WO2015139181A1

WO2015139181A1 - Positioning method and positioning device

Info

Publication number: WO2015139181A1
Application number: PCT/CN2014/073540
Authority: WO
Inventors: 张阳; 刘劲楠; 王悦
Original assignee: 华为技术有限公司
Priority date: 2014-03-17
Filing date: 2014-03-17
Publication date: 2015-09-24
Also published as: CN105190349B; CN105190349A

Abstract

Disclosed are a positioning method and positioning device. The positioning method comprises: a receiving terminal receives known sequence signals from each transmitting end respectively; the receiving end conducts fast Fourier transform (FFT) on each known sequence signal and received signal respectively, first frequency domain signals being generated after conducting FFT on the known sequence signals and second frequency domain signals being generated after conducting FFT on the received signals; multiplying the second frequency domain signals by respective first frequency domain signals to obtain respective middle frequency domain signals; performing computation on respective middle frequency domain signals to obtain the time delays corresponding to respective middle frequency domain signals; according to the time delays, determining the location of the receiving end; during each iterative process, grouping the middle frequency domain signals and eliminating index values in a time domain until the iteration ends, determining the time delays in conjunction with the property of downsampling of an original domain and folding of a transform domain. The method and positioning device reduce the complexity in positioning.

Description

Positioning method and positioning device

Technical field

The present invention relates to the field of signal processing technologies, and in particular, to a positioning method and a positioning device. Background technique

In a conventional delay-based positioning method, multiple known locations of transmission points can transmit different known sequences to the ground at the same time, and these known sequences need to satisfy strong correlation, such as code division multiple access ( Code Division Multiple Access, CDMA) sequence. When a user receives a mixed signal composed of different known sequences sent by multiple transmitting points, the known sequence sent by different transmitting points is respectively mixed with the received signal received by the user, that is, a mixed signal of different known sequences. Convolution operation. Assuming that there is no channel and Gaussian noise interference, the result of the convolution is an impulse signal, which can be used to measure the delay of a certain transmission point to the user, and then the propagation point of the electromagnetic wave can be used to calculate the emission point to The distance of the user. When the distance from the multiple transmission points to the user is measured, the distance from each emission point to the user is the sphere centered on each emission point, and the intersection of all the spheres is the location of the user.

The complexity of the above positioning method mainly comes from the convolution operation of the known sequence and the received signal. Assuming that the length of the known sequence is n, the complexity of the convolution operation is O( ). The traditional localization method can reduce the complexity O(« ² ) of the original convolution operation to O(n log n) by multiplying the original domain convolution transformation domain.

In another existing positioning method, the nature of the frequency domain sampling time domain folding is utilized, and the complexity O(« ² ) of the original convolution operation is reduced to O(« i^). In this method, it is assumed that the sequence is known to be connected. The result of the convolution operation of the received signal is that there is only one index value with a large energy. In the actual system, since the received signal is affected by the multipath channel, the result of the convolution operation is the impulse response of the time domain channel. This assumption cannot be established.

Summary of the invention

technical problem

In view of this, the technical problem to be solved by the present invention is how to reduce the computational complexity of the positioning method in consideration of the influence of the multipath channel.

solution

In order to solve the above technical problem, in a first aspect, the present invention provides a positioning method, including:

The receiving end receives the known sequence signals from the respective transmitting ends respectively;

The receiving end performs a fast Fourier transform FFT on each of the known sequence signal and the received signal, where the received signal is a mixed signal formed by superposing each of the known sequence signals through channel fading, wherein The first frequency domain signal is obtained after the FFT of the known sequence signal, and the second frequency domain signal is obtained after the FFT of the received signal;

And multiplying the second frequency domain signal by each of the first frequency domain signals to obtain respective intermediate frequency domain signals;

Performing operations on the respective intermediate frequency domain signals to obtain delays corresponding to the respective intermediate frequency domain signals; determining the position of the receiving end according to the delay corresponding to each intermediate frequency domain signal.

With reference to the first aspect, in a first possible implementation manner of the first aspect, the calculating, by using the intermediate frequency domain signals, the delays corresponding to the respective intermediate frequency domain signals, including:

Performing an operation on the intermediate frequency domain signal, corresponding to obtaining a first set, the size of the first set is An order of magnitude of K, the first set consisting of consecutive index values of the intermediate frequency domain signal in the time domain, and Κ represents a maximum multipath delay of the channel;

Performing frequency domain downsampling on the intermediate frequency domain signal according to the sampling interval O, and performing an inverse fast Fourier transform IFFT on the downsampled result, corresponding to obtaining a second set, wherein the second set is obtained from the result of the IFFT Forming an index value sequentially taken in order of increasing energy, wherein the order of magnitude is the total length of the known sequence signal, which is a known positive integer;

And performing an intersection operation on the first set and the second set corresponding to the intermediate frequency domain signal, and determining a delay corresponding to the intermediate frequency domain signal according to a result of the intersection operation.

With reference to the first possible implementation manner of the first aspect, in a second possible implementation manner of the first aspect, the performing the operation on the intermediate frequency domain signal, corresponding to obtaining the first set, if the iterative condition is met , perform the following steps:

Performing a transform domain expansion on the intermediate frequency domain signal according to the first parameter, corresponding to obtaining an extended signal, wherein the transform domain is a time domain;

Performing a transform domain shift on the extended signal according to the second parameter, correspondingly obtaining a shift signal; dividing the shift signal into two groups according to an offline constructed frequency domain window function, and calculating energy of the two groups separately;

Determining an index value of the intermediate frequency domain signal in a time domain according to a magnitude relationship of the two packet energies;

The first parameter and the second parameter in the next iteration are calculated and it is determined whether the next iteration condition is satisfied.

In conjunction with the second possible implementation of the first aspect, the third possible implementation in the first aspect In the present mode, before the shifting signals are divided into two groups according to the frequency domain window function constructed offline, the method includes: using the formula V 2 sin c(2Q)exp

function;

Wherein, _G; window function to the frequency domain, for the pre-set parameters to represent the absolute error between the time-domain window function corresponding to the frequency domain over the time domain window function to the window function, j, ^ and " For the edge of the corresponding time domain window function

The ideal time domain window function includes a body portion, a side lobe portion and a remaining portion, wherein the main body score is 1, the width is ^, the side lobe portion value is less than 1, and the width is OW, that is, the order of w, remaining

^The score of 0 _{t is} combined with the second or third possible implementation of the first aspect. In the fourth possible implementation of the first aspect, the energy of the two packets is separately calculated, including:

And multiplying the shift signal by the frequency domain window function to obtain a product signal; respectively calculating, by using a discrete Fourier transform DFT, that the product signal has an index value of 0 in the time domain.

The first result and the second result of the index value; the calculated first result is

The second result is

Wherein, the first result is a value when the index value of the product signal in the time domain is 0; 2 is the second result, that is, a value when the index value of the product signal is in the time domain; The frequency domain window function; 0 is a time domain window function corresponding to the frequency domain window function; / is the shift signal; is a time domain signal corresponding to the shift signal; ^ is corresponding to the product signal Time domain signal; the first energy is ^. | ² , the second energy is μ „ _/2 ² .

