Fast positioning method and device for indoor scene based on millimeter wave large-scale planar array direction angle measurement

Abstract

The application discloses a fast positioning method and device of an indoor scene based on a millimeter wave large-scale planar array direction angle measurement, which processes millimeter wave signals containing two-dimensional azimuth angle information received by a planar array, transforms the received signals into a two-dimensional frequency domain, performs autocorrelation operation on the transformed signals to obtain total energy of the frequency domain signals, performs beam screening on each beam in the transformed two-dimensional frequency domain to obtain a total number of screened beams, estimates two-dimensional azimuth angles in horizontal and vertical directions according to the screened beams, estimates whether there is a line-of-sight communication according to the energy of the screened beams, estimates a path number of multipath signals corresponding to the screened beams, and performs fast positioning of the indoor scene according to the estimation result of the two-dimensional azimuth angles. The application can realize fast measurement of azimuth angles of a large-scale planar array of a wideband millimeter wave channel and simple indoor positioning.

Description

Technical Field

[0001] This invention belongs to the field of wireless communication technology, specifically relating to a rapid positioning method and device for indoor scenes based on millimeter-wave large-scale planar array orientation angle measurement. Background Technology

[0002] With the rapid growth in the number of mobile communication network terminal users, the increasing richness of network information content, and the more frequent use of internet-enabled devices, accurate and low-cost positioning of mobile devices in environments with weak or unavailable Global Positioning System (GPS) signals, such as indoors and in the suburbs, has become a necessity in next-generation wireless communication systems. Massive MIMO (Massively Multi-Tap) technology can utilize the spatial degrees of freedom provided by multiple antennas to achieve spatial diversity and multiplexing gain, significantly improving network spectral efficiency without increasing bandwidth or transmit power. Furthermore, due to the high directivity of massive MIMO, it also possesses the capability for precise positioning of wireless targets.

[0003] Unlike traditional cellular networks, millimeter-wave communication boasts abundant frequency band resources. Due to the short wavelength characteristics of millimeter-wave signals, a large number of antennas can be integrated into a small area when designing array antennas. However, due to the high path loss of millimeter-wave signals, the link quality is inferior to that of low-frequency communication. To compensate for the poor link quality of millimeter-wave communication and overcome the size limitations of configuring multi-antenna structures for small devices, massive MIMO technology can be combined with millimeter waves. This will fully utilize the advantages of both technologies, making precise wireless positioning possible using small-scale antenna devices.

[0004] However, existing technologies for measuring spatial azimuth mostly require eigenvalue decomposition or global search methods, which are complex and difficult to implement. Furthermore, the large number of antenna elements used in large-scale array antennas for direction measurement significantly limits the application of this technology in practical communication systems. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to address the shortcomings of the prior art by providing a rapid positioning method and apparatus for indoor scenes based on the measurement of azimuth angle of a large-scale planar array using millimeter-wave technology. This method is used for rapid measurement of the azimuth angle of a large-scale planar array using a broadband millimeter-wave channel and for simple indoor positioning. By utilizing the characteristics of sparse multipath transmission of signals in a millimeter-wave multi-antenna system, the received signals are selected in the frequency domain based on beam energy to estimate the angle of the received signals, thereby achieving rapid and efficient accurate positioning of indoor wireless scenes. This overcomes the problems of high complexity and difficulty in implementation of the prior art when measuring azimuth angle.

[0006] To achieve the above-mentioned technical objectives, the technical solution adopted by the present invention is as follows:

[0007] A rapid localization method for indoor scenes based on millimeter-wave large-scale planar array orientation angle measurement includes:

[0008] Step 1: Process the millimeter-wave signal containing two-dimensional azimuth information received by the planar array, and transform the received signal into the two-dimensional frequency domain;

[0009] Step 2: Perform autocorrelation calculation on the signal obtained from the transformation in Step 1 to obtain the total energy of the frequency domain signal.

