Positioning system based on assistance of double intelligent reflecting surfaces

Abstract

The invention relates to the field of intelligent reflecting surface auxiliary positioning, in particular to a positioning system based on double intelligent reflecting surface assistance. According to the scheme, multiple sets of beam forming codes are randomly set for the two intelligent reflecting surfaces, a signal processor measures a measurement sample value corresponding to each set of beam forming codes, a phase shift processor gives an optimization suggestion for each reflecting unit on the two intelligent reflecting surfaces according to the measurement sample values and the corresponding beam forming codes, and the beam forming codes on the two intelligent reflecting surfaces are optimized according to the optimization suggestion. Meanwhile, the position coordinates of the two intelligent reflecting surfaces are sent to a positioner; the two corresponding phase shift controllers form corresponding beamforming codes according to the optimization suggestions and configure the beamforming codes on the corresponding intelligent reflecting surfaces, the receiver sends own position coordinates to the positioner, and the positioner determines the position of each reflecting unit of the two intelligent reflecting surfaces according to the optimization suggestions of each reflecting unit of the two intelligent reflecting surfaces, the position coordinates of the two intelligent reflecting surfaces and the position coordinates of the receiver. And the position of the unknown transmitter is determined, and position information is fed back to the receiver. The method is suitable for high-precision positioning.

Description

Technical Field

[0001] The invention relates to the field of intelligent reflective surface assisted positioning, and in particular to a positioning system based on the assistance of double intelligent reflective surfaces. Background Art

[0002] Most existing studies assume that the core network can obtain all the information about the channel from the transmitter to the smart reflector surface and the channel from the smart reflector surface to the receiver when optimizing the smart reflector surface. However, this assumption lacks realistic considerations: 1) The large-scale deployment of base stations makes the channel conditions in real communication scenarios very complicated; 2) The physical distance between each reflector unit on the smart reflector surface is close, resulting in the channel states of reflections passing through different reflector units being close, which increases the difficulty of accurately estimating the states of each channel; 3) In order to obtain the channel information from the transmitter to the smart reflector surface and from the smart reflector surface to the receiver, the existing channel estimation strategy requires the smart reflector surface to feedback the received pilot signal in real time, which requires an independent information transmission link between the smart reflector surface and the base station, and the smart reflector surface must also have signal reception and processing functions. However, the current network protocol architecture does not support these settings; 4) Even if information interaction is allowed between the smart reflector surface and the base station, this will increase the construction cost of the smart transmitting surface and the network energy consumption, making it difficult to deploy the smart reflector surface on a large scale.

[0003] Although the application of smart reflectors in wireless communications has been widely studied and has shown significant communication gains, existing research has mainly focused on optimizing smart reflectors to enhance communication performance, while less attention has been paid to their potential in wireless positioning. Traditional wireless positioning technologies usually rely on base stations to measure information such as arrival time, arrival angle, or received signal strength, but in complex environments (such as non-line-of-sight NLOS scenarios), signal fading and multipath effects seriously affect positioning accuracy.

[0004] Although smart reflective surfaces have the ability to flexibly control wireless signals and can theoretically be used to improve positioning performance, existing research on smart reflective surfaces has hardly touched upon how to use smart reflective surfaces for precise positioning. In addition, the current mainstream smart reflective surface configuration methods are often based on known channel state information, and in the case of unknown channels, there is still a lack of research on how to use smart reflective surfaces to achieve high-precision positioning. Summary of the invention

[0005] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a positioning system based on the assistance of dual intelligent reflective surfaces, which realizes high-precision positioning based on the cooperation of two intelligent reflective surfaces and the assistance of intelligent reflective surfaces without any channel information.

[0006] The present invention adopts the following technical scheme to achieve the above-mentioned purpose. The present invention provides a positioning system based on dual intelligent reflective surfaces, including a transmitter, a receiver, a coordinator, a signal processor, a phase shift processor, two phase shift controllers, two intelligent reflective surfaces, and a locator; The coordinator sends an indication signal to the phase shift processor, indicating the start of the sampling phase of the smart reflective surface. In the sampling phase, multiple groups of beamforming codes are randomly set for the two smart reflective surfaces, and the signal processor measures the measurement sample values ​​corresponding to each group of beamforming codes. According to the measurement sample values ​​and the corresponding beamforming codes, the phase shift processor gives optimization suggestions for each reflection unit on the two smart reflective surfaces, and sends them to the two corresponding phase shift controllers and locators, and at the same time sends the position coordinates of the two smart reflective surfaces to the locator; Two corresponding phase shift controllers form corresponding beamforming codes according to the optimization suggestions and are configured on the corresponding intelligent reflection surfaces. The receiver sends its own position coordinates to the locator. The locator determines the position of the unknown transmitter based on the optimization suggestions of each reflection unit of the two intelligent reflection surfaces, the position coordinates of the two intelligent reflection surfaces and the position coordinates of the receiver, and feeds the position information back to the receiver.

