CN113765541B

CN113765541B - Unmanned aerial vehicle frequency hopping communication method and device, computer equipment and storage medium

Info

Publication number: CN113765541B
Application number: CN202111117279.8A
Authority: CN
Inventors: 陈昌才; 苏重来; 朱文峰; 杨昳; 陈珍; 陈隆亮
Original assignee: Chengdu Vocational and Technical College of Industry
Current assignee: Chengdu Vocational and Technical College of Industry
Priority date: 2021-09-23
Filing date: 2021-09-23
Publication date: 2023-03-24
Anticipated expiration: 2041-09-23
Also published as: CN113765541A

Abstract

The invention relates to the technical field of unmanned aerial vehicle communication, and discloses an unmanned aerial vehicle frequency hopping communication method, an unmanned aerial vehicle frequency hopping communication device, computer equipment and a storage medium. The invention provides a frequency hopping communication scheme for dynamically generating a consensus frequency hopping sequence based on a channel estimation technology, namely, on the premise of not depending on a special frequency hopping system, a frequency hopping sequence which does not need to be agreed in advance can be dynamically generated between a common ground station (or an unmanned aerial vehicle) and the unmanned aerial vehicle, so that the dynamic networking requirements between different unmanned aerial vehicles and the ground station can be met, both communication parties of the unmanned aerial vehicle can continuously switch frequency points for communication according to time slices based on the generated frequency hopping sequence, the unmanned aerial vehicle based on the frequency hopping sequence dynamic generation mode can also carry out frequency hopping communication, the communication confidentiality is greatly improved, an eavesdropper is prevented from carrying out information stealing, the hardware and cost limitations of a military frequency hopping mode are eliminated, and the scheme is suitable for special application scenes.

Description

Unmanned aerial vehicle frequency hopping communication method and device, computer equipment and storage medium

Technical Field

The invention belongs to the technical field of unmanned aerial vehicle communication, and particularly relates to an unmanned aerial vehicle frequency hopping communication method, an unmanned aerial vehicle frequency hopping communication device, computer equipment and a storage medium.

Background

With the rapid development of unmanned aerial vehicle technology, more and more tasks can be performed by unmanned aerial vehicles. However, at present, radio signals between the unmanned aerial vehicle and the unmanned aerial vehicle or between the unmanned aerial vehicle and the ground station are generally transmitted in a fixed-frequency communication mode, and there is a hidden danger of interception, although part of the unmanned aerial vehicles have upper-layer security protocols to encrypt data, in view of the broadcast physical characteristics of the radio signals, the risk of interception and brute force cracking is high, and especially when some major tasks are executed or sensitive information is transmitted, the communication safety is not guaranteed.

Although above-mentioned problem can be solved through the frequency hopping system that introduces military frequency hopping radio station system, but dedicated frequency hopping technique is difficult commercial popularization because reasons such as the secret requirement of military and square, and it relies on special hardware simultaneously, has greatly increased the unmanned aerial vehicle cost.

Disclosure of Invention

In order to solve the problems that the communication safety is not reliable and the limitation of a military frequency hopping mode exists in the existing unmanned aerial vehicle communication technology, the invention aims to provide a novel unmanned aerial vehicle frequency hopping communication method, a device, computer equipment and a storage medium, which can be independent of a special frequency hopping system, dynamically generate a frequency hopping sequence without appointment in advance between a common ground station (or an unmanned aerial vehicle) and the unmanned aerial vehicle, and further can meet the dynamic networking requirements between different unmanned aerial vehicles and the ground station.

In a first aspect, the present invention provides a frequency hopping communication method for an unmanned aerial vehicle, for interactive execution between a first unmanned aerial vehicle or a ground station and a second unmanned aerial vehicle, including:

the first unmanned aerial vehicle or the ground station communicates with the second unmanned aerial vehicle on a communication link established based on the current communication frequency point to complete the synchronization of a local first frequency hopping clock and a second frequency hopping clock of the second unmanned aerial vehicle;

transmitting, by a first drone or ground station, a channel sounding signal over the communication link;

when receiving the channel detection signal, the second unmanned aerial vehicle acquires a second channel state information estimation value in a channel estimation mode and sends back the channel detection signal;

when the first unmanned machine or the ground station receives the channel detection signal, a first channel state information estimation value is obtained through the channel estimation mode;

carrying out bit value quantization processing on the first channel state information estimation value by a first unmanned aerial vehicle or a ground station to obtain a first key, and carrying out bit value quantization processing on the second channel state information estimation value by a second unmanned aerial vehicle to obtain a second key;

performing hash algorithm processing on the first key by a first unmanned aerial vehicle or a ground station to obtain a first hash value, and performing the hash algorithm processing on the second key by a second unmanned aerial vehicle to obtain a second hash value;

transmitting, by a first drone or ground station, the first hash value over the communication link;

after receiving the first hash value, the second unmanned aerial vehicle judges whether the first hash value is the same as the second hash value, and returns a judgment result;

after the first unmanned machine or the ground station receives the judgment result, if the judgment result indicates that the first hash value is the same as the second hash value, performing frequency hopping mapping processing on the first key to obtain a first frequency hopping sequence, wherein the first frequency hopping sequence comprises at least one new communication frequency point to be hopped;

when the first frequency hopping clock reaches the appointed frequency hopping time, a first unmanned aerial vehicle or a ground station switches to a new communication frequency point according to the first frequency hopping sequence so as to establish a new communication link with a second unmanned aerial vehicle which switches to the new communication frequency point according to a second frequency hopping sequence when the second frequency hopping clock reaches the appointed frequency hopping time, wherein the second frequency hopping sequence is obtained by the second unmanned aerial vehicle performing the frequency hopping mapping processing on the second key when the first hash value is judged to be the same as the second hash value, so that the second frequency hopping sequence is the same as the first frequency hopping sequence.

Based on the content of the invention, a frequency hopping communication scheme for dynamically generating a consensus frequency hopping sequence based on a channel estimation technology is provided, namely based on the reciprocity principle of a channel, two frequency hopping communication parties respectively carry out channel estimation through interactive channel detection signals to obtain channel state information estimated values in a random complex form, then carry out the same bit numerical value quantization processing on the corresponding channel state information estimated values on two sides to obtain theoretically the same secret key, then carry out consistency check on the secret keys obtained on the two sides through the hash value of the interactive secret key, and finally enable the two parties to obtain the same frequency hopping sequence according to the mapping of the consensus key when the consistency check is passed.

In one possible design, the synchronization of the local first frequency hopping clock and the second frequency hopping clock of the second drone is completed by the first drone or the ground station communicating with the second drone over a communication link established based on the current communication frequency point, including:

the first unmanned aerial vehicle or the ground station sends a frequency hopping starting signal to the second unmanned aerial vehicle on a communication link established based on the current communication frequency point;

when the second unmanned aerial vehicle receives the frequency hopping starting signal, a corresponding response signal is sent back, and the time of a second frequency hopping clock of the second unmanned aerial vehicle is initialized to zero time;

and initializing the time of a local first frequency hopping clock to zero time when the first unmanned machine or the ground station receives the response signal, so that the first frequency hopping clock is synchronous with the second frequency hopping clock.

