CN102223192B - Method and device for constructing composite small-scale radio channel model of high-speed rail - Google Patents

Abstract

The invention provides a method and device for constructing a composite small-scale radio channel model of a high-speed rail, relating to the radio communication field. The method comprises the following steps of: 1, constructing typical scene sub-channels according to various types of scenes experienced by the high-speed rail; 2, according to the high-speed rail to be tested, selecting corresponding composite small-scale sub-channel types and the typical scene sub-channels; 3, sequencing all selected typical scene sub-channels according to requirements; confirming the duration time of each typical scene sub-channel; and 4, combining the typical scene sub-channel types according to the determined arrangement way and the relative duration time; and obtaining the composite small-scale radio channel model of the high-speed rail. The device comprises a sub-channel constructor, a type selector, a sequencing and time confirmer and a combiner. By means of the method and the device disclosed by the invention, the required complete comprehensive radio channel model of the high-speed rail can be obtained, the radio channel of the high-speed rail can be depicted accurately and comprehensively, and the accuracy for test and simulation can be improved.

Description

The method and apparatus that the compound small scale wireless channel model of a kind of high-speed railway builds

Technical field

The present invention relates to wireless communication field, particularly a kind of method and apparatus that builds the compound small scale wireless channel model structure of high-speed railway.

Background technology

In recent years, the progress of China Railway High-speed (hereinafter to be referred as " high ferro ") complete set technology is highly visible, and high ferro has become national significant achievement.China is the country that Development of High Speed Railway is the fastest in the world, systems technology is the most complete, integration capability is the strongest, operation mileage is the longest, the speed of service is the highest, building scale is maximum at present.Along with the development of high-speed railway, the communication between high-speed iron bus ground becomes a hot issue of academia's industrial circle research gradually.The broadband data service that the passenger of take is main body and also become gradually the main business of high ferro broadband wireless access towards the detection transfer of data in transit of security of operation, high ferro broadband access requires to support existing 2G, 3G mobile communication system, can smooth upgrade to future communications system, and requirement can be supported the non-security data service of railway transportation.Therefore, the wireless access wide band technology under current high ferro scene is one of matter of utmost importance of high-speed railway complete set technology.

Channel is the basis of Communication System Design, and accurately cognition wireless channel is the precondition of design of communications system, and it provides true reference for the design of communication system prototype and system, link level simulation, so high ferro wireless channel becomes the matter of utmost importance of research thereupon.In Radio Transmission Technology research, design and normalization period, need to carry out Performance Evaluation to various candidate schemes.And at the initial stage of evaluation process, generally adopt the method for Computer Simulation, and short because it has the construction cycle, adjust flexibly the advantage such as cost is low.Aspect the standardization of wireless technology, for different candidate technologies being had to a unified Evaluation Platform, generally can adopt unified standardization assessment channel model simultaneously.Whether the accuracy of the channel model using evaluation stage has directly determined reliability, the accuracy of simulation result.Therefore at high ferro broadband wireless, count in system evaluation process, what first will solve is the standardization effort of channel model.In the deployment of practical wireless communication systems, needs basis on the spot wireless propagation environment is carried out the network planning, capacity optimization, the work such as blind area covering.Channel model (particularly path loss and shadow fading model) can make network design, Optimization Work more accurately and be effective accurately, thereby promotes the Performance And Reliability of wireless network.

When bullet train passes through base station, there is the quick change point of Doppler, from an extreme frequency deviation, to another extreme frequency deviation, change rapidly.If under tunnel scene, track is nearer to the distance of base station, and its Doppler switches and changes will be more violent, the sharply variation of now system transmission experience Doppler frequency deviation.

Yet, existing channel simulator (Channel Emulator) or channel simulation model, model is single model of place, as Plain, mountain area, city etc., and single form scene channel model is difficult to accurately portray high ferro wireless channel model, poor practicability.

