JPH1138058A - Measuring device for delay time of arrival angle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To measure the delay time of an incoming wave. SOLUTION: The inverse matrix Rex <-1> of an auto-correlation matrix of QNd order reception baseband signal vector is obtained (43) from a delay reception baseband signal group which is composed by severally delaying in order the reception baseband signal group x1 (i)-xQ(i) of terminals 251 -25Q obtained from Q pieces of antenna reception signals as much as a sampling period T3 through shift registers 411 -41Q, and in order to prescribe a restricting condition for keeping a delay time τ, the mean electric power of an incoming wave having an arrival angle θ fixed, a steering vector Aex H (θ, τ) expanded by τ, θ is obtained (44), and its complex conjugate transpose Aex H (θ, τ) is obtained (34), and Rex <-1> is multiplied by Aex H (θ, τ) (35), and an inner product between the product and Aex H (θ, τ) is obtained, and its reciprocal is obtained and outputted to a terminal 38 (37), and τ and θ of A (θ, τ) are altered in order and the output of the terminal 38 is plotted to obtain θ and τfor producing a peak.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an arrival angle delay time measuring device for measuring the arrival angle and delay time of an incoming wave in digital radio communication.

[0002]

2. Description of the Related Art In digital mobile communications, it is important to increase the number of frequency channels by effectively utilizing frequencies in order to meet rapidly increasing demand. Although it is necessary to shorten the frequency repetition distance in order to achieve spatially effective frequency utilization, the power of co-channel interference increases and transmission characteristics deteriorate significantly. Therefore, co-channel interference countermeasures are important. In recent years, introduction of an adaptive array, which is a type of interference canceller, has been studied.

[0003] The adaptive array adaptively controls the directivity of an antenna to remove an interference wave. In order to operate this adaptive array effectively, it is necessary to design parameters according to an actual moving propagation path. In particular, information on the angle of arrival of the arriving wave is important in design, and it is necessary to actually measure the angle of arrival. This measurement includes (i) MUSIC (Multiple Signal Classificati
on) Subspace-Based method such as algorithm, or (ii) MV
It is conceivable to use a beamforming method such as a DR (Minimum Variance Distortionless Response) algorithm for the estimation algorithm. However, since the Subspace-Based method performs eigenexpansion of a matrix, the amount of computation becomes enormous, and beamforming is relatively small It is preferable to apply the law.

In order to explain the angle of arrival estimation using the MVDR algorithm, the operation of an adaptive array using this algorithm will be described with reference to FIG. 3 (J. Capon, “Hi
gh-Resolution Frequency-Wavenumber Spectrum Analys
is ", Proc. IEEE, 57 (8), pp. 1408-1418, August 1969).
The number of antennas 11 is 11 _{1 to} 11 _Q (Q is a natural number of 2 or more), and the antennas 11 receive received waves. First, the antenna 11 ₁
Are amplified by the low-noise amplifier 12 and then branched by the hybrid 13. One signal that is sampled is passed through a low-pass filter 16 after the carrier signal generator 14 is multiplied by the multiplier 15 the carrier signal output by the A / D converter 17 every sampling period T _s, the digital signal Is converted to The sampling period T _s are equal to the symbol period T of the modulation unless otherwise specified. Another signal from the hybrid 13 is multiplied by a multiplier 19 with a carrier signal rotated by 90 degrees in a phase shifter 18, passed through a low-pass filter 21, sampled by an A / D converter 22, and converted into a digital signal. Is done. This operation is quasi-synchronous detection output of the A / D converter 17 and 22 correspond to the in-phase and quadrature components of the quasi-synchronized detection signal, and receives the combined two baseband signals x ₁ (i) . Thereafter, all the baseband signal phase component by the real part, the orthogonal component is expressed by complex notation to the imaginary part, i is an integer indicating the sampling value at time iT _s. The low-noise amplifier 12, hybrid 13, multipliers 15 and 19, phase shifter 18, low-pass filters 16 and 21, A / D converters 17 and 22
Constitutes a baseband receive signal generator 23 _1. Similarly, a received wave received from another antenna is input to a baseband reception signal generator and a reception baseband signal is output. Here, the baseband reception signal generator 2
3 ₁ ~ 23 _Q and carrier signal generator 14 corresponds to the receiving means.

