CN1617601A - Method for producing power time delay distribution - Google Patents

Abstract

This invention discloses a generation method for power time delay distribution including the following steps: (a) taking the minimum distance resolution as the resolved distance unit and computing the appearance ratio of power time delay distribution based on the distribution number of maximum attached time delay and total number to further get a resolved distance unit set then to determine the appearance time of said set internal diameter, (b) generating power of each appearance diameter in said set according to the set and diameter appearance time got in step (a) acquiring the power decline of the diameter based on the power of the diameter in step (b).

Description

The production method that a kind of power time delay distributes

Technical field

The present invention relates to the location technology of wireless system, be meant the production method of a kind of non-visible channel (NLOS) power time delay distribution that is used to locate especially.

Background technology

In cellular mobile station navigation system or global positioning system (GPS), because blocking or the fluctuating of landform of surface structures, cause framing signal will be subjected to the influence of multipath inevitably, therefore, from the angle of transmission path signal channel is divided into visual channel (path), will definitely looks three kinds of channel (LOS) and non-visible channels.At present, the NLOS of signal propagates has become a kind of universal phenomenon, and existing non-visible channel power time delay distributes or the production method that is called the impulse response of non-visible channel has two kinds:

A kind ofly proposed to T1P1.5 forum in 1998 by Ericsson (Ericsson) company, proposed scheme be numbered T1P1.5/98-110, name is called " Evaluation of Positioning System ", this is the production method that a kind of non-visible channel power time delay that aims at mobile position estimation emulation and set up distributes, and this method is commonly used.The production method that the non-visible channel power time delay that Ericsson proposed distributes, form by following basic step:

The first step: produce the time delay expansion according to the time delay extended model earlier, this time delay extended model is:

τ _rms＝T ₁d ^εy

Wherein, τ _RmsRoot-mean-square value for the time delay expansion; T ₁It is the intermediate value of the time delay expansion during apart from d=1km; ε is the index with distance dependent; Y is a lognormal variable, that is to say: Y=10logy is a Gaussian random variable that standard deviation is σ.

Second step: calculate the maximum delay expansion then, the computing formula of this maximum delay expansion is:

τ _max＝3.58τ _rms

The 3rd step: the maximum delay expansion according to calculating produces the power time delay distributed model.

Such as: produce 20 footpaths, its additional time delay τ _i[0, τ _Max] between and obey evenly and distribute, the additional time delay size in each footpath is carried out ascending order arranges; Calculate and τ _iCorresponding P _i, and to P _iCarry out normalization, here P _iThe power in i footpath, P _i, P _nAlso be used for representing the probability of occurrence of footpath, based on context can distinguish its implication clearly in the distinguishable unit of minimum.

The 4th step: regulate the power time delay distribution according to the power time delay distributed model that is produced.

Because P _iNormalization can be calculated the average power time delay according to formula (1), and utilizes formula (2) to calculate the pairing time delay expansion of this average power time delay distribution:

$\mathrm{MeanDelay}=\frac{\mathrm{\Σ}{p}_i\·{\mathrm{\τ}}_i}{\mathrm{\Σ}{p}_i}=\mathrm{\Σ}{p}_i\·{\mathrm{\τ}}_i---\left(1\right)$

$\mathrm{RMSDelaySpread}=\mathrm{\Σ}\sqrt{p_i\·{({\mathrm{\τ}}_i-\mathrm{MeanDelay})}^2}---\left(2\right)$

Adjust the power time delay distribution and make the time delay expansion of this channel and the τ in the first step time delay extended model _RmsBe complementary, the adjustment formula is: τ _i=(τ _i* τ _Rms) ÷ RMSDelaySpread.

The 5th step: last, use subwave to delineate its fading characteristic to every footpath.

Another kind is a method related to the present invention, this method is called " Statistical Channel Impulse Response Models for Facrory and Open Plan BuildingRadio Communication System Design " by people such as T.S.Rappaport in name, IEEE Trans Comm, Vol.39, No.5, May1991, propose in pp794～807, the application target of the method that the generation non-visible channel power time delay that people such as T.S.Rappaport provide distributes is communication emulation, though this method can not satisfy the specific demand of mobile position estimation, but because this method has similarity with institute of the present invention extracting method on principle, so it is discussed at this.