Summary of the invention

Technical problem to be solved by this invention is to provide the method and apparatus that the compound small scale wireless channel model of a kind of high-speed railway builds, and obtains the compound small scale wireless channel model of high-speed railway accurately.

In order to address the above problem, the invention discloses the method that the compound small scale wireless channel model of a kind of high-speed railway builds, comprising:

Step 101, the various scenes of pressing high-speed railway experience build typical scene subchannels;

Step 102, according to high-speed railway to be tested, select corresponding compound small scale sub-channel types and typical scene subchannel;

Step 103, selected all typical scene subchannels are arranged by demand, confirmed the duration of each typical scene subchannel;

Step 104, by described to determine that the typical scene sub-channel types of arrangement mode and corresponding duration combines, obtain the compound small scale wireless channel model of high ferro.

Preferably, the method for described structure typical scene subchannel comprises that employing high-speed railway actual scene measurement model parameter builds or adopt classical model to build.

Preferably, described classical model comprises COST207 classical model, COST259 classical model or SUI classical model.

Preferably, described sub-channel types comprises simple high-speed railway type, complicated high-speed railway type and free type.

Preferably, described arrangement mode comprises classical pattern of rows and columns, random alignment pattern and free pattern of rows and columns.

Preferably, described subchannel comprises tapped delay line model or bunch delay line model.

Preferably, described tapped delay line model or a bunch delay line model comprise that channel time postpones territory, channel space territory and channel Doppler territory.

The invention also discloses the device that the compound small scale wireless channel model of a kind of high-speed railway builds, comprising:

Subchannel builds device, for setting up typical scene subchannel by the various scenes of high-speed railway experience;

Type selecting device, for according to high-speed railway circuit type selecting corresponding typical fields scape subchannel to be tested;

Sequence and time validator, for selected all typical scene subchannels are arranged by demand, confirm the duration of each typical scene subchannel;

Combiner, for by described to determine that the typical scene sub-channel types of arrangement mode and corresponding duration combines, and obtains high ferro wireless channel model.

Compared with prior art, the present invention has the following advantages:

The present invention is compound by ergodic or selectivity are carried out high-speed railway typical scene subchannel, obtains needed complete comprehensive high-speed railway wireless channel model, accurately comprehensively portrays high ferro wireless channel, the accuracy while improving test and emulation.

Accompanying drawing explanation

Fig. 1 is the flow chart of the method for the compound small scale wireless channel model structure of a kind of high-speed railway of the present invention;

Fig. 2 is the method method flow diagram that the compound small scale wireless channel model of the preferred a kind of high-speed railway of the present invention builds;

Fig. 3 is the installation drawing that the compound small scale wireless channel model of a kind of high-speed railway of the present invention builds;

Embodiment

For above-mentioned purpose of the present invention, feature and advantage can be become apparent more, below in conjunction with the drawings and specific embodiments, the present invention is further detailed explanation.

With reference to Fig. 1, show the flow chart of the method for the compound small scale wireless channel model structure of a kind of high-speed railway of the present invention.

Step 101, the various scenes of pressing high-speed railway experience build typical scene subchannels.

Actual high speed railway may, through scenes such as Plain, overpass, mountain area, tunnel, U-shaped groove, hills, station, city, waters, be divided into high-speed railway wireless channel by these scenes the typical scene subchannels such as Plain, overpass, mountain area, tunnel, U-shaped groove, hills, station, city, waters so.

Wherein, the construction method of typical scene subchannel, can adopt high ferro actual scene measurement model parameter to build or adopt classical model to build,, when having high ferro actual scene measurement model parameter, by this actual scene measurement model parameter, building typical scene subchannel; When high ferro actual scene measurement model parameter, the classical models such as available COST207, COST259, SUI build.Wherein, the information of typical scene subchannel model comprises that channel time postpones the information of territory, Doppler territory, spatial domain.

Wherein typical scene subchannel comprises tapped delay line (Tapped Delay Line-TDL) or bunch delay line model (Clustered Delay Line-CDL), and this model comprises that channel time postpones the information of territory, Doppler (Doppler) territory, spatial domain.

