JPS6126253B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device that removes interference waves that cause interference in wireless communication on the receiving side.

A conventional device of this type is constructed as shown in Fig. 1, where 1 is a main antenna, 2 is an auxiliary antenna, and 3 is a main antenna.
4 is a synthesizer, and 5 is a correlation detector. The main antenna 1 is oriented in the direction of the desired wave, and other interference waves of the desired wave leak into it. The auxiliary antenna 2 is directed toward the interference wave source and receives only the interference wave. The interference wave received by the auxiliary antenna 2 is controlled by an amplitude phase control circuit 3 so that it has the same amplitude and opposite phase as the interference wave input to the main antenna 1.
Interference waves are removed by combining with the signal received by the main antenna 1. The control signal of this amplitude phase control circuit 3 is the output of the combiner 4 and the auxiliary antenna 2.
The correlation detector 5 obtains the correlation with the interference wave received at the . This correlation detector 5 conventionally stabilizes the input signal using a phase-locked loop (PLL) or the like against frequency fluctuations of the input signal, and then performs phase detection to obtain phase difference information. However, when using PLL, it works well for unmodulated signals, but
If there is no carrier component such as a PSK wave or FM wave, or if there is a carrier component but the spectrum is spread, the PLL will not synchronize and it will be difficult to obtain the required phase difference.

In order to eliminate these drawbacks, the present invention periodically separates the amplitude and phase of the interference wave received by the auxiliary antenna by obtaining the difference between the phase of the small fluctuation and the phase of the interference wave power fluctuation after compensation. Accordingly, the present invention provides an interference wave compensation device that suppresses interference waves.

The present invention will be explained in detail below.

FIG. 2 shows an embodiment of the present invention, in which 1 is a main antenna, 2 is an auxiliary antenna, 3 is an amplitude phase control circuit, 4 is a combiner, 6a, 6b are voltage integrators, 7 is a low frequency oscillator, 8a , 8b is an adder, 9 is a frequency converter, 10 is a bandpass waver, 11 is a signal amplifier, 12 is an envelope detector, 13 is an amplifier, 14 is a
90° phase shifter, 15a, 15b are phase detectors, 16
is the interference wave compensation output.

The amplitude and phase control circuit 3 can control amplitude and phase at the same time, and an example using a vector modulator will be described here. FIG. 3 shows a schematic configuration diagram of a vector modulator, in which 17 is an input terminal connected to the auxiliary antenna 2, 18 is a signal branch circuit, 19a, 19b, 19c, and 19d are fixed phase shifters, and 20a is a signal branch circuit. , 20b, 20c, and 20d are PIN attenuators; 21 is a signal combiner; 22a and 22b are input terminals for each control signal from the adders 8a and 8b; and 23 is an output terminal connected to the combiner 4.

In the circuit shown in FIG. 3, the input terminal from the auxiliary antenna 2 is branched into four systems by a signal branching circuit 18, and each has a fixed phase shifter 19a, 19b, 19.
c, 19d gives phase shifts of 0, π/2, π, and 3π/2. That is, the input signal is I _A e ^j(
〓 ^t+ 〓 ⁾ [where I _A : amplitude, Ω: input signal angular frequency, β: initial phase], the fixed phase shifter 19
The outputs of a, 19b, 19c, and 19d are as follows.

0 phase output: I _A /4e ^j( 〓 ^t+ 〓 ⁾ (1) π phase output: I _A /4e ^j( 〓 ^t+ 〓 ⁺ 〓 ⁾ =-I _A /4e ^j( 〓 ^t+ 〓 ⁾ (3) After this, use the PIN diode to connect the attenuator 20.
a, 20b, 20c, 20d, respectively
The output amplitude is controlled according to the current flowing through the PIN diode. These four signals are transferred to a signal synthesizer 21
Combine and output.

Figure 4 shows PIN attenuators 20a, 20b, 20c,
A vector diagram of each output of 20d is shown. In FIG. 4a, no current flows through each diode, and each attenuator 20a,
This is a case where the attenuation amount of 20b, 20c, and 20d is 0, and as is clear from the sum of equations (1) to (4), the vectors cancel each other out, and the vector modulator output becomes 0.
However, when the control voltage A is applied to the input terminal 22 connected to the attenuators 20a and 20c, if the control voltage A is a positive voltage, the A
A current proportional to flows, and the amount of attenuation increases. At this time, since the amplitude of the output of the attenuator 20a is attenuated in accordance with the control voltage A, the zero-phase vector 〓 ₁ becomes the following equation.