In conjunction with the second or fourth possible implementation of the first aspect, in a fifth possible implementation manner of the first aspect, the intermediate frequency is excluded according to the magnitude relationship between the first energy and the second energy The index value of the domain signal in the time domain, including:

Comparing the magnitude relationship between the first energy and the second energy;

In ^. In the case of ² ≥| ₂ | ² , the index value of the shift signal in the time domain is excluded, and the set of the remaining values of the shift signal in the time domain is obtained as:

I. = 1 e {0,1,···«-1} and - /(mod n) e {0,1,· -·,η/ 4 + en)

The corresponding set of index values remaining in the time domain of the intermediate frequency domain signal is:

In ^. In the case of ² ≤| ₂ | ² , the index value of the shift signal in the time domain is excluded, and the set of the remaining values of the shift signal in the time domain is obtained as:

I _x = [ 1 ie {0,1,···«-1} and w/2- (mod n) e {0, 1, ···,«/ 4 + cw)

U {3w/4 - cn, 3n/4 -cn + l,---,n)

J ₁ = ij\aj-b (mod/i) G iA In conjunction with the second possible implementation of the first aspect, in a sixth possible implementation manner of the first aspect, if the intermediate frequency domain signal is excluded from the index value in the time domain, the remaining index values are configured. The first set of parameters and the second parameter in the next iteration are as follows:

The condition that the first parameter needs to satisfy is: σ is a positive odd number that is not 1, and σ ≤ _Μ , where Μ is the size of the set S;

The condition that the second parameter needs to satisfy is: -, where _m is the midpoint of the index value in the set S.

In conjunction with the second or sixth possible implementation of the first aspect, in a seventh possible implementation of the first aspect, the iteration is stopped if both of the following conditions are met:

|5|≤ cn;

It is calculated that the first parameter in the next iteration is the same as the first parameter in the previous iteration.

In conjunction with the first possible implementation of the first aspect, in an eighth possible implementation manner of the first aspect, the first set and the second set corresponding to the intermediate frequency domain signal are subjected to an intersection operation, and according to the intersection The result of the operation determines the delay corresponding to the intermediate frequency domain signal, including:

Determining an estimated index value according to a magnitude relationship of energy corresponding to the index value in the intersection operation result;

If the estimated index value is, the delay is nT _s , where 7: is the sampling period. In a second aspect, the present invention provides a positioning device comprising:

a receiving module, configured to respectively receive a known sequence signal from each transmitting end;

a transform module, coupled to the receiving module, for transmitting each of the known sequence signals and receiving The signals are respectively subjected to a fast Fourier transform FFT, and the received signal is a mixed signal obtained by superposing each of the known sequence signals by channel fading, wherein the FFT obtained by the known sequence signal is a first frequency domain. a signal, the FFT obtained after the received signal is a second frequency domain signal;

The transforming module is further configured to multiply the second frequency domain signal by each of the first frequency domain signals, and correspondingly obtain each intermediate frequency domain signal;

An operation module is connected to the transformation module, and is configured to perform operation on each intermediate frequency domain signal to obtain a delay corresponding to each intermediate frequency domain signal;

And a positioning module, configured to be connected to the computing module, configured to determine a location of the receiving end according to a delay corresponding to each intermediate frequency domain signal.

With reference to the second aspect, in a first possible implementation manner of the second aspect, the computing module includes:

a first unit, configured to perform an operation on the intermediate frequency domain signal, and correspondingly obtain a first set, where the size of the first set is an order of magnitude of K, and the first set is a continuous index of the intermediate frequency domain signal in a time domain Value composition, K represents the maximum multipath delay of the channel;

a second unit, connected to the first unit, configured to perform frequency domain downsampling on the intermediate frequency domain signal according to a sampling interval of 0 ("/^), and perform inverse fast Fourier transform IFFT on the downsampled result Correspondingly, obtaining a second set, wherein the second set is composed of index values sequentially taken out from the result of the IFFT according to the energy from large to small, wherein O is an order of magnitude of /, "for the known sequence signal The total length, which is a known positive integer;

a third unit, connected to the second unit, configured to perform an intersection operation on the first set and the second set corresponding to the intermediate frequency domain signal, and determine, according to a result of the intersection operation, the corresponding time of the intermediate frequency domain signal Delay. In conjunction with the first possible implementation of the second aspect, in a second possible implementation manner of the second aspect, the first unit further includes an expansion subunit, a shift subunit, a group subunit, and an exclusion subunit. , judging subunits, if the iteration condition is met,

The expansion subunit is configured to perform a transform domain expansion on the intermediate frequency domain signal according to the first parameter, and correspondingly obtain an extended signal, where the transform domain is a time domain;

The shifting subunit is connected to the expansion subunit, and is configured to perform a transform domain shift on the extended signal according to the second parameter, and correspondingly obtain a shift signal;

The grouping subunit is connected to the shifting subunit, and is configured to divide the shift signal into two groups according to a frequency domain window function configured offline, and calculate energy of two groups separately;

The exclusion subunit is connected to the grouping subunit, and is configured to exclude an index value of the intermediate frequency domain signal in a time domain according to the size relationship of the two packet energies;

The determining subunit is connected to the excluding subunit, and is configured to calculate the first parameter and the second parameter in the next iteration, and determine whether the next iteration condition is met.

In conjunction with the second possible implementation of the second aspect, in a third possible implementation of the second aspect, the grouping subunit is further configured to:

Function

Wherein, _G; window function to the frequency domain, for the pre-set parameters to represent the absolute error between the time-domain window function corresponding to the frequency domain over the time domain window function to the window function, j, ^ and " For the intermediate variable, c=l + , _{a = 2} X ), the parameter and the edge of the corresponding time domain window function

4 2 c flap width related; The ideal time domain window function includes a body portion, a side lobe portion, and a remaining portion, wherein the body portion has a value of 1, the width is, the side lobe portion value is less than 1, the width is "on the order of magnitude", and the remaining portion value is zero.

In conjunction with the second or third possible implementation of the second aspect, in a fourth possible implementation of the second aspect, the grouping subunit is further configured to:

And multiplying the shift signal by the frequency domain window function to obtain a product signal; respectively calculating, by using a discrete Fourier transform DFT, a first result and an index value when the index value of the product signal in the time domain is 0 Second result of the time; the calculated first result is

The second result is

In conjunction with the second or fourth possible implementation of the second aspect, in a fifth possible implementation of the second aspect, the exclusion subunit is further configured to:

Comparing the magnitude relationship between the first energy and the second energy: In the case of > /2, the index value of the shift signal in the time domain is excluded, and the set of the remaining values of the shift signal in the time domain is obtained as:

I ₀ = [ 1 ie {0,1,···«-1} and - /(mod n) e {0,1,· -·,η/ 4 + en)

I _X = [ 1 ie {0,1,···«-1} and w/2- (mod n) e {0, 1, ···,«/ 4 + cw)

J ₁

(mod/i) GI^.

With the second possible implementation of the second aspect, in a sixth possible implementation manner of the second aspect, if the intermediate frequency domain signal is excluded from the index value in the time domain, the remaining index values are configured. The set is A, and the intersection of the result of the set A and the previous iteration is a set S, and the determining subunit is further used for:

With reference to the second or sixth possible implementation manner of the second aspect, in the seventh possible implementation manner of the second aspect, the determining subunit determines to stop the iteration in the case that the following two conditions are met simultaneously : 1^1≤cn. The determining subunit calculates that the first parameter in the next iteration is the same as the first parameter in the previous iteration.

In conjunction with the first possible implementation of the second aspect, in an eighth possible implementation manner of the second aspect, the third unit is further configured to:

If the estimated index value is, the delay is nT _s , where 7: is the sampling period. Beneficial effect

In the positioning method of the embodiment of the present invention, in the process of each iteration, the intermediate frequency domain signals are grouped and the index value in the time domain is excluded until the iteration is terminated, and the delay of the original domain downsampling domain folding is determined to determine the delay. , reducing the complexity of positioning.

