JPH10229306A - Method and device for controlling adaptive array antenna - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve transmission speed by placing priority of at least part of processing in the calculation processing that adaptively calculates a weight coefficient of a signal related to each antenna element to be lower than the priority of other calculation processing for which high-speed signal processing is a requirement so as to reduce the calculation amount. SOLUTION: The priority of at least a part of processing in the calculation processing that adaptively calculates a weight coefficient of a signal related to each of antenna elements 30-1 to 30-m is placed lower than the priority of other calculation processing, for which high speed signal processing is a requirement. Then the calculation processing of a weight coefficient calculation circuit 32, consisting of a covariance matrix calculation section, an inverse matrix calculation section and a weight coefficient calculation section is conducted for a period CT5 which is longer than a sampling period TS, and the calculation processing by multipliers 33-1 to 33-m and an adder 34 is conducted for the sampling period TS. That is, since a plurality of processes whose output frequency of the calculation result differs are processed by a multi-task method, the calculation amount per the sampling period is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a method and an apparatus for controlling an adaptive array antenna used for various wireless communications.

[0002]

2. Description of the Related Art An adaptive array antenna has a strong directivity in a certain direction by multiplying a signal received by each antenna element by an appropriate weighting coefficient and combining the signals.
Conversely, it is an antenna capable of preventing sensitivity only to a signal arriving from a certain direction with zero sensitivity. This adaptive array antenna provides optimal weighting according to changes in the radio wave environment, performs optimal beamforming, realizes spatial filtering, and is used to avoid interference with other wireless communication systems. Is done.

In order for such an antenna to perform beam forming adapted to the radio wave environment, it is necessary to sequentially calculate and update weighting coefficients. Various methods have been conventionally proposed as adaptive control algorithms for the weight coefficient. As a method of implementing these control methods, a method of converting an analog signal into a digital signal and performing digital signal processing using a computer has been widely studied.

FIG. 1 shows a conventional phased array device disclosed in Japanese Patent Application Laid-Open No. 6-196921.

[0005] As shown in FIG.
Signals received by the array antenna 10 composed of 0-1 to 10-M are transmitted and received by the transmitting / receiving modules RM-1 to RM-M.
Is converted into a digital signal by the analog / digital converter 11 in the inside. The converted digital signals R _{1 to} R
_M multibeam are processed in forming circuit 12 corresponding to the beam power E ₁ to E _N, and the by the beam selecting circuit 13, a large beam SE ₁ to S of the power of which
E _N is selected and distributed by the in-phase distribution circuit 14.
This output is branched and then one of the branches, SEB ₁
～SEB _N is input to the adaptive control processor 15, the weighting factor W ₁ to _W-N is calculated by the digital signal processing. These weighting factors W _{1 to} W _N are sequentially updated,
The signals are supplied to variable gain amplifiers (multipliers) 16-1 to 16 _-N and multiplied by outputs SEA _{1 to} SEAN which are the other branches of the output of the in-phase distribution circuit 14. The outputs are combined by the in-phase combiner 17 to obtain a received baseband signal.

In transmission, the adaptive control processor 15
Phase amount DP ₁ to DP _M calculated by the phase calculating processor 18 in response to the output W ₁ to _W-N of is supplied to the phaser 19,
The transmission signals F _{1 to} F _{M obtained} by in-phase distribution of the transmission baseband signal by the in-phase distributor 20 are subjected to phase control to form a transmission beam.

[0007]

This type of control device for performing digital signal processing has the advantage of downsizing the device and the like, but has the problem that a heavy load is imposed on the computer for calculating the weighting factor, and the transmission speed is high. Therefore, its application range is limited. That is, since the operation speed of such an adaptive array antenna control device depends on the calculation speed of the computer to be driven, the signal transmission speed is also limited by the capability of the computer, so its application is limited. It will be lost.