For example that channel tap delay line model is simplified in the rural area that adopts COST 207 to set up below:

Wherein the information in time delay territory comprises path relative time delay etc., and the letter of spatial domain comprises path gain etc., and the information in Doppler territory comprises Doppler's power spectrum etc.

Wherein, the path K factor can be determined with the following method, but be not limited to this.Wherein μ s is microsecond, is decibel.

The probability density function of Rice is:

$P\left(r\right)=\frac{r}{{\mathrm{\σ}}^2}\·\exp (-\frac{r^2+s^2}{2{\mathrm{\σ}}^2})\·I_0(-\frac{r\·s}{{\mathrm{\σ}}^2})$

According to the expression formula of the Order Moments of this distribution of Lay:

${\mathrm{\μ}}_n=E\left[r^n\right]={\left(2{\mathrm{\σ}}^2\right)}^{\frac{n}{2}}\exp (-K)\mathrm{\Γ}(1+\frac{n}{2})F_1(1+\frac{n}{2};1;K)$

Wherein, Γ () is gamma function, F ₁() is confluent hypergeometric function, and this square even square has enclosed to be expressed as:

μ ₂＝E[r ²]＝s ²+2σ ²＝2σ ²(K+1)，μ _４＝E[r ⁴]＝8σ ⁴+8σ ²s ²+s ⁴

$\frac{{\mathrm{\μ}}_2^2}{{\mathrm{\μ}}_4^2}=\frac{{(1+K)}^2}{K^2+4K+2}$

The equation left side can be by measuring, and the right can be by calculating as follows containing K expression formula:

$K=\frac{-2{\mathrm{\μ}}_2^2+{\mathrm{\μ}}_4-{\mathrm{\μ}}_2\sqrt{{\mathrm{\μ}}_2^2-{\mathrm{\μ}}_4}}{{\mathrm{\μ}}_2^2-{\mathrm{\μ}}_4}$

Time delay field parameter can be determined by the following method:

First, receiver receives the signal under high ferro scene, carries out channel estimating obtain channel impulse response information in this locality; Then channel impulse response information is added up, statistical method can adopt bunch partition method based on the time interval or the power partition method based on power fading.

Doppler territory can be determined by the following method:

First set CIR (Impulse response of channel, channel impulse response) the make an uproar end and threshold value, then select the impulse response h (t) of the first footpath signal, then window and add up the correlation function of some sample impulse responses, last pair correlation function carries out Fourier and changes the Doppler power spectrum that obtains the first footpath.

Following for simplifying channel tap delay line model in the mountain area that adopts COST 207 to set up:

Rural WinnerII bunch of delay line model below:

Wherein: AoA represents (Angle of Arrival, arrive angle), AoD represents (Angle of Departure, leave angle), ASD represents (Azimuth Spread at Departure, set out and propagate orientation), ASA represents (Azimuth Spread at Arrival arrives and propagates orientation), and XPR represents (Cross-Polarisation power Ratio, cross polarization power ratio), Ray power represents radiation power, and Cluster represents bunch, and delay represents to postpone, power represents power, and ns represents nanosecond.

Wherein, a bunch delay line model can build with the following method:

Understanding for cluster is as follows: some rays form a cluster, is referred to as bunch.Cluster and ray are the relation in He Zi footpath, footpath in fact.Cluster can be regarded as upper differentiable propagation footpath, space (time and angle).Step comprises:

Step s1 generates time delay;

Step s2 generates cluster power;

Step s3 generates weighting vector and leaves wave angle degree;

The random pair in step s4 footpath;

Step s5 generates the cross polarization power ratio under sub-footpath;

Step s6 generates random initial phase to the every strip footpath in each cluster;

Step s7 generates reception antenna u, the channel coefficients between transmitting antenna s on n bar cluster;

Two cluster that step s8 is the strongest to power, are divided into 3 submanifolds.