The non-visible channel power time delay distribution that people such as T.S.Rappaport provide or the method for title channel impulse response, form by following basic step:

The first step: total probability of occurrence in the footpath of non-visible channel in different additional time delay interval is described in segmentation, promptly obtains the probability of occurrence curve in the footpath shown in 101 among Fig. 1;

Second step: according to the probability of occurrence shown in the curve 101, in each the distinguishable unit in corresponding additional time delay interval, the probability of happening in the footpath that provides by curve 101 produces the footpath;

The 3rd step: the power statistic characteristic in the footpath that records according to the field, give corresponding performance number to the footpath that second step produced.

At above-mentioned two kinds of schemes as can be seen, the non-visible channel power time delay that structure mobile position estimation emulation platform uses distributes, the target of being pursued with the distribution of non-visible channel power time delay with the structure communication is different, and this just must cause the difference on the modeling method.For communication emulation, to τ _RmsThe accuracy of time delay extended description is the target that modeling is pursued; And for location simulation, do not need to be concerned about τ _RmsThe accuracy of describing, produce the needed non-visible channel power time delay distribution of location simulation and will satisfy following two targets simultaneously: 1) the first directly accuracy of the time of advent, this is a decision positioning accuracy most important parameters, for non-visible channel, the first non-visible channel that directly is the time of advent is introduced error, when therefore the power time delay of using in the emulation of generation mobile position estimation distributes, guarantee the accuracy of the first footpath description time of advent; 2) accuracy of the first footpath time of advent and the statistical law that exists between the arrival frequency in each footpath thereafter, this is to carry out head footpath time of advent, it is the foundation that non-visible channel is introduced estimation error, therefore, when the power time delay that produces mobile position estimation emulation use distributes, this rule be described exactly.

So, from satisfying the angle of above-mentioned target, there is following shortcoming in prior art as can be seen: the non-visible channel power time delay distribution production method that people such as mobile position estimation channel model that Ericsson company proposes and T.S.Rappaport provide does not all provide and carries out carrying out under accurate LOS channel and the NLOS channel the needed information of (TOA) the additional time delay estimation error time of advent.Originally, under NLOS channel and accurate LOS channel, there is correlation between the power time delay characteristic in the some footpaths after the first footpath and the first footpath TOA additional time delay error, utilize this correlation can estimate and correct TOA additional time delay error under NLOS channel and the accurate LOS channel, but the existing channel model does not embody this correlation.

Summary of the invention

In view of this, main purpose of the present invention is to provide a kind of production method of power time delay distribution, make it can guarantee the accuracy that time of arrival (toa) is described, and can demonstrate fully the correlation between first footpath TOA additional time delay error and the some thereafter footpaths power time delay characteristic.

For achieving the above object, technical scheme of the present invention is achieved in that

The production method that a kind of power time delay distributes, this method may further comprise the steps:

A. with minimum range resolution as distinguishable range unit, power time delay distribution number and gross power time delay distribution number according to maximum additional time delay calculate the appearance ratio that power time delay distributes, and further obtain distinguishable range unit set, determine going out now of this set internal diameter then;

B. going out now of distinguishable range unit set that is obtained according to step a and footpath produces in this set every and power directly occurs;

C. the power in the footpath that obtains according to step b obtains the power fading in footpath.

In the such scheme, step a further comprises:

A1. according to the power time delay distribution number and the gross power time delay distribution number of the maximum additional time delay of difference, determine the appearance ratio R (p of the power time delay distribution of Different Diameter probability of occurrence Pn _n);

A2. with the possible value space of Pn as sample space, the resulting ratio R (p that occurs of step a1 _n) as the probability of occurrence of Pn, determine to need to produce the Pn of certain power time delay distribution;

A3. with the determined Pn of step a2 as probability of happening, carry out at least one heavy Bei Nuli test, will the distinguishable range unit e of the Bei Nuli test number (TN) k correspondence of incident takes place at every turn _kForm a distinguishable range unit set as element, and the element number that will gather is as the number in footpath on the current power time delay distribution; Wherein the number of times of Bei Nuli test is the number of the distinguishable range unit of current maximum additional time delay correspondence;

A4. determining step a3 generates going out now of set internal diameter.

Wherein, the appearance ratio R (P of the distribution of the power time delay described in the step a1 _n) be: maximum additional time delay τ _{Max_n}Power time delay distribution number N _nDivided by total power time delay distribution number N.