[0007] Furthermore, in the sampling stage, the beamforming of each reflection unit of the two intelligent reflection surfaces is randomly generated according to a uniform distribution, and the generation mode is an advance generation mode or an immediate generation mode.

[0008] Furthermore, the advance generation mode means that the random beamforming is generated in advance before the module is deployed in the network and stored in the corresponding storage element. According to the generation position, the advance generation mode is divided into phase shift controller generation and phase shift processor generation; Phase shift controller generation means that each phase shift controller generates multiple sets of random beamforming and a set of codebooks in advance. After being deployed in the network, the phase shift processor obtains the beamforming used by all smart reflectors by setting an interactive mode; Phase shift processor generation means that the phase shift processor generates multiple groups of random beamforming and a set of codebooks in advance. After being deployed in the network, the phase shift processor sends the random beamforming and codebooks to all phase shift controllers by setting an interactive mode.

[0009] Furthermore, the instant generation mode refers to the instant generation of random beamforming in the sampling phase, which reduces storage overhead by increasing computational overhead. According to the generation position, the instant generation mode is divided into phase shift controller generation and phase shift processor generation. Phase shift controller generation means that each phase shift controller generates random beamforming in real time according to its own codebook, and the phase shift processor obtains the beamforming adopted by all smart reflectors during the sampling process by setting an interactive mode; The phase shift processor generates random beamforming according to its own codebook in real time, and the phase shift processor sends the beamforming to all phase shift controllers during the sampling process by setting an interactive mode.

[0010] Furthermore, the phase shift processor provides optimization suggestions for each reflection unit on the two smart reflection surfaces, including: The phase shift processor provides optimization suggestions for each reflection unit on the two smart reflection surfaces according to the communication improvement algorithm, and the communication improvement algorithm specifically includes: The phase shift controller forms a random beamforming codebook Each time the phase shift controller generates a beamforming code, the transmitter sends a signal with the same power to the receiver, and the signal processor measures the sample data. , and finally the signal processor will obtain the corresponding Sample data , for the Each reflective unit of the smart reflective surface is controlled by a phase shift processor. The phase shift that maximizes the expected conditional sample is selected from the feasible phase shifts as the phase shift value of the reflection unit, that is: ; in represents the phase shift value corresponding to the maximum expected value, and n represents the The nth reflection unit of the smart reflection surface, Indicates A possible phase shift, , represents the number of possible phase shifts per unit, represents the phase shift set, For one dimensional vector, whose components correspond to the The phase shift of a reflective unit of a smart reflective surface, Indicates all The measurement samples satisfy If there are multiple phase shift values ​​that maximize the conditional sample expectation, then any one is selected.

[0011] Furthermore, the locator determines the location of the unknown transmitter by: The locator determines the position of the unknown transmitter according to the dual intelligent reflector positioning algorithm; the dual intelligent reflector positioning algorithm specifically includes: Smart reflective surface has Reflection unit, A planar array of For along The number of reflection units in the axial direction, For along The number of reflection units in the axial direction, The reflection unit is in the On the smart reflective surface Row, No. The reflection unit of the column, is the direct channel from transmitter to receiver, For the The reflection channel introduced by the reflection unit, is the phase difference between the direct channel and the reflected channel. According to the properties of the line-of-sight channel, for the Two adjacent reflection units on the same row of a smart reflection surface as well as ,but: ; For Two adjacent reflective units on the same row of a smart reflective surface as well as ,but: ; is the wavelength of the carrier used to transmit the signal, is the distance between two adjacent reflection units, The transmitter arrives at The vertical angle of arrival of the first intelligent reflective surface, The vertical departure angle of the smart reflector from the receiver to the transmitter to the The horizontal arrival angle of the first smart reflector, The horizontal departure angle from the smart reflector to the receiver; Optimize the reflection unit of the smart reflective surface As a pair An optimal estimate based on random samples ,Right now , the locator will be based on as well as Let's first estimate and ,according to and The relationship between When there are reflection units, we get Independent estimates of: ,in , Express Independent estimates of Take the average of all independent estimates as the pair The final estimate of: ; For The number of independent estimates of Express The final estimate of Based on The final estimate of and The relationship between When the reflection unit Independent estimates of: , Express Independent estimates of Take the average of all independent estimates as the pair The final estimate of: , For The number of independent estimates of Express The final estimate of Finally, based on the two known coordinates of the smart reflector and the estimated arrival angle from the transmitter to the smart reflector , draw two rays, and the coordinates of the intersection of the two rays are the final estimate of the unknown transmitter position.