Further features and aspects of the present invention will become apparent from the Detailed Description of the Drawing. DRAWINGS

The accompanying drawings, which are incorporated in FIG

1 shows a flow chart of a positioning method in accordance with an embodiment of the present invention;

2 shows a flow chart of a positioning method according to another embodiment of the present invention;

3 is a block diagram showing the structure of a positioning device according to an embodiment of the invention;

4 is a block diagram showing the structure of a positioning device according to another embodiment of the present invention; detailed description

Various exemplary embodiments, features, and aspects of the invention are described in detail below with reference to the drawings. The same reference numerals in the drawings denote the same or similar elements. The various aspects of the embodiments are shown in the drawings, and the drawings are not necessarily drawn to scale unless otherwise indicated.

The word "exemplary" is used exclusively herein to mean "serving as an example, embodiment, or illustrative." Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous.

Further, in order to better illustrate the invention, numerous specific details are set forth in the Detailed Description. Those skilled in the art will appreciate that the invention may be practiced without some specific details. In other instances, well-known methods, means, components, and circuits are not described in detail to facilitate the invention.

1 shows a flow chart of a positioning method in accordance with an embodiment of the present invention. As shown in FIG. 1, the positioning method may mainly include:

Step 100: The receiving end receives a known sequence signal from each transmitting end.

Step 200: The receiving end performs a fast Fourier transform FFT on each of the known sequence signal and the received signal, where the received signal is a mixed signal formed by superposing each of the known sequence signals through channel fading. The FFT obtained by the known sequence signal is a first frequency domain signal, and the FFT obtained by the received signal is a second frequency domain signal.

Specifically, different transmitting ends (such as satellites, etc.) can respectively transmit different known sequence signals to the ground, and the known sequence signals need to have strong correlation, for example, can be a CDMA sequence. A mixed signal obtained by superimposing a plurality of different known sequence signals through channel fading is on the ground Received signal received by the receiving end. In a possible implementation manner, the receiving end may separately perform FFT transform on the received different known sequence signals and the received signals, and the known sequence signals may obtain the first frequency domain signal after FFT transform, and the received signals pass through The second frequency domain signal can be obtained after the FFT transform.

Step 300: Multiply the second frequency domain signal by each of the first frequency domain signals to obtain respective intermediate frequency domain signals.

Specifically, the first frequency domain signal obtained in step 200 and the second frequency domain signal are multiplied to obtain corresponding intermediate frequency domain signals. It should be noted that, according to the convolution theorem, the convolution of the two time domain signals is equal to the Fourier transform of the product of the corresponding two frequency domain signals, and the convolution operation is converted to Fourier through steps 200 and 300. The product of the transformation can effectively avoid the complexity of the convolution operation, thereby reducing the complexity of the positioning.

Step 400: Perform calculation on each intermediate frequency domain signal to obtain a delay corresponding to each intermediate frequency domain signal;

Step 500: Determine a location of the receiving end according to a delay corresponding to each intermediate frequency domain signal. Specifically, according to the respective intermediate frequency domain signals obtained above, the measurable maximum multipath delay can be used to perform corresponding operations. It is judged whether the iteration condition is satisfied. If it is satisfied, in the process of each iteration, the intermediate frequency domain signals are grouped and the index value in the time domain is excluded; if not, the iteration is terminated. Further, combined with the nature of the original domain downsampling transform domain folding, the delay corresponding to each intermediate frequency domain signal is obtained. By using the obtained delay, the product of the delay and the propagation speed of the electromagnetic wave can be used to obtain the distance from the transmitting end to the receiving end corresponding to different known sequence signals, and further, using different transmitting ends corresponding to different known sequence signals to the receiving end Distance, positioning of the receiving end can be achieved. In a possible implementation manner, the complexity of the positioning method mainly comes from step 400, that is, the operation of the intermediate frequency domain signal, wherein the complexity of grouping the intermediate frequency domain signals and excluding the index values in the time domain is O( l _0g ² « lo _g ), the complexity of frequency domain downsampling is O( H _0g , where

K

« is the length of the known sequence signal, which is the known maximum multipath delay. The complexity of the positioning method is O(m _ax l _0g ² _w lo _g ^, n _0g ). Compared with the existing positioning method, the positioning is reduced on the basis of considering the multipath channel shadow. The complexity.

In the positioning method of this embodiment, using the measurable maximum multipath delay, in the process of each iteration, the intermediate frequency domain signals are grouped and the index value in the time domain is excluded until the iteration is terminated, and combined with the original domain drop. The nature of the sampling transform domain folding, determining the delay, can be applied to multipath channels, reducing the complexity of positioning.

2 shows a flow chart of a positioning method in accordance with another embodiment of the present invention. The same steps in Fig. 2 as those in Fig. 1 have the same functions, and a detailed description of these steps will be omitted for the sake of brevity.

As shown in FIG. 2, the main difference between the positioning method shown in FIG. 2 and the positioning method shown in FIG. 1 is that, in the positioning method, the step 400 may specifically include:

Step 410: Perform an operation on the intermediate frequency domain signal, and obtain a first set, where the size of the first set is an order of magnitude of K, and the first set is composed of consecutive index values of the intermediate frequency domain signal in a time domain. K represents the maximum multipath delay of the channel.

For each of the intermediate frequency domain signals, the following methods may be used to calculate the delay corresponding to each intermediate frequency domain signal. Specifically, by performing an operation on the intermediate frequency domain signal, a first set of consecutive index values of the intermediate frequency domain signal in the time domain may be obtained, and the first set needs to satisfy an order of magnitude K, where K is known. The maximum multipath delay of the channel, the size of the first set representing the number of elements in the first set. Step 420: Perform frequency domain downsampling on the intermediate frequency domain signal according to a sampling interval O( _w / , and perform an inverse fast Fourier transform IFFT on the downsampled result, corresponding to obtaining a second set, where the second set is The result of the IFFT consists of index values sequentially taken in descending order of energy, where O is of the order of /, "for the total length of the known sequence signal, β is a known positive integer.

Specifically, after the frequency domain downsampling is performed on the intermediate frequency domain signal according to the sampling interval of the frequency domain downsampling, the result of the downsampling is IFFT transformed, and the index value corresponding to the time domain signal is calculated and transformed. The energy can be divided into two groups according to the energy index from the largest to the smallest. For example, β=5, the energy values corresponding to the energy in descending order are 3, 2, 4 5, 6, 7, 8, then 5 index values 3, 2, 4, 5, 6 can be taken in order from the largest to the smallest to form the second set. It can be a known positive integer set according to needs. The smaller the value, the lower the complexity of positioning, but the accuracy of positioning may decrease.

In a possible implementation manner, if the first set is S and the number of elements included is (κ), gp |s| = O( ), the sampling interval may be determined as “/M, The intermediate frequency domain signal is subjected to frequency domain downsampling, where M = 2 ^m , 2 ^m - ¹ < |S| ≤ 2 ^m , and m is a positive integer.

Step 430: Perform an intersection operation on the first set and the second set corresponding to the intermediate frequency domain signal, and determine a delay corresponding to the intermediate frequency domain signal according to the result of the intersection operation.

After performing the above steps 410 to 430 for each intermediate frequency domain signal, the delay corresponding to each intermediate frequency domain signal may be separately determined. By obtaining a plurality of delays, the distance from the transmitting end to the receiving end of the known sequence signal corresponding to each intermediate frequency domain signal can be obtained by using the product of the delay and the electromagnetic wave propagation speed, and further, using a plurality of different known sequence signals correspondingly Different launch The distance from the end to the receiving end can be used to locate the receiving end.

Further, in the case that the iterative condition is satisfied, the above intermediate frequency domain signals may be transformed, grouped, and the index values in the time domain may be excluded by the following methods, respectively. Step 410 specifically includes:

Step 411: Perform transform domain expansion on the intermediate frequency domain signal according to the first parameter, and obtain an extended signal corresponding to the transform domain, where the transform domain is a time domain.

