JPH05110481A - Interference wave elimination device - Google Patents

Abstract

PURPOSE:To obtain the interference wave elimination device in the diversity reception system processing reception signals from plural antennas installed at different points. CONSTITUTION:Fluctuation due to fading is eliminated from an input signal from antennas 101, 102 by AGC amplifiers 103, 104 respectively, the result is inputted to multipliers 105, 106, in which tap coefficients obtained by correlation devices 107, 108 are multiplied. The output of the multipliers is subject to in- phase synthesis and opposite phase synthesis at an in-phase synthesizer 109 and an opposite phase synthesizer 110. The outputs of amplifiers 111, 112 are inputted to a correlation device 113, in which the correlation is obtained. The correlation value and an automatic gain control voltage by the AGC amplifier 112 are inputted to an antenna controller 114 to control the antenna. Thus, a reception point is moved mechanically or electrically to make the relation between the phase of a desired wave with respect to the interference wave of one route and the phase of a desired wave by the interference wave of the other route is always made opposite to each other and the interference wave is eliminated without canceling the desired wave.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an interference wave canceller in a diversity receiving system for processing received signals from a plurality of antennas installed at different points.

[0002]

2. Description of the Related Art With the increase in communication capacity, the need for interference wave elimination is increasing in order to effectively utilize frequencies, which are finite resources. FIG. 6 shows a conventional example in the dual diversity system. An input signal from the antenna 601 is subjected to fading fluctuation removal by an automatic gain control (AGC) amplifier 603, input to a multiplier 605, and multiplied by a tap coefficient obtained by a correlator 607. The tap coefficient is a correlation value between the output signal of the AGC amplifier 603 and the reference signal after diversity combining. Similarly, the input signal from the antenna 602 is the AGC amplifier 6
The fading fluctuation is removed by 04, and the multiplier 606
The tap coefficient that is input to the input terminal and is multiplied by the tap coefficient obtained by the correlator 608 is a correlation value between the output signal of the AGC amplifier 604 and the reference signal after diversity combining.

In-phase combiner 609 performs in-phase combining of the output signal of multiplier 605 and the output signal of multiplier 606,
The AGC amplifier 611 amplifies it to a certain level and outputs it. On the other hand, the anti-phase combiner 610 performs anti-phase combining of the output signal of the multiplier 605 and the output signal of the multiplier 606, and A
The GC amplifier 612 amplifies it to a certain level and outputs it.

When there is no interference wave, the signal is output from the AGC amplifier 611, and when there is a large interference wave in which D / I, which is the level ratio between the desired wave and the interference wave, becomes negative, the desired wave signal is output. Are output from the AGC amplifier 612.

The interference wave removing operation will be described with reference to FIG. The desired wave of each route is S1 and S, respectively.
2 and the interference waves are J1 and J2. 7A and 7D show the output of the AGC amplifier 603 and the output of the AGC amplifier 604, respectively. Since the device is in-phase controlled by the interference wave, the interference waves J1 and J2 have the same amplitude and the same phase. The situation is shown in FIGS. 7 (b) and 7 (e). These are the outputs of multipliers 605 and 606, respectively. Further, the output of the in-phase combiner 609 is shown in FIG.
Shown in. In this way, the interference waves J1 and J2 are in-phase combined. The output of the anti-phase combiner 610 is shown in FIG. The interference wave is removed by anti-phase synthesis, and only the desired wave is obtained.

However, if the relationship between the phase / amplitude of the desired wave with respect to the interference wave of route 1 and the phase / amplitude of the desired wave with respect to the interference wave of route 2 is the same, the interference wave cannot be removed. 8 (a) and 8 (d) show the outputs of the AGC amplifiers 603 and 604, respectively. Outputs of the multipliers 605 and 606 are shown in FIGS. 8D and 8E, respectively. These are controlled in phase by the interference wave, and the interference wave J1
And J2 have the same amplitude and the same phase. Further, the output of the in-phase combiner 609 is shown in FIG. Interference waves J1 and J
2 is in-phase synthesized. The output of the anti-phase combiner 610 is shown in FIG. 8 (f), and both the interference wave and the desired wave are anti-phase combined and disappear.