[0012] The beneficial effects of the present invention are: Compared with the traditional technology of optimizing the intelligent reflective surface based on channel state information to improve the communication quality, the present invention proposes a joint communication enhancement and positioning technology that does not require any channel information. This technology achieves signal enhancement by cleverly designing a channel-free blind beamforming scheme for the intelligent reflective surface. At the same time, it realizes the positioning of unknown targets by analyzing the spatial information carried in the reflected signal of the intelligent reflective surface that can be used for target positioning. This innovation breaks through the traditional method's reliance on accurate channel state information estimation, avoids the computational complexity and overhead of high-dimensional channel state information estimation, and enables the intelligent reflective surface to effectively improve communication performance in an unknown channel environment and simultaneously achieve high-precision positioning, thereby giving the intelligent reflective surface stronger environmental adaptability and a wider range of application scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a structural block diagram of a positioning system based on dual intelligent reflective surface assistance provided by an embodiment of the present invention; Figure 2 is a schematic diagram of the angle of arrival and the angle of departure provided by an embodiment of the present invention; Figure 3It is a schematic diagram of dual intelligent reflective surface positioning provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0014] To make the purpose, technical solution and advantages of the embodiments of the present invention more clear, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0015] The present invention provides a positioning system based on dual intelligent reflective surfaces. Figure 1 As shown, it includes a transmitter, a receiver, a coordinator, a signal processor, a phase shift processor, a first phase shift controller, a second phase shift controller, a first smart reflective surface, a second smart reflective surface, and a locator.

[0016] The coordinator sends an indication signal to the phase shift processor, indicating the start of the sampling phase of the smart reflector. In the sampling phase, multiple groups of beamforming codes are randomly set for the two smart reflectors (i.e., the first smart reflector and the second smart reflector), and the signal processor measures the measurement sample value corresponding to each group of beamforming codes, i.e., the signal strength; According to the measured sample values ​​and the corresponding beamforming codes, the phase shift processor calculates the optimization suggestions for each reflection unit on the two intelligent reflection surfaces according to the communication improvement algorithm, and sends them to the corresponding two phase shift controllers (i.e., the first phase shift controller and the second phase shift controller) and the positioner; Two phase shift controllers form corresponding beamforming codes according to the optimization suggestions and are configured on corresponding smart reflective surfaces; The phase shift processor sends the position coordinates of the two intelligent reflective surfaces to the locator; The phase shift processor sends a feedback signal to the coordinator, indicating that the intelligent reflector beamforming has been optimized; The coordinator sends an indication signal to the receiver, indicating that the receiver sends its own position coordinates to the locator; after the receiver has finished sending, it sends a feedback signal to the coordinator, indicating that the receiver's position coordinates have been sent; The coordinator sends an indication signal to the locator, indicating the start of locating the unknown transmitter; According to the optimization suggestions of each reflection unit of the two intelligent reflection surfaces, the position coordinates of the two intelligent reflection surfaces and the position coordinates of the receiver, the locator calculates the position of the position transmitter according to the positioning algorithm and sends it to the receiver; The locator sends a feedback signal to the coordinator, indicating that the positioning of the unknown transmitter has been completed.

[0017] Specifically, in the sampling phase, the beamforming (ie, phase shift) of each reflection unit of each intelligent reflection surface is randomly generated according to a uniform distribution. The generation method can be two modes: advance generation or instant generation.

[0018] Generate the schema ahead of time: This mode means that the random beamforming is generated in advance before the module is deployed in the network (for example, when it leaves the factory) and stored in the corresponding storage element. According to the generation location, the advance generation mode is divided into two methods: phase shift controller generation and phase shift processor generation.

