Method and system for calibrating process of positioning device

Abstract

The invention relates to a method for calibrating a positioning system. The method comprises the following steps: transmitting a calibration signal from a calibration device located at a first known position; receiving, by the calibration device, a reflection of the calibration signal from a positioning element located at a second known position, where the reflection carries identification information of the positioning element; analyzing a characteristic of the reflection using the first known position and the second known position to determine a reflection characteristic of the positioning element; calibration information including reflection characteristics of the positioning element is stored for use in the process of positioning the user equipment.

Description

Technical Field

[0001] This application relates to the field of device positioning, and particularly to a method and system for calibrating a device for positioning using reflected electromagnetic signals. Background Art

[0002] There are various techniques for identifying the location of a mobile device of an end user or a user equipment (UE), which may include a mobile phone, a laptop computer, a tablet computer, or other devices connected to a mobile telecommunications system.

[0003] Specifically, positioning methods based on timing, angle, and carrier phase have been applied to Wi-Fi, 4G, 5G, and global network satellite systems (GNSS). These methods may include transmitting signals from a base station or other server-side devices to the UE, and then performing subsequent processing to infer the location of the UE relative to the transmitting device from these signals.

[0004] In some processes, powerless or low-power tags have been used to provide positioning signals. For example, radio frequency identification (RFID) tags may be used. Such tags may be ambient power (AMP) tags, i.e., tags that do not have an external power source but obtain energy from the surrounding environment (e.g., through solar energy). A particular advantage of such tags is that they can be flexibly deployed without power limitations, thus facilitating the provision of positioning services in areas where other signal types may perform poorly. For example, GNSS-based positioning may encounter difficulties inside buildings, and it may always be impossible to obtain sufficient cellular signals to accurately locate the UE.

[0005] Therefore, the flexibility of AMP tags can bring significant advantages, but the requirement to minimize power usage poses challenges to traditional positioning techniques. Specifically, AMP tags may not be able to transmit broadband positioning reference signals (PRS). Therefore, positioning methods based on timing (e.g., Observed Time Difference Of Arrival (OTDOA)) may not achieve satisfactory positioning accuracy.

[0006] For the same reason, angle-based positioning is also not applicable because AMP tags can neither accurately measure the angle of incoming signals nor transmit / reflex equivalent direction signals to the UE.

[0007] It has been proposed to use carrier-phase-based AMP tag positioning. Advantageously, this technology does not require a wide bandwidth to achieve theoretically high positioning accuracy. However, accurately inferring distance from the measured phase remains challenging.

[0008] There is still a need to improve the ability to implement positioning or location technologies so that low-power or zero-power tags (such as AMP tags) can be utilized, thereby enhancing the ability to take advantage of the flexible deployment of such tags while maintaining accuracy and reliability. SUMMARY OF THE INVENTION

[0009] Embodiments of the present application provide a method and system for positioning a mobile device (such as a UE) to overcome problems associated with traditional methods and devices.

[0010] According to one aspect, a method for calibrating a positioning system is provided. The method includes: sending a calibration signal from a calibration device located at a first known position. Then, the calibration device receives a reflection of the calibration signal from a positioning element located at a second known position, and the reflection carries identification information of the positioning element. Using the first known position and the second known position, analyze the characteristics of the reflection to determine the reflection characteristics of the positioning element. Store calibration information including the reflection characteristics of the positioning element for use in the process of positioning a user equipment.

[0011] According to a second aspect, a method for positioning a user equipment is provided. The method includes sending a positioning signal from the user equipment to a plurality of positioning elements, each positioning element having a known position. Then, at the user equipment, receive a reflection of the positioning signal from the positioning element. Each reflection of the positioning signal carries identification information of the positioning element that reflected the positioning signal. Based on the characteristics of the received reflections from the positioning elements and the calibration information obtained by the method of the first aspect, calculate the distance between the user equipment and the positioning elements. Identify the position of the user equipment based on the calculated distances and the known positions.

[0012] According to a third aspect, a calibration system is provided, which includes a calibration device located at a first known position, a positioning element located at a second position, and a server. Send a positioning signal from the calibration device to the positioning element. Then, the calibration device receives a reflection of the calibration signal from the positioning element, and the reflection carries identification information of the positioning element. Then, the calibration device or the server can analyze the characteristics of the reflection using the first known position and the second known position to determine the reflection characteristics of the positioning element. Then, store calibration information including the reflection characteristics of the positioning element in the server for use in the process of positioning a user equipment.