For example, in the conventional example shown in FIG. 1, the processing cycle of each unit for performing digital signal processing is basically the same. That is, the processing priorities of the respective units are equal to each other. The transmission speed of such a digital signal processing system is determined by the sampling frequency when converting an analog signal to a digital signal from the relationship of the sampling theorem.
In the conventional example, since the processing priorities of the respective units are equal to each other, when performing an adaptive control in real time using this system, it is necessary to execute all calculation processes for each sample value and then obtain the next sample value. Becomes For this reason, it is impossible to realize a sampling period shorter than the time during which the entire calculation process is executed, and as a result, the transmission speed is defined by the processing speed of the computer.

On the other hand, the changing speed of the radio wave environment (for example, the moving speed of the signal wave source and the interference wave source, the moving speed of the mobile terminal)
Is generally slow enough for the sampling rate of digital signal processing. In consideration of this, the operation speed of the beam selecting means and the adaptive control processor in the conventional example described above, that is, the update speed of the weight coefficient does not need to be so high, and it is not necessary to update the weight at the sampling interval. Become. Therefore, performing all the processes with the same calculation priority (processing priority) gives an unnecessary calculation load to the digital signal processing unit, and as a result, lowers the sampling speed and lowers the transmission speed. .

As described above, according to the conventional method for calculating the weight coefficient of the adaptive array antenna, there is a problem that the sampling period is limited by the calculation load on the digital signal processing device, and as a result, the transmission speed is limited. .

Accordingly, it is an object of the present invention to provide an array antenna control method and apparatus which adapts to a higher transmission rate by more efficiently using the computing power of a computer which performs current limited digital signal processing. Is to do.

[0012]

According to the present invention, when control of an adaptive array antenna having a plurality of antenna elements is performed using digital signal processing, the weight coefficient of a signal relating to each antenna element is adaptively adjusted. There is provided an adaptive array antenna control method and apparatus in which the priority of at least a part of processing in a calculation processing unit for calculation is set lower than the priority of other calculation processing requiring high-speed signal processing.

Normally, in an environment to which an array antenna is applied, the geometric change speed of the radio wave environment such as the moving speed of a signal source and an interference source and a receiving point is very low as compared with the sampling speed of digital signal processing. is there. Therefore, the weight coefficient does not need to be updated at each sampling interval, and it is practically sufficient to repeat the holding and updating of the weight coefficient at a certain relatively long period. However, in the algorithm for asymptotically obtaining the weighting coefficient, the weighting coefficient is calculated for each sample value, but the target value is repeatedly held and updated at a constant relatively long cycle. As described above, in consideration of the speed of the change of the radio wave environment, by dividing and executing a portion of the array antenna control device that does not require a high-speed update of the calculation result, the calculation amount per sampling cycle is reduced, As a result, when processors having the same processing capacity are used, a higher transmission speed can be realized.

FIG. 2 is a diagram for explaining the basic principle of the present invention using two calculation processes having different update frequencies of the calculation shown on the time axis as an example. In this example, there are two calculation processes, a process 1 and a process 2, and the former has a higher priority than the latter, that is, the process 1 requires a faster update of the calculation result than the process 2. And

FIG. 1A shows a single task method which has been performed by the conventional signal processing, and all calculation processes are performed with the same priority. Therefore, the process 1 and the process 2 having higher temporal priority are calculated at the same update frequency, and the next sample value is obtained after performing all calculations at each sample time interval.
The only way to speed up the calculation is to improve the performance of the computer.

FIG. 1B shows a multitask method according to the basic principle of the present invention, in which the calculation process is divided into two tasks, task 1 and task 2. Process 1 which requires high-speed calculation completes the calculation within each sampling time interval, and process 2 which does not need to calculate the result at each sampling interval, the remaining time for calculating process 1 at each sampling interval. When the sampling interval time ends even during the calculation of the process 2, the calculation is interrupted, the next sample value is fetched, and the calculation of the process 1 is newly started. After the calculation of the process 1 is completed, the calculation of the process 2 which was halfway at the previous sampling time interval is restarted. As described above, by dividing and executing the calculation processing of the portion that does not require high-speed calculation result output, the calculation amount per sampling cycle is reduced, and as a result, when a processor having the same processing capacity is used. Transmission speed can be improved.