[0019] Phase shift controller generation: Each phase shift controller generates multiple sets of random beamforming and a set of codebooks in advance. After being deployed in the network, the phase shift processor obtains the beamforming used by all smart reflectors through a certain interactive method.

[0020] Phase shift processor generation: The phase shift processor generates multiple sets of random beamforming and a set of codebooks in advance. After being deployed in the network, the phase shift processor sends the random beamforming and codebooks to all phase shift controllers through a certain interactive method.

[0021] Instant Generation Mode: This mode means that random beamforming is generated by the module in real time during the sampling phase, which reduces storage overhead by increasing computational overhead. According to the generation location, the real-time generation mode is divided into two methods: phase shift controller generation and phase shift processor generation.

[0022] Phase shift controller generation: Each phase shift controller generates random beamforming in real time according to its own codebook, and the phase shift processor obtains the beamforming adopted by all smart reflectors during the sampling process through a certain interactive method.

[0023] Phase shift processor generation: The phase shift processor generates random beamforming in real time according to its own codebook. The phase shift processor sends the beamforming to all phase shift controllers during the sampling process through a certain interactive method.

[0024] The dual intelligent reflector communication enhancement algorithm specifically includes: Consider a SISO network assisted by two smart reflectors, each containing reflection units. The phase shift value of each reflection unit is taken from the discrete set , .

[0025] First, the phase shift controller forms a random beamforming codebook Beamforming Coding Each time the phase shift controller generates a beamforming code, the transmitter sends a signal of the same power to the receiver, and the signal processor measures the sample data. Finally, the signal processor will get the corresponding Sample data For the Each reflective unit of the smart reflective surface is controlled by a phase shift processor. Among the feasible phase shifts, the phase shift that maximizes the expected conditional sample is selected as the phase shift value of the reflection unit, that is, ; in represents the phase shift value corresponding to the maximum expected value, and n represents the The nth reflection unit of the smart reflection surface, Indicates A possible phase shift, , represents the number of possible phase shifts per unit, represents the phase shift set, For one dimensional vector, whose components correspond to the The phase shift of a reflective unit of a smart reflective surface, Indicates all The measurement samples satisfy If there are multiple phase shift values ​​that maximize the conditional sample expectation, then any one is selected.

[0026] After the phase shift processor determines the phase shift of all reflective units according to the above method, it sends the optimization suggestion to the two phase shift controllers, and the phase shift controllers adjust the reflection phase shift of the corresponding smart reflective surface according to the optimization suggestion. Subsequently, the phase shift processor sends the optimization suggestion and the position coordinates of the two smart reflective surfaces to the locator, and feeds back the optimization completion information to the coordinator. After receiving the information feedback, the coordinator starts to instruct the locator to start locating the unknown transmitter.

[0027] For details, refer to the following embodiments.

[0028] Consider a single-user network assisted by two smart reflectors, each of which contains two reflector units and each reflector unit has two feasible phase shifts: , each time a smart reflective surface is optimized, the sample is taken 6 times, that is, . Six groups of beamforming are randomly generated, and the test sample sets obtained are shown in Table 1: Test sample set Table 1 For the first reflection unit of the first smart reflection surface, when its phase shift is 0, corresponding to the 1st, 2nd, and 6th sampling, the conditional sample expectation is: The following Table 2 can be calculated similarly.

[0029] Reflection unit and phase shift data table 2 According to the above calculation results, the phase shift processor optimizes the phase shift of the four reflection units of the two reflection surfaces through the phase shift controller to .

[0030] The dual intelligent reflective surface positioning algorithm specifically includes: After receiving the feedback signal from the phase shift processor that the beamforming optimization is completed, the coordinator immediately sends an instruction signal to the locator, indicating that the unknown transmitter should be located. After receiving the phase shift optimization suggestions of the two smart reflectors sent by the phase shift processor, the position coordinates of the two smart reflectors, and the position coordinates of the receiver itself, the locator starts to locate the unknown transmitter according to the instruction signal from the coordinator.