In one possible design, performing bit value quantization on the first csi estimate by a first drone or ground station to obtain a first key, includes:

after K first channel state information estimated values are obtained based on the channel detection signals which are sent and sent back for K times continuously by a first unmanned machine or a ground station, the K first channel state information estimated values are respectively subjected to normalization processing to obtain K first normalization values, wherein K represents a natural number which is greater than or equal to two;

respectively carrying out bit digit value quantization processing on the K first normalization values by a first unmanned machine or a ground station to obtain K first bit strings;

and sequentially combining the K first bit strings by a first unmanned machine or a ground station according to the sending time sequence or the back sending time sequence of the channel detection signal to obtain the first secret key.

dividing an amplitude change interval of the first channel state information estimation value into M amplitude change subintervals by a first unmanned machine or a ground station, and carrying out bit numerical value quantization processing on the amplitude of the first channel state information estimation value according to the following mode: when the amplitude belongs to a certain amplitude variation subinterval among the M amplitude variation subintervals, the quantized value of the amplitude is a preset bit value which corresponds to the certain amplitude variation subinterval and has X bits, wherein M and X respectively represent natural numbers which are greater than or equal to two;

dividing a phase change interval of the first channel state information estimation value into N phase change subintervals by a first unmanned machine or a ground station, and carrying out bit numerical value quantization processing on the phase of the first channel state information estimation value according to the following mode: when the phase belongs to a certain phase change subinterval in the N phase change subintervals, the quantized value of the phase is a preset bit value which corresponds to the certain phase change subinterval and has the X bits, wherein N represents a natural number which is greater than or equal to two;

and performing exclusive OR operation on the result of performing bit numerical quantization on the amplitude of the first channel state information estimation value and the result of performing bit numerical quantization on the phase of the first channel state information estimation value by using a first unmanned machine or a ground station to obtain a first key.

In one possible design, the hashing the first key by a first drone or a ground station to obtain a first hash value, and the hashing the second key by a second drone to obtain a second hash value, includes:

the first key is segmented by a first unmanned aerial vehicle or a ground station to obtain Y first key segments, and the second key is segmented by a second unmanned aerial vehicle to obtain Y second key segments, wherein Y represents a natural number greater than or equal to two;

processing each first key segment in the Y first key segments by a first unmanned aerial vehicle or a ground station through a hash algorithm to obtain a corresponding first hash value, and processing each second key segment in the Y second key segments by a second unmanned aerial vehicle through the hash algorithm to obtain a corresponding second hash value;

transmitting, by a first drone or ground station, the first hash value over the communication link, comprising: transmitting Y first hash values corresponding to the Y first key fragments one to one on the communication link;

after receiving the first hash value, the second drone judges whether the first hash value is the same as the second hash value, and returns a judgment result, including: after the second unmanned aerial vehicle receives the Y first hash values, judging whether the first hash values are the same as corresponding second hash values in the Y second hash values or not according to the first hash values in the Y first hash values, and returning a judgment result;

after the first unmanned machine or the ground station receives the determination result, if the determination result indicates that the first hash value is the same as the second hash value, performing frequency hopping mapping processing on the first key to obtain a first frequency hopping sequence, including: after the first unmanned machine or the ground station receives the judgment result, if the judgment result indicates that Z first hash values are different from the corresponding second hash values, first key fragments corresponding to all the first hash values in the Z first hash values are removed from the first key to obtain a new first key, and then frequency hopping mapping processing is carried out on the new first key to obtain a first frequency hopping sequence, wherein Z represents a natural number smaller than Y, and the first frequency hopping sequence comprises at least one new communication frequency point to be hopped.

Based on the possible design, the number of times of re-obtaining a new key can be reduced by confirming the key consistency in a segmented manner, the time required for generating the frequency hopping sequence is shortened, the success rate of generating the frequency hopping sequence and carrying out frequency hopping communication is improved, and the influence of factors such as noise is avoided.

In a second aspect, the present invention provides an unmanned aerial vehicle frequency hopping communication device, arranged in a first unmanned aerial vehicle or a ground station, comprising a first clock synchronization module, a first signal transceiver module, a first channel estimation module, a first quantization processing module, a first hash processing module, a first data transceiver module, a first mapping processing module and a first frequency hopping execution module;

the first clock synchronization module is used for communicating with a second unmanned aerial vehicle on a communication link established based on the current communication frequency point to complete synchronization of a local first frequency hopping clock and a second frequency hopping clock of the second unmanned aerial vehicle;

the first signal transceiver module is configured to send a channel sounding signal on the communication link, so that when the second unmanned aerial vehicle receives the channel sounding signal, a second channel state information estimation value is obtained in a channel estimation manner, and the first signal transceiver module sends back the channel sounding signal and is configured to receive the channel sounding signal;

the first channel estimation module is in communication connection with the first signal transceiver module and is used for acquiring a first channel state information estimation value in the channel estimation mode when the channel detection signal is received;

the first quantization processing module is in communication connection with the first channel estimation module and is configured to perform bit value quantization processing on the first channel state information estimation value to obtain a first key;

the first hash processing module is in communication connection with the first quantization processing module and is used for performing hash algorithm processing on the first key to obtain a first hash value;

the first data transceiver module is communicatively connected to the first hash processing module, and is configured to transmit the first hash value over the communication link, so that the second unmanned aerial vehicle, after receiving the first hash value, determines whether the first hash value is the same as the second hash value, and returns a determination result, and is configured to receive the determination result, where the second hash value is obtained by the second unmanned aerial vehicle by performing the hash algorithm processing on a second key, and the second key is obtained by the second unmanned aerial vehicle by performing the bit value quantization processing on the second channel state information estimation value;

the first mapping processing module is communicatively connected to the first data transceiver module, and configured to perform frequency hopping mapping processing on the first key to obtain a first frequency hopping sequence after receiving the determination result, where the determination result indicates that the first hash value is the same as the second hash value, and the first frequency hopping sequence includes at least one new communication frequency point to be hopped;

the first frequency hopping execution module is respectively in communication connection with the first clock synchronization module and the first mapping processing module and is used for switching to a new communication frequency point according to the first frequency hopping sequence when the first frequency hopping clock reaches an appointed frequency hopping moment so as to be switched to the second unmanned aerial vehicle on the new communication frequency point according to the second frequency hopping sequence when the second frequency hopping clock reaches the appointed frequency hopping moment to establish a new communication link, wherein the second frequency hopping sequence is obtained by the second unmanned aerial vehicle by judging that the first hash value is the same as the second hash value and performing frequency hopping mapping processing on the second key, so that the second frequency hopping sequence is the same as the first frequency hopping sequence.