A method according to the invention comprises converting a plurality of analog signals received by an antenna element into digital signals,
In the case of including a process of adaptively calculating weighting factors corresponding to a plurality of antenna elements based on a plurality of converted digital signals, multiplying the calculated plurality of weighting factors by a plurality of digital signals, and then combining them. In addition, it is preferable that other calculation processing requiring high-speed processing includes at least conversion processing into a digital signal, multiplication processing, and synthesis processing.

It is preferable that other calculation processing requiring high-speed processing be completed within the sampling period of the conversion processing into a digital signal.

It is preferable that the calculation processing of the weight coefficient is completed in a cycle longer than the sampling cycle of the conversion processing into the digital signal.

An apparatus according to the present invention for controlling an adaptive array antenna having a plurality of antenna elements by using digital signal processing comprises an analog / digital conversion means for converting a plurality of analog signals received by the antenna elements into digital signals. Weight coefficient calculating means for adaptively calculating a weight coefficient corresponding to a plurality of antenna elements based on a plurality of converted digital signals; a plurality of weight coefficients output from the weight coefficient calculating means; A multiplying means for multiplying each of the plurality of digital signals; and a synthesizing means for synthesizing an output of the multiplying means. High-speed processing requires priority of at least a part of processing in the weight coefficient calculating means. Lower than the priority of the calculation processing of the analog / digital conversion means, the multiplication means and the synthesis means. It is preferable to.

In one embodiment of the present invention, the weight coefficient calculating means calculates a time average value of a covariance matrix of a plurality of sample values obtained from the analog / digital converting means based on a sampling period of the analog / digital converting means. A first calculating means for calculating in a long cycle, a second calculating means for calculating an inverse matrix of a covariance matrix obtained from the first calculating means in a cycle longer than a sampling cycle, and a second calculating means. A third calculating means for calculating a weighting factor of the array antenna from the inverse matrix of the obtained signal matrix, holding the weighting factor for a predetermined time longer than the sampling period, and updating the weighting factor at a predetermined time period; Contains.

In another embodiment of the present invention, the weighting factor calculating means includes a time average value of a covariance matrix of a plurality of sample values input from the analog / digital converting means for each sampling cycle of the analog / digital converting means. Calculating a signal wave arrival angle at a period longer than the sampling period, and calculating a weighting factor of the array antenna based on the signal wave arrival angle obtained by the first calculation unit. For a longer period of time,
A second calculating unit that holds the weighting coefficient and updates the weighting coefficient with a predetermined time as a cycle.

In this case, the first calculating means uses analog /
A third calculating means for calculating a time average value of a covariance matrix of a plurality of sample values obtained from the digital converting means at a cycle longer than a sampling cycle of the analog / digital converting means; and a third calculating means. Fourth calculating means for calculating the eigenvalues and eigenvectors of the covariance matrix at a period longer than the sampling period, and fifth calculation for obtaining the signal arrival angle from the eigenvalues and eigenvectors of the signal matrix obtained by the fourth calculating means. Means.

In still another embodiment of the present invention,
The weighting factor calculating means calculates a time average value of a covariance matrix of a plurality of sample values input from the analog / digital conversion means for each sampling cycle of the analog / digital conversion means, and determines a signal wave arrival angle in a cycle longer than the sampling cycle. A first calculating means which calculates and holds the weighting coefficient of the array antenna based on a signal wave arrival angle obtained by the first calculating means, a received signal fed back from the synthesizing means, and a sample value of each element output. , A second calculating means for updating at a sampling period.

[0025]

FIG. 3 is a block diagram schematically showing a control device of an adaptive array antenna according to an embodiment of the present invention. In the figure, reference numeral 30 denotes an array antenna having a plurality of antenna elements 30-1 to 30-m;
-1 to 31-m are analog / digital converters for converting analog outputs from the antenna elements 30-1 to 30-m into digital signals.
A digital converter 32, a weight coefficient calculating circuit for calculating a weight coefficient from the outputs of the analog / digital converters 31-1 to 31-m and the feedback output of the adder 34;
33-1 to 33-m are analog / digital converters 31
A multiplier for multiplying the outputs of −1 to 31-m by a weighting factor, 3
Reference numeral 4 denotes an adder for combining the outputs of the multipliers 33-1 to 33-m.

