JP2011047865A - Device and method for antenna evaluation - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an antenna evaluation device and method, capable of generating a correlationship between fading fluctuation that occurs in vertical and horizontal polarized wave components. <P>SOLUTION: The antenna evaluation device 1 includes a time variable factor generating part 10 for generating a pair of correlational time variable factors having correlation with each other, a composite signal generating part 20 for generating a composite signal by multiplying the pair of correlational time variable factors with base band signal, a transmission antenna T for transmitting test radio waves containing composite signal in respective vertical polarized wave component and horizontal polarized wave component to an antenna to be evaluated. The time variable factor generating part 10 provides a correlationship of a correlational amount between vertical polarized wave component and horizontal polarized waved component at a reception end which is determined by a given inter-polarized waves covariance matrix Γ, to the pair of correlational time variable factors. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  Embodiments discussed herein relate to an antenna characteristic evaluation system that evaluates antenna characteristics.

  During antenna design, antenna characteristics are evaluated. When evaluating the characteristics of a multi-antenna, not only the characteristics of a single antenna but also the correlation between antennas is an evaluation index for determining antenna characteristics.

  Inter-antenna correlation affects the performance of antenna characteristics in a fading environment. For this reason, some simulators that perform multi-antenna characteristic evaluation reproduce a fading environment.

  A scatterer comprising a plurality of radiators, a scatterer support for holding the scatterers, and a circuit unit connected to the plurality of radiators, wherein at least the amplitude of each radio wave radiated from the plurality of radiators or An electromagnetic wave environment of the device under test in a multi-wave propagation environment constructed by a scatterer, in which one of the phases is controlled by a circuit unit, and the device under test having at least one antenna as a component is arranged near the center of the scatterer An antenna evaluation apparatus characterized by performing a test has been proposed. This antenna evaluation apparatus controls so that the ratio of the average transmission power of the vertical polarization antenna and the horizontal polarization antenna becomes a desired cross polarization discrimination. By using such a radiator for a scatterer, it is possible to radiate vertically polarized waves and horizontally polarized waves at the same time, and to construct a multi-wave propagation environment closer to the actual environment.

  Also, a plurality of antennas provided around the wireless terminal, a signal source that generates a signal equivalent to a base station, a distributor that distributes the signal generated by the signal source by the number of antennas, and a plurality of antennas radiate There has been proposed a wireless terminal test apparatus including a fading generator that adjusts each output of a distributor so that a radio wave has real-world characteristics in each antenna direction viewed from the wireless terminal. The antenna can radiate two types of polarized waves.

  Further, for simulation in several spatial radio channel models, each propagation channel between the vertical polarization component and horizontal polarization component in the base station apparatus and the vertical polarization component and horizontal polarization component in the mobile station apparatus A polarization covariance matrix, which is a coefficient covariance matrix, has been proposed.

  Further, in order to construct a radio wave environment for evaluating characteristics of a MIMO terminal, a fading emulator has been proposed that generates a fading environment by arranging transmission antennas corresponding to a plurality of scatterers around the terminal.

JP 2005-227213 A JP 11-340930 A

3GPP contribution, “R4-060334”, “LTE Channel Models and simulations” [searched July 13, 2009], Internet (http://www.3gpp.org/ftp/tsg_ran/WG4_Radio/tsgr4_38/Docs/R4 -060334.zip) Yoshio Karasawa, 1 other, "Consideration on Radio Environment Construction Method for MIMO Terminal Characteristics Evaluation", IEICE Technical Report, IEICE, January, 108, 386, AP2008-185 , P. 203-208

  In an actual environment, conversion from a vertically polarized wave component to a horizontally polarized wave component and from a horizontally polarized wave component to a vertically polarized wave component occurs due to the influence of reflection of radio waves on the propagation path. For this reason, a correlation may occur between the fading fluctuation generated in the vertical polarization component and the fading fluctuation generated in the horizontal polarization component. Therefore, when an inter-polarization covariance matrix is given for a certain propagation path model, the correlation between the vertical polarization component and the horizontal polarization component generated corresponding to this inter-polarization covariance matrix can be reproduced. This is a desirable function as a simulator.

  An object of the apparatus and method according to the embodiment is to provide an antenna evaluation apparatus and an antenna evaluation method capable of generating a correlation between fading fluctuations generated in a vertical polarization component and fading fluctuations generated in a horizontal polarization component. To do.

  An antenna evaluation apparatus according to an embodiment combines a time-varying coefficient generating unit that generates a pair of correlated time-varying coefficients that are correlated with each other and a baseband signal by multiplying the correlated time-varying coefficient by a baseband signal. Antenna to be evaluated for a test signal having a composite signal generation unit that generates a signal and a composite signal generated by multiplying a pair of correlation time-varying coefficients by a baseband signal in a vertical polarization component and a horizontal polarization component, respectively And a transmitting antenna for transmitting to. The time-varying coefficient generator is defined by a given inter-polarization covariance matrix that defines the covariance matrix of each propagation channel coefficient between the vertical and horizontal polarization components at the transmission and reception ends of the propagation path model. The correlation of the correlation amount between the vertical polarization component and the horizontal polarization component at the reception end is given to the pair of correlation time-varying coefficients.

  According to the apparatus or method of the present disclosure, in the antenna evaluation apparatus and the antenna evaluation method, between the fading fluctuation generated in the vertical polarization component of the test radio wave transmitted to the antenna to be evaluated and the fading fluctuation generated in the horizontal polarization component, A correlation according to a given inter-polarization covariance matrix can be generated.

It is a block diagram of 1st Example in an antenna evaluation apparatus. It is a figure which shows the structural example of a time-varying coefficient production | generation part. It is a figure which shows the structural example of a synthetic | combination signal production | generation part. (A) is explanatory drawing of the propagation channel coefficient by which the correlation between polarized waves is represented by the inter-polarization covariance matrix (GA), (B) is explanatory drawing of the propagation path model of the electromagnetic wave in an antenna evaluation apparatus. It is a block diagram of 2nd Example in an antenna evaluation apparatus. It is a figure which shows the structural example of the signal processing part shown in FIG. It is a figure which shows the structural example of the sine wave multiplication part shown in FIG. FIG. 8 is a diagram (part 1) illustrating an example of an internal configuration of a multiplication unit illustrated in FIG. 7; FIG. 8 is a second diagram illustrating an example of an internal configuration of a multiplication unit illustrated in FIG. 7. It is a block diagram of 3rd Example in an antenna evaluation apparatus. It is a figure which shows the structural example of the signal processing part shown in FIG. It is explanatory drawing (the 1) of the example of the orthogonal code sequence produced | generated by an orthogonal code sequence production | generation part. It is explanatory drawing (the 2) of the example of the orthogonal code sequence produced | generated by an orthogonal code sequence production | generation part.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a block diagram of a first embodiment of the antenna evaluation apparatus. Reference numeral 1 indicates an antenna evaluation apparatus, reference numeral 2 indicates an anechoic chamber, reference numeral 10 indicates a time-varying coefficient generator, reference numeral 20 indicates a combined signal generator, and reference numeral 30 indicates a radio frequency (RF). ) Indicates a signal generation unit, and reference numeral 40 indicates an evaluation unit.

