CN103400115A - Wireless signal fingerprint matching method - Google Patents

Abstract

The invention discloses a wireless signal fingerprint matching method which comprises the following steps: S1, selecting a fingerprint record Fk in a fingerprint database; S2, determining public representation APs (access point) of a user fingerprint Fu and the Fk; S3, calculating the representation capacity coefficients of the public representation APs; S4, calculating the matching distance of the Fu and the Fk according to the difference of received signal strength of the public representation APs and the representation capacity coefficients; S5, updating k value, repeating the steps till the matching distances from all fingerprint records in the fingerprint database to the user fingerprint Fu; and S6, finding a fingerprint, with minimum matching distance to the user fingerprint Fu and the matching distance from adjacent fingerprints to the use fingerprint Fu meeting a certain threshold value as a target fingerprint of the user fingerprint Fu, wherein a corresponding position is the user position. The method can effectively prevent mistaken match by means of a ring positioning method, so that the matching accuracy is improved. The problem that the fingerprint matching precision is not high caused by instability of the APs is solved by means of a robust rule technology.

Description

A kind of wireless signal finger print matching method

Technical field

The present invention relates to the wireless indoor field of locating technology, relate in particular to a kind of wireless signal finger print matching method that is applied to indoor accurate position.

Background technology

The extensively large-scale promotion universal and wireless device of smart mobile phone has expedited the emergence of the research of locating about wireless indoor in a large number.The indoor orientation method of most utilizes existing WAP in environment (Access Point, AP) (as the access point of the wireless technologys such as WiFi, GSM, ZigBee) to realize location.Easily acquired due to received signal strength (Received Signal Strength, RSS), it becomes the most frequently used physical features.Received signal strength for each AP can directly read from Wireless Communication Equipment usually.Adopt wireless signal to become the most widely used indoor orientation method as the method for position feature, claim again indoor positioning or fingerprint location based on fingerprint.

The wireless fingerprint localization method was divided into for two stages usually: training and operation.In the training stage, need to carry out on-site land survey to localizing environment.In this process, the slip-stick artist records the RSS fingerprint by each position in area-of-interest and sets up a fingerprint database.Being about to fingerprint and relative position is recorded in database together.In the operation phase, when the user sent the request of a position enquiring, location algorithm utilized the present RSS fingerprint retrieval fingerprint database of this user and returns to the record of optimum matching, and the position that this record is corresponding is as user's location estimation.

Fingerprint matching algorithm directly concerns positioning precision.Because wireless signal is propagated and is subject to the impacts such as multipath, refraction, reflection under the indoor environment of complexity, add the dynamic of environment, not unique problem on unstable on wireless signal fingerprint life period, space.Particularly, main manifestations is:

1) the isospace position may detect similar fingerprint.In other words, the same user fingerprints may all have higher similarity with remote two locational fingerprints in space, thereby brings uncertainty for the location estimation of user fingerprints.

2) instability of AP, received signal strength presents fluctuation by a small margin at short notice, in long-time, present significantly and changes.And the stability out that different AP show is different.

In existing received signals fingerprint matching technique, all do not consider above-mentioned factor, the problems such as coupling or matching precision are lower often make the mistake.

Summary of the invention

(1) technical matters that will solve

Technical matters to be solved by this invention is: how a kind of wireless signal finger print matching method is provided, solves matching accuracy and the not high problem of precision in prior art.

(2) technical scheme

In order to solve the problems of the technologies described above, on the one hand, the invention provides a kind of wireless signal finger print matching method, comprise the steps:

S1, in fingerprint database selected fingerprint recording F _k

S2, determine user fingerprints F _uWith F _kEach public sign AP;

S3, calculate the sign capacity factor of each described public sign AP;

S4, according to the poor and described sign capacity factor of the received signal strength of above-mentioned each public sign AP, calculate F _uWith F _kMatching distance;

S5, renewal k value, repeat above-mentioned steps, until obtain user fingerprints F _uMatching distance with all fingerprint recordings in fingerprint database;

S6, find out and user fingerprints F _uEuclidean distance minimum and adjacent fingerprint and user fingerprints F _uMatching distance meet the fingerprint of certain threshold value as user fingerprints F _uTarget fingerprint, corresponding position is customer location;

The poor Δ F=[x that is labeled as of the received signal strength of described each public sign AP _i, i=1,2 ..., Q], wherein Q is the number of public sign AP.