In the such scheme, under non-visible channel, further comprise the now that goes out of determining the footpath described in the step a4: at least two strips are directly put into current distinguishable range unit, directly obtain going out now of current distinguishable range unit internal diameter in the position of the correlation peak of actings in conjunction generation according to all sons.Under accurate non-visible channel, determine going out now of footpath described in the step a4: place strip footpath as first footpath in diffraction time delay error end, position in the first distinguishable range unit that head directly occupies except that placing first footpath is put into the son footpath beyond the first footpath at random, and the amplitude maximum in first footpath; Directly obtain going out now of current distinguishable range unit internal diameter in the position of the correlation peak of actings in conjunction generation according to all sons.

Under non-visible channel, described in the step a4 is directly put into current distinguishable range unit and is: with all the son footpaths that will put at distinguishable range unit e _kIn put at random according to even distribution or normal distribution form.Perhaps, describedly son is directly put into current distinguishable range unit be: distinguishable range unit e _kBe divided into one with top by the number that will put into the footpath, put into a footpath at random according to even distribution or normal distribution form in every part; Or, with distinguishable range unit e _kBe divided into one with top by the number that will put into the footpath, more every footpath be positioned over the fixed position of every part respectively.

In the such scheme, the power A in each footpath in the distinguishable range unit set described in the step b _kIn (0.5-1.5), produce according to even distribution; Or according to $A_k=V_k+0.1*V_k{e}^{-\frac{{6t}_k}{{\mathrm{\τ}}_{\max \_k}}}$ Produce; Or according to $A_k=V_k{e}^{-\frac{{6t}_k}{{\mathrm{\τ}}_{\max \_k}}}$ Produce; V wherein _kBe the stochastic variable that in (0.5-1.5), produces, t according to even distribution _kBe specifically going out now of distinguishable range unit set internal diameter.

In the such scheme, obtain the power fading in footpath described in the step c and adopt the mode of subwave stack to realize.

The production method that power time delay provided by the present invention distributes has following advantage and characteristics:

1) the present invention determines that by the arrival probability in the footpath of decomposition whether the footpath occurs, and so can guarantee the accuracy to the time of arrival (toa) description, and physical significance is clearer and more definite, realizes simpler in certain distinguishable range unit.

2) the present invention's power of having provided a kind of non-visible channel footpath is determined method, and this method is surveyed the result based on the field of non-visible channel, at a specific maximum additional time delay τ _{Max_n}In the scope, in 0～15 footpath, with the footpath power abstract along the distribution of additional time delay (Excess Delay) be a random process stably, so both guaranteed in the mobile position estimation emulation to the authenticity of NLOS error analysis that it is complicated that the consistent modeling that causes of result is surveyed in the field of having avoided painstakingly pursuing the distribute power in footpath and certain specific region again.

3) the present invention's NLOS error from mobile position estimation emulation specific needs of correcting performance verification constructs the channel model of following 2 of a kind of comprehensive embodiment: the regularity that first point, first footpath are influenced by its reflection that comprises footpath; Second point, the regularity that exists between the power time delay characteristic in reflection footpath and the first footpath TOA additional time delay error is utilized this channel model of being constructed, and can further estimate and correct TOA additional time delay error under NLOS channel and the accurate LOS channel.

Description of drawings

Fig. 1 (a)～(e) is the interval schematic diagram that the equiprobability in footpath on the non-visible channel additional time delay axle occurs;

Fig. 2 is for producing the basic procedure schematic diagram that the non-visible channel power time delay distributes;

Fig. 3 is for producing the handling process schematic diagram that now in footpath;

Fig. 4 goes out definite process schematic diagram of now for the footpath;

Fig. 5 is for determining the handling process schematic diagram of instantaneous fading amplitude directly.

Embodiment

The present invention has provided the production method of the non-visible channel power time delay distribution that is used for mobile position estimation emulation, this method be based on survey the NLOS environment that disclosed down the footpath rule that probability of occurrence showed propose, analyze the NLOS channel footpath rule that probability of occurrence showed down below earlier:

As shown in Figure 1, curve 101 among Fig. 1 (a) is document G.L.Turin, et al, ' A Statistical Modelof Urban Multipath Propagation ', IEEE Trans on Vehicular Tech Vol.VT-21, No.1, Feb.1972, the typical N LOS environment that pp.1～9 provide is the probability of occurrence curve in footpath down, and the preparation method of this curve is:

1) is unit with minimum range resolution or temporal resolution T, additional time delay is divided into several uniformly-spaced interval T from the near to the remote successively _i, here, described minimum range resolution is generally the half-power width of test pulse or the chip width of frequency expansion sequence;

2) at each minimum distinguishable interval T _iIn, total N the power time delay that obtains in the statistical measurement distributes and go up the number M in the footpath that occurs in this interval _i

3) can calculate under this typical N LOS environment the probability of occurrence curve 101 in footpath according to formula (3).

