JP3423375B2 - Antenna coupling device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [0001] This invention relates to multipath fading.
Antenna coupling device that removes interference waves caused by
I do. [0002] 2. Description of the Related Art In land mobile communications, especially in urban areas.
In this case, multipath fading occurs and communication quality is reduced.
Deteriorate. During such multipath fading,
To remove interference waves using multiple antennas
CMA (Constant Modulus Alg)
orithm) is described in, for example,
Hei 3-70216, "Fujimoto, Kikuma, Inagaki:" Ma
Multiple Waves of CMA Adaptive Array Using Leucate Method
Suppression Characteristics ", IEICE Transactions B-2, Vol. 74
11, No. 559-607, 1991 ".
ing. [0003] An application of the CMA described in
The tenor coupling device adds a coefficient to the signal received from each antenna.
Are multiplied by each other, and the result of the multiplication is combined as an antenna output.
Output, and for each coefficient, the output of the result of multiplication becomes constant.
Adaptive control, and a constant output for adaptive control.
The value obtained by multiplying the signal based on the error
I am trying to return to. If the value of the feedback coefficient μ is increased, the
Convergence (removal of interference waves), but stable after convergence
This causes a phenomenon in which the characteristics are poor (the interference wave removing characteristic is deteriorated). [0005] As described above, the conventional
Increase the feedback coefficient μ in the antenna coupling device
And the convergence becomes faster, but the stability becomes worse.
The convergence slowed down but the stability improved. The present invention has good convergence and good stability.
An object of the present invention is to provide an antenna coupling device. [0007] Means for Solving the Problems To solve the above-mentioned problems,
The means employed by the present invention will now be described. Multiple antennas
Is multiplied by the coefficient, and the output of combining the multiplication results is
Antenna generated by adaptively controlling each coefficient to be constant
In the coupling device, an error of the combined output from a fixed value is considered.
An output error detection unit that detects a difference, and generates each of the coefficients.
Signal A generating a feedback signal with fast convergence for
And a stable feedback signal for generating the coefficients.
A feedback signal B generator for generating a signal;Generation of the feedback signal A
Signal generated by the feedback signal generator B and the signal generated by the feedback signal generator B.
And the error value detected by the output error detection unit is large.
When the signal from the feedback signal A generating section is large,
When the error value is small, the signal from the feedback signal B becomes large.
Feedback based on the error value
A synthesis unit;Is provided. [0008] [Operation] The output error detecting section calculates a fixed value of the combined output.
Is detected and output. In the feedback signal A generator,
A fast convergent feedback signal is generated to generate the number
You. In the feedback signal B generator, each coefficient is generated.
A stable feedback signal is generated. Return
In the component section, the signal generated by the feedback signal A generation section and the feedback signal B
The signal generated by the generator is detected by the output error detector.
When the error value is large, the signal from the feedback signal A generator is increased.
When the error value is small, the signal from the feedback signal B
The signals are divided and combined based on the error value so that the signal becomes large. As described above, the feedback for generating each coefficient is as follows.
Return signal with fast convergence and stable 2-feedback signal
If the error of the combined output is larger than a certain value,
Fast convergence feedback signal and stable when error is small
Proportional feedback signal based on error value
So that convergence is fast and stable.
be able to. [0011] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS.
explain. FIG. 1 is a block diagram of an embodiment of the present invention, and FIG.
It is a specific example of a multiplication part and a coefficient generation part of an example. In FIG.
Here, 1 is an antenna, 2 is a frequency converter, and 3 is a local oscillator.
Vibrator, 4 is 90-degree phase shifter, 5 is analog-to-digital conversion
, 6 is a multiplier, 7 is a coefficient generator, 8 is an adder, and 9 is an output.
Force error detector, feedback signal A generator 10, feedback signal A
The signal B generator 12 is a feedback synthesizer. In the embodiment, four antennas 1 are provided.
A case is shown, which is generally composed of n pieces. Each en
The received signal from the antenna is divided into two equal parts,
To the converters 2A and 2B. The frequency converter 2A receives a signal from the local oscillator 3
The output, and 9 to the frequency converter 2B at the 90 degree position 4
The frequency conversion is performed by inputting a signal that is
You. That is, the outputs from the frequency converters 2A and 2B
The signals are output as signals orthogonal to each other. Each of the frequency-converted signals is
Digital converter (A / D) 5A and 5B
Is converted into a signal. Hereafter, at A / D5A and 5B
To explain the converted signal as a pair,
Tor display. That is,       X₁= X_1I+ Jx_1Q                                      … (1) Where X₁Is the signal of antenna # 1 system x_1IIs the in-phase component of antenna # 1 x_1QIs the quadrature component of antenna # 1 Expressed by Next, in order to facilitate the operation of the embodiment,
The adaptive control of the coefficient of the CMA will be described with reference to FIG.