Preferably, after step S3, also comprise step:

S3B, to described F _uWith F _kThe poor stipulations of carrying out of received signal strength of corresponding public sign AP.

Particularly, the specific implementation step of described S3B is:

S3B1, according to the least square mean value theorem, described Δ F is generated and returns estimated value;

S3B2, judge the poor whether exceptional value of the received signal strength of each public sign AP;

It is poor that S3B3, the recurrence estimated value that obtains with step S3B1 substitute the received signal strength of corresponding abnormal public sign AP.

Particularly, described step S3B2 judges poor whether exceptional value is specially for the received signal strength of each public sign AP:

Judge the poor x of received signal strength of each public sign AP _i(i ∈ 1,2 ..., Q}) whether corresponding estimation residual error surpasses the threshold value of setting, if surpass this threshold value, judges x _iFor exceptional value; Otherwise be judged to be non-exceptional value.

Particularly, described step S3B2 judges poor whether exceptional value is specially for the received signal strength of each public sign AP:

According to x _i(i ∈ 1,2 ..., the poor x of resistance diagnosis index judgement received signal strength Q}) _iWhether be exceptional value.x _iResistance diagnosis index RD _iBe specially:

${\mathrm{RD}}_i=\frac{x_i}{{\mathrm{med}}_{j=1,...,Q}{x}_j}$

Wherein, med represents median.Work as RD _i<2.5 o'clock, x _iDo not belong to exceptional value; Work as RD _i>=2.5 o'clock, x _iBelong to exceptional value.

Further, F in described step S2 _uWith F _kPublic sign AP specifically following steps obtain by carrying out:

S21, delete F respectively _uWith F _kMiddle received signal strength is less than the AP of setting threshold, the F that obtains _u' and F _k', F wherein _uThe set of the AP of ' correspondence is F _kThe set of the AP of ' correspondence is

S22, right

With

Seek common ground, order

The number of AP in the expression common factor, if P=0 exports fingerprint F _uWith described fingerprint F _kDo not mate, upgrade the k value, get back to step S1;

If P ≠ 0, carry out S23;

S23, right

With Ask union, and all AP that concentrate are exactly user fingerprints F _uWith described F _kPublic sign AP.

Further, in described step S3, the sign capacity factor concrete steps of each described public sign AP of calculating are as follows:

S31, with the received signal strength of described public sign AP, again represent F _uWith F _k

S32, calculate each public sign AP and F _uPhysical distance D _u=[d _u,q, q=1,2 ..., Q], d _u,qRepresent q public sign AP and F _uPhysical distance;

Calculate each public sign AP and F _kPhysical distance D _k=[d _k,q, q=1,2 ..., Q], d _k,qRepresent q public sign AP and F _kPhysical distance;

S33, the d that obtains based on step S32 _u,qAnd d _k,q, q=1,2 ..., Q, calculate respectively q public sign AP for user fingerprints F _uWith F _kSign capacity factor ρ _u,qWith ρ _k,qAs follows:

${\mathrm{\&rho;}}_{t,q}=\frac{1}{d_{t,q}{\mathrm{\&Sigma;}}_t}$

Wherein, ${\mathrm{\&Sigma;}}_t={\mathrm{\&Sigma;}}_{j=1}^Q\frac{1}{d_{t,j}},$ t∈{u,k}；

S34, get the ρ that step S33 obtains _u,qAnd ρ _k,qIn larger value, as q F _uWith F _kThe sign capacity factor ρ of public sign AP _q, q=1,2 ..., Q.

Further, in described step S32, step is calculated d _u,qPerhaps d _k,qDetailed process be:

As can be known apart from path fading model (Log-normal Distance Path Loss) according to logarithm:

PL(d _q)＝PL ₀+10γlg(d _q)

Wherein, PL ₀The received signal strength when physical distance of an expression and q public sign AP is 1 meter, γ is the path attenuation index, PL (d _q) represent that with the physical distance of q public sign AP be d _u,qThe time received signal strength, PL (d _q) can be from F _uPerhaps F _kIn directly obtain;

Separate above-mentioned equation and can obtain d _u,qPerhaps d _k,qValue.