$P_i=\frac{M_i}{N}---\left(3\right)$

Curve 101 shows: between a given zone of additional time delay front portion, i.e. and 0～CPL1 in the corresponding diagram 1 (a), in each minimum distinguishable range unit, the probability of occurrence in footpath is approximately equalised.Corresponding diagram 1 (a) just is meant in CPLn (CPL, Constant probability length) the distinguishable range unit of individual minimum, the probability of occurrence approximately equal in footpath.

In order to obtain being applicable to the production method of non-visible channel mobile position estimation emulation power demand time delay distribution, need do further to decompose according to following method to curve 101:

Suppose in the survey on the scene that the different maximum additional time delay of acquisition is τ _{Max_n}(n ∈ 1,2,3 ...) the number that distributes of power time delay be N _n, and think at different τ _{Max_n}In the corresponding CPLn minimum distinguishable range unit, each distinguishable range unit is from N _nThe number approximately equal in the footpath that individual power time delay is obtained on distributing, then the number in this footpath is designated as m _n, just can obtain at the maximum additional time delay of difference according to formula (4) is τ _{Max_n}One group of power time delay distribute on, each distinguishable range unit T _iIn, the probability of occurrence p in footpath _n:

p _n＝m _n/N _n (4)

Wherein, P _nBe exactly and different maximum additional time delay τ _{Max_n}The probability of occurrence in footpath during corresponding power time delay distributes, as shown in Fig. 1 (b)～(e), curve 102a, 103a, 104a and 108a are respectively and τ _{Max_2}, τ _{Max_3}, τ _{Max_4}And τ _{Max_8}Corresponding power time delay distributes and goes up the probability of occurrence P in footpath _nCan calculate probability of occurrence according to formula (5) is P _nPower time delay distribute shared ratio R (p during the total power time delay that obtains distributes in whole is surveyed _n):

R(p _n)＝N _n/N (5)

If respectively with each τ _{Max_n}Corresponding M _nDivided by total power time delay distribution number N, just can obtain probability of occurrence is P _nPower time delay distribute to total probability of occurrence P _iContribution amount P (P _n), as shown in Equation (6):

P(P _n)＝m _n/N (6)

Curve 102a, 103a among Fig. 1 (a), 104a ... 108a is exactly P (P _n) profile, P (P _n) and P _iThe pass be:

P _i＝∑ _n＝1:kP(P _n)?(7)

In the formula (7), k is the τ that divides in the actual treatment _{Max_n}Number.When i less than τ _{Max_1}During corresponding CPL1, P _iBe constant P, as i during greater than CPL1 and less than CPLmax, P _iWith τ _{Max_n}In n increase and reduce, decrease is P (P _n)=m _n/ N.Here, CPLmax is meant that maximum among CPL1～CPLn CPL.

The probability of occurrence that above-mentioned the analysis showed that, total footpath probability of occurrence curve 101 can be decomposed into many groups footpath is p _n=m _n/ N _nCombination, and, p _nAt its corresponding τ _{Max_n}In each minimum distinguishable range unit in the scope is approximately equalised, and the present invention that Here it is tests one of foundation that produces the distribution of non-visible channel power time delay according to the heavy Bei Nuli of N.

Another is according to being: a survey shows that between different distinguishable range units the appearance in footpath can be similar to the incident of regarding separate as.

Based on above-mentioned principle analysis, the production method that non-visible channel power time delay of the present invention distributes as shown in Figure 2, comprises three basic steps:

Step 201: produce going out now of footpath.

Step 202: gather going out now of E and every footpath according to the distinguishable range unit that step 201 obtained, produce every power that the footpath occurs in this set.