Reference symbols T _1v , T _1h ,... T _nv and T _nh indicate transmission antennas, and reference symbols R ₁ and R ₂ indicate antennas to be evaluated. The n transmission antennas T _{1v to} T _nv are antennas for transmitting the vertical polarization component of the test radio wave, and the n transmission antennas T _{1h to} T _nh transmit the horizontal polarization component of the test radio wave. It is an antenna for. n is a natural number.

The antenna evaluation apparatus 1 includes a time-varying coefficient generation unit 10, a combined signal generation unit 20, a radio frequency signal generation unit 30, an evaluation unit 40, and transmission antennas _T1v , _T1h , ... _Tnv and _Tnh . . The transmitting antennas T _1v , T _1h ,... T _nv and T _nh are installed in the anechoic chamber 2 and radiate test radio waves to the antennas R ₁ and R ₂ to be evaluated that are also installed in the anechoic chamber 2. It acts as a scatterer around antennas R ₁ and R ₂ .

When n is an integer of 2 or more, that is, when there are a plurality of transmission antennas T _{1v to} T _nv , each transmission antenna radiates test radio waves subjected to different Doppler displacements from different directions to evaluation target antennas R ₁ and R ₂ . May be. The same applies to the transmission antennas T _{1h to} T _nh .

The time-varying coefficient generator 10 generates time-varying coefficients y _ivj and y _ihj , which are coefficients whose values change with time to represent intensity changes that occur in the test radio wave due to fading fluctuations (1 ≦ i ≦ m, 1 ≦ j ≦ n). The integer m is the number of transmission antennas in the propagation path model simulated by the antenna evaluation apparatus 1. For convenience of explanation, a transmission antenna in a propagation path model simulated by the antenna evaluation apparatus 1 may be referred to as a “virtual antenna”. In addition, the transmitting antennas T _1v , T _1h ,... T _nv and T _nh may be referred to as “scattering antennas”. In addition, the scatterer antennas T _1v , T _1h ,... T _nv and T _nh may be collectively referred to as the scatterer antenna T. The evaluation target antennas R ₁ and R ₂ may be collectively referred to as an evaluation target antenna R.

As will be described later, a correlation is given between the time-varying coefficients y _ivj and y _ihj generated by the time-varying coefficient generating unit 10. For this reason, the time-varying coefficient output from the time-varying coefficient generating unit 10 is expressed as “correlation time-varying coefficient”. The correlation time-varying coefficient y _ivj is a time-varying coefficient that represents a fading fluctuation generated in a transmission radio wave transmitted from the i-th virtual antenna and transmitted from the j-th vertically polarized component scatterer antenna. The correlation time-varying coefficient y _ihj is a time-varying coefficient that represents a fading fluctuation that occurs in the radio wave transmitted from the i-th virtual antenna that is transmitted from the j-th horizontal polarization component scatterer antenna.

A pair of correlated time-varying coefficients y _ivj and y _ihj respectively representing fading fluctuations occurring when transmitting from the scatterer antenna for the jth vertical polarization component and the scatterer antenna for the horizontal polarization component An example of a range “correlated time-varying coefficient pair”.

When the antenna evaluation apparatus 1 simulates a multipath environment, the time varying coefficient generation unit 10 may generate independent time varying coefficients y _ivjk and y _ihjk for each path (1 ≦ i ≦ m, 1 ≦ j ≦ n, 1 ≦ k ≦ p). The integer p is the number of paths included in the multipath.

  FIG. 2 is a diagram illustrating a configuration example of the time-varying coefficient generation unit 10. Reference numeral 11 indicates an initial time-varying coefficient generation unit, and reference numeral 12 indicates a calculation unit. The time varying coefficient generation unit 10 includes an initial time varying coefficient generation unit 11 and a calculation unit 12.

The initial time-varying coefficient generation unit 11 generates a plurality of time-varying coefficients x _ivj and x _ihj that are not correlated with each other (1 ≦ i ≦ m, 1 ≦ j ≦ n). For convenience of explanation, the time-varying coefficients x _ivj and x _ihj are _expressed as “initial time-varying coefficients”. As in other embodiments described later, the plurality of initial time-varying coefficients x _ivj and x _ihj that are not correlated with each other may be a plurality of sine waves having different frequencies or a plurality of different orthogonal code sequences.

The calculation unit 12 multiplies the column vector (x _1vj , x _1hj , x _2vj , x _2hj ,... X _mvj , x _mhj ) having the initial time-varying coefficient as a component by a matrix, thereby using the correlated time-varying coefficient as a component. Column vectors (y _1vj , y _1hj , y _2vj , y _2hj ,... Y _mvj , y _mhj ) are calculated. That is, the calculation unit 12 performs matrix calculation for each of the first to n-th scatterer antennas by multiplying the conversion matrix H _j of (2m) × (2m) as in the following equation (1). Correlation time-varying coefficients y _ivj and y _ihj are calculated.

The correlation of the correlation time-varying coefficients y _ivj and y _ihj can be determined by the value of the transformation matrix H _j . For example, if the transformation matrix H _j is a unit matrix, the correlation time-varying coefficients y _ivj and y _ihj are separate initial time-varying coefficients x _ivj and x _ihj , so the correlation between them is zero. On the other hand, if the components in each row of the transformation matrix H _j are equal, the correlation time-varying coefficients y _ivj and y _ihj are the same coefficient and have the highest correlation value “1”.

In addition, the example of the above formula (1) uses the (2m) × (2m) matrix as the transformation matrix H _j , thereby fading fluctuations of transmission radio waves transmitted from all virtual antennas transmitted for each scatterer antenna. Correlation is given between the correlation time-varying coefficients y _ivj and y _ihj (1 ≦ i ≦ m). Instead, by using s number of transformation matrices H _{j1 to} H _js of (2m / s) × (2m / s) matrix, correlation time variation indicating fading fluctuation of radio waves transmitted from some virtual antennas. A correlation may be provided between the coefficients.

In the example of the following equation (2), the arithmetic unit 12 correlates each other by multiplying two matrix vectors X ₁ and X ₂ each having an initial time-varying coefficient as a component by two matrices H _j1 and H _j2. Two column vectors Y ₁ and Y ₂ having a correlated time-varying coefficient having as components are calculated. Wherein the column vector X ₁ is _{(x 1vj, x 1hj ... x} (m / 2) vj, x (m / 2) hj), column vector X ₂ is _{(x (m / 2 + 1} ) vj, x _{(m / 2 + 1) hj} ... x _mvj , x _mhj ). The column vector Y ₁ is (y _1vj , y _1hj ... Y _{(m / 2) vj} , y _{(m / 2) hj} ), and the column vector Y ₂ is (y _{(m / 2 + 1) vj} , y _{(m / 2 + 1) hj} ... y _mvj , y _mhj ).

Y ₁ = H _j1 X ₁ , Y ₂ = H _j2 X ₂ (1 ≦ j ≦ n) (2)

  The example of Formula (2) determines the correlation between the correlation time-varying coefficients indicating the fading fluctuation of the transmission radio wave transmitted from the first to (m / 2) -th virtual antennas transmitted for each scatterer antenna. be able to. Further, the example of Expression (2) can determine the correlation between the correlation time-varying coefficients indicating the fading fluctuations of the transmission radio waves from the (m / 2 + 1) th to m-th virtual antennas.