The analog outputs from the antenna elements 30-1 to 30-m are sampled at predetermined sampling periods T _S by analog / digital converters 31-1 to 31-m corresponding to each element, and are converted into digital signals. Is converted. The converted digital signal is multiplied by a corresponding weight coefficient in multipliers 33-1 to 33-m, and an adder 34
As a result, outputs corresponding to the respective antenna elements are combined. The results of these calculations must be calculated within a predetermined sampling period T _S in order to realize real-time adaptive control. The result is similarly fed back to a weighting factor calculation circuit 32 that outputs a weighting factor for each sampling period, a weighting factor is calculated, and a multiplier 33-
1-33-m. That is, the calculation processing that requires high-speed processing of the signal in the present invention is, in the present embodiment,
It corresponds to the calculation processing of the analog / digital converters 31-1 to 31-m, the multipliers 33-1 to 33-m, and the adder 34.

The weighting coefficient calculating circuit 32, the sampling period T _S is longer than the period CT _S (however, C is a constant greater than 1) and update calculates a weight coefficient, within this period CT _S, was calculated last time Output while retaining the value. It should be noted that T _S and _{C S S} shown in FIG. 3 indicate that signals are input and output in that cycle.

FIG. 4 is a block diagram showing an example of the configuration of the weight coefficient calculation circuit 32 in the embodiment of FIG. In this configuration example, the weight coefficient is obtained using the inverse matrix of the input signal matrix.

As a method of using an inverse matrix of a covariance matrix of an input signal, for example, an SMI (Sample Matrix)
x Inverse) algorithm. This control algorithm is described in, for example, "Multiple Wave Suppression in High-Speed Digital Land Mobile Communication Using an Adaptive Array Based on the SMI Method", Ogawa / Kawabata / Ito, Transactions of the Institute of Electronics, Information and Communication Engineers, B
-II Vol. J75-B-II No. 11 19
This is described in detail in November 1992.

According to the SMI algorithm, the optimum weight coefficient W _opt is expressed as follows. W _opt = R _xx ^-1 V _xr where R _xx and V _xr are trainings in which x _k (i) is a sampling value of the k-th antenna element at time i, and r (i) is placed at the head of each burst. Signal system, X
_{(I) = [x 1 (} i) x 2 (i) ··· x m (i)] T
Let ^T be the transpose, ^* be the complex conjugate, and E [] be the expected value (ensemble average), R _xx = E [X ^* (i) X ^T (i)] V _xr = E [X ^* (I) r (i)].

The plurality of antenna elements 30-1 to 30-1 shown in FIG.
After the input from 30-m is converted into a digital signal at a predetermined sampling period T _S by analog / digital converters 31-1 to 31-m shown in FIG. 4, each sample value x ₁ (i) to x _m (i) is input to the input signal covariance matrix calculator 32a, and the time average _Rxx and _{Vxr of the} covariance matrix are calculated. The time averages R _xx and V _xr of the covariance matrix calculated here are input to the inverse matrix calculation unit 32b. However, the output of the time average of the covariance matrix, the sampling period T _S is longer than the period CT _S (however, C is a constant greater than 1) takes place in. The inverse matrix calculator 32b takes in the time average value of the covariance matrix because the period C is equal to the output cycle of the calculation result of the covariance matrix calculator 32a.
And at the T _S, likewise calculates the inverse matrix R _xx ^-1 is also performed in a long period CT _S than the sampling period T _S. The correlation vector V _xr calculated by the covariance matrix calculation unit 32a and the inverse matrix R _xx ^-1 calculated by the inverse matrix calculation unit 32b are supplied to the weight coefficient calculation unit 32c, and the optimum weight coefficient W _opt is calculated. . The weight coefficient calculation unit 32c is an inverse matrix calculation unit 32
b, ie, the sampling period T _S
Updating the weight coefficients by performing calculations in a longer period CT _S, but supplied to the multiplier 33-1 to 33-m of the weighting factors, supplied with a period equal to the sampling period T _S. That is, in the period CT _S, holds the previous calculation results.

