JP2001044968A - Device and method for eliminating signal and recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a signal eliminating device and a signal eliminating method for eliminating an interference waves whose frequency is unspecified without deteriorating communication quality. SOLUTION: CDMA signals divided by distributors 1-1 to 1-3 are supplied to mixers 2-1 to 2-3. Meanwhile, oscillators 6-1 to 6-3 supply alternating current signals of a frequency shown by a control signal issued by a controlling part 9 to the mixers 2-1 to 2-3, and three interference waves on which the CDMA signals are superimposed are consequently converted into the same frequency, made to pass through BPFs 3-1 to 3-3, further subjected to phase shift by phase adjusting devices 4-1 to 4-3, next returned to the original frequency by mixers 5-1 to 5-3 to which the alternating current signals are supplied from the oscillators 6-1 to 6-3 and supplied to adders 7-1 and 7-3. The interference waves supplied from mixers 5-1 to 5-3 to the adders 7-1 and 7-3 are eliminated by an addition because they are subjected to phase shift to be a negative phase to the original interference waves.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a signal elimination apparatus and a signal elimination method, and more particularly to a signal elimination apparatus and a signal elimination method for eliminating a signal occupying a specific frequency band.

[0002]

2. Description of the Related Art In signal transmission, it is generally necessary to eliminate or reduce the influence of interfering waves mixed in the occupied frequency bandwidth of a signal to be transmitted. As a communication method for reducing the influence of the interference wave, for example, there is spread spectrum communication. In spread spectrum communication, when a narrow band interfering wave whose occupied frequency bandwidth is narrower than that band is mixed in the band to be received, the interfering wave is also spread in the process of despreading the received signal. . As a result, the power due to the interference wave included in the signal obtained by demodulation is reduced.

[0003] However, if the power of the interfering wave mixed into a device that performs spread spectrum communication increases to such an extent that stable communication quality cannot be maintained even with the effect of reducing the interfering wave due to spread spectrum communication, the communication becomes stable. Not done. Such a problem occurs, for example, when a device that receives a spread-spectrum signal is used in the same frequency band with another communication device that is a source of a narrow-band interference wave.

In order to solve the above-mentioned problem, it is effective to remove narrow-band interference waves scattered in the band of the spread spectrum signal before despreading. As a method of removing a narrow-band interference wave existing in the band of a signal to be received, a method disclosed in Japanese Unexamined Patent Application Publication No. 5-327658 is known.
And Japanese Patent Application Laid-Open No. 6-31501.
There is a technique disclosed in Japanese Patent Application Publication No. 8 (JP-A-8).

According to the technique disclosed in Japanese Patent Application Laid-Open No. Hei 5-327658, a narrow band interference wave is extracted from a signal to be received by a BPF having a fixed pass band, and the extracted interference wave is received. The interference wave is removed by subtraction from the target signal.

In the technique disclosed in Japanese Patent Application Laid-Open No. Hei 6-315018, signals belonging to respective sections obtained by dividing a band of a spread spectrum signal into a plurality of bands are filtered by separate BPFs from each other. By detecting a component that has passed through the BPF, a section in which a narrow-band interference wave exists is specified. And by the band elimination circuit,
The signal belonging to the section where the interference wave is detected is removed.

[0007]

However, Japanese Patent Application Laid-Open No. 5-3
In the technique of 27658, since the pass band of the BPF is fixed, only the interference wave occupying a predetermined specific band can be removed. That is, this technique can be effectively used only when the band occupied by the narrow-band interference wave to be removed is specified in advance. Therefore, this technique cannot be used when the frequency at which the narrow-band interfering wave is mixed is unknown or indeterminate within the band of the spread spectrum signal to be received.