In a third aspect, the present invention provides another frequency hopping communication device for an unmanned aerial vehicle, which is disposed in a second unmanned aerial vehicle and includes a second clock synchronization module, a second signal transceiver module, a second channel estimation module, a second quantization processing module, a second hash processing module, a second data transceiver module, a second mapping processing module, and a second frequency hopping execution module;

the second clock synchronization module is used for communicating with a first unmanned machine or a ground station on a communication link established based on the current communication frequency point to complete the synchronization of a local second frequency hopping clock and the first frequency hopping clock of the first unmanned machine or the ground station;

the second signal transceiving module is configured to receive a channel sounding signal sent by the first drone or the ground station on the communication link, and send back the channel sounding signal, so that the first drone or the ground station obtains a first channel state information estimation value in a channel estimation manner when receiving the channel sounding signal;

the second channel estimation module is communicatively connected to the second signal transceiver module, and is configured to obtain a second channel state information estimation value in the channel estimation manner when receiving the channel detection signal;

the second quantization processing module is in communication connection with the second channel estimation module and is configured to perform bit value quantization processing on the second channel state information estimation value to obtain a second key;

the second hash processing module is in communication connection with the second quantization processing module and is configured to perform hash algorithm processing on the second key to obtain a second hash value;

the second data transceiver module is configured to receive, over the communication link, a first hash value transmitted by the first drone or the ground station, where the first hash value is obtained by the first drone or the ground station through the hash algorithm processing on a first key, and the first key is obtained by the first drone or the ground station through the bit number quantization processing on the first channel state information estimation value;

the second mapping processing module is respectively in communication connection with the second data transceiver module and the second hash processing module, and is configured to determine whether the first hash value is the same as the second hash value after receiving the first hash value, obtain a determination result, and perform frequency hopping mapping processing on the second key when determining that the first hash value is the same as the second hash value, to obtain a second frequency hopping sequence, where the second frequency hopping sequence includes at least one new communication frequency point to be hopped;

the second data transceiver module is further configured to transmit the determination result back;

the second frequency hopping execution module is respectively in communication connection with the second clock synchronization module and the second mapping processing module, and is used for switching to a new communication frequency point according to the second frequency hopping sequence when the second frequency hopping clock reaches an agreed frequency hopping moment so as to establish a new communication link with the first unmanned machine or the ground station which is switched to the new communication frequency point according to the first frequency hopping sequence when the first frequency hopping clock reaches the agreed frequency hopping moment, wherein the first frequency hopping sequence is obtained by performing the frequency hopping mapping processing on the first key when the first unmanned machine or the ground station receives the judgment result and the judgment result indicates that the first hash value is the same as the second hash value, so that the first frequency hopping sequence is the same as the second frequency hopping sequence.

In a fourth aspect, the present invention provides a computer device comprising a memory, a processor and a transceiver communicatively connected in sequence, wherein the memory is used for storing a computer program, the transceiver is used for transceiving signals, and the processor is used for reading the computer program and executing the drone frequency hopping communication method as described in the first aspect or any possible design of the first aspect and executed by a first drone or ground station or executed by a second drone.

In a fifth aspect, the present invention provides a computer readable storage medium having stored thereon instructions which, when run on a computer, perform a drone frequency hopping communication method as described above in the first aspect or any of the possible designs thereof and executed by a first drone or ground station or executed by a second drone.

In a sixth aspect, the present invention provides a computer program product containing instructions which, when run on a computer, cause the computer to perform a drone frequency hopping communication method as described above in the first aspect or any of the possible designs of the first aspect and performed by a first drone or a ground station or by a second drone.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

Fig. 1 is an interaction flow diagram of the frequency hopping communication method for the unmanned aerial vehicle provided by the invention.

Fig. 2 is a schematic structural diagram of a first frequency hopping communication device of an unmanned aerial vehicle provided by the invention.

Fig. 3 is a schematic structural diagram of a second frequency hopping communication device for an unmanned aerial vehicle according to the present invention.

Fig. 4 is a schematic structural diagram of a computer device provided by the present invention.

Detailed Description

The invention is further described with reference to the following figures and specific embodiments. It should be noted that the description of the embodiments is provided to help understanding of the present invention, but the present invention is not limited thereto. Specific structural and functional details disclosed herein are merely representative of exemplary embodiments of the invention. The present invention may, however, be embodied in many alternate forms and should not be construed as limited to the embodiments set forth herein.

It will be understood that, although the terms first, second, etc. may be used herein to describe various objects, these objects should not be limited by these terms. These terms are only used to distinguish one object from another. For example, a first object may be referred to as a second object, and similarly, a second object may be referred to as a first object, without departing from the scope of example embodiments of the present invention.

It should be understood that, for the term "and/or" as may appear herein, it is merely an associative relationship that describes an associated object, meaning that three relationships may exist, e.g., a and/or B may mean: a exists alone, B exists alone or A and B exist at the same time; for the term "/and" as may appear herein, which describes another associative object relationship, it means that two relationships may exist, e.g., a/and B, may mean: a exists singly or A and B exist simultaneously; in addition, for the character "/" that may appear herein, it generally means that the former and latter associated objects are in an "or" relationship.

As shown in fig. 1, the frequency hopping communication method for an unmanned aerial vehicle according to the first aspect of the present embodiment is used for performing interaction between a first unmanned aerial vehicle or a ground station and a second unmanned aerial vehicle, so as to solve the problem that the communication security of the existing unmanned aerial vehicle is not reliable and the limitation problem of the military frequency hopping mode exists, that is, on the premise of not depending on a dedicated frequency hopping system, a frequency hopping sequence which does not need to be agreed in advance can be dynamically generated between a common ground station (or an unmanned aerial vehicle) and an unmanned aerial vehicle, and further, the dynamic networking requirements between different unmanned aerial vehicles and the ground station can be met. As shown in fig. 1, the method for frequency hopping communication of the drone may include, but is not limited to, the following steps S1 to S10.

S1, a first unmanned aerial vehicle or a ground station communicates with a second unmanned aerial vehicle on a communication link established based on a current communication frequency point to complete synchronization of a local first frequency hopping clock and a second frequency hopping clock of the second unmanned aerial vehicle.

In step S1, since both frequency hopping communication parties (i.e. the first drone or the ground station and the second drone) need to switch to the same communication frequency point within the same time slice to successfully establish a communication link for normal communication, the built-in frequency hopping clocks of both frequency hopping communication parties need to be synchronized first. The current communication frequency point is the center frequency of the modulation signal in the current communication process, and may be a default known frequency point or a predetermined frequency point to which both frequency hopping communication parties hop frequency together in a certain time slice. In addition, the specific mode of establishing the communication link based on the current communication frequency point is an existing conventional mode so as to ensure that two frequency hopping communication parties can normally communicate.

Specifically, the first unmanned aerial vehicle or the ground station communicates with the second unmanned aerial vehicle on a communication link established based on the current communication frequency point to complete synchronization of the local first frequency hopping clock and the second frequency hopping clock of the second unmanned aerial vehicle, including but not limited to the following steps S11 to S13.