[0013] These and other aspects of the present application will become more apparent from the following description and the appended claims with reference to the accompanying drawings, all of which form a part of this specification, where the same reference numerals denote corresponding parts in each figure. It should be clearly understood, however, that the drawings are for illustrative and descriptive purposes only and are not intended to limit the scope of protection. Description of the Drawings

[0014] Embodiments will now be described in conjunction with the accompanying drawings, where:

[0015] Figure 1 A calibration system for obtaining calibration information used in the process of acquiring a positioning device is shown;

[0016] Figure 2 An embodiment in which the calibration device is implemented as a fixed signal generator is shown;

[0017] Figure 3 An embodiment in which the calibration device is implemented as a mobile signal generator is shown;

[0018] Figure 4 An embodiment in which the calibration device is implemented as a user equipment is shown;

[0019] Figure 5 A process for obtaining calibration information according to an embodiment is shown;

[0020] Figure 6 Devices that can be used in the process of a positioning device are shown;

[0021] Figures 7(a) and 7(b) show the process of positioning a device using calibration information. Detailed Description of the Embodiments

[0022] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings.

[0023] Figure 1 A calibration system for obtaining calibration information that can be used to calibrate the operation of a positioning system is shown. The calibration system includes a calibration device 110, a plurality of positioning elements 120, and a server 130.

[0024] The calibration device 110 can be coupled to the server 130 via the network 140. For example, a network link can provide data communication between the calibration device 110 and the server 130 through one or more networks. For example, the network link can be connected to a host computer through a local network or to a data device operated by an Internet Service Provider (ISP). The ISP in turn provides data communication services through the global packet data communication network now commonly referred to as the "Internet". Both the local network and the Internet can use electrical signals, electromagnetic signals, or optical signals carrying digital data streams.

[0025] The calibration device 110 is configured to generate a calibration signal. The calibration signal can be a wireless signal, such as a Bluetooth signal. The calibration signal can be an electromagnetic signal. The calibration device 110 is capable of receiving such signals and identifying data therefrom as well as identifying characteristics such as the phase and time of the signal.

[0026] The positioning element 120 can be an ambient power (AMP) tag (such as an RFID tag), which is configured to reflect an incoming signal carrying identification information identifying each element. Thus, when the calibration signal from the calibration device 110 impinges on the positioning element 120, the signal may be reflected, and the reflection can be received by the calibration device 110. Since the reflection from the positioning element 120 includes the identification information of the positioning element 120, the calibration device 110 can identify the source of the reflection.

[0027] Each positioning element 120 has a known location, which can be stored at the server 130 and / or elsewhere, such as by the calibration device 110. In addition, the location of the calibration device 110 is known. Thus, when a reflection from the positioning element 120 is received at the calibration device 110, one or more reflection characteristics of the positioning element 120 can be inferred, which will be discussed in further detail below.

[0028] The calibration device 110 can be implemented in any suitable technological form. The calibration device can be a fixed device or a mobile device. The calibration device can be a general computing device having one or more other functions besides the calibration process, such as a desktop computer, a laptop computer, a tablet computer, or any other device. The calibration device can be a terminal device, such as a user equipment (UE), an access terminal, a user unit, a user station, a mobile station, a remote station, a remote terminal, a mobile device, a user terminal, a terminal, a wireless communication device, a user agent, or a user device. However, the embodiments of the present application are not limited thereto.

[0029] Figures 2 to 4 A specific embodiment of the calibration system 100 is shown, where the calibration device 110 takes certain forms.

[0030] In Figure 2 's embodiment, the calibration device 110 is implemented as a fixed signal generator (FSG). The fixed mobile signal generator can generate the same signals as the terminal devices or UEs in the network (i.e., the same waveforms, signal structures, carrier frequencies, etc.), and can be deployed throughout the area where the positioning service is provided. These signal generators 110 can also have a phase measurement function and are connected to the server 130, where all the positioning element 120 (AMP tag related) information is stored as shown in Figure 2 . Figure 2 The data structure 200 recorded on the server is also schematically shown, where each row {para 1 = ID of AMP Tag i, para 2 = θps,i, para 3,...} represents the AMP tag information vector and contains the parameters to be used in the positioning as described below.

