JP2002368521A - Adaptive array antenna - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an adaptive array by which an interference wave from an object to be interfered such as a microwave oven is reduced and communication is performed even while the object to be interfered is working. SOLUTION: A weight for suppressing the interference wave of the object to be interfered is calculated based on reception data which is obtained by a prescribed timing in one cycle of the working power source of the object to be interfered in a state where the object to be interfered such as the microwave oven is working and, then, the weight is stored. After this, the stored weight is set by the timing in the power source cycle.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adaptive array antenna for reducing interference caused by an electromagnetic wave generated by an interfered object when performing wireless communication.

[0002]

2. Description of the Related Art Conventionally, when performing wireless communication such as a wireless LAN in an environment using a microwave oven, particularly, 2.4 GHz
In the band, the frequency band of the radiated noise generated from the microwave oven overlaps with the frequency band of communication, so that a problem that communication is hindered has occurred.

FIG. 18 shows a configuration of a conventional 2.4 GHz band wireless LAN system. A base station 901 is connected to a backbone 906 through which various information is transmitted, and signals are transmitted between the base station 901 and the terminal 902. Base station 901
Since the antenna pattern 904 used by the terminal 902 covers a wide range, a signal from the terminal 902 can be received regardless of the position of the terminal 902.

However, there is a microwave oven 903 in the communication service area of the base station 901. When the microwave oven 903 operates, the radiated waves of the microwave oven 903 cause interference, and the microwave oven 903 operates.
There is a problem that the signal from the terminal 902 cannot be received by the base station 901 while the 03 is operating.

[0005]

As described above, the conventional adaptive array antenna has a problem in that it is affected by an interference object when used in a frequency band that is subject to interference by electromagnetic waves from a microwave oven or the like.

[0006] In order to solve such a problem, the present invention uses an adaptive array antenna which is less affected by interference from an object to be interfered, thereby performing wireless communication in which interference is further reduced and communication quality is prevented from deteriorating. The purpose is to:

[0007]

In order to achieve the above object, an adaptive array antenna according to the present invention uses the interference object based on reception data acquired at a predetermined timing in one cycle of an operation power supply of the interference object. And calculating and storing a weight for reducing the interference wave from the power supply, and setting the stored weight at a predetermined timing when the reception data is acquired in a subsequent power supply cycle.

Also, a plurality of antenna elements, a plurality of weighters for respectively weighting the received signals received by the plurality of antenna elements, and a combiner for combining the received signals weighted by the plurality of weighters, A timing control device that outputs a data acquisition trigger at a predetermined timing for each power supply cycle of the interfered object; and at least one when the timing control device outputs the data acquisition trigger.
A weight control device that obtains reception data received by the two antenna elements, calculates a weight for reducing the interference wave from the interfered object for each predetermined data sample, and sets the weight for the plurality of weighters. It is assumed that.

Further, the object to be interfered is a microwave oven.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) FIG. 1 shows the principle of a 2.4 GHz band wireless LAN system to which a first embodiment of the present invention is applied.

As shown in FIG. 1, in the wireless LAN system, a base station 2 is connected to a backbone 6 through which various information is transmitted, and signals are transmitted between the base station 2 and the terminal 3. Have been done. Further, transmission and reception of signals between the base station 2 and the terminal 3 are performed via the adaptive array antenna 1.

When the microwave oven 4 operates, the adaptive array antenna 1 installed in the base station 2 forms a beam 5 that directs a directional null in the direction of the microwave oven 4.
The base station 2 can receive the signal from the terminal 3 without error even during the operation of the microwave oven without being affected by the interference wave from the microwave oven 4.

FIG. 2 shows the configuration of the adaptive array antenna according to the first embodiment.

The received signals from the terminals received by the antenna elements 111 to 114 are amplified by amplifiers 121 to 124 and a frequency converter 13.
The weights are passed through 1-134 and weighted by weighters 121-124, respectively. The weighted received signals are combined by the combiner 15 and transmitted to the base station 2. The power level of the combined reception signal is detected by the reception power detection device 18.

The timing controller 16 first outputs a data acquisition trigger at a predetermined timing while the microwave oven is operating. The weight control device 17 acquires the reception level data detected by the reception power detection device 18 at the timing of the data acquisition trigger, and calculates the weight so that the beam is directed to the terminal and the null is directed to the microwave oven. And set in the weighters 141 to 144. Further, after setting the weight, the output of the data acquisition trigger from the timing control device 16 is stopped, and the adaptive antenna operates by adding the set weight.

The weight calculation is described in Japanese Patent Application No. 2000-132544 "Adaptive Antenna", as described later, whereby nulls can be directed to interference waves to suppress them.

Next, the operation of this embodiment will be described. The interference wave of the microwave oven is 1 in one cycle of the operation power supply of the microwave oven.
Times, a short time, which occurs in a cycle equal to the power supply cycle. That is, as shown in FIG. 3, time is plotted on the horizontal axis and signal level is plotted on the vertical axis, and the time is divided for each power supply cycle ((A) to (D)), and one cycle of the power supply cycle is divided into a plurality of times. Then, it can be shown that the interference waves of the microwave oven A and the microwave oven B are generated every period.