Power A to each the bar footpath in the distinguishable range unit set E that the footpath occurs _k, its power can produce with several different methods, as: 1) A _kIn (0.5-1.5), produce according to even distribution; 2) produce according to formula (8):

$A_k=V_k+0.1*V_k{e}^{-\frac{{6t}_k}{{\mathrm{\τ}}_{\max \_k}}}---\left(8\right)$

3) produce according to formula (9):

$A_k=V_k{e}^{-\frac{{6t}_k}{{\mathrm{\τ}}_{\max \_k}}}---\left(9\right)$

In formula (8), (9), V _kBe the stochastic variable that in (0.5-1.5), produces according to even distribution, t _kBe e _kSpecifically going out now of internal diameter.

Step 203:, promptly produce the power fading in footpath with the fading characteristic in the synthetic footpath of subwave.

By above three steps, the distribution that can produce the power time delay under the non-visible channel.

In the step 201 of above-mentioned steps, as shown in Figure 3, further comprise four sub-steps:

Step 301: utilize formula (5) to determine different P _nThe appearance ratio R (P that distributes of power time delay _n);

Step 302: P _nPossible value space is as sample space, with R (P _n) as P _nProbability of occurrence, produce a p randomly _n(n ∈ 1,2 ... CPLmax), just, according to p _nPossible value space and R (p _n), determine a Pn specific, that need the generation power time delay to distribute;

Step 303: with the p of step 302 generation _nAs probability of happening, with τ _{Max_n}The number CPLn of corresponding distinguishable range unit does the heavy Bei Nuli test of N, wherein N=CPLn as the number of times of independent experiment.If incident k (k ∈ 1,2 ... CPLn) take place in the inferior test, just at k distinguishable range unit e _kIn the footpath appears, in CPLn independent experiment, e directly will appear _kConstitute a set E, the element number among the E is exactly that the number in footpath is gone up in this power time delay distribution;

Step 304: determine in the distinguishable range unit set E that the going out now of footpath is that is: at all distinguishable range unit e in the appearance footpath that step 303 is determined _kIn, further determine which the time engrave and the footpath occurs.The specific implementation method of this step is: the result that some strips are directly synthetic is regarded as in every footpath, as: the son footpath by two or more is synthetic.Directly be that example is illustrated to be decomposed into two strips below:

Referring to shown in Figure 4, for the situation that directly is made of a footpath two strips, among Fig. 4, solid line 401 is illustrated in the maximum delay spreading range, by distinguishable range unit e _kThe sequence that constitutes; Heavy line 402 and 403 constitutes distinguishable range unit e ₁In the footpath; Solid line 404 and 405 constitutes distinguishable range unit e ₂In the footpath; T represents distinguishable range unit e _kWidth, unit is a chip.

Under NLOS channel and accurate LOS channel, in order to embody the error component that introduce in radio wave diffraction path under the accurate LOS channel, Fig. 4 provide by distinguishable range unit e _kThe sequence 401 that constitutes, its starting point need produce one according to the diffraction tracking error and move after at random, then, produces going out now of NLOS channel and accurate LOS channel footpath respectively according to step 304-1 and 304-2 again.

Step 304-1:NLOS channel is the generation of the due in footpath down, is that example describes with two footpaths still: in order to make two strips footpath at distinguishable range unit e _kGoing out now of the synthetic correlation peak in interior position can adopt several different methods that two strips are directly put into distinguishable range unit e _kIn: 1) at distinguishable range unit e _kIn put into two strips footpath randomly according to even distribution or normal distribution or other distribution forms, perhaps two strips footpath is placed on distinguishable range unit e respectively _kTwo ends; 2) distinguishable range unit e _kTwo parts before and after being divided into, as dividing with the dotted line in the middle of the son footpath 404,405 among Fig. 4, in each part of front and back, put into strip footpath randomly according to even distribution or normal distribution or other distribution forms respectively, such as: first half is put into son footpath 404, latter half is put into son footpath 405, perhaps e is put in two strips footpath respectively _kCertain fixed position in the two parts of front and back.After putting into son footpath according to the method described above, be exactly distinguishable range unit e by the position of the coefficient correlation peak in son footpath _kGoing out now of internal diameter.

