JP2001326525A - Directivity control method for array antenna - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an array antenna directivity control method capable of solving the problem on communication quality which occurs due to an error related to the directivity control of an array antenna, for instance, a direction estimation error, an error of the control system itself of the antenna, etc. SOLUTION: In this method, an antenna weight coefficient is controlled so that the antenna gain of a side lobe turned in a relatively wide direction including the direction of interference potential coming from a direction in which reception is unintended is regulated to a fixed value or below with respect to the interference. A plurality of antenna weight coefficients are preliminarily decided and stored as a table in a base station side, and a corresponding weight coefficient is referred to according to the position of a mobile station.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a directivity control method for a phased array antenna, and more particularly to a method for separating a target radio wave and an interference radio wave by using the directivity of an array antenna. The present invention relates to a directivity control method for an array antenna which facilitates a space division multiple access method.

[0002]

2. Description of the Related Art In recent years, a space division multiple access system has been proposed as a technique for dynamically changing the directivity of an antenna in accordance with a propagation environment to improve communication quality and frequency use efficiency. The space division multiple access system is a system for simultaneously transmitting or receiving signals at the same frequency between one base station and a plurality of mobile stations.

When communication is performed between a single base station and a single mobile station as in normal communication, good directivity is set by setting the directivity of the antenna of each station to the direction of the partner station. Communication can be performed. However, in order to simultaneously perform good communication between a single base station and a plurality of mobile stations, it is necessary to adjust the directivity of the antenna. For example, the directivity of the antenna of the base station may be disturbed by setting a high antenna gain in the direction of the mobile station performing communication and setting a low antenna gain in the direction of the mobile station not performing communication. It is required to reduce radio waves. In addition, it is also required that the directivity pattern be set so that optimal communication is sequentially performed as the mobile station moves.

[0004] In order to realize such a space division multiple access scheme, an array antenna represented by an adaptive array or the like and an antenna directivity control technique using digital signal processing have been attracting attention. The adaptive array is also called an adaptive array antenna, but here, for simplicity, an adaptive array is used.

In general, when directivity control is performed by using an array antenna of an adaptive array, a directivity pattern includes a main beam in a main direction, side lobes in a direction other than the main direction, and a null point. Here, the main beam is the highest direction of the directivity pattern of the antenna, the side lobe is the high direction of the directivity pattern other than the main beam, and the null point is the direction indicating the dip in the directivity pattern. The number of side lobes and null points depends on the number of array elements and the arrangement interval of elements. like this,
In an adaptive array, as is well known, a digital signal received through an array antenna is subjected to a complex function analysis to obtain and operate a complex weight coefficient of an optimal array element for receiving a target signal. Thus, the directivity of the antenna is controlled to an intended pattern.

One of the analysis algorithms at this time is as follows:
(1) There is a method based on the first method of controlling the power of a desired signal to be maximum based on a reference signal included in a signal to be received. This method has the advantage that the optimal weighting factor of the array antenna can be derived without estimating the direction of arrival, but the respective frequencies of the radio waves transmitted from the mobile station to the base station and the radio waves transmitted from the base station to the mobile station In the case where is different, it is necessary to provide a weighting factor of the array antenna to the transmitting antenna of the base station, and on the contrary, the control becomes complicated.

According to another analysis algorithm, (2) the arrival direction of the signal to be received is estimated, and the direction in which the signal to be received arrives and the direction in which the interference signal arrives are known.
There is a method based on the second method in which the directivity peak of the array antenna is directed to the direction of the radio wave to be received, and the null point of the antenna is directed to the direction of the interference wave.
This method is applicable even when the frequency of the radio wave transmitted from the mobile station to the base station and the frequency of the radio wave transmitted from the base station to the mobile station are different, and has an advantage that the applicable range is wide. Is limited, the number of interference waves that can be suppressed is limited, and there is a weak point derived from the directional pattern shape near the null point. That is, since the antenna gain is low only at the null point, if the position of the interference wave is slightly shifted, the antenna gain is increased and the interference wave cannot be sufficiently removed.

The method of the present invention is in accordance with the above-mentioned second method. The point that the main beam of the array antenna is directed in the direction of a desired signal is the same as the conventional method, but differs from the conventional method in setting the side lobe and the null point.

In general, as the number of elements of an array antenna increases, the number of null points also increases. However, the number of null points depends on the number of elements and the element interval of a phased array antenna. In particular, when the array elements are arranged at half-wavelength intervals, the number is limited to (the number of element antennas-1). That is, the first weak point is that the number of directions in which these null points can be directed is limited, and thus the number of stations that can avoid interference is limited. As a second weakness derived from the directivity pattern shape, there is a weakness that the performance of separating a signal to be received from a signal to be avoided is easily deteriorated even with a small error in the direction of arrival. Further, as a third weakness of this method, even if the antenna directivity pattern can be derived by calculation, there is no guarantee that the value is an optimum value.For example, when transmitting from the base station side to the mobile station side, the antenna It is necessary to check the directivity pattern derived on the base station side to determine whether the directivity pattern can be optimized and communication quality can be maintained on the mobile station side. In particular, when a plurality of mobile stations are adjacent to each other, it is necessary to confirm. Because of this complexity, adaptive arrays have not hitherto been used in such space division multiple access applications.

In the conventional directivity control method for an array antenna, when a plurality of stations transmit and receive signals at the same frequency, the directivity of the array antenna is estimated using information on the estimated arrival direction of the received radio wave and signal power. Even if you control,
When a plurality of mobile stations are close to each other, there has been a situation where signals cannot be spatially separated. (Here, the inability to spatially separate means that when a base station communicates with a plurality of mobile stations at the same frequency, a signal transmitted to another mobile station is transmitted to a certain mobile station. It is a situation in which a constant communication quality cannot be ensured due to the interference wave. In such a situation where signals cannot be spatially separated, space division multiple access is impossible, so the base station separates the radio wave in the intended direction of arrival at the mobile station based on the location information of the mobile station. Some kind of judgment was made to recognize whether the communication was possible or inseparable, and whether communication was possible or not was determined.

In the second method, the directivity peak of the array antenna is directed in the direction of the radio wave to be received, and the null point is directed in the direction of the interference wave. It had the drawback derived from the sexual pattern.

Most of the conventional methods use the desired wave direction and the interference wave direction as essential input values, and if necessary, the antenna gain for the desired wave direction and the antenna gain for the interference wave direction as the input values. This is a method to derive the weighting factor of the array antenna that forms the directional pattern.

[0013] In order to explain the above-mentioned drawbacks, for example, a document (Simon Haykin, Adaptive Filter)
LCMV method (Linearly Constrained Minimum Vari) described in Theory (Third edition), Prentice Hall, 1996).
ance beam forming algorithm). Here, the LCMV method is referred to as algorithm 1.

When the number of array elements is N, the direction in which the beam is to be directed is θs, and the range in which the beam is not desired is θa to θb, the array response vector v (θ) in the θ direction is expressed by the following equation (1). .