Therefore, in the present embodiment, data of a predetermined section A (d1 to d2) of one cycle (A) (1 to d1 to d2 to n) of the power supply cycle is sampled and detected by the reception power detection device. The reception level data is acquired, and a weight is calculated for each data sample in the section A (d1 to d2).

Subsequent periods ((B), (C), (D))
With regard to the above, the interference wave of the microwave oven can be suppressed by adding the above-mentioned weight.

Next, the timing control device 16 will be described. The power supply synchronizer 161 outputs a counter value (1 to d1 to d2 to n) initialized for each power supply cycle. The timing storage device 162 stores a counter value (d1 to d2) corresponding to a predetermined data acquisition timing. The first trigger 163 outputs a data acquisition trigger when the counter value output from the power synchronization device 161 is equal to the counter value (d1 to d2) stored in the timing storage device 162. In addition, the power synchronizer 16
The output of 1 is input to the power supply synchronization counter 1631. The power supply synchronization counter 1631 outputs a control signal for stopping the operation of the first trigger device 163 when the counter output by the power supply synchronization device 161 makes one circuit.

Next, the power supply synchronization device 161 will be described.
The clock generator 1611 generates a clock at a predetermined cycle. The power cycle storage device 1612 stores the number of clocks (n) corresponding to the power cycle.

For example, the number of clocks (n) corresponding to the power supply cycle may be a value obtained by dividing the power supply cycle by the clock cycle and rounding the value to one decimal place.

The clock counter 1613 counts clocks generated by the clock generator 1611 and initializes the counter for each clock number (n) stored in the power cycle storage device 1612.

With such a configuration, the timing control device
No. 16 can output a data acquisition trigger at a predetermined timing every power cycle of the microwave oven.

Next, the operation procedure of the adaptive array antenna having the above configuration is shown in FIG.

First, an initial control signal from a control unit (not shown) for controlling the adaptive array antenna is supplied to the weight control device 19 and the timing control device 16,
The weights set in the weighters 141 to 144 and the counter of the power supply synchronizer 161 are initialized (S1).

Next, after confirming the operation of the timing controller 16 (S2), a data acquisition trigger is generated from the timing controller 16 (S3). The received power data detected by the received power detection device 18 in response to the data acquisition trigger is input to the weight control device 161 (S4).

Next, after confirming the input of the received power data of the predetermined sample to the weight control device 17 (S5), the weight for suppressing the range interference wave is calculated by the weight control device 17 and set in the weighters 141 to 144. I do. (S6) Also,
FIG. 5 shows an operation procedure of the timing control device 161. First, an initial control signal from a control unit (not shown) for controlling the adaptive array antenna is transmitted to the timing control device 161.
To initialize the counter of the power synchronizer 161 to 0 (S1).

Next, the output of the power synchronizer 161 is input to the first trigger device 163 and the power cycle counter 1631 (S
2).

Next, the power supply cycle counter 1631 makes one round of the clock counter, that is, determines whether the clock value of the power supply synchronization device 161 is maximum, and outputs a control signal for stopping the operation of the first trigger device 163 if the clock value is maximum. The operation ends (S3).

Further, the output of the power supply synchronization device 161 is compared with the counter value stored in the timing storage device 162 (S
4) When the counter values are equal, the first trigger 163 outputs a data acquisition trigger to the weight control device 17 (S).
5).

The operation procedure of the power supply synchronization device 161 is shown in FIG.
Shown in First, an initial control signal from a control unit (not shown) for controlling the adaptive array antenna is supplied to the timing control device 16, and the clock counter is initialized to 0 (S1).

Next, the clock from the clock generator 1611 is input to the clock counter 1613 (S2), and the clock counter 1613 starts counting the clock. Next, the counter value of the clock counter 1613 and the power cycle storage device 1612
Is compared with the clock value corresponding to the power supply synchronization stored in (S3). If these values are equal, the process returns to S1, and if they are not equal, the count of the clock counter 1613 is increased by one (S4). It returns to (S2) again.

As described above, the weight for reducing the interference wave of a plurality of microwave ovens is calculated in advance, and the interference wave can be reduced by using the same weight when the microwave oven is operated after the start of the microwave oven. The characteristic that the occurrence timing of interference between microwave ovens is constant irrespective of the temperature is utilized. Therefore, the weight can be calculated in advance off-line, so that the signal processing unit required for the weight calculation can be operated at a low speed, and the power consumption by the weight calculation can be suppressed low.

Next, the aforementioned Japanese Patent Application No. 2000-132 is disclosed.
A description will be given of the case where null is directed to the interference wave shown in 544 “Adaptive Antenna”.

FIG. 7 is a configuration diagram of the adaptive array antenna. In FIG. 7, 111 to 114 are antenna elements,
Reference numerals 121 to 124 denote amplifiers for amplifying the reception signals received by the antenna elements 111 to 114, respectively, and reference numerals 141 to 144 respectively set the amplified reception signals by a weight control device (phase shift amount control means) 17 described later. A variable phase shifter that performs phase control according to the amount of phase shift, 15 is a combiner that combines the phase-controlled received signals, and 16 is a demodulator that is provided in the base station and demodulates the received signal combined by the combiner. , A signal strength detecting means (reception power detecting device) for detecting the strength of the received signal synthesized by the synthesizer 15, and 17 a phase shift amount newly set based on the strength of the detected received signal. , And sets the calculated phase shift amounts to the variable phase shifters 141 to 144, respectively.
Operation control means for controlling the operation according to the output of the trigger.