[0005] Baseband received signal generator 23₁~ 23
_QBaseband signal group x from ₁(I) -x
_L(I) is the input terminal 25₁~ 25_QThrough
Each complex multiplier 26₁~ 26_QAnd the weighting coefficient w^*
₁~ W^* _LAre multiplied by
Output from the output terminal 28 as a composite signal y (i).
You. This process is a linear synthesis of the received baseband signal.
Antenna weight by adaptively controlling the weighting factor.
Interfering wave included in the received baseband signal by controlling the directivity
Remove components. The synthesized signal y (i) is expressed by the following equation
Original received baseband signal vector X (i) and Q-dimensional weight
When expressed using the weighting coefficient vector W, y (i) = W^HX (i) (1) W^H= [W₁ ^*w_Two ^*... w_Q ^*] (2) X^H(I) = [x₁ ^*(I) x_Two ^*(I) ... x_Q ^*(I)] (3) here^*Is the complex conjugate and^HIs the complex conjugate transpose
It is. The weighting coefficient estimation circuit 29
Signal group x₁(I) -x_L(I) and the composite signal y (i)
Weighting factor using MVDR algorithm as force
Is estimated and output.

[0006] The MVDR algorithm operates so as to extract only the arriving wave from φ, where φ is the angle of arrival of the desired wave. Specifically, the weighting coefficient is estimated such that the average power of the combined signal is minimized while the average power of the arriving wave at the arrival angle φ is kept constant. When the weighting coefficient is estimated in this manner, the arriving waves at other angles of arrival are removed, and the average power of the combined signal is proportional to the average power of the arriving waves at the angle of arrival φ when the noise signal power can be ignored.

Next, a constraint condition for keeping the average power of the arriving wave at the arrival angle φ constant will be described with reference to FIG. In this figure, it is assumed that the shape of the antenna is a linear array in which the antennas are arranged on a line at an interval d, and a plane wave having an arrival angle φ is arriving. Here, the interval d needs to be λ / 2 (λ: radio wave wavelength) or less in order to appropriately control the directivity of the array antenna. Incoming wave antenna 11 _2, a phase delay of 2πdcos φ / λ in the path difference d cos [phi relative to incoming waves of the antenna 11 _1. Similarly, the q-th (1 <
incoming wave q <Q) antenna 11 _q is, 2 [pi against incoming wave antenna 11 _{1 (q-1)} there is a phase delay of d cosφ / λ. Considering this phase delay and equation (1), the constraint condition for keeping the average power of the arriving wave at the arrival angle φ constant is W ^H A (φ) = 1 (constant) (4) A ^H (φ) = [a ^{_{1 * (φ) a 2 *}} (φ) ... a Q * (φ)] (5) a q (φ) = exp [-j2π (q-1) d cosφ / λ], 1 <q <Q (6 ). Here, A (φ) is a vector called a steering vector, and j is an imaginary unit.

The average power P (W) of the composite signal y (i) is given by the following equation (1): P (W) = W ^H RW (7) Here, R is an autocorrelation matrix of the Q-dimensional received baseband signal vector X (i), and R = <X (i) X ^H (i)> (8) Note that <> represents the ensemble average. W that minimizes equation (7) under the constraint condition of equation (4) is expressed as W
When _opt W _opt is ^{_{W opt = [A H (φ}} ) R -1 A (φ)] -1 R -1 A (φ) (9) and it is known to become (RTJr.Compton Author "Adapti
ve antennas "Chapter 6, Prentice Hall Publishing 1988
Year). Substituting equation (9) into equation (7) gives P _m (φ) = P (W _opt ) = [A ^H (φ) R ⁻¹ A (φ)] ⁻¹ (10)

