Patent Description:
With the development of the times, the mobile phone positioning technology has drawn more and more attentions. However, all of the currently used positioning technologies, such as a Global Positioning System (GPS) positioning technology, a wireless sensor network-based positioning technology, or other positioning means, have their respective limits. In order to achieve higher positioning accuracy, combination of multiple positioning systems for cooperative positioning (also called multimode positioning) is a direction for future development. Multimode positioning can utilize advantages of various positioning methods to achieve higher positioning accuracy and response speed and also cover a wider range to implement seamless and accurate positioning.

For example, a satellite positioning system and a mobile communication system are organically combined for mobile phone positioning. Advantages of large coverage area and high open space positioning accuracy of the satellite positioning system and high indoor and dense urban area positioning accuracy of a mobile communication network are fully utilized, so that a market requirement is better met.

It is known that, as shown in <FIG>, positioning with a satellite positioning system is implemented by finding at least four satellites, then performing distance measurement according to time of arrival, listing at least three spherical equations or hyperbolic equations according to distances and obtaining a current position for positioning in a manner of resolving the equations.

However, in an indoor circumstance or a dense urban area, a GPS signal is highly attenuated, so that four satellites may not be completely found, GPS positioning may not be implemented, and a positioning function is restricted.

Usually, a coverage environment of a cellular network in a dense urban area and an indoor condition is obviously superior to a satellite signal, but the problem of inaccuracy of cellular positioning exists because of factors of Non Line Of Sight (NLOS), multiple paths and the like. Regarding this problem, researchers in this field have obtained some research results, but these research results are obtained on the basis of ideal assumptions, and are industrially infeasible in terms of accurate positioning. Therefore, a feasible wireless positioning method capable of providing an accurate positioning capability during a practical application is urgent to be further deeply researched and provided.

Document D1 (XP <NUM>) discloses "Accurate indoor Positioning Using Multipath Components". Document D2 (XP031812020) discloses "UWB positioning with virtual anchors and floor plan information". Document D3 (<CIT>) discloses a method and system for determining the position of a mobile device. Document D4 (<CIT>) discloses a positioning method and device based on calibration point. Document D5 (<CIT>) discloses a position determination system and apparatus for utilizing a network of cellular base station to determine position of a mobile station. Document D6 (<CIT>) disclose a method for evaluating angle of radiation source. Document D7 (<CIT>) discloses position determination using almanac for virtual base stations. Document D8 (<CIT>) discloses a method for determination of wireless terminals positions and associated system and an apparatus therof.

In order to provide a feasible wireless positioning method capable of providing an accurate positioning capability during a practical application, the embodiments of the present disclosure provide a virtual anchor point-based wireless positioning method and device, and a terminal.

The present disclosure is defined by appended independent claims, the dependent claims constitute embodiment of the invention; any other embodiment of the description not covered by the appended claims is to be considered as not being part of the present disclosure.

From the technical solutions of the embodiments of the present disclosure, the virtual anchor point-based wireless positioning method and device, and the terminal provided by the present disclosure, compared with a related art, at least have the following beneficial effects.

According to the embodiments of the disclosure, multiple positioning methods are integrated, and in a rich multipath scenario (for example, an indoor environment and a dense urban area), continuously recorded virtual anchor points of multiple paths of a practical wireless signal transmission station are combined with another effective positioning condition for positioning, so that multipath information is fully utilized, positioning errors caused by signal reflection and diffraction are reduced, and in addition, the problem of insufficient effective positioning anchor points is solved.

Achievement of the purpose, function characteristics and good effects of the present disclosure will be further described below with reference to specific embodiments and the drawings.

The technical solutions of the present disclosure will be further described below with reference to the drawings and specific examples in detail to make those skilled in the art better understand and implement the present disclosure, but the enumerated examples are not intended to limit the present disclosure.