You. In FIG. 2, a multiplication unit 6, an addition unit8And coefficient generation
Department7Is as described in FIG. The multiplying unit 6 comprises a multiplier 61. coefficient
The generation unit 7 includes a coefficient memory 71, a subtractor 72, and a multiplier.
73. For ease of explanation, the feedback signal A
The output of the generator 10 is used to generate coefficients without passing through the feedback synthesizer 12.
Department7The following explanation will be made assuming that the
Corresponding to the antenna coupling device). There are four systems corresponding to each antenna.
However, since the operations are all the same, only one system will be described.
In the multiplier 61, the signal X expressed by the equation (1)₁(K)
Number memory71Coefficient H recorded in₁Multiplication with (k)
And adder8Output to Ie       X₁(K) H₁(K) = [Y₁(K)] ... (2)         Where X₁(K) is the k-th sample value                 H₁(K) is the coefficient value for the kth [Y₁(K)]. Adder8Now, the result multiplied by the multiplication unit 6 is
Combine. That is,   Y (k) = [Y₁(K)] + [Y_Two(K)] + [Y_Three(K)] +             [Y_Four(K)] ... (3) Is performed and Y (k) is output. Y (k) represented by the equation (3) is an antenna.
It is output as a received signal of the antenna. Equation (3)
Arithmetic part8Output Y (k) is taken into the feedback signal A generator 10
It is. In the feedback signal A generator 10, first, the in-phase of Y (k)
Component y_IAnd the orthogonal component y_QSquare operation for each of
To perform addition. That is,   | Y (k) |^Two= (Y_I(K))^Two+ (Y_Q(K))^Two          … (4) And the square value | Y of the amplitude of the signal Y (k)
(K) |^TwoAsk for. Next, 1 is subtracted from the addition output.
The error e (k) from the constant value output is calculated. Sand
Chi     e (k) = (y_I(K))^Two+ (Y_Q(K))^Two-1             = [| Y (k) |^Two-1]… (5) Is calculated. Subsequently, the error e (k) is multiplied by Y (k).
You. That is,   [| Y (k) |^Two-1] Y (k) = e (k) Y (k) (6) Is performed. On the other hand, the input signal X₁Take the conjugate of (k).
That is,     X₁ ^C(K) = [x_1I(K) + jx_1Q(K)]^C                 = X_1I(K) -jx_1Q(K) ... (7) Where X^cRepresents the conjugate of X. Perform the following processing,
Invert the sign of the orthogonal component. In the feedback signal A generator 10, the result of equation (6) is obtained.
The result is multiplied by the result of Expression (7) to output a feedback signal A.
That is,   A₁(K) = e (k) Y (k) X₁ ^C(K) ... (8) Is output. In the second system, X in Expression (8)
₁ ^CX in place of (k)_Two ^C(K) is multiplied by A
_Two(K) is output. Coefficient generator7Coefficient memory 71
The (k + 1) th coefficient value H₁(K + 1) is H₁(K)
The feedback signal A represented by the equation (8) is multiplied by a multiplier.7The feedback coefficient μ at 3
Is rewritten to a value obtained by subtracting the result of multiplying by. That is,   H₁(K + 1) = H₁(K) -μe (k) Y (k) X₁ ^C(K) ... (9) H₁Is rewritten to the value of (k + 1) and the next data X
₁The multiplication with (k + 1) is repeated. The coefficient H is, as apparent from the equation (9),
When the feedback coefficient μ is set to a small value, the second term of Expression (9) becomes
What happens before the value of coefficient H reaches steady state
It has to be repeated several times, and the convergence deteriorates. But,
When the feedback coefficient μ is reduced, e (k) and
Y (k) and X^CEven if the value of (k) changes significantly,
The change in the value of the number H is small and operates stably. In the present invention, the feedback coefficient μ is set to a large value to converge.
The stability is improved and the stability is determined by the means described later.
Has been improved. In addition, the operation described above
The reason why the radiation is removed is that the coefficient H is adaptively controlled by the multiplier 6.
And multiply and combine with the received signal of each antenna.
Beam from multiple antennas in the direction of arrival of the reflected wave.
Of the reflected wave direction
The reflected wave is eliminated by reducing the antenna gain of the antenna. Note that, using the feedback signal A shown in the equation (8),
The method of rewriting the coefficient value H as shown in equation (9) is the fastest.