P_m(Φ) = P (W_opt) Is a noise signal
When the power is negligible, the average power of the arriving wave at the angle of arrival φ
Proportional to the angle of arrival φ_mPlot (φ)
And find the peak to estimate the actual angle of arrival of the incoming wave
And the peak value is almost equal to the average power of the arriving wave.
Proportionally. Conventional MVDR algorithm
FIG. 4 shows the configuration of the arrival angle measuring device. Receive baseband signal
No. x₁(I) -x_Q(I) is the input terminal 25₁~ 25
_QEnter through. Inverse matrix corresponding to the inverse matrix operation means
The arithmetic circuit 31 receives the baseband signal group x₁(I) -x
_Q(I) to R^-1Is output. Steering vector
Steering vector generation circuit corresponding to the torque generation means
32 inputs the value θ of the arrival angle candidate from the input terminal 33
Based on equations (5) and (6), the steering vector A
(Θ) is obtained and output. The complex conjugate operation circuit 34
A complex of A (θ) with input of Aring vector A (θ)
Conjugate transpose A^H(Θ), and the matrix multiplication circuit 35 outputs R^-1
Is multiplied by A (θ) to obtain a vector R^-1Output A (θ)
You. The inner product operation circuit 36 calculates the multiplication result R^-1A (θ) and
Complex conjugate transpose A of the tearing vector ^H(Θ)
Product, A^H(Θ) R^-1A (θ) is obtained and output. Reciprocal performance
The arithmetic circuit 37 calculates the reciprocal of this inner product ｛A^H(Θ) R^-1A
(Θ)｝^-1And calculate the arriving wave corresponding to the arriving angle candidate θ.
Average power P_mOutput from the output terminal 38 as (θ).
You. Here, the complex conjugate operation circuit 34 and the matrix multiplication circuit 3
5, the inner product operation circuit 36 and the reciprocal operation circuit 37
It corresponds to an estimating means.

FIG. 6 shows a specific example in which P _m (θ) is plotted against the arrival angle candidate θ. Curve 61 is E _b / N ₀ = 3
0 dB, curve 62 is the noise power spectral density ratio E _b / N ₀ = 15dB, curve 63 is _{E b / N 0 = 0dB,} E b / N 0 is the signal energy per bit. here,
The number Q of antennas is 4, the antenna interval d is λ / 2, the modulation scheme is QPSK modulation, and two waves having the same average power at the arrival angles of 60 ° and 120 ° are assumed. When θ is 60 degrees and 120 degrees, P _m (θ) peaks, and the two peak values are almost equal. The average E _b / N ₀ is used as a parameter, and it can be seen that the peak becomes dull when the noise power is relatively high, that is, when the average E _b / N ₀ is small.

The inverse matrix operation means 31 in FIG. 4 obtains R ^-1 . The methods are (i) a method of calculating R and then an inverse matrix, and (ii) a method of directly obtaining R ^-1. is there. (I)
In the method (1), first, R defined by the equation (8) is obtained by replacing the ensemble average with the time average as shown below. At this time, it is assumed that sampling values from i = 1 to N have been obtained.

[0012] _{R = β N R N (11} ) R N = Σ i = 1 N λ Ni X (i) X H (i) (12) at ^{_{λ = 1 β N = N -1}} λ <1 in beta _N = [(1−λ ^N ) / (1−λ)] ⁻¹ (13) Here, exponentially weighted time average is performed, and the forgetting coefficient λ (0
<Λ < 1) was introduced. β _N is a normalization constant, which is a reciprocal of the actual observation time as shown in Expression (13). R ^-1 is obtained from Expression (11) as R ^-1 = β _N ^-1 R _N ^-1 (14).

The method (ii) is a method in which R _N ^-1 of the equation (14) is sequentially obtained by using the lemma of an inverse matrix.