[0010] Step 3: Based on the total energy calculated in Step 2, perform beam filtering on each beam in the converted two-dimensional frequency domain to obtain the total number of filtered beams;

[0011] Step 4: Estimate the two-dimensional azimuth angles in the horizontal and vertical directions based on the selected beams;

[0012] Step 5: Determine whether line-of-sight communication exists based on the selected beam energy. If line-of-sight communication exists, the direction of the received signal is the estimated direction of the target. Otherwise, the target position can only be estimated through a non-line-of-sight path.

[0013] Step 6: Based on the number of beams selected in Step 3, estimate the number of multipath signals corresponding to the selected beams;

[0014] Step 7: Based on the estimation results of the two-dimensional azimuth angle in Step 4 and the relationship between the beam and the path in Step 6, estimate the target's location using the non-line-of-sight (reflection) path to perform rapid positioning of the indoor scene.

[0015] To optimize the above technical solution, the specific measures also include:

[0016] Step 1 above specifically includes:

[0017] 1) Let the two-dimensional asymmetric discrete Fourier transform matrix be... ;

[0018] 2) Assume the received signal containing two-dimensional azimuth information is ,use , will signal Transforming to the two-dimensional frequency domain, we obtain the signal y: y .

[0019] The and Specifically, it is expressed as follows:

[0020]

[0021] in, This represents the number of antenna array elements in the horizontal direction. This represents the number of beams in the frequency domain corresponding to the horizontal direction after conversion.

[0022]

[0023] in, This represents the number of antenna elements in the vertical direction. This represents the number of beams in the frequency domain corresponding to the vertical direction after conversion.

[0024] In step 2 above, the formula for calculating the total energy of the frequency domain signal is:

[0025]

[0026] Step 3 performs beam filtering on each beam in the converted two-dimensional frequency domain based on the relationship between total energy and beam energy, and obtains the total number of filtered beams.

[0027] The relationship between the total energy and the beam energy is as follows:

[0028]

[0029] in, The energy of each beam, The ordinal number of the beam;

[0030] The total number of beams in the converted frequency domain is calculated using the following formula:

[0031]

[0032] Step 3 above specifically includes:

[0033] 1) Let the set of all beam indices be... The selected beam number set is ;

[0034] 2) Based on the total beam energy calculated in step 2, select the beam with the highest energy in both the horizontal and vertical directions, from highest to lowest energy. Assume this beam corresponds to the following sequence number: ;

[0035] 3) Beam sequence Add to collection ,Right now: ;

[0036] 4) In the set Remove the selected beam order At this time, the beam number set is ;

[0037] 5) Calculate the set The beam energy corresponding to the included beam number: ;

[0038] 6) and In comparison, among them, This indicates the line-of-sight distance and the proportion of total energy represented by a single reflection:

[0039] if If the filtering is complete, proceed to step 4.

[0040] if Then in the updated beam ordinal set The beam with the highest energy at that moment was selected from the samples, and its corresponding sequence number is [number missing]. ;

[0041] 7) Repeat steps 4) to 6) above until... ,in This indicates the total number of beams selected.

[0042] Step 4 above specifically refers to:

[0043] 1) Let the angles of the received multipath signal in the horizontal and vertical directions be respectively... and ,in, Indicates the number of paths;

[0044] 2) The normalized beam angles in the horizontal and vertical directions are respectively , :

[0045]

[0046]

[0047] in, For carrier frequency, At the speed of light, and Antenna spacing in the horizontal and vertical directions;

[0048] 3) Select the ordinal numbers of the beam in the horizontal and vertical directions according to the following relationship:

[0049]

[0050]

[0051] 4) Based on the ordinal numbers of the selected beams in the horizontal and vertical directions, estimate the angles of the received multipath signals in the horizontal and vertical directions. and .

[0052] Step 5 above involves selecting the beam energy in the first step. With the second selected beam energy In comparison, determining whether line-of-sight communication exists is crucial. Since the energy of line-of-sight signals in millimeter-wave communication is much greater than that of non-line-of-sight signals, if the energy of the first selected beam is much greater than that of the second selected beam, then the first selection is considered to be line-of-sight communication. If line-of-sight communication exists, it means that the transmitted signal is directly received by the receiver, and its signal direction is the target's azimuth. If line-of-sight communication does not exist, it means that the signal is received after being reflected or refracted, and the target's azimuth needs to be calculated using the reflection direction of the non-line-of-sight signal.