[0007]

The phase of the desired wave with respect to the interference wave of one route and the desired wave with respect to the interference wave of the other route depend on the place where the interference wave is generated, the transmission place and the reception place of the non-line-of-sight communication, and the line condition. The relationship with the phase is determined. At this time, if the two sentences are the same, there is a problem in that the desired wave is also lost as the interference wave is removed.

[0008]

SUMMARY OF THE INVENTION An interference wave elimination device according to the present invention comprises a first automatic gain control amplifier for amplifying a signal from a first antenna, and an amplitude of an output signal of the first automatic gain control amplifier. A first multiplier for varying the phase, a second automatic gain control amplifier for amplifying the signal from the second antenna, and a first for varying the amplitude / phase of the output signal of the second automatic gain control amplifier A second multiplier, an in-phase combiner for in-phase combining the outputs of the first and second multipliers, a third automatic gain control amplifier for amplifying the output of the in-phase combiner to a constant level, and the third A first correlator for obtaining a correlation value between the output of the automatic gain control amplifier and the output of the first automatic gain control amplifier, and outputting the correlation value to the first multiplier; and the first and second multipliers. And a reverse-phase combiner for reverse-phase combining the outputs of the A fourth automatic gain control amplifier that amplifies the output of the amplifier to a constant level, and a correlation value between the output of the fourth automatic gain control amplifier and the output of the second automatic gain control amplifier, and the second multiplication A second correlator for outputting to the antenna and an antenna controller for controlling the position of the antenna by one of the automatic gain control voltages in the third and fourth automatic gain control amplifiers.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a more detailed description will be given with reference to the drawings showing an embodiment of the present invention.

Referring to FIG. 1, in the first embodiment in which the present invention is applied to the dual diversity reception system, the input signal from the antenna 101 is subjected to fading fluctuation removal by the AGC amplifier 103, and then fed to the multiplier 105. It is input and multiplied by the tap coefficient obtained by the correlator 107. The tap coefficient is the output signal of the AGC amplifier 103,
It is a correlation value with the reference signal after diversity combining. Similarly, the input signal from the antenna 102 is the AGC amplifier 1
Fluctuation due to fading is removed by 04, input to the multiplier 106, and multiplied by the tap coefficient obtained by the correlator 108. The tap coefficient is a correlation value between the output signal of the AGC amplifier 104 and the reference signal after diversity combining. In-phase combiner 109 performs in-phase combining of the output of multiplier 105 and the output of multiplier 106, and AGC
The amplifier 111 amplifies it to a constant level and outputs it. On the other hand, the output of the multiplier 105 and the output of the multiplier 106 are anti-phase combined by the anti-phase combiner 110, and the AGC amplifier 11
At 2, it is amplified to a certain level and output.

The output of the in-phase combined signal system AGC amplifier 111 and the output of the anti-phase signal system AGC amplifier 112 are input to the correlator 113, and the correlation value is obtained. The obtained correlation value is input to the antenna controller 114, and the automatic gain control voltage corresponding to the input level of the AGC amplifier 112 is also input to the antenna controller 114 to control the antenna. This is because the position of the antenna is controlled electrically or mechanically so that there is no correlation between the in-phase combined signal and the anti-phase combined signal, so that the phase of the interference wave with respect to the desired wave of one route and the desired of the other route. The relation between the phase of the interference wave and the phase of the interference wave is always weak phase, and the level ratio D / I of the desired wave and the interference wave is set.
When there is a small interference in which is positive, the desired wave is output to the in-phase combiner port, the interference wave is output to the anti-phase combiner port, and when there is a large interference in which D / I becomes negative,
The interference wave is output to the in-phase combiner port, and the desired wave is output to the anti-phase combiner port.