[0031] Using the FSG 110 as the calibration device has many advantages. For example, due to its permanent presence, this can allow timely measurement of reflection characteristics such as phase shift. By deploying the FSG with high density, improved accuracy can be achieved, and the reflection characteristics can be measured at any time when needed, etc. However, deploying the FSG incurs additional deployment costs and operating costs.

[0032] In Figure 3 's alternative embodiment, a mobile signal generator (MSG) is used as the calibration device 110. Similar to the FSG, the MSG can also generate the same signals as the UEs. However, the MSG can traverse the service area at a known position at any given time. For example, the MSG can move throughout the positioning service area along a predetermined trajectory, as shown in Figure 3 .

[0033] The phase measurement and reporting process of the MSG is similar to that of the FSG, but the position of the MSG during measurement should also be reported to the server 130. The position of the MSG can be obtained based on the starting time, the moving speed of the MSG, the predetermined trajectory information, etc.

[0034] Compared with FSG, MSG may require lower deployment costs because a single device can cover a wider area. For example, in extreme cases, only one MSG is needed to traverse the entire service area to measure all AMP tags, although in other methods, multiple MSGs can be provided for a given area. However, as mentioned above, MSG must report additional information during operation, such as the location of the MSG. If the location of the MSG cannot be accurately estimated when measuring the reflected characteristics, it may affect the calibration accuracy performance. Similarly, the flexibility to measure the reflections from a given positioning element 120 will also be reduced. In some cases, MSG may be impractical. For example, the MSG may not easily traverse the area, or the presence of the MSG may interfere with other users of the environment, such as people and vehicles. This may be particularly problematic during the day.

[0035] In Figure 4 the example shown, the calibration device 110 is implemented as a UE. Similar to Figure 3 the embodiment of, the UE is mobile, and for the same reason, it is necessary to report its location to the server during the classification process. This can be achieved in various ways, which may include using the positioning element 120 itself to locate the UE.

[0036] For example, since the cost of AMP tags is low, it may be feasible to deploy such tags at high density as the positioning element 120. In this case, multiple AMP tags can surround a UE. The AMP tags that the UE can use to measure the reflected characteristics can be represented as a set χ = {τ1, τ2, …, τN}, where N is the total number of surrounding AMP tags.

[0037] Given that the number of AMP tags in this example is quite large, the UE may not need to use all AMP tags for positioning. For example, only a subset of χ can be used to identify the location of the UE, and this subset can be represented as χ1. The remaining unused AMP tags can be represented as another subset χ2, where χ = {χ1, χ2}.

[0038] In one method, once the location of the target UE is obtained using the tags in subset χ1, it can be used to improve the understanding of the reflected characteristics of the AMP tags in subset χ2. To be able to perform this operation with a high degree of confidence, it is best to implement this process only when there is a high level of confidence in the positioning accuracy of the target UE. For example, the signal strength from the tags χ1 is high enough, such as above a predetermined threshold.

[0039] In another method, once the location of the target UE is obtained, it can be used to measure the reflected characteristics of newly deployed or repositioned AMP tags. Alternatively, the server 130 can provide instructions to the located UE to update the calibration of certain AMP tags.

[0040] Generally, in Figures 2 to 4 the embodiments of Figures 2 to 4 and other implementation schemes, multiple measurements can be performed on a positioning element 120 (AMP tag). This can be done by multiple calibration devices 110 (e.g., multiple FSG / MSG) and / or by the same calibration device at different times. When multiple measurements are used, the measured characteristics of the positioning element can be further processed, such as taking an average value or selecting a value with a higher confidence level. Then, the processed characteristics can be used to update the table in the server 130. The methods shown in

[0041] Figure 5 can be combined as appropriate Figures 1 to 4 to optimize efficiency.

[0042] In step 501, the calibration device 110 (e.g., FSG, MSG or UE) sends a calibration signal to an adjacent positioning element 110 (e.g., AMP tag). These signals may have the same form as the signals that the UE (which may or may not be the calibration device 110) will use for positioning later. For example, the calibration signal and the subsequent positioning signal may have the same waveform, signal structure, carrier frequency, etc.