341 to 34n store the phase shift amounts Φ1 (k) to Φn (k) (n is the number of antenna elements and k is the number of updates of the phase shift amounts) set in the variable phase shifters 141 to 144, respectively. The first phase shift amount storage means 351 to 35n store the stored phase amount Φ1
Second phase shift amount storage means for calculating and storing phase shift amounts Φ1 ′ (k) to Φn ′ (k) in which (k) to Φn (k) are respectively increased by 90 degrees. 1 phase shift amount storage means 341
.Phi.1 (k) to .PHI.n (k) stored by .about.34n.
Phase shift amounts Φ1 ″ (k) to Φ, each of which is reduced by 90 degrees
a third phase shift amount storage means for calculating and storing n ″ (k);
The shifts 371 to 37n are stored in any one of the first phase shift amount storage means 341 to 34n, the second phase shift amount storage means 351 to 35n, or the third phase shift amount storage means 361 to 36n. Phase shift amount setting means for setting the phase amounts to the variable phase shifters 141 to 144, 311
Are Φ1 (k), Φ2 (k),
..., Φi-1 (k), Φi '(k), Φi + 1
(K),..., Φn (k) (1 ≦ i ≦ n) is set, and the first signal strength storage for storing the strength Pi ′ of the received signal detected by the signal strength detecting means 18. Means, 3
21 denotes variable phase shifters 141 to 144 respectively having Φ1 (k) and Φ2
(K), ..., Φi-1 (k), Φi "(k), Φi
+1 (k),..., Φn (k) are set,
Received signal strength P detected by signal strength detecting means 18
The second signal strength storage means 331 for storing i ″ increases Φi (k) stored in the i-th phase shift amount storage means by a value proportional to the difference between Pi ′ and Pi ″. A new phase shift amount Φi (k + 1) is calculated and input to the i-th phase shift amount storage means.
1 (0) to φn (0) are stored, and the phase shift amount control means 17 is stored.
When they operate for the first time, they Φ1 (0) to Φn
(0) is Φ1 of each of the first phase shift amount storage means 341 to 34n.
(K) to Φn (k) as initial value storage means.

The operation of the adaptive array antenna configured as described above will be described. FIG. 8 is a flowchart showing the operation of the adaptive array antenna. First,
Phase shift amount Φ1 (0) stored by initial value storage means 381
Is input to the first phase shift amount storage means 341. Based on this, Φ1 (0) is stored in Φ1 (k) by the phase shift amount storage means 341 as follows (S1).

Φ ₁ (k) = Φ ₁ (0) Subsequently, the phase shift amount Φ ₁ (k) stored by the first phase shift amount storage means 341 is input to the second phase shift amount storage means 351. You. Based on this, Φ1 ′ (k) is obtained as follows by the second phase shift amount storage means 341 (S2).

Φ ₁ ′ (k) = Φ ₁ (k) +90 Subsequently, the phase shift amount Φ ₁ (k) stored by the first phase shift amount storage unit 341 is stored in the third phase shift amount storage unit 361. Is entered. Based on this, Φ1 ″ (k) is obtained as follows by the third phase shift amount storage means 361 (S3).

Φ ₁ ″ (k) = Φ ₁ (k) −90 S2 to S3 may be processed in the order of S3 → S2.
Subsequently, the phase shift amount Φ1 (k) stored by the first phase shift amount storage unit 341 is input to the phase shift amount setting unit 371. This phase shift amount is set in the variable phase shifter 141 by the phase shift amount setting means 371 (S4). Subsequently, initial value storage means 382 to 38
Similarly, the phase shift amounts Φ2 (0) to Φn (0) stored by n are set in the variable phase shifters 142 to 144 by the phase shift amount setting means 372 to 37n.

Initial value of phase shift amount Φ1 (0) to Φn (0)
May be set to, for example, a phase shift amount for in-phase synthesis of a desired wave. Next, in S5, it is determined whether i is equal to or more than n,
If i is not equal to or more than n, the processing from S1 to S4 is repeated, and if i is equal to or more than n, k = 1 is set in S6.

At time t, the received signals received by the antenna elements 111 to 114 and amplified by the amplifiers 121 to 124 are defined as S1 (t) to Sn (t). These signals are phase-controlled by the variable phase shifters 141 to 144 and are synthesized by the synthesizer 15. Assuming that the phase shift amounts set in the variable phase shifters 141 to 144 are Φ1 (k) to Φn (k), the combined received signal y (t) is

[0044]

(Equation 1)

## EQU5 ## This combined received signal y
(T) is input to the signal strength detecting means 18. Based on this, the strength P of the received signal detected by the signal strength detecting means 18 is

[0046]

(Equation 2)

## EQU5 ## Here, E [•]: expected value operation, *: complex conjugate. The expected value calculation is actually replaced by the time average calculation. This is the signal strength detection means 18.
Can be obtained by setting the time constant of to a sufficiently large value.

The characteristic of this adaptive antenna is that a partial differential coefficient of the signal strength of the received signal detected by the signal strength detecting means 18 with respect to the phase shift amount set in each of the variable phase shifters 141 to 144 is represented by a signal strength. The point is that it can be obtained using only the signal strength of the received signal detected by the detecting means 18. The phase shift amount control is performed based on this partial differential coefficient. The phase shift amounts set in the variable phase shifters 141 to 144 are calculated by the phase shift amount control means 17 one by one. Here, a method of updating the phase shift amount of the variable phase shifter 141 will be described.