On the other hand, according to the technique disclosed in Japanese Patent Application Laid-Open No. 6-315018, even when a narrow-band interference wave is generated at an unspecified frequency within the band of a spectrum-spread signal,
This can be eliminated. However, with this technology,
Since the signal belonging to the same section as the interfering wave is also removed, the wider the pass band of the BPF, the lower the communication quality.
On the other hand, as the pass band of the BPF becomes narrower, the number of BPFs and detection circuits required for filtering the entire signal contained in the band of the spread spectrum signal increases, and the configuration of the device becomes more complicated and larger.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a signal elimination apparatus and a signal elimination method for eliminating an interference wave having an unspecified frequency without deteriorating communication quality. .

[0010]

In order to achieve the above object, a signal elimination apparatus according to a first aspect of the present invention provides a signal elimination device for extracting, from a signal supplied thereto, a component whose frequency belongs to a predetermined filter pass band. A band-pass filter to pass,
Applying frequency conversion to the signal to be processed, so that the frequency of the component to be removed included in the signal to be processed belongs to the filter pass band, and the signal to be processed subjected to frequency conversion to the band-pass filter. A first frequency shifter to be supplied, and a frequency conversion of the component passed through the band-pass filter, and the frequency of the component is a signal to be processed before being subjected to the frequency conversion by the first frequency shifter. A second frequency shifter that makes the frequency substantially equal to the frequency of a component to be removed included in the signal to be removed, and a target to be removed included in a signal to be processed before being subjected to frequency conversion by the first frequency shifter. Based on the component and the component subjected to frequency conversion by the second frequency shifter,
A component remover for removing the component to be removed from a signal to be processed that has not been subjected to frequency conversion by the first frequency shifter.

According to such a signal removing apparatus, a component to be removed of an arbitrary frequency is extracted in a state where it is frequency-converted into a signal having a frequency belonging to a predetermined filter pass band, and based on the extracted signal, Thus, the component to be removed is removed from the signal to be processed. Therefore, the removal target component having an unspecified frequency is also removed without deteriorating the communication quality.

[0012] The component remover may be, for example, an instantaneous value of a signal to be processed before being subjected to frequency conversion by the first frequency shifter and subjected to frequency conversion by the second frequency shifter. A signal having an instantaneous value corresponding to the sum of the instantaneous value of the component and the instantaneous value is generated by removing the component to be removed from the signal to be processed before being subjected to frequency conversion by the first frequency shifter. By providing an adder for removing, a component to be removed is removed. In this case, the signal removal device includes the phase of the component subjected to the frequency conversion by the second frequency shifter in the signal to be processed before the frequency conversion by the first frequency shifter. It is sufficient to provide a phase adjuster that adjusts the result of the frequency conversion by the second frequency shifter so that the phase is substantially opposite to the phase of the component to be removed.

[0013] The component remover may be, for example, an instantaneous value of a signal to be processed before being subjected to frequency conversion by the first frequency shifter and subjected to frequency conversion by the second frequency shifter. A signal having an instantaneous value corresponding to the difference between the component and the instantaneous value is generated as a signal obtained by removing the component to be removed from a signal to be processed before being subjected to frequency conversion by the first frequency shifter. By providing a subtractor for removing, a component to be removed is removed. In this case, the signal removal device includes the phase of the component subjected to the frequency conversion by the second frequency shifter in the signal to be processed before the frequency conversion by the first frequency shifter. It is sufficient to provide a phase adjuster that adjusts the result of the frequency conversion by the second frequency shifter so that the phase of the component to be removed is substantially in phase with the phase of the component to be removed.

This signal elimination device identifies the frequency of the component to be eliminated and generates a local oscillation signal having a frequency corresponding to the sum or difference between the identified frequency and the frequency belonging to the predetermined filter pass band. If a component to be removed is provided, the component to be removed is detected by itself and its frequency is specified. Then, the first frequency shifter is, for example, a component whose frequency belongs to the filter pass band in the result of heterodyne mixing the signal to be processed and the local oscillation signal, A first mixer for supplying the signal as a signal to the band-pass filter, wherein the second frequency shifter includes, for example,
The frequency of the component to be removed included in the signal to be processed before being subjected to frequency conversion by the first frequency shifter out of the result of heterodyne mixing the component having passed through the band-pass filter and the local oscillation signal. The frequency conversion is performed by providing a second mixer that generates a component having substantially the same frequency as a result of performing frequency conversion on the component that has passed through the band-pass filter.

