CN105530703A - GSM-R interference source positioning method based on wave arrival direction estimate value - Google Patents

Abstract

The invention belongs to the railway radio communication net interference source positioning technology and the array signal processing technology field, and relates to a GSM-R interference source positioning method based on a wave arrival direction estimate value. The GSM-R interference source positioning method comprises steps of adopting a GSM-R base station reception antenna to perform DOA estimation on an interference signal incoming wave direction of the interference signal, performing space diversity on the GSM-R base station to construct two groups of antenna arrays, obtaining a DOA estimation result of the interference signal, respectively establishing a linear equation of the connection line between the interference source and two GSM-R base stations to obtain the intersection point of the two straight lines; and the intersection is the position of the interference source. The beneficial effects are that the invention does not need to receive signal frequency spectrum data and is portable; the invention does not need network management system data, the cellular district planning data and the road measurement data and thus is independent; the invention does not need to use the directional antenna to perform step-by-step positioning and is fast; and the invention does not need obtain the environment path loss model in advance and is more flexible.

Description

A kind of GSM-R interference source localization method based on Mutual coupling value

Technical field

The invention belongs to GSM-R (GlobalSystemforMobileCommunications-Railway) interference source location technology and array signal process technique field, particularly about the GSM-R interference source localization method that one is estimated based on interference signal arrival bearing DOA (directionofarrival).

Background technology

GSM-R is a kind of is specially the comprehensive private wireless communication system that railway communication designs, by International Union of Railways (UIC) and European Telecommunication Standard research institute (ETSI) by European railway wireless communication of new generation is researched and developed.GSM-R, based on GSM technology, in conjunction with the demand of railway communication, adds the related services such as multipriority, urgent call, group calling, broadcast & call.GSM-R system is the development trend of China's Railway Communications, and it can realize the various mobile message collection of resources of railway, transmission, for modern railway dispatching, commander, control provide communications platform, improves the running efficiency of railway simultaneously, reduces operating cost.2003, the Ministry of Railways selected the technical system of GSM-R as China railways following integrated digital scheduling net.The introducing of GSM-R system facilitates the development of railway construction in China, accelerates the paces of China railways informatization, improves the competitiveness of China railways, for the economy of country and scientific and technological strength contribute to important strength.

GSM-R frequency band operates mainly within the scope of 885-889/930-934MHz, altogether 4MHz bandwidth, and this frequency range is exclusively enjoyed by GSM-R system.But universal due to current electronic equipment, the electromagnetic environment in life becomes and becomes increasingly complex, due to the shared frequency range of two systems or frequency range close, make the electromagnetic interference between system also become unavoidable.For the electromagnetic environment of relative complex, plurality of wireless networks is had to form, comprise mobile communication operation system, PMR private mobile radio equipment and call/broadcast system, i.e. civilian mobile system, group system and broadcast system, even also have some uncommitted illegal wireless networks, the antenna of these heterogeneous networks sends the wireless signal of various different frequency, different amplitude, unlike signal amount, is therefore easy in space cause interfering with each other between network.

At present, China railways lay along the line various channel, area authorization or undelegated base station and antenna.Although Chinese relevant department defines GSM-R system exclusive 4M bandwidth along the railway, but all the other signals as movement, UNICOM, telecommunications and radio station launch likely cause adjacent frequency interference and the Intermodulation Interference of GSM-R system, and illegal unauthorized obtains the co-channel interference that base station or antenna cause.These wireless interference signals all can affect normal reception and the transmitting of GSM-R, the problems such as call drop, speech quality are poor, channel congestion are brought to the mobile communication of base station coverage area, thus cause the work efficiency drop of railway operation, even give the safe operation of railway, the development of the life security of passenger and country brings secret worry.Therefore, need effective GSM-R interference source localization method badly, timely exclusive PCR source on the impact of GSM-R communication system, to ensure the fail safe of railway transportation.

Present stage, the method that interference source positions mainly is comprised: utilize spectrum analysis to position the outer interference of net; Network management system data, cellular cell layout data and test data is utilized to position interference source; Directional antenna is adopted to carry out Step wise approximation location; Electromagnetic wave power propagation model and path loss model is utilized to position interference source.Array Signal Processing is not also adopted to position interference source the method that the arrival bearing of interference signal carries out DOA estimation at present.