Particularly, F in described step S4 _uWith F _kThe matching distance of matching distance be calculated as follows:

$\mathrm{\&Phi;}(F_u,F_k)=\frac{Q}{P}\sqrt{{\mathrm{\&Sigma;}}_{q=1}^Q{\left({\mathrm{\&rho;}}_q{x}_q\right)}^2}$

Wherein, Q represents F _uWith F _kThe number of public sign AP, P represents F _uWith F _kMiddle received signal strength is more than or equal to the number of the common factor of the AP of setting threshold, ρ _qExpression F _uWith F _kThe sign capacity factor of the public sign AP of q, x _qExpression F _uWith F _kThe difference of received signal strength of the public sign AP of q.

Concrete, threshold value described in described step S6 is the maximal value of the matching distance between the fingerprint on wantonly two adjacent positions in fingerprint database.

Further, the adjacent fingerprint in described step S6 refers to: the fingerprint that the neighbouring sample point that records in described fingerprint database is corresponding;

Preferably, adjacent fingerprint is chosen the fingerprint of the neighbouring sample point of East, West, South, North four direction.

(3) beneficial effect

Wireless signal finger print matching method that the present invention puts down in writing has proposed the concept of delineation position, that in fingerprint database, determine and the fingerprint user fingerprints coupling, and the matching distance of its adjacent fingerprint and user fingerprints also will meet some requirements.With this, prevent the phenomenon of erroneous matching, improve the accuracy of coupling.

In the fingerprint matching process, the method that the present invention puts down in writing, do not use whole AP, and only select public sign AP that the sign ability is strong to reduce the complexity of matching process.Utilize robust stipulations technology to screen out RSS abnormal between two fingerprints to be matched poor, thereby solved the not high problem of fingerprint matching precision that the instability due to AP causes.

Simultaneously, the method is without any need for extra hardware device, also without revising on-site land survey or locating terminal, can with the general direct integrated use of each class methods at present, have very high universality.

After reading by reference to the accompanying drawings the detailed description of embodiment of the present invention, other advantage and disadvantages of the present invention will become clearer.

The accompanying drawing explanation

Fig. 1 is the steps flow chart schematic diagram of wireless signal finger print matching method in one embodiment of the present invention;

Fig. 2 is one embodiment of the present invention centre circle positioning principle schematic diagram;

Fig. 3 is that in embodiments of the invention two, the difference in signal strength of adding to abnormal public sign AP is carried out robust stipulations schematic diagram.

Embodiment

Below in conjunction with Figure of description and embodiment, the specific embodiment of the present invention is described in further detail.Following examples are only be used to the present invention is described, but are not used for limiting the scope of the invention.

For the ease of narration and explanation the specific embodiment of the present invention, the received signal strength of public sign AP is poor in following examples refers to: in two fingerprints to be matched, and the difference of the received signal strength of the same public sign AP that records respectively; AP and fingerprint F _kPhysical distance refer to: the distance between the position at AP place and the corresponding physical location of this fingerprint.

Embodiment mono-

As shown in Figure 1, the present embodiment has been put down in writing a kind of wireless signal finger print matching method, comprises the steps:

S1, at fingerprint database

In selected fingerprint recording F _k

Concrete, indoor wireless networks is comprised of a plurality of wireless apss usually, by at the described AP received signal strength of indoor scene exploration, can obtain the fingerprint database in localizing objects zone

.The exploration process is: at first according to certain density according to grid-like fashion select sampled point (as, every two meters arrange a sampling); Secondly, on each sampled point, record the received signal strength of each AP, the wireless signal fingerprint as this sampled point institute correspondence position, be stored in fingerprint database.That is to say, every fingerprint in fingerprint database is corresponding a physical location label accurately all.

Suppose that total N the wireless aps of locating area is respectively { AP ₁, AP ₂..., AP _N, fingerprint F _kCan be expressed as: F _k=[f _{K, 1}, f _{K, 2}..., f _k,N], f wherein _k,n(the expression of 1≤n≤N) F _kRepresented sampled point is to AP _nReceived signal strength, if sampled point does not receive the signal of some AP, received signal strength that should AP is designated as-100dBm.

S2, determine user fingerprints F _uWith above-mentioned F _kPublic sign AP, calculate the sign capacity factor of each public sign AP;

Usually, in fingerprint, the received signal strength of AP is stronger, illustrates that this AP is the closer to the represented position of this fingerprint.At the present embodiment, do not use the whole AP in fingerprint, and the stronger AP of only selective reception signal intensity can reduce effectively and calculate the complexity that matching distance is as public sign AP.