[0043] In step 502, the calibration signal is reflected / scattered back by the positioning element 120 to generate a reflected signal. This reflected signal carries identification information that allows the positioning element 110 that reflected them to be identified. For example, in some embodiments, the positioning element 120 (AMP tag) sends its ID to the calibration device by backscattering a signal, and the same part of this signal is also used to measure the characteristics of the signal used in the calibration process (e.g., phase measurement).

[0044] However, in some cases, it is better to apply a technique to divide the reflected signal into a part that carries the ID of the positioning element 110 and a part that is used to measure the characteristics of the signal used during calibration. That is, the backscattered signal carrying the AMP tag ID may not be suitable for phase measurement. For example, it may be a discontinuous signal with on-off keying (OOK) modulation. In this case, time division can be adopted, i.e., one time slot is used for the backscattered signal carrying the AMP tag ID, and another time slot is used for backscattered signal phase measurement. Other modulation methods, such as frequency shift keying (FSK), can also be used, and in this case the same time division can be applied. Generally, it may be necessary to separate the time for ID transmission from the time for measuring the phase or any other characteristics of the reflected signal used for calibration.

[0045] In step 503, the calibration device 110 detects the AMP tag ID in the backscattered / reflected signal and measures the characteristics (e.g., phase) of the backscattered / reflected signal. In the case where multiple reflected signals are received simultaneously with temporal overlap, the calibration device may be able to distinguish signals from multiple AMP tags. For example, a time-division multiplexing solution can be adopted, where signals are multiplexed in the time domain, or frequency-division multiplexing can be used, where each AMP tag backscatters / reflects the incident signal with a different frequency shift. Generally speaking, for the purpose of distinguishing reflected / backscattered signals, those skilled in the art can adopt any suitable technique.

[0046] In step 504, the calibration device 110 sends, via a wired / wireless link, the ID received from the positioning element 120 in the backscattered signal and the signal characteristics (e.g., phase) information to the server 130. The calibration device can also transmit information related to the calibration signal (e.g., in the case where the signal characteristics for calibration are related to phase, information related to the phase of the transmitted signal can also be provided). When necessary, the calibration device 110 can also report its current position to the server 130.

[0047] In step 505, using the information received from the calibration device 110 and the position of the calibration device 110 (whether reported in step 504 or known to the server 130, such as in the example of using the FSG as the calibration device 110), the server is able to calculate information related to the reflection characteristics of the positioning element 120. For example, the server 130 can calculate the phase shift θps,i caused by the backscattering / reflection of the calibration signal by the AMP tag and update the relevant AMP tag information vector {para 1 = ID of AMP Tag i, para 2 = θps,i, para 3, …} accordingly.

[0048] As described above, the calibration device 504 reports information about the reflected signal, and the server 130 then obtains the reflection characteristics of the positioning element 120 itself from this information. However, it should be noted that if the calibration device 110 itself stores the relevant information, it can infer the reflection characteristics from the received signal by itself. For example, if the calibration device 110 is able to calculate the phase shift value, it can directly report the phase shift instead of reporting the measured phase in step 504.

[0049] The server 130 acts as a central node and maintains a table containing all AMP tag information vectors, which includes the reflection characteristics (phase shift) measured in this way. As described below, this can be used in the future process of positioning the UE or other devices.

[0050] As described above, it may be necessary to repeat at different time points Figure 5The process is to maintain the best record of the reflection characteristics of the available positioning elements. In a preferred embodiment, this may involve updating the AMP tag information vector table in a periodic or on-demand manner.

[0051] For example, in one method, the information stored on the server (e.g., the AMP tag information vector table) can be updated periodically by running the above process from time to time (e.g., according to a predetermined schedule). Thus, when new AMP tags are deployed, existing AMP tags are repositioned, or phase shifts change due to changes in the environment or the behavior of individual tags (e.g., circuit attenuation), the AMP tag information vector table can be updated. However, performing this process at a high frequency may significantly increase the energy consumption of the AMP tags because the incident signal needs to be backscattered periodically through modulation, which may pose a practical limitation to the effectiveness of such periodic updates.