A core idea of the technical solution provided in the examples of the present disclosure is to implement wireless positioning in a complex wireless multipath environment such as an indoor environment and a dense urban area through virtual anchor points on the basis of multipath tracking and identification. A virtual anchor point of a real anchor point refers to a position of a virtual signal transmission source after a receiver supposes that a signal is linearly transmitted and is not diffracted and reflected after the signal transmitted by the real anchor point is received by the receiver. <FIG> shows a schematic diagram of a practical virtual image during reflection propagation of an electromagnetic wave, and as shown in <FIG>, a wireless signal transmitted by a signal transmission source S reaches terminal <NUM> or <NUM> after being reflected by a reflector, and if a reflecting surface of the reflector does not change, a position S' of a virtual image of the signal transmission source S (anchor point) relative to terminal <NUM> or <NUM> is kept unchanged. A positioning method in the related art uses a real anchor point position coordinate and solves a distance equation to obtain a position of terminal <NUM> or <NUM>, and the inventor of the present disclosure discovers that a positioning result obtained by such a method in the related art may have a great error under the condition that the signal is reflected greatly.

In addition, according to the examples of the present disclosure, a terminal may also be positioned according to a virtual image if a diffraction point is far away from the terminal to be positioned under the condition of existence of diffraction. As shown in <FIG>, a signal of a base station is sequentially diffracted and reflected to reach the terminal, a position, calculated by the terminal, of a virtual image may be automatically regulated to be farer, and in case of a long distance, a change in the virtual image is observed to be small when the mobile terminal moves. Moreover, the signal is reflected for many times, and the position of the virtual image may not change along with movement of the terminal to be positioned. Referring to <FIG>, under the condition of multiple propagation paths, a received signal is an envelope in a time domain, and time differences among signal envelopes are caused by different propagation path distances. According to the examples of the present disclosure, a position of a terminal is calculated and determined by virtue of a position of a virtual image of an anchor point, so as to reduce the problem of positioning error caused by multipath reflection.

Referring to <FIG>, an example of the present disclosure provides a virtual anchor point-based wireless positioning method, which includes:.

For example, in the example of the present disclosure, for Step S10, a method for a signal receiving station (such as User Equipment (UE), the UE may be in a moving or still state) to acquire the positioning data may be implemented as follows:
if the signal receiving station can find sufficient satellites, a position calculation method the same as that of the signal transmission station is used, and if the signal receiving station uses integration information of satellite and virtual anchor point, then:.

In the example, for Step S10, when the effective positioning condition is met, acquiring and storing the positioning data includes, acquiring the positioning data through satellite positioning or acquiring the positioning data through cellular positioning of a mobile communication system.

In an example example, the positioning data may include positioning time information and position information.

For Step S10, a method for performing multipath analysis and tracking on the received wireless signals transmitted by the signal transmission station is implemented as follows:
the received multipath signals are separated by a signal analysis technology, the multipath signals are continuously tracked in a time domain, and if an existence time length of a single path is lower than a preset time length threshold and/or signal strength of the single path is lower than a preset signal strength threshold, tracking of the single path is stopped.

For Step S10, after multipath analysis and tracking is performed on the received wireless signals transmitted by the signal transmission station, a method for calculating and storing the propagation distance information of each path of the signal transmission station is implemented as follows:.

For Step S10, when the virtual image position information of each path of the signal transmission station is calculated according to the positioning data and the propagation distance information of each path of the signal transmission station, real position information of the signal transmission station may be acquired in advance, wherein a method for acquiring the real position information of the signal transmission station may include, but not limited to:.

In the example of the present disclosure, a method for the signal transmission station to acquire the real position information by at least one method is implemented as follows:
the space coordinate of the signal transmission station is set to be (α,x,y,z), wherein α represents a timing difference between the signal transmission station and the satellite, and x, y and z represent the space coordinate of the signal transmission station; the signal transmission station may find at least <NUM> GPS satellites and measure distances di between the signal transmission station and the at least <NUM> satellites. An equation set is listed according to spherical equations, and the coordinate of the signal transmission station is solved; or subtraction is performed on the distances between the signal transmission station and the two satellites, a hyperbolic equation set is listed, and the coordinate of the signal transmission station is solved.

For Step S10, a method for calculating the virtual image position information of each path of the signal transmission station according to the positioning data and the propagation distance information of each path of the signal transmission station includes:.

In Step S20, for example, whether the current effective positioning condition is met or not may be judged in a manner as follows:.

For Step S20, when the effective positioning condition is not met, bases for selecting the at least one virtual image from the virtual images of the multiple paths of the signal transmission station as the at least one positioning virtual anchor point are that:.

For Step S20, when the current position information is obtained according to the effective positioning condition and the at least one positioning virtual anchor point, the at least one positioning virtual anchor point may be at least one selected positioning virtual anchor point of which signal strength exceeds a fourth preset threshold.