The phase shift amount Φ′1 (t) stored by the second phase shift amount storage unit 351 is input to the phase shift amount setting unit 371. This phase shift amount is set in the variable phase shifter 41 by the phase shift amount setting means 371 (S8). In this state, the received signal strength P1 'detected by the signal strength detecting means 18 is input to the first signal strength storing means 311 (S9). Subsequently, the phase shift amount Φ ″ 1 (t) stored by the third phase shift amount storage unit 361 is input to the phase shift amount setting unit 371. The phase shift amount is variable by the phase shift amount setting unit 371. The setting is made in the phase shifter 41 (S10) In this setting state, the received signal strength P1 "detected by the signal strength detecting means 18 is inputted to the second signal strength storing means 321 (S11). S8 ~
S11 may be processed in the order of S10 → S11 → S8 → S9.

Subsequently, the received signal strength P 1 ′ stored in the first signal strength storage means 311, the received signal strength P 1 stored in the second signal strength storage means 321, and the first phase shift amount storage Phase shift amount Φ1 (k) stored by means 341
Is input to the phase shift amount calculating means 331. Based on these inputs, a new phase shift amount Φ1 (k
+1) is calculated as follows (S12).

Φ ₁ (k + 1) = Φ ₁ (k) + α (P ₁ ′ −P ₁ ″) where α is a real number.

Subsequently, the new phase shift amount Φ1 (k + 1) calculated by the phase shift amount calculating means 331 is stored in the first phase shift amount storing means.
Entered in 341. Based on this, the first phase shift amount storage means 341 converts Φ1 (k + 1) into Φ1 (k) as follows.
(S13).

Φ ₁ (k) = Φ ₁ (k + 1) Subsequently, the phase shift amount Φ ₁ (k) stored by the first phase shift amount storage means 341 is input to the second phase shift amount storage means 351. You. Based on this, Φ1 ′ (k) is obtained by the second phase shift amount storage means 351 as follows (S14).

Φ ₁ ′ (k) = Φ ₁ (k) +90 Subsequently, the phase shift amount Φ ₁ (k) stored by the first phase shift amount storage unit 341 is stored in the third phase shift amount storage unit 361. Is entered. Based on this, Φ1 ″ (k) is obtained as follows by the third phase shift amount storage unit 361 (S15).

Φ ₁ ″ (k) = Φ ₁ (k) −90 S14 to S15 may be processed in the order of S15 → S14. The phase amount Φ1 (k) is input to the phase shift amount setting means 371. The phase shift amount is set in the variable phase shifter 141 by the phase shift amount setting means 371 (S16).

Subsequently, the phase shift amounts of the variable phase shifters 142 to 144 are updated in the same procedure. Above phase shift control means
After the operation of updating the phase shift amounts of the variable phase shifters 141 to 144 by K is repeated K times, the operation is stopped by the update stopping means 19 (S17 to S18). In the present invention, during the operation of updating the phase shift amount, the phase shift amount largely fluctuates, so that the intensity of the received signal input to the demodulator 6 also fluctuates greatly, making demodulation processing difficult. Therefore, it is necessary to stop after repeating the operation of updating the phase shift amount a predetermined number of times.

Therefore, it is determined in step S17 whether i is equal to or greater than n. If i is equal to or greater than n, it is determined in step S18 whether k is equal to or less than K. In some cases, the numerical value is incremented by one, and the processing of S7 to S17 is repeated. When k is not smaller than K, the processing is stopped.

Here, the operation is stopped by counting the number of repetitions of the phase shift amount update.
It is also conceivable to stop the operation when i'-Pi "becomes equal to or less than a predetermined value.

Pi'-Pi "is

[0060]

(Equation 3)

Is expressed as follows. Here, i is an integer satisfying 0 ≦ i ≦ n, and Im ｛｝ is an imaginary part.

On the other hand, the partial differential δP / δΦi of P with respect to Φi
Is

[0063]

(Equation 4)

Is expressed as follows.

From the above, δP / δΦi = (Pi′−P
i ″) / 2 holds. Therefore, the processing in S12 is

[0066]

(Equation 5)

This means that processing equivalent to the above is performed.

When the real number α is a negative value, the phase shift amounts of the variable phase shifters 141 to 144 are updated so as to reduce the output signal strength of the adaptive array antenna, and finally δP / δΦ
Since the phase shift amount at which i = 0 is set, when only an interference wave exists, it can be suppressed. When such a phase shift amount control is applied to, for example, an adaptive array antenna for reception of a base station, the phase shift amount of the variable phase shifter is controlled before a communication channel is given to a terminal station that has requested communication. Then, to calculate the amount of phase shift to suppress co-channel interference, thereafter, give the communication channel to the terminal station,
Variable phase shifter 14 for controlling the phase shift amount for suppressing the co-channel interference
A method of setting the number to 1 to 144 and receiving a signal transmitted by the terminal station can be considered.

When the desired wave and the interference wave are present at the same time,
By fixing the amount of phase shift of one or more variable phase shifters to an initial value, suppression of a desired wave can be avoided.