The finger print information when user sends the position enquiring request is designated as F _u=[f _{U, 1}, f _{U, 2}..., f _u,N], determine user fingerprints F _uWith described F _kPublic sign AP specifically comprise the following steps:

S21, delete user fingerprints F respectively _uWith described F _kMiddle received signal strength is less than the AP of setting threshold σ, the F that obtains _u' and F _k', F wherein _uThe set of the AP of ' correspondence is

F _kThe set of the AP of ' correspondence is

The value of described σ rule of thumb measured value obtains, and usually elects as-95dBm;

S22, right

With

Seek common ground, order

The number of AP in the expression common factor, if P=0 exports fingerprint F _uWith described fingerprint F _kDo not mate, upgrade the k value, get back to step S1;

If P ≠ 0, carry out S23;

S23, right With Ask union, note

Q≤N wherein,

In all wireless apss be exactly user fingerprints F _uWith described F _kPublic sign AP.

S3, calculate the sign capacity factor of each public sign AP;

By with the nearer AP of a certain positional distance, just larger to the sign capacity factor of this position.In the present embodiment the sign capacity factor of AP with the distance represent, be specially:

S31, to above-mentioned F _u' and F _k' expand, make F _u'=[f _u' _{, 1}, f _u' _{, 2}..., f _u' _{, Q}], f wherein _u' _{, q}(the expression of 1≤q≤Q) F _uRepresented physical location is to AP _q' received signal strength, if

Remember f _u' _{, q}=-100, unit is dBm;

Similar, make F _k'=[f _k' _{, 1}, f _k' _{, 2}..., f _k' _{, Q}], f wherein _k' _{, q}(the expression of 1≤q≤Q) F _kRepresented sampled point is to AP _q' received signal strength, if Remember f _k' _{, q}=-100, unit is dBm;

Make x _q=| f _u' _{, q}-f _k' _{, q}|, q=1,2 ..., Q, represent that public sign AP is at F _uWith F _kIn received signal strength poor, note Δ F=[x ₁, x ₂..., x _Q].

S32, calculating

In position and the F at each AP place _uThe physical distance of represented position.

Concrete, AP _q' (1≤q≤Q) to F _uRepresented position apart from d _u,qCan apart from path fading model (Log-normal Distance Path Loss), calculate according to logarithm:

PL(d _u,q)＝PL ₀+10γlg(d _u,q)

Wherein, PL ₀Expression and AP _q' the received signal strength of distance while being 1 meter, γ is the path attenuation index, PL (d _u,q) expression and AP _q' the distance be d _u,qThe time received signal strength, PL (d in the present embodiment _u,q)=f _u' _{, q}.

In like manner, can calculate

In position and the F at each AP place _kThe physical distance of represented position.

S33, the d that obtains based on above-mentioned steps _u,qCalculate AP _q' (q=1,2 ..., Q) for user fingerprints F _u'=[f _u' _{, 1}, f _u' _{, 2}..., f _u' _{, Q}] the sign capacity factor as follows:

${\mathrm{\&rho;}}_{u,q}=\frac{1}{d_{u,q}{\mathrm{\&Sigma;}}_u}$

Wherein, Be a normalized parameter, make F _u'=[f _u' _{, 1}, f _u' _{, 2}..., f _u' _{, Q}] in the sign capacity factor summation of each AP

In like manner, can calculate AP _q' (q=1,2 ..., Q) for user fingerprints F _k'=[f _k' _{, 1}, f _k' _{, 2}..., f _k' _{, Q}] sign capacity factor ρ _k,q, q=1,2 ..., Q.

S34, get the ρ that step S33 obtains _u,qAnd ρ _k,qIn larger value, as q F _uWith F _kThe sign capacity factor of public sign AP, i.e. ρ _q=max{ ρ _u,q, ρ _k,q, q=1,2 ..., Q.

S4, calculating F _uWith F _kMatching distance;

Based on above-mentioned steps, F _uWith F _kThe matching distance of matching distance be calculated as follows:

$\mathrm{\&Phi;}(F_u,F_k)=\frac{Q}{P}\sqrt{{\mathrm{\&Sigma;}}_{q=1}^Q{\left({\mathrm{\&rho;}}_q{x}_q\right)}^2}$

S5, renewal k, repeat above-mentioned steps, until obtain user fingerprints F _uMatching distance with all fingerprint recordings in fingerprint database;

S6, find out and user fingerprints F _uMatching distance minimum and surrounding fingerprint and user fingerprints F _uMatching distance meet the fingerprint of certain threshold value as user fingerprints F _uTarget fingerprint, corresponding position is customer location.