And S11, sending a frequency hopping starting signal to the second unmanned aerial vehicle by the first unmanned aerial vehicle or the ground station on a communication link established based on the current communication frequency point.

In step S11, the frequency hopping start signal is used to be transmitted when a drone communication system (i.e., a communication system formed by the first drone or the ground station and the second drone) starts frequency hopping communication, so as to instruct the second drone to initialize a built-in frequency hopping clock as a start instruction signal.

And S12, when the second unmanned aerial vehicle receives the frequency hopping starting signal, sending back a corresponding response signal, and initializing the time of a second frequency hopping clock of the second unmanned aerial vehicle to zero time.

In step S12, the response signal may be, but is not limited to, the frequency hopping initiation signal.

And S13, when the first unmanned machine or the ground station receives the response signal, initializing the time of a local first frequency hopping clock to zero time, so that the first frequency hopping clock is synchronous with the second frequency hopping clock.

In step S13, after the time is initialized to zero, the first frequency hopping clock and the second frequency hopping clock both advance according to the normal clock for seconds, so that both the frequency hopping communication parties switch the communication frequency points in the same time slice. In addition, since the communication distance between the first drone or the ground station and the second drone in an actual drone communication system is much shorter than the transmission distance in seconds of radio signals (including but not limited to the hopping start signal and the response signal), the time delay for propagating the response signal can be ignored, and the second hopping clock and the first hopping clock initialized at the transmission time and the reception time of the response signal, respectively, are regarded as two internal clocks that are synchronized.

And S2, sending a channel detection signal on the communication link by the first unmanned machine or the ground station.

In step S2, the channel sounding signal may be sent when a first preset time period T1 (e.g., 10 seconds) after the first frequency hopping clock is initialized arrives. The specific content of the Channel sounding signal needs to be agreed in advance by both frequency hopping communication parties and contains known data of both parties, so that both parties can perform Channel sounding based on the Channel sounding signal and estimate the value of corresponding Channel State Information (CSI, which is Information used for estimating the characteristics of a communication link).

And S3, when the second unmanned aerial vehicle receives the channel detection signal, acquiring a second channel state information estimation value in a channel estimation mode, and sending back the channel detection signal.

In step S3, since the performance of the wireless communication system is greatly affected by the wireless channel, such as shadow fading and frequency selective fading, so that the propagation path between the transmitter and the receiver is very complex, and the wireless channel is not fixed and predictable like a wired channel and has great randomness, which poses a great challenge to the design of the receiver, in order to accurately recover the transmitted signal at the transmitter end, various measures need to be taken to resist the influence of the multipath effect on the transmitted signal. Meanwhile, because the implementation of the channel estimation technology requires to know the information of the wireless channel, such as the channel order, the doppler shift, the multipath delay, or the impulse response of the channel, the channel parameter estimation is a key existing technology for implementing the wireless communication system, so that the channel estimation mode can specifically adopt a mode commonly used in the existing channel detection, for example, a least square channel estimation mode to perform channel estimation, and obtain the second channel state information estimation value. The second csi estimate is derived from the amplitude and phase of each subcarrier corresponding to the Frequency domain space after decoding in an OFDM (Orthogonal Frequency Division Multiplexing) system, and thus is a random complex number including the amplitude and the phase.

And S4, when the first unmanned machine or the ground station receives the channel detection signal, acquiring a first channel state information estimation value in a channel estimation mode.

In step S4, the time delay for propagating the channel sounding signal is also ignored, and the channel states corresponding to the sending time and the receiving time of the channel sounding signal are regarded as unchanged, so that the two frequency hopping communication parties can obtain the same or highly similar channel state information estimation values according to the reciprocity principle of the channel; and for any third party with different positions with the frequency hopping communication party, even if the same channel estimation mode is adopted according to the channel detection signal, the obtained channel state information estimation value is obviously different from the first channel state information estimation value and the second channel state information estimation value, and the confidentiality and the security of the subsequent obtained frequency hopping sequence are ensured. And in order to further ensure that both frequency hopping communication parties obtain the same or highly similar channel state information estimation values, the channel estimation mode needs to be the same as the channel estimation mode in step S3. Similarly, the first csi estimate is a random complex number with amplitude and phase. In addition, considering that the unmanned plane flies at a certain speed, so that the channel has time-varying characteristics, so as to obtain more channel state information estimated values for obtaining the subsequent consensus key, the foregoing steps S2 to S4 may be repeatedly performed to obtain a plurality of first channel state information estimated values and second channel state information estimated values which are respectively random complex numbers; in theory, the first csi estimate and the second csi estimate obtained each time the aforementioned steps S2 to S4 are performed would be the same random complex number.

And S5, carrying out bit value quantization processing on the first channel state information estimated value by a first unmanned aerial vehicle or a ground station to obtain a first secret key, and carrying out bit value quantization processing on the second channel state information estimated value by a second unmanned aerial vehicle to obtain a second secret key.

In step S5, the bit value quantization process is to quantize and convert the first channel state information estimation value and the second channel state information estimation value into bit strings with a certain length, so as to obtain the first key and the second key. Since both sides of the frequency hopping communication adopt the same bit value quantization processing mode, theoretically, the first secret key and the second secret key are also the same and can be used as a consensus secret key for generating a subsequent frequency hopping sequence to obtain the same frequency hopping sequence.

In step S5, considering that there may be a hardware inconsistency between the first drone or the ground station and the first drone, such as a signal amplifier, in order to ensure that the first channel state information estimation value and the second channel state information estimation value can be quantized to obtain the same bit string, it is preferable that the first drone or the ground station performs a bit number value quantization process on the first channel state information estimation value to obtain the first key, including but not limited to steps S511 to S513.

And S511, after K first channel state information estimated values are obtained by the first unmanned machine or ground station based on the channel detection signals which are sent and sent back for K times continuously, the K first channel state information estimated values are respectively subjected to normalization processing to obtain K first normalized values, wherein K represents a natural number which is greater than or equal to two.

In step S511, a specific manner of the normalization process is a conventional manner, for example, for a first channel state information estimation value x of the K first channel state information estimation values, a corresponding first normalization value may be obtained by calculating according to the following formula

Where maxx denotes a maximum value among the K first channel state information estimation values, and minx denotes a minimum value among the K first channel state information estimation values.

S512, bit digit value quantization processing is carried out on the K first normalization values by the first unmanned machine or the ground station respectively to obtain K first bit strings.

And S513, sequentially combining the K first bit strings by the first unmanned machine or the ground station according to the sending time sequence or the back sending time sequence of the channel detection signal to obtain the first secret key.

Similarly, for the second csi estimate, it is also necessary to perform normalization and quantization in a manner similar to that described in steps S511 to S513, that is, the second drone performs the bit value quantization on the second csi estimate to obtain a second key, which includes but is not limited to: after K second channel state information estimated values are obtained by the second unmanned aerial vehicle based on the channel detection signals sent for K times continuously, firstly, the K second channel state information estimated values are respectively subjected to normalization processing to obtain K second normalized values; then bit digit value quantization processing is carried out on the K second normalization values respectively to obtain K second bit strings; and finally, sequentially combining the K second bit strings according to the sending time sequence or the back sending time sequence of the channel detection signal to obtain the second key.