Specifically, the formula (Ρ _σ Α = can be used to calculate the extended signal corresponding to the intermediate frequency domain signal) ^ where = (Ρ _σ Α = is the extended signal corresponding to the intermediate frequency domain signal; Ρ _σ represents a pair of middle The frequency domain signal performs transform domain expansion transformation; the corresponding transform domain real-time domain signal is d=; σ is the first parameter, σ is a positive odd number not 1; k = 0~nl.

Step 412: Perform a transform domain shift on the extended signal according to the second parameter, and obtain a shift signal correspondingly.

Specifically, the shift signal corresponding to the expanded signal can be calculated by using the formula (Ρ^) _λ =>^^; wherein Λ=(3⁄4 =>^^ is the shift signal corresponding to the expanded signal ;; Represents a transform that transforms the transform signal by transform domain; _w = _e - ² = -1 _;信号 corresponds to the transform domain in the immediate domain signal is 3⁄4^=; b is the second parameter; k = 0~nl .

Step 413: Divide the shift signals into two groups according to a frequency domain window function configured offline, and calculate energy of the two groups separately;

Step 414: Exclude an index value of the intermediate frequency domain signal in the time domain according to the size relationship of the two packet energies.

Specifically, the window function can process the signal, and the shift signals obtained by the above can be divided into two groups by discretely constructing a suitable frequency domain window function, and the two groups respectively have their own energy. Comparing the size relationship of the two packet energies, the index value of the shifted signal in the time domain can be excluded, and the index value of the intermediate frequency domain signal in the time domain is excluded, and the corresponding set of remaining index values is obtained for subsequent use. Determine the delay and achieve positioning.

In a possible implementation manner, the frequency domain window function constructed offline may be: ϊ = 0Χ· · ·, η -1

Wherein, the frequency domain window function is a preset parameter for indicating an absolute error between the time domain window function corresponding to the frequency domain window function and the ideal time domain window function, j, ^ and "for the middle

C = , the parameter c and the corresponding time domain window function

Degree related. Wherein, the ideal time domain window function comprises a body portion, a side lobe portion and a remaining portion, wherein the main body portion has a value of 1, the width is, the side lobe portion value is less than 1, the width is OW is "the order of magnitude, and the remaining portion value is 0. In this case, the shift signal is divided into two groups according to the frequency domain window function, and calculating the energy of the two groups separately may include the following steps:

The shift signal is multiplied by the frequency domain window function to obtain a product signal. For example, if the frequency domain window function is G and the shift signal is /, then the product signal is G x /. Calculating a second result of the result and the index value when the index value of the product signal is 0 in the time domain by using a discrete Fourier transform DFT; the first result calculated is:

Z ₀ = G xf _Q = 2l ⁺ Σ

The second result is

Wherein, the first result is a value when the index value of the product signal in the time domain is 0; 2 is the second result, that is, a value when the index value of the product signal is in the time domain; The frequency domain window function; 0 is a time domain window function corresponding to the frequency domain window function; / is the shift signal; is a time domain signal corresponding to the shift signal; and is a time corresponding to the product signal Domain signal. The first energy is | | ² and the second energy is | £ _/2 ² .

In a possible implementation manner, comparing the relationship between the first energy and the second energy, the index value of the intermediate frequency domain signal in the time domain may be excluded, thereby obtaining a set of remaining index values.

Specifically, if the first energy is not less than the second energy, excluding an index value of the shift signal in a time domain, and obtaining an index value of the remaining value of the shift signal in a time domain. The collection is:

Ι ₀ = [ 1 e {0,1,···«-1} and - /(mod ne [0,1,· -·,η/ 4 + cn

In the case that the first energy is not greater than the second energy, the index value of the shift signal in the time domain is excluded, and the set of index values remaining in the time domain of the shift signal is obtained as follows:

I _x = i I e {0,1,···«-1} and n/2 -i (mod n) e {θ,1,···,η/ 4 + cn)

U {3w/4 - cn, 3n/4 -cn + l,---,n}} The corresponding set of index values of the intermediate frequency domain signal in the time domain is:

Further, after step 414, the method may further include:

Step 415: Calculate the first parameter and the second parameter in the next iteration, and determine whether the next iteration condition is met.

Specifically, during each iteration, the first parameter for transform domain expansion and the second parameter for transform domain shift are varied, requiring computation before each iteration. The calculation method is as follows: The condition that the first parameter σ needs to satisfy is: σ is a positive odd number that is not 1, and _σ |^| ≤ , where W is the size of the set S, if each iteration is excluded, After the intermediate frequency domain signal is after the index value in the time domain, and the remaining index values form a set of Α, the intersection of the set Α and the result of the previous iteration is the set S.

The condition that the second parameter b needs to satisfy is: -b = where _m is the midpoint of the index value in the set S.

In one possible way, before each iteration, it is also necessary to judge whether the iterative condition is satisfied, wherein the iterative condition cannot be satisfied if both of the following conditions are satisfied, and the iteration can be terminated: |^|≤ _^; the same as in the previous iteration of the next iteration of the first parameter calculated in the first parameter.

In a possible implementation, determining the delay corresponding to the intermediate frequency domain signal according to the result of the intersection operation may further include: determining an estimated index according to the magnitude relationship of the energy corresponding to the index value in the result of the intersection operation a value; if the estimated index value is, the delay is nT _s , where is a sampling period.

Specifically, in a normal case, the estimated index value may be determined according to the magnitude relationship of the energy corresponding to the index value in the intersection operation result. For example, if the set of index values obtained by the intersection operation is { ² , 3, ⁴ , 5, 6, ⁷ , 8}, the index can be calculated according to the order of the index values from small to large. The energy corresponding to the value 2 is 0.5, the energy corresponding to the index value 3 is 0.6, the energy corresponding to the index value 4 is 0.5, the energy corresponding to the index value 5 is 11, the energy corresponding to the index value 6 is 10, and the energy corresponding to the index value 7 9, the energy corresponding to the index value 8 is 0.6, and the energy corresponding to the index values 5, 6, and 7 is larger, and the average value is 10. The index value 5 is the index value of the first energy greater than the average value. , you can determine the index value 5 is the estimated index value. If the estimated index value is as 7), what is the sampling period? : (eg 100ms), the delay can be determined as = V00ms.

In a possible implementation, the distance between the transmitting end and the receiving end can be obtained according to the product of the delay and the electromagnetic wave propagation speed. After measuring the distance from the multiple transmitting ends to the receiving end, the spherical surface can be made with the radius of each transmitting end to the receiving end as the center, and the intersection between the multiple spherical surfaces is the position of the receiving end. Positioning on the receiving end.

It should be noted that the frequency domain window function of the offline configuration can be in many forms. In this embodiment, only a achievable manner is provided, but it is not limited thereto. Specifically, for the positioning method provided in this embodiment, in the case where the frequency domain window function is changed, the corresponding grouping, energy, and the set obtained by excluding the value of the window in the time domain will change accordingly.

FIG. 3 is a block diagram showing the structure of a positioning apparatus according to an embodiment of the present invention. As shown in FIG. 3, the positioning device 300 can mainly include:

The receiving module 301 is configured to receive a known sequence signal from each of the transmitting ends, respectively;

a transform module 302, connected to the receiving module 301, for using each of the known sequence signals And performing a fast Fourier transform FFT separately from the received signal, wherein the received signal is a mixed signal obtained by superposing each of the known sequence signals by channel fading, wherein the known sequence signal is obtained by FFT. The frequency domain signal is obtained by the FFT after the received signal is a second frequency domain signal.