On the basis of above-mentioned steps, the present embodiment is introduced the concept of " delineation position ", improves positioning precision.As shown in Figure 2, the delineation position refers to, and in the fingerprint matching process, does not use the mode of single-point coupling, and (fingerprint that is about in user fingerprints and fingerprint database mates one by one, finds the most similar target fingerprint), and adopt the multiple spot coupling.The multiple spot coupling, for single-point, will guarantee that not only user fingerprints is similar to target fingerprint while referring to coupling, will guarantee that simultaneously the fingerprint that user fingerprints is corresponding with the target fingerprint adjacent position is also comparatively close.Particularly, given user fingerprints F _u, to each the fingerprint F in fingerprint database _k, remember that the fingerprint of four direction up-sampling point is F around it _K1, F _K2, F _K3And F _K4, according to above-mentioned steps, can obtain Φ (F _u, F _x), F wherein _x∈ { F _k, F _K1, F _K2, F _K3, F _K4,

When

And

$\&ForAll;F_x\&Element;\{F_{k1},F_{k2},F_{k3},F_{k4}\},\mathrm{\&Phi;}(F_u,F_x)<\mathrm{\&epsiv;}$

The time, selected F ^*For target fingerprint, F ^*Corresponding position is target location.Wherein, ε is the adjacent fingerprint similarity threshold, usually the print database

In the maximal value of matching distance between fingerprint on any two adjacent positions.

If meet the target fingerprint of above condition, do not exist, within judging that the user is not in the corresponding locating area scope of current fingerprint database, can't return to user's position.

In this step of the present embodiment, for each the fingerprint F in fingerprint database _k, around it, fingerprint of four direction up-sampling point can be adjacent sampled point on east, south, west, north four direction, can be also adjacent sampled point on the southeast, northeast, southwest, northwest four direction.Further, also can not get the fingerprint of four direction on every side in other embodiments of the invention, change into and get the nearest fingerprint of adjacent fingerprint middle distance, or only get the fingerprint of left and right adjacent sampled point or only get the fingerprint of forward and backward adjacent sampled point.Those skilled in the art it should be understood that can also have other modes to choosing of sampled point fingerprint on every side, also should be understood to belong to invention which is intended to be protected.

Embodiment bis-

On the basis of embodiment mono-, further comprising the steps of before step S4 after step S3:

S3B, to the poor robust stipulations of carrying out of the received signal strength of abnormal public sign AP.

Due to the stability difference of each AP, different time surveys identical sampled point, and the sampling fingerprint that obtains may be different.Especially, if the stability of some AP is very poor, there will be two kinds of situations to the exploration the possibility of result of this AP received signal strength so: a kind of is at same sampled point, larger fluctuation appears in the received signal strength of this AP at short notice, another kind is two employing points that position approaches very much, the received signal strength of this AP that surveys but has very big-difference, and both of these case all can produce a very large impact the matching result of user fingerprints.The AP of this poor stability just is called abnormal AP.

If abnormal AP, as the public sign AP of fingerprint to be matched, will produce abnormal received signal strength poor, and then the matching distance of fingerprint to be matched is caused to larger error.The adverse effect that causes in order to eliminate abnormal AP, match user fingerprint accurately, with regard to the poor stipulations of carrying out of abnormal received signal strength that need abnormal AP to cause.The present embodiment adopts robust stipulations technology to revise abnormal received signal strength is poor.

As shown in Figure 3, the effect of robust stipulations be when most RSS differences all hour, the great exceptional value of minority difference can be adjusted to less estimated value, and when most RSS differences were all larger, the minimum exceptional value of minority difference was adjusted to larger estimated value.The concrete steps of robust stipulations are as follows:

S3B1, intensity difference vector Δ F=[x to received signal ₁, x ₂..., x _Q] regression estimator of generation

Obtain one group of estimation to Δ F $\mathrm{\&Delta;}\hat{F}=[{\hat{x}}_1,{\hat{x}}_2,...,{\hat{x}}_Q],$ Wherein ${\hat{x}}_i=x_i\&CenterDot;\mathrm{\&theta;}+e,$ i＝1,2,...,Q。

According to the least square mean value theorem, the optimum target of setting the recurrence estimation is:

$\underset{\widehat{\mathrm{\&theta;}}}{\min }\underset{i}{\mathrm{med}}{r_i}^2$

Wherein med represents median,

For estimating residual error;

The solvable θ value of above-mentioned optimization formula and e value are arranged, thereby obtain

I=1,2 ..., Q.