[0053] In step 6 above, the total number of beams selected in step 3 With the number of paths The following relationship exists:

[0054]

[0055] in, This is the channel dispersion factor of the communication system.

[0056] A rapid positioning device for indoor scenes based on millimeter-wave large-scale planar array orientation angle measurement, including a signal receiving terminal and a reflective surface;

[0057] The millimeter-wave signal transmitted by the signal transmitting device undergoes specular reflection when incident on the reflecting surface. The signal receiving terminal receives the reflected signal and estimates the azimuth angle of the multipath signal according to the method described above. The estimated azimuth angle of the multipath signal is then used to locate the signal transmitting device.

[0058] The aforementioned signal receiving terminal is a millimeter-wave multi-antenna device installed on the mobile vehicle 5.

[0059] The present invention has the following beneficial effects:

[0060] 1. The large-scale planar array azimuth measurement method of the present invention is applicable not only to broadband millimeter-wave communication scenarios, but also to narrowband microwave communication scenarios below 6 GHz, and has higher accuracy in narrowband systems;

[0061] 2. The large-scale planar array azimuth measurement method of the present invention has no restrictions on the shape and layout of the planar array, and therefore can be applied to communication systems configured with various planar arrays such as square arrays and circular arrays;

[0062] 3. In simple indoor environments, the positioning device of the present invention only requires one device to accurately locate wireless terminals in the scene, which is simple and has low complexity. Attached Figure Description

[0063] Figure 1 This is a flowchart of the rapid positioning method of the present invention;

[0064] Figure 2 This is a schematic diagram of the frequency domain beam energy distribution of the present invention;

[0065] Figure 3 This is a flowchart of the two-dimensional frequency domain beam filtering process of the present invention;

[0066] Figure 4 This is a schematic diagram illustrating the relationship between the channel dispersion factor and the frequency domain beam of this invention;

[0067] Figure 5 This is a geometric schematic diagram of the indoor positioning of the multi-antenna terminal of the present invention;

[0068] Figure 6 This is a schematic diagram of the indoor positioning scheme for the multi-antenna vehicle of the present invention;

[0069] Figure 7 This is a schematic diagram of the multi-antenna trolley structure of the present invention;

[0070] Figure 8 This is a schematic diagram of the indoor positioning geometry of the multi-antenna vehicle of the present invention;

[0071] Figure 9 This is the indoor positioning result of the multi-antenna vehicle of the present invention. Detailed Implementation

[0072] The embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0073] Example 1:

[0074] In this embodiment, see Figures 1-4 A rapid positioning method for indoor scenes based on millimeter-wave large-scale planar array azimuth angle measurement is proposed. This method utilizes the sparse multipath transmission characteristics of signals in millimeter-wave multi-antenna systems, filters beams based on beam energy in the frequency domain, estimates the angle of the received signal, is simple to implement, and is applicable to communication scenarios with various bandwidths.

[0075] Example 1 includes the following steps:

[0076] Step 1: See Figures 1-2 The millimeter-wave signal received by the planar array is processed directly using a two-dimensional asymmetric discrete Fourier transform, transforming the received signal into the two-dimensional frequency domain. The method is as follows:

[0077] 1) First, let's define a two-dimensional asymmetric discrete Fourier transform matrix. ,in and The asymmetric discrete Fourier transform matrices corresponding to the horizontal and vertical directions, respectively, can be expressed as:

[0078]

[0079] in, This represents the number of antenna array elements in the horizontal direction. This represents the number of beams in the frequency domain corresponding to the horizontal direction after conversion.

[0080] Structure and Similarly, it can be represented as follows:

[0081]

[0082] in, This represents the number of antenna elements in the vertical direction. This represents the number of beams in the frequency domain corresponding to the vertical direction after conversion.