In order to better describe the principle of the examples of the present disclosure, specific examples about application of the technical solution provided by the examples of the present disclosure to a mine, an indoor environment and a dense urban area will be enumerated.

As shown in <FIG>, in the mine, one piece of UE moves from position S1 to S2, and it is supposed that there are <NUM> satellites in the sky.

According to a satellite navigation positioning algorithm in the related art, at least <NUM> satellite signals are required to be received for positioning. In the example:
when the UE is at position S1:
the UE can receive signals of totally <NUM> satellites GPS1, GPS2, GPS3 and GPS4, and meets an independent positioning condition, and positioning information is set to be (α, x1, y1, z1), wherein α is a time difference of a clock of the signal receiving station and the satellites, and x1, y1 and z1 are three-dimensional coordinates respectively.

The UE can simultaneously receive signals of <NUM> paths of base station Bs1, i.e., the UE can receive a signal of direct transmission path P11 of base station Bs1 and a signal of P12 reflected by a surface.

The UE can simultaneously receive signals of <NUM> paths of base station Bs2, i.e., the UE can receive a signal of direct transmission path P21 of base station Bs2 and a signal of P22 reflected by the surface.

When the UE moves from position S1 to position S2, namely gradually moves from a wellhead to a deep part of a well, the number of the found satellites is gradually reduced along with movement, and only the satellite signal of G2 can be found at S2; and along with movement, the signal of P11 of Bs1 is also gradually weakened and the signal of P21 of Bs2 is also gradually weakened because of lack of direct transmission condition.

When reaching S2, the UE can only find the signal of G2, the signal of P12 of Bs1 and the signal of P22 of Bs2.

At the wellhead, the UE can be positioned through the satellite, and a positioning coordinate of UE1 is continuously recorded.

Since the UE can simultaneously receive the signals of the two paths of Bs1, the UE continuously measures and records propagation distances of the signals of the two paths.

A position and a distance are extracted from the latest position records and path propagation distance records of the UE, a spherical equation is listed and solved to obtain and continuously record a position of a virtual image Bs1', propagated through P12, of Bs1, and since a reflecting surface changes a little, the position of Bs1' changes a little in a movement process of the UE in the example.

Since the UE can simultaneously receive the signals of the two paths of Bs2, the UE continuously measures and records propagation distances of the signals of the two paths.

A position and a distance are extracted from the latest position records and path propagation distance records of the UE, a spherical equation is listed and solved to obtain and continuously record a position of a virtual image Bs2', propagated through P22, of Bs2, and since a reflecting surface changes a little, the position of Bs2' changes a little in a movement process of the UE in the example.

When the UE moves to S2, the UE can receive only one satellite, so that virtual images Bs1' and Bs2' are selected as virtual anchor points.

A coordinate of the UE is set to be (x, y, z).

According to positions and distances between UE1 and three anchor points G2, Bs1' and Bs2', a distance equation is listed, and the coordinate of the UE is solved.

As shown in <FIG>, in an indoor environment, one piece of UE1 moves from position S1 to S2, and it is supposed that there are <NUM> satellites in the sky.

According to a satellite navigation positioning algorithm in the related art, at least <NUM> satellite signals are required to be received for positioning. In the example:
when UE1 is at position S1:
UE1 can receive signals of totally <NUM> satellites GPS1, GPS2, GPS3 and GPS4, and meets an independent positioning condition, and positioning information is set to be (α, x1, y1, z1), wherein α is a time difference of a clock of UE1 and the satellites, and x1, y1 and z1 are three-dimensional coordinates respectively.

UE1 can simultaneously receive signals of <NUM> paths of base station Bs1, i.e., the UE can receive a signal of direct transmission path P11 of base station Bs1 and a signal of P12 reflected by a surface.

When UE1 moves from position S1 to position S2, namely gradually moves from a door deep into the inside of the room, the number of the found satellites is gradually reduced along with movement, and only the satellite signal of G4 can be found at S2; and along with movement, the signal of P11 of Bs1 is also gradually weakened because of lack of direct transmission condition.

When reaching S2, UE1 can only find the signal of G2 and the signal of P12 of Bs1.

UE1 can be positioned through the satellite outdoors, and a positioning coordinate of UE1 is continuously recorded.