In the step S5, taking the first csi estimation value as an example, a specific bit value quantization process includes, but is not limited to, the following steps S521 to S523.

S521, a first wireless machine or a ground station divides an amplitude variation interval of the first channel state information estimation value into M amplitude variation subintervals, and performs bit value quantization processing on the amplitude of the first channel state information estimation value according to the following manner: when the amplitude belongs to a certain amplitude variation subinterval among the M amplitude variation subintervals, the quantization value of the amplitude is a preset bit value which corresponds to the certain amplitude variation subinterval and has X bits, wherein M and X respectively represent a natural number which is greater than or equal to two.

In step S521, the first channel state information estimation value is preferably a normalized value (i.e., the first normalized value), for example, the normalized amplitude variation interval will be [0,1], and the following second-order quantization may be performed (i.e., M takes a value of 2): dividing an amplitude change interval [0,1] into a first amplitude change subinterval [0,0.5] and a second amplitude change subinterval (0.5, 1), and presetting a corresponding bit value as 00 (namely X value as 2) for the first amplitude change subinterval [0, 0.5), presetting a corresponding bit value as 11 for the second amplitude change subinterval (0.5, 1), and if the amplitude of the first channel state information estimation value is 0.7, belonging to the second amplitude change subinterval (0.5, 1) and quantizing as a bit string 11.

S522, a first wireless machine or a ground station divides a phase change interval of the first channel state information estimation value into N phase change subintervals, and performs bit value quantization processing on the phase of the first channel state information estimation value as follows: when the phase belongs to a certain phase change subinterval among the N phase change subintervals, the quantized value of the phase is a preset bit value corresponding to the certain phase change subinterval and having the X bits, where N represents a natural number greater than or equal to two.

In step S522, for example, the normalized phase change interval will be [0 ° and 360 ° ], and the following fourth-order quantization may be performed (i.e., N takes a value of 4): the phase change interval [0 °,360 ° ] is divided into a first phase change subinterval [0 °,90 ° ], a second phase change subinterval (90 °,180 ° ]), a third phase change subinterval (180 °,270 ° ] and a fourth phase change subinterval (270 °,360 ° ]), and for the first phase change subinterval [0 °,90 ° ], a corresponding bit value is preset to 00, for the second phase change subinterval (90 °,180 ° ], a corresponding bit value is preset to 01, for the third phase change subinterval (180 °,270 ° ]), a corresponding bit value is preset to 10, for the fourth phase change subinterval (270 °,360 ° ]), a corresponding bit value is preset to 11, and if the phase of the first channel state information estimate is 210 °, the third phase change subinterval (180 °,270 ° ], which can be quantized to a bit string 10.

And S523, performing exclusive OR operation on the result of performing bit numerical quantization on the amplitude of the first channel state information estimation value and the result of performing bit numerical quantization on the phase of the first channel state information estimation value by using a first unmanned machine or a ground station to obtain a first key.

In step S523, if there are K first channel state information estimation values, bit value quantization processing in step S521 needs to be performed on the amplitude of each first channel state information estimation value, and bit strings obtained by quantization are sequentially combined into long bit strings corresponding to the amplitude according to the transmission timing or the retransmission timing of the channel sounding signal, and bit value quantization processing in step S522 needs to be performed on the phase of each first channel state information estimation value, and bit strings obtained by quantization are sequentially combined into long bit strings corresponding to the phases according to the transmission timing or the retransmission timing of the channel sounding signal, and finally, an exclusive or operation is performed on the long bit string corresponding to the amplitude and the long bit string corresponding to the phase, so as to obtain the first key. In addition, similarly, for the second csi estimation value, the second drone needs to use the specific bit value quantization process described in the foregoing steps S521 to S523 to obtain the second key that is theoretically the same as the first key.

S6, carrying out Hash algorithm processing on the first secret key by a first unmanned aerial vehicle or a ground station to obtain a first Hash value, and carrying out Hash algorithm processing on the second secret key by a second unmanned aerial vehicle to obtain a second Hash value.

In step S6, the hash algorithm processing means that the first key and the second key are respectively imported into a conventional hash function to obtain the first hash value and the second hash value. Since the first key and the second key are theoretically the same, it is possible to confirm whether the first key and the second key are the same by performing a hash value interaction between both parties of frequency hopping communication and performing a consistency determination, and if they are the same, it is possible to continue to obtain a corresponding frequency hopping sequence on the corresponding side based on the corresponding key, and if they are different, it is necessary to return to step S2 again.

And S7, transmitting the first hash value on the communication link by a first unmanned machine or a ground station.

And S8, after receiving the first hash value, the second unmanned aerial vehicle judges whether the first hash value is the same as the second hash value, and returns a judgment result.

And S9, after the first unmanned machine or the ground station receives the judgment result, if the judgment result indicates that the first hash value is the same as the second hash value, performing frequency hopping mapping processing on the first key to obtain a first frequency hopping sequence, wherein the first frequency hopping sequence comprises at least one new communication frequency point to be hopped.

In the step S9, if the determination result indicates that the first hash value is the same as the second hash value, it is determined that the first key is the same as the second key, and the first key and the second key can be used as a consensus key for mapping and generating a subsequent frequency hopping sequence to obtain the same frequency hopping sequence, otherwise, the steps S2 to S9 need to be executed again to determine whether the newly obtained first key is the same as the newly obtained second key again. The specific manner of the frequency hopping mapping process may include, but is not limited to, the following two manners: (A) Inputting the first secret key serving as a random number seed into a positive integer generator, and then outputting at least one positive integer as at least one new communication frequency point to be hopped according to input data in a mapping manner by the positive integer generator within a frequency point change range supported by hardware of the first unmanned aerial vehicle or the ground station and the second unmanned aerial vehicle, for example, within a frequency point change range of 1000-6000 MHz and with the resolution of 1MHz, and if 3000 is output within a value range of [1000,6000], taking the frequency point 3000MHz as a new communication frequency point to be hopped; (B) And taking the first key as a random number seed, and generating a random number sequence string in a mapping mode so as to serve as the first frequency hopping sequence. Similarly, when it is determined that the first hash value is the same as the second hash value, the second drone may perform the frequency hopping mapping process on the second key (that is, both frequency hopping communications use the same frequency hopping mapping scheme, for example, use the same positive integer generator), and obtain a second frequency hopping sequence that is the same as the first frequency hopping sequence.

S10, when the first frequency hopping clock reaches the appointed frequency hopping moment, a first unmanned aerial vehicle or a ground station is switched to a new communication frequency point according to the first frequency hopping sequence, so that a new communication link is established with a second unmanned aerial vehicle which is switched to the new communication frequency point according to the second frequency hopping sequence when the second frequency hopping clock reaches the appointed frequency hopping moment.