Step 304-2: the generation of the due in the footpath under the accurate LOS channel, be that example describes with two footpaths also: the production method that goes out now in accurate LOS channel footpath and NLOS the channel difference of the production method that goes out now in footpath down are: the production method in first footpath is different, and the production method in other each footpath is identical with the NLOS channel.The accurate LOS channel production method in first footpath down is: a) in diffraction time delay error end, and promptly corresponding first distinguishable range unit e ₁The position of starting point place strip footpath as first footpath, as among Fig. 4 at e ₁Starting point, son footpath 402 is placed as first footpath in the position of the end point of just corresponding diffraction error, first the distinguishable range unit e that directly occupies at head ₁Other interior positions are placed other son footpath randomly, as son footpath 403; B) on the amplitude in son footpath, guarantee to be placed on first distinguishable range unit e ₁Son footpath on the original position, such as the amplitude in son footpath 402 greater than this distinguishable range unit e ₁Other interior son footpath is as son footpath 403.

For the power fading in the generation footpath of being carried in the step 203, the present invention is the method that adopts subwave stack of the prior art, realizes the description of the power fading characteristic of diameter.This method is made up of three basic steps as shown in Figure 5:

Step 501: the amplitude of determination portion partial wave.

The amplitude A of subwave _{I, j}～| N (0, σ _a) |, i wherein, j represent j the subwave in i footpath; N (0, σ _a) be the Gaussian random variable that an average is 0, standard deviation is:

$j=\mathrm{0,1},......,N_w-1,{\mathrm{\σ}}_n=\sqrt{\frac{p_i}{N_w}(1-\sqrt{1-\frac{1}{m_i}})}$

Wherein, p _iIt is the relative power in i footpath; Nw is every subwave number that the footpath is contained, gets 100 usually; m _iIt is the Nakagami decline parameter in i footpath.

Step 502: the phase place of determination portion partial wave.

The phase place of subwave comprises three parts: 1) initial phase φ _{I, j}2) the phase change Δ φ of motion of mobile terminals introducing _{I, j}3) signal of the different antennae of same base station arrives the phase difference Ψ of portable terminal _{I, j}Here, portable terminal can be a travelling carriage.

Here, the initial phase φ of subwave _{I, j}, definite according between [π, π], evenly distributing; Calculate the phase change that causes signal owing to the motion of travelling carriage, as shown in Equation (10), the motion of travelling carriage to the influence of subwave phase place is:

$\mathrm{\Δ}{\mathrm{\φ}}_{\mathrm{ij}}=2\mathrm{\π}\·f_d\·\mathrm{\Δt}=2\mathrm{\π}\·\frac{v}{\mathrm{\λ}}\cos \left(P{a}_{\mathrm{ij}}\right)\·\mathrm{\Δt}=2\mathrm{\π}\·\frac{x}{\mathrm{\λ}}\·\cos \left(P{a}_{\mathrm{ij}}\right)---\left(10\right)$

Wherein, i, j represent j the subwave in i footpath, f _dBe the pairing Doppler frequency shift of subwave, v is the translational speed of travelling carriage, and λ=0.15 meter is the wavelength of radio-frequency carrier, Pa _{I, j}Be the angle that subwave arrives travelling carriage, x is measuring the travelling carriage displacement that the initial moment is a reference origin, and unit be meter.

The calculating that arrives the phase difference of travelling carriage for different antennae signal under the same base station is like this: in the multiaerial system of base station, with some antennas wherein as initial point (0,0), promptly with this antenna as the reference antenna, the polar coordinates of all the other k antennas are (r _k, Θ _k), so, the difference that the signal of k antenna and reference antenna signal arrive the phase place of travelling carriage is:

$\mathrm{\Δ}{\mathrm{\ψ}}_{i,j}=\frac{2\mathrm{\π}}{\mathrm{\λ}}\·r_k\·\cos ({\mathrm{\Θ}}_k-{\mathrm{\θ}}_i)$

Wherein, i, j represent j the subwave in i footpath, the 1st, the wavelength of radio-frequency carrier, θ _iBe the angle that i directly leaves antenna for base station, the angle that each subwave leaves antenna for base station in the i footpath all equals θ _i

Step 503: carry out the subwave stack, produce the instantaneous amplitude in footpath with required fading characteristic.