Summary of the invention

The object of the invention is the shortcoming and defect overcoming prior art, propose a kind of use array signal process technique, quick position is carried out to GSM-R interference source.GSM-R system is mainly used in Line for Passenger Transportation or high-speed line, and many places are in rural open ground, and electromagnetic wave is based on straightline propagation, and multipath effect is not obvious, and the arrival bearing of interference signal therefore can be utilized to position interference source.In these areas, GSM-R system adopts the antenna of space diversity, and the parallel placement in antenna left and right, can regard the even linear array aerial array of horizontal positioned as.

Technical scheme of the present invention is: a kind of GSM-R interference source localization method based on Mutual coupling value, is characterized in that, comprise the following steps:

A. adopt GSM-R base station receive antenna to carry out DOA estimation to interference signal arrival bearing, concrete grammar is: carry out space diversity to GSM-R antenna for base station, builds two groups of aerial arrays, obtains the DOA estimated result to interference signal;

B. according to the DOA estimated result obtained in step a, set up the linear equation of interference source and two GSM-R base station receive antenna lines respectively, obtain the intersection point of these two straight lines, this intersection point is the position of interference source.

The technical scheme that the present invention is total, main employing array signal process technique, use multi-antenna array to carry out DOA estimation to the arrival bearing of interference source signal, and according to the estimated result of two groups of aerial arrays to the arrival bearing of same interference signal, interference source is positioned.

Further, step a specifically comprises the following steps:

A1. form even linear array with the antenna of space diversity, each antenna represents an array element;

A2. even linear array is carried out front/rear to space smoothing, construct multiple front/rear to smooth uniform linear array subarray;

A3. set up each front/rear to smooth uniform linear array sub-array receive signal model, and calculate each front/rear Received signal strength spatial correlation matrix to smooth uniform linear array subarray;

A4. each front/rear Received signal strength spatial correlation matrix to smooth uniform linear array subarray is averaging, obtains the two-way space smoothing correlation matrix of even linear array;

A5. according to the two-way space smoothing correlation matrix obtained, the DOA estimated result of MUSIC algorithm acquisition to interference signal is adopted.

The present invention can with beneficial effect be that the present invention does not need Received signal strength frequency spectrum data, more convenient; Do not need the Correlative plan data such as network management system data, cellular cell layout data and drive test data, more independent; The present invention progressively locates without the need to using directional antenna, faster; The present invention does not need the path loss model obtaining environment in advance, more flexibly.

Accompanying drawing explanation

Fig. 1 is method flow diagram of the present invention;

Fig. 2 is the even linear array aerial array schematic diagram that the GSM-R base station spatial diversity antennas of the embodiment of the present invention is formed;

Fig. 3 is the GSM-R interference source location schematic diagram of the embodiment of the present invention;

Fig. 4 is the level and smooth subarray schematic diagram of even linear array forward direction of the employing of the embodiment of the present invention;

Fig. 5 is the backward level and smooth subarray schematic diagram of the even linear array of the employing of the embodiment of the present invention;

Fig. 6 is that embodiment of the present invention GSM-R base station 1 is to the DOA estimated result expecting GSM-R signal and interference signal;

Fig. 7 is that embodiment of the present invention GSM-R base station 2 is to the DOA estimated result expecting GSM-R signal and interference signal.

Embodiment

Below in conjunction with drawings and Examples, the present invention is described in detail

As shown in Figure 1, GSM-R interference source localization method based on Mutual coupling value of the present invention, primary solutions is: first consider the situation that may be concerned with between homogenous frequency signal, adopt the GSM-R base station receive antenna of space diversity, use even linear array space smoothing algorithm to carry out DOA estimation to the arrival bearing of interference signal; Then according to the geometric position of two groups of aerial arrays to the estimated result of the arrival bearing of same interference signal and two groups of aerial arrays, draw two crossing straight lines, the intersection point of two straight lines is the position of interference source.

Embodiment

As shown in Figure 2, be described in detail in same level so that 10 antenna left and right of GSM-R base station spatial diversity antennas are evenly distributed.

Because Chinese Railway GSM-R system works is in 885-889/930-934MHz band limits, so choose 900MHz as typical frequencies to arrange antenna spacing, antenna spacing is set to (0.5 × 3 × 10 ⁸)/(900 × 10 ⁶)=0.15m.Array element distance, much smaller than the distance between array element and interference source, can think that interference signal arrives the incidence angle of each array element identical.The angle of signal incident direction and even linear array normal direction is θ, the θ ∈ (0 °, 90 °) when signal injects even linear array on the left of normal, the θ ∈ (-90 °, 0 °) when signal injects even linear array on the right side of normal.

