An indoor positioning system and method based on a multi-waveguide multi-clamp antenna

Abstract

This invention relates to an indoor positioning system and method based on a multi-waveguide, multi-clamping antenna. The positioning system includes an access point, a central processor, three waveguides, several clamping antennas, and a transmitter. The access point is located in a corner of the room's ceiling and connected to the central processor. The three waveguides are connected to the access point and extend along the ceiling. x axis, y Axial and diagonal distribution, with [missing information] distributed on each waveguide. N The clamping antennas described herein have randomly distributed transmitters. The positioning method includes: first, simultaneously activating multiple clamping antennas on different waveguides; establishing a position estimation equation based on the received power closed-form expression and the actual received power at the access point; then, dividing the room into grid points and calculating the theoretical received power of all grid points; then, selecting the region with the smallest error to refine the grid and repeatedly evaluating the error function, gradually reducing the grid size to achieve the required positioning resolution; finally, selecting the grid point with the smallest error as the estimated user position. This invention enables accurate positioning in indoor scenarios.

Description

Technical Field

[0001] This invention relates to the field of wireless communication and positioning technology, specifically to an indoor positioning system and method based on a multi-waveguide multi-clamping antenna. Background Technology

[0002] In modern indoor environments, high-precision positioning technology has become one of the key supporting technologies for smart homes, industrial monitoring, emergency rescue, and other fields. With the continuous upgrading of the application requirements in indoor scenarios, higher demands are being placed on the positioning accuracy, signal stability, deployment flexibility, and cost control of positioning systems. Traditional indoor positioning technologies are gradually showing many limitations in practical applications, making it difficult to meet the precise positioning needs in complex indoor environments.

[0003] Most existing indoor positioning systems use distributed antennas to directly receive signals from target transmitters. This dispersed antenna layout necessitates a separate signal processing module for each antenna, increasing system hardware costs and deployment complexity. Furthermore, signal synchronization issues between antennas can negatively impact positioning accuracy. Simultaneously, signal transmission between existing antennas and signal access points often relies on wireless or wired channels, which are susceptible to attenuation and interference during transmission, further degrading the quality of the received signal and leading to significant errors in subsequent ranging and positioning calculations based on signal strength or propagation time. Therefore, there is an urgent need to improve existing indoor positioning systems and address their technical challenges, including insufficient positioning accuracy, poor signal stability, and high deployment costs. Summary of the Invention

[0004] To address the aforementioned problems in the prior art, this invention provides an indoor positioning system and method based on multi-waveguide multi-clamping antennas. This technical solution utilizes the high-coupling-efficiency dielectric particles and low-attenuation polytetrafluoroethylene dielectric waveguides of the clamping antenna system (PASS) to optimize the signal transmission path, improve antenna coupling efficiency and signal transmission stability, effectively shield electromagnetic interference and reduce multipath effects, significantly improving positioning accuracy and signal stability. It can meet the application requirements of modern indoor environments for high-precision, high-stability and low-cost positioning technology.

[0005] To achieve the above objectives, this invention proposes an indoor positioning system based on multi-waveguide multi-clamping antennas, comprising an access point, a central processor, three waveguides, several clamping antennas, and a transmitting source; the indoor positioning system is applied within a room, the room dimensions of which are: x ∈[0, D 1], y ∈[0, D 2], z ∈[0, hThe access point is located in a corner of the room's ceiling and connected to the central processor. The three waveguides are connected to the access point and run along the ceiling. x axis, y The three waveguides are distributed along the axis and diagonal, and their spans are defined as follows: W 1∈[(0, D 1), 0, h ], W 2∈[(0, D 2), 0, h ], W 3∈[(0, D 1),(0, D 2), h Each waveguide is distributed with N The clamping antennas are one in number, and the distance between two clamping antennas is... d ;No. i The center coordinates of the clamped antenna array on the waveguide are defined as follows: L i =[ x i , y i , h ],in, i =1,2,3, representing the distances along the ceiling, respectively. x axis, y The waveguides are distributed along the axis and diagonal; the emission sources are randomly distributed within the room, and the coordinates of the emission sources are defined as follows: U =[ x u , y u ,0]; The channel between the transmitter and the clamping antenna array is a free-space channel, and the channel between the clamping antenna array and the access point is a waveguide channel. The signal is emitted from the transmitter, passes through the free-space channel, and enters... N In the clamping antenna, the signal then propagates through the waveguide, and the signal on the same waveguide is superimposed at the access point.