A different conversion matrix may be used for each scatterer antenna as the conversion matrix H _j or H _{j1 to} H _js , and the same conversion matrix may be used in common among the scatterer antennas.

When the antenna evaluation apparatus 1 simulates a multipath environment, the initial time-varying coefficient generation unit 11 may generate independent initial time-varying coefficients x _ivjk and x _ihjk for each path (1 ≦ i ≦ m, 1 ≦ j ≦ n, 1 ≦ k ≦ p). The calculation unit 12 performs the above matrix calculation for each path, and calculates correlation time-varying coefficients y _ivjk and y _ihjk . When performing matrix calculation, the calculation unit 12 may use conversion matrices H _j and H _{j1 to} H _js having different values for each path, or may use the same conversion matrix in common between the paths. .

Please refer to FIG. The time varying coefficient generation unit 10 outputs the correlation time varying coefficients y _ivj and y _ihj to the combined signal generation unit 20. The composite signal generation unit 20 generates a composite signal by multiplying the correlation time-varying coefficients y _ivj and y _ihj by the baseband signal B _i (1 ≦ i ≦ m) transmitted from each virtual antenna.

  FIG. 3 is a diagram illustrating a configuration example of the combined signal generation unit 20. Reference numeral 21 indicates a time-varying coefficient multiplication unit, and reference numeral 22 indicates a synthesis unit. The synthesized signal generator 20 includes a time-varying coefficient multiplier 21 and a synthesizer 22.

The time-varying coefficient multiplier 21 multiplies the correlation time-varying coefficients y _ivj and y _ihj by the baseband signal B _i according to the following equation (3) to calculate the multiplied values v _ivj and v _ihj .

v _ivj = B _i × y _ivj , v _ihj = B _i × y _ihj (1 ≦ i ≦ m, 1 ≦ j ≦ n) (3)

The synthesizer 22 synthesizes the multiplication values v _ivj and v _ihj according to the following equation (4), thereby synthesizing signals z _1v , z transmitted from the transmission antennas T _1v , T _1h ,... T _nv and T _{nh. 1h} ,... Z _nv and z _{nh are} generated.

When the antenna evaluation apparatus 1 simulates a multipath environment, the time-varying coefficient multiplier 21 delays the baseband signal B _i by a delay time corresponding to each path. The time-varying coefficient multiplier 21 calculates the multiplied values v _ivjk and v _ihjk by multiplying the baseband signal B _i whose delay is adjusted by the correlation time-varying coefficients y _ivjk and y _ihjk according to the following equation (5). To do.

v _ivjk = B _i × y _ivjk , v _ihjk = B _i × y _ihjk (1 ≦ i ≦ m, 1 ≦ j ≦ n, 1 ≦ k ≦ p) (5)

The combining unit 22 may generate combined signals z _1v , z _1h ,... Z _nv and z _nh by combining the multiplied values v _ivjk and v _ihjk according to the following equation (6).

The synthesizer 22 may generate synthesized signals z _1v , z _1h ,... Z _nv and z _nh by weighting and synthesizing the multiplied values v _ivjk and v _ihjk according to the following equation (7). In the following formula (7), w _k is a weighting coefficient.

Please refer to FIG. The time varying coefficient generation unit 10 outputs the combined signals z _jv and z _jh to the radio frequency signal generation unit 30. Radio frequency signal generator 30 by modulating a carrier wave by a synthetic signal z _jv and z _jh, or by converting the frequency of the synthesis signal z _jv and z _jh, transmitted from the scatterer antennas T _jv and T _jh Generating a radio frequency signal.

For example, the radio frequency signal generation unit 30 may generate radio frequency signals having different frequencies by receiving different Doppler displacements as radio frequency signals transmitted from the scatterer antennas T _jv and T _jh .

  When the evaluation target antenna R receives the test radio wave transmitted from the scatterer antenna T, the evaluation unit 40 evaluates the antenna characteristics of the evaluation target antenna R. Evaluation items for antenna characteristic evaluation by the evaluation unit 40 may include, for example, a transmission rate, a throughput, and an error rate.

Next, a method for determining the transformation matrices H _j and H _{j1 to} H _js used in the matrix calculation for calculating the correlation time-varying coefficients y _ivj and y _ihj in the calculation unit 12 will be described. As described above, because of the conversion between the vertical polarization component and the horizontal polarization component generated in the propagation path, the correlation between the radio wave intensity fluctuation, that is, the fading fluctuation correlation between the vertical polarization component and the horizontal polarization component. May occur.

  In order to express the correlation of the component intensity converted between the vertical polarization component and the horizontal polarization component for a certain propagation path, it is necessary to share each propagation channel coefficient between the vertical polarization component and the horizontal polarization component. A polarization matrix covariance matrix Γ, which is a dispersion matrix, is used. For example, 3GPP contribution R4-060334 proposes the values of the inter-polarization covariance matrix Γ assumed in several different system scenarios and the spatial correlation matrix of the base station device and the mobile station device. .

FIG. 4A is an explanatory diagram of a transmission path model in which a correlation between polarizations is represented by an inter-polarization covariance matrix Γ. The transmission path model in FIG. 4A has four channels 50 to 53. The channel 50 is a channel in which the vertically polarized wave component at the transmitting antenna that is the transmitting end of the transmission path model reaches the receiving antenna that is the receiving end as the vertically polarized wave component, and the channel coefficient is expressed as g _{v → v} . write. The channel 51 is a channel in which the vertical polarization component in the transmission antenna reaches the reception antenna as a horizontal polarization component, and the channel coefficient is expressed as g _{v → h} .

The channel 52 is a channel in which the horizontal polarization component in the transmission antenna reaches the reception antenna as a vertical polarization component, and the channel coefficient is expressed as g _{h → v} . The channel 53 is a channel in which the horizontal polarization component in the transmission antenna reaches the reception antenna as a horizontal polarization component, and the channel coefficient is expressed as g _{h → h} .

The inter-polarization covariance matrix Γ is given by the following equation (8) as a covariance matrix of these channel coefficients. In Expression (8), “x ^* ” means a conjugate complex number of complex number x, and “E [x]” means an average of x.

  In the antenna evaluation apparatus 1 shown in FIG. 1, the test radio wave transmitted from the scatterer antenna T arrives at the evaluation target antenna R as it is, so that a vertical deviation is generated in the transmission path between the scatterer antenna T and the evaluation target antenna R. Conversion of the component between the wave component and the horizontal polarization component does not occur. Therefore, by transmitting the vertical and horizontal polarization components similar to the vertical and horizontal polarization components arriving at the antenna R to be evaluated from the scatterer antenna T, the inter-polarization correlation given by the given inter-polarization covariance matrix Γ A transmission line model that produces

  FIG. 4B is an explanatory diagram of a radio wave propagation path model in the antenna evaluation apparatus 1. For simplicity of explanation, the channel coefficient h from the scatterer antenna T to the evaluation target antenna R is set to “1”. The vertical and horizontal polarization components transmitted from the virtual antenna simulated by the antenna evaluation apparatus 1 propagate through the virtual channel simulating the channels 50 to 53 and reach the scatterer antenna T. The vertically and horizontally polarized components that have reached the scatterer antenna T reach the antenna R to be evaluated as they are.

