Differential privacy method and system based on randomly configured reconfigurable intelligent metasurface

Abstract

The present invention relates to the technical field of location privacy protection, and discloses a differential privacy method and system based on a randomly configured reconfigurable intelligent metasurface, including: a single-antenna user sends a positioning request, and a base station responds; the reflection phase shift value of the randomly configured intelligent metasurface is deployed near the base station and set to a working state, so that the direct channel of the measurement signal sent by the base station produces a random phase shift; the channel is superimposed with the direct channel to form a superimposed channel, and the user device obtains the measurement signal, measures its signal strength, and reports it to the base station; the base station obtains the strength of the signal received by the user device and estimates the distance between the user and the base station; the base station sends the obtained user location information to the service provider, and the service provider provides relevant information and services. The present invention can realize the differential privacy solution when the location information is generated, and has the advantages of strong real-time performance, low complexity, and no need for additional algorithm processing.

Description

Technical Field

[0001] The present invention relates to the technical field of location privacy protection, and specifically to a differential privacy method and system based on a randomly configured reconfigurable intelligent metasurface. Background Art

[0002] In base station positioning, the measurement signals sent by the base station to the mobile user end are mainly wireless signals, usually composed of radio frequency signals. These signals are mainly used to measure the signal transmission performance between the mobile user end and the base station to determine the user's location or conduct wireless communication.

[0003] The measurement signal contains the following main information: signal strength, timestamp, frequency information, coding and modulation information, and other related parameters such as signal bandwidth, pulse mode, transmission rate, etc. These parameters help the base station and mobile user end to communicate effectively.

[0004] RSSI (Received Signal Strength Indication) is a measure of the strength of a received wireless signal, expressed in decibel milliwatts (dBm), and represents the ratio of the received signal power to the reference signal power. In base station positioning and wireless communications, RSSI is often used to determine the distance or location between a mobile user terminal and a base station. Summary of the invention

[0005] In view of the above-mentioned problems, the present invention is proposed.

[0006] Therefore, the technical problem solved by the present invention is: how to achieve a differential privacy solution with high real-time performance, low complexity and no need for additional algorithm processing.

[0007] In order to solve the above technical problems, the present invention provides the following technical solutions: a differential privacy method based on randomly configured reconfigurable intelligent metasurface, comprising:

[0008] A single-antenna user sends a positioning request, and the base station responds;

[0009] Deploy the reflection phase shift value DRIS of the randomly configured smart metasurface near the base station and set it to work, so that the direct channel of the measurement signal sent by the base station produces a random phase shift;

[0010] The reflection phase shift value channel of the randomly configured smart metasurface is superimposed with the direct channel to form a superimposed channel. The user equipment obtains the measurement signal, measures its signal strength, and reports it to the base station.

[0011] The base station obtains the strength of the signal received by the user equipment and estimates the distance between the user and the base station;

[0012] The base station will send the obtained user location information after differential privacy processing to the service provider, and the service provider will provide relevant information and services.

[0013] As a preferred solution of the differential privacy method based on randomly configured reconfigurable intelligent metasurface described in the present invention, wherein: the single-antenna user sends a positioning request, including: the user equipment initiates a paging request to find a nearby available base station; after the base station receives the paging request, it establishes a connection with the user equipment, and performs authentication and authorization; the user equipment initiates a positioning request to the base station; the base station contacts at least three nearby base stations with known location information through the user's positioning request, and transmits a measurement signal to the user.

[0014] As a preferred solution of the differential privacy method based on randomly configured reconfigurable intelligent metasurface described in the present invention, wherein: the direct channel of the measurement signal sent by the base station generates a random phase shift including: controlling the electromagnetic response of the DRIS by programming a PIN diode;

[0015] The DRIS controller is used to tune the programming PIN structure to produce a phase shift, which is expressed as:

[0016]

[0017] in, represents the coefficient of DRIS in the pilot estimation stage, Represents the phase shift value randomly generated by each element and changing with time;

[0018] Randomly configure the reflection phase shift of RIS to make DRIS channel;

[0019]

[0020] Among them, h D represents the channel related to DRIS, g represents the channel formed between DRIS and the base station, and g H represents the conjugate transpose of channel g; Represents a vector Diagonalization; h I Indicates the channel formed between DRIS and the user.