[0031] You can set the smart reflective surface parallel to Flat placement with The smart reflective surface is usually manufactured as A planar array of For along The number of reflection units in the axial direction (the number of units in each row), For along The number of reflection units (rows) in the axial direction. The reflection unit is in the On the smart reflective surface Row, No. The reflection unit of the column. is the direct channel from the transmitter to the receiver, t is the transmitter, which means the transmitter, r is the receiver, which means the receiver, and For the The reflection channel introduced by the reflection unit. Since both the direct channel and the reflection channel are complex numbers, is the phase difference between the direct channel and the reflected channel. Since the direct channel and the reflected channel are usually line-of-sight channels, according to the properties of the line-of-sight channel, we can obtain that for the Two adjacent reflection units on the same row of a smart reflection surface as well as , then the present invention has Similarly, for Two adjacent reflective units on the same row of a smart reflective surface as well as The present invention has In the above two equations, is the wavelength of the carrier used to transmit the signal, is the distance between two adjacent reflection units, The transmitter arrives at The vertical angle of arrival of the first intelligent reflective surface, The vertical departure angle of the smart reflector from the receiver to the transmitter to the The horizontal arrival angle of the first smart reflector, The horizontal departure angle of the intelligent reflector from the receiver. For specific angle information, please refer to Figure 2 , Figure 2 Here m stands for meter (unit: meter).

[0032] Furthermore, the present invention proves that the optimization suggestion of the intelligent reflector unit obtained in the aforementioned communication improvement algorithm Can be regarded as An optimal estimate based on random samples is denoted as Since both smart reflectors and the receiver feed back their own position coordinates to the locator, as well as It can be calculated by the corresponding position coordinates. The locator will be based on as well as Let's first estimate and According to the above and The relationship between When there are multiple reflection units, the present invention can obtain a pair of Independent estimates of: in The present invention can have at most Pair Therefore, the present invention finally takes the average value of all these independent estimates as the The final estimate of: Similarly, based on The final estimated value of and The relationship between When one reflection unit is Independent estimates of: The present invention can obtain at most Pair The average of these independent estimates is taken as the The final estimate of: In got After the estimation, the locator will finally complete the positioning of the transmitter. For simplicity, the present invention only considers the estimation of the transmitter at The method of locating the transmitter by the locator is very simple: Figure 3 As shown, based on the two known coordinates of the smart reflector and the estimated arrival angle from the transmitter to the smart reflector The present invention can draw two rays, and the coordinates of the intersection of the two rays are the final estimation of the transmitter position. After the estimation of the transmitter position is completed, the locator feeds back the estimated position to the receiver and sends a feedback signal to the coordinator to indicate that the positioning algorithm has been completed.

[0033] The above is only a preferred embodiment of the present invention. It should be understood that the present invention is not limited to the form disclosed herein, and should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the concept described herein through the above teachings or the technology or knowledge of the relevant field. The changes and modifications made by those skilled in the art shall not deviate from the spirit and scope of the present invention, and shall be within the scope of protection of the claims attached to the present invention.

Claims

1. A positioning system based on dual intelligent reflective surfaces, characterized in that: It includes a transmitter, a receiver, a coordinator, a signal processor, a phase shift processor, two phase shift controllers, two intelligent reflective surfaces, and a positioner; The coordinator sends an indication signal to the phase shift processor, indicating the start of the sampling phase of the smart reflective surface. In the sampling phase, multiple groups of beamforming codes are randomly set for the two smart reflective surfaces, and the signal processor measures the measurement sample values ​​corresponding to each group of beamforming codes. According to the measurement sample values ​​and the corresponding beamforming codes, the phase shift processor gives optimization suggestions for each reflection unit on the two smart reflective surfaces, and sends them to the two corresponding phase shift controllers and locators, and at the same time sends the position coordinates of the two smart reflective surfaces to the locator; Two corresponding phase shift controllers form corresponding beamforming codes according to the optimization suggestions and are configured on the corresponding intelligent reflection surfaces. The receiver sends its own position coordinates to the locator. The locator determines the position of the unknown transmitter based on the optimization suggestions of each reflection unit of the two intelligent reflection surfaces, the position coordinates of the two intelligent reflection surfaces and the position coordinates of the receiver, and feeds the position information back to the receiver.

2. The dual intelligent reflective surface-assisted positioning system according to claim 1, characterized in that: In the sampling stage, the beamforming of each reflection unit of the two intelligent reflection surfaces is randomly generated according to a uniform distribution, and the generation mode is an advance generation mode or an instant generation mode.