[0015] The removal target component detection means, for example, outputs the scanning local oscillation signal for sweeping a band corresponding to a sum or difference between a band including the signal to be processed and a frequency belonging to the filter pass band to the first. Scanning means for supplying to the frequency shifter, and frequency specifying means for specifying the frequency of the component to be removed based on the intensity of the component having passed through the band-pass filter, whereby the frequency of the component to be removed is provided. To identify.

A signal removing method according to a second aspect of the present invention performs frequency conversion on a signal to be processed, and a frequency of a component to be removed included in the signal to be processed belongs to a predetermined filter pass band. A first frequency shift step, a band filter step of extracting a component whose frequency belongs to a predetermined filter pass band from a signal subjected to frequency conversion in the first frequency shift step, Performing frequency conversion on the component extracted in the step, and the frequency of the component is substantially equal to the frequency of the component to be removed included in the signal to be processed before being subjected to the frequency conversion in the first frequency shift step. A second frequency shifting step to make them equal,
Based on the component to be removed included in the signal to be processed before being subjected to frequency conversion in the frequency shift step and the component subjected to frequency conversion in the second frequency shift step. A component removing step of removing the component to be removed from a signal to be processed which has not been subjected to frequency conversion in the shifting step.

According to such a signal removing method, a component to be removed having an arbitrary frequency is extracted in a state where it is frequency-converted into a signal having a frequency belonging to a predetermined filter pass band, and based on the extracted signal, Thus, the component to be removed is removed from the signal to be processed. Therefore, the removal target component having an unspecified frequency is also removed without deteriorating the communication quality.

Further, a computer-readable recording medium according to a third aspect of the present invention includes:
A band-pass filter that passes a component whose frequency belongs to a predetermined filter pass band in a signal supplied to itself, and performs frequency conversion on a signal to be processed, and a frequency of a component to be removed included in the signal to be processed. A first frequency shifter that supplies the signal to be processed, which has been subjected to frequency conversion, to the band-pass filter so that the signal belongs to the filter pass band, and performs frequency conversion on a component that has passed through the band-pass filter. A second frequency shifter that makes the frequency of the component substantially equal to the frequency of the component to be removed included in the signal to be processed before being subjected to frequency conversion by the first frequency shifter. And the first
The first frequency based on a component to be removed included in a signal to be processed before being subjected to frequency conversion by the frequency shifter and a component subjected to frequency conversion by the second frequency shifter. It is characterized by recording a program for functioning as a component remover for removing the component to be removed from a signal to be processed which has not been subjected to frequency conversion by the shifter.

A computer that executes a program recorded on such a recording medium extracts a component to be removed having an arbitrary frequency in a state where the component is frequency-converted into a signal having a frequency belonging to a predetermined filter pass band. Based on the extracted signal, a component to be removed is removed from the signal to be processed. Therefore, the removal target component having an unspecified frequency is also
It is removed without deteriorating the communication quality.

[0020]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a signal removing apparatus according to an embodiment of the present invention.
e Access) An interference wave removing device for removing an interference wave included in a signal will be described as an example.

FIG. 1 shows an example of the configuration of an interference wave removing apparatus according to an embodiment of the present invention. As shown in the figure, this interfering wave removing apparatus includes a number n (where n is the number of interfering waves to be removed) of distributors 1-1 to 1-n and a number n of mixers 2-1 to 2-1. 2-n and number n of mixers 5-1
5-n and n number of BPFs (Band Pass Filters) 3-1
... 3-n, n number of phase adjusters 4-1 to 4-n, n number of oscillators 6-1 to 6-n, and n number of adders 7-1
7-n, the number n of detection units 8-1 to 8-n, and the control unit 9.

The distributors 1-1 to 1-n have substantially the same configuration as each other, and each has an input terminal and first and second output terminals. Each of the distributors 1-1 to 1-n outputs a signal supplied to its own input terminal from its own first and second output terminals.