[0021] As a preferred solution of the differential privacy method based on randomly configured reconfigurable intelligent metasurface described in the present invention, wherein: the generating of random phase shift includes obtaining h D The channel elements follow the Gaussian distribution The formula is:

[0022]

[0023] According to the law of large numbers and the central limit theorem, when the elements of DRIS are large enough, h D The elements in obey the complex Gaussian distribution, that is, Assuming that the three groups of variables are independent of each other, the formula can be expressed as:

[0024]

[0025] in, represents the mathematical expectation of each channel, Represents the variance of each channel, which can be obtained by measurement and then calculated to obtain δ 2 ;

[0026] Direct Channel d Due to DRIS interference channel h D , a DRIS interference signal is superimposed, causing random changes in the received signal power.

[0027] As a preferred solution of the differential privacy method based on randomly configured reconfigurable intelligent metasurface described in the present invention, wherein: the base station obtains the received signal of the user equipment, including the user equipment obtaining the measurement signal sent by the base station by demodulation;

[0028] The user equipment measures the power of the received signal; due to the interference of DRIS, the signal power measured by the user equipment will produce positive and negative Δp c error;

[0029] The user equipment estimates the signal strength received by the device according to the signal power; the user equipment sends the measured signal strength to the base station.

[0030] As a preferred solution of the differential privacy method based on randomly configured reconfigurable smart metasurface described in the present invention, wherein: the estimating the distance between the user and the base station includes: during the propagation process, the signal attenuates as the propagation distance increases, and the signal propagation distance is calculated according to the signal strength to obtain the relative distance R1 between the user equipment and the base station;

[0031] Since DRIS channel h D For direct channel h d The interference generated causes an error in the signal strength obtained by the base station, resulting in an error ΔR1 in the calculated relative distance R1 between the user equipment and the base station. It can be determined that the user is on a circle with the base station as the center and R1±ΔR1 as the radius;

[0032] When at least three nearby base stations obtain the distances from the user equipment, the user position is obtained at the intersection of multiple circles with the base station as the center and the measured distance as the radius;

[0033] Since the DRIS channel is directly connected to the channel hd The accurate location information obtained is protected, so that the relative position measured by each base station and the user has errors. The base station can only obtain the approximate location range of the user, but cannot obtain the precise location of the user;

[0034]

[0035] in, represents the query function, that is, the function used by the base station to estimate the signal power of the measured signal is recorded as The error generated by the signal strength measured by the base station follows a Gaussian distribution, corresponding to the distribution in the differential privacy Gaussian mechanism. Indicates the signal strength finally measured by the base station under the action of DRIS;

[0036] In the DRIS-based differential privacy scheme, the measurement signals constitute the data set With the dataset The dataset with only one different data is and is the adjacent data set, denoted as and The distance is The function used by the base station to estimate the signal power of the measured signal is recorded as The mapping of Under the action of DRIS, the error of the signal strength measured by the base station obeys the Gaussian distribution, that is,

[0037] As a preferred solution of the differential privacy method based on randomly configured reconfigurable smart metasurface described in the present invention, wherein: the base station sends the obtained user location information processed by differential privacy to the service provider, including that the role of DRIS is that when the non-user party performs differential processing on the data, a random signal similar to noise is generated by the data. Due to the randomness of the signal, the non-user party cannot offset the influence of the random signal through differential processing, so the non-user party cannot obtain accurate data information, thereby realizing the differential privacy solution;

[0038] The base station sends the user location information obtained after differential privacy processing to the service provider. Due to the differential privacy mechanism, the location information received by the service provider already contains random noise, and the user's real location cannot be accurately obtained. It can only provide relevant services within a certain range, thereby protecting user privacy.

[0039] A differential privacy system based on a randomly configured reconfigurable intelligent metasurface using any of the methods described in the present invention, wherein:

[0040] The positioning request and signal transmission module enables the single-antenna user equipment to initiate a positioning request to the base station and send a measurement signal through cooperative communication between the base station and other base stations;

[0041] A smart metasurface configuration module controls the reflection phase shift value of the smart metasurface to achieve differential privacy protection;

[0042] The signal measurement and location estimation module measures the signal strength received by the user equipment and estimates the user's location accordingly;

[0043] The differential privacy protection and data processing module implements differential privacy protection when user location information is generated, ensuring that non-users cannot obtain the user's accurate location.

[0044] A computer device comprises: a memory and a processor; the memory stores a computer program, wherein the processor implements the steps of any one of the methods of the present invention when executing the computer program.

[0045] A computer-readable storage medium stores a computer program, wherein the computer program, when executed by a processor, implements the steps of any one of the methods of the present invention.