3. The dual intelligent reflective surface-assisted positioning system according to claim 2, characterized in that: The advance generation mode means that the random beamforming is generated in advance before the module is deployed in the network and stored in the corresponding storage element. According to the generation position, the advance generation mode is divided into phase shift controller generation and phase shift processor generation; Phase shift controller generation means that each phase shift controller generates multiple sets of random beamforming and a set of codebooks in advance. After being deployed in the network, the phase shift processor obtains the beamforming used by all smart reflectors by setting an interactive mode; Phase shift processor generation means that the phase shift processor generates multiple groups of random beamforming and a set of codebooks in advance. After being deployed in the network, the phase shift processor sends the random beamforming and codebooks to all phase shift controllers by setting an interactive mode.

4. The positioning system based on dual intelligent reflective surfaces as claimed in claim 2, characterized in that: The instant generation mode refers to the instant generation of random beamforming in the sampling stage, which reduces the storage overhead by increasing the calculation overhead. According to the generation position, the instant generation mode is divided into phase shift controller generation and phase shift processor generation; Phase shift controller generation means that each phase shift controller generates random beamforming in real time according to its own codebook, and the phase shift processor obtains the beamforming adopted by all smart reflectors during the sampling process by setting an interactive mode; The phase shift processor generates random beamforming according to its own codebook in real time, and the phase shift processor sends the beamforming to all phase shift controllers during the sampling process by setting an interactive mode.

5. The dual intelligent reflective surface-assisted positioning system according to claim 1, characterized in that: The phase shift processor provides optimization suggestions for each reflective unit on the two smart reflective surfaces, including: The phase shift processor provides optimization suggestions for each reflection unit on the two smart reflection surfaces according to the communication improvement algorithm, and the communication improvement algorithm specifically includes: The phase shift controller forms a random beamforming codebook Each time the phase shift controller generates a beamforming code, the transmitter sends a signal with the same power to the receiver, and the signal processor measures the sample data. , and finally the signal processor will obtain the corresponding Sample data , for the Each reflective unit of the smart reflective surface is controlled by a phase shift processor. The phase shift that maximizes the expected conditional sample is selected from the feasible phase shifts as the phase shift value of the reflection unit, that is: ； in represents the phase shift value corresponding to the maximum expected value, and n represents the The nth reflection unit of the smart reflection surface Indicates A possible phase shift, , represents the number of possible phase shifts per unit, represents the phase shift set, For one dimensional vector, whose components correspond to the The phase shift of a reflective unit of a smart reflective surface, Indicates all The measurement samples satisfy If there are multiple phase shift values ​​that maximize the conditional sample expectation, then any one is selected.

6. The positioning system based on dual intelligent reflective surfaces as claimed in claim 1, characterized in that: The locator determines the location of the unknown transmitter by: The locator determines the position of the unknown transmitter according to the dual intelligent reflector positioning algorithm; the dual intelligent reflector positioning algorithm specifically includes: Smart reflective surface has Reflection unit, A planar array of For along The number of reflection units in the axial direction, For along The number of reflection units in the axial direction, The reflection unit is in the On the smart reflective surface Row, No. The reflection unit of the column, is the direct channel from transmitter to receiver, For the The reflection channel introduced by the reflection unit, is the phase difference between the direct channel and the reflected channel. According to the properties of the line-of-sight channel, for the Two adjacent reflection units on the same row of a smart reflection surface as well as ,but: ； For Two adjacent reflective units on the same row of a smart reflective surface as well as ,but: ； in, is the wavelength of the carrier used to transmit the signal, is the distance between two adjacent reflection units, The transmitter arrives at The vertical angle of arrival of the first intelligent reflective surface, The vertical departure angle of the smart reflector from the receiver to the transmitter to the The horizontal arrival angle of the first smart reflector, The horizontal departure angle from the smart reflector to the receiver; Optimize the reflection unit of the smart reflective surface As a pair An optimal estimate based on random samples ,Right now , the locator will be based on as well as Let's first estimate and ,according to and The relationship between When there are reflection units, we get Independent estimates of: ,in , Express Independent estimates of Take the average of all independent estimates as the pair The final estimate of: ; For The number of independent estimates of Express The final estimate of Based on The final estimate of and The relationship between When the reflection unit Independent estimates of: , Express Independent estimates of Take the average of all independent estimates as the pair The final estimate of: ; For The number of independent estimates of Express The final estimate of Finally, based on the two known coordinates of the smart reflector and the estimated arrival angle from the transmitter to the smart reflector , draw two rays, and the coordinates of the intersection of the two rays are the final estimate of the unknown transmitter position.

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