As shown in Figure 3, the spatial diversity antennas of GSM-R base station 1 is positioned at coordinate A (0m, 0m) place, the spatial diversity antennas of GSM-R base station 2 is positioned at coordinate B (100m, 0m) place, expects that GSM-R transmitter is positioned at coordinate O (45m, 5m) place, interference source is positioned at coordinate C (50m, 50m) place.

In experimentation, the position of GSM-R base station 1 and GSM-R base station 2 is known.If expect that GSM-R transmitter site is (X ₁, Y ₁), position of interference source is (X ₂, Y ₂).

Expect that GSM-R signal is θ to the incidence angle of base station 1 ₁, interference signal is θ to the incidence angle of base station 1 ₂.Expect that GSM-R signal to the incidence angle of base station 2 is interference signal to the incidence angle of base station 2 is

As shown in Figure 2, the Received signal strength data of base station 1 even linear array reception antenna are:

$\begin{array}{c}x\left(t\right)={\left[\begin{array}{cccc}{x}_1\left(t\right)& x_2\left(t\right)& \mathrm{...}& x_{10}\left(t\right)\end{array}\right]}^T\\ =As\left(t\right)+n\left(t\right)\end{array}$

Wherein, s (t)=[s ₁(t) s ₂(t)] ^tfor expecting GSM-R signal and interference signal, n (t)=[n ₁(t) n ₃(t) ... n ₁₀(t)] ^tthe array received noise of 10 array elements, noise variance is σ ², A=[a (θ ₁) a (θ ₂)] be array guiding matrix, a (θ _i)=[1e ^{-j β i}e ^{-9j β i}] ^tfor signal s _ithe guiding vector of (t), β _i=2 π dsin θ _i/ λ is signal s _it () arrives the phase difference of two adjacent array elements.

As shown in Figure 4, adopt forward direction space smoothing, use array number M=10 even linear array, structure P sub-array combination (P=6), the array number m=5 of each subarray.

The Received signal strength data of a kth subarray are:

$\begin{array}{c}{x}_k^f\left(t\right)={\left[\begin{array}{cccc}{x}_k\left(t\right)& x_{k+1}\left(t\right)& \mathrm{...}& x_{k+m-1}\left(t\right)\end{array}\right]}^T\\ ={\mathrm{CD}}^{(k-1)}s\left(t\right)+n_k\left(t\right)\end{array}$

Wherein, C=[c (θ ₁) c (θ ₂)] for a kth subarray array guiding matrix, c (θ _i)=[1e ^{-j β i}e ^{-j (k-1) β i}] ^tfor signal s _ithe array guiding vector of a kth subarray of (t), $D=\left[\begin{array}{cc}{e}^{-{\mathrm{j\β}}_1}& 0\\ 0& e^{-{\mathrm{j\β}}_2}\end{array}\right]$ For the phase shift matrix between adjacent subarray, n _k(t)=[n _k(t) n _k+1(t) ... n _k+4(t)] ^tfor the array received noise of a kth subarray.

The received signal vector of a kth subarray spatial correlation matrix be:

$R_{xk}^f=E\left\{x_k^f\left(t\right){\left(x_k^f\right(t\left)\right)}^H\right\}={\mathrm{CD}}^{(k-1)}{R}_s{\left(D^{(k-1)}\right)}^H{C}^H+{\mathrm{\σ}}^{2}I$

Wherein, R _s=E{s (t) s ^h(t) } for interference source transmits spatial correlation matrix, I is unit battle array.

The spatial correlation function of each forward direction space smoothing subarray is averaging, forward direction space smoothing spatial correlation function can be obtained.