Further, when the correlation value of the correlator 113 disappears, the phase of the desired wave and the interference wave of one route and the phase of the desired wave and the interference wave of the other route become in phase, and the in-phase synthesis port This includes the case where both the desired wave and the interference wave are output and the level of the anti-phase combining port disappears. this is,
Since it is desirable, the automatic gain control voltage corresponding to the level of the anti-phase combining port is detected and input to the antenna controller 114 to avoid this state.

The interference removing operation will be described with reference to FIG. This figure shows the positional relationship, where T is the transmission location,
J is an interference oscillation place, R1 and R2 are reception places, and T to R
The distances from 1, T to R2, J to R1, and J to R2 are r1, r2, j1, and j2, respectively. By the control according to the present embodiment, the phases of the desired wave and the interference wave at R1,
For example, R1 is moved in the R2 direction or the opposite direction so that the relationship between the phase of the desired wave and the phase of the interference wave in R2 is always in the opposite phase. This operation is shown in FIG.
As a method of moving the position of the antenna, there are a method of using a phased array antenna and electrically moving the center of the beam, and a method of mechanically moving the beam.

Referring to FIG. 2, in the second embodiment in which the present invention is applied to the dual diversity reception system, the input signal from the antenna 201 is subjected to fading fluctuation removal by the AGC amplifier 203, and is then sent to the multiplier 205. It is input and multiplied by the tap coefficient calculated by the correlator 207. The tap coefficient is the output signal of the AGC amplifier 203,
It is a correlation value with the reference signal after diversity combining. Similarly, the input signal from the antenna 202 is the AGC amplifier 2
Fluctuation due to fading is removed by 04, input to the multiplier 206, and multiplied by the tap coefficient obtained by the correlator 208. The tap coefficient is a correlation value between the output signal of the AGC amplifier 204 and the reference signal after diversity combining. The in-phase combiner 209 performs in-phase combining of the output of the multiplier 205 and the output of the multiplier 206.
The amplifier 211 amplifies it to a constant level and outputs it. On the other hand, the output of the multiplier 205 and the output of the multiplier 206 are subjected to anti-phase synthesis by the anti-phase synthesizer 210, and the AGC amplifier 21
At 2, it is amplified to a certain level and output.

The automatic gain control voltage value corresponding to the input level of the in-phase combined signal system AGC amplifier 211 is input to the antenna controller 213 to control the antenna. This is because the position of the antenna is controlled electrically or mechanically so as to find the minimum value of the in-phase combined signal because the desired wave does not include the interference wave or the interference wave does not include the desired wave. When the relationship between the phase of the interference wave with respect to the desired wave and the phase of the interference wave with respect to the desired wave of the other route is always opposite, and there is small interference in which the level ratio D / I of the desired wave and the interference wave is positive, , If the desired wave is output to the in-phase combining port, the interference wave is output to the anti-phase combining port, and there is a large interference in which the D / I becomes negative, the interference wave is output to the in-phase combining port and the desired wave is output. It is output to the reverse phase synthesis port. The interference removing operation is the same as in the first embodiment.

Referring to FIG. 3, in the third embodiment in which the present invention is applied to the dual diversity reception system, the input signal from the antenna 301 is subjected to fading fluctuation removal by the AGC amplifier 303, and is then sent to the multiplier 305. It is input and multiplied by the tap coefficient calculated by the correlator 307. The tap coefficient is the output signal of the AGC amplifier 303,
It is a correlation value with the reference signal after diversity combining. Similarly, the input signal from the antenna 302 is the AGC amplifier 3
Fluctuation due to fading is removed by 04, input to the multiplier 306, and multiplied by the tap coefficient obtained by the correlator 308. The tap coefficient is a correlation value between the output signal of the AGC amplifier 304 and the reference signal after diversity combining. The in-phase combiner 309 performs in-phase combining of the output of the multiplier 305 and the output of the multiplier 306, and the AGC
The amplifier 311 amplifies it to a constant level and outputs it. On the other hand, the output of the multiplier 305 and the output of the multiplier 306 are anti-phase combined by the anti-phase combiner 310, and the AGC amplifier 31
At 2, it is amplified to a certain level and output.