Specifically, different transmitting ends (e.g., satellites, etc.) can respectively transmit different known sequence signals to the ground, and the known sequence signals need to have strong correlation, for example, can be a CDMA sequence. The mixed signal obtained by superimposing a plurality of different known sequence signals through channel fading is the received signal received by the receiving module 301. In a possible implementation manner, the transform module 302 may separately perform FFT transform on the received different known sequence signals and the received signals, and obtain the first frequency domain signal by using the FFT transform of the known sequence signal, and receive the signal. After the FFT transform, the second frequency domain signal can be obtained.

The transform module 302 is further configured to multiply the second frequency domain signal by each of the first frequency domain signals to obtain respective intermediate frequency domain signals.

Specifically, multiplying the first frequency domain signal obtained by the transform module 302 and the second frequency domain signal to obtain corresponding intermediate frequency domain signals. It should be noted that, according to the convolution theorem, the convolution of the two time domain signals is equal to the Fourier transform of the product of the corresponding two frequency domain signals, and the convolution operation is converted into Fourier by the processing of the transform module 302. The product of the transformation can effectively avoid the complexity of the convolution operation, thereby reducing the complexity of the positioning.

The operation module 303 is connected to the conversion module 302, and is configured to perform operations on each intermediate frequency domain signal to obtain a delay corresponding to each intermediate frequency domain signal;

The positioning module 304 is connected to the computing module 303, and is configured to determine a location of the receiving end according to a delay corresponding to each intermediate frequency domain signal.

Specifically, according to the intermediate frequency domain signals obtained by the foregoing transform module 302, The calculation module 303 performs the corresponding operation using the measurable maximum multipath delay. The operation module 303 first determines whether the iteration condition is satisfied. If it is satisfied, in the process of each iteration, the intermediate frequency domain signals are grouped and the index value in the time domain is excluded; if not, the iteration is terminated. Further, combined with the nature of the original domain downsampling transform domain folding, the delay corresponding to each intermediate frequency domain signal is obtained. The positioning module 304 can obtain the distance from the transmitting end to the receiving end corresponding to different known sequence signals by using the product of the delay and the electromagnetic wave propagation speed, and further, using different transmitting ends corresponding to a plurality of different known sequence signals. The distance to the receiving end can be used to locate the receiving end.

In a possible implementation manner, in the process of performing positioning, the positioning device 300 mainly comes from the operation module 303, that is, the intermediate frequency domain signal is calculated, wherein the intermediate frequency domain signals are grouped and the time domain is excluded. The complexity of the index value on the O is 0 ( l _0g ² _W l _0g ), frequency domain downsampling

K

The complexity is O^log C where w is the length of the known sequence signal and is the known maximum multipath delay. Then, the positioning device 300 performs the positioning process, and the complexity is

^{_{O (max (log 2 W log-}} , log}), compared with the conventional positioning means, in consideration of the influence of multi-path channel k) based on the realization of the complexity of the targeted reduction.

In the positioning device of this embodiment, the computing module uses the measurable maximum multipath delay, and in each iterative process, the intermediate frequency domain signals are grouped and the index values in the time domain are excluded until the iteration is terminated, and the original is combined. The nature of the domain downsampling transform domain folding, determining the delay, can be applied to multipath channels, reducing the complexity of positioning.

4 shows a flow chart of a positioning device in accordance with another embodiment of the present invention. The same components in Fig. 4 as those in Fig. 3 have the same functions, and a detailed description of these components will be omitted for the sake of brevity.

As shown in FIG. 4, the main difference between the positioning device 400 shown in FIG. 4 and the positioning device 300 shown in FIG. 3 is that, in the positioning device 400, the computing module 303 may specifically include: The first unit 401 is configured to perform operations on the intermediate frequency domain signal, and correspondingly obtain a first set, where the size of the first set is an order of magnitude of K, and the first set is continuous by the intermediate frequency domain signal in a time domain. The index value is composed, and K represents the maximum multipath delay of the channel.

For each intermediate frequency domain signal obtained by the above transformation module 302, the operation module 303 can perform operations by using the following methods to obtain delays corresponding to the respective intermediate frequency domain signals. Specifically, the first frequency unit is used to calculate the intermediate frequency domain signal, and the first set of consecutive index values of the intermediate frequency domain signal in the time domain is obtained, and the first set needs to satisfy the magnitude of the magnitude K, where K For the maximum multipath delay of the known channel, the size of the first set represents the number of elements in the first set.

The second unit 402 is connected to the first unit 401, configured to perform frequency domain downsampling on the intermediate frequency domain signal according to a sampling interval O(/, and perform an inverse fast Fourier transform IFFT on the downsampled result, Correspondingly, a second set is obtained, wherein the second set is composed of index values sequentially extracted from the result of the IFFT according to the energy from the largest to the smallest, where O is of the order of magnitude, and n is the total of the known sequence signals. Length, which is a known positive integer.

Specifically, the second unit 402 may perform frequency domain down-sampling on the intermediate frequency domain signal according to the sampling interval of the frequency domain downsampling, and then perform IFFT transformation on the downsampled result, and calculate and transform to obtain a corresponding time domain signal. The energy corresponding to the index value may be a second set according to the index values sequentially taken from the largest to the smallest energy. For example, β=5, the energy value corresponding to each energy in order from the largest to the smallest is 3 2, 4, 5, 6, 7, 8, then 5 index values 3, 2, 4, 5, 6 can be taken in order from the largest to the smallest to form the second set. ^ Can be set as needed A known positive integer, the smaller the value, the lower the complexity of positioning, but the accuracy of positioning may be reduced. In a possible implementation manner, if the first set is s, the number of elements included is

0{K),

Then, the second unit 402 may determine the sampling interval as i/M, and perform frequency domain downsampling on the intermediate frequency domain signal, where M=l ^m , 2 ^m - ¹ <|S|<2TM, m is positive Integer.

The third unit 403 is connected to the second unit 402, and is configured to perform an intersection operation on the first set and the second set corresponding to the intermediate frequency domain signal, and determine, according to a result of the intersection operation, the intermediate frequency domain signal corresponding Delay.

After the operation module 303 performs the above operations on the respective intermediate frequency domain signals, the delay corresponding to each intermediate frequency domain signal can be determined separately. By obtaining a plurality of delays, the positioning module 304 can obtain the distance from the transmitting end to the receiving end of the known sequence signal corresponding to each intermediate frequency domain signal by using the product of the delay and the electromagnetic wave propagation speed. Further, using a plurality of different known The distance from the different transmitting end to the receiving end corresponding to the sequence signal can realize the positioning of the receiving end.

Further, the first unit 401 further includes an expansion subunit 4011, a shift subunit 4012, a grouping subunit 4013, an excluding subunit 4014, and a judging subunit 4015. When the iterative condition is satisfied,

The expansion subunit 4011 is configured to perform a transform domain expansion on the intermediate frequency domain signal according to the first parameter, and correspondingly obtain an extended signal, where the transform domain is a time domain.

Specifically, the expansion subunit 4011 can calculate an expansion signal corresponding to the intermediate frequency domain signal by using a formula (Ρ _σ Α = , where Λ = (Ρ _σ Α = an expansion signal corresponding to the intermediate frequency domain signal; Transforming the transform domain expansion of the intermediate frequency domain signal; the signal in the corresponding transform domain immediate domain is ^^二^; σ is the first parameter, σ is a positive odd number not 1; k=0~nl.

a shift subunit 4012, coupled to the expansion subunit 4011, for The expansion signal is subjected to a transform domain shift, and a shift signal is obtained correspondingly.