(Equation 1)

In equation ( ₁ ), ω is the frequency, g _l (θ) is the complex gain in the θ direction of the l-th element, and τ _l (θ) is the time delay. In addition, the array response vectors v (θs) and v (θa) for θs and θa are simplified below, and described as vs and va, respectively. At this time, the weight coefficient of the array antenna is obtained from the following equation (2).

[0016]

(Equation 2)

Here, w is a weight coefficient vector of the array antenna, a vector of N rows and 1 column, H is a complex conjugate transpose, C is a constraint matrix (M rows and N columns), and f is a constraint response vector (N rows and 1 column).
Column). C and f are given by Expression 3, and satisfy the condition of Expression 4.

[0018]

(Equation 3)

[0019]

(Equation 4)

A is a matrix of N rows and N columns.
Given by

(Equation 5) Here, σ _n ² is a very small positive value, and I is a unit matrix.

As typified by Algorithm 1, the desired wave direction and the interference wave direction are set as essential input values, and the antenna gain for the desired wave direction and the antenna gain for the interference wave direction are set as the input values if necessary. It is known that the shape of the null point becomes a very sharp valley in the directivity pattern of the array antenna based on the obtained weight coefficient of the array antenna.

As means for solving the above problem, a desired direction, an antenna gain in a desired direction, and a certain range and an antenna gain within the range are designated, and the antenna gain is within the designated limited range. A method of setting a predetermined condition for the maximum gain of a plurality of side lobes and setting a wide range of low antenna gain has been proposed, for example, in the literature (Ching-YuhTseng, Lloyd J. G.
riddiths, "A simple algorithm to achieve desired p
atterns for arbitrary arrays ", IEEE Trans. on signa
l processing, vol. 40, No. 11, Nov. 1992).

As described above, to control the side lobe, the weight coefficient of the array antenna is modified as shown in the following procedure. Here, this method is referred to as Algorithm 2, and description will be made using the same symbols as those used in Equations 1 to 5. One. First, the weight coefficient w of the array antenna is obtained by the above-described conventional method. 2. Next, from the beam pattern calculated from the weight coefficient w of the array antenna, the position and magnitude of the peak of the side lobe existing in the range of θa to θb are examined. The number of side lobes is defined as m, the array response vector in the peak direction is defined as v _i (i = 1..m), and the value of each peak is defined as c _i (i = 1..m). . Here, c _i is a complex number.

3. Next, in order to obtain a correction term of the weighting factor of the array antenna having a side lobe size of less than or equal to, a parameter indicating a difference in directivity is f _i (i = 1.
m)

(Equation 6) F _i (i = 1..m) that satisfies

[0025]

(Equation 7)

4. Next, matrix A, matrix C, vector f,
Is given as Equations 8 and 9, and Equation 10 is solved.

(Equation 8)

[0027]

(Equation 9)

[0028]

(Equation 10)

5. Next, substituting w ← w + Δw, θa ~
The magnitude of the peak of the side lobe during θb is denoted by c _i (i =
One. . . Steps 2 to 5 above are repeated until the absolute value of m) becomes a desired value (not more than ε).

According to the method outlined above, in order to specifically calculate the weighting factor of one array antenna, the calculation time becomes enormous even if a general electronic computer is used, and real-time processing is required. There was a drawback that it was not suitable for operation of a real system.

[0031]

SUMMARY OF THE INVENTION The present invention has been proposed in view of the problems with the above algorithms 1 and 2, and is premised on introduction into a real system requiring real-time processing. A directivity control method for an array antenna that can solve communication quality problems caused by related errors, for example, a direction estimation error and an error of an antenna control system itself, and improve communication quality as compared with the conventional method. The purpose is to propose.

The invention for Algorithm 1 described below, Method 1, aims at adding a procedure to a general algorithm to overcome the above-mentioned weak points and to be suitable for practical use. Furthermore, the invention for Algorithm 2 described later, Method 2, overcomes the drawback specialized in Algorithm 2, that is, the problem derived from computation time,
The purpose is to add procedures so as to be suitable for practical use.

[0033]

In order to achieve the above object, the invention according to claim 1 relates to a directivity control method of an array antenna, wherein substantially a single reception should be performed in a main lobe direction. A procedure for adjusting the radio wave source to be included, a procedure for suppressing the maximum antenna gain in each side lobe below a predetermined antenna gain within a predetermined range of radio wave arrival directions, and a reception within this range And a procedure for adjusting so as to include radio sources that should not be included.

[0034] The invention described in claim 2 is the same as the claim 1.
In addition to the invention described in the above, a procedure for creating a table that associates the directions that can be covered by the main lobe direction and the side lobe direction, and the direction in which the radio wave to be received is directed to the main lobe direction with reference to the above table And a procedure for determining whether or not the direction of the side lobe can be directed to the arrival direction of the radio wave that should not be received.

The third aspect of the present invention relates to a method for controlling the directivity of an array antenna. A predetermined condition is provided for the maximum gain of a plurality of side lobes within a limited range, and this condition is satisfied. A procedure for determining a plurality of weighting factors of the array antenna in advance and storing the weighting factors in a predetermined manner, and for each of the above weighting factors, the allocation of the base station and the mobile station, and the weighting factor table of the array antenna. From the procedure for preparing a correspondence table that takes correspondence between them and the location information about the mobile station, refer to the above correspondence table and determine whether the radio waves to be received and the radio waves to avoid receiving are spatially separable or impossible. If possible, select a weighting factor from the above-mentioned array antenna weighting factor table based on the information in the correspondence table, and if not possible, take a predetermined correspondence procedure, It is characterized in that it has a, a procedure for controlling an array antenna using a weighting factor.

The fourth aspect of the present invention relates to a method for controlling the directivity of an array antenna. A predetermined condition is provided for the maximum gain of a plurality of side lobes within a limited range, and this condition is satisfied. A procedure of determining a plurality of weighting factors in advance and storing the weighting factors in a predetermined manner, and the above-mentioned weighting factors correspond to the location of the base station, the location of the mobile station, and the weighting factor table of the array antenna. From the procedure for preparing the correspondence table and the location information on the mobile station, refer to the above correspondence table, determine whether the radio wave to be received and the radio wave to avoid receiving are spatially separable or impossible, and if possible, ,
A weighting factor is selected from the above-mentioned array antenna weighting factor table based on the information in the correspondence table, and if it is not possible, a procedure for taking a predetermined correspondence and an array antenna using the selected weighting factor are used. And after a predetermined time, update the location information of the mobile station, refer to the correspondence table again from the location information related to the mobile station, and determine the radio wave to be received and the radio wave to be avoided. Judge whether it is spatially separable or impossible.If possible, select a weighting factor from the above-mentioned array antenna weighting factor table based on the information in the correspondence table. And a procedure for returning to a procedure for taking a response.