[0083] 2) Assume the received signal containing two-dimensional azimuth information is Two-dimensional asymmetric discrete Fourier transform This can transform the signal to the frequency domain: y .

[0084] Step 2: Obtain the total energy E of the frequency domain signal by performing autocorrelation calculation on y:

[0085]

[0086] Since the total energy of the signal is the sum of the energies of each beam, the following relationship can be established:

[0087]

[0088] in, The ordinal number of the beam;

[0089] The total number of beams in the converted frequency domain can be calculated using the following formula:

[0090]

[0091] Step 3: See Figure 3 The beams in the converted two-dimensional frequency domain are selected based on their energy, as follows:

[0092] 1) Let the set of all beam indices be... The selected beam number set is .

[0093] 2) Based on the total beam energy calculated in step 2, select the beam with the highest energy in both the horizontal and vertical directions, from highest to lowest energy. Assume this beam corresponds to the following sequence number: .

[0094] 3) Select the beam sequence number Add to collection ,Right now: .

[0095] 4) In the set Remove the selected beam order At this time, the beam number set is .

[0096] 5) Calculate the set The beam energy corresponding to the included beam number: .

[0097] 6) and Comparison:

[0098] if Then the filtering is complete and the output is complete. Then proceed to step 4;

[0099] if Then in the updated beam ordinal set The beam with the highest energy at that moment was selected from the samples, and its corresponding sequence number is [number missing].

[0100] (in This indicates the line-of-sight distance and the proportion of total energy accounted for by the beam in a single reflection. In millimeter-wave multi-antenna systems, this proportion varies depending on the scenario. The value is typically between 0.6 and 0.9.

[0101] 7) Repeat steps 4) to 6) above until... ,in This indicates the total number of beams selected.

[0102] Step 4: See Figure 1 The two-dimensional azimuth angle is estimated based on the selected beams, as follows:

[0103] 1) Assume the angles of the received multipath signal in the horizontal and vertical directions are respectively... and ,in Indicates the number of paths.

[0104] 2) The normalized beam angles in the horizontal and vertical directions are respectively

[0105]

[0106] and

[0107]

[0108] in For carrier frequency, At the speed of light, and The antenna spacing is defined as the horizontal and vertical directions.

[0109] 3) Select the beam order in the horizontal and vertical directions according to the following relationship:

[0110]

[0111]

[0112] 4) Based on the ordinal numbers of the selected beams in the horizontal and vertical directions, the angles of the received multipath signals in the horizontal and vertical directions can be estimated. and .

[0113] Step 5: See Figure 1 The method for estimating the existence of line-of-sight communication is as follows:

[0114] 1) Based on the fast fading characteristics of millimeter wave signals, the beam energy corresponding to the line-of-sight path will be much greater than that of other beams; if a line-of-sight link exists, its corresponding beam will be selected first.

[0115] 2) By selecting the beam energy in the first round With the second selected beam energy In comparison, determining whether line-of-sight communication exists is crucial. Since the energy of line-of-sight signals in millimeter-wave communication is much greater than that of non-line-of-sight signals, if the energy of the first selected beam is much greater than that of the second selected beam, then the first selection is considered to be line-of-sight communication. If line-of-sight communication exists, it means that the transmitted signal is directly received by the receiver, and its signal direction is the target's azimuth. If line-of-sight communication does not exist, it means that the signal is received after being reflected or refracted, and the target's azimuth needs to be calculated using the reflection direction of the non-line-of-sight path.

[0116] Step 6: See Figure 1 , Figure 4 This invention is applicable to broadband communication systems and estimates the number of multipath signals in a selected beam. The method is as follows:

[0117] 1) Determine the number of beams selected in the communication system (especially the broadband communication system). With the number of paths The following relationship exists: , in This is the channel dispersion factor of the communication system.

[0118] 2) Based on the number of selected beams, the number of multipaths corresponding to the angle can be estimated.

[0119] That is, based on the number of beams selected in the communication system. With the number of paths Relationship: ;

[0120] in, This is the channel dispersion factor of the communication system.

[0121] For example: when When = 1, the number of beams is the same as the number of paths; when When the beam count is 3, the number of beams is three times the number of paths.