[0046] The beneficial effects of the present invention are as follows: by introducing an intelligent metasurface (Reconfigurable Intelligent Surface, RIS) and randomly configuring the reflection phase shift value of the RIS multiple times, it is called a disco RIS (Disco Reconfigurable Intelligent Surface, DRIS); a differential privacy scheme can be implemented when location information is generated, which has the advantages of strong real-time performance, low complexity and no need for additional algorithm processing. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. Among them:

[0048] Figure 1 An overall flow chart of a differential privacy method based on a randomly configured reconfigurable smart metasurface provided in the first embodiment of the present invention;

[0049] Figure 2 A comparison chart of load balancing rates of multiple algorithms under the same task request in a differential privacy method based on a randomly configured reconfigurable intelligent metasurface provided in the second embodiment of the present invention;

[0050] Figure 3 A running time diagram of a differential privacy method based on a randomly configured reconfigurable smart metasurface under different repetition times provided in the second embodiment of the present invention;

[0051] Figure 4 Comparison of load balancing rates of a differential privacy method based on a randomly configured reconfigurable intelligent metasurface under different numbers of tasks provided in the second embodiment of the present invention;

[0052] Figure 5 A comparison of execution costs of a differential privacy method based on a randomly configured reconfigurable intelligent metasurface under different numbers of tasks provided in the second embodiment of the present invention. DETAILED DESCRIPTION

[0053] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the drawings of the specification. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in the art without creative work should fall within the scope of protection of the present invention.

[0054] Example 1

[0055] Reference Figure 1 , as an embodiment of the present invention, provides a differential privacy method based on a randomly configured reconfigurable intelligent metasurface, comprising:

[0056] S1: A single-antenna user sends a positioning request, and the base station responds and collects the information.

[0057] Furthermore, a single-antenna user sends a positioning request, which includes: the user device initiates a paging request to search for nearby available base stations; after receiving the paging request, the base station establishes a connection with the user device and performs authentication and authorization; the user device initiates a positioning request to the base station; the base station contacts other known base stations nearby through the user's positioning request, at least three base stations whose location information is known, and transmits a measurement signal to the user.

[0058] It should be noted that in base station positioning, the measurement signals sent by the base station to the mobile user end are mainly wireless signals, usually composed of radio frequency signals. These signals are mainly used to measure the signal transmission performance between the mobile user end and the base station to determine the user's location or conduct wireless communication.

[0059] S2: Deploy the DRIS near the base station and set it to work, so that the direct channel of the measurement signal sent by the base station generates a random phase shift.

[0060] Furthermore, the direct channel of the measurement signal sent by the base station generates a random phase shift, including controlling the electromagnetic response of the DRIS, such as amplitude, phase shift, polarization, etc., through a simple programmable PIN diode.

[0061] Furthermore, taking the phase response of DRIS as an example, the DRIS controller tunes the programmable PIN junction to produce a phase shift, i.e., a reflection vector, which can be expressed as:

[0062]

[0063] in, represents the coefficient of DRIS in the pilot estimation stage, Represents the phase shift value that is randomly generated by each element and varies with time.

[0064] Furthermore, the reflection phase shift of RIS is randomly configured to make DRIS channel.

[0065]

[0066] Among them, h D represents the channel related to DRIS, g represents the channel formed between DRIS and the base station, and g H represents the conjugate transpose of channel g; Represents a vector Diagonalization; h I Indicates the channel formed between DRIS and the user.

[0067] It should be noted that the measurement signal contains the following main information: signal strength, timestamp, frequency information, coding and modulation information, and other related parameters such as signal bandwidth, pulse mode, transmission rate, etc. These parameters help the base station and mobile user end to communicate effectively.

[0068] S3: The DRIS channel is superimposed on the direct channel to form a superimposed channel. The user equipment obtains the measurement signal, measures its signal strength, and reports it to the base station.

[0069] Furthermore, generating random phase shifts includes obtaining h D The channel elements follow the Gaussian distribution The formula is:

[0070]

[0071]

[0072] Furthermore, according to the law of large numbers and the central limit theorem, when the elements of DRIS are large enough, h D The elements in obey the complex Gaussian distribution, that is, Assuming that the three groups of variables are independent of each other, the formula can be expressed as:

[0073]

[0074] in, represents the mathematical expectation of each channel, Represents the variance of each channel, which can be obtained by measurement and then calculated to obtain δ 2 .