When the vertical and horizontal polarization components at the position of the virtual antenna have unit intensity, the radio wave intensities of the vertical polarization component and horizontal polarization component reaching the antenna R to be evaluated are “g _{v → v} + g _{h → v} ”, respectively. And “g _{v → h} + g _{h → h} ”. For this reason, the radio wave intensities of the vertical polarization component and horizontal polarization component to be transmitted from the scatterer antenna T are similarly “g _{v → v} + g _{h → v} ” and “g _{v → h} + g _{h → h} ”. is there.

  Therefore, when the correlation similar to the correlation between polarizations by the polarization covariance matrix Γ in the equation (8) is given, the correlation of the radio field intensity between the vertical and horizontal polarization components transmitted from the scatterer antenna T is , Can be represented by a covariance matrix Q shown in the following equation (9). The covariance matrix Q is a covariance matrix of the radio field intensity of the vertical and horizontal polarization components transmitted from the scatterer antenna T when the vertical and horizontal polarization components at the position of the virtual antenna have unit intensity. As can be seen from Equation (9), each component of the covariance matrix Q can be calculated using each component of the inter-polarization covariance matrix Γ of Equation (8).

In the simulation of the virtual antenna, the covariance matrix of the radio field intensity of the vertical and horizontal polarization components transmitted from the scatterer antenna T is the spatial correlation matrix R _t and covariance matrix Q given for the simulated virtual antenna. Calculated by the Kronecker product.

Consider a case where a spatial correlation matrix R _t of a virtual antenna that is a multi-antenna including m antennas is given by the following equation.

Further, when the vertical and horizontal polarization components at the position of the virtual antenna have unit intensity, the radio waves of the vertical and horizontal polarization components transmitted from the j-th (1 ≦ j ≦ n) scatterer antennas T _jv and T _jh The intensity covariance matrix is denoted Q _j . The covariance matrix R _j of the radio field intensity of the vertical and horizontal polarization components transmitted from the jth scatterer antennas T _jv and T _jh is given by the following equation (10).

Indicates the Kronecker product. On the other hand, the adjoint matrix of the transformation matrix H _j is

Is written. The covariance matrix R _j is equal to the product of the transformation matrix H _j and its adjoint matrix as shown in the following equation (11).

This is because the above-mentioned correlation time-varying coefficients y _ivj and y _ihj represent the intensity change of the test radio wave transmitted from the scatterer antennas T _1jv and T _jh, so the covariance matrix R _j is the correlation time-varying coefficient y _ivj , Y _ihj can be expressed as the following equation (12).

As shown in the above equation (1), a vector (y _1vj , y _1hj , y _2vj , y _2hj ,... Y _mvj , y _mhj ) having a correlation time-varying coefficient as a component is a vector having an initial time-varying coefficient as a component. (X _1vj , x _1hj , x _2vj , x _2hj ,... X _mvj , x _mhj ) and the transformation matrix H _j . Therefore, the above equation (12) can be transformed into the following equation (13).

Since the initial time-varying coefficients x _1vj , x _1hj , x _2vj , x _2hj ,... X _mvj , x _mhj are uncorrelated with each other, the right side of the second equation in the term of equation (13)

Becomes the unit matrix I. Therefore, finally, the covariance matrix R _j is the product of the transformation matrix H _j and its adjoint matrix, as shown in Equation (14).

The transformation matrix H _j whose product with the adjoint matrix is the covariance matrix R _j can be calculated by eigenvalue decomposition of the covariance matrix R _j , for example. Alternatively, the transformation matrix H _j may be calculated by performing Cholesky decomposition on the covariance matrix R _j .

  According to the present embodiment, when an inter-polarization covariance matrix Γ is given for a certain propagation path model, a vertical polarization component and a horizontal polarization component generated at the position of the receiving antenna corresponding to the inter-polarization covariance matrix Γ. It is possible to reproduce the correlation between the two.

  Subsequently, another embodiment of the antenna evaluation apparatus will be described. FIG. 5 is a configuration diagram of the second embodiment of the antenna evaluation apparatus. Reference numeral 60 indicates a signal processing unit, reference numeral 61 indicates a baseband (BB) signal generation unit, reference numeral 62 indicates an analog-digital converter (ADC), and reference numeral 63 indicates an output processing unit. Components similar to those shown in FIG. 1 are denoted by the same reference numerals as those used in FIG.

The antenna evaluation device 1 includes a signal processing unit 60, a baseband signal generation unit 61, a radio frequency signal generation unit 30, an evaluation unit 40, and a scatterer antenna T. The baseband signal generator 61 generates a baseband signal for generating a test radio wave. The signal processing unit 60 generates a composite signal by multiplying the baseband signal generated by the baseband signal generation unit 61 by the correlation time-varying coefficients y _ivjk and y _ihjk described above.

In the present embodiment, the signal processing unit 60 generates the above-described correlation time-varying coefficients y _ivjk and y _ihjk by linearly combining a plurality of initial time-varying coefficients that are a plurality of sine waves having different frequencies. The signal processing unit 60 includes a time-varying coefficient generation unit 10, a combined signal generation unit 20, an analog / digital converter 62, and an output processing unit 63.

  FIG. 6 is a diagram illustrating a configuration example of the signal processing unit 60 illustrated in FIG. 5. Reference numeral 70 indicates a signal generation unit, and reference numeral 72-ik indicates a sine wave generation unit (1 ≦ i ≦ m, 1 ≦ k ≦ p). For convenience of explanation, the sine wave generator 72-ik may be collectively referred to as a sine wave generator 72.

  Reference numeral 80 denotes a sine wave multiplication unit, reference numerals 65-1v to 65-nv and reference numerals 65-1h to 65-nh denote digital-analog converters (DACs), and reference numerals 66-1v to 66- nv and reference numerals 66-1h to 66-nh indicate filters. Reference numerals BB1 to BBm denote baseband signals transmitted from m virtual antennas in the propagation path model.

The time varying coefficient generation unit 10 includes a signal generation unit 70 and a calculation unit 12. The signal generation unit 70 includes (m × p) sine wave generation units 72. Each sine wave generator 72 generates (2 × n) sine waves as the initial time-varying coefficients. The (2 × n) sine waves generated by the sine wave generation unit 72-ik are described as x _ivjk and x _ihjk (1 ≦ i ≦ m, 1 ≦ k ≦ p, 1 ≦ j ≦ n). For convenience of explanation, the sine wave generated by the sine wave generator 72 may be described as an initial sine wave.

  The (2 × m × n × p) initial sine waves generated by the sine wave generation unit 72 have different frequencies. The periods of these initial sine waves may be periods that are relatively prime to each other. Here, the prime relationship is a relationship in which there is no common divisor other than 1. Generating a correlation time-varying coefficient by linearly combining initial sine waves with mutually prime periods can make the period of the correlation time-varying coefficient longer than when linearly combining sine waves with non-prime periods. The period of the fading fluctuation represented by the correlation time-varying coefficient can be lengthened.