As described above, in the present embodiment, the calculation processing of the weight coefficient calculation circuit 32 composed of the covariance matrix calculation section 32a, the inverse matrix calculation section 32b and the weight coefficient calculation section 32c is longer than the sampling period T _S. performed in the period CT _S, it is performed calculation processing of the multipliers 33-1 to 33-m and the adder 34 with a sampling period T _S. That is, since a plurality of processes with different output frequencies of the calculation results are processed by multitasking, the amount of calculation per sampling cycle is reduced, and as a result, the transmission speed is improved when processors having the same processing capacity are used. It becomes possible.

FIG. 5 is a block diagram schematically showing a control device of an adaptive array antenna according to another embodiment of the present invention. In the figure, 51-1 to 51-m are analog / digital converters for converting analog outputs from antenna elements similar to the antenna elements 30-1 to 30-m in FIG. Reference numeral 52 denotes a weight coefficient calculation circuit for calculating a weight coefficient from the outputs of the analog / digital converters 51-1 to 51-m, and 53-1 to 53-m.
Is a multiplier for multiplying the output of the analog / digital converters 51-1 to 51-m by a weight coefficient, and 54 is a multiplier 53-1.
5 shows adders for combining outputs of .about.53-m. The weight coefficient calculation circuit 52 includes an arrival angle calculation unit 52a.
And a weight coefficient estimating unit 52b.

This embodiment is an example of a configuration in which an HA (Howells-Applebaum) algorithm, which is a control algorithm for controlling an array antenna composed of a plurality of antenna elements, is implemented using digital signal processing. In this HA algorithm, the arrival angle estimator sequentially estimates and updates the arrival angle, and uses an asymptotic method such as a steepest descent method or a direct solution method with an inverse matrix calculation.
The weight coefficient is supplied to a weight coefficient estimating unit that calculates the weight coefficient. However, the signal arrival angle of the desired wave is required as the target value.
This HA algorithm is described in, for example, "Progress and Future Prospects of Adaptive Antenna Theory", Ogawa and Kikuma, IEICE Transactions, B-II Vol. J75-B-II
No. 11 Detailed description in November 1992.

According to the HA algorithm, the optimum weight coefficient W _opt is expressed as follows. W _opt = R _xx ⁻¹ S ^* or W _opt = R _uu ⁻¹ S ^* where X _s (t) is a desired wave, X _i (t) is an interference wave, and X _n (t) is noise. If it is represented by a column vector, R _xx = E [{X _s (t) + X _i (t) + X _n (t)} ^*
_{{X s (t) + X} i (t) + X n (t)} T] R uu = E [{X i (t) + X n (t)} * {X i (t)
+ X _n (t)｝ ^T ], which are signal wave covariance matrices. Also,
S is said to steering vector indicates the relative phase of the received signals of the respective elements relative to the reference element, for example, in the case of equally spaced one-dimensional _{array, S = [s 1 s 2} ··· s m] T s n = 2 (m-1) πd sin θ / λ. Here, d is the element interval, λ is the wavelength of the received wave, and θ is the arrival angle. Further, ^T represents transpose, ^* represents complex conjugate, and E [] represents an expected value (ensemble average).

As described above, the HA algorithm includes a method of directly calculating an optimum weight by performing a calculation including such an inverse matrix and an asymptotic solution method using a steepest descent method. To do this, a direct solution is desirable. This is because the convergence speed is affected by the radio wave environment in the asymptotic method, but such a problem can be avoided by the direct solution. But,
Conventionally, the calculation load on the computer involved in the inverse matrix calculation has been a problem. However, as in the present invention, the priority of at least a part of the calculation processing for adaptively calculating the weight coefficient is determined by the high-speed processing. This can be solved by setting the priority lower than the required priority of other calculation processing.

In the embodiment shown in FIG. 5, inputs from a plurality of antenna elements are converted to analog / digital converters 51-.
From 1 to 51-m, the signal is converted into a digital signal at a predetermined sampling period T _S. These sample values x ₁
(I) to x _m (i) are input to the arrival angle calculator 52a and the weighting coefficient estimator 52b for each sampling period T _S. In the arrival angle calculator 52a, the sampling period T _S
, The arrival angle is calculated with a period CT _S longer than the sampling period T _S (where C is a constant greater than 1), and output at this period CT _S.