Since UE1 can simultaneously receive the signals of the two paths of Bs1, UE1 continuously measures and records propagation distances of the signals of the two paths.

A position and a distance are extracted from the latest position records and path propagation distance records of UE1, a spherical equation is listed and solved to obtain and continuously record a position of a virtual image Bs1', propagated through P12, of Bs1, and since a reflecting surface changes a little, the position of Bs1' changes a little in a movement process of UE1 in the example.

When UE1 moves to S2, UE1 can only receive one satellite and path P12, so that virtual image Bs1' is selected as a virtual anchor point.

According to a building map, a coordinate of UE1 may be set to be (x, y) in a horizontal plane inside the room.

According to positions and distances of UE1 and two anchor points G2 and Bs1', a distance equation is listed, and the coordinate of UE1 is solved.

As shown in <FIG>, when surrounded by buildings, one piece of UE moves from position S1 to S2, and it is supposed that there are <NUM> satellites in the sky.

According to a satellite navigation positioning algorithm in the related art, at least <NUM> satellite signals are required to be received for positioning. In the example:
when the UE is at position S1:
the UE can receive signals of totally <NUM> satellites GPS1, GPS2, GPS3 and GPS4, and meets an independent positioning condition, and positioning information is set to be (α, x1, y1, z1), wherein α is a time difference of a clock of the UE and the satellites, and x1, y1 and z1 are three-dimensional coordinates respectively.

The UE can simultaneously receive signals of <NUM> paths of base station Bs1, i.e., the UE can receive a signal of P12, reflected by a surface, of Bs1.

When the UE moves from position S1 to position S2, namely gradually moves to a shadow area of the building, the number of the found satellites is gradually reduced along with movement, and the satellite signal of G4 may not be found at S2; and the signal of P12 of Bs1 can be found all the time in a movement process.

When reaching S2, the UE may find the signals of GPS1, GPS2 and GPS3 and the signal of P12 of Bs1.

At S1, the UE can be positioned through the satellites, and a positioning coordinate of the UE is continuously recorded.

Since the UE can simultaneously receive the signal of P12 of Bs1, the UE continuously measures and records propagation distances of the signal.

When the UE moves to S2, the UE can only receive the signals of one satellite and P12, so that virtual image Bs1' is selected as a virtual anchor point.

According to a building map, the coordinate of the UE may be set to be (x, y) in a horizontal plane in the current environment.

According to positions and distances of the UE and two anchor points G2 and Bs1', a distance equation is listed, and the coordinate of the UE is solved.

As shown in <FIG>, an example of the present disclosure further provides a virtual anchor point-based wireless positioning device <NUM>, which includes:.

In the example, when the effective positioning condition is met, a method for the position calculation module <NUM> to acquire and store the positioning data includes, but not limited to: acquiring the positioning data through satellite positioning or acquiring the positioning data through cellular positioning of a mobile communication system.

Wherein the positioning data includes positioning time information and position information.

In the example, referring to <FIG>, the multipath separation and tracking module <NUM> includes:.

In the example, referring to <FIG>, the multipath distance measurement module <NUM> includes:.

In the example, still referring to <FIG>, the multipath distance measurement module further includes:.

In the example, referring to <FIG>, the virtual anchor point processing module <NUM> includes:.

In the example, when the effective positioning condition is not met, bases for the virtual anchor point selection module <NUM> to select the virtual image from the virtual images of the multiple paths of the signal transmission station <NUM> as the positioning virtual anchor point are that:.

In the example, when the position calculation module <NUM> obtains the current position information according to the effective positioning condition and the at least one positioning virtual anchor point, the at least one positioning virtual anchor point is at least one selected positioning virtual anchor point of which signal strength exceeds a fourth preset threshold.

An example of the present disclosure further correspondingly provides a terminal, which includes the abovementioned virtual anchor point-based wireless positioning device <NUM>, still referring to <FIG>, the virtual anchor point-based wireless positioning device <NUM> including:.

Detailed description about the virtual anchor point-based wireless positioning device <NUM> may refer to the above, and will not be elaborated herein.

The above is only the examples of the present disclosure and thus not intended to limit the scope of patent of the present disclosure, and any equivalent structure or equivalent flow transformation made by virtue of contents of the Specification and drawings of the present disclosure or direct or indirect application of the contents to other related technical fields shall fall within the scope of protection of the present disclosure.