The initial sine wave generated by the sine wave generation unit 72 is input to the calculation unit 12. Now, for each of the subscripts j and k (1 ≦ j ≦ n, 1 ≦ k ≦ p), column vectors (x _1vjk , x) having initial sine wave components x _ivjk and x _ihjk (1 ≦ i ≦ m) as components. _{1hjk, x 2vjk, x 2hjk,} ... x mvjk, x mhjk) are listed as X _jk. Further, for each of the subscripts j and k (1 ≦ j ≦ n, 1 ≦ k ≦ p), column vectors (y _1vjk , y) whose components are correlation time-varying coefficients y _ivjk and y _ihjk (1 ≦ i ≦ m) are _used . _{1hjk, y 2vjk, y 2hjk,} ... y mvjk, y mhjk) are listed as Y _jk.

The arithmetic unit 12 multiplies each column vector X _jk (1 ≦ j ≦ n, 1 ≦ k ≦ p) by the transformation matrix H _jk as shown in the following equation (15), thereby (2 × m × n × p) Calculate the correlation time-varying coefficients y _ivjk and y _ihjk (1 ≦ j ≦ n, 1 ≦ i ≦ m, 1 ≦ k ≦ p).

The transformation matrix H _jk is a given inter-polarization covariance according to the transmission path model to be simulated, as in the method for determining the transformation matrix H _j described with reference to the equations (8) to (14). It is determined according to the matrix Γ. The calculation unit 12 may include a storage unit that holds the transformation matrix H _jk .

The calculation unit 12 uses a conversion matrix H _jk having a different value of the subscript j, that is, a conversion matrix H _jk used for calculation of a correlation time-varying coefficient representing a fading fluctuation of a test radio wave transmitted from different scatterer antennas. An equal matrix may be used. In addition, the calculation unit 12 may use different matrices as the conversion matrix H _jk having different values of the subscript j.

The calculation unit 12 uses a conversion matrix H _jk having a different value of the subscript k, that is, a conversion matrix H _jk used for calculating a correlation time-varying coefficient representing a fading fluctuation of a test radio wave passing through different paths among multipaths. Different matrices may be used. In addition, the arithmetic unit 12 may use matrices that are equal to each other as the transformation matrix H _jk having different values of the subscript k.

The correlation time-varying coefficients y _ivjk and y _ihjk are input to the composite signal generation unit 20. The synthesized signal generation unit 20 includes a sine wave multiplication unit 80 and a synthesis unit 22. The sine wave multiplication unit 80 multiplies the baseband signal BBi by the correlation time-varying coefficients y _ivjk and y _ihjk to irradiate the i th through the k th path radiated from each j th scatterer antenna. The components v _ivjk and v _ihjk of the baseband signal _BBi are calculated.

FIG. 7 is a diagram illustrating a configuration example of the sine wave multiplication unit 80 illustrated in FIG. 6. FIG. 7 shows a configuration example when m = “4”, n = “4”, and p = “9”. “M” is the number of virtual antennas in the propagation path model, that is, the number of baseband signals. “N” is the number of scatterer antennas T _jv for transmitting the vertical polarization component of the test radio wave or the number of scatterer antennas T _jh for transmitting the horizontal polarization component of the test radio wave. “P” is the number of paths included in the multipath.

  Reference numerals 82-11 to 82-19, 82-21 to 82-29, 82-31 to 82-39, and 82-41 to 82-49 indicate multiplication units. Reference numerals 83-11 to 83-18, 83-21 to 83-28, 83-31 to 83-38, and 83-41 to 83-48 denote delay units. The sine wave multiplication unit 80 includes multiplication units 82-11 to 82-19, multiplication units 82-21 to 82-29, multiplication units 82-31 to 82-39, and multiplication units 82-41 to 82-49. The sine wave multiplication unit 80 includes delay units 83-11 to 83-18, delay units 83-21 to 83-28, delay units 8331 to 83-38, and delay units 8341 to 83-48. .

Each multiplier 82-i1 (1 ≦ i ≦ m) performs a process of calculating a component that passes through the first path included in the multipath. The baseband signal BBi converted into the digital format by the analog-digital converter 62 is input to the multiplier 82-i1 without delay. Each multiplier unit 82-i1, by multiplying the baseband signal BBi varying coefficient when the correlation in _y iv11 ~y ivn1 and _y ih11 ~y ihn1, multiply showing the component passing through the first-th paths in the multipath to calculate the value _v iv11 ~v ivn1 and _v ih11 ~v ihn1. As an example, FIG. 8 shows an internal configuration of the multiplication unit 82-11. The multiplier 82-11 includes a multiplier for multiplying the baseband signal BB1 by the correlation time-varying coefficients y _{1v11 to} y _1v41 and y _{1h11 to} y _1h41 , respectively.

Please refer to FIG. Each multiplier 82-i2 (1 ≦ i ≦ m) performs a process of calculating a component that passes through the second path included in the multipath. The digital baseband signal BBi is given a delay amount D1 by the delay unit 83-i1, and then input to the multiplication unit 82-i2. Each multiplier unit 82-i1, by multiplying the baseband signal BBi varying coefficient when the correlation in _{y iv12} ~y ivn2 and _y ih12 ~y ihn2, multiplication value indicating the component passing through the second second pass v _IV12 to v to calculate the _ivn2 and _v ih12 ~v ihn2. As an example, FIG. 8 shows an internal configuration of the multiplier 82-12.

Hereinafter, similarly, a process of calculating a component passing through the kth path (3 ≦ k ≦ p) included in the multipath is performed. The baseband signal BBi output from the preceding delay unit 83-i (k-2) is input to each stage delay unit 83-i (k-1). Therefore, the baseband signal BBi having the delay amount (D1 +... + D (k−1)) is input to the multiplier 82-ik at each stage. Multiplying unit 82-ik of each stage, in such a baseband signal BBi, by multiplying the time correlation varying coefficient _y iv1k ~y ivnk and _y ih1k ~y ihnk, multiplication value that indicates the component passing through the k-th path v to calculate the _{iv1k ~v ivnk} and _v ih1k ~v ihnk. As an example, FIG. 9 shows an internal configuration of the multiplier 82-19.

  By applying different delay amounts for each path to the baseband signal BBi (1 ≦ i ≦ m, 1 ≦ k ≦ p) by each delay unit 83-i (k−1), by combining signals passing through the multipath Fading environment can be reproduced.

The multiplication values v _ivjk and v _ihjk are input to the combining unit 22 shown in FIG. The synthesizer 22 generates synthesized signals z _1v , z _1h ,... Z _nv and z _nh by weighting and synthesizing the multiplied values v _ivjk and v _ihjk according to the above equation (7).

The synthesized signals z _1v , z _1h ,... Z _nv and z _nh are input to the output processing unit 63. The output processing unit 63 includes digital / analog converters 65-1v to 65-nv and 65-1h to 65-nh, and filters 66-1v to 66-nv and 66-1h to 66-nh. The digital-analog converters 65-1v and 65-1h convert the synthesized signals z _1v and z _1h into analog signals, respectively. Similarly, the digital-analog converters 65-jv and 65-jh (2 ≦ j ≦ n) respectively convert the combined signals z _jv and z _jh into analog signals.