[0052] Alternatively, the process can be performed in an on-demand manner. For example, it may be triggered by events such as the deployment of new AMP tags, the repositioning of existing AMP tags, a positioning error exceeding a specific threshold, etc. Thus, the calibration system 110 (and the positioning element 120) can generally remain dormant unless the server sends a trigger signal to the calibration device 110 to perform the process. Once the calibration device 110 receives such a signal, the pre-measurement / calibration program is initiated, and the AMP tag information vector table can be updated. The energy consumption in the on-demand mode can be significantly lower than that in the high-frequency periodic mode. In some examples, a hybrid approach can be adopted, i.e., performing on-demand calibration for specific identification events while performing relatively low-frequency periodic calibration.

[0053] According to the capabilities of the calibration device 110, a table of all adjacent AMP tags that require pre-measurement / calibration can also be maintained. This may be particularly suitable when the calibration device is an FSG. Through this table, the calibration device can compare the received ID with the local table and only send the ID and phase information of newly deployed or repositioned AMP tags.

[0054] In step 504, the calibration device 110 can also send a timestamp indicating the time when the reflected signal was observed, together with the ID and information related to the signal (e.g., phase information). This timestamp can be used to evaluate whether the current information about the signal is outdated and whether new measurements need to be performed.

[0055] Another optional parameter reported by the FSG is the confidence level of the measurement value, which can be a continuous value or a discrete value within a certain range, indicating the reliability of the phase measurement. The calibration information of a specific positioning element may only be updated when the threshold of this confidence level is met. This confidence level is associated with each measurement value or each AMP tag and can be determined based on one or more of the following criteria:

[0056] 1) The backscattered signal strength, where the higher the strength, the higher the confidence level;

[0057] 2) In a multipath scenario, the signal strength difference between the strongest path and the average strength of all detected paths. The greater the difference, the more likely the strongest path is a line-of-sight (LOS) link, and thus the higher the confidence level;

[0058] 3) The measurement time. It can be inferred that the environmental conditions at different times of the day are more suitable for confidence level measurement. For example, in public places, the confidence level at night is higher than that during the day because the LOS link is more likely to be achieved at night without crowds obstructing the LOS link.

[0059] When the server 130 has calibration information related to the reflection characteristics of the positioning element, this information can be used in the process of positioning the user equipment. For example, consider Figure 6 the scenario where the user equipment 610 is located near multiple positioning elements 120. Figure 6 The positioning element 120 is the same as the above-mentioned positioning element, while the user equipment 610 can be a different device, or can be, for example, Figure 4 the UE 110 described in the context of

[0060] Generally, the user equipment 610 can be a terminal device, such as a user equipment (UE), access terminal, user unit, user station, mobile station, remote station, remote terminal, mobile device, user terminal, terminal, wireless communication device, user agent, or user device. However, the embodiments of the present application are not limited thereto. The user equipment 610 can be coupled to a cellular network through which it can communicate with the server 140.

[0061] Figures 7(a) and 7(b) illustrate an example process of positioning the user equipment 610 using calibration information obtained by Figure 5 the method.

[0062] Figure 7(a) shows the positioning based on the user equipment 610. In this case, the user equipment (e.g., UE) emits a positioning signal at step 701, which is backscattered / reflected by the positioning element 120 near it and received at step 702. As described above, during the backscattering process, the identification information of each positioning element is transmitted into the signal.

[0063] In step 703, the user equipment 610 reports the observed identification information and requests calibration information related to this ID (e.g., in the form of a relevant AMP tag information vector) from the server 130. In step 704, the server 130 sends this information together with the known positions of the relevant positioning elements to the user equipment 610.

[0064] Then, the user equipment 610 can calculate its position based on the known positions of the positioning elements (from which reflected signals have been received) and one or more measured characteristics of these signals (e.g., phase). Additionally, by understanding the impact of the reflection process on the measured characteristics obtained from the calibration information, the accuracy of the calculated position can be improved.

[0065] The method in Fig. 7(b) differs from the method in Fig. 7(a) in that the calculation of the UE position is performed at the server 130. The initial part of this process is similar to that in Fig. 7(a), where steps 706 and 707 correspond to steps 701 and 702. That is, the user equipment (e.g., UE) emits a positioning signal in step 706, which is backscattered / reflected by the positioning elements 120 in its vicinity and received in step 707. As described above, during backscattering, the identification information of each positioning element is passed into this signal.