Step 102, according to high-speed railway to be tested, select corresponding compound small scale sub-channel types and subchannel;

After step 101 has been set up each typical scene subchannel, according to tape test high-speed railway, select corresponding compound small scale sub-channel types and typical scene subchannel, according to different tests and emulation demand, (be different high ferro circuits, scene is different), determine above-mentioned typical scene sub-channels.

Wherein compound small scale sub-channel types comprises naive model, and complex model and free model, such as naive model (as Beijing-Tianjin inter-city high ferro), can be selected overpass, Plain typical scene subchannel; Complicated high ferro circuit (as Zheng Xi high ferro) model, can select Plain, overpass, mountain area, tunnel, U-shaped groove, hills, station, city, waters typical subchannel model completely, or free model according to demand, such as working as, need to use tunnel, hills, waters, these typical scene subchannels of mountain area, and naive model and complex model do not comprise again, so just can oneself selected corresponding subchannel form free model.

Step 103, selected all typical scene subchannels are arranged by demand, confirmed the duration of each typical scene subchannel;

Channel arrangement mode, can be according to test and emulation Location of requirement (be different high ferro circuits, scene is different).Wherein arrangement mode comprises containing classical pattern of rows and columns, random alignment pattern, free pattern of rows and columns.The acknowledged arrangement mode of classical mode for having existed, for example city-overpass-mountain area-tunnel-overpass-city, or city-overpass-city; Random alignment pattern when selected compound type and typical scene subchannel from step 103 after, arranges subchannel at random; Free pattern of rows and columns has been selected after compound small scale type and subchannel, by demand manual alignment typical scene subchannel.

Simulation time can be definite by concrete test request, and as emulation Beijing-Tianjin inter-city circuit, the testing time can be set to 30 minutes, the systematic function in the whole measuring process of emulation, and the duration of each typical scene subchannel is also determined by concrete test request.In test or simulation process, transmit and experience continuously respectively scene change, duration of each typical scene subchannel and equal total simulation time, the duration of every subchannel, substantially the time and on true circuit is consistent, and generally, in test, can add up every kind of duration that scene is general, when subchannel is arranged, just can be as foundation.In addition, determine the duration of every sub-channels, change parameter (information of time delay territory, Doppler territory, spatial domain) equally according to test and emulation Location of requirement.

Step 104, by described to determine that the typical scene sub-channel types of arrangement mode and corresponding duration combines, obtain the compound small scale wireless channel model of high ferro.

Having determined the arrangement mode of sub-channel types and selected complete typical scene subchannel and after the duration, having combined, finally obtain the compound small scale wireless channel model of high ferro.

With reference to Fig. 2, show the method method flow diagram that the compound small scale wireless channel model of the preferred a kind of high-speed railway of the present invention builds.

Wherein step 101 has comprised by adopting high ferro actual scene measurement model parameter to build or adopt classical model to build typical scene subchannel.

Step 102 has comprised according to high-speed railway to be tested selects naive model, complex model or free model.

Step 103 comprises:

Step 1, model and corresponding typical scene subchannel after first step 102 having been selected select one of classical pattern of rows and columns, random alignment pattern, free pattern of rows and columns to arrange.

Step 2, by duration and the total testing time of a requirement validation typical scene subchannel.

Step 104, to determine that the typical scene sub-channel types of arrangement mode and corresponding duration combines, obtains the compound small scale wireless channel model of high ferro by described.

In reality, this composite model only relates to multipath fading feature.

The present invention also provides a kind of high-speed railway device that compound small scale wireless channel model builds, and comprising:

Subchannel builds device, for setting up typical scene subchannel by the various scenes of high-speed railway experience;

Type selecting device, for according to high-speed railway circuit type selecting corresponding typical fields scape subchannel to be tested;

Sequence and time validator, for selected all typical scene subchannels are arranged by demand, confirm the duration of each typical scene subchannel;

Combiner, for by described to determine that the typical scene sub-channel types of arrangement mode and corresponding duration combines, and obtains high ferro wireless channel model.