[0075] Furthermore, direct channel h d Due to DRIS interference channel h D , a DRIS interference signal is superimposed, causing random changes in the signal power received from it.

[0076] It should be noted that location information refers to the data of the user's location in space. It includes spatial coordinates and time coordinates, as well as object information related to them, such as identity identification. In the field of the Internet of Things, location information is the basis for realizing service functions, such as smart object positioning and location-based social network services. In addition, location information can also help commercial services or products to conduct precise marketing based on consumers' geographic locations and consumption habits.

[0077] S4: The base station obtains the strength of the signal received by the user equipment and estimates the distance between the user and the base station based on the strength of the signal received by the user equipment.

[0078] Further, setting the working state includes that the user equipment obtains the measurement signal sent by the base station through demodulation.

[0079] Furthermore, the user equipment measures the power of the received signal; due to the interference of DRIS, the signal power measured by the user equipment may produce positive and negative Δpc errors.

[0080] Furthermore, the user equipment calculates RSSI (Received Signal Strength Indication) based on the signal power, which is a measurement value used to represent the strength of the received wireless signal in decibel milliwatts (dBm), indicating the power level of the received signal relative to the reference signal; the user equipment sends the calculated RSSI to the base station.

[0081] Furthermore, estimating the distance between the user and the base station includes that the signal attenuates as the propagation distance increases during the propagation process, so the signal propagation distance can be calculated based on RSSI, thereby obtaining the relative distance R1 between the user equipment and the base station.

[0082] Furthermore, due to the DRIS channel h D For direct channel h dThe interference generated causes a certain error in the RSSI obtained by the base station, which ultimately leads to an error ΔR1 in the calculated relative distance R1 between the user equipment and the base station. It can be determined that the user is on a circle with the base station as the center and R1±ΔR1 as the radius.

[0083] Furthermore, when at least three nearby base stations obtain the distances from the user equipment, the user position can be obtained at the intersection of multiple circles with the base station as the center and the measured distance as the radius.

[0084] Furthermore, due to the DRIS channel to the direct channel h d The accurate location information obtained is protected so that the relative position measured by each base station and the user has a certain error. The base station can only obtain the approximate location range of the user, but cannot obtain the precise location of the user.

[0085]

[0086] in, represents the query function, that is, the function used by the base station to estimate the signal power of the measured signal is recorded as The RSSI error introduced by DRIS follows a Gaussian distribution, corresponding to the distribution in the differential privacy Gaussian mechanism. It indicates the RSSI finally measured by the base station under the action of DRIS.

[0087] Furthermore, in the differential privacy scheme based on DRIS, the measurement signals constitute the data set With the dataset The dataset with only one different data is and is the adjacent data set, denoted as and The distance is The function used by the base station to estimate the signal power of the measured signal is recorded as The mapping of Under the action of DRIS, the error of RSSI measured by the base station obeys Gaussian distribution, that is,

[0088] S5: The base station sends the acquired user location information to the service provider, and the service provider provides relevant information and services.

[0089] Furthermore, the location information includes that the role of DRIS is that when the party intending to query the data performs differential processing on the data, a random noise-like signal will be generated with the data. Due to the randomness of the signal, the influence of the random signal cannot be offset by differential processing, so accurate data information cannot be obtained, and the differential privacy solution cannot be implemented.

[0090] Furthermore, the base station sends the obtained user location information processed with differential privacy to the service provider. Since the smart metasurface introduces random noise, it is impossible to accurately locate the user's location. The base station sends the location information processed with differential privacy to the service provider. The service provider provides services based on the fuzzy location information and cannot accurately obtain the user's real location. It can only provide related services within a certain range, thereby protecting the user's privacy.

[0091] It should be noted that RSSI is an important parameter commonly used in wireless communications, which can be used to evaluate the signal transmission quality and distance between devices. Generally speaking, the higher the RSSI value, the stronger the received signal strength, the closer the distance between devices, or the better the signal transmission quality; conversely, the lower the RSSI value, the weaker the signal strength, the farther the distance between devices, or the worse the signal transmission quality. In base station positioning and wireless communications, RSSI is often used to determine the distance or position between a mobile user terminal and a base station.

[0092] On the other hand, this embodiment also provides a differential privacy system based on a randomly configured reconfigurable smart metasurface, which includes:

[0093] The positioning request and signal transmission module enables the single-antenna user equipment to initiate a positioning request to the base station and send a measurement signal through cooperative communication between the base station and other base stations.

[0094] The smart metasurface configuration module controls the reflection phase shift value of the smart metasurface to achieve differential privacy protection.