[0066] Then, the user equipment 610 can calculate the characteristics of the received reflected signal (e.g., the measured phase) and report it to the server 130 together with the identification information in step 708 at step 110.

[0067] Then, in step 709, the position of the user equipment 610 is calculated at the server based on the calibration information stored in the server (e.g., based on an AMP tag information vector table) and reported to the user equipment 610 in step 710. The user equipment 610 may encounter newly deployed or relocated AMP tags / other positioning elements 120 for which pre-measurement / calibration has not been performed, and thus the server 130 does not store their relevant calibration information. In this case, these positioning elements 120 should be excluded when calculating the position of the UE.

[0068] Although the above disclosure focuses on carrier-phase-based positioning, the same process can also be applied to other positioning methods to eliminate the ambiguity in the initial state. For example, for signal-strength-based positioning, the reflection loss can be used instead of the phase shift θps,i, and the same process can be adopted. Additionally, combinations of reflection characteristics can be calibrated simultaneously or sequentially and used when positioning the user equipment.

[0069] Each of the processes, methods, and algorithms described in the foregoing may be implemented by code modules executed by one or more computer systems or computer processors, including computer hardware, and may be fully or partially automated. These processes and algorithms may be implemented in whole or in part in dedicated circuitry.

[0070] The various features and processes described above may be used independently of one another or may be combined in various ways. All possible combinations and sub-combinations are intended to fall within the scope of the present disclosure. Additionally, in some embodiments, certain method or process blocks may be omitted. The methods and processes described herein are also not limited to any particular order, and the blocks or states associated therewith may be executed in other suitable orders. For example, the described blocks or states may be executed in an order different from the specifically disclosed order, or multiple blocks or states may be combined into a single block or state. Example blocks or states may be executed serially, in parallel, or otherwise. Blocks or states may be added or removed from the disclosed example embodiments. The example systems and components described herein may be configured differently than described. For example, elements may be added, removed, or rearranged compared to the disclosed example embodiments.

[0071] Unless otherwise expressly stated or otherwise understood in the context of use, conditional language such as "can," "could," "might," or "may" is generally intended to convey that certain embodiments include certain features, elements, and / or steps, while other embodiments do not include certain features, elements, and / or steps. Thus, such conditional language is generally not intended to imply that the features, elements, and / or steps are in any way required for one or more embodiments or that one or more embodiments necessarily include logic for determining whether these features, elements, and / or steps are included or are to be performed in any particular embodiment (whether or not there is user input or prompting).

[0072] Any process descriptions, elements, or blocks in the flowcharts described herein and / or shown in the flowcharts of the figures should be understood as possibly representing modules, segments, or portions of code that include one or more executable instructions for implementing specific logical functions or steps in the process. Alternative implementations are included within the scope of the embodiments described herein, where elements or functions may be deleted according to the involved functions, and elements or functions may be executed in an order inconsistent with the order shown or discussed, including executing elements or functions substantially simultaneously or in the reverse order, as understood by those skilled in the art.

[0073] It should be emphasized that many variations and modifications can be made to the above embodiments, and the elements of these variations and modifications should be understood to belong to other acceptable examples. All such modifications and variations are intended to be included within the scope of the present disclosure herein. The above description details certain embodiments of the present disclosure. However, it can be understood that, no matter how detailed the above content is described, this concept can be practiced in various ways. As mentioned above, it should be noted that the use of specific terms when describing certain features or aspects of the present disclosure should not be construed as implying that the term is redefined herein to be limited to any specific features including the features or aspects of the present disclosure related to the term. Therefore, the scope of protection should be construed in accordance with the appended claims and their equivalents.

Claims

1. A method for calibrating a positioning system, comprising: Sending a calibration signal from a calibration device located at a first known position; Receiving, by the calibration device, a reflection of the calibration signal from a positioning element located at a second known position, wherein the reflection carries identification information of the positioning element; Analyzing characteristics of the reflection using the first known position and the second known position to determine reflection characteristics of the positioning element; Storing calibration information including the reflection characteristics of the positioning element for use in the process of positioning a user equipment.