In the step S10, the hopping time may be, but is not limited to, agreed as follows: after the first frequency hopping sequence is obtained, a frequency point switching instruction is transmitted on the communication link by a first unmanned machine or a ground station, then a second preset time T2 (for example, 10 seconds) after the frequency point switching instruction is transmitted is used as the appointed frequency hopping time by the first unmanned machine or the ground station, and meanwhile, the second preset time T2 after the frequency point switching instruction is received is used as the appointed frequency hopping time, so that a frequency hopping communication party can synchronously switch to the new communication frequency point after transmitting the frequency point switching instruction and waiting for the second preset time T2, a new communication link can be conveniently established with another party, and normal communication can be continuously carried out. And if the new communication link is not established successfully or the new communication link is interrupted, the frequency hopping communication parties respectively count time to a third preset time length T3 (for example, 10 seconds), then the frequency hopping is defaulted to fail, the current communication frequency point is recovered to carry out communication, and then the steps S1-S10 are repeatedly executed, and the frequency hopping communication mechanism is continuously started. In addition, if the first frequency hopping sequence and the second frequency hopping sequence include a plurality of new communication frequency points to be hopped, both the frequency hopping communication parties can respectively switch to each new communication frequency point to be hopped in sequence by using the second preset time length T2 as a frequency hopping period, so as to establish a new communication link with the other party on the corresponding new communication frequency point.

Therefore, based on the frequency hopping communication method of the unmanned aerial vehicle described in the steps S1 to S10, a frequency hopping communication scheme for dynamically generating a common identification frequency hopping sequence based on a channel estimation technology is provided, that is, based on the reciprocity principle of a channel, both frequency hopping communication parties perform channel estimation through interactive channel detection signals respectively to obtain channel state information estimated values in a random complex form, then corresponding channel state information estimated values are subjected to the same bit value quantization processing on both sides to obtain theoretically the same key, then the keys obtained on both sides are subjected to consistency check through the hash value of the interactive key, and finally both parties map according to the common identification key to obtain the same frequency hopping sequence when the consistency check is passed, so that both communication parties of the unmanned aerial vehicle can dynamically generate a frequency hopping sequence without the need of prior agreement between a common ground station (or the unmanned aerial vehicle) and the unmanned aerial vehicle on the premise of not depending on a special frequency hopping system, thereby satisfying the dynamic frequency hopping sequence between different unmanned aerial vehicles and the ground stations, enabling both communication parties to perform communication based on the generated frequency hopping sequence, and being capable of avoiding the limitation of hardware interception of communications, and greatly increasing the security of hardware interception of communications by the frequency hopping.

In addition, on the aspect of the safety of the frequency hopping sequence supported by channel reciprocity, through experimental comparison, in the 5.8GHz frequency band, for a third-party eavesdropper about half a meter away from both sides of frequency hopping communication, the frequency hopping sequence generated 1000 times is only overlapped with the frequency hopping sequence generated by both sides of normal frequency hopping communication for 5 times, and the third-party eavesdropper can only blindly guess the next frequency hopping sequence, so that the method is proved to be safe and reliable. And on the randomness of the hopping sequence supported by coherence time, tested by the NIST (National Institute of Standards and Technology, NIST is a binary sequence generated by a hardware or software based cryptographic random or pseudo random number generator for testing random/arbitrary length) test suite, and 1000 generated hopping sequences all pass the frequency (single bit) test, intra block frequency test, trend test, maximum run detection, binary matrix rank test, spectrum test, non-overlapping word matching test, maurer universal statistics test, linear complexity test, series test, approximate entropy test, accumulation and test, random run variable test, and the like in NIST.

On the basis of the technical solution of the first aspect, the present embodiment further provides a first possible design for performing key consistency check in detail, that is, the following technical solution descriptions are included for the steps S6 to S9.

In step S6, the first drone or the ground station performs hash algorithm processing on the first key to obtain a first hash value, and the second drone performs hash algorithm processing on the second key to obtain a second hash value, including but not limited to the following steps S61 to S62.

S61, the first key is segmented by the first unmanned aerial vehicle or the ground station to obtain Y first key segments, and the second key is segmented by the second unmanned aerial vehicle to obtain Y second key segments, wherein Y represents a natural number greater than or equal to two.

In the step S61, Y may be, for example, 10, and since both sides of the frequency hopping communication use the same segmentation processing method to perform segmentation, the Y first key segments correspond to the Y second key segments one to one.

S62, aiming at each first key segment in the Y first key segments, a first unmanned aerial vehicle or a ground station processes through a Hash algorithm to obtain a corresponding first Hash value, and aiming at each second key segment in the Y second key segments, a second unmanned aerial vehicle processes through the Hash algorithm to obtain a corresponding second Hash value.

In step S7, the first hash value is transmitted by a first drone or ground station over the communication link, including but not limited to: transmitting the Y first hash values corresponding to the Y first key fragments one to one over the communication link.

In step S8, after the second drone receives the first hash value, it determines whether the first hash value is the same as the second hash value, and returns a determination result, which includes but is not limited to: after Y first hash values are received by the second unmanned aerial vehicle, whether the first hash values are the same as corresponding second hash values in the Y second hash values or not is judged according to the Y first hash values, and a judgment result is returned.

In step S9, after the first drone or ground station receives the determination result, if the determination result indicates that the first hash value is the same as the second hash value, performing frequency hopping mapping processing on the first key to obtain a first frequency hopping sequence, which includes but is not limited to: after the first unmanned machine or the ground station receives the judgment result, if the judgment result indicates that Z first hash values are different from the corresponding second hash values, first key segments corresponding to the first hash values in the Z first hash values are removed from the first key to obtain a new first key, then frequency hopping mapping processing is carried out on the new first key to obtain a first frequency hopping sequence, wherein Z represents a natural number smaller than Y, and the first frequency hopping sequence comprises at least one new communication frequency point to be hopped.

Because the first key is theoretically the same as the second key, and the first key and the second key are different in consideration of the influence of factors such as noise and the like, on the premise that the Y first key segments correspond to the Y second key segments one by one, the key segments different from the original second key in the original first key can be removed through the removing process, the same key segments are retained, and the key segments can be used as common identification keys (namely new first keys) for the generation of subsequent frequency hopping sequences, so that the times of returning to the step S2 and obtaining new keys again can be reduced, the time required for generating the frequency hopping sequences is shortened, the success rate of generating the frequency hopping sequences and performing frequency hopping communication is improved, and the influence of factors such as noise and the like is avoided. Similarly, when it is determined that Z second hash values are different from the corresponding first hash values (that is, Z first hash values are different from the corresponding second hash values), the second drone removes, from the second key, second key segments corresponding to Z second hash values, to obtain a new second key, and then performs the frequency hopping mapping process on the new second key to obtain a second frequency hopping sequence that is the same as the first frequency hopping sequence. In addition, the value of Z may be zero, at this time, no key segment is deleted between the two parties, and the first key and the second key are completely the same and may be directly used for the generation of the subsequent frequency hopping sequence; and if Y first hash values are different from the corresponding second hash values, determining that the first key is completely different from the second key, and returning to execute step S2 again, where the second drone may notify the first drone or the ground station to return to execute step S2 by sending a failure signal on the communication link.