[0095] The signal measurement and location estimation module measures the signal strength received by the user equipment and estimates the user's location accordingly.

[0096] The differential privacy protection and data processing module implements differential privacy protection when user location information is generated, ensuring that non-users cannot obtain the user's accurate location.

[0097] If the above functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc., which can store program codes.

[0098] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in conjunction with such instruction execution systems, devices or apparatuses. For the purposes of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in conjunction with such instruction execution systems, devices or apparatuses.

[0099] More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection with one or more wires (electronic device), a portable computer disk case (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be a paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, deciphering or, if necessary, processing in another suitable manner, and then stored in a computer memory.

[0100] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, a plurality of steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0101] Example 2

[0102] Reference Figure 2-5 , is an embodiment of the present invention, which provides a differential privacy method based on a randomly configured reconfigurable intelligent metasurface. In order to verify the beneficial effects of the present invention, scientific demonstration is carried out through economic benefit calculation and simulation experiments.

[0103] Figure 2 It shows that after receiving the location request initiated by the legitimate user, the base station sends a measurement signal to the legitimate user. The direct channel h of the measurement signal d Under the action of DRIS deployed near the BS, random phase shift is generated to form a DRIS channel Direct Channel d It is superimposed with the DRIS channel to form a superimposed channel h L =h d +h D Figure 3 Description: The base station uses the principle of triangulation. Three base stations near the user send measurement signals to the user respectively, and obtain three relative distances to determine the user's information. Without DRIS interference, the base station can accurately obtain the user's location information through triangulation without considering the influence of system errors. Under the influence of DRIS interference, the measurements of the three base stations A, B, and C correspond to ±ΔR A , ±ΔR B , ±ΔR C The error makes the user position actually obtained by the base station only determined within a range near the actual position of the user. By adjusting the reflection phase shift configured by RIS, the accuracy of the position range obtained by the base station can be adjusted.

[0104] Consider the following application example: three base stations BS1, BS2 and BS3 are deployed at (-150m, 0m, 5m), (150m, 0m, 5m) and (0m, 150m, 5m) respectively; users are randomly and evenly distributed in a circular area with a center of (0m, 0m, 0m) and a radius of 20m; at the same time, a DRIS with a unit number of ND is deployed near BS3, that is, (0m, 148m, 3m).

[0105] In particular, DRIS uses 1-bit phase quantization accuracy, that is, its possible phase values ​​are And the probability of obtaining them is and First, consider that the number of DRIS units is 1024, and the square of the difference between the user position and the position obtained by the RSSI method under the DRIS differential privacy scheme designed by the present invention is The value of the number of occurrences / total number of times corresponding to it is Figure 4 Given in.

[0106] further, Figure 5 The protection results of the differential privacy scheme proposed in the present invention under different numbers of DRIS elements are given in . It can be seen that the user's location error result can be adjusted by using different numbers of units. Therefore, in practical applications, the required differential privacy effect can be achieved by using DRIS with different numbers of units according to user needs.

[0107] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A differential privacy method based on randomly configured reconfigurable smart metasurface, characterized in that: include: A single-antenna user sends a positioning request, and the base station responds; Deploy the reflection phase shift value DRIS of the randomly configured smart metasurface near the base station and set it to work, so that the direct channel of the measurement signal sent by the base station produces a random phase shift; The reflection phase shift value channel of the randomly configured smart metasurface is superimposed with the direct channel to form a superimposed channel. The user equipment obtains the measurement signal, measures its signal strength, and reports it to the base station. The base station obtains the strength of the signal received by the user equipment and estimates the distance between the user and the base station; The base station will send the obtained user location information after differential privacy processing to the service provider, and the service provider will provide relevant information and services.

2. The differential privacy method based on randomly configured reconfigurable intelligent metasurface according to claim 1, characterized in that: The single-antenna user sending a positioning request includes the user equipment initiating a paging request to find a nearby available base station; After receiving the paging request, the base station establishes a connection with the user equipment and performs authentication and authorization; The user equipment initiates a positioning request to the base station; the base station contacts at least three nearby base stations with known location information through the user's positioning request, and transmits a measurement signal to the user.