Specifically, the shift subunit 4012 can calculate a shift signal 对应 corresponding to the spread signal by using a formula (Ρ^ Η^; wherein Λ=(Ρ)3⁄4 = Λ is the expansion signal) Signal; represents a transform that transforms the transform signal by transform domain; w = _e - ² = -1; 信号 the signal in the corresponding transform domain immediate domain is = ; b is the second parameter; k = 0 ~ _n - l.

The grouping subunit 4013 is connected to the shifting subunit 4012, and is configured to divide the shift signals into two groups according to a frequency domain window function configured offline, and calculate energy of the two groups separately;

The exclusion subunit 4014 is connected to the grouping subunit 4013, and is configured to exclude an index value of the intermediate frequency domain signal in the time domain according to the size relationship of the two packet energies.

Specifically, the window function can process the signal, and the grouping subunit 4013 can divide the obtained shift signal into two groups by discretely constructing a suitable frequency domain window function, and the two groups respectively have their own energy, by comparing two The size relationship of the packet energy, the exclusion sub-unit 4014 can exclude the index value of the shift signal in the time domain, and thereby exclude the index value of the intermediate frequency domain signal in the time domain, and obtain a set of corresponding residual index values for use in Subsequent determination of the delay and implementation of the positioning.

In a possible implementation manner, the frequency domain window function constructed offline may be:

Wherein, the frequency domain window function is a preset parameter for indicating an absolute error between the time domain window function corresponding to the frequency domain window function and the ideal time domain window function, j, ^ and "for the middle Variable, c=l+^, the edge of the corresponding time domain window function

4 2 _{a = 2} X c ), the parameter is related to the width of the flap. Wherein, the ideal time domain window function comprises a body portion, a side lobe portion and a remaining portion, wherein the main body portion has a value of 1, the width is ^ the side lobe portion value is less than 1, and the width is 0^) The order of magnitude, the remaining part is 0. In this case, the grouping subunit 4013 is further configured to: separately perform a product operation on the shift signal and the frequency domain window function to obtain a product signal. For example, if the frequency domain window function is G and the shift signal is /, the product signal is Gx /.

Calculating a second result of the result and the index value when the index value of the product signal is 0 in the time domain by using a discrete Fourier transform DFT; the first result calculated is:

∑ GJ— _n + ∑ Gj_ _{n The} second result is

In a possible implementation manner, by comparing the magnitude relationship between the first energy and the second energy, the exclusion subunit 4014 can exclude the index value of the intermediate frequency domain signal in the time domain, thereby obtaining the remaining index. A collection of values.

Specifically, if the first energy is not less than the second energy, excluding an index value of the shift signal in a time domain, and obtaining an index value of the remaining value of the shift signal in a time domain. The collection is: I ₀ = [ 1 e |0,l,---wl} and - /(mod ne [0,1,· -·,η/ 4 + cn

I _x = i I e {0,1,···«-1} and n/2-i(modn) e {θ,1,···,η/ 4 + cn)

U {3w/4 - cn, 3n/4 -cn + l,---,n}}

Further, the first unit 401 may further include:

The determining subunit 4015 is connected to the exclusion subunit 4014 for calculating the first parameter and the second parameter in the next iteration, and determining whether the next iteration condition is satisfied.

Specifically, during each iteration, the first parameter for transform domain expansion and the second parameter for transform domain shift are varied, requiring computation before each iteration. The judgment method used by the judgment subunit 4015 is as follows:

The condition that the first parameter σ needs to satisfy is: σ is a positive odd number that is not 1, and _σ |^| ≤ , where W is the size of the set S, and if the intermediate frequency domain signal is excluded during each iteration After the index value in the time domain, the set of remaining index values is Α, then the intersection of the result of the set Α and the previous iteration is the set S.

In one possible way, before each iteration, the judgment subunit 4015 needs to judge Whether the iterative condition is satisfied, wherein the iterative condition cannot be satisfied while satisfying the following two conditions, and the determining subunit 4015 determines that the iteration can be terminated: |s| ≤ _; calculating the first one in the next iteration The parameters are the same as the first parameter in the previous iteration.

In a possible implementation manner, the third unit 403 is further configured to: determine an estimated index value according to a magnitude relationship of energy corresponding to the index value in a result of the intersection operation; and if the estimated index value is Then the delay is nT _s , where 7: is the sampling period.

Specifically, in a normal case, the third unit 403 may determine the estimated index value according to the magnitude relationship of the energy corresponding to the index value in the intersection operation result. For example, if the set of index values obtained by the third unit 403 by the intersection operation is { ² , 3, ⁴ , 5, 6, ⁷ , 8}, the index value can be calculated according to the order of the index values from small to large. The energy corresponding to 2 is 0.5, the energy corresponding to index value 3 is 0.6, the energy corresponding to index value 4 is 0.5, the energy corresponding to index value 5 is 11, the energy corresponding to index value 6 is 10, and the energy corresponding to index value 7 is 9, the index value 8 corresponds to an energy of 0.6, compared to the index value of 5, 6, 7 corresponding to a larger energy, the average value of 10, the index value 5 is the first energy is greater than the above average value of the index value, The third unit 403 can determine that the index value 5 is an estimated index value. If the estimated index value is as 7) and the sampling period is (eg, 100 ms), the delay may be determined as nT _s = 700 ms.

It should be noted that the frequency domain window function of the offline configuration can be in many forms. In this embodiment, only a achievable manner is provided, but it is not limited thereto. Specifically, for the positioning apparatus provided in this embodiment, when the frequency domain window function is changed, the results obtained by each component operation will be The corresponding changes have taken place.

Fig. 5 is a block diagram showing the construction of a positioning device in accordance with another embodiment of the present invention. The positioning device 1100 may be a host server having a computing capability, a personal computer PC, or a portable portable computer or terminal. The specific embodiment of the present invention does not limit the specific implementation of the computing node.

The locating device 1100 includes a processor 110, a communications interface 1120, a memory 130, and a bus 1140. Among them, the processor 1110, the communication interface 1120, and the memory 1130 complete communication with each other through the bus 1140.

Communication interface 1120 is for communicating with network devices, such as virtual machine management centers, shared storage, and the like.

The processor 1110 is for executing a program. The processor 1110 may be a central processing unit CPU, or an Application Specific Integrated Circuit (ASIC), or one or more integrated circuits configured to implement embodiments of the present invention.

The memory 1130 is used to store files. The memory 1130 may include a high speed RAM memory, and may also include a non-volatile memory such as at least one disk memory. Memory 1130 can also be a memory array. The memory 1130 may also be partitioned, and the blocks may be combined into a virtual volume according to certain rules.