According to a fifth aspect of the present invention, in addition to the method of the third or fourth aspect, the arrival direction of a signal to be received by the array antenna and the arrival of a signal not to be received are provided. The direction is characterized in that it includes a procedure for determining a weight coefficient of an array antenna so as to compensate for a decrease in antenna gain due to an error generated from the characteristics of the device.

According to a sixth aspect of the present invention, in addition to the method of the third or fourth aspect, the weight coefficient of the array antenna at a representative point in the area where the mobile station moves is received. It is characterized by including a procedure prepared before communication together with information on the direction of arrival of the signal to be received and the direction of arrival of the signal not to be received, stored by the storage means, and utilizing the information accumulated in the storage means at the time of communication. .

According to a seventh aspect of the present invention, in addition to the method of the sixth aspect of the invention, a plurality of array antenna weighting factors at at least one representative point are prepared prior to communication. The weighting factor of the array antenna is stored by the storage means, and the method includes a procedure of selecting and utilizing the plurality of weighting factors stored in the storage means at the time of communication according to the situation.

According to the eighth aspect of the present invention, in addition to the method of the sixth or seventh aspect of the present invention, a situation is obtained based on the weighting factors of the plurality of array antennas stored in the storage means during communication. The method of selecting the weighting factor of the array antenna according to the above is characterized by including a procedure of determining whether the weighting factor of the array antenna for maintaining a constant communication quality is stored in the storage means.

According to a ninth aspect of the present invention, in addition to the method of the eighth aspect of the present invention, the above-mentioned procedure for determining the first array antenna stored in the storage means is provided. If a weight coefficient is not selected, the method includes a procedure of selecting a second weight coefficient that sets an antenna directivity capable of covering a plurality of mobile stations.

According to a tenth aspect of the present invention, in addition to the method of the ninth aspect, when utilizing the information stored in the storage means at the time of communication, the mobile information of the mobile station is used. Is used as prediction information, the weighting factor of the array antenna stored in the storage means is
It is characterized by including a procedure for predicting and selecting.

[0043]

Embodiments of the present invention will be described below in detail. First, the principle of the present invention will be described, and then embodiments will be described with reference to the drawings.

The outline of the present invention for solving the above-mentioned problem is that the array antenna is not controlled so that the null point of the array antenna is directed to an interference wave coming from a direction not intended for reception. Is controlled in the unintended direction, and the gain is set below a specified gain over a wide range. By doing this,
Even if an error occurs in the estimated interference wave direction, performance degradation can be suppressed to a small extent.

Next, algorithm 1 which is a disadvantage of the prior art
The shape of the null point becomes a very sharp valley when
An invention for solving the disadvantage that the influence of a small estimation error is large will be described in detail below.

The present invention derives a weighting factor of an array antenna having a side lobe having a low gain in a wide range as much as possible in the interference wave direction from information of a desired direction and an interference wave direction. The present invention also relates to storing the weighting factor of the array antenna derived by the technique as data and making it applicable to a mobile station at an arbitrary location in a service area.

For simplicity, as a first embodiment, a first method for deriving a weight coefficient of an array antenna when the number of users existing in a service area is 2 will be described below.

Here, the parameters required for the following algorithm
The parameters are as follows. Service area range R
And Here, the front direction of the array antenna is 0 degree.
Then R = [-θ_Area~ Θ_Area]. Also set
N_uAnd the interval for setting the interference wave direction,
That is, the interval for setting the null point is Δθ (small value)
And Here, Δθ is the direction of the null point (when Nu> 1)
Is the value that sets _uIndicates the distance from. Interference waves
And θ_uNu are set around. For example, if Nu = 2
The null point is set in two directions (θ_u-Δθ, θ_u+ Δ
θ), and when Nu = 3, in three directions (θ_u-Δθ, θ, θu
+ Δθ). Also, set the range for setting the desired direction to R
_pAnd the desired direction requested by the system
(Α) for the signal coming from the
Signal gain (β) and give between these gains
Let the gain difference be (α−β). This keeps the desired signal constant
The value required to receive with the signal quality of
Is given as a condition when designing.

Step 1: The desired direction is set to θ _d, and this is set to 0 degree with respect to the origin. Let the direction of the null point be θu, and derive one point from within the service area range R. That is, θu∈R.

Step 2: θ_uPositive and negative around the center
N away from each other (Δθ degrees)_uSet null point directions
You. Also, given the θ_d And θ_uN including_uNull points
Array antenna using algorithm 1 based on direction and
Is derived.

Step 3: According to algorithm 1, correct
Calculate the weighting factor w of the normalized array antenna and calculate this value.
, The expected antenna gain is calculated. Where
Antenna gain is θ_d Over a certain value α centered on
Enclosure p and θ_uRange q that is less than or equal to a fixed value β centered on
Find out. If either p or q is empty, step 5
Proceed to. Also, the range of q is the same θ_d,θ_uUsing the past
If the value is smaller than q derived in
No. Otherwise, go to step 4. Here
The meaning of the tip is_uAway from (that is,
Increase the interval of the point direction setting),
Then, the range that guarantees the gain β or less increases,
Increasing the spacing creates null points at each location.
The range that guarantees the gain β or less suddenly becomes narrower.
At this point, step 2
Then, the operation of step 5 is completed. For example, θ_u= 1 and N
_uWhen = 3, set the interference wave direction to three directions: 0.9, 1, 1.1.
Direction, there is a deep null point in the 1 degree direction, but interference
When the wave direction is set to 0, 1, and 2, the gain around 1 degree
Decline. However, by further increasing the spacing
And a null point can be created at each location,
At this time, the range that guarantees the gain β or less suddenly narrows.
End at the point.

Step 4: The correspondence between w and [p, q] is changed to w → [p,
q]. In addition, the interference wave direction setting is increased by Δθ, and the process returns to 2.

Step 5: Among the weighting coefficients in the specific setting of θ _d and θu, which are obtained by repeating Steps 2 to 4, have the maximum q range obtained by increasing Δθ. The weight coefficient w → [p, q] is stored in the table T.

Step 6: Returning to step 2 above, a new θ _u is set, and the weight coefficient w of the array antenna is set.
Calculate _new . However, it is assumed that w _new satisfies the following conditions. {w _new → [p _new , q _new ] | ∀r: (r ∈ (q _new ∩¬ (q _new ∩Q))) ∩ (r ∈ R)} where the meaning of the expression is newly derived in the gain derived from the w _{new new,} ranges so far not been part of the range q _{new new} to ensure less gain β guarantees a new, and r is such that within the area R desired, w _{new new,} Means

Step 7: In steps 2 to 6, a weighting factor corresponding to an arbitrary θ _u and focusing on a specific θ _d is recorded in T. Next, unnecessary weight coefficients w ′ of the array antenna, which are recorded in the table T but are unnecessary because they overlap, are deleted from the table T. However, w 'is assumed to satisfy the following conditions. {w '→ [p', q '] | q'⊆q∈Q, w → [p, q], w', w ∈
T}

Step 8: When a desired station direction, that is, a direction in which directivity is directed, is focused on a specific θ _d , among the antenna gains obtained from the obtained weighting factors of the array antenna, the antenna gain becomes α or more. Focus on the smallest range that satisfies the condition. That is, of the sections are stored in P, and p having the smallest section is a, the ranges excluding a from the service area range R to R _p. That is, when the function min () is a function that gives the element of the minimum section, a = min (P) and R _p ← (R _p -R _p ∩a.). Further, θ _d {θ _d ∈R _p } is newly determined, and the process returns to 2. Steps 2 to 8 are repeated until R _p becomes empty.