3. The differential privacy method based on randomly configured reconfigurable intelligent metasurface according to claim 2, characterized in that: The direct channel of the measurement signal sent by the base station generates a random phase shift including: controlling the electromagnetic response of the DRIS by programming a PIN diode; Use the DRIS controller to tune the PIN structure to generate phase shifts; randomly configure the reflection phase shift of the RIS so that the DRIS channel satisfies: in, represents the coefficient of DRIS in the pilot estimation stage, h D represents the channel related to DRIS, g represents the channel formed between DRIS and the base station, and g H represents the conjugate transpose of channel g; Represents a vector Diagonalization; h I Indicates the channel formed between DRIS and the user.

4. The differential privacy method based on randomly configured reconfigurable intelligent metasurface according to claim 3, characterized in that: The generating of random phase shift includes obtaining h D The channel elements follow the Gaussian distribution The formula is: Direct Channel d Due to DRIS interference channel h D , a DRIS interference signal is superimposed, causing random changes in the received signal power.

5. The differential privacy method based on randomly configured reconfigurable intelligent metasurface according to claim 4, characterized in that: The base station obtaining the user equipment received signal includes the user equipment obtaining the measurement signal sent by the base station through demodulation; The user equipment measures the power of the received signal; due to the interference of DRIS, the signal power measured by the user equipment will produce positive and negative Δp c error; The user equipment estimates the signal strength received by the device according to the signal power; the user equipment sends the measured signal strength to the base station.

6. The differential privacy method based on randomly configured reconfigurable intelligent metasurface according to claim 5, characterized in that: The estimating the distance between the user and the base station includes calculating the distance of signal propagation according to the signal strength, as the signal attenuates during propagation as the propagation distance increases, to obtain the relative distance R1 between the user equipment and the base station; Since DRIS channel h D For direct channel h d The interference generated causes an error in the signal strength obtained by the base station, resulting in an error ΔR1 in the calculated relative distance R1 between the user equipment and the base station. It can be determined that the user is on a circle with the base station as the center and R1±ΔR1 as the radius; When at least three nearby base stations obtain the distances from the user equipment, the user position is obtained at the intersection of multiple circles with the base station as the center and the measured distance as the radius; Since the DRIS channel is directly connected to the channel h d The accurate location information obtained is protected, so that the relative position measured by each base station and the user has errors. The base station can only obtain the approximate location range of the user, but cannot obtain the user's precise location; in, represents the query function, that is, the function used by the base station to estimate the signal power of the measured signal is recorded as The error generated by the signal strength measured by the base station follows a Gaussian distribution, corresponding to the distribution in the differential privacy Gaussian mechanism. Indicates the signal strength finally measured by the base station under the action of DRIS; In the DRIS-based differential privacy scheme, the measurement signals constitute the data set With the dataset The dataset with only one different data is and is the adjacent data set, denoted as and The distance is The function used by the base station to estimate the signal power of the measured signal is recorded as The mapping of Under the action of DRIS, the error of the signal strength measured by the base station obeys the Gaussian distribution, that is, 7. The differential privacy method based on randomly configured reconfigurable intelligent metasurface according to claim 6, characterized in that: The base station sends the obtained user location information after differential privacy processing to the service provider. The function of DRIS is that when the non-user party performs differential processing on the data, a random signal similar to noise is generated by the data. Due to the randomness of the signal, the non-user party cannot offset the influence of the random signal through differential processing, so the non-user party cannot obtain accurate data information, avoid privacy data leakage, and realize the differential privacy solution; The base station sends the user location information obtained after differential privacy processing to the service provider. Due to the differential privacy mechanism, the location information received by the service provider already contains random noise, and the user's real location cannot be accurately obtained. It can only provide relevant services within a certain range, thereby protecting user privacy.

8. A differential privacy system based on a randomly configured reconfigurable smart metasurface using the method according to any one of claims 1 to 7, comprising: The positioning request and signal transmission module enables the single-antenna user equipment to initiate a positioning request to the base station and send a measurement signal through cooperative communication between the base station and other base stations; A smart metasurface configuration module controls the reflection phase shift value of the smart metasurface to achieve differential privacy protection; The signal measurement and location estimation module measures the signal strength received by the user equipment and estimates the user's location accordingly; The differential privacy protection and data processing module implements differential privacy protection when user location information is generated, ensuring that non-users cannot obtain the user's accurate location.

9. A computer device comprising: A memory and a processor; the memory stores a computer program, characterized in that: when the processor executes the computer program, the steps of the differential privacy method based on a randomly configured reconfigurable intelligent metasurface as described in any one of claims 1-7 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the differential privacy method based on a randomly configured reconfigurable smart metasurface as described in any one of claims 1 to 7 are implemented.

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