$R_x^f\left(\mathrm{\τ}\right)=\frac{1}{P}\underset{k=1}{\overset{P}{\Σ}}{R}_{xk}^f\left(\mathrm{\τ}\right)$

In like manner, as shown in Figure 5, the auto-correlation function matrix by obtaining after backward space smoothing can be obtained

$R_x^b\left(\mathrm{\τ}\right)=\frac{1}{P}\underset{k=1}{\overset{P}{\Σ}}{R}_{xk}^b\left(\mathrm{\τ}\right)$

$R_{xk}^b=E\left\{x_k^b\left(t\right){\left(x_k^b\right(t\left)\right)}^H\right\}={\mathrm{CD}}^{(m+k-2)}{R}_s{\left(D^{(m+k-2)}\right)}^H{C}^H+{\mathrm{\σ}}^{2}I$

Two-way space smoothing algorithm is averaged forward direction level and smooth Cyclic Autocorrelation Function matrix and backward level and smooth Cyclic Autocorrelation Function matrix exactly, and two-way space smoothing Cyclic Autocorrelation Function matrix is:

$R_x\left(\mathrm{\τ}\right)=\frac{1}{2}\left(R_x^f\right(\mathrm{\τ})+R_x^b(\mathrm{\τ}\left)\right)$

To R _x(τ) Eigenvalues Decomposition is carried out, two larger eigenvalue λ ₁, λ ₂characteristic of correspondence vector u ₁, u ₂form signal subspace, three less eigenvalue λ ₃, λ ₄, λ ₅characteristic of correspondence vector u ₃, u ₄, u ₅form noise subspace.Definition matrix:

G＝[u ₃u ₄u ₅]

Because matrix A is sequency spectrum matrix, R _xfor non-singular matrix, can prove:

G ^HA＝G ^H[a(θ ₁)a(θ ₂)]＝0

I.e. G ^ha (θ _i)=0.Therefore can reach a conclusion, when θ is signal arrival bearing, G ^ha (θ)=0.

Use MUSIC Power estimation:

$P_{MUSIC}=\frac{1}{a^H\left(\mathrm{\θ}\right){\mathrm{GG}}^{H}a\left(\mathrm{\θ}\right)},\mathrm{\θ}\∈(-\frac{\mathrm{\π}}{2},\frac{\mathrm{\π}}{2})$

When θ is signal arrival bearing, P _mUSICobtain maximum, by MUSIC spectrum peak search, the arrival bearing of signal can be obtained.

By experiment, the expectation GSM-R signal arrival bearing of GSM-R base station 1 estimation interference signal arrival bearing is as shown in Figure 6.The expectation GSM-R signal arrival bearing that GSM-R base station 2 is estimated is interference signal arrival bearing is as shown in Figure 7.

For interference signal, according to the interference signal arrival bearing that GSM-R base station 1 and GSM-R base station 1 are estimated be the interference signal arrival bearing that position, GSM-R base station 2 and GSM-R base station 2 are estimated is the equation group of the straight line expecting GSM-R signal place can be obtained:

$\left\{\begin{array}{c}tan{\mathrm{\θ}}_{12}=-\frac{X_2}{Y_2}\\ {\mathrm{tan\θ}}_{22}=-\frac{X_2-100}{Y_2}\end{array}\right.$

Solving equation group, can calculate position of interference source (50.026m, 49.991m) respectively.

As can be seen from experimental result, adopt the inventive method, the arrival bearing of the interference signal that can only use GSM-R to detect just can position interference source easily and efficiently.

Claims (2)

1., based on a GSM-R interference source localization method for Mutual coupling value, it is characterized in that, comprise the following steps:

A. adopt GSM-R base station receive antenna to carry out DOA estimation to interference signal arrival bearing, concrete grammar is: carry out space diversity to GSM-R antenna for base station, builds two groups of aerial arrays, obtains the DOA estimated result to interference signal;

B. according to the DOA estimated result obtained in step a, set up the linear equation of interference source and two GSM-R base station receive antenna lines respectively, obtain the intersection point of these two straight lines, this intersection point is the position of interference source.

2. a kind of GSM-R interference source localization method based on Mutual coupling value according to claim 1, it is characterized in that, step a specifically comprises the following steps:

A1. form even linear array with the antenna of space diversity, each antenna represents an array element;

A2. even linear array is carried out front/rear to space smoothing, construct multiple front/rear to smooth uniform linear array subarray;

A3. set up each front/rear to smooth uniform linear array sub-array receive signal model, and calculate each front/rear Received signal strength spatial correlation matrix to smooth uniform linear array subarray;

A4. each front/rear Received signal strength spatial correlation matrix to smooth uniform linear array subarray is averaging, obtains the two-way space smoothing correlation matrix of even linear array;

A5. according to the two-way space smoothing correlation matrix obtained, the DOA estimated result of MUSIC algorithm acquisition to interference signal is adopted.