[0006] The present invention can improve the array gain of downlink communication by using multiple clamping antennas arranged on each waveguide.

[0007] Furthermore, the indoor positioning system operates in a far-field scenario, and the free-space channel experiences large-scale fading. h ls ( d ui This is approximately the large-scale fading from the transmitter to the center of the clamping antenna array. The expression is: ; in: j It is an imaginary number. c Represents the speed of light. f c Indicates the carrier frequency. d ui Indicates the source of the emission and the first i The distance between the centers of the clamped antenna array on the root waveguide d ui The expression is: ; The small-scale fading h ss ( d in The expression for ) is: ; in: λ Indicates the signal wavelength. d in Indicates the source of the emission and the first i The first waveguide on the root waveguide n The distance between the clamping antennas, d in The expression is: ; in: Indicates the source of the emission and the first i The included angle between the centers of the clamping antenna array on the root waveguide; The expression for the waveguide channel gain is: ; in: ε r Represents the relative permittivity. This represents the tangent of the loss angle.

[0008] Furthermore, the clamping antenna is a dielectric particle, operates at a frequency of 2.4 GHz, and has a coupling efficiency of not less than 85%.

[0009] Furthermore, the waveguide is a strip-shaped dielectric waveguide made of polytetrafluoroethylene, and its operating frequency band matches that of the clamping antenna, with an attenuation coefficient not greater than 0.02dB / m.

[0010] To address the aforementioned problems in the prior art, the present invention also provides an indoor positioning method based on a multi-waveguide multi-clamping antenna. The method is implemented using any of the preferred embodiments of the above-described indoor positioning system based on a multi-waveguide multi-clamping antenna, and specifically includes the following steps: S110: Assuming the transmitter is a single antenna, and multiple clamping antennas on different waveguides are activated simultaneously, the actual power intensity of the received signal is measured, and a position estimation equation is established. This includes the following steps: Signals on the same waveguide are superimposed at the access point, and the signal received at the access point comes from the first waveguide. i Superposition of signals from root waveguides r i The expression is: ; in: s In order to transmit signals, P s For signal transmission power, η i It has a mean of 0 and a variance of Additive white Gaussian noise, The expression is: ; As can be seen from the superimposed signal expression, the position of the transmitting source is related to the received signal power. Therefore, the superimposed signal can be derived. r i Closed expression: To simplify the analysis, define ,get ,Right now d =1, therefore, the waveguide loss from each clamped antenna to the access point is approximately equal to the loss from the array center to the access point, the superimposed signal r i The expression is: ; right d in Performing a first-order Taylor expansion, the expression is: ; in: , ; Distance after first-order Taylor expansion d in Substitute the superimposed signal r i In the expression, the superimposed signal r i The expression is transformed into: ; definition The summation term in the superimposed signal expression is: ; Therefore, the first i Superposition of signals from root waveguidesr i The closed-form expression is: ; Based on the closed-form expression of the superimposed signal, the first... i Based on the received power of the root waveguide, establish the positioning equation: Received power P thi The expression is: ; in: r i and , η i and All are conjugate parameters; This represents the power of additive white Gaussian noise, where the punctuation mark "~" means "subject to". Assuming the actual received power is P ri The equation for the location is: ; S120: Using the grid search method, estimate the user's location: First, divide the room into several coarse grid points, and use the closed expression of the received power to calculate the theoretical received power of all grid points; S130: Define the error function as follows: ; Select the area with the smallest error for further subdivision, repeatedly evaluate the error function on the refined grid, and gradually reduce the grid size to achieve the required positioning resolution; S140: Select the grid point with the smallest error, which is the estimated user location.

[0011] The present invention provides a computer-readable storage medium including a stored computer program, which, when executed, implements the above-mentioned preferred indoor positioning method based on a multi-waveguide multi-clamping antenna.

[0012] The present invention provides a computer program product, including a computer program, which, when executed, implements the above-mentioned preferred indoor positioning method based on a multi-waveguide multi-clamping antenna.