〓 ₁ = 1/4I _A (1-K _V A) e ^{j (} 〓 ^t+ 〓 ⁾ (1)' [However, K _V is the control gain] Therefore, Equations (1)', (2) to (4) From the sum of , only the π-direction component appears in the composite vector, and the output becomes -1/4K _V AI _A e ^j( 〓 ^t+ 〓 ⁾ . That is, by controlling the current flowing through the attenuator 20a or 20c depending on the positive or negative sign of the control signal, the vector in the 0 and π directions is controlled, and the vector in the 0 and π directions is controlled by the attenuator 20b or 20d. Controls vectors in two directions. As a result, the amplitude and phase of the vector modulator input terminal can be controlled and output as desired.

Next, an explanation will be given of an interference wave compensation device using this vector modulator.

First, the signal (interference wave) _A received by the auxiliary antenna 2 directed toward the interference wave source can be expressed as follows.

〓 _A = I _0A e ^j( 〓 ^t+ 〓 ⁾ (5) 〓 _A is input to the amplitude phase control circuit 3, and 0, π
The direction vector is the output A of the voltage integrator 6a and the output a cosωt of the low frequency oscillator 7 [where a is the amplitude,
ω is the output angular frequency of the low frequency oscillator 7] is added to the adder 8
It is controlled by the voltage (A+a cosωt) added by a. Similarly, the π/2 and 3π/2 directions are (B+a
It is controlled by sinωt. As a result, the vector modulator output 〓 _VM becomes the following equation.

〓 _VM = −K _V I _A {(A+a cosωt)+j(B+a sinωt)}e ^j( 〓 ^t+ 〓 ⁾ I _A ′e ^j( 〓 ^t+ 〓 ⁺ 〓 ⁾ (6) However, I _A = I _0A /4 (7) I _A ′ = −K _V I _A √(+ ) ² +(+
a sinωt) ² (8) φ=tan ^-1 (B+a sinωt/A+a cosω
t) (9) That is, 〓 _VM is P as shown in the vector diagram in Figure 5.
The tip of the vector rotates at the angular frequency ω so as to draw a circle with radius K _V aI _A around the point (-K _V AI _A , -jK _V BI _A ).

On the other hand, the interference wave 〓 _M received by the main antenna 1 directed toward the desired wave direction can be expressed as follows.

〓 _M =I _M e ^j( 〓 ^t+ 〓 ⁾ (10) When this 〓 _M and 〓 _VM are combined in the synthesizer 4, the following formula is obtained from formulas (6) and (10).

〓 _E =〓 _M +〓 _VM =I _M e ^j( 〓 ^t+a) +I _A ′e ^j( 〓 ^t+ 〓 ⁺ 〓 ⁾ =I ₀ e ^j( 〓 ^t+ 〓 ₀ ⁾ (11) However, I ₀ ² = {I _A ′ cos (β + φ) + I _M cos α} ² + {I _A ′ sin (β + φ) + I _M sin α} ² = I _M ² +K _V ² I _A ² (A ² +B ² +a ² )+2I _M I _A K _V {Acos(α+β)+Bsin(α−β)} ＋2K _V ² I _A ² a(Acosωt+Bsinωt)−
2I _M I _A K _V a cos (ωt−α+β) (12) φ ₀ =tan ^-1 {I _A ′ sin(β+φ)+I _M s
inα/I _A ′ cos(β+φ)+I _M cosα} (13) Composite vector = _E is R(A ₀ I _M
−K _V AI _A , j (B ₀ I _M −K _V BI _A )) [However, A ₀ = cos
(α−β), B ₀ =sin(α−β)] and draw a circle with radius K _V aI _A as the center. At this time, the output of synthesizer 4〓 _E
The length, that is, the amplitude of 〓 becomes the minimum when the tip of _E approaches the origin 0, and becomes the maximum when it moves away from the origin. This coincides when the vector modulator output 〓 _VM approaches and leaves the vector 〓 _M ', which has the same amplitude and opposite phase as the interference wave 〓 _M from the main antenna 1. That is, the _phase of the amplitude fluctuation of the vector _〓
K _V AI _A , −jK _V BI _A ) to the tip Q′ of 〓 _M ′ (−A ₀ I _M ,
−jB ₀ I _M ) has a phase difference of θ corresponding to the direction.