Therefore, based on the possible design described in detail in the foregoing steps S6 to S9, the number of times of retrieving a new key can be reduced by confirming key consistency in a segmented manner, the time required for generating a frequency hopping sequence is shortened, the success rate of generating the frequency hopping sequence and performing frequency hopping communication is improved, and the influence of factors such as noise is avoided.

As shown in fig. 2, a second aspect of the present embodiment provides a virtual device for implementing the frequency hopping communication method of the drone, which is possibly designed and executed by a first drone or a ground station in the first aspect, and is disposed in the first drone or the ground station, and includes a first clock synchronization module, a first signal transceiver module, a first channel estimation module, a first quantization processing module, a first hash processing module, a first data transceiver module, a first mapping processing module, and a first frequency hopping execution module;

For the working process, working details, and technical effects of the foregoing apparatus provided in the second aspect of this embodiment, reference may be made to the frequency hopping communication method of the unmanned aerial vehicle in any one of the first aspect or the first aspect, which is not described herein again.

As shown in fig. 3, a third aspect of the present embodiment provides a virtual device for implementing the frequency hopping communication method of the drone, which is performed by a second drone, and is arranged in the second drone, and includes a second clock synchronization module, a second signal transceiver module, a second channel estimation module, a second quantization processing module, a second hash processing module, a second data transceiver module, a second mapping processing module, and a second frequency hopping execution module;

the second frequency hopping execution module is respectively in communication connection with the second clock synchronization module and the second mapping processing module, and is used for switching to a new communication frequency point according to the second frequency hopping sequence when the second frequency hopping clock reaches an appointed frequency hopping time, so as to establish a new communication link with the first unmanned machine or ground station which is switched to the new communication frequency point according to the first frequency hopping sequence when the first frequency hopping clock reaches the appointed frequency hopping time, wherein the first frequency hopping sequence is obtained by performing the frequency hopping mapping processing on the first key when the first unmanned machine or the ground station receives the judgment result and the judgment result indicates that the first hash value is the same as the second hash value, so that the first frequency hopping sequence is the same as the second frequency hopping sequence.

For the working process, working details, and technical effects of the foregoing device provided in the third aspect of this embodiment, reference may be made to the frequency hopping communication method of the unmanned aerial vehicle in the first aspect or any one of the first aspects that may be designed, which is not described herein again.

As shown in fig. 4, a fourth aspect of the present embodiment provides a computer device for executing the drone frequency hopping communication method according to any one of the first aspect or the first aspect and executed by a first drone or a ground station or executed by a second drone, comprising a memory, a processor and a transceiver, which are sequentially connected in communication, wherein the memory is used for storing a computer program, the transceiver is used for transceiving a signal, and the processor is used for reading the computer program and executing the drone frequency hopping communication method according to any one of the first aspect or the first aspect and executed by the first drone or the ground station or executed by the second drone. For example, the Memory may include, but is not limited to, a Random-Access Memory (RAM), a Read-Only Memory (ROM), a Flash Memory (Flash Memory), a First-in First-out (FIFO), and/or a First-in Last-out (FILO), and the like; the transceiver may be, but is not limited to, a WiFi (wireless fidelity) wireless transceiver, a bluetooth wireless transceiver, a GPRS (General Packet Radio Service) wireless transceiver, and/or a ZigBee (ZigBee protocol, low power consumption local area network protocol based on ieee802.15.4 standard) wireless transceiver, etc.; the processor may be, but is not limited to, a microprocessor of the model number STM32F105 family. In addition, the computer device may also include, but is not limited to, a power module, a display screen, and other necessary components.

For the working process, working details, and technical effects of the foregoing computer device provided in the fourth aspect of this embodiment, reference may be made to the frequency hopping communication method for an unmanned aerial vehicle in any one of the first aspect or the first aspect, which is not described herein again.

A fifth aspect of the present embodiments provides a computer readable storage medium storing instructions for a drone frequency hopping communications method as described in any possible design of the first aspect or the first aspect and executed by a first drone or a ground station or by a second drone, i.e., the computer readable storage medium having stored thereon instructions that, when executed on a computer, perform the drone frequency hopping communications method as described in any possible design of the first aspect or the first aspect and executed by the first drone or the ground station or by the second drone. The computer-readable storage medium refers to a carrier for storing data, and may include, but is not limited to, a computer-readable storage medium such as a floppy disk, an optical disk, a hard disk, a flash Memory, a flash disk and/or a Memory Stick (Memory Stick), and the computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices.

For the working process, the working details, and the technical effects of the foregoing computer-readable storage medium provided in the fifth aspect of this embodiment, reference may be made to the first aspect or any one of the first aspects that may be designed for the frequency hopping communication method of the unmanned aerial vehicle, which is not described herein again.

A sixth aspect of the present embodiments provides a computer program product comprising instructions which, when run on a computer, cause the computer to perform a drone frequency hopping communication method as described in the first aspect or any one of the first aspects and performed by a first drone or a ground station or by a second drone. The computer may be a general purpose computer, a special purpose computer, a network of computers, or other programmable devices.

Finally, it should be noted that the present invention is not limited to the above alternative embodiments, and that various other forms of products can be obtained by anyone in light of the present invention. The above detailed description should not be taken as limiting the scope of the invention, which is defined in the claims, and which the description is intended to be interpreted accordingly.

Claims

1. An unmanned aerial vehicle frequency hopping communication method is applied to a first unmanned aerial vehicle or a ground station, and comprises the following steps:

communicating with a second unmanned aerial vehicle on a communication link established based on the current communication frequency point to complete synchronization of a local first frequency hopping clock and a second frequency hopping clock of the second unmanned aerial vehicle;

sending a channel detection signal on the communication link, so that when the second unmanned aerial vehicle receives the channel detection signal, a second channel state information estimation value is obtained through a channel estimation mode, and the channel detection signal is sent back;

when the channel detection signal is received, acquiring a first channel state information estimation value in the channel estimation mode;

carrying out bit number value quantization processing on the first channel state information estimation value to obtain a first key;

performing hash algorithm processing on the first key to obtain a first hash value, which specifically includes: carrying out segmentation processing on the first key to obtain Y first key segments, wherein Y represents a natural number which is greater than or equal to two; processing each first key segment in the Y first key segments through a hash algorithm to obtain a corresponding first hash value;

transmitting Y first hash values corresponding to the Y first key segments one by one on the communication link, so that after the second unmanned aerial vehicle receives the Y first hash values, judging whether the first hash values are the same as corresponding second hash values in the Y second hash values or not for each first hash value in the Y first hash values, and returning a judgment result, wherein the Y second hash values are obtained by the second unmanned aerial vehicle by performing hash algorithm processing on each second key segment in the Y second key segments, the Y second key segments are obtained by the second unmanned aerial vehicle by performing segmentation processing on a second key, and the second key is obtained by the second unmanned aerial vehicle by performing bit value quantization processing on the second channel state information estimation value, so that the Y second hash values correspond to the Y first hash values one by one;