[0122] Step 7: Based on the estimation results of the two-dimensional azimuth angle in Step 4 and the relationship between the beam and the path in Step 6, first confirm the corresponding azimuth angles of each path in the horizontal and vertical directions. Then, using the transmission characteristics of millimeter wave near-optical, calculate the corresponding two-dimensional azimuth angles after reflection of each path based on the position of the radiating surface, so as to achieve rapid positioning of indoor scenes.

[0123] Example 2

[0124] A rapid positioning device for indoor scenes based on millimeter-wave large-scale planar array orientation angle measurement, in this embodiment, see [link to relevant documentation]. Figure 1 , Figure 5 The device uses only one signal receiving terminal 2. Under the condition of known indoor environment, based on the near-optical transmission characteristics of millimeter wave, the millimeter wave signal sent by the signal transmitting device 3 produces near-optical specular reflection when it is incident on the reflecting surface 4. According to the geometric relationship, the azimuth angle of the estimated multipath signal is used to locate the signal transmitting device 3.

[0125] Example 3

[0126] This embodiment is basically the same as embodiment 2, except that: in this embodiment, see... Figures 6-8By installing a millimeter-wave multi-antenna device on the mobile vehicle 5, indoor millimeter-wave wireless terminals can be located more quickly and efficiently. Specifically, this invention uses a fixed time slot to estimate the azimuth angle of the signal received at different positions during the movement of the multi-antenna vehicle 5. Simultaneously, utilizing the near-optical transmission characteristics of millimeter waves, and based on geometric relationships, the estimated azimuth angle of the multipath signal is used to locate the signal transmitting device 3.

[0127] The indoor millimeter-wave wireless positioning results of the multi-antenna vehicle used in this embodiment are shown in the attached image. Figure 9 As shown, where Figure 9 (a) and (b) represent the positioning results at signal-to-noise ratios of -15dB and 5dB, respectively. It can be seen that when using this invention to locate indoor wireless terminals, centimeter-level positioning accuracy can be achieved under conditions of high signal-to-noise ratio.

[0128] The above are merely preferred embodiments of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should be considered within the scope of protection of the present invention.

Claims

1. A rapid positioning method for indoor scenes based on millimeter-wave large-scale planar array orientation angle measurement, characterized in that, include: Step 1: Process the millimeter-wave signal containing two-dimensional azimuth information received by the planar array, and transform the received signal into the two-dimensional frequency domain; Step 2: Perform autocorrelation calculation on the signal obtained from the transformation in Step 1 to obtain the total energy of the frequency domain signal. Step 3: Based on the total energy calculated in Step 2, perform beam filtering on each beam in the converted two-dimensional frequency domain to obtain the total number of filtered beams, specifically including: 1) Let the set of all beam indices be... The selected beam number set is ; 2) Based on the total beam energy calculated in step 2, select the beam with the highest energy in both the horizontal and vertical directions, from highest to lowest energy. Assume this beam corresponds to the following sequence number: ; 3) Beam sequence Add to collection ,Right now: ; 4) In the set Remove the selected beam order At this time, the beam number set is ; 5) Calculate the set The beam energy corresponding to the included beam number: ; 6) and In comparison, among them, This indicates the line-of-sight distance and the proportion of total energy represented by a single reflection: if If the filtering is complete, proceed to step 4. if Then in the updated beam ordinal set The beam with the highest energy at that moment was selected from the samples, and its corresponding sequence number is [number missing]. ; 7) Repeat steps 4) through 6) above until... ,in This indicates the total number of beams selected; Step 4: Estimate the two-dimensional azimuth angles in the horizontal and vertical directions based on the selected beams; Step 5: Determine whether line-of-sight communication exists based on the selected beam energy. If line-of-sight communication exists, the direction of the received signal is the estimated direction of the target. Otherwise, the target position can only be estimated through a non-line-of-sight path. Step 6: Based on the number of beams selected in Step 3, estimate the number of multipath signals corresponding to the selected beams; Step 7: Based on the estimation results of the two-dimensional azimuth angle in Step 4 and the relationship between the beam and the path in Step 6, estimate the target's location using the non-line-of-sight path to perform rapid positioning of the indoor scene.