S3B2, to abnormal received signal strength is poor, revise;

Judge whether received signal strength is poor abnormal, can adopt following two kinds of modes:

A kind of is the poor x of each received signal strength of judgement _i(i ∈ 1,2 ..., Q}) corresponding estimation residual error r _iWhether surpass the threshold value of setting, if surpass this threshold value, judge x _iFor exceptional value; Otherwise be judged to be non-exceptional value.

Another kind is to adopt the poor x of resistance diagnosis (Resistant Diagnostic) index judgement received signal strength _i(i ∈ 1,2 ..., whether be Q}) exceptional value.x _iResistance diagnosis index RD _iBe specially:

${\mathrm{RD}}_i=\frac{x_i}{{\mathrm{med}}_{j=1,...,Q}{x}_j}$

Wherein, med represents median.Work as RD _i<2.5 o'clock, x _iDo not belong to exceptional value; Work as RD _i>=2.5 o'clock, x _iBelong to exceptional value.

S3B3, according to above-mentioned two kinds of decision methods, the received signal strength of note after stipulations is poor is

, i ∈ 1,2 ..., Q}, so

Step S4 in embodiment mono-changes into: poor based on the received signal strength after stipulations, the AP that calculates in conjunction with previous step characterizes capacity factor, F _uWith F _kThe matching distance of matching distance be calculated as follows:

$\mathrm{\&Phi;}(F_u,F_k)=\frac{Q}{P}\sqrt{{\mathrm{\&Sigma;}}_{q=1}^Q{\left({\mathrm{\&rho;}}_q{\tilde{x}}_q\right)}^2}$

Other steps in embodiment 1 are constant.

To the poor stipulations of carrying out of the received signal strength of AP, can eliminate the impact of abnormal AP on matching result, greatly improve matching precision.

The above is only the preferred embodiment of the present invention; it should be pointed out that for those skilled in the art, under the prerequisite that does not break away from the technology of the present invention principle; can also make some improvement and modification, these improve and modification also should be considered as protection scope of the present invention.

Claims (11)

1. a wireless signal finger print matching method, is characterized in that, comprises the following steps:

S1, in fingerprint database selected fingerprint recording F _k

S2, determine user fingerprints F _uWith F _kEach public sign AP;

S3, calculate the sign capacity factor of each described public sign AP;

S4, according to the poor and described sign capacity factor of the received signal strength of above-mentioned each public sign AP, calculate F _uWith F _kMatching distance;

S5, renewal k value, repeat above-mentioned steps, until obtain user fingerprints F _uMatching distance with all fingerprint recordings in fingerprint database;

S6, find out and user fingerprints F _uMatching distance minimum and adjacent fingerprint and user fingerprints F _uMatching distance meet the fingerprint of certain threshold value as user fingerprints F _uTarget fingerprint, corresponding position is customer location;

The poor Δ F=[x that is labeled as of the received signal strength of described each public sign AP _i, i=1,2 ..., Q], wherein Q is the number of public sign AP.

2. the method for claim 1, is characterized in that, after step S3, also comprises step:

S3B, to described F _uWith F _kThe poor stipulations of carrying out of received signal strength of each public sign AP.

3. method as claimed in claim 2, is characterized in that, the specific implementation step of described S3B is:

S3B1, according to the least square mean value theorem, described Δ F is generated and returns estimated value;

S3B2, judge the poor whether exceptional value of the received signal strength of each public sign AP;

It is poor that S3B3, the recurrence estimated value that obtains with step S3B1 substitute the received signal strength of corresponding abnormal public sign AP.

4. method as claimed in claim 3, is characterized in that, described step S3B2 judges poor whether exceptional value is specially the received signal strength of each public sign AP:

Judge the poor x of received signal strength of each public sign AP _i(i ∈ 1,2 ..., Q}) whether corresponding estimation residual error surpasses the threshold value of setting, if surpass this threshold value, judges x _iFor exceptional value; Otherwise be judged to be non-exceptional value.