As described above, nulling and suppressing an interference wave shown in Japanese Patent Application No. 11-125323 “adaptive antenna” is used in the present embodiment.

As shown in FIG. 3, the same weight may be set at all times, or a plurality of weights may be calculated in one cycle of the power supply due to a difference in timing, and the weight to be set at the timing may be set. You may switch.
By doing so, an optimal weight can be set for each timing and the interference suppression effect can be enhanced.

Further, by giving the base station timing information for generating a null that suppresses an interference wave in the microwave oven, the base station can also notify the terminal that the terminal transmits at a timing with low interference.

In the present embodiment, weight control is performed using only the received power after the combination (Japanese Patent Application No. 11-125323 described above), but a complex baseband signal of each element may be used.

As a weight calculation algorithm, for example, a power minimization method for suppressing an incoming wave can be considered. In a system in which a training signal of a desired wave is known, a least square error method or the like can be used.

The direction of arrival of the arriving wave is estimated and stored based on the received data obtained at a predetermined timing in one cycle of the power supply, and the stored arrival direction is stored at least at the predetermined timing in the power supply cycle. The weight can be calculated and set based on. With this configuration, it is possible to suppress the microwave interference wave whose generation cycle is equal to the power supply cycle, and further suppress other interference (such as other system interference). For example, when using the direction-constrained power minimization method, if the power force is minimized under the constraint of directing the directivity null in the estimated arrival wave direction, the microwave wave interference has already been suppressed, so the algorithm Can be quickly converged.

As described above, by utilizing the characteristic that the occurrence timing of interference between microwave ovens is constant irrespective of the starting timing of the microwave oven, a certain timing can be obtained if a microwave oven with close interference occurrence timing is located nearby. Can reduce the number of arriving wave sources, and thus the number of antenna elements can be reduced.

Conversely, if microwave ovens having different interference occurrence timings are located close to each other, it is not necessary to switch the pattern depending on the timing. (Second Embodiment) Next, a second embodiment of the present invention will be described. Since the second embodiment is basically the same as the first embodiment, the following description focuses on the differences from the first embodiment.

FIG. 9 shows a configuration example of the adaptive array antenna according to the present embodiment. The difference from the first embodiment is that the timing control circuit 16 includes a first timing determination device 16.
4 is added, the first timing determination device 164 is a power synchronization device 161 corresponding to the maximum reception power among the reception powers detected by the reception power detection device 18.
Is set in the timing storage device 162.

The first timing determination device 164 is composed of a received power storage device 1641 and a maximum power selection device 1642. The received power storage device 1641 stores the received power detected by the received power detection device 18 corresponding to the counter value output by the power synchronization device 161. FIG. 10 shows an example of the storage contents of the reception power storage device 1641. Further, the maximum power selection device 1642 selects the counter value corresponding to the maximum reception power in a state where the reception power storage device 1641 stores the reception power corresponding to all the counter values output by the power supply synchronization device 161 and stores the timing value. Set to the device 162.

That is, a data acquisition trigger can be supplied from the timing control device to the adaptive array antenna weight control device 17 for the maximum received power during the time when the adaptive array antenna is receiving, As a result, the adaptive array antenna performs control for directing nulls toward the microwave oven.

Next, the operation of the adaptive array antenna according to the second embodiment will be described with reference to FIG. FIG.
In FIG. 1, as described in the first embodiment, time is taken on the horizontal axis and signal level is taken on the vertical axis, time is divided for each power supply cycle, and one cycle of the power supply cycle is divided into a plurality of times. It can be shown that the interference wave of the microwave oven B is generated every period.

Therefore, in the second embodiment, the maximum received power in the period during which the adaptive array antenna is receiving by the first timing determination device in one cycle (A) (1 to n) of the power supply cycle. , A section B (e1 to e2) is determined, and data of the section B (e1 to e2) is sampled in the next cycle (B) to obtain reception level data detected by the reception power detection device. The weight is calculated for each data sample.

For the subsequent periods ((C) and (D)), the interference wave of the microwave oven can be suppressed by adding the above-mentioned weight.

Next, the timing control device 16 shown in FIG. 9 will be described. The power supply synchronizer 161 outputs a counter value (1 to e1 to e2 to n) to be initialized every power cycle.
The timing storage device 162 stores a counter value (e1 to e2) corresponding to the data acquisition timing determined by the first timing determination device. The first trigger 163 outputs a data acquisition trigger when the counter value output from the power synchronization device 161 is equal to the counter value (e1 to e2) stored in the timing storage device 162. In addition, the output of the power synchronization device 161 is input to the power synchronization device, and the power synchronization device outputs a control signal for stopping the operation of the first trigger device when the counter output by the power synchronization device makes one revolution.

Next, the operation procedure of the first timing determination device 164 having the above configuration is shown in FIG.

First, an initial control signal from a control unit (not shown) for controlling the adaptive array antenna is supplied to the weight control device 19 and the timing control device 16, and
The weights set in the weighters 141 to 144 and the counter of the power supply synchronizer 161 are initialized (S1).

Next, the reception power detected by the reception power detection device 18 is stored in the reception power storage device 1641 together with the output of the power supply synchronization device 161 (S2).