[0014]

(Equation 1) Asking. However, the initial condition is R ₀ ^-1 = δ ^-1 I (16). Here, δ is a very small positive number, and I is a unit matrix. Once R _N ^-1 has been determined, R ^-1 is determined by substituting into equation (14). The advantage of this method is that the operation of the inverse matrix is not required and the amount of calculation is smaller than that of the method (i).

[0015]

When performing wideband transmission, an incoming wave having a delay time that cannot be ignored compared with the symbol period T arrives, causing intersymbol interference. It is necessary to introduce an adaptive equalizer. In designing an adaptive equalizer, information on the delay time is required, and it is necessary to actually measure the delay time in addition to the angle of arrival. However, the conventional angle-of-arrival measuring device of FIG. 4 separates and detects an incoming wave only based on the difference between the angles of arrival, and thus cannot measure the delay time of the incoming wave.

As described above, in the conventional angle-of-arrival measuring apparatus, when trying to apply to wideband transmission, the incoming wave is separated and detected only by the difference in the angle of arrival, so that the delay time of the incoming wave must be measured. There was a disadvantage that it could not be done. An object of the present invention is to provide an arrival angle delay time measuring device capable of measuring a delay time in addition to an arrival angle of an incoming wave.

[0017]

An arrival angle delay time measuring apparatus according to the present invention comprises: (1) receiving means for converting signals received from a plurality of antennas into a baseband; and (2) shifting a group of received baseband signals. Delay means for performing various delays by a register; (3) inverse matrix operation means for obtaining an inverse matrix of an autocorrelation matrix of a delayed reception baseband signal group; and (4) steering depending on arrival angle candidates and delay time candidates of arriving waves. Steering vector generating means for determining a vector,
(5) An average power estimating means for obtaining an average power of an incoming wave corresponding to the arrival angle candidate and the delay time candidate from the inverse matrix and the steering vector.

The inverse matrix calculating means divides the delayed reception baseband signal group based on the delay time or the receiving antenna number, and obtains an inverse matrix of a plurality of autocorrelation matrices corresponding to the divided delayed reception baseband signal group. Can be Along with this, the steering vector generation means:
In a configuration for outputting a plurality of steering vectors corresponding to the group of divided delayed reception baseband signals, the average power estimating means includes an average power of an incoming wave corresponding to an arrival angle candidate and a delay time candidate from a plurality of inverse matrices and a plurality of steering vectors. Is obtained. [Operation] The basic operation in the present invention is as follows. (1) The receiving means converts signals received from a plurality of antennas into a baseband and outputs the signals. (2) The delay means inputs the received baseband signal group to the shift register, and outputs the output signal of each shift stage of the shift register as a delayed received baseband signal group. (3) The inverse matrix operation means receives the delayed received baseband signal group as input, calculates and outputs an inverse matrix of the autocorrelation matrix.
(4) The steering vector generation means determines and outputs a steering vector from the arrival angle candidate and the delay time candidate of the incoming wave. (5) The average power estimating means multiplies the inverse matrix by the steering vector, finds the inner product of the result and the complex conjugate of the steering vector, and calculates the reciprocal of this inner product as the arrival angle candidate and the arrival time candidate corresponding to the delay time candidate. Output as the average power of the wave.

The inverse matrix calculating means divides the delayed reception baseband signal group based on the delay time or the reception antenna number, and calculates an inverse matrix of a plurality of autocorrelation matrices corresponding to the divided delayed reception baseband signal group. Can also be output. Along with this, the steering vector generation means determines and outputs a plurality of steering vectors corresponding to the group of divided delay reception baseband signals from the arrival angle candidate and delay time candidate of the arriving wave, and the average power estimation means For each band signal group, the inverse matrix is multiplied by the steering vector, the inner product of the vector of the multiplication result and the complex conjugate of the steering vector is obtained, and the reciprocal of the inner product is added to output as average power.

The difference from the prior art is that the average power of the arriving wave is obtained from the inverse matrix of the autocorrelation matrix of the delayed reception baseband signal group and the steering vector depending not only on the arrival angle candidate but also on the delay time candidate.