[0013] Compared with the prior art, the advantages of this invention are: This invention applies the advantages of the PASS (Plagging Antenna System) in terms of strong positioning adaptability and stable channel transmission to indoor positioning technology solutions. By simultaneously activating multiple clamping antennas on different waveguides and using grid search to estimate the location of the transmitting source, it can ensure real-time positioning, improve the array gain of downlink communication, and cover the entire room with just three waveguides. It is particularly suitable for indoor scenarios, thus providing strong support for engineering implementation. Attached Figure Description

[0014] Figure 1 This is a flowchart illustrating a preferred embodiment of the indoor positioning method based on a multi-waveguide multi-clamping antenna of the present invention. Figure 2 This is a schematic diagram of a preferred embodiment of the indoor positioning system based on a multi-waveguide multi-clamping antenna of the present invention. Figure 3 This is a schematic diagram comparing the positioning error performance of a preferred embodiment of the indoor positioning system based on multi-waveguide multi-clamping antennas of the present invention under different waveguide distributions and different numbers of clamping antennas on each waveguide. Detailed Implementation

[0015] To make the objectives, advantages and features of the present invention more apparent, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0016] To address the aforementioned problems in the prior art, this invention provides an indoor positioning system based on a multi-waveguide, multi-clamping antenna, such as... Figure 2 As shown, it includes an access point, a central processor, three waveguides, several clamping antennas, and a transmitter; the indoor positioning system is applied inside a room, the room dimensions of which are: x ∈[0, D 1], y ∈[0, D 2], z ∈[0, h The access point is located in a corner of the room's ceiling and connected to the central processor. The three waveguides are connected to the access point and run along the ceiling. x axis, y The three waveguides are distributed along the axis and diagonal, and their spans are defined as follows: W 1∈[(0, D 1), 0, h ], W 2∈[(0, D 2), 0, h ], W 3∈[(0, D 1),(0, D 2), h Each waveguide is distributed withN The clamping antennas are one in number, and the distance between two clamping antennas is... d ;No. i The center coordinates of the clamped antenna array on the waveguide are defined as follows: L i =[ x i , y i , h ],in, i =1,2,3, representing the distances along the ceiling, respectively. x axis, y The waveguides are distributed along the axis and diagonal; the emission sources are randomly distributed within the room, and the coordinates of the emission sources are defined as follows: U =[ x u , y u ,0]; The channel between the transmitter and the clamping antenna array is a free-space channel, and the channel between the clamping antenna array and the access point is a waveguide channel. The signal is emitted from the transmitter, passes through the free-space channel, and enters... N In the clamping antenna, the signal then propagates through the waveguide, and the signal on the same waveguide is superimposed at the access point.

[0017] This embodiment can improve the array gain of downlink communication by setting multiple clamping antennas on each waveguide.

[0018] Optionally, the indoor positioning system is used in a far-field scenario, where the free-space channel experiences large-scale fading. h ls ( d ui This is approximately the large-scale fading from the transmitter to the center of the clamping antenna array. h ls ( d ui The expression is: ; in: j It is an imaginary number. c Represents the speed of light. f c Indicates the carrier frequency. d ui Indicates the source of the emission and the first i The distance between the centers of the clamped antenna array on the root waveguide d ui The expression is: ; The small-scale fading h ss ( d in The expression for ) is: ; in: λ Indicates the signal wavelength. d in Indicates the source of the emission and the first i The first waveguide on the root waveguide n The distance between the clamping antennas, d in The expression is: ; in: Indicates the source of the emission and the first i The included angle between the centers of the clamping antenna array on the root waveguide; The expression for the waveguide channel gain is: ; in: ε r Represents the relative permittivity. This represents the tangent of the loss angle.

[0019] Optionally, the clamping antenna is a dielectric particle, operates at a frequency of 2.4 GHz, and has a coupling efficiency of not less than 85%.

[0020] Optionally, the waveguide is a strip-shaped dielectric waveguide made of polytetrafluoroethylene, with an operating frequency band matching the clamping antenna and an attenuation coefficient not greater than 0.02dB / m.