5. method as claimed in claim 3, is characterized in that, described step S3B2 judges poor whether exceptional value is specially the received signal strength of each public sign AP:

According to x _i(i ∈ 1,2 ..., the poor x of resistance diagnosis index judgement received signal strength Q}) _iWhether be exceptional value.x _iResistance diagnosis index RD _iBe specially:

${\mathrm{RD}}_i=\frac{x_i}{{\mathrm{med}}_{j=1,...,Q}{x}_j}$

Wherein, med represents median.Work as RD _i<2.5 o'clock, x _iDo not belong to exceptional value; Work as RD _i>=2.5 o'clock, x _iBelong to exceptional value.

6. the method for claim 1, is characterized in that, F in described step S2 _uWith F _kPublic sign AP specifically following steps obtain by carrying out:

S21, choose F respectively _uWith F _kMiddle received signal strength is more than or equal to the AP of setting threshold, F _uThe set of corresponding AP is

F _kThe set of corresponding AP is

S22, right

With

Seek common ground, make P represent to occur simultaneously in the number of AP, if P=0 exports fingerprint F _uWith described fingerprint F _kDo not mate, upgrade the k value, get back to step S1;

If P ≠ 0, carry out S23;

S23, right

With

Ask union, and all AP that concentrate are exactly F _uWith F _kPublic sign AP.

7. the method for claim 1, is characterized in that, the sign capacity factor concrete steps of calculating each described public sign AP in described step S3 are as follows:

S31, with the received signal strength of described public sign AP, again represent F _uWith F _k

S32, calculate each public sign AP and F _uPhysical distance D _u=[d _u,q, q=1,2 ..., Q], d _u,qRepresent q public sign AP and F _uPhysical distance;

Calculate each public sign AP and F _kPhysical distance D _k=[d _k,q, q=1,2 ..., Q], d _k,qRepresent q public sign AP and F _kPhysical distance;

S33, the d that obtains based on step S32 _u,qAnd d _k,q, q=1,2 ..., Q, calculate respectively q public sign AP for user fingerprints F _uWith F _kSign capacity factor ρ _u,qWith ρ _k,qAs follows:

${\mathrm{\&rho;}}_{t,q}=\frac{1}{d_{t,q}{\mathrm{\&Sigma;}}_t}$

Wherein, ${\mathrm{\&Sigma;}}_t={\mathrm{\&Sigma;}}_{j=1}^Q\frac{1}{d_{t,j}},$ t∈{u,k}；

S34, get the ρ that step S33 obtains _u,qAnd ρ _k,qIn larger value, as q F _uWith F _kThe sign capacity factor ρ of public sign AP _q, q=1,2 ..., Q.

8. method as claimed in claim 7, is characterized in that, in described step S32, step is calculated d _u,qPerhaps d _k,qDetailed process be:

As can be known apart from the path fading model according to logarithm:

PL(d _q)＝PL ₀+10γlg(d _q)

Wherein, PL ₀The received signal strength when physical distance of an expression and q public sign AP is 1 meter, γ is the path attenuation index, PL (d _q) represent that with the physical distance of q public sign AP be d _u,qThe time received signal strength, PL (d _q) can be from F _uPerhaps F _kIn directly obtain;

Separate above-mentioned equation and can obtain d _u,qPerhaps d _k,qValue.

9. method as described as any one in claim 1 to 8, is characterized in that, F in described step S4 _uWith F _kMatching distance be calculated as follows:

$\mathrm{\&Phi;}(F_u,F_k)=\frac{Q}{P}\sqrt{{\mathrm{\&Sigma;}}_{q=1}^Q{\left({\mathrm{\&rho;}}_q{x}_q\right)}^2}$

Wherein, P represents F _uWith F _kMiddle received signal strength is more than or equal to the number of the common factor of the AP of setting threshold, ρ _qExpression F _uWith F _kThe sign capacity factor of the public sign AP of q, x _qExpression F _uWith F _kThe difference of received signal strength of the public sign AP of q.

10. method as described as any one in claim 1 to 8, is characterized in that, threshold value described in described step S6 is the maximal value of the matching distance between the fingerprint on wantonly two adjacent positions in fingerprint database.

11. method as described as any one in claim 1 to 8, is characterized in that, the adjacent fingerprint in described step S6 refers to: the fingerprint that the neighbouring sample point that records in described fingerprint database is corresponding;

Adjacent fingerprint is chosen the fingerprint of the neighbouring sample point of East, West, South, North four direction.

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