In a possible implementation manner, the foregoing program may be a program generation including a computer operation instruction. code. This program can be used to:

Receiving a known sequence signal from each transmitting end;

Performing a fast Fourier transform FFT on each of the known sequence signals and the received signals, wherein the received signals are mixed signals obtained by superposing each of the known sequence signals by channel fading, wherein the known sequence The signal obtained after the FFT is the first frequency domain signal, and the FFT after the received signal is the second frequency domain signal;

In a possible implementation, the operation is performed on each intermediate frequency domain signal to obtain a delay corresponding to each intermediate frequency domain signal, including:

Performing an operation on the intermediate frequency domain signal, corresponding to obtaining a first set, the size of the first set is

An order of magnitude of K, the first set consisting of consecutive index values of the intermediate frequency domain signal in the time domain, and K represents a maximum multipath delay of the channel;

Performing frequency domain downsampling on the intermediate frequency domain signal according to a sampling interval O(, and performing an inverse fast Fourier transform IFFT on the downsampled result, corresponding to obtaining a second set, the second set being the result of the IFFT And consisting of index values sequentially taken in order of increasing energy, wherein O is of the order of magnitude; "is the total length of the known sequence signal, which is a known positive integer;

Performing an intersection operation on the first set and the second set corresponding to the intermediate frequency domain signal, and determining a delay corresponding to the intermediate frequency domain signal according to the result of the intersection operation. In a possible implementation manner, the performing the operation on the intermediate frequency domain signal, corresponding to obtaining the first set, and performing the iterative condition, performing the following steps:

In a possible implementation manner, before the shifting signals are divided into two groups according to a frequency domain window function configured offline, the method includes:

Function

Wherein, the frequency domain window function is a preset parameter for indicating an absolute error between the time domain window function corresponding to the frequency domain window function and the ideal time domain window function, j, ^ and "for the middle Variable, c=l + , _{a = 2} X ), the parameter and the edge of the corresponding time domain window function

4 2 c flap width related;

The ideal time domain window function includes a body portion, a side lobe portion and a remaining portion, wherein the main body portion has a value of 1, the width is ^, the side lobe portion value is less than 1, and the width is OW is "the order of magnitude, remaining ^{: the} score is 0 _t

In a possible implementation manner, calculating energy of two groups separately includes: multiplying the shift signal by the frequency domain window function to obtain a product signal; respectively using a discrete Fourier transform DFT calculation The first result when the index value of the product signal is 0 in the time domain and the second result when the index value is; the first result calculated is:

∑ GJ— _n + ∑ Gj_ _{n The} second result is

Wherein, the second is the second result, that is, the value of the product signal when the index value is in the time domain; G is the frequency domain window function; 0 is the time domain corresponding to the frequency domain window function a window function; / is the shift signal; a time domain signal corresponding to the shift signal; ^ is a time domain signal corresponding to the product signal; the first energy is | £. | ² , the second energy is |£„ _/2 ² .

In a possible implementation, the index value of the intermediate frequency domain signal in the time domain is excluded according to the relationship between the first energy and the second energy, including:

Comparing the magnitude relationship between the first energy and the second energy:

In the case of the exclusion of the index value of the shift signal in the time domain, the set of the remaining values of the shift signal in the time domain is obtained as:

/. = [ 1 / G |0,1, · · ·/ι -ΐ} and - /(mod n) G {0,1,- - -, /I/ 4 + C/I)

I _x = i I e {0,1,···«-1} and n/2-i(modn) e {θ,1,···,η/ 4 + cn)

In a possible implementation manner, if the intermediate frequency domain signal is excluded from the index value in the time domain and the remaining index values form a set A, the intersection of the result of the set A and the previous iteration is The set S, the calculating the first parameter and the second parameter in the next iteration, and the condition that the first parameter needs to be satisfied is: σ is a positive odd number that is not 1, and σ ≤ , where Μ For the size of the set S;

In a possible implementation manner, when the following two conditions are met simultaneously, the stacking is stopped.

Calculating the first parameter in the next iteration and the first in the previous iteration

In a possible implementation, the first set and the second set corresponding to the intermediate frequency domain signal are subjected to an intersection operation, and the time corresponding to the intermediate frequency domain signal is determined according to the result of the intersection operation. Delay, including:

If the estimated index value is, the delay is nT _s , where 7: is the sampling period. Those of ordinary skill in the art will appreciate that the various exemplary units and algorithm steps in the embodiments described herein can be implemented in electronic hardware or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the solution. A person skilled in the art can select different methods for implementing the described functions for a particular application, but such implementation should not be considered to be beyond the scope of the present invention.

If the function is implemented in the form of computer software and sold or used as a stand-alone product, it may be considered to some extent that all or part of the technical solution of the present invention (for example, a part contributing to the prior art) is It is embodied in the form of computer software products. The computer software product is typically stored in a computer readable non-volatile storage medium, including instructions for causing a computer device (which may be a personal computer, server, or network device, etc.) to perform all of the methods of various embodiments of the present invention. Or part of the steps. The foregoing storage medium includes various media that can store program codes, such as a USB flash drive, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk, or an optical disk.

The above is only the specific embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily think of changes or substitutions within the technical scope of the present invention. It should be covered by the scope of the present invention. Therefore, the scope of the invention should be determined by the scope of the appended claims.

Claims

claims

1. A positioning method, characterized by including:

The receiving end receives known sequence signals from each transmitting end;

The receiving end performs fast Fourier transform FFT on each of the known sequence signals and the received signal respectively. The received signal is a mixed signal formed by superimposing each of the known sequence signals through channel fading, where, The first frequency domain signal is obtained after FFT of the known sequence signal, and the second frequency domain signal is obtained after FFT of the received signal;

Multiply the second frequency domain signal with each of the first frequency domain signals to obtain each intermediate frequency domain signal;

Calculate each intermediate frequency domain signal to obtain the time delay corresponding to each intermediate frequency domain signal; determine the position of the receiving end according to the time delay corresponding to each intermediate frequency domain signal.

2. The positioning method according to claim 1, characterized in that the operation on each intermediate frequency domain signal is performed to obtain the time delay corresponding to each intermediate frequency domain signal, including:

The intermediate frequency domain signal is operated to obtain a first set. The size of the first set is of the order of K. The first set is composed of continuous index values of the intermediate frequency domain signal in the time domain. K represents the channel. The maximum multipath delay;

According to the sampling interval O ( , perform frequency domain downsampling on the intermediate frequency domain signal, and perform inverse fast Fourier transform IFFT on the downsampling result, correspondingly obtaining a second set. The second set is formed by the result of the IFFT It consists of index values taken out in order from large to small energy, where O is the order of magnitude of; " is the total length of the known sequence signal, and is a known positive integer;

An intersection operation is performed on the first set and the second set corresponding to the intermediate frequency domain signals, and the time delay corresponding to the intermediate frequency domain signals is determined according to the result of the intersection operation.

3. The positioning method according to claim 2, characterized in that the operation on the intermediate frequency domain signal corresponds to a first set, and when the iteration conditions are met, the following steps are performed: According to the first parameter, The intermediate frequency domain signal undergoes transform domain expansion to obtain an expanded signal, where the transform domain is the time domain;

According to the second parameter, perform a transform domain shift on the expanded signal to obtain a corresponding shifted signal; divide the shifted signal into two groups according to the frequency domain window function constructed offline, and calculate the energy of the two groups respectively;

According to the relationship between the energy of the two packets, the index value of the intermediate frequency domain signal in the time domain is eliminated;

Calculate the first parameter and the second parameter in the next iteration, and determine whether the next iteration condition is met.

4. The positioning method according to claim 3, characterized in that, before dividing the shift signal into two groups according to the frequency domain window function constructed offline, it includes:

function;

Among them, is the frequency domain window function, is a preset parameter, is used to represent the absolute error between the time domain window function corresponding to the frequency domain window function and the ideal time domain window function, j, ^ and 〈 are the middle Variables, c =l +, _{a = 2} X), parameters and the edges of the corresponding time domain window function

4 2 c is related to the width of the flap;

The ideal time domain window function includes a main part, a side lobe part and a remaining part, where the main part value is 1, the width is ^, the side lobe part value is less than 1, the width is OW, which is the order of magnitude of , and the remaining part is ^: The score is 0 _t

. The positioning method according to claim 3 or 4, characterized in that calculating the energy of two V groups respectively includes:

Perform a product operation on the shift signal and the frequency domain window function to obtain a product signal; use discrete Fourier transform DFT to calculate the first result and index value of the product signal when the index value in the time domain is 0. The second result is; the first result calculated is:

∑ GJ— _n + ∑ Gj_ _nThe second result is

z = Gx f _n/2 = ∑ GJ _r + where, is the second result, that is, the value when the index value of the product signal in the time domain is; G is the frequency domain window function; 0 is the time domain window function corresponding to the frequency domain window function; / is the shift signal; is the time domain signal corresponding to the shift signal; ^ is the time domain signal corresponding to the product signal; One energy is ^. | ² , the second energy is |£„ _/2 ² .