[0021] To address the aforementioned problems in the prior art, the present invention also provides an indoor positioning method based on a multi-waveguide multi-clamping antenna. The method is implemented using any of the preferred embodiments of the above-described indoor positioning system based on a multi-waveguide multi-clamping antenna, and specifically includes the following steps: S110: Assuming the transmitter is a single antenna, and multiple clamping antennas on different waveguides are activated simultaneously, the actual power intensity of the received signal is measured, and a position estimation equation is established. This includes the following steps: Signals on the same waveguide are superimposed at the access point, and the signal received at the access point comes from the first waveguide. Superposition of signals from root waveguides r i The expression is: ; in: s In order to transmit signals, P s For signal transmission power, ηi It has a mean of 0 and a variance of Additive white Gaussian noise, The expression is: ; As can be seen from the superimposed signal expression, the position of the transmitting source is related to the received signal power. Therefore, the superimposed signal can be derived. r i Closed expression: To simplify the analysis, define ,get ,Right now d =1, therefore, the waveguide loss from each clamped antenna to the access point is approximately equal to the loss from the array center to the access point, the superimposed signal r i The expression is: ; right d in Performing a first-order Taylor expansion, the expression is: ; in: , ; Distance after first-order Taylor expansion d in Substitute the superimposed signal r i In the expression, the superimposed signal r i The expression is transformed into: ; definition The summation term in the superimposed signal expression is: ; Therefore, the first i Superposition of signals from root waveguides r i The closed-form expression is: ; Based on the closed-form expression of the superimposed signal, the first... i Based on the received power of the root waveguide, establish the positioning equation: Received power P thi The expression is: ; in: r i and , ηi and All are conjugate parameters; This represents the power of additive white Gaussian noise, where the punctuation mark "~" means "subject to". Assuming the actual received power is The equation for the location is: ; S120: Using the grid search method, estimate the user's location: First, divide the room into several coarse grid points, and use the closed expression of the received power to calculate the theoretical received power of all grid points; S130: Define the error function as follows: ; Select the area with the smallest error for further subdivision, repeatedly evaluate the error function on the refined grid, and gradually reduce the grid size to achieve the required positioning resolution; S140: Select the grid point with the smallest error, which is the estimated user location.

[0022] The present invention provides a computer-readable storage medium including a stored computer program, which, when executed, implements the above-mentioned preferred indoor positioning method based on a multi-waveguide multi-clamping antenna.

[0023] The present invention provides a computer program product, including a computer program, which, when executed, implements the above-mentioned preferred indoor positioning method based on a multi-waveguide multi-clamping antenna.

[0024] Compared with the prior art, the advantages of this invention are: This invention applies the advantages of the PASS (Plagging Antenna System) in terms of strong positioning adaptability and stable channel transmission to indoor positioning technology solutions. By simultaneously activating multiple clamping antennas on different waveguides and using grid search to estimate the location of the transmitting source, it can ensure real-time positioning, improve the array gain of downlink communication, and cover the entire room with just three waveguides. It is particularly suitable for indoor scenarios, thus providing strong support for engineering implementation.

[0025] The following is in conjunction with the appendix Figure 1-3 The simulation parameters in Table 1 are used to provide a detailed description of the indoor positioning system and method based on multi-waveguide multi-clamping antenna of the present invention, clarifying the complete positioning process of system deployment, signal transmission, ranging and positioning and performance verification.

[0026] Table 1: <![CDATA[Axis scale of the x room D 1]]> 6m <![CDATA[Axis scale of the y room D 2]]> 10m Room axial dimensions 3m carrier frequency 2.4GHz Relative permittivity <![CDATA[ ε r =2.08]]> Loss tangent tan=0.0004 Transmitter power 0.1W This embodiment uses a typical indoor scene as the application object, and sets the three-dimensional dimensions of the room as follows: x 6m shaft y10m shaft z A 3m axis is used to fix the access point in a corner of the room's ceiling and connect it to the central processor. A strip-shaped dielectric waveguide adapted to the 2.4GHz carrier frequency is selected and connected to the access point along the ceiling. x axis, y The waveguides are laid out along the axis and diagonally, with the waveguide span adapted to the length of the ceiling edge; the distribution position on each waveguide is adjustable. N One clamping antenna, the distance between two of the clamping antennas is d ;No. i The center coordinates of the clamped antenna array on the waveguide are defined as follows: L i =[ x i , y i , h ],in, i =1,2,3, representing the distances along the ceiling, respectively. x axis, y The waveguides are distributed along the axis and diagonal; the emission sources are randomly distributed within the room, and the coordinates of the emission sources are defined as follows: U =[ x u , y u ,0].