By above-mentioned elaboration, according to the compound small scale channel model of high ferro of the present invention construction method, can construct the channel model under tallying with the actual situation, whole channel model has good practicality, the many scene variation characteristics of high ferro have truly been portrayed, test on this basis and emulation, the existing and new modulation techniques of Improvement and perfection, communication protocol and encoding scheme, improve the quality of high ferro broadband wireless access.

Each embodiment in this specification all adopts the mode of going forward one by one to describe, and each embodiment stresses is the difference with other embodiment, between each embodiment identical similar part mutually referring to.For system embodiment, because it is substantially similar to embodiment of the method, so description is fairly simple, relevant part is referring to the part explanation of embodiment of the method.

Above a kind of method and apparatus that builds the compound small scale wireless channel model structure of high-speed railway provided by the present invention is described in detail, applied specific case herein principle of the present invention and execution mode are set forth, the explanation of above embodiment is just for helping to understand method of the present invention and core concept thereof; , for one of ordinary skill in the art, according to thought of the present invention, all will change in specific embodiments and applications, in sum, this description should not be construed as limitation of the present invention meanwhile.

Claims (8)

1. the method that the compound small scale wireless channel model of high-speed railway builds, is characterized in that, comprising:

Step 101, the various scenes of pressing high-speed railway experience build typical scene subchannels;

Step 102, according to high-speed railway to be tested, select corresponding compound small scale sub-channel types and typical scene subchannel; Wherein compound small scale sub-channel types comprises naive model, complex model and free model;

Step 103, selected all typical scene subchannels are arranged by demand, confirmed the duration of each typical scene subchannel;

Step 103 comprises:

Step 1, model and corresponding typical scene subchannel after first step 102 having been selected select one of classical pattern of rows and columns, random alignment pattern, free pattern of rows and columns to arrange;

Step 2, by duration and the total testing time of a requirement validation typical scene subchannel; Duration of each typical scene subchannel and equal total simulation time wherein;

Step 104, by determine that the typical scene sub-channel types of arrangement mode and corresponding duration combines, obtain the compound small scale wireless channel model of high ferro.

2. the method that the compound small scale wireless channel model of high-speed railway builds as claimed in claim 1, is characterized in that:

The method of described structure typical scene subchannel comprises that employing high-speed railway actual scene measurement model parameter builds or adopt classical model to build.

3. the method that the compound small scale wireless channel model of high-speed railway builds as claimed in claim 2, is characterized in that:

Described classical model comprises COST207 classical model, COST259 classical model or SUI classical model.

4. the method that the compound small scale wireless channel model of high-speed railway builds as claimed in claim 1, is characterized in that:

Described sub-channel types comprises simple high-speed railway type, complicated high-speed railway type and free type.

5. the method that the compound small scale wireless channel model of high-speed railway builds as claimed in claim 1, is characterized in that:

Described arrangement mode comprises classical pattern of rows and columns, random alignment pattern and free pattern of rows and columns.

6. the method that the compound small scale wireless channel model of high-speed railway builds as claimed in claim 1, is characterized in that:

Described subchannel comprises tapped delay line model or bunch delay line model.

7. the method that the compound small scale wireless channel model of high-speed railway builds as claimed in claim 6, is characterized in that:

Described tapped delay line model or a bunch delay line model comprise that channel time postpones territory, channel space territory and channel Doppler territory.

8. the device that the compound small scale wireless channel model of high-speed railway builds, is characterized in that, comprising:

Subchannel builds device, for setting up typical scene subchannel by the various scenes of high-speed railway experience;

Type selecting device, for according to high-speed railway circuit type selecting corresponding typical fields scape subchannel to be tested;

Sequence and time validator, for selected all typical scene subchannels are arranged by demand, confirm the duration of each typical scene subchannel;

Combiner, for by described to determine that the typical scene sub-channel types of arrangement mode and corresponding duration combines, and obtains high ferro wireless channel model.

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