Therefore, the envelope detector 12 determines the amplitude of the output _E of the synthesizer 4. That is, considering only the real part of equation (11), the following equation is obtained.

K ₁ {Re(〓 _E )} ² = K ₁ I ₀ ² cos ² (Ωt + φ ₀ ) = K ₁ /2I ₀ ² {1−cos (2Ωt + 2φ ₀ )} (14) [However, K ₁ is from the synthesizer Gain up to the envelope detector in the subsequent stage] If this is removed by a bandpass filter or the like in the amplifier 13 to remove the twice the input terminal frequency component and the DC component, the output i _d of the envelope detector 12 is given by equation (12), 14), the following formula is obtained.

i _d =K ₁ I ₀ ² /2 =K ₁ {K _V2 I _A ² a(A cosωt +B sinω
t) −I _M I _A K _V a cos (ωt −α+β)} (15) However, in the embodiment shown in FIG. 2, the frequency is converted to an intermediate frequency by the frequency converter 9, and in order to avoid the influence of noise from other signals. Only the frequency component of the interference wave is extracted by a bandpass filter 10, amplified to an appropriate level by a signal amplifier 12, and then detected.

Next, the output of the envelope detector 12 is amplified to an appropriate level by the amplifier 13, and then the output of the low frequency oscillator 7 and a signal obtained by giving a 90° phase shift to this by the 90° phase shifter 14 are used. , phase detector 15a,
When phase detection is performed in 15b, the following equation is obtained.

K ₂ × i _d × a cosωt=K ₁ K ₂ K _V I _A a ² /2 [K _V I _A (A-Acos2ωt +Bsin2ωt) I _M {cos (2ωt-α+β)-cos (-α+β)}] ( 16) [However, K ₂ is the amplifier 13 and phase detector 15
Gains of a and 15b] Furthermore, if only the DC component is taken out by the low-frequency wave detector in 6, the output i _pd1 of the phase detectors 15a and 15b becomes the following equation.

i _pd1 =K ₃ I _A a ² /2 {K _V I _A A-I _M cos(α-
β)} (17) [However, K ₃ =K ₁ K ₂ K _V ] Furthermore, the output i _pd2 of the phase detector 15b based on a signal obtained by shifting the phase of the output of the low frequency oscillator 7 by 90° is given by the following equation.

i _pd2 =K ₃ I _A a ² /2 {K _V I _A B-I _M sin(α-β
)} (18) On the other hand, from the coordinates of the rotation center P of the vector 〓 _VM and the tip Q' of the vector 〓 _M ′ in Fig. 5, the following equation can be obtained regarding θ.

cosθ= _-IMcos (α-β)+ _AKVIA / _l (19
) sinθ= _-IM sin(α-β)+BK _{VI A} /l(20
) l=√{− _M (−)+ _{V A} } ² +{− _M (−)+ _{V A} } ² (21) From this, equations (17) and (18) can be written as follows.

i _pd1 = 1/2K ₃ I _A a ²・l cosθ (22) i _pd2 = 1/2K ₃ I _A a ²・l sinθ (23) Here, l is the vector 〓 Rotation center of _VM and vector 〓 Tip of _M ′, that is,
This is the distance between P and Q'. That is, the phase detector 15
The outputs i _pd1 and i _pd2 of a and 15b are vector modulator outputs = signal vector from the rotation center of _VM with equal amplitude and opposite phase to the input interference wave to main antenna 1 =
These are the real axis component and the imaginary axis component on the coordinate axes of FIG. 5 of the vector toward the tip of _M '.

Therefore, in the voltage integrators 6a, 6b, the phase detectors 15a, 15 are applied to the output voltages A, B up to that point.
When each output of voltage integrator 6a, 6b is converted into sign and integrated, each output of voltage integrator 6a, 6b becomes (A+K ₀ l cosθ), (B
+K ₀ l sin θ) [However, K ₀ =-(K ₃ I _A a ² )/2], and the vector modulator output changes to 〓 _VM ' next to 〓 _VM .