2. The rapid positioning method for indoor scenes based on millimeter-wave large-scale planar array orientation angle measurement according to claim 1, characterized in that, Step 1 specifically includes: 1) Let the two-dimensional asymmetric discrete Fourier transform matrix be... ; 2) Assume the received signal containing two-dimensional azimuth information is ,use , will signal Transforming to the two-dimensional frequency domain, we obtain the signal y: y .

3. The rapid positioning method for indoor scenes based on millimeter-wave large-scale planar array orientation angle measurement according to claim 2, characterized in that, The and Specifically, it is expressed as follows: in, This represents the number of antenna array elements in the horizontal direction. This represents the number of beams in the frequency domain corresponding to the horizontal direction after conversion. in, This represents the number of antenna elements in the vertical direction. This represents the number of beams in the frequency domain corresponding to the vertical direction after conversion.

4. The rapid positioning method for indoor scenes based on millimeter-wave large-scale planar array orientation angle measurement according to claim 1, characterized in that, In step 2, the formula for calculating the total energy of the frequency domain signal is: Step 3 performs beam filtering on each beam in the converted two-dimensional frequency domain based on the relationship between total energy and beam energy, and obtains the total number of filtered beams. The relationship between the total energy and the beam energy is as follows: in, The energy of each beam, The ordinal number of the beam; The total number of beams in the converted frequency domain is calculated using the following formula:

5. The rapid positioning method for indoor scenes based on millimeter-wave large-scale planar array orientation angle measurement according to claim 1, characterized in that, Step 4 specifically involves: 1) Let the angles of the received multipath signal in the horizontal and vertical directions be respectively... and ,in, Indicates the number of paths; 2) The normalized beam angles in the horizontal and vertical directions are respectively , : in, For carrier frequency, At the speed of light, and Antenna spacing in the horizontal and vertical directions; 3) Select the ordinal numbers of the beam in the horizontal and vertical directions according to the following relationship: 4) Based on the ordinal numbers of the selected beams in the horizontal and vertical directions, estimate the angles of the received multipath signals in the horizontal and vertical directions. and .

6. The rapid positioning method for indoor scenes based on millimeter-wave large-scale planar array orientation angle measurement according to claim 1, characterized in that, Step 5 involves selecting the beam energy in the first step. With the second selected beam energy In comparison, determining whether line-of-sight communication exists is crucial. Since the energy of line-of-sight signals in millimeter-wave communication is much greater than that of non-line-of-sight signals, if the energy of the first selected beam is much greater than that of the second selected beam, then the first selection is considered to be line-of-sight communication. If line-of-sight communication exists, it means that the transmitted signal is directly received by the receiver, and its signal direction is the location of the target. If line-of-sight communication does not exist, it means that the signal is received after being reflected or refracted, and the target position needs to be calculated using the reflection direction of the non-line-of-sight signal.

7. The rapid positioning method for indoor scenes based on millimeter-wave large-scale planar array orientation angle measurement according to claim 1, characterized in that, In step 6, the total number of beams selected in step 3 With the number of paths The following relationship exists: in, This is the channel dispersion factor of the communication system.

8. A rapid positioning device for indoor scenes based on millimeter-wave large-scale planar array orientation angle measurement, characterized in that, Includes the signal receiving terminal and the reflector; The millimeter-wave signal transmitted by the signal transmitting device undergoes specular reflection when incident on the reflecting surface. The signal receiving terminal receives the reflected signal and estimates the azimuth angle of the multipath signal according to any one of the methods described in claims 1-7. The signal transmitting device is located using the estimated azimuth angle of the multipath signal and the relationship between the beam and the path.

9. The rapid positioning device for indoor scenes based on millimeter-wave large-scale planar array orientation angle measurement according to claim 8, characterized in that, The signal receiving terminal is a millimeter-wave multi-antenna device installed on the mobile vehicle 5.

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