Next, after confirming that the received power data corresponding to all the outputs of the power synchronizer 161 is stored in the received power storage device 1641 (S3), the maximum power selection device 1642 corresponds to the maximum received power. The output value of the power supply synchronizer 161 is selected and set in the timing storage device 162 (S4).

FIG. 11 shows the effect of suppressing microwave oven interference by the weight control of the second embodiment. As shown in FIG. 11, the interference reduction effect can be improved by intensively reducing the interference wave having a high reception level.

If the section for reducing the interference wave is limited, the number of interference waves to be suppressed is reduced, so that the number of antenna elements can be reduced. 2. When used in the 4 GHz band, there is a physical limitation on the number of antenna elements because the spacing between antenna elements is large. Therefore, it is important to reduce the number of interference wave sources to be suppressed.

In this embodiment, the reception power level after the combination is detected, but the reception power level at the antenna element can be used. (Third Embodiment) Next, a third embodiment of the present invention will be described. Since the third embodiment is basically the same as the second embodiment, the following description focuses on the differences from the second embodiment.

FIG. 13 shows a configuration example of the adaptive array antenna according to the present embodiment. The difference from the second embodiment is that the configuration of the first timing determination device 164 provided in the timing control circuit 16 is different, and will be described as a second timing determination device 165.

The second timing determination device 165 is a power synchronization device corresponding to the minimum received power which is equal to or greater than a predetermined threshold value among the received powers detected by the received power detection device 18.
The counter value output by the 161 is set in the timing storage device 162.

The second timing determining device 165 comprises a received power storage device 1651, a minimum power selection device 1652 and a power threshold storage device 1653. Receive power storage device 1651
Stores the reception power detected by the reception power detection device 18 corresponding to the counter value output by the power synchronization device 161. The threshold value storage device 1653 stores a threshold value of the required suppression level of the received power. The minimum power selection device 1652 stores the received power corresponding to all the counter values output by the power supply synchronizer 161 in the received power storage device 1641 and stores the received power in the threshold storage device.
The counter value corresponding to the minimum received power that is equal to or larger than the threshold of the received power stored by 1653 is selected and set in the timing storage device 162.

That is, from the timing control device 16 to the adaptive array antenna weight control device 17, data acquisition is performed during the time during which the adaptive array antenna is receiving data while the reception power is equal to or higher than the threshold value and for the minimum reception power. A trigger can be provided, which controls the adaptive array antenna to steer nulls in the direction of the microwave.

The operation of the adaptive array antenna according to the third embodiment will be described with reference to FIG. In FIG. 14, the horizontal axis represents time, as described in the first embodiment.
Take the signal level on the vertical axis, separate the time for each power cycle,
Further, when one cycle of the power supply cycle is divided by a plurality of times, it can be shown that interference waves of the microwave ovens A and B are generated for each cycle.

Therefore, in the second embodiment, the threshold value of the reception power during the time when the adaptive array antenna is receiving by the second timing determination device in one cycle (A) (1 to n) of the power supply cycle. The section C (f1 to f2) for the above and minimum reception power is determined, the data of this section C (f1 to f2) is sampled in the next cycle (B), and the reception level detected by the reception power detection device is obtained. Data is acquired, and a weight is calculated for each data sample in the section C (f1 to f2).

[0098] For the subsequent periods ((C) and (D)), the interference wave of the microwave oven can be suppressed by adding the above-mentioned weight.

Next, the timing control device 16 shown in FIG. 13 will be described. The power supply synchronizer 161 outputs a counter value (1 to f1 to f2 to n) initialized for each power supply cycle. The timing storage device 162 stores a counter value (f1 to f2) corresponding to the data acquisition timing determined by the second timing determination device. The first trigger 163 outputs a data acquisition trigger when the counter value output from the power supply synchronization device 161 is equal to the counter value (f1 to f2) stored in the timing storage device 162. In addition, power synchronizer
The output of 161 is input to the power supply synchronous counter, and the power supply synchronous counter outputs a control signal for stopping the operation of the first trigger device when the counter output by the power supply synchronous apparatus makes one revolution.

Next, the operation procedure of the second timing determination device 164 having the above configuration is shown in FIG.

First, an initial control signal from a control unit (not shown) for controlling the adaptive array antenna is supplied to the weight control device 17 and the timing control device 16, and
The weights set in the weighters 141 to 144 and the counter of the power supply synchronizer 161 are initialized (S1).

Next, the received power detected by the received power detection device 18 is stored in the received power storage device 1651 together with the output of the power supply synchronization device 161 (S2).

Next, after confirming that the received power data corresponding to all outputs of the power synchronizer 161 is stored in the received power storage device 1651 (S3), the minimum power selection device 1652 stores the received power data in the power threshold storage device 1653. The power supply synchronizer 16 which is equal to or more than the threshold value of the stored reception power and corresponds to the minimum reception power.
The output value of 1 is selected and set in the timing storage device 162.
(S4).

FIG. 14 shows the effect of suppressing microwave oven interference by weight control according to the third embodiment. As shown in FIG. 14, when the reception level is closest to the required suppression level of the interference wave and the interference wave with the minimum power is intensively reduced, the timing at which the interference level is relatively easy to suppress in a situation where there are many interference waves at or above the required suppression level Therefore, the degree of freedom of the antenna element can be effectively used by suppressing the interference wave in a concentrated manner. (Fourth Embodiment) Next, a fourth embodiment of the present invention will be described. Since the fourth embodiment is basically the same as the first embodiment, the following description focuses on differences from the first embodiment and the second embodiment.