Step 9: Unnecessary array antenna weight coefficients w 'registered in the table T are deleted. However, it is assumed that w _new satisfies the following conditions. {w '→ [p', q '] | (p'⊆p∈P) ∩ (q'⊆q∈Q), w →
[p, q], w ', w ∈T}

Step 10: End. In the table T, information on the effective array antenna weighting factor w and information on the antenna gain determined by w remains.

Table T obtained by the above procedure
From the above, with regard to the weight coefficient of the array antenna, a correspondence table for associating the arrangement of the base station, the arrangement of the mobile station, and the weight coefficient table of the array antenna, and the array antenna in which the weight coefficient of the array antenna is listed Is easy to create. That is, in steps 1 to 10, it is possible to easily derive the weight coefficient of the array antenna when the user can be separated.

The features of the first method described above will be described below. First, as a first feature, the obtained solution is not always the optimal solution, but it is possible to derive only the solution that always satisfies the requirements.

[0061] As a second aspect, in the first approach, the range for setting the null point is set to 0～Shita _Area, in the range of - [theta] _Area ~0, obtained in 0～Shita _Area It is possible to apply the results and use them. Specifically, the weighting factor obtained in the range of 0 to θ _Area
w ₁ ,. . . w _M , w _M ,. . . by replacing w ₁ in reverse order and, may be a weighting factor of the array antenna in the range of - [theta] _Area ~0.

[0062] As a third aspect, in the first technique described above, by introducing a set number N _u of the null point in the calculation procedure, the variable as examining the weighting coefficients of the array antenna is possible by computing is there. For this purpose, by changing the N _u, it may be repeated from Step 1 to 6.

As a fourth feature, in the first method, by setting the service area range R wider than the originally desired range, an array antenna that can be used in the range of the actually widened R is set. It is possible to increase the number of weighting factors. By doing so, a more suitable directivity pattern can be used.

As a fifth feature, in step 1 of the first method, in setting θ _u , the value is set in order from the end of R to reduce the complexity of calculation. Is possible.

As a sixth feature, in calculating the antenna gain by calculating the weight coefficient of the array antenna in step 3 of the first method, an error affected by components constituting the antenna is taken into account. By performing the calculation, it is possible to store, as information, a range in which a specific error can be allowed for the weight coefficient of each array antenna.

As a seventh feature, when removing the redundant array antenna weighting factor in the first method step 9, the above description removes the weighting factor of the array antenna whose shape is completely overlapped. However, it is possible to reduce the number of array antenna weight coefficients to be stored by removing the slightly overlapping portion.

As an eighth feature, in the first method, the range in which the interference wave can be suppressed (the antenna gain is equal to or less than β) is set to one place, but n (n
> 1) It is possible to cope with the case where the number of users is 2 or more by setting the number of locations. For this purpose, in step 2, the number of interference waves is set to one (θ _u ), and after the repetition up to step 6, the number of interference waves is reduced to (the number of users−
What is necessary is just to increase to 1) and repeat similarly. (When the calculation up to (the number of users −1) is completed, the process proceeds to step 7). In this way, the range that guarantees the gain β or less can be set at a plurality of points without remaining in some places. However, even when there are a plurality of mobile stations, it is possible to cope with the situation.

Further, as a ninth feature, by using the result of the combination of the mobile station having no corresponding weight coefficient and the direction of the interference wave obtained from the first method, an inseparable range is obtained. You can easily find out.

As described above, when the intended specific user is in an inseparable place, another multiple access method is used. This eliminates the need to spatially separate mobile stations, in which case the base station does not have to consider interference for each user, and thus the number of users in the area is two. In the case of (1), as the weighting factor of the selected array antenna, the weighting factor of the array antenna that sets the direction of each mobile station to the desired direction is selected.

Further, when the number of users is 3 or more and the intended specific user includes an inseparable user,
The weighting factor of the array antenna selected by the base station is set to a desired direction in each direction, and for separable users, a weighting factor of the array antenna having a low antenna gain is selected. For example, users A, B, and C exist, and A, B
Are adjacent to each other, the directions of A and B are assumed to be the desired directions for A and B, respectively.
, A weight coefficient of an array antenna having a low antenna gain is selected.

Next, as a second embodiment, it is possible to control the side lobe that is directed in a direction not intended for reception, which is a drawback of Algorithm 2, but that the calculation time is enormous. For the second approach to
This will be described in detail below.

The second method is based on the information that the desired direction and the interference suppression range and the antenna gain set in the interference suppression range are based on the side lobe having the low gain in the widest possible range in the interference wave direction. Deriving the weighting factor of the array antenna having the following, storing the derived weighting factor of the array antenna as data in a storage device, and sequentially using the data, the mobile station at an arbitrary location in the service area can be used. Apply the service.

Next, a second method for deriving the weight coefficient of the array antenna will be described below. At this time, for simplicity, the case where the number of users existing in the service area is 2 is handled.

Here, parameters required for the following algorithm are similar to those described above, and are as follows. First, let R be the service area range. here,
When the front direction of the array antenna is 0 degree, R = [− θ
_{Area to} θ _Area ]. The interference suppression range and R _u, the antenna gain in the interference wave suppression range and epsilon, gain difference provided between the gain (beta) for signals coming from the interference wave direction gain (alpha) with respect to the signal coming from the desired direction To (α−
β). These are values required from the system design.

Step 101: The desired direction is set to θ _d, and this is set to 0 degree using the origin as the origin. Set the interference wave suppression direction to θ _u
This is derived from the service area range R by one point (θ _u ∈R). Further, to set the range R _u containing theta _u as interference suppression range.

Step 102: Next, the algorithm 2 is used to derive the weighting factor of the array antenna based on the given θ _d , the interference wave suppression range, and the antenna gain ε in the interference wave suppression range.

Step 103: Weight coefficient w of array antenna
, The expected antenna gain is calculated. Where θ
_d Range p over which a gain greater than a certain value α can be obtained
And a gain below a certain value β centered on the interference wave suppression range
Examine the range q. Here, this relationship is expressed as w → [p, q]
It is described. If either p or q is empty,
Proceed to step 105. Also, the range of q is the same θ_d,θ_uUsing
Is smaller than q derived in the past.
Go to 5. Otherwise, the process proceeds to step 104.