FIG. 6 shows an example of the structure of the arrival angle calculator 52a. In this example, the arrival angle estimation is performed using a plurality of outputs of an array antenna including a plurality of antenna elements. In general, in the control algorithm of the array antenna, there are many algorithms for adaptively controlling the weight coefficient using the arrival angle of a signal. For this reason, various algorithms for accurately estimating the angle of arrival of a signal have been proposed. Among them, there is MUSIC. The MUSIC algorithm, which eigenvector corresponding to the smallest eigenvalue of R _xx is an estimate of the signal arrival angles by utilizing the fact that perpendicular to the S ^*, for example, "High-Resolut
ion Technologies inSignal P
processing Antenna "; Ogaw
a, N .; Nikuma, IEICE Transact
ions on Commun. vol. E78-B
No. 11 Nov. 1995.

In FIG. 6, inputs from a plurality of antenna elements are analog-to-digital converters 51-1 to 51-.
m, the signal is converted into a digital signal at a predetermined sampling period T _S , and the sampled values x ₁ (i) to x _m
(I) is a covariance matrix calculation unit 5 for each sampling period T _S.
2a _1, and the time average value R _xx or R of the covariance matrix
_uu is calculated. Time average here is calculated covariance matrix is input to the eigenvalues and eigenvectors calculating section 52a _2. However, the output of the time average of the covariance matrix, the sampling period T _S is longer than the period CT _S (however, C is a constant greater than 1) takes place in. Also, capture the time-averaged value of the covariance matrix in the eigenvalue and eigenvector calculation section 52a ₂ is a the period equal CT _S to the output period of the covariance matrix calculating unit 52a ₁ of the calculation results are also eigenvalues and eigenvectors calculated Is also calculated at a period CT _S longer than the sampling period T _S. Calculated eigenvalues and eigenvectors eigenvalues and eigenvectors calculating section 52a ₂ is supplied to the DOA estimating unit (MUSIC algorithm) 52a _3, the arrival angle is output is calculated in a long period CT _S than the sampling period T _S You.
Arrival angle determined by the arrival angle estimation unit 52a ₃ is supplied to the weighting coefficient estimator 52 b, the optimal weight coefficient W _opt is calculated. The weighting coefficient estimating unit 52b
a period equal to the calculation period of a ₃ , that is, the sampling period T
_The weight coefficient is updated by performing the calculation at a cycle CT _S longer than _S , but the weight coefficient is supplied to the multipliers 53-1 to 53-m at a cycle equal to the sampling cycle T _S. That is, in the period CT _S, holds the previous calculation results.

The outputs of the multipliers 53-1 to 53-m are applied to an adder 54, and the outputs corresponding to the respective antenna elements are synthesized. Multipliers 53-1 to 53-m and adder 54
Is calculated to achieve real-time adaptive control.
The result must be calculated within a predetermined sampling period T _S. That is, in the present embodiment, the calculation processing that requires high-speed processing of signals in the present invention is performed by the analog / digital converters 51-1 to 51-m and the multipliers 53-1 to 53-1.
53-m and the calculation processing of the adder 54.

[0041] In this embodiment as described above, performs a calculation process consists weighting factor calculator circuit 52 from the incoming angle calculation unit 52a and the weight coefficient estimator 52b at the sampling period T _S is longer than the period CT _S, multiplication Vessels 53-1 to 53
−m, adder 54 and digital / analog converter 5
The calculation processing of No. 5 is performed at the sampling period T _S. That is, since a plurality of processes with different output frequencies of the calculation results are processed by multitasking, the amount of calculation per sampling cycle is reduced, and as a result, the transmission speed is improved when processors having the same processing capacity are used. It becomes possible.