In the fourth embodiment, the number of power cycle counters 1631 in FIG. 2 is different. First
In the embodiment, the power supply synchronization counter 1631 is
While the control signal for stopping the operation of the first trigger device 163 is output when the counter output by 1 makes one cycle, the fourth embodiment outputs the control signal when the counter makes a predetermined number of times, for example, two times. The control signal for stopping the operation of the trigger device 163 is output.

With such a configuration, the number of usable data is larger than when weights are calculated using one cycle of data, so that interference suppression performance can be improved.

Further, the operation of the adaptive array antenna according to the fourth embodiment will be described with reference to FIG. In FIG. 16, the time is plotted on the horizontal axis as described in the first embodiment.
Take the signal level on the vertical axis, separate the time for each power cycle,
Further, when one cycle of the power supply cycle is divided by a plurality of times, it can be shown that interference waves of the microwave ovens A and B are generated for each cycle.

Thus, in the fourth embodiment, a predetermined section A (d1 to d1 to d1 to d2 to n) of one cycle (A) of the power supply cycle is used.
2) and data of a predetermined section A (d1 to d2) corresponding to the cycle (A) of the next cycle (B) is acquired to obtain reception level data detected by the reception power detection device;
The weight is calculated for each data sample in the section A (d1 to d2).

For the subsequent periods ((C) and (D)), the interference wave of the microwave oven can be suppressed by adding the above-mentioned weight.

Next, the operation procedure of the first timing determination device 164 having the above configuration is shown in FIG.

First, an initial control signal from a control unit (not shown) for controlling the adaptive array antenna is supplied to the timing control device 16, and the counter of the power supply synchronization device 161 is initialized to 0 (S1).

Next, the output of the power supply synchronization device 161 is input to the first trigger device 1613 and the power supply cycle counter 1631 (S
2).

Next, the power supply cycle counter 1631 makes one round of the clock counter, that is, determines whether the clock value of the power supply synchronizer 161 is the maximum (S3). If the clock value is maximum, the value of the power supply cycle counter 1631 is increased (S4). . Next, the value of the power supply cycle counter 1631 is compared, and when the value reaches the predetermined value, a control signal for stopping the operation of the first trigger device 163 is output, and the operation ends (S5).

If the value is not reached, the power synchronization device
The output of 161 is compared with the counter value stored in the timing storage device 162 (S6). When the counter values are equal, the first trigger 163 sets the data acquisition trigger to the weight control device 17.
(S7).

FIG. 18 shows the effect of suppressing microwave microwave interference by weight control. As shown in this figure, since weight calculation is performed by sampling data of two periods, the number of usable data can be increased, and the interference suppression performance can be improved.

[0116]

As described above, in the adaptive array antenna of the present invention, when the microwave oven is in operation, the weight for suppressing the microwave interference wave based on the reception data acquired at a predetermined timing in one cycle of the power supply. Is calculated and stored, and thereafter, by setting the stored weight at the aforementioned timing in the power supply cycle, interference can be suppressed efficiently.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining a wireless LAN system according to a first embodiment of the present invention;

FIG. 2 is a diagram showing a configuration example of an adaptive array antenna according to the first embodiment of the present invention.

FIG. 3 is a diagram showing weight control of the adaptive array antenna according to the first embodiment of the present invention.

FIG. 4 is a flowchart showing an example of an operation procedure of the adaptive array antenna according to the first embodiment of the present invention.

FIG. 5 is a flowchart showing an example of an operation procedure of the timing control device according to the first embodiment of the present invention.

FIG. 6 is a flowchart showing an example of an operation procedure of the power supply synchronizer according to the first embodiment of the present invention.

FIG. 7 is a diagram showing a configuration example of an adaptive array antenna according to the first embodiment of the present invention.

FIG. 8 is a flowchart showing weight control of the adaptive array antenna according to the first embodiment of the present invention.

FIG. 9 is a diagram showing a configuration example of an adaptive array antenna according to a second embodiment of the present invention.

FIG. 10 is a diagram showing an example of contents stored in a reception power storage device according to a second embodiment of the present invention.

FIG. 11 is a diagram showing weight control of an adaptive array antenna according to a second embodiment of the present invention.

FIG. 12 is a flowchart showing an example of an operation procedure of the first timing determination device according to the second embodiment of the present invention.

FIG. 13 is a diagram showing a configuration example of an adaptive array antenna according to a third embodiment of the present invention.

FIG. 14 is a diagram showing weight control of the adaptive array antenna according to the third embodiment of the present invention.

FIG. 15 is a flowchart showing an example of an operation procedure of the second timing determination device according to the third embodiment of the present invention.

FIG. 16 is a diagram showing weight control of an adaptive array antenna according to a fourth embodiment of the present invention.

FIG. 17 is a flowchart showing an example of an operation procedure of the timing control device according to the fourth embodiment of the present invention.

FIG. 18 is a diagram for explaining a conventional wireless LAN system.