〓 _VM ′=-K _V I _A [(A+K ₀ l cosθ)+a cosω
t +j{(B=K ₀ l sinθ)+a sinωt}]e ^j(
〓 ^t+ 〓 ⁾ =I _A ″e ^j( 〓 ^t+ 〓 ⁺ 〓′ ⁾ (24) However, I _A ″=−K _V I _A √{(+ ₀ )+2 } ² +{(+ ₀ )+
} ² (25) φ′=tan ^-1 {(B+K ₀ l sinθ)+a sinωt/(A+K ₀ l cosθ)+a cosωt} (26) That is, 〓 _V ′ _M is P′(−K _V I _A (A+K ₀ l cosθ),
−K _V I _A (B+K ₀ l sinθ)) and the radius K
The tip of the vector rotates as if drawing a circle of _V aI _A , and the center of rotation approaches the vector 〓 _M ′. As a result of continuing this operation, the vector modulator output 〓 _VM
The tip of 〓 draws a circle with radius K _V aI _A centered on the tip of 〓 _M ′, that is, Q′ (A ₀ I _M , −B ₀ I _M ), and 〓 _VM and the input interference wave of main antenna 1 〓 _M and The resultant vector 〓 _E is the origin 0
It becomes a vector of length K _V aI _A rotating around .
Therefore, if a is chosen to be a suitably small value, the synthesizer 4
The output interference wave 〓 _E has a sufficiently small power and can suppress the interference wave.

The above has described the case where the vector modulator shown in FIG. 3 is used as the amplitude phase control circuit 3 in FIG. 2. The amplitude phase control circuit can also be realized by the configuration shown below.

FIG. 6 shows a configuration example of another amplitude phase control circuit 3, in which 17 is an input terminal, 22a, 22b are control signal input terminals, 25 is a signal branch circuit, 26a, 2
6b is a mixer, 27 is a 90° phase shifter, 29 is a signal combiner, and 23 is an output signal. The interference wave _A received by the auxiliary antenna is input to the input terminal 17 and branched into two systems by the signal branching circuit 25. One signal is input to mixer 26a, and the other signal is given a 90 degree phase shift by 90 degree phase shifter 27 and then input to mixer 26b. Mixer 26a at this time,
From equation (5), the input signals to 26b are each (I _0A /
2) It can be expressed as e ^j( 〓 ^t + 〓 ⁾ , j(I _0A /2) e ^j( 〓 ^t+ 〓 ⁾ . On the other hand, control signals (A+a cosωt) and (B+a sinωt) are also input to the mixers 26a and 26b from control signal input terminals 22a and 22b. Therefore, the output of the mixer 26a is K _M I _0A /2(A+a cosωt)e ^j( 〓 ^t+ 〓 ⁾ (27) (where K _M is the sensitivity of the mixer), and the output of the mixer 26 is
The output of b is j・K _M I _0A /2・(B+a sinωt) e ^j( 〓 ^t+ 〓 ⁾ (28). These mixer output signals are combined by a signal combiner 29 and output from an output terminal 23. Therefore, the signal _〓1 appearing at the output terminal 23 is as follows.

〓 ₁ =K _M I _0A /2 {(A+a cosωt) +j(B+a sinωt)}e ^j( 〓 ^t+ 〓 ⁾ (29) Here, since K _M and I _0A are constants, it has the same form as equation (6) Therefore, the same effect as a vector modulator can be obtained. However, in this case, in FIG. 2, the combiner 4 is a sum circuit when it is a vector modulator, but it needs to be a difference circuit.

Furthermore, Figure 7 shows a variable attenuator (or amplifier)
In the configuration example of the amplitude phase control circuit 3 when using a variable phase shifter, 17 is an input terminal, 22
a, 22b are control signal input terminals, 32 is a variable phase shifter, 33 is a variable attenuator (or amplifier), 35 is a signal conversion circuit, and 23 is an output terminal. The interference wave received by the auxiliary antenna is input through the input terminal 17, its phase is controlled by a variable phase shifter 32, and its amplitude is controlled by a variable attenuator (or amplifier) 33.
This control signal is obtained as follows. The control signal input from the control signal input terminal 22a (A+a cos
ωt) and the control signal input from 22b (B+a
sinωt) is calculated by the signal conversion circuit 35 as follows. i.e. variable attenuator (or amplifier)
The control signal S ₁ of the variable phase shifter 33 and the control signal S ₂ of the variable phase shifter 32 are as follows.