Step 104: The correspondence between w and [p, q] is changed to w →
Described as [p, q]. The interference suppression range is increased by [Delta] R _u to return to step 102.

Step 105: Step 2 to Step 4
Of the weighting factors in the specific settings of θ _d and θ _u obtained by repeating the above, the weighting factor w → [p, q] having the maximum range of q obtained by increasing Δθ Store in table T.

Step 106: Returning to step 102, a new θ _u satisfying the following conditions is set, and the weight coefficient w _new of the array antenna is calculated. However, w _new shall satisfy the following conditions. {w _new → [p _new , q _new ] | ∀r: (r ∈ (q _new ∩¬ (q _new ∩Q))) ∈ (r ∈ R)}

Step 107: Step 2 to Step 6
Up to this point, a weighting factor corresponding to an arbitrary θ _u and focusing on a specific θ _d is recorded in T. Next, the unnecessary array antenna weighting factor w ′ recorded in T is erased by the same operation as in step 7 described above. However, w 'shall satisfy the following conditions. {w '→ [p', q '] | q'⊆q∈Q, w → [p, q], w', w ∈
T}

Step 108: When a desired station direction, that is, a direction in which directivity is directed, is focused on a specific θ _d , a range satisfying α is the most of the antenna gains obtained from the obtained weight coefficients of the array antenna. Focus on the smaller ones.
That is, among the values stored in P, the minimum value is a, and the range excluding a from R is _Rp . That is, a = m
When in (P), R _p ← (R _p- (R _p ∩a)). Next, θ _d {θ _d ∈R _p } is newly determined, and the process returns to step 102. Furthermore, repeat steps 8 steps 2 through R _p is empty.

Step 109: Unnecessary array antenna weighting factors w 'registered in table T are deleted. However, w 'shall satisfy the following conditions. {w '→ [p', q '] | (p'⊆p∈P) ∩ (q'⊆q∈Q), w →
[p, q], w ', w ∈T}

Step 110: end. In the table T, information on the effective array antenna weighting factor w and information on the antenna gain determined by w remains.

From the table T obtained in this way, a correspondence table and a weight table can be created. That is, the weighting coefficients of the array antenna can be derived in the case where the users can be separated by the operations from step 101 to step 110.

The features of the second technique have the same features as the features 1 to 9 of the first technique.

By using the above-described first and second techniques, a weighting coefficient of the array antenna and a correspondence table are completed. As described above, one of the requirements of the present invention is to provide a predetermined condition for the maximum gain of the antenna in a limited range and to control the array antenna using a weight coefficient vector satisfying this condition. is there.

By using the above method, Algorithm 1 does not require complicated calculations in an actual operating environment, and can derive a weighting factor for an array antenna having a wide range of interference wave suppression effects.

In addition, by using the above-described method of storing these in a storage device as a weight coefficient table and a correspondence table of an array antenna and referencing them when necessary, Algorithm 2 can be used in an actual operating environment. It is possible to derive an optimal array antenna weighting factor without requiring complicated calculations. Normally, when the calculation is performed by applying the algorithm 2, it is time-consuming to control the array antenna in real time by calculating using a current general computer, which is an operational obstacle. .

Further, by using the above method, it is immediately determined whether or not the weighting factor of the array antenna satisfying the requirement regarding the communication quality can be derived for the position of the mobile station using the results of the algorithms 1 and 2. it can. In the conventional method, even if the weight coefficient of the array antenna can be derived, it is determined whether the obtained weight coefficient of the array antenna is applicable.
difficult. This is because, even when the gain difference between the interference direction and the desired direction cannot be sufficiently obtained, the weight coefficient is derived as a calculation output using the conventional method. This is because confirmation work is required.

Therefore, a plurality of antenna weighting factors are determined in advance, and the weighting factors of these array antennas are stored as a table on the base station side, and the weighting factor of the corresponding array antenna is determined according to the position of the mobile station. The present invention proposes a method of referring to. More specifically, the method follows the following procedure.

(1) A predetermined condition is set for the maximum gain of side lobes within a limited range, and a plurality of weighting factors of the array antenna satisfying this condition are determined in advance and stored in the weighting factor table of the array antenna. . On this occasion,
Assuming a mobile station located at an arbitrary position in an area where the base station is to be serviced, a weight coefficient of an array antenna that can cope with any case is prepared. In addition, a correspondence table is prepared for associating the weight coefficient of each array antenna with an arrangement indicating what kind of state is applicable to the arrangement of the base station and the mobile station and the weight coefficient table of the array antenna.

(2) Referring to the correspondence table from the position information on the mobile station, it is determined whether or not spatial separation is possible.
If possible, the weighting factor of the array antenna is selected from the above-mentioned weighting factor table of the array antenna based on the information in the correspondence table. If it is not possible, take a predetermined action. For example, measures such as combining with another multiple access system are taken. (3) The array antenna is controlled using the weight coefficient of the selected array antenna. (4) After a predetermined time, the location information of the mobile station is updated, and the process returns to (2).

Hereinafter, an embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG. In these figures, substantially the same components or components having the same functions are denoted by the same reference numerals and described. In addition, a plurality of mobile stations that have no main beam control error as viewed from the base station are regarded as substantially a single mobile station.

FIG. 1 is a block diagram showing a configuration of an array antenna apparatus according to an embodiment of the present invention. The apparatus shown in FIG. 1 includes an array antenna 1, an array element 2, frequency conversion means 3, a reception intermediate frequency signal (or baseband signal) 4, a radio wave arrival direction estimation means 5,
Received signal azimuth 6, transmission / reception weight coefficient determination means 7, correspondence table 8, array antenna weight coefficient table 9, transmission weight coefficient 10, weight adjustment means 11 for each array element, reception weight coefficient 12, and received signal synthesis Means 13 are provided. Here, the receiving antenna and the transmitting antenna may use the array antenna 1 in common.

The operation of the directivity control antenna device will be described below with reference to FIG. An incoming radio wave is received by an array antenna 1 using M (M> 1) antennas as an array element 2. The reception frequency conversion means 3 converts the radio frequency of reception at each array element 2 of the array antenna 1 into an intermediate frequency signal (or baseband signal) 4.
The arrival direction estimating means 5 estimates the azimuth 6 of the received signal using the received intermediate frequency signal (or baseband signal) 4. The transmission / reception weight coefficient determination means 7 transmits a signal for directing a peak of directivity to a signal coming from each mobile station based on the estimation result of the arrival direction estimation means 5, the correspondence table 8 and the weight coefficient table 9 of the array antenna. Outputs a credit weighting factor of 10,
Weight adjustment means 11 adjusts the weight of each array element.
Also, for each of the received signals generated from each mobile station, a weighting coefficient for reception 12 is output. Received signal combining means 13
Performs the reception directivity synthesis on the signal generated from each mobile station by performing weighting synthesis processing on the reception intermediate frequency signal (or baseband signal) 4 using the reception weight coefficient 12. .

