channels to obtain a first channel signal and a second channel signal; wherein, the first channel signal and the second channel signal are the same;

Performing zero-crossing detection on the first signal to obtain zero-crossing data of the first signal;

Performing modulation processing on the second signal to obtain a modulated signal;

Performing zero-crossing detection on the modulation signal to obtain zero-crossing data of the second signal.
The device according to claim 16, wherein the processor is further configured to:

The phase angle of the second signal is modulated to obtain the modulated signal.
The device according to claim 16, wherein the processor is further configured to:

Linearity detection is performed on the zero-crossing data of the first signal and the zero-crossing data of the second signal, respectively, to obtain the linearity characteristic data of the first signal and the linearity characteristic data of the second signal.
The device according to claim 18, wherein the processor is further configured to:

If the linearity characteristic data of the first signal and/or the linearity characteristic data of the second signal satisfy the radar signal discrimination condition, it is determined that the frequency band corresponding to the radio frequency signal is occupied by the radar.
The device according to any one of claims 15-19, wherein the judgment condition of the radar signal comprises: the slope of the fitting straight line corresponding to the linearity characteristic data is smaller than the threshold of the radar signal.
The device according to any one of claims 15-19, wherein the processor is further configured to:

Determine the time range for turning on the radio frequency signal reception, and receive the radio frequency signal within the time range.
The device according to any one of claims 15-19, wherein the processor is further configured to:

Sampling the radio frequency signal to obtain sampling data;

Grouping and segmenting the sampling data to obtain a plurality of grouping data; wherein, each grouping data includes the same number of sampling points;

Performing zero-crossing detection on each packet data to obtain zero-crossing data; the zero-crossing data is related to the frequency of the radio frequency signal.
The device according to claim 22, wherein the processor is further configured to:

Sequentially comparing the signals of adjacent sampling points in the grouped data;

If the sign bits of the signals of adjacent sampling points are different, the number of zero-crossings is increased by one; wherein, the zero-crossing data is the total number of times the packet data passes through the zero point.
The device according to any one of claims 15-19, wherein the processor is further configured to:

A fitting operation is performed on the zero-crossing data to obtain characteristic parameters of the fitted straight line; the characteristic parameters of the fitted straight line constitute the linearity characteristic data.
The device according to any one of claims 15-19, wherein the processor is further configured to:

The characteristic parameters of the fitted straight line corresponding to the zero-crossing data are determined by looking up the table; the characteristic parameters of the fitted straight line constitute the linearity characteristic data.
The device according to claim 24 or 25, wherein the processor is further configured to:

Determine the slope of the fitted straight line according to the characteristic parameters of the fitted straight line;

If the slope of the fitted straight line is less than the threshold of the radar signal, it is determined that the frequency band corresponding to the radio frequency signal is occupied by the radar.
The device according to any one of claims 15-19, wherein the processor is further configured to:

Set the frequency band occupied by the radar as the forbidden channel for data transmission.
The device according to any one of claims 15-19, wherein the processor is further configured to:

If the linearity characteristic data does not satisfy the discrimination condition of the radar signal, determining that the frequency band corresponding to the radio frequency signal is the working channel;

Data transmission is performed through the working channel.
A readable storage medium, wherein a computer program is stored on the readable storage medium; when the computer program is executed, the channel detection method according to any one of claims 1-14 is executed.
An unmanned aerial vehicle, characterized in that the channel detection method according to any one of claims 1-14 is applied, and when the frequency band corresponding to the radio frequency signal is occupied by radar, the frequency band occupied by the radar is disabled as communication channel.
A remote control for a movable platform, characterized in that the channel detection method according to any one of claims 1-14 is applied, and when the frequency band corresponding to the radio frequency signal is occupied by radar, the The frequency band is used as a communication channel.
The remote control according to claim 31, wherein the movable platform includes one of an unmanned aerial vehicle, a ground mobile robot, and an unmanned vehicle.