S ₁ =√(+) ² +(+
t) ² (30) S ₂ = tan ^-1 (B+a sinωt/A+a cosωt
) = φ (31) Furthermore, a variable attenuator (or amplifier) is used so that an amplitude proportional to this can be obtained by the control signal _S1 .
33, and the variable phase shifter 32 is controlled so as to obtain a phase shift proportional to _S2 . As a result, an output signal 〓 ₂ appears at the output terminal 23 .

〓 ₂ = I _0A = √ (+ ) ² + (+ ) ₂ e ^j( 〓 ^t+ 〓 ⁺ 〓 ⁾ (32) This output signal 〓 ₂ is also a signal proportional to 〓 _VM in equation (6), and is vector modulated. You can get the same effect as a vessel. However, in this case too, the synthesizer 4 in FIG. 2 is a difference circuit.

As explained above, according to the present invention, control information for the amplitude and phase of the auxiliary antenna reception signal is obtained only by changes in the power of the interference wave after compensation. Since they can be controlled simultaneously and directly controlled to the optimum value, there is an advantage that the response speed is fast.

[Brief explanation of the drawing]

Figure 1 is a configuration diagram of a conventional interference wave compensation device;
Fig. 3 is a block diagram of an embodiment of the device of the present invention, Fig. 3 is a block diagram of a vector modulator as an example of an amplitude phase control circuit used in the present invention, and Fig. 4 is a vector diagram of the attenuator output of the vector modulator. , FIG. 5 is a vector diagram of each signal of the interference wave compensator, FIG. 6 is another example of the amplitude phase control circuit used in the present invention, and is a configuration diagram when a mixer is used, and FIG. 7 is a diagram of the configuration of the present invention. FIG. 4 is a configuration diagram of still another example of the amplitude phase control circuit used in the present invention, in which a variable attenuator (or amplifier) and a variable phase shifter are used. 1...Main antenna, 2...Auxiliary antenna, 3...
... Amplitude phase control circuit, 4 ... Synthesizer, 5 ... Correlation detector, 6a, 6b ... Voltage integrator, 7 ... Low frequency oscillator, 8a, 8b ... Adder, 9 ... Frequency converter, 10... Bandpass wave generator, 11... Signal amplifier, 12... Envelope detector, 13... Amplifier, 14... 90° phase shifter, 15a, 15b... Phase phase detector, 16... Interference Wave compensation output, 17...Input terminal, 18...Signal branch circuit, 19a, 19
b, 19c, 19d...Fixed phase shifter, 20a, 2
0b, 20c, 20d...PIN attenuator, 21...
Signal synthesizer, 22... Control signal input terminal, 23...
...Output terminal, 25...Signal branch circuit, 26a, 2
6b...mixer, 27...90° phase shifter, 29...
Signal synthesizer, 32... variable phase shifter, 33... variable attenuator (or amplifier), 35... signal conversion circuit.

Claims (1)

[Claims] 1 A main antenna for communication, an auxiliary antenna for receiving interference waves, an amplitude phase control circuit that controls the amplitude and phase of the output of the auxiliary antenna using a control signal, a voltage integrator and a low voltage integrator for generating the control signal. A circuit that combines a frequency oscillator and an adder that adds the outputs of these, a synthesizer that synthesizes the output of the amplitude phase control circuit with a signal received by the main antenna, and extracts an interference wave frequency band from the output of the synthesizer. a band wave means, an envelope detector for detecting the power of the output of the band wave means, and a detection output obtained by synchronously detecting the output of the envelope detector and the output of the low frequency oscillator to the voltage integrator. and a synchronous detector, which extracts a combined output of a signal in which the amplitude and phase of the signal received by the auxiliary antenna are periodically slightly fluctuated by the control signal, and a signal received by the main antenna, and The difference between the phase of the interference wave power fluctuation and the output phase of the low frequency oscillator is obtained, the voltage due to this phase difference is integrated by the voltage integrator, and the output of the integrator and the output of the low frequency oscillator are An interference wave compensating device, characterized in that the control signal is created by adding the signals using an adder, and the interference wave is compensated on the output side of the combiner.