This is a method called the laying method. Next, to improve stability
explain about. As mentioned earlier, the steepest gradient occurs
If the coefficient H is generated based on the feedback signal A
Fast bundle, but poor stability. The feedback signal generated by the feedback signal B generator 11
Signal B has poor convergence but generates a stable feedback signal
Let it. As a feedback signal with poor convergence but good stability
Is, for example, the generation of a return signal called Newton-Gauss.
There is a formula. The feedback signal B generator 11 uses this method.
A feedback signal B is generated. That is,   B₁(K) = e (k) / [Y (k) X₁ ^C(K)] ... (10) Generate. In equation (10), e (k) is
(5), Y (k) is the output of the adder 8, X₁ ^C(K) is the formula
Given by (7). For the second system, X in Expression (10)
₁ ^CX in place of (k)_Two ^C(K) is multiplied by B
_Two(K) is output. On the other hand, in the output error detection unit 9,
The error e (k) is calculated from the constant value of the output Y (k) of the adder 8
Error e_aIs output. That is,   e_a= | E (k) | + | e (k + 1) | +         ... + | e (k + n) | ... (11) Is output. In equation (11), e (k) is calculated by equation (5)
Since e (k) takes positive and negative values,
The error e is obtained by adding n absolute values of_aOutput as Return
In the synthesizing unit 12, the error output from the output error detecting unit 9
from e   α = 1 / (1 + e_a…… (12) Is calculated to calculate the prorated coefficient α. When the proportional coefficient α is calculated, the feedback signal A is generated.
For the feedback signal A (k) output from the raw unit 10,
(1-α) is output from the feedback signal B generator 11.
The feedback signal B (k) is multiplied by α and synthesized.
Coefficient generator7Output to Therefore, the coefficient memory 71
Is the (k + 1) th coefficient value H (k + 1)   H (k + 1) = H (k) -μ [(1-α) A (k) + αB (k)]               = H (k) -μ [(1-α) e (k) Y (k) X^C(K)                 + Αe (k) / (Y (k) X^C(K)] ... (13) Is rewritten to the value of H (k + 1)
The multiplication with (k + 1) is repeated. As is clear from equation (12),
α is the error e_aIs large, the value becomes small, and conversely, e_aBut
It approaches 1 when it gets small. Therefore, the second expression (13)
The term is the error e_aIs large, A (k) becomes dominant, and conversely
Error e_aIs small, B (k) becomes dominant. That is, the error e_aIs large and unconverged
The convergence is performed by the feedback signal A having good convergence, and the error
e_aIs small and converged, the feedback signal B with good stability
Is to be returned. In the embodiment, the output error
The number of errors output from the detector is n for the difference e from the constant power.
Addition value e of_aWas output, but the difference
You may make it output n addition values. The embodiment of the present invention has been described above.
However, the present invention is not limited to this embodiment.
Various modifications in accordance with the gist of the present invention are possible. [0038] As described above, according to the present invention,
The effect of is obtained. Feedback signal to generate each coefficient
Generates two feedback signals with fast convergence and good stability
Convergence when the error of the combined output is larger than a certain value.
Fast feedback signal and good stability when the error is small.
Feedback signal based on the error value
Convergence is fast and stable.
it can.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a configuration diagram of an embodiment of the present invention. FIG. 2 is a specific example of a multiplier and a coefficient generator according to the embodiment. [Description of Signs] 1 antenna 2 frequency converter 3 local oscillator 4 90-degree phase shifter 5 analog-to-digital converter 6 multiplier 7 coefficient generator 8 adder 9 output error detector 10 feedback signal A generator 11 feedback signal B generator Section 12 feedback synthesis sections 61 and 73 multiplier 71 coefficient memory 72 subtractor

────────────────────────────────────────────────── (5) References JP-A-3-70216 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01Q 3/26 H01Q 21/00 H04B 1 / Ten

Claims (1)

(57) [Claim 1] An antenna coupling apparatus which multiplies a signal from a plurality of antennas by a coefficient, and adaptively controls each coefficient so that an output obtained by combining the multiplication results to be constant, generates the antenna coupling apparatus. An output error detection unit that detects an error of the combined output from a fixed value; a feedback signal A generation unit that generates a feedback signal with high convergence for generating the coefficients; and generates the coefficients. Signal generator for generating a feedback signal having good stability, a signal generated by the feedback signal A generator , and the feedback signal generator.
The signal generated in the raw portion B is detected by the output error detecting portion.
When the error value obtained is large, the feedback signal A
Is large and the error value is small, the feedback signal B
So that a larger signal is obtained based on the error value.
An antenna coupling device , comprising: a feedback combining unit that separates and combines.