With N _wIndividual subwave is superimposed to constitute and obeys the footpath that Nakagami-m distributes, and wherein the I road amplitude in i footpath is:

$\underset{j=0}{\overset{N_w-1}{\mathrm{\Σ}}}{A}_{i,j}\cos ({\mathrm{\φ}}_{i,j}+\mathrm{\Δ}{\mathrm{\φ}}_{i,j}+{\mathrm{\Δ\ψ}}_{i,j})$

The Q road amplitude in i footpath is:

$\underset{j=0}{\overset{N_w-1}{\mathrm{\Σ}}}{A}_{i,j}\sin ({\mathrm{\φ}}_{i,j}+{\mathrm{\Δ\φ}}_{i,j}+{\mathrm{\Δ\ψ}}_{i,j})$

Here, A _{I, j}, φ _{I, j}Be respectively the amplitude and the initial phase of j the subwave in i footpath.

In a word, the above is preferred embodiment of the present invention only, is not to be used to limit protection scope of the present invention.

Claims (9)

1, a kind of production method of power time delay distribution is characterized in that this method may further comprise the steps:

A. with minimum range resolution as distinguishable range unit, power time delay distribution number and gross power time delay distribution number according to maximum additional time delay calculate the appearance ratio that power time delay distributes, and further obtain distinguishable range unit set, determine going out now of this set internal diameter then;

B. going out now of distinguishable range unit set that is obtained according to step a and footpath produces in this set every and power directly occurs;

C. the power in the footpath that obtains according to step b obtains the power fading in footpath.

2, method according to claim 1 is characterized in that, step a further comprises:

A1. according to the power time delay distribution number and the gross power time delay distribution number of the maximum additional time delay of difference, determine the appearance ratio R (p of the power time delay distribution of Different Diameter probability of occurrence Pn _n);

A2. with the possible value space of Pn as sample space, the resulting ratio R (p that occurs of step a1 _n) as the probability of occurrence of Pn, determine to need to produce the Pn of certain power time delay distribution;

A3. with the determined Pn of step a2 as probability of happening, carry out at least one heavy Bei Nuli test, will the distinguishable range unit e of the Bei Nuli test number (TN) k correspondence of incident takes place at every turn _kForm a distinguishable range unit set as element, and the element number that will gather is as the number in footpath on the current power time delay distribution; Wherein the number of times of Bei Nuli test is the number of the distinguishable range unit of current maximum additional time delay correspondence;

A4. determining step a3 generates going out now of set internal diameter.

3, method according to claim 2 is characterized in that, the appearance ratio R (P that the power time delay described in the step a1 distributes _n) be: maximum additional time delay τ _{Max_n}Power time delay distribution number N _nDivided by total power time delay distribution number N.

4, method according to claim 2, it is characterized in that, under non-visible channel, further comprise the now that goes out of determining the footpath described in the step a4: at least two strips are directly put into current distinguishable range unit, directly obtain going out now of current distinguishable range unit internal diameter in the position of the correlation peak of actings in conjunction generation according to all sons.

5, method according to claim 2, it is characterized in that, under accurate non-visible channel, determine going out now of footpath described in the step a4: place strip footpath as first footpath in diffraction time delay error end, position in the first distinguishable range unit that head directly occupies except that placing first footpath is put into the son footpath beyond the first footpath at random, and the amplitude maximum in first footpath; Directly obtain going out now of current distinguishable range unit internal diameter in the position of the correlation peak of actings in conjunction generation according to all sons.

6, method according to claim 4 is characterized in that, describedly son is directly put into current distinguishable range unit is: with all the son footpaths that will put at distinguishable range unit e _kIn put at random according to even distribution or normal distribution form.

7, method according to claim 4 is characterized in that, describedly son is directly put into current distinguishable range unit is: with distinguishable range unit e _kBe divided into one with top by the number that will put into the footpath, put into a footpath at random according to even distribution or normal distribution form in every part; Or, with distinguishable range unit e _kBe divided into one with top by the number that will put into the footpath, more every footpath be positioned over the fixed position of every part respectively.

8, method according to claim 1 is characterized in that, the power A in each footpath in the distinguishable range unit set described in the step b _kIn (0.5-1.5), produce according to even distribution; Or according to $A_k=V_k+0.1*V_k{e}^{-\frac{6t_k}{{\mathrm{\τ}}_{\max \_k}}}$ Produce; Or according to $A_k=V_k{e}^{-\frac{6t_k}{{\mathrm{\τ}}_{\max \_k}}}$ Produce; V wherein _kBe the stochastic variable that in (0.5-1.5), produces, t according to even distribution _kBe specifically going out now of distinguishable range unit set internal diameter.

9, method according to claim 1 is characterized in that, obtains the power fading in footpath described in the step c and adopts the mode of subwave stack to realize.

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