2. The method according to claim 1, wherein The reflection characteristic is a phase shift.

3. The method according to claim 1, wherein The reflection characteristic is a reflection loss.

4. The method according to any one of the preceding claims, further comprising: Sending data indicating the characteristics of the reflection or the reflection characteristics from the calibration device to a server, wherein storing the calibration information includes storing the calibration information on the server.

5. The method according to any one of claims 1 to 4, wherein Storing the calibration information includes locally storing the calibration information on the calibration device.

6. The method according to any one of the preceding claims, wherein, The calibration device is a fixed device.

7. The method according to any one of claims 1 to 5, wherein, The calibration device is a mobile device.

8. The method according to claim 7, wherein The calibration device is a user equipment UE.

9. The method according to any one of the preceding claims, wherein The positioning element is an ambient power tag.

10. The method according to any one of the preceding claims, further comprising: Determining a confidence level of the determined reflection characteristics of the positioning element.

11. The method according to claim 10, wherein, The confidence level is determined based on one or more of the following: The signal strength of the reflection; The signal strength difference between multiple reflections; or The time when the reflection is received.

12. A method for positioning a user equipment, comprising: Sending a positioning signal from the user equipment to a plurality of positioning elements, each positioning element having a known position; Receiving, at the user equipment, a reflection of the positioning signal from the positioning element, wherein each reflection of the positioning signal carries identification information of the positioning element that reflects the positioning signal; Calculating a distance between the user equipment and the positioning element based on characteristics of the received reflection from the positioning element and calibration information obtained by the method according to any one of claims 1 to 11; Identifying the position of the user equipment based on the calculated distance and the known positions.

13. The method according to claim 12, wherein, The step of identifying the position of the user equipment is performed on the user equipment.

14. The method according to claim 12, wherein, The step of identifying the position of the user equipment is performed on the server.

15. A calibration system includes a calibration device located at a first known position and a positioning element located at a second known position, wherein, The system is configured to: Send a calibration signal from the calibration device; Receive, by the calibration device, a reflection of the calibration signal from the positioning element, wherein the reflection carries identification information of the positioning element; Analyze characteristics of the reflection using the first known position and the second known position to determine reflection characteristics of the positioning element; Store calibration information including the reflection characteristics of the positioning element for use in the process of positioning a user equipment.

16. The system according to claim 15, wherein, The reflection characteristic is a phase shift.

17. The system according to claim 15, wherein The reflection characteristic is a reflection loss.

18. The system according to any one of claims 15 to 17 further includes a server, wherein, The calibration device is configured to send data indicating the characteristics of the reflection or the reflection characteristics to the server; The calibration information is stored on the server.

19. The system according to any one of claims 15 to 17, wherein, The calibration information is locally stored on the calibration device.

20. The system according to any one of claims 15 to 19, wherein, The calibration device is a fixed device.

21. The system according to any one of claims 15 to 20, wherein, The calibration device is a mobile device.

22. The system according to claim 21, wherein, The calibration device is a user equipment UE.

23. The system according to any one of claims 15 to 22, wherein, The positioning element is an ambient power tag.

24. The system according to any one of claims 15 to 23, wherein The positioning device is a radio frequency identification tag.

25. The system according to any one of claims 15 to 24, further configured to determine a confidence level of the determined reflection characteristics of the positioning element.

26. The system according to claim 25, wherein, The confidence level is determined based on one or more of the following: The signal strength of the reflection; The signal strength difference between multiple reflections; or The time at which the reflection is received.

27. A positioning system for positioning a user device, comprising the user device and a plurality of positioning elements, wherein the plurality of positioning elements include the positioning elements described in any one of claims 15 to 26. The positioning system is configured to: Send a positioning signal from the user equipment to the plurality of positioning elements, each positioning element having a known position; Receive, at the user equipment, a reflection of the positioning signal from the positioning element, wherein each reflection of the positioning signal carries identification information of the positioning element that reflected the positioning signal; Calculate a distance between the user equipment and the positioning element based on characteristics of the received reflection from the positioning element and calibration information stored in the system according to any one of claims 15 to 26; Identify the position of the user equipment based on the calculated distance and the known position.

28. The system according to claim 27, the system being configured to identify the position of the user equipment at the user equipment.

29. The system according to claim 27, the system being configured to identify the position of the user equipment at the server.

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