FIG. 7 is a block diagram schematically showing a control device of an adaptive array antenna according to still another embodiment of the present invention. 3, 71-1 to 71-m are not shown, but the antenna elements 30-1 to 30-m of FIG.
An analog / digital converter 72 for converting an analog output from an antenna element into a digital signal in the same manner as described above, and a weight coefficient 72 is calculated from the outputs of the analog / digital converters 71-1 to 71-m and the feedback output of the adder 74. Weight coefficient calculation circuits, 73-1 to 73-m are multipliers for multiplying the outputs of analog / digital converters 71-1 to 71-m by weight coefficients, and 74 is multipliers 73-1 to 73-m.
An adder for combining the outputs of m is shown. The weight coefficient calculation circuit 72 includes an arrival angle calculation section 72a and a weight coefficient estimation section 72b.

As in the embodiment of FIG. 5, the present embodiment is an example of a configuration in which an HA algorithm, which is a control algorithm for controlling an array antenna composed of a plurality of antenna elements, is implemented using digital signal processing. However, in the present embodiment, the weight coefficients are converged in an asymptotic manner via the HA loop. For this reason, the arrival angle calculator 72a sets the cycle C longer than the sampling cycle T _S.
T _S (however, C is a constant greater than 1), but calculates and outputs the arrival angle in this period CT _S, weighting coefficient estimator 72
In b, the weight coefficient is calculated and updated at the sampling period T _S , and the updated value is output. Other configurations, algorithms, operational effects, and the like of this embodiment are exactly the same as those of the embodiment of FIG. In the present embodiment, the calculation processing that requires high-speed processing of signals in the present invention is performed by analog / digital converters 71-1 to 71-m and multipliers 73-1 to 73-.
m, the calculation processing of the adder 74 and the weight coefficient estimation unit 72b.

The embodiments described above all show the present invention by way of example and not by way of limitation, and the present invention can be embodied in other various modifications and alterations. Therefore, the scope of the present invention is defined only by the appended claims and their equivalents.

[0045]

As described in detail above, in the present invention,
When performing the control of the adaptive array antenna having a plurality of antenna elements using digital signal processing, the priority of at least a part of the processing in the calculation processing of adaptively calculating the weight coefficient of the signal for each antenna element, The priority is set lower than the priority of other calculation processing requiring high-speed signal processing. In this way, by dividing and executing the calculation processing of the portion that does not require high-speed calculation result output, the calculation amount per sampling cycle is reduced, and as a result,
When processors having the same processing capacity are used, the transmission speed can be improved. That is, the present invention can be applied to higher transmission speeds by more efficiently using the calculation capability of the currently limited digital signal processing mechanism.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a conventional phased array device.

FIG. 2 is a diagram for explaining a basic principle of the present invention.

FIG. 3 is a block diagram schematically showing a control device of an adaptive array antenna according to an embodiment of the present invention.

FIG. 4 is a block diagram illustrating a configuration example of a weight coefficient calculation circuit in the embodiment of FIG. 3;

FIG. 5 is a block diagram schematically showing a control device of an adaptive array antenna according to another embodiment of the present invention.

FIG. 6 is a block diagram illustrating a configuration example of an arrival angle calculator in the embodiment of FIG. 5;

FIG. 7 is a block diagram schematically showing a control device of an adaptive array antenna according to still another embodiment of the present invention.

[Explanation of symbols]

30 array antenna 30-1 to 30-m antenna element 31-1 to 31-m, 51-1 to 51-m, 71-1
71-m analog / digital converter 32, 52, 72 weight coefficient calculation circuit 32a, 52a ₁ covariance matrix calculation section 32b, 72b inverse matrix calculation section 32c weight coefficient calculation section 33-1 to 33-m, 53-1 53-m multipliers 34, 54, 74 Adders 52a, 72a Arrival angle calculator 52a ₂ Eigenvalue and eigenvector calculator 52a ₃ Signal arrival angle estimator 52b Weight coefficient estimator

Claims (10)