DETAILED DESCRIPTION OF THE INVENTION Embodiment 1 In the present invention, a transmission signal has a period T as shown in FIG.
This is a periodic signal S (t) of _F , and the periodic signal S (t) is assumed to be known on the receiving side. FIG. 1 shows the configuration of Embodiment 1 of the present invention.
(Claim 1). Received baseband signal groups x ₁ (i) to x _Q (i) are input from input terminals 25 _{1 to} 25 _Q ,
Shift registers 41 ₁ to 4 each corresponding to delay means
1 _Entered in _Q. Shift register 41 ₁ to 41 _Q is a cascade arrangement of delay elements 42 delay time equal to the sampling period T _s, the maximum delay time T _F -T _s and the number of delay elements such that N _D = T _F / T _s -1. Here, T _F / T _s is limited to a natural number. The shift registers 41 _{1 to} 41 _Q input the output signals to the inverse matrix operation circuit 43 as a delayed reception baseband signal group. The inverse matrix operation circuit 43 corresponds to an inverse matrix operation means, and instead of the Q-dimensional reception baseband signal vector X (i) defined by the equation (3), a QND _D- dimensional reception baseband signal vector X _ex defined by the following equation An inverse matrix R _ex ^-1 of the autocorrelation matrix of (k) is obtained.

[0022] ^{_{X ex H (k) = [}} X 1 H (k) X 2 H (k) ... X Q H (k)] (17) X q H (k) = [x q * (kT F / T _{^{s) x q * (kT F}} / T s -1) ... x q * (kT F / T s -N D +1)], 1 <q <Q (18) In addition, when calculating the inverse matrix, formula ( In the time average of 12), an integer k indicating an integer multiple of the period T _F is used instead of i. A space-time steering vector generation circuit 44 corresponding to a steering vector generation means inputs a delay time candidate value τ from an input terminal 45 and an arrival angle candidate value θ from an input terminal 33 to input a steering vector A _ex (θ, τ). Is output. This steering vector must define a constraint condition that the average power of the arriving wave with the delay time τ and the arrival angle θ is kept constant. Considering equation (17),
This A _ex (θ, τ) is calculated using the delay phase a _q (φ) and the transmission cycle signal vector S _p (t) in the above equation (5).
(Theta) to extend ^{_{the, A ex H (θ, τ}} ) = [a 1 * (θ) S p H (τ) a 2 * (φ) S p H (τ) ... a L * (φ) S ^{_{p H (τ)] (19}} ) S p H (τ) = [S * (N D T s -T s -τ) S * (N D T s -2T s -τ) ... S * (-τ) ] (20). Complex conjugate operation circuit 34 is the steering vector _{A ex (θ, τ) A} ex (θ, τ) as input the complex conjugate transpose A _ex ^H (θ, τ) of the outputs, the matrix multiplication circuit 35 R
_ex ^-1 is multiplied by A _ex (θ, τ) to obtain a vector R _ex ^-1 A
_ex (θ, τ) is output. Inner product calculating circuit 36 the inner product between the multiplication result _{^{R ex -1 A ex (θ,}} τ) and the complex conjugate transpose A _ex ^H steering vector _{(θ, τ), A ex} H (θ,
τ) _Obtain and output R _ex ^-1 A _ex (θ, τ). The reciprocal operation circuit 37 calculates the reciprocal of the inner product ｛A _ex ^H (θ, τ) R _ex ^-1 A
_ex (θ, τ)｝ ^{− 1} is calculated and output from the output terminal 38 as an average power P _m (θ, τ) of the arriving wave corresponding to the arrival angle candidate θ and the delay time τ. Here, the complex conjugate operation circuit 34, the matrix multiplication circuit 35, the inner product operation circuit 36, and the reciprocal operation circuit 37 constitute an average power estimation circuit 47, and correspond to an average power estimation means.