6. The positioning method according to claim 3 or 5, characterized in that, according to the magnitude relationship between the first energy and the second energy, excluding the index value of the intermediate frequency domain signal in the time domain includes: comparing The magnitude relationship between the first energy and the second energy;

In the case of , excluding the index value of the shift signal in the time domain, the set of the remaining index I values of the shift signal in the time domain is obtained: I ₀ = [ 1 e {0,l,---wl} and - /(mod n) e {0,1,· -·,η/ 4 + en)

The corresponding set of remaining index values of the intermediate frequency domain signal in the time domain is:

In ^. When | ² ≤ | ₂ | ² , excluding the index value of the shift signal in the time domain, the set of remaining index I values of the shift signal in the time domain is:

I _x = i I e {0,1,···«-1} and n/2-i(modn) e {θ,1,···,η/ 4 + cn)

The set of remaining index values of the intermediate frequency domain signal in the time domain corresponding to U {3w/4 - cn, 3n/4 -cn + l,---,n}} is:

7. The positioning method according to claim 3, characterized in that, after excluding the index value of the intermediate frequency domain signal in the time domain, the set of remaining index values is A, then the set A is the same as the previous set. The intersection of the results of one iteration is the set S. The calculation of the first parameter and the second parameter in the next iteration includes:

The conditions that the first parameter needs to meet are: σ is a positive odd number that is not 1, and σ ≤ , where M is the size of the set S;

The conditions that the second parameter needs to meet are: - , where _m is the midpoint of the index value in the set S.

8. The positioning method according to claim 3 or 7, characterized in that, when the following two conditions are met at the same time, the iteration is stopped:

1^1 <cn;

The first parameter in the next iteration is calculated to be the same as the first parameter in the previous iteration.

9. The positioning method according to claim 2, characterized in that, an intersection operation is performed on the first set and the second set corresponding to the intermediate frequency domain signals, and the corresponding intermediate frequency domain signal is determined according to the result of the intersection operation. The delay includes:

Determine the estimated index value according to the energy magnitude relationship corresponding to the index value in the intersection operation result;

If the estimated index value is , then the time delay is nT _s , where _rs is the sampling period.

10. A positioning device, characterized in that it includes:

A receiving module, used to receive known sequence signals from each transmitter;

A transformation module, connected to the receiving module, is used to perform fast Fourier transform FFT on each of the known sequence signals and the received signal. The received signal is superposed by each of the known sequence signals through channel fading. The resulting mixed signal is a first frequency domain signal obtained by FFT of the known sequence signal, and a second frequency domain signal obtained by FFT of the received signal;

The transformation module is also used to multiply the second frequency domain signal with each of the first frequency domain signals to obtain each intermediate frequency domain signal;

An operation module, connected to the transformation module, is used to perform operations on each intermediate frequency domain signal to obtain the time delay corresponding to each intermediate frequency domain signal;

A positioning module is connected to the computing module and used to determine the position of the receiving end based on the time delay corresponding to each intermediate frequency domain signal.

11. The positioning device according to claim 10, characterized in that the operation module includes: a first unit, used to operate on the intermediate frequency domain signal, corresponding to obtain a first set, the size of the first set is The order of magnitude of K, the first set consists of the intermediate frequency domain signal in the time domain The second unit is connected to the first unit and is used to perform frequency domain downsampling on the intermediate frequency domain signal according to the sampling interval 0 ("/^), and perform inverse fast Fourier transform IFFT on the downsampling result. , corresponding to the second set, which is composed of index values taken out from the IFFT result in order from large to small energy, where O is the order of /, " is the known sequence signal The total length of is a known positive integer;

The third unit, connected to the second unit, is used to perform an intersection operation on the first set and the second set corresponding to the intermediate frequency domain signals, and determine the time corresponding to the intermediate frequency domain signals according to the result of the intersection operation. extension.

12. The positioning device according to claim 11, wherein the first unit further includes an expansion subunit, a shift subunit, a grouping subunit, an exclusion subunit, and a judgment subunit. When the iteration conditions are met, Down,

The expansion subunit is used to perform transform domain expansion on the intermediate frequency domain signal according to the first parameter, and correspondingly obtain an expanded signal, wherein the transform domain is the time domain;

The shift subunit is connected to the expansion subunit, and is used to perform transform domain shift on the expansion signal according to the second parameter, and correspondingly obtain a shift signal;

The grouping subunit is connected to the shift subunit, and is used to divide the shift signal into two groups according to the frequency domain window function constructed offline, and calculate the energy of the two groups respectively;

The elimination subunit is connected to the grouping subunit and is used to exclude the index value of the intermediate frequency domain signal in the time domain according to the magnitude relationship of the two grouping energies;

The judgment subunit is connected to the exclusion subunit, and is used to calculate the first parameter and the second parameter in the next iteration, and judge whether the next iteration condition is met.

13. The positioning device according to claim 12, wherein the grouping subunit further Used for:

Among them, G,. is the frequency domain window function, is a preset parameter, and is used to represent the absolute error between the time domain window function corresponding to the frequency domain window function and the ideal time domain window function, j, ^ and "For, α = 2 X -)

, parameter <the edge of the corresponding time domain window function

related to flap width;

The ideal time domain window function includes a main part, a side lobe part and a remaining part, where the main body score is 1, the width is , the side lobe part value is less than 1, the width is on the order of ", that is, the remaining part

^: The score is 0 _t

14. The positioning device according to claim 12 or 13, characterized in that the grouping subunit is also used for:

Perform a product operation on the shift signal and the frequency domain window function to obtain a product signal; respectively use discrete Fourier transform DFT to calculate n when the index value of the product signal in the time domain is 0

The first result of and the second result when the index value is; The calculated first result is

The second result is z

Among them, is the mentioned

Π

/ ₂ is the second result, that is, the index value of the product signal in the time domain is the value; G is the frequency domain window function; 0 is the time domain window function corresponding to the frequency domain window function; / is The shift signal; is the time domain signal corresponding to the shift signal; ^ is the time domain signal corresponding to the product signal; and the first energy is ^. | ² , the second energy is |£„ _/2 ² .

15. The positioning device according to claim 12 or 14, characterized in that the exclusion subunit is also used to:

Compare the magnitude relationship between the first energy and the second energy;

In the case of > /2, excluding the index value of the shift signal in the time domain, the set of the remaining index I values of the shift signal in the time domain is:

Ι ₀ = [ 1 e {0,1,···«-1} and - /(mod n) e {0,1,· -·,η/ 4 + en)

I _X = i I e {0,1,···«-1} and n/2-i(modn) e {θ,1,...

J ₁

(mod/i) GI^.

16. The positioning device according to claim 12, characterized in that, after excluding the index value of the intermediate frequency domain signal in the time domain, the set of remaining index values is A, then the set

The intersection of A and the result of the previous iteration is the set S. The judgment subunit is also used to: The conditions that the first parameter needs to meet are: σ is a positive odd number that is not 1, and σ ≤ , where M is the size of the set S;

17. The positioning device according to claim 12 or 16, characterized in that, when the following two conditions are met at the same time, the judgment subunit determines to stop the iteration:

1^1 < cn. The judgment subunit calculates that the first parameter in the next iteration is the same as the first parameter in the previous iteration.

18. The positioning device according to claim 11, characterized in that the third unit is also used for:

If the estimated index value is , then the time delay is nT _s , where 7: is the sampling period.