The above-mentioned array antenna weight coefficient table is set so as to cover the service area range required for the system and to satisfy the gain difference for signals coming from the desired direction and the interference wave direction. It is obtained using the proposed method 2. FIG. 2 is shown as a specific example. FIG. 2 shows method 2 for algorithm 2.
The use, the range R is 60 ° -60 °, the interference suppression minimum range R _u and 20 degrees, alpha = -3, using beta = -43.

Next, a correspondence table for selecting the weight coefficient of the array antenna will be described. FIG. 4 shows which directivity pattern among the directivity patterns A to N (A) to (N) shown in FIGS. 2 and 3 having the weighting factor of each array antenna when the number of mobile stations is two. It is an example of a correspondence table for determining whether to assign a pattern. This correspondence table is created based on an example of the directivity pattern of the array antenna 1 formed by the array antenna weighting factors stored in the array antenna weighting factor table 9 of FIG. Specifically, FIGS. 2 and 3
Are plotted on the horizontal axis (in this case, -3d
B), the vertical axis is a range given below a given given antenna gain (here, -43 dB),
The area is shown in FIG. Although FIG. 4 shows a two-dimensional diagram for the sake of clarity, it may be summarized as a numerical table. The method of reading in FIG. 4 is such that by reading the horizontal axis as the angle in the direction of the target mobile station and reading the vertical axis as the angle in the direction of the interfering mobile station, only the directions of the direction of the target mobile station and the direction of the interfering mobile station are used as input values. A set of weighting factors of the array antenna is found from combinations A to N (A) to (N) of the weighting factors of the array antenna of FIGS. 2 and 3. FIG.
The blank portion in indicates that the two mobile stations cannot be separated. By storing in this way, it is possible to immediately judge that spatial separation cannot be achieved by inputting only the directions of two stations. If separation is not possible in this way, it must be combined with other multiple access schemes. Therefore, the derivation of the weight coefficient of the array antenna in this case does not need to consider the interference wave. For example, user 1 is 40 degrees, user 2
Is present at 60 degrees, there is no corresponding array antenna weighting factor in FIG. Thus, for the user 1, any one of the array antenna weighting factors, G, I, J, K, L, M, N, etc., whose horizontal axis satisfies 40 degrees is selected. For the user 2, one of K, L, and M is selected.

A method of using the weighting factor selecting means of the array antenna will be described below with reference to FIG. FIG. 4 is a diagram for associating the position of the mobile station with the weight coefficient of the array antenna stored in the weight coefficient table 9 of the array antenna when two mobile stations are targeted. For example, 0
When a mobile station exists in the 0 degree direction and the 40 degree direction, when receiving a signal of the 0 degree direction mobile station, a set A of weighting coefficients of the array antenna derived from 0 degree on the horizontal axis and 40 degrees on the vertical axis is used.
Select When receiving a signal from a mobile station in a direction of 40 degrees, one of the sets G, K, and N of the array antenna weighting factors derived from the horizontal axis at 40 degrees and the vertical axis at 0 degrees is selected. Either can be selected, but this point is desirable because the center of the area of the set G of the weighting factors of the array antenna is closest to the point of 40 degrees on the horizontal axis and 0 degrees on the vertical axis. When the same frequency is used for transmission and reception, the weighting factor of the receiving array antenna is the same as the weighting factor of the transmitting array antenna. When different frequencies are used for transmission and reception, they are prepared separately. In this manner, by selecting and referencing the weight coefficient of the array antenna from the weight coefficient table 9 of the array antenna, it is not necessary to calculate each time, and the time spent for setting the weight coefficient of the array antenna can be reduced.

FIG. 5 shows the effect of the proposed means. FIG.
In (a), there are two mobile stations A and B (using the same frequency or very close frequencies), and a signal transmitted from the mobile station B to the base station is reflected, and as seen from the base station. , A plurality of signals apparently arrive from the direction of the mobile station B. If the direction where mobile station A is located is 0
And the direction in which B is located is assumed to be 40 degrees. When the base station extracts only the signal coming from the mobile station A, as shown in FIG. 4B, in the conventional method, there are very many interference waves (signals coming from directions other than the mobile station A) at the receiving station. In some cases, the number of signals that could be removed was limited. This is because the number of interference waves for which interference suppression can be performed is limited when the algorithm 1 type technique is used. However, when the proposed method is used, it is possible to remove an interference signal coming from a wide range as shown in FIG. This is because the present method aims to perform interference suppression over a wide range, and within this range, interference wave suppression can be performed without limitation on the number of interference waves.

Next, a case where there is an error in estimating the direction of the mobile station will be described. FIG. 6 is a diagram for comparing and explaining a case using the conventional control method and a case using the control method of the present invention when there is such an error. FIG. 5A shows a case where there are two mobile stations A and B, and the base station side knows the direction of each mobile station. FIG. 6B shows a directivity pattern of an array antenna according to a conventional control method. Here, suppose that the base station occupies the mobile station A in the direction of 0 ° and B exists in the direction of 40 °, but the base station erroneously changes the direction of the mobile station A in the direction of 5 ° and the direction of the B Is determined to be 45 degrees. Even with such a small direction estimation error, in the conventional method, when the base station extracts only the signal coming from the mobile station A, the antenna gain for the signal from A hardly changes, but the gain for the interference wave coming from B is reduced. Since the range that can be set low was narrow, it was difficult to remove the interference signal. However, according to the control method of the present invention, as shown in FIG. 6C, by preparing a weight coefficient of an array antenna capable of removing interference over a wide range, the interference signal can be removed even if there is some error. Becomes possible. Conventionally, the weighting factor of the array antenna in which the direction of the mobile station B is a null point is applied. On the other hand, according to the present invention, a side lobe is applied to a wide range around the arrival direction of a signal that should not be received. The reason for this is that the peak of is received using the weight coefficient of the array antenna having a sufficiently low gain.

Next, a method of selecting a weight coefficient of an array antenna according to the movement of a mobile station will be described. FIG. 7 is a diagram illustrating a method of selecting a weight coefficient of an array antenna according to movement of a mobile station. In FIG. 7A, two mobile stations A,
FIG. 7 shows a case where B exists and is moving respectively.
(B) shows a correspondence table prepared in advance in this case. Assuming that the direction in which the mobile station A is located is 40 degrees and the direction in which the mobile station A is located is -35 degrees, the optimal weight for the mobile station A is:
As shown in FIG. 6B, four patterns (I, L, M, N)
Exists. Taking the moving directions of the mobile stations A and B into consideration,
The weighting factor of the array antenna is selected as follows.
When mobile station A moves in the + direction: M is selected, and when mobile station A moves in the − direction: I is selected, and mobile station B
When moving in the direction: select N, when mobile station B moves in the-direction: select I, when mobile station A moves in the + direction, and when mobile station B moves in the + direction: L When the mobile station A moves in the + direction and the mobile station B moves in the-direction: I or M is selected (judging from the speed difference, mobile station A
If mobile station B is faster, select M, if mobile station B is faster, select I), mobile station A moves in the-direction, and mobile station B moves in the + direction: select I or N ( Judging from the speed difference, if the mobile station A is faster, select I; if the mobile station B is faster, select N), the mobile station A moves in the negative direction, and the mobile station B moves in the negative direction. Case: I is selected.