By plotting P _m (θ, τ) against the arrival angle candidate θ and the delay time candidate τ and searching for the peak value,
The arrival angle and delay time of an incoming wave can be estimated. As described above, since the inverse matrix of the autocorrelation matrix of the delayed reception baseband signal group is obtained and the steering vector depending not only on the arrival angle candidate but also on the delay time candidate is used, not only the arrival angle of the arrival wave but also the delay time Can be measured.

Here, the antenna is shown in FIG.
Although it was explained as a linear array like a circular circular
It can be easily applied to arrays. Also, sampling off
The sampling period T_s
May be less than the symbol period T of the modulation.Example 2 The configuration of the embodiment shown in FIG._DHas a large value
Sometimes the amount of calculation becomes enormous. Embodiment of the present invention shown in FIG.
The configuration of Example 2 is QN_DCalculation amount is suppressed even when is large.
(Claim 2). Input terminal 2
5₁~ 25_QFrom the received baseband signal group x₁(i) -x_Q1
(i) is input and the shift register
Star 41₁~ 41_QIs input to Shift register 41
₁~ 41 _QIs the delay time of the sampling period T_sbe equivalent to
This is a cascade configuration of delay elements, and the maximum delay time is T_F-T_s
The number of delay elements N_D= T_F/ T_s-1.
Here, T_F/ T_sIs limited to natural numbers. This
Shift register 41₁~ 41 _QDelays the output signal.
Input to the multi-inverse matrix operation circuit 51 as a baseband signal group.
Power. The multi inverse matrix operation circuit 51 is used as an inverse matrix operation means.
Equivalent, delay received baseband signal group based on delay time
Divided into baseband signals
And calculates and outputs an inverse matrix of a plurality of autocorrelation matrices.
Here, the delayed reception baseband signal group is divided into two.
You. QN determined by equation (17)_DDimensional reception baseband signal base
Kuturu X_exInstead of (k), QN_D1(1<N
_D1<N_D) -Dimensional received baseband signal vector X_ex1(k)
And Q (N_D-N_D1) Dimensional received baseband signal vector
Le X_ex2inverse matrix R of the autocorrelation matrix of (k)_ex ^-1And R_ex2 ^-1
Ask for.

X _exi ^H (k) = [X _1i ^H (k) X _2i ^H (k)... X _Qi ^H (k)], i = 1,2 (21) When calculating the inverse matrix, the time average of Expression (12) uses an integer k indicating an integer multiple of the period T _F instead of i. Space-time steering vector generator 44 _1, input terminal 4
5, the value of the delay time candidate τ and the value of the arrival angle candidate θ from the input terminal 33 are input, and the steering vector A _ex1 (θ, τ) corresponding to the QND _{D one-} dimensional reception baseband signal vector X _ex1 (k) is input. Is output. Similarly, space-time steering vector generator 44 _2, the value τ of the delay time candidates from the input terminal 45, by entering the value θ of arrival angle candidate from the input terminal _{33, Q (N D -N D1} ) dimension received base A steering vector A _ex2 (θ, τ) corresponding to the band signal vector X _ex2 (k) is obtained and output. These steering vectors must define a constraint that the average power of the arriving wave with the delay time τ and the angle of arrival θ be kept constant. Considering equation (22), this A _ex1 (θ,
τ) and A _ex2 (θ, τ) are A (θ) in the above equation (5).
A _exi ^H (θ) = [a ₁ ^* (θ) S _i ^H (τ) a ₂ ^* (φ) S _i ^H (τ)... A _Q ^* (φ) S _i ^H (τ) ], I = 1, 2 (23) Becomes Here, the space-time steering vector generation circuit 4
4 ₁ and 44 ₂ correspond to the steering vector generation means. The average power estimating circuits 47 ₁ and 47 _{2, as} in FIG. 1, respectively have inverse matrices R _ex1 ⁻¹ corresponding to X _ex1 (k).
And steering vector A _ex1 (θ, τ), X
_The inverse matrix R _ex2 ⁻¹ corresponding to _ex2 (k) and the steering vector A _ex2 (θ, τ) are input, and the reciprocal of the inner product ｛A
_ex1 ^H (θ, τ) R _{ex 1} ^-1 A _ex1 (θ, τ)｝ ^-1 and {A _ex2 ^H (θ, τ) R _ex2 ^-1 A _ex2 (θ, τ)｝ ^-1
Is calculated and output. The adder 52 adds the reciprocals of these inner products, and outputs the sum from the output terminal 38 as the average power of the incoming wave corresponding to the arrival angle candidate θ and the delay time τ. Here, the average power estimation circuits 47 ₁ and 47 ₂ and the adder 52 correspond to an average power estimation unit.