after the judgment result is received, if the judgment result indicates that Z first hash values are different from the corresponding second hash values, eliminating first key segments corresponding to each first hash value in the Z first hash values from the first key to obtain a new first key, and then performing frequency hopping mapping processing on the new first key to obtain a first frequency hopping sequence, wherein Z represents a natural number smaller than Y, and the first frequency hopping sequence comprises at least one new communication frequency point to be hopped;

when the first frequency hopping clock reaches the appointed frequency hopping moment, switching to a new communication frequency point according to the first frequency hopping sequence so as to establish a new communication link with the second unmanned aerial vehicle which is switched to the new communication frequency point according to the second frequency hopping sequence when the second frequency hopping clock reaches the appointed frequency hopping moment, wherein the second frequency hopping sequence is obtained by the second unmanned aerial vehicle performing frequency hopping mapping processing on a new second key, and the new second key is obtained by the second unmanned aerial vehicle after judging that Z second hash values are different from the corresponding first hash values, and second key segments corresponding to the Z second hash values are removed from the second key, so that the second frequency hopping sequence is the same as the first frequency hopping sequence.

2. The unmanned aerial vehicle frequency hopping communication method of claim 1, wherein communicating with a second unmanned aerial vehicle over a communication link established based on a current communication frequency point completes synchronization of a local first frequency hopping clock and a second frequency hopping clock of the second unmanned aerial vehicle, comprising:

sending a frequency hopping starting signal to a second unmanned aerial vehicle on a communication link established based on the current communication frequency point, so that the second unmanned aerial vehicle sends back a corresponding response signal when receiving the frequency hopping starting signal, and the time of a second frequency hopping clock of the second unmanned aerial vehicle is initialized to zero time;

and when the response signal is received, initializing the time of a local first frequency hopping clock to zero time so that the first frequency hopping clock is synchronous with the second frequency hopping clock.

3. The unmanned aerial vehicle frequency hopping communication method of claim 1, wherein performing bit value quantization processing on the first channel state information estimation value to obtain a first key comprises:

after K first channel state information estimated values are obtained based on the channel detection signals which are sent and sent back for K times continuously, normalization processing is carried out on the K first channel state information estimated values respectively to obtain K first normalization values, wherein K represents a natural number which is larger than or equal to two;

respectively carrying out bit digit value quantization processing on the K first normalization values to obtain K first bit strings;

and sequentially combining the K first bit strings according to the sending time sequence or the back sending time sequence of the channel detection signal to obtain the first key.

4. The unmanned aerial vehicle frequency hopping communication method of claim 1, wherein performing bit value quantization processing on the first channel state information estimation value to obtain a first secret key comprises:

dividing the amplitude change interval of the first channel state information estimation value into M amplitude change subintervals, and carrying out bit number value quantization processing on the amplitude of the first channel state information estimation value according to the following mode: when the amplitude belongs to a certain amplitude variation subinterval in the M amplitude variation subintervals, the quantization value of the amplitude is a preset bit value which corresponds to the certain amplitude variation subinterval and has X bits, wherein M and X respectively represent natural numbers which are greater than or equal to two;

dividing the phase change interval of the first channel state information estimation value into N phase change subintervals, and performing bit value quantization processing on the phase of the first channel state information estimation value according to the following mode: when the phase belongs to a certain phase change subinterval in the N phase change subintervals, the quantized value of the phase is a preset bit value which corresponds to the certain phase change subinterval and has the X bits, wherein N represents a natural number which is greater than or equal to two;

and performing exclusive or operation on a result of performing bit numerical quantization on the amplitude of the first channel state information estimation value and a result of performing bit numerical quantization on the phase of the first channel state information estimation value to obtain a first key.

5. An unmanned aerial vehicle frequency hopping communication device is characterized by being arranged in a first unmanned aerial vehicle or a ground station and comprising a first clock synchronization module, a first signal transceiving module, a first channel estimation module, a first quantization processing module, a first hash processing module, a first data transceiving module, a first mapping processing module and a first frequency hopping execution module;

the first hash processing module, communicatively connected to the first quantization processing module, is configured to perform hash algorithm processing on the first key to obtain a first hash value, and specifically includes: carrying out segmentation processing on the first key to obtain Y first key segments, wherein Y represents a natural number which is greater than or equal to two; processing each first key segment in the Y first key segments through a hash algorithm to obtain a corresponding first hash value;

the first data transceiving module is communicatively connected to the first hash processing module, and is configured to transmit, on the communication link, Y first hash values that are one-to-one corresponding to the Y first key segments, so that after the second drone receives the Y first hash values, for each of the Y first hash values, it determines whether the hash value is the same as a corresponding second hash value among the Y second hash values, and returns a determination result, where the Y second hash values are obtained by the second drone performing hash algorithm processing on each of the Y second key segments, the Y second key segments are obtained by the second drone performing the segmentation processing on a second key, and the second key is obtained by the second drone performing bit value quantization processing on the second channel state information estimation value, so that the Y second hash values correspond to the Y first hash values one-to-one;

the first mapping processing module is communicatively connected to the first data transceiver module, and configured to, after receiving the determination result, if the determination result indicates that Z first hash values are different from corresponding second hash values, remove a first key segment corresponding to each of the Z first hash values from the first key to obtain a new first key, and then perform frequency hopping mapping processing on the new first key to obtain a first frequency hopping sequence, where Z represents a natural number smaller than Y, and the first frequency hopping sequence includes at least one new communication frequency point to be hopped;

the first frequency hopping execution module is respectively in communication connection with the first clock synchronization module and the first mapping processing module and is used for switching to a new communication frequency point according to the first frequency hopping sequence when the first frequency hopping clock reaches the appointed frequency hopping time so as to be switched to the second unmanned aerial vehicle on the new communication frequency point according to the second frequency hopping sequence when the second frequency hopping clock reaches the appointed frequency hopping time to establish a new communication link, wherein the second frequency hopping sequence is obtained by the second unmanned aerial vehicle performing frequency hopping mapping processing on a new second key, the new second key is obtained by the second unmanned aerial vehicle after judging that Z second hash values are different from the corresponding first hash values, the second key is obtained after eliminating second key segments corresponding to the second hash values in the Z second hash values, and the second frequency hopping sequence is the same as the first frequency hopping sequence.

6. A computer device, comprising a memory, a processor and a transceiver, which are sequentially connected in communication, wherein the memory is used for storing a computer program, the transceiver is used for transmitting and receiving signals, and the processor is used for reading the computer program and executing the unmanned aerial vehicle frequency hopping communication method according to any one of claims 1 to 4.

7. A computer-readable storage medium having stored thereon instructions which, when executed on a computer, perform the drone frequency hopping communication method of any one of claims 1 to 4.