Filter 66-1v and 66-1h is respectively filters the combined signal z _{1 v} and z _1h in analog form, to remove aliasing generated during the digital-analog conversion. Similarly, the filters 66-jv and 66-jh (2 ≦ j ≦ n) respectively filter the analog synthesized signals z _jv and z _jh , respectively. The combined signals z _{1v to} z _nv and z _{1h to} z _nh after passing through the filters 66-1v to 66-nv and 66-1h to 66-nh are respectively _denoted as Dout1v to Doutnv and Dout1h to Doutnh.

The combined signals Doutjv and Doutjh are input to the radio frequency signal generation unit 30 shown in FIG. The radio frequency signal generation unit 30 modulates the carrier wave with the combined signals Doutjv and Doutjh, or converts the frequency of the combined signals Doutjv and Doutjh, thereby transmitting the radio frequency signals transmitted from the scatterer antennas T _jv and T _jh. Is generated.

  In this embodiment, a correlation time-varying coefficient that gives a fading fluctuation to a test radio wave is generated by linearly combining a plurality of sine waves having different frequencies. According to the present embodiment, it is possible to give a correlation corresponding to a given inter-polarization covariance matrix Γ between the vertical polarization component and the horizontal polarization component of the correlation time-varying coefficient.

  Next, still another embodiment of the antenna evaluation apparatus will be described. FIG. 10 is a configuration diagram of a third embodiment of the antenna evaluation apparatus. Reference numeral 67 indicates a data series generation unit. Constituent elements similar to those shown in FIG. 5 are denoted by the same reference numerals as those used in FIG. The antenna evaluation apparatus 1 includes a signal processing unit 60, a radio frequency signal generation unit 30, an evaluation unit 40, and a scatterer antenna T.

  In various wireless communication systems, packet-coded data is transmitted in channel-coded data in units of data length called channel coding units. Such wireless communication systems include, for example, LTE (Long Term Evolution), WiMAX (Worldwide Interoperability for Microwave Access), W-CDMA (Wideband-Code Division Multiple Access), and WLAN (Wireless Local Area Network).

  If the fluctuation of the transmission path of the test radio wave is continuous within the channel coding unit and the evaluation unit 40 performs the antenna evaluation within the channel coding unit, the fluctuation of the transmission path between the channel coding units is discontinuous. There is no problem.

  Therefore, the antenna evaluation apparatus 1 according to the present embodiment uses a data sequence as a baseband signal, and generates a sequence of data sequences by concatenating a plurality of data sequences in a predetermined channel coding unit.

  Then, the antenna evaluation apparatus 1 multiplies the data sequence column by the code sequence as the correlation time-varying coefficient described above. That is, each data series included in the data series column is multiplied by each code included in the code series. The antenna evaluation device 1 generates a fading environment in a simulated manner by transmitting a data sequence multiplied by each code included in the code sequence as a test signal.

  The antenna evaluation apparatus 1 also includes a plurality of data sequences obtained by multiplying the same data sequence in the channel coding unit by each code included in the code sequence instead of multiplying the sequence of baseband signal data sequences by the code sequence. May be generated.

This code sequence is a time-varying coefficient because it is a sequence of a plurality of codes multiplied by each data sequence transmitted sequentially at each time. As will be described later, in this code sequence, a correlation is generated between the vertical polarization component and the horizontal polarization component of the radio wave radiated from the scatterer antenna T according to a given inter-polarization covariance matrix Γ. A predetermined correlation is given. Therefore, this code sequence is given as an example of the correlation time-varying coefficients y _ivjk and y _ihjk described above.

The signal processing unit 60 generates a composite signal by multiplying the sequence of the data series by the code series y _ivjk and y _ihjk given the correlation. In this embodiment, the signal processing unit 60 generates code sequences y _ivjk and y _ihjk by linearly combining different orthogonal code sequences. The signal processing unit 60 includes a data series generation unit 67, a time-varying coefficient generation unit 10, a combined signal generation unit 20, and an output processing unit 63.

  FIG. 11 is a diagram illustrating a configuration example of the signal processing unit 60 illustrated in FIG. 10. Components similar to those shown in FIG. 6 are denoted by the same reference symbols as those used in FIG. Reference numeral 90 indicates an orthogonal code generator, reference numeral 91-ik indicates an orthogonal code sequence generator (1 ≦ i ≦ m, 1 ≦ k ≦ p), and reference numeral 92 indicates a code sequence multiplier. For convenience of explanation, the orthogonal code sequence generation unit 91-ik may be collectively referred to as an orthogonal code sequence generation unit 91 in some cases. Reference numerals X1 to Xm indicate data sequences as baseband signals transmitted from m virtual antennas in the propagation path model.

The time varying coefficient generation unit 10 includes an orthogonal code generation unit 90 and a calculation unit 12. The orthogonal code generation unit 90 includes (m × p) orthogonal code sequence generation units 91. Each orthogonal code sequence generation unit 91 generates (2 × n) orthogonal code sequences as the initial time-varying coefficients. The orthogonal code sequence generated by each orthogonal code sequence generation unit 91-ik is _expressed as x _iv1k , x _ih1k , x _iv2k , x _ih2k , x _iv3k , x _ih3k , x _iv4k and x _ih4k (1 ≦ i ≦ m, 1 ≦ k ≦ p). For convenience of explanation, in the following explanation regarding this embodiment, a case where m = “4”, n = “4”, and p = “9” will be explained.

Each orthogonal code sequence generation unit 91 ^periodically generates, for example, a Walsh code, a code related to a Fourier series of {e ^{j2πnk / N} , (n, k = 0,1,..., N−1)}, and an M sequence. A code that is shifted and added with 1 at the end may be generated as an orthogonal code sequence.

For easy understanding, an orthogonal code sequence generated by each orthogonal code sequence generation unit will be described with reference to FIGS. 12 and 13. As examples of the orthogonal code sequence generation unit, an orthogonal code sequence generation unit 91-11 and an orthogonal code sequence generation unit 91-21 will be described. The orthogonal code sequence generation unit 91-11 generates eight orthogonal code sequences _x1v11 , _x1h11 , _x1v21 , _x1h21 , _x1v31 , _x1h31 , _x1v41, and _x1h41 .

For example, the orthogonal code sequence x _1v11 includes exp (jθ _1v11 ), exp (jθ _1v11 ), exp (jθ _1v11 ), exp (jθ _1v11 ), exp (jθ _1v11 ), exp (jθ _1v11 ), exp (jθ _1v11 ) and It is a code string having eight codes of exp (jθ _1v11 ).

Further, for example orthogonal code sequence x _{1H11 is, exp (jθ 1h11), exp} (jθ 1h11), exp (jθ 1h11), exp (jθ 1h11), - exp (jθ 1h11), - exp (jθ 1h11), - exp ( jθ _1h11 ) and _−exp (jθ _1h11 ). The phases θ _1v11 and θ _1h11 may be random numbers in the range 0-2π.

On the other hand, the orthogonal code sequence generation unit 91-21 generates eight orthogonal code sequences _x2v11 , _x2h11 , _x2v21 , _x2h21 , _x2v31 , _x2h31 , _x2v41, and _x2h41 . For example orthogonal code sequence x _{2V11 is, exp (jθ 2v11), exp} (jθ 2v11), - exp (jθ 2v11), - exp (jθ 2v11), exp (jθ 2v11), exp (jθ 2v11), - exp (jθ _2v11 ) and _-exp (jθ _2v11 ).