An automatic gain control voltage value corresponding to the input level of the anti-phase composite signal system AGC amplifier 312 is input to the antenna controller 313 to control the antenna. This is because the position of the antenna is controlled electrically or mechanically so as to obtain the maximum value of the in-phase combined signal because the desired wave does not include the interference wave or the interference wave does not include the desired wave. When the relationship between the phase of the interference wave with respect to the desired wave and the phase of the interference wave with respect to the desired wave of the other route is always opposite, and there is small interference in which the level ratio D / I of the desired wave and the interference wave is positive, , If the desired wave is output to the in-phase combining port, the interference wave is output to the anti-phase combining port, and there is a large interference in which the D / I becomes negative, the interference wave is output to the in-phase combining port and the desired wave is output. It is output to the reverse phase synthesis port. The interference removing operation is the same as in the first embodiment.

[0018]

As described above, according to the present invention,
Conventionally, all the locations of interference, transmission, and reception were fixed, but by moving the reception mechanically or electrically, the phase of the desired wave with respect to the interference wave of one route The relationship between the phase of the desired wave and the phase of the desired wave with respect to the interference wave of the other route can always be made opposite in phase, and the interference wave can be removed without losing the desired wave.

[Brief description of drawings]

FIG. 1 is a block diagram of a first embodiment of the present invention.

FIG. 2 is a block diagram of a second embodiment of the present invention.

FIG. 3 is a block diagram of a third embodiment of the present invention.

FIG. 4 is a diagram for explaining the operation of the embodiment shown in FIGS.

FIG. 5 is a diagram for explaining the operation of the embodiment shown in FIGS.

FIG. 6 is a block diagram of an interference wave removing device according to a conventional example.

FIG. 7 is a diagram for explaining the operation of the conventional example shown in FIG.

8 is a diagram for explaining the operation of the conventional example shown in FIG.

[Explanation of symbols]

101, 102, 201, 202, 301, 302, 6
01,602 antennas 103,104,203,204,303,304,6
03,604 AGC amplifier 105,106,205,206,305,306,6
05,606 Multipliers 107, 108, 207, 208, 307, 308, 6
07,608 Correlator 109,209,309,609 In-phase combiner 110,210,310,610 Anti-phase combiner 111,112,211,212,311,312,6
11,612 AGC amplifier 113 Correlator 114,213,313 Antenna controller

Claims (3)

[Claims] 1. A first automatic gain control amplifier for amplifying a signal from a first antenna; a first multiplier for varying the amplitude and phase of an output signal of the first automatic gain control amplifier; A second automatic gain control amplifier for amplifying a signal from the second antenna; a second multiplier for varying the amplitude and phase of the output signal of the second automatic gain control amplifier; and the first and second An in-phase combiner for in-phase combining the outputs of the multipliers, a third automatic gain control amplifier for amplifying the output of the in-phase combiner to a constant level, an output of the third automatic gain control amplifier and the first automatic Obtaining a correlation value with the output of the gain control amplifier, a first correlator for outputting to the first multiplier, an anti-phase combiner for performing anti-phase combining the outputs of the first and second multipliers, A fourth automatic amplifier that amplifies the output of the anti-phase combiner to a constant level. A gain control amplifier, a second correlator for obtaining a correlation value between the output of the fourth automatic gain control amplifier and the output of the second automatic gain control amplifier, and outputting the correlation value to the second multiplier, An interference wave elimination device, comprising: an antenna controller that controls the position of the antenna by one of the automatic gain control voltages in the third and fourth automatic gain control amplifiers. 2. The antenna controller has a third correlator for determining a correlation value of outputs of the second and fourth automatic gain control amplifiers, and the output of the third correlator and the fourth correlator are provided. 2. The interference wave removing apparatus according to claim 1, wherein the position of the antenna is controlled by the automatic gain control voltage in the automatic gain control amplifier. 3. The antenna controller ensures that the relationship between the phase of the desired wave with respect to the interference wave of one route and the phase of the desired wave with respect to the interference wave of the other route is always in opposite phase.
The interference wave removing device according to claim 1, which controls the antenna.