As described above, by preparing a plurality of weighting factors of the array antenna that can be selected according to the location of the mobile station, the optimum weight can be selected based on the movement information, and the optimum array antenna that follows the movement of the mobile station can be selected. Can be selected, and the number of times of changing the weight coefficient of the array antenna on the base station side can be reduced.

Next, when a device error is considered,
The adjustment of the weight coefficient of the array antenna will be described. FIG. 8 is a diagram for explaining the adjustment of the weight coefficient of the array antenna when the error of the device constituting the weight adjustment unit 11 or the reception signal combining unit 13 in the above embodiment is considered. FIG. 8 (a) shows the reception signal synthesizing unit 13 or the array antenna weight coefficient adjusting unit 11 or the reception directivity synthesizing unit 13 and the frequency conversion unit 3 and the array element 2 when generating the pattern A of FIG.
FIG. 7 is a diagram showing a change in directivity pattern when a phase error within two degrees exists in accordance with the power supply path up to the power supply path. FIG. 8 (b) shows the received signal combining means 13 or the weighting coefficient adjusting means 11 for the array antenna or the receiving directivity combining means 13, the frequency conversion means 3 and the feed path to the array element 2 in 3%. FIG. 9 is a diagram illustrating a change in directivity pattern when an amplitude error exists. FIG. 8C shows the phase within one degree in accordance with the power supply path to the reception signal combining means 13, the array antenna weight coefficient adjusting means 11, the reception directivity combining means 13, the frequency converting means 3 and the array element 2. FIG. 9 is a diagram illustrating a change in directivity pattern when an error and an amplitude error within 3% exist.

As shown in FIGS. 8 (a) and 8 (b), the directivity pattern is repeatedly calculated in a state where an error such as a signal transmission path is given in the weight coefficient of each array antenna, and the characteristic is examined. With a certain error, it is possible to calculate what percentage of the probability that a certain gain can be guaranteed. By creating a correspondence table using this information, it is possible to prepare an array antenna weighting coefficient in which the influence of the error is reduced, and to select it when using it.

Next, an example will be described with reference to FIG. 8 in which the tolerance for the device error is examined by using the array antenna weighting factor stored in the array antenna weighting factor table. FIG. 8A shows the reception signal combining means 13.
Alternatively, it is also possible to adjust the length of the power supply to the reception directivity synthesis means 13, the frequency conversion means 3 and the
FIG. 3 is a diagram illustrating a change in a directivity pattern in a combination A of weighting factors of the array antenna illustrated in FIG. 2 when a phase error within a degree exists. This figure shows that it is possible to maintain -40 dB or less with a probability of 95% or more. Also,
FIG. 2B shows a case where an amplitude error of 3% or less exists along the power supply path to the reception signal synthesizing unit 13 or the reception directivity synthesizing unit 13 and the frequency conversion unit 3 and the array element 2. FIG. 8 is a diagram showing a variation in directivity pattern in a combination A of weighting factors of an array antenna. This figure also shows that 95% or less can be maintained at -40 dB or less. FIG. 4C shows a phase error within 1 degree and an amplitude error within 3% in accordance with the power supply path to the reception signal synthesizing means 13 or the reception directivity synthesizing means 13 and the frequency conversion means 3 and the array element 2. FIG. 3 is a diagram showing a change in directivity pattern in a combination A of weighting factors of the array antenna shown in FIG. This figure also shows that 95% or less can be maintained at -40 dB or less. In other words, a correspondence table is created by using information that, with respect to the weighting factor of each array antenna stored in the weighting factor table of the array antenna, it is possible to maintain the gain below a specific gain with a probability of more than what percentage. Thereby, tolerance for an error can be given.

Conversely, the tolerance for an error to secure a specific gain at a certain probability or higher can be examined.
It is possible to specify an upper limit of a device error for guaranteeing a desired antenna directivity.

[0108]

Since the present invention has the above-described configuration,
The following effects can be obtained.

According to the first aspect of the present invention, the gain of the array antenna can be suppressed to a low level with respect to an interference wave in a wide range.

According to the second aspect of the present invention, it is possible to determine in a short time whether or not the gain of the array antenna can be suppressed to a low level with respect to an interference wave in a wide range during the operation of controlling the antenna. It became so.

According to the third aspect of the present invention, the apparatus has a desired antenna gain in a desired direction and a low antenna gain in a direction of an interference wave without having a complicated arithmetic processing capability. The array antenna characteristics can be obtained in a short time, and it can be determined immediately whether two or more users can use the same frequency. Further, since the interference wave suppression range can be set wider than the conventional method, there is an advantage that the tolerance for the DOA estimation error is high.

According to the fourth aspect of the present invention, in addition to the effects of the first aspect of the present invention, a desired device can be provided in response to a change in a mobile station without having a complicated arithmetic processing capability of the apparatus. Array antenna characteristics with a desired antenna gain in the direction and a low antenna gain in the direction of the interference wave,
It can be derived in a short time.

Further, according to the fifth aspect of the present invention, even if a device having an error is used, an array antenna characteristic having a sufficiently low antenna gain in the direction of an interference wave can be obtained in a short time.

Furthermore, in the invention according to claim 6, since the destination of the mobile station is predicted and the weight coefficient of the array antenna is prepared, it is substantially short in a short time and is sufficiently low in the direction of the interference wave. Array antenna characteristics having antenna gain can be obtained.

Further, according to the inventions set forth in claims 7 and 8, from among the plurality of array antenna weighting factors, an optimum one is selected according to the communication conditions, and the weighting factor is sufficiently short in the direction of the interference wave in a short time. An array antenna characteristic having a low antenna gain can be obtained.

Further, according to the ninth aspect of the present invention, even when the weighting factor of the first array antenna cannot be applied, the suboptimal method is applied by applying the weighting factor of the second array antenna. Can be.

Further, according to the tenth aspect of the present invention, the array antenna characteristics having a sufficiently low antenna gain in the direction of the interference wave can be obtained in a short time in accordance with the movement of the mobile station.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a directivity control antenna device according to an embodiment.

FIG. 2 is a diagram showing an example of an array antenna directional pattern formed by array antenna weight coefficients stored in an array antenna weight coefficient table;

FIG. 3 is a diagram illustrating an example of an array antenna directional pattern formed by array antenna weighting factors stored in an array antenna weighting factor table;

FIG. 4 is a diagram showing an example of a correspondence table.

FIGS. 5A and 5B are schematic diagrams illustrating effects of the present invention, and FIG. 5A is a schematic diagram illustrating an arrangement of a base station and two mobile stations A and B;
(B) is a diagram showing a directivity pattern by a conventional control method, and (c) is a diagram showing a directivity pattern by a control method of the present invention.