If the average power is plotted with respect to the arrival angle candidate θ and the delay time candidate τ and their peak values are searched for, the arrival angle and delay time of the arriving wave can be estimated. Since the amount of calculation here increases as a quadratic function of the dimensions of the matrix and the vector, by dividing the delayed reception baseband signal group based on the delay time and reducing the dimensions of the matrix and the vector, QN
Even when _D is a large value, the amount of calculation can be reduced as a whole.

Although the group of delayed reception baseband signals is divided on the basis of the delay time here, it can be easily divided on the basis of the antenna number.

[0028]

As described above, according to the present invention, the arriving wave is obtained from the inverse matrix of the auto-correlation matrix of the delayed reception baseband signal group and the steering vector depending not only on the arrival angle candidate but also on the delay time candidate. Since the average power is obtained, the delay time can be measured in addition to the angle of arrival of the incoming wave.

The co-channel interference cannot be ignored, and is effective when used in a radio system that performs high-speed transmission.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a functional configuration according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a functional configuration according to a second embodiment of the present invention.

FIG. 3 is a block diagram showing a functional configuration of a conventional adaptive array.

FIG. 4 is a functional configuration diagram of a conventional arrival angle measuring device.

FIG. 5 is a diagram showing a relationship between an antenna arrangement of an adaptive array and an incoming wave.

FIG. 6 is a diagram showing a plot example of arrival angle candidates and average power.

FIG. 7 is a diagram showing a signal configuration of a transmission signal.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI H03H 21/00 H03H 21/00

Claims (2)

[Claims] 1. A receiving means for converting received signals from a plurality of antennas into a baseband band and outputting a received baseband signal group, and inputting the received baseband signal group to a shift register, and each shift of the shift register Delay means for outputting the output signal of the stage as a delayed reception baseband signal group; inversion matrix operation means for receiving the delayed reception baseband signal group as input and calculating and outputting an inverse matrix of an autocorrelation matrix thereof; A steering vector generating means for determining and outputting a steering vector from the arrival angle candidate and the delay time candidate, and multiplying the inverse matrix by the steering vector to obtain an inner product of a vector of the multiplication result and a complex conjugate of the steering vector. The reciprocal of the inner product is defined as the average power of the arriving wave corresponding to the arrival angle candidate and the delay time candidate. AoA delay time measuring device, characterized in that it is composed of a mean power estimation means for outputting. 2. Receiving means for converting received signals from a plurality of antennas into a baseband band and outputting a received baseband signal group, inputting the received baseband signal group to a shift register, and shifting each of the shift registers. Delay means for outputting the output signal of the stage as a delayed reception baseband signal group; and a plurality of division means for dividing the delayed reception baseband signal group based on a delay time or a reception antenna number and corresponding to the divided delayed reception baseband signal group. An inverse matrix calculating means for calculating and outputting an inverse matrix of the autocorrelation matrix, and a steering for determining and outputting a plurality of steering vectors corresponding to the divided delayed reception baseband signal group from arrival angle candidates and delay time candidates of the arriving wave. Vector generating means, for each of the divided delay reception baseband signal groups, To obtain the inner product of the vector of the multiplication result and the complex conjugate of the steering vector, add the reciprocal of the inner product, and sum the sum to the average of the incoming waves corresponding to the arrival angle candidate and the delay time candidate. An arrival angle delay time measuring device, comprising: average power estimating means for outputting power.