[Explanation of symbols]

 1 Adaptia array antenna 2 Base station 3 Terminal 111-114 Antenna element 121-124 Amplifier 131-134 ..Frequency converters 141 to 144 ・ ・ ・ Weighting device 15 ・ ・ ・ ・ ・ ・ Synthesizer 16 ・ ・ ・ ・ ・ ・ Timing control device 161 ・ ・ ・ ・ ・ ・ ・ Power supply synchronizing device 1611 1612 ····· Power supply cycle storage device 1613 ······ Clock counter 162 ······ Timing storage device 163 ······ First trigger 1631 ······ Power supply synchronous counter 164 ··· ..First timing determining device 1641... Received power storage device 1642... Maximum power selecting device 165... Second timing determining device 1651... Power threshold storage device 1652 ... Minimum power selection device 17 ... Weight control device 18 ... Reception power Detection device

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5J021 AA05 AA06 CA06 DB02 DB03 EA04 FA14 FA15 FA16 FA17 FA20 FA29 FA30 FA32 HA05 HA10 5K059 CC03 CC04 DD31 5K067 AA03 BB21 EE02 EE10 GG11 HH22 HH23 KK02 KK03

Claims (15)

[Claims] An adaptive array antenna for controlling a directional pattern by adding weights to a plurality of weight controllers, based on received data acquired at a predetermined timing in one cycle of an operation power supply of an interfered object. An adaptive array antenna, wherein a weight for reducing an interference wave from an interfered object is calculated and stored, and the stored weight is set at a predetermined timing during which the received data is obtained in a subsequent power supply cycle. 2. The method according to claim 1, wherein the predetermined timing for acquiring the reception data is one or more timings including a timing at which the reception level becomes maximum in one cycle of the power supply. Adaptive array antenna. 3. The method according to claim 2, wherein the predetermined timing for acquiring the reception data is one or more timings including a timing at which the reception level is equal to or more than a predetermined value and becomes minimum in one cycle of the power supply. The adaptive array antenna according to claim 1. 4. The reception data for calculating the weight is obtained at the predetermined timing over two or more power supply cycles.
The adaptive array antenna according to claim 1. 5. A plurality of antenna elements, a plurality of weighters for respectively weighting received signals received by the plurality of antenna elements, and a combiner for combining received signals weighted by the plurality of weighters. A timing control device that outputs a data acquisition trigger at a predetermined timing for each power supply cycle of the interfered object, and acquires reception data received by at least one of the antenna elements when the timing control device outputs a data acquisition trigger An adaptive array antenna, comprising: a weight controller that calculates a weight for reducing an interference wave from the interfered object for each predetermined data sample and sets the weight for the plurality of weighters. 6. A reception power detection device for detecting a power of a reception signal received by at least one of the antenna elements, and determining a timing of an acquisition trigger output from the timing control circuit according to the reception signal. The adaptive array antenna according to claim 5, wherein 7. A power supply synchronizing device for outputting a counter value initialized for each power supply cycle, the timing control device comprising:
A timing storage device that stores a counter value corresponding to a predetermined data acquisition timing; and a power supply trigger that outputs a data acquisition trigger when the counter value output by the power supply synchronization device is equal to the counter value stored in the timing storage device. The adaptive array antenna according to claim 5, further comprising: a first trigger that stops operation when a counter output by the synchronizer makes one rotation. 8. A power synchronization device, comprising: a clock generation device for generating a clock at a predetermined cycle; a power cycle storage device for storing a number of clocks corresponding to the power cycle; and a clock generated by the clock generation device. 8. The adaptive array antenna according to claim 7, further comprising a clock counter that counts and initializes a counter for each clock number stored in the power cycle storage device. 9. A reception power detection device for detecting a power of a reception signal received by at least one of the antenna elements, and a timing determination device for giving a counter value to the timing storage device according to the reception signal. The adaptive array antenna according to claim 7, wherein: 10. The timing determining device sets a counter value output by the power synchronizer corresponding to the maximum received power among the received powers detected by the received power detecting device in the timing storage device. The adaptive array antenna according to claim 9, wherein 11. A reception power storage device for storing reception power detected by the reception power detection device corresponding to a counter value output by the power supply synchronization device, and a timing output by the power supply synchronization device. In the state where the received power detected by the received power detection device corresponding to all the counter values is stored in the received power storage device, a counter value corresponding to the maximum received power is selected and set in the timing storage device. The adaptive array antenna according to claim 9, further comprising a power selection device. 12. The timing storage device according to claim 1, wherein the timing determination device outputs a counter value output by the power supply synchronizer corresponding to a minimum reception power equal to or more than a predetermined threshold among the reception power detected by the reception power detection device. 10. The adaptive array antenna according to claim 9, wherein: 13. A reception power storage device for storing reception power detected by the reception power detection device corresponding to a counter value output by the power supply synchronization device, and a reception power threshold value. A threshold storage device;
The received power detected by the received power detection device corresponding to all the counter values output by the power supply synchronization device is greater than or equal to the threshold of the received power stored by the threshold storage device in a state where the received power storage device stores the received power. The adaptive array antenna according to claim 9, further comprising: a minimum power selection device that selects a counter value corresponding to a minimum reception power and sets the counter value in the timing storage device. 14. The timing control device counts a counter value output by the power synchronization device and supplies a control signal to the trigger device to stop the operation of the trigger device when the count value reaches a set count value. The adaptive array antenna according to claim 7, further comprising: 15. The adaptive array antenna according to claim 1, wherein the interfered object is a microwave oven.