FIG. 6 is a schematic diagram for explaining the effect of the present invention when there is an error in estimating the direction of the mobile station;
(A) is a schematic diagram showing a case where the directions of the mobile stations A and B are erroneously estimated on the base station side, (b) is a diagram showing a directivity pattern of an array antenna by a conventional control method, and (c) is a diagram. FIG. 4 is a diagram illustrating a directivity pattern according to the control method of the present invention.

7A and 7B are diagrams showing a method of selecting a weight coefficient of an array antenna according to movement of a mobile station, wherein FIG. 7A shows two mobile stations A,
B is a diagram showing a case where there is, and each is moving,
(B) is a diagram showing a correspondence table prepared in advance.

FIG. 8 is a diagram for explaining adjustment of a weight coefficient of an array antenna in consideration of a device error; FIG. 8 is a diagram illustrating a reception signal combining unit 13 or a weight coefficient adjusting unit 11 of an array antenna, a frequency conversion unit 3, (A) is a diagram showing the variation of the directivity pattern when there is a phase error within 2 degrees in each of the power supply paths to element 2.
(B) is a diagram showing the variation of the directivity pattern when there is an amplitude error of 3%, and (c) is a diagram showing the case where a phase error of less than 1 degree and an amplitude error of less than 3% exist. FIG. 6 is a diagram illustrating a change in a directivity pattern.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Array antenna 2 Array element 3 Frequency conversion means 4 Intermediate frequency signal (or baseband signal) of reception 5 Arrival direction estimation means 6 Direction of reception signal 7 Transmission / reception weight coefficient determination means 8 Correspondence table 9 Weight coefficient table 10 Transmission weight coefficient DESCRIPTION OF SYMBOLS 11 Weight adjustment means 12 Weight coefficient for reception 13 Received signal synthesis means

Continuation of the front page (72) Inventor Hiroyo Ogawa 3-4 Hikarinooka, Yokosuka City, Kanagawa Prefecture F-term (reference) 5J021 AA05 AA06 CA06 DB02 DB03 EA04 FA14 FA15 FA16 FA17 FA18 FA20 FA24 FA26 FA32 GA02 GA06 HA04 HA05 HA07 5K059 CC03 CC04 5K067 AA03 CC24 EE02 EE10 EE22 GG11 HH21 HH23 KK02 KK03

Claims (10)

[Claims] 1. A procedure for adjusting the main lobe direction so as to include a substantially single radio wave source of a radio wave to be received, and a predetermined antenna gain or less within a predetermined radio wave arrival direction range. A method of controlling the maximum antenna gain in each side lobe and a procedure of adjusting the range so as to include a radio wave source that should not be received. 2. A method for controlling the directivity of an array antenna according to claim 1, wherein a table for associating a main lobe direction with a coverable direction of a side lobe direction is to be received with reference to the table. Determining whether the direction of arrival of the radio wave can be directed to the direction of the main lobe and the direction of the side lobe can be directed to the direction of arrival of the radio wave that should not be received. Directivity control method. 3. A predetermined condition is set for a maximum gain of a plurality of side lobes within a limited range, and a plurality of weighting factors of an array antenna satisfying the condition are determined in advance.
A procedure for storing this in a predetermined manner, and a procedure for preparing a correspondence table for associating the arrangement of the base station, the arrangement of the mobile stations, and the array antenna weight coefficient table with respect to each of the above-mentioned weight coefficients. And, from the location information about the mobile station, refer to the above correspondence table, determine whether the radio wave to be received and the radio wave to avoid reception are spatially separable or impossible, and if possible, the information in the correspondence table If a weight coefficient is selected from the weight coefficient table of the array antenna based on the above, if it is not possible, a procedure for taking a predetermined correspondence, and a procedure for controlling the array antenna using the selected weight coefficient, And a directivity control method for an array antenna. 4. A procedure in which a predetermined condition is set for a maximum gain of a plurality of side lobes within a limited range, a plurality of weighting factors satisfying the condition are determined in advance, and stored in a predetermined method. Each weighting factor is a procedure for preparing a correspondence table for taking correspondence between the arrangement of the base station and the arrangement of the mobile station, and the weighting factor table of the array antenna. To determine whether the radio wave to be received and the radio wave to avoid reception are spatially separable or impossible.If possible, the weighting factor is calculated from the weighting factor table of the array antenna based on the information in the correspondence table. If it is not possible, a procedure for taking a predetermined correspondence, a procedure for controlling the array antenna using the selected weighting factor, and after a predetermined time, the position of the mobile station Update information Again, from the position information on the mobile station, referring to the correspondence table, determine whether the radio wave to be received and the radio wave to avoid reception are spatially separable or impossible, and if possible, the information in the correspondence table And selecting a weighting factor from the weighting factor table of the array antenna based on the above, and if not possible, returning to a procedure for taking a predetermined correspondence. Method. 5. The directivity control method for an array antenna according to claim 3, wherein an arrival direction of a signal to be received by the array antenna and an arrival direction of a signal not to be received are generated from characteristics of the device. A directivity control method for an array antenna, comprising a procedure for determining a weight coefficient of the array antenna so as to compensate for a decrease in antenna gain due to an error. 6. The array antenna directivity control method according to claim 3 or 4, wherein the weighting factor of the array antenna at a representative point in a region where the mobile station moves indicates the direction of arrival of the signal to be received and the direction of arrival of the signal to be received. A directivity control method for an array antenna, comprising a procedure prepared before communication with information on the direction of arrival of a non-signal, stored by a storage means, and utilizing information stored in the storage means during communication. 7. The array antenna directivity control method according to claim 6, wherein a plurality of array antenna weight coefficients at at least one representative point are prepared prior to communication, and each array antenna weight coefficient is stored in a storage unit. A directivity control method for an array antenna, comprising a procedure of selecting and utilizing a plurality of weighting factors stored in the storage means during communication and according to the situation. 8. The directivity control method for an array antenna according to claim 6, wherein the weighting factor of the array antenna according to the situation is determined from the weighting factors of the plurality of array antennas stored in the storage means during communication. A method for controlling directivity of an array antenna, comprising: a procedure for determining whether or not a weight coefficient of the array antenna for maintaining a constant communication quality is stored in its storage means. 9. The directivity control method for an array antenna according to claim 8, wherein the determining step does not select the first array antenna weighting factor stored in the storage means. A directivity control method for an array antenna, comprising a procedure for selecting a second weighting factor for setting an antenna directivity capable of covering a plurality of mobile stations. 10. The directivity control method for an array antenna according to claim 9, wherein the information stored in said storage means at the time of communication is utilized by utilizing the movement information of the mobile station as prediction information. A directivity control method for an array antenna, comprising a procedure for predicting and selecting a weight coefficient of the array antenna stored in the storage means.