[Claims] 1. A method for controlling an adaptive array antenna having a plurality of antenna elements using digital signal processing, wherein at least one of the calculation processes for adaptively calculating a weight coefficient of a signal related to each antenna element is performed. A method of controlling an adaptive array antenna, wherein the priority of the processing of the unit is set lower than the priority of another calculation processing requiring high-speed processing of the signal. 2. Converting a plurality of analog signals received by the antenna element into digital signals, adaptively calculating weighting factors corresponding to the plurality of antenna elements based on the converted plurality of digital signals, A method comprising a process of multiplying each of the calculated plurality of weighting coefficients and the plurality of digital signals and then synthesizing each of the plurality of weighted coefficients, wherein another calculation process requiring the high-speed processing is a conversion process to the digital signal, The method of claim 1, comprising at least a multiplication operation and the combining operation. 3. The method according to claim 2, wherein the other calculation processing requiring the high-speed processing is completed within a sampling period of the conversion processing into the digital signal. 4. The method according to claim 2, wherein the calculation process of the weight coefficient is completed in a cycle longer than a sampling cycle of the conversion process into the digital signal. 5. An apparatus for controlling an adaptive array antenna having a plurality of antenna elements by using digital signal processing, wherein at least one of the calculation processing for adaptively calculating a weight coefficient of a signal relating to each of the antenna elements is performed. A control device for an adaptive array antenna, wherein the priority of the processing of the unit is set lower than the priority of another calculation processing requiring high-speed processing of the signal. 6. An apparatus for controlling an adaptive array antenna having a plurality of antenna elements by using digital signal processing, wherein the plurality of analog signals received by the antenna elements are converted into digital signals. Means, weight coefficient calculating means for adaptively calculating weight coefficients corresponding to the plurality of antenna elements based on the converted plurality of digital signals, a plurality of weight coefficients output from the weight coefficient calculating means, A multiplying means for multiplying each of the plurality of digital signals obtained from the converting means; and a synthesizing means for synthesizing an output of the multiplying means. Calculation of the analog / digital converting means, the multiplying means and the synthesizing means for which high-speed processing is required. A control device for an adaptive array antenna, wherein the control is set lower than the processing priority. 7. The weight coefficient calculating means calculates a time average value of a covariance matrix of a plurality of sample values obtained from the analog / digital converting means at a cycle longer than a sampling cycle of the analog / digital converting means. First
Calculating means, a second calculating means for calculating an inverse matrix of the covariance matrix obtained from the first calculating means at a cycle longer than the sampling cycle, and a signal obtained by the second calculating means. A third calculating means for calculating a weighting factor of the array antenna by using an inverse matrix of the matrix, holding the weighting factor for a predetermined time longer than the sampling period, and updating the weighting factor with the predetermined time as a period 7. The apparatus of claim 6, comprising: 8. The weighting coefficient calculating means obtains a time average value of a covariance matrix of a plurality of sample values input from the analog / digital conversion means for each sampling cycle of the analog / digital conversion means, and obtains a signal wave. First calculating means for calculating the arrival angle at a period longer than the sampling period, and calculating a weighting factor of the array antenna based on the signal wave arrival angle obtained by the first calculating unit; 7. The apparatus according to claim 6, further comprising: a second calculating unit that holds the weighting factor for a predetermined time and updates the weighting factor with the predetermined time as a cycle. 9. The method according to claim 8, wherein the first calculating means calculates the analog /
A third calculating means for calculating a time average value of a covariance matrix of a plurality of sample values obtained from the digital converting means in a cycle longer than a sampling cycle of the analog / digital converting means; and Fourth calculating means for calculating the eigenvalues and eigenvectors of the obtained covariance matrix at a period longer than the sampling period, and obtaining the signal arrival angle from the eigenvalues and eigenvectors of the signal matrix obtained by the fourth calculating means 9. Apparatus according to claim 8, including fifth calculating means. 10. The signal weighting means according to claim 1, wherein said weight coefficient calculating means obtains a time average value of a covariance matrix of a plurality of sample values inputted from said analog / digital conversion means at each sampling cycle of said analog / digital conversion means. First calculating means for calculating and holding the angle of arrival at a period longer than the sampling period; a signal wave arrival angle obtained by the first calculating means, a received signal fed back from the synthesizing means, and an output of each element; 7. The apparatus according to claim 6, further comprising: second calculating means for calculating and updating a weight coefficient of the array antenna at the sampling period from the sample value.