[0027] In operation, this indoor positioning system based on a multi-waveguide, multi-clamping antenna emits a signal with a transmission power of 0.1W. The signal is first transmitted to the clamping antenna via a free-space channel. During this process, the free-space channel experiences both large-scale and small-scale fading. This requires consideration of the speed of light, the wavelength corresponding to the carrier frequency, and the relationship between the transmitter and the clamping antenna. i The actual distance between the clamping antennas (calculated using the distance formula between two points) is used to calculate the signal attenuation through the corresponding fading expression. The signal then enters the clamping antenna and is transmitted to the access point via the waveguide channel. The waveguide channel gain is calculated based on the set relative permittivity and loss tangent (see Table 1) using the waveguide channel gain expression to ensure low-loss signal transmission within the waveguide and reduce the impact of external electromagnetic interference on signal quality.

[0028] The positioning process of this indoor positioning method based on multi-waveguide multi-clamp antenna is performed according to the following steps: First, antenna activation and signal reception are performed: multiple clamping antennas on each waveguide are activated simultaneously to ensure real-time positioning; the access point receives signals from each waveguide, records the effective signal components other than additive white Gaussian noise in the closed-form expression of the signal, and, combined with a transmission power of 0.1W, obtains preliminary basic signal information; Secondly, establish the location estimation equation: measure the actual received power at the access point, and establish the location estimation equation based on the relationship between the received power and the square of the signal amplitude; Next, grid search estimation: Divide the room into several grid points, and use the closed-form expression of the received power to calculate the theoretical received power of all grid points; Subsequently, the region with the smallest error is selected for further subdivision. The error function is repeatedly evaluated on the refined grid, and the grid size is gradually reduced to achieve the required positioning resolution. Finally, the grid point with the smallest error is selected as the estimated user location.

[0029] To verify system performance, this embodiment tests the global positioning error under different noise intensities by adjusting the waveguide distribution and the number of clamping antennas. The following section combines... Figure 3 This simulation example describes the performance comparison of positioning error under different waveguide distributions and different numbers of antennas clamped on each waveguide. Figure 3 As shown, the positioning performance of the non-parallel waveguide distribution is superior to that of the parallel distribution across the entire noise range, and the performance gap widens further at higher noise power. This indicates that the non-parallel waveguide distribution can improve positioning accuracy and robustness. The slope of the parallel waveguide distribution is steeper than that of the non-parallel distribution, indicating that the parallel distribution is more sensitive to noise, while the non-parallel distribution exhibits more stable performance in high-noise regions. Furthermore, as the number of antennas held in the array increases, the average positioning error increases, and the lower limit of positioning performance decreases.

[0030] The above embodiments have provided a detailed description of the technical solution of the present invention. Obviously, the present invention is not limited to the described embodiments. Based on the embodiments of the present invention, those skilled in the art can make various modifications, but any modifications that are equivalent to or similar to the present invention fall within the scope of protection of the present invention.

Claims

1. An indoor positioning system based on a multi-waveguide multi-clamping antenna, characterized in that, The system includes an access point, a central processor, three waveguides, several clamping antennas, and a transmitter; the indoor positioning system is used inside a room, the room dimensions of which are: x ∈[0, D 1], y ∈[0, D 2], z ∈[0, h The access point is located in a corner of the room's ceiling and connected to the central processor. The three waveguides are connected to the access point and run along the ceiling. axis, The three waveguides are distributed along the axis and diagonal, and their spans are defined as follows: W 1∈[(0, D 1), 0, h ], W 2∈[(0, D 2), 0, h ], W 3∈[(0, D 1),(0, D 2), h Each waveguide is distributed with N The clamping antennas are one in number, and the distance between two clamping antennas is... d ;No. i The center coordinates of the clamped antenna array on the waveguide are defined as follows: L i =[ x i , y i , h ],in, i =1,2,3, representing the distances along the ceiling, respectively. x axis, y The waveguides are distributed along the axis and diagonal; the emission sources are randomly distributed within the room, and the coordinates of the emission sources are defined as follows: U =[ x u , y u ,0]; The channel between the transmitter and the clamping antenna array is a free-space channel, and the channel between the clamping antenna array and the access point is a waveguide channel. The signal is emitted from the transmitter, passes through the free-space channel, and enters... N In the clamping antenna, the signal then propagates through the waveguide, and the signal on the same waveguide is superimposed at the access point.