Further, for example orthogonal code sequence x _{2H11 is, exp (jθ 2h11), exp} (jθ 2h11), - exp (jθ 2h11), - exp (jθ 2h11), - exp (jθ 2h11), - exp (jθ 2h11), exp It is a code string having eight codes (jθ _2h11 ) and exp (jθ _2h11 ). The phases θ _2v11 and θ _2h11 may be random numbers in the range 0-2π. Similarly, the other orthogonal code sequence generation units 91 also generate orthogonal code sequences having 8 codes, respectively.

The orthogonal code sequence generated by the orthogonal code sequence generation unit 91 is input to the calculation unit 12. Now, for each of the subscripts j and k (1 ≦ j ≦ 4,1 ≦ k ≦ 9), the orthogonal code sequence _x 1vjk, x 1hjk, column vector _(x 1vjk to components x _2Vjk and _x 2hjk, x 1hjk, x _2vjk , x _2hjk ) is described as X _jk1 . Further, the orthogonal code sequence _x 3vjk, x 3hjk, column vector with components x _4Vjk and _{x 4hjk (x 3vjk, x 3hjk} , x 4vjk, x 4hjk) are listed as X _jk2.

For each of the subscripts j and k (1 ≦ j ≦ 4, 1 ≦ k ≦ 9), the column vectors (y _1vjk , y _1hjk , y) having the code sequences y _1vjk , y _1hjk , y _2vjk and y _2hjk as components. _2vjk , _y2hjk ) is written as _Yjk1 . Further, the code sequence _y 3vjk, y 3hjk, y 4vjk and y _4Hjk the a component column vector _{(y 3vjk, y 3hjk, y} 4vjk, y 4hjk) are listed and Y _jk2.

The arithmetic unit 12 multiplies each column vector X _jk1 (1 ≦ j ≦ 4, 1 ≦ k ≦ 9) by the transformation matrix H _jk1 as shown in the following equation (16), _{thereby obtaining} (m × n × p). = (4 × 4 × 9) code sequences y _ivjk and y _ihjk are calculated (1 ≦ j ≦ 4, i = 1, 2, 1 ≦ k ≦ 9). Further, the arithmetic unit 12 multiplies each column vector X _jk2 (1 ≦ j ≦ 4, 1 ≦ k ≦ 9) by the transformation matrix H _jk2 as shown in the following equation (17), _{thereby obtaining} (4 × 4 × 9) The code sequences y _ivjk and y _ihjk are calculated (1 ≦ j ≦ 4, i = 3, 4, 1 ≦ k ≦ 9).

The transformation matrices H _jk1 and H _jk2 are determined according to a given inter-polarization covariance matrix Γ, similarly to the method for determining the transformation matrix H _j described with reference to the equations (8) to (14). The computing unit 12 may include a storage unit that holds the transformation matrices H _jk1 and H _jk2 . By generating the code sequences y _ivjk and y _ihjk according to the above equations (16) and (17), the correlation according to the inter-polarization covariance matrix Γ between the code sequences y _ivjk and y _ihjk having the same subscript j Can have sex.

The calculation unit 12 uses a transformation matrix H _jk1 having a different value of the subscript j, that is, a transformation matrix H _jk1 used for calculating a correlation time-varying coefficient representing a fading fluctuation of a test radio wave transmitted from each scatterer antenna. An equal matrix may be used. In addition, the calculation unit 12 may use different matrices as the conversion matrix H _jk1 having different values of the subscript j. The same applies to the transformation matrix H _jk2 .

The calculation unit 12 uses a transformation matrix H _jk1 having a different value of the subscript k, that is, a transformation matrix H _jk1 used for calculating a correlation time-varying coefficient representing a fading fluctuation of a test radio wave passing through different paths among multipaths. Different matrices may be used. Further, the calculation unit 12 may use matrices that are equal to each other as the conversion matrix H _jk1 having different values of the subscript k. The same applies to the transformation matrix H _jk2 .

The code sequences y _ivjk and y _ihjk are input to the composite signal generation unit 20. The synthesized signal generation unit 20 includes a code sequence multiplication unit 92 and a synthesis unit 22. The code sequence multiplying unit 92 multiplies the data sequence Xi by the code sequences y _ivjk and y _ihjk to radiate from each jth scatterer antenna and pass through the kth path. v _ivjk and v _ihjk are calculated.

Now, the code sequence y _Ivjk, expressed as the code sequence containing eight codes _{y v1 ~y v8 {y v1,} y v2, y v3, y v4, y v5, y v6, y v7, y v8}. The code sequences _y ihjk, expressed as the code sequence containing eight codes _{y h1 ~y h8 {y h1,} y h2, y h3, y h4, y h5, y h6, y h7, y h8}.

The code sequence multiplying unit 92 multiplies the data sequence Xi of the channel coding unit by eight codes included in the code sequence y _ivjk , respectively, so that the signal components v _ivjk = {y _v1 × Xi, y _v2 × Xi, y _v3 * Xi, _yv4 * Xi, _yv5 * Xi, _yv6 * Xi, _yv7 * Xi, _yv8 * Xi} are calculated. The signal component v _ivjk is a sequence of data series including eight data series (y _v1 × Xi) to (y _v8 × Xi). Similarly, the code sequence multiplying unit 92 multiplies the data sequence Xi of the channel coding unit by 8 codes included in the code sequence y _ihjk , respectively, _{thereby obtaining} signal components v _ihjk = {y _h1 × Xi, y _h2 × Xi. , Y _h3 × Xi, y _h4 × Xi, y _h5 × Xi, y _h6 × Xi, y _h7 × Xi, y _h8 × Xi} are calculated.

The signal components v _ivjk and v _ihjk are input to the synthesis unit 22. The synthesizer 22 generates synthesized signals z _1v , z _1h ,... Z _nv and z _nh by weighting and synthesizing the signal components v _ivjk and v _ihjk according to the above equation (7). Each composite signal z _1v , z _1h ,... Z _nv and z _nh is also a sequence of data series including eight data series.

Each data series included in each column of the synthesized signals z _1v , z _1h ,... Z _nv and z _nh is sequentially input to the output processing unit 63. The digital-analog converters 65-1v and 65-1h convert each data series included in the synthesized signals z _1v and z _1h into analog signals, respectively. Similarly, the digital-analog converters 65-jv and 65-jh (2 ≦ j ≦ n) respectively convert the data series included in the combined signals z _jv and z _jh into analog signals, respectively.

The filters 66-1v and 66-1h filter the combined signals z _1v and z _1h to remove aliasing distortion generated during digital-analog conversion. Similarly, the filters 66-jv and 66-jh (2 ≦ j ≦ n) respectively filter the synthesized signals z _jv and z _jh , respectively. The combined signals Dout1v to Doutnv and Dout1h to Doutnh after passing through the filters 66-1v to 66-nv and 66-1h to 66-nh are input to the radio frequency signal generator 30 shown in FIG. The processing by the radio frequency signal generation unit 30 is the same as the processing described with reference to FIG.