The technical solutions provided by the embodiments of the present disclosure may be applied to a virtual anchor point-based wireless positioning process. According to the embodiments of the present disclosure, multiple positioning methods are integrated, and in a rich multipath scenario (for example, an indoor environment and a dense urban area), continuously recorded virtual anchor points of multiple paths of a practical wireless signal transmission station are combined with another effective positioning condition for positioning, so that multipath information is fully utilized, positioning errors caused by signal reflection and diffraction are reduced, and in addition, the problem of insufficient effective positioning anchor points is solved.

According to a satellite navigation positioning algorithm in the related art, at least <NUM> satellite signals are required to be received for positioning. In the embodiment:
when the UE is at position S1:
the UE can receive signals of totally <NUM> satellites GPS1, GPS2, GPS3 and GPS4, and meets an independent positioning condition, and positioning information is set to be (α, x1, y1, z1), wherein α is a time difference of a clock of the UE and the satellites, and x1, y1 and z1 are three-dimensional coordinates respectively.

A position and a distance are extracted from the latest position records and path propagation distance records of the UE, a spherical equation is listed and solved to obtain and continuously record a position of a virtual image Bs1', propagated through P12, of Bs1, and since a reflecting surface changes a little, the position of Bs1' changes a little in a movement process of the UE in the embodiment.

As shown in <FIG>, an embodiment of the present disclosure further provides a virtual anchor point-based wireless positioning device <NUM>, which includes:.

In the embodiment, when the effective positioning condition is met, a method for the position calculation module <NUM> to acquire and store the positioning data includes, but not limited to: acquiring the positioning data through satellite positioning or acquiring the positioning data through cellular positioning of a mobile communication system.

In the embodiment, referring to <FIG>, the multipath separation and tracking module <NUM> includes:.

In the embodiment, referring to <FIG>, the multipath distance measurement module <NUM> includes:.

In the embodiment, still referring to <FIG>, the multipath distance measurement module further includes:.

In the embodiment, referring to <FIG>, the virtual anchor point processing module <NUM> includes:.

In the embodiment, when the effective positioning condition is not met, bases for the virtual anchor point selection module <NUM> to select the virtual image from the virtual images of the multiple paths of the signal transmission station <NUM> as the positioning virtual anchor point are that:.

In the embodiment, when the position calculation module <NUM> obtains the current position information according to the effective positioning condition and the at least one positioning virtual anchor point, the at least one positioning virtual anchor point is at least one selected positioning virtual anchor point of which signal strength exceeds a fourth preset threshold.

An embodiment of the present disclosure further correspondingly provides a terminal, which includes the abovementioned virtual anchor point-based wireless positioning device <NUM>, still referring to <FIG>, the virtual anchor point-based wireless positioning device <NUM> including:.

The above is only the example embodiment of the present disclosure and thus not intended to limit the scope of patent of the present disclosure.

Claim 1:
A virtual anchor point-based wireless positioning method, comprising:
when an effective positioning condition is met, acquiring positioning data through satellite positioning and and storing the positioning data, simultaneously performing multipath analysis and tracking on received wireless signals transmitted by a signal transmission station (<NUM>), calculating and storing propagation distance information of each path of the signal transmission station (<NUM>), and calculating and storing virtual image position information of each path of the signal transmission station (<NUM>) according to the positioning data and the propagation distance information of each path of the signal transmission station (<NUM>), wherein the effective positioning condition is met is that the number of found satellites is more than or equal to four; and
when the effective positioning condition is not met, selecting at least one virtual image from virtual images of multiple paths of the signal transmission station (<NUM>) as at least one positioning virtual anchor point, and obtaining current position information according to the found satellites and the at least one positioning virtual anchor point, wherein the effective positioning condition is not met is that the number of the found satellites is smaller than four;
wherein calculating the virtual image position information of each path of the signal transmission station (<NUM>) according to the positioning data and the propagation distance information of each path of the signal transmission station (<NUM>) comprises: selecting, from storage records of the positioning data, at least three pieces of positioning data of which effective position differences are greater than a first preset threshold; extracting the corresponding path propagation distance information from storage records of the path propagation distances according to time indexes of the positioning data; and calculating a virtual image position of each path of the signal transmission station (<NUM>) according to the positioning data and the path propagation distances.