2. The indoor positioning system based on a multi-waveguide multi-clamping antenna as described in claim 1, characterized in that, The indoor positioning system operates in a far-field scenario, and the free-space channel experiences large-scale fading. h ls ( d ui This is approximately the large-scale fading from the transmitter to the center of the clamping antenna array. h ls ( d ui The expression is: ； in: j It is an imaginary number. c Represents the speed of light. f c Indicates the carrier frequency. d ui Indicates the source of the emission and the first i The distance between the centers of the clamped antenna array on the root waveguide d ui The expression is: ； The small-scale fading h ss ( d in The expression for ) is: ； in: λ Indicates the signal wavelength. d in Indicates the source of the emission and the first i The first waveguide on the root waveguide n The distance between the clamping antennas, d in The expression is: ； in: Indicates the source of the emission and the first i The included angle between the centers of the clamping antenna array on the root waveguide; The expression for the waveguide channel gain is: ； in: ε r Represents the relative permittivity. This represents the tangent of the loss angle.

3. The indoor positioning system based on a multi-waveguide multi-clamping antenna as described in claim 1, characterized in that, The clamping antenna is a dielectric particle, operates at a frequency of 2.4 GHz, and has a coupling efficiency of not less than 85%.

4. The indoor positioning system based on a multi-waveguide multi-clamping antenna as described in claim 1, characterized in that, The waveguide is a strip-shaped dielectric waveguide made of polytetrafluoroethylene, and its operating frequency band matches that of the clamping antenna, with an attenuation coefficient of no more than 0.02dB / m.

5. An indoor positioning method based on a multi-waveguide multi-clamping antenna, characterized in that, The method is implemented using the indoor positioning system based on a multi-waveguide multi-clamping antenna as described in any one of claims 1-4, and specifically includes the following steps: S110: Assuming the transmitter is a single antenna, and multiple clamping antennas on different waveguides are activated simultaneously, the actual power intensity of the received signal is measured, and a position estimation equation is established. This includes the following steps: Signals on the same waveguide are superimposed at the access point, and the signal received at the access point comes from the first waveguide. i Superposition of signals from root waveguides The expression is: ； in: s In order to transmit signals, P s For signal transmission power, η i It has a mean of 0 and a variance of Additive white Gaussian noise, The expression is: ； As can be seen from the superimposed signal expression, the position of the transmitting source is related to the received signal power. Therefore, the superimposed signal can be derived. Closed expression: To simplify the analysis, define ,get ,Right now d =1, therefore, the waveguide loss from each clamped antenna to the access point is approximately equal to the loss from the array center to the access point, the superimposed signal r i The expression is: ； right d in Performing a first-order Taylor expansion, the expression is: ； in: , ; Distance after first-order Taylor expansion d in Substitute the superimposed signal r i In the expression, the superimposed signal r i The expression is transformed into: ； definition The summation term in the superimposed signal expression is: ； Therefore, the first i Superposition of signals from root waveguides r i The closed-form expression is: ； Based on the closed-form expression of the superimposed signal, the first... i Based on the received power of the root waveguide, establish the positioning equation: Received power P thi The expression is: ； in: r i and , η i and All are conjugate parameters; This represents the power of additive white Gaussian noise; Assuming the actual received power is P ri The equation for the location is: ； S120: Using the grid search method, estimate the user's location: First, divide the room into several coarse grid points, and use the closed expression of the received power to calculate the theoretical received power of all grid points; S130: Define the error function as follows: ； Select the region with the smallest error function for further subdivision, repeatedly evaluate the error function on the refined grid, and gradually reduce the grid size to achieve the required positioning resolution; S140: Select the grid point with the smallest error function, which is the estimated user location.

6. A computer-readable storage medium, characterized in that, It includes a stored computer program, which, when executed, implements the indoor positioning method based on a multi-waveguide multi-clamping antenna as described in claim 5.

7. A computer program product, characterized in that, The system includes a computer program that, when executed, implements the indoor positioning method based on a multi-waveguide multi-clamping antenna as described in claim 5.

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