The data series Xi multiplied by the code series y _ivjk and y _ihjk having the subscript j is transmitted from the j-th scatterer antennas T _jv and T _jh for the vertical and horizontal polarization components, respectively. That is, the code sequences y _ivjk and y _ihjk represent fading fluctuations generated in the vertical polarization component and the horizontal polarization component of the test radio wave transmitted from the scatterer antennas T _jv and T _jh , respectively.

On the other hand, the code sequences y _ivjk and y _ihjk having the same subscript j have a correlation according to the _inter- polarization covariance matrix Γ by the matrix operations of the above equations (16) and (17). Therefore, the fading fluctuations generated in the vertical polarization component and horizontal polarization component of the test radio waves transmitted from the scatterer antennas T _jv and T _jh have a correlation according to the inter-polarization covariance matrix Γ.

  In this embodiment, as a correlation time-varying coefficient, a code sequence that gives a fading fluctuation to a test radio wave is generated by linearly combining different orthogonal code sequences. According to the present embodiment, it is possible to give a correlation corresponding to a given inter-polarization covariance matrix Γ between the vertical polarization component and the horizontal polarization component of such a code sequence.

  The following additional notes are further disclosed with respect to the embodiment including the above examples.

(Appendix 1)
A time-varying coefficient generating unit that generates a pair of correlated time-varying coefficients that are correlated with each other;
A composite signal generation unit that generates a composite signal by multiplying a baseband signal by the correlation time-varying coefficient;
A transmitting antenna that transmits test radio waves each having a composite signal generated by multiplying a pair of correlation time-varying coefficients to a baseband signal in a vertical polarization component and a horizontal polarization component to an antenna to be evaluated, respectively. Prepared,
The time-varying coefficient generation unit is a predetermined inter-polarization covariance matrix that defines a covariance matrix of each propagation channel coefficient between the vertical polarization component and the horizontal polarization component at the transmission end and the reception end of the propagation path model. An antenna evaluation apparatus that gives a correlation of a correlation amount between a vertical polarization component and a horizontal polarization component at the receiving end to the pair of correlation time-varying coefficients.

(Appendix 2)
The antenna evaluation apparatus according to appendix 1, wherein the time-varying coefficient generation unit gives a correlation based on a different polarization covariance matrix to the pair of correlated time-varying coefficients for each path included in the multipath.

(Appendix 3)
A plurality of transmitting antennas for transmitting the test radio waves from different directions;
The antenna evaluation apparatus according to appendix 1, wherein the time-varying coefficient generation unit gives a correlation based on a common inter-polarization covariance matrix to the pair of time-varying signals among the plurality of transmission antennas.

(Appendix 4)
The time-varying coefficient generating unit calculates the second vector by multiplying a first vector including a plurality of time-varying coefficients that are not correlated with each other by a transformation matrix, thereby obtaining the correlated time-varying coefficient as the As a component of the second vector,
The product of the transformation matrix and its adjoint matrix is any one of additional notes 1 to 3, which is determined according to the given inter-polarization covariance matrix and is equal to the covariance matrix of the vertical polarization component and the horizontal polarization component at the receiving end. The antenna evaluation apparatus according to item.

(Appendix 5)
The antenna evaluation device according to appendix 4, wherein the plurality of time-varying coefficients are sine waves having a plurality of different periods or a plurality of different orthogonal code sequences.

(Appendix 6)
The antenna evaluation apparatus according to appendix 4 or 5, wherein the transformation matrix is a matrix obtained by eigenvalue decomposition or Cholesky decomposition of the covariance matrix.

(Appendix 7)
Generate a pair of correlated time-varying coefficients that are correlated with each other,
Generating a composite signal by multiplying the baseband signal by the correlation time-varying coefficient;
A test radio wave having a vertical polarization component and a horizontal polarization component of each combined signal generated by multiplying each pair of the correlation time-varying coefficients by a baseband signal is transmitted to the antenna to be evaluated,
In the generation of the correlation time-varying coefficient pair, a given inter-polarization co-variance that defines a covariance matrix of each propagation channel coefficient between the vertical polarization component and the horizontal polarization component at the transmission end and the reception end of the propagation path model. An antenna evaluation method for giving a correlation of a correlation amount between a vertical polarization component and a horizontal polarization component at the receiving end, which is determined by a dispersion matrix, to the pair of correlation time-varying coefficients.

1:00 antenna evaluation device 2 anechoic chamber 10 variant coefficient generator 20 synthesized signal generating unit 30 RF-signal generating unit 40 evaluation unit _{T 1v ~T nv, T 1v ~T} 4v vertically polarized wave component for transmitting antennas T _1h through T _nh, T _{1h to} T _4h Horizontally polarized wave transmitting antennas R ₁ and R2 Evaluation antenna

Claims (5)

A time-varying coefficient generating unit that generates a pair of correlated time-varying coefficients that are correlated with each other;
A composite signal generation unit that generates a composite signal by multiplying a baseband signal by the correlation time-varying coefficient;
A transmitting antenna that transmits test radio waves each having a composite signal generated by multiplying a pair of correlation time-varying coefficients to a baseband signal in a vertical polarization component and a horizontal polarization component to an antenna to be evaluated, respectively. Prepared,
The time-varying coefficient generation unit is a predetermined inter-polarization covariance matrix that defines a covariance matrix of each propagation channel coefficient between the vertical polarization component and the horizontal polarization component at the transmission end and the reception end of the propagation path model. An antenna evaluation apparatus that gives a correlation of a correlation amount between a vertical polarization component and a horizontal polarization component at the receiving end to the pair of correlation time-varying coefficients.   The antenna evaluation apparatus according to claim 1, wherein the time-varying coefficient generation unit gives a correlation based on a different polarization covariance matrix to the pair of correlated time-varying coefficients for each path included in the multipath. A plurality of transmitting antennas for transmitting the test radio waves from different directions;
The antenna evaluation apparatus according to claim 1, wherein the time-varying coefficient generation unit gives a correlation based on a common inter-polarization covariance matrix to the pair of time-varying signals among the plurality of transmission antennas. The time-varying coefficient generating unit calculates the second vector by multiplying a first vector including a plurality of time-varying coefficients that are not correlated with each other by a transformation matrix, thereby obtaining the correlated time-varying coefficient as the As a component of the second vector,
The product of the transformation matrix and its adjoint matrix is equal to a covariance matrix of a vertical polarization component and a horizontal polarization component at the receiving end, which is determined according to the given inter-polarization covariance matrix. The antenna evaluation device according to one item. Generate a pair of correlated time-varying coefficients that are correlated with each other,
Generating a composite signal by multiplying the baseband signal by the correlation time-varying coefficient;
A test radio wave having a vertical polarization component and a horizontal polarization component of each combined signal generated by multiplying each pair of the correlation time-varying coefficients by a baseband signal is transmitted to the antenna to be evaluated,
In the generation of the correlation time-varying coefficient pair, a given inter-polarization co-variance that defines a covariance matrix of each propagation channel coefficient between the vertical polarization component and the horizontal polarization component at the transmission end and the reception end of the propagation path model. An antenna evaluation method for giving a correlation of a correlation amount between a vertical polarization component and a horizontal polarization component at the receiving end, which is determined by a dispersion matrix, to the pair of correlation time-varying coefficients.

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