The first output terminal of the distributor 1-1 is connected to the mixer 2-
1 is connected to a first input terminal, which will be described later, and a distributor 1-
2 is connected to the first input of the mixer 2-2, and so on, the first output of the distributor 1-k, where k is a natural number less than or equal to n. Is the first of the mixer 2-k
Is connected to the input terminal of

The input terminal of the distributor 1-1 forms the input terminal of the interference wave removing device. The second output terminal of the distributor 1-1 is connected to the input terminal of the distributor 1-2. Similarly, the second output terminal of the distributor 1-j (j is a natural number smaller than n) is connected to the second output terminal of the distributor 1-1.
Is connected to the input terminal of the distributor 1- (j + 1). A second output terminal of the distributor 1-n is connected to a later-described first input terminal of the adder 7-1.

The mixers 2-1 to 2-n have substantially the same configuration as each other, and have first and second input terminals and output terminals, respectively. The mixers 2-1 to 2-n perform heterodyne mixing of the respective signals supplied to the first and second input terminals thereof, and a difference component between the mixed signals (that is, the first and second components). Having a frequency substantially equal to the difference between the frequencies of the signals supplied to the respective input terminals (i.e., the signals supplied to the respective input terminals) are output from the respective output terminals as a result of the frequency conversion.

The first input of the mixer 2-k is connected to the first output of the distributor 1-k as described above. A second input terminal of the mixer 2-1 is connected to an output terminal described later of the oscillator 6-1. A second input terminal of the mixer 2-2 is connected to an output terminal of the oscillator 6-2. Similarly, the second input terminal of the mixer 2-k is connected to the output terminal of the oscillator 6-k. The output terminal of the mixer 2-k is a BPF3-k
Is connected to an input terminal described later.

Each of the BPFs 3-1 to 3-n has an input terminal and an output terminal. The BPFs 3-1 to 3-n pass through the frequency components belonging to a predetermined pass band of the signals supplied to the respective input terminals, output the signals from the respective output terminals, and substantially block other frequency components. I do. BPF3-1-3
The -n passband is selected, for example, so that the BPFs 3-1 to 3-n pass substantially the same frequency components.

As described above, the input terminal of the BPF 3-k is connected to the output terminal of the mixer 2-k, and the output terminal of the BPF 3-k is connected to an input terminal of the phase adjuster 4-k, which will be described later. Have been.

Each of the phase adjusters 4-1 to 4-n is composed of an all-pass filter or the like, and has an input terminal and an output terminal. The phase adjusters 4-1 to 4-n shift the phases of the signals supplied to the respective input terminals by an amount corresponding to the phase shift amount unique to the respective terminals, and output the signals obtained by the phase shift to the respective output terminals. Output from the end. This phase shift amount unique to each of the phase adjusters 4-1 to 4-n is set in advance, for example, so as to meet a condition described later.

As described above, the input terminal of the phase adjuster 4-k is connected to the output terminal of the BPF 3-k, and the output terminal of the phase adjuster 4-k is connected to a later-described terminal of the mixer 5-k. 1 input terminal.

The mixers 5-1 to 5-n have substantially the same configuration as each other, and have first and second input terminals and output terminals, respectively. The mixers 5-1 to 5-n perform heterodyne mixing of the respective signals supplied to the respective first and second input terminals, and a sum component of the mixed respective signals (that is, the first and second components). ) Having a frequency substantially equal to the sum of the frequencies of the signals supplied to the respective input terminals (i.e., the signals supplied to the respective input terminals).

The first input terminal of the mixer 5-k is connected to the output terminal of the phase adjuster 4-k as described above. The second input of the mixer 5-k is connected to the output of the oscillator 6-k. The output terminal of the mixer 5-k is connected to an adder 7-k.
Is connected to a second input terminal described later.

The oscillators 6-1 to 6-n have substantially the same configuration as each other, and each has a control input terminal and an output terminal. When a control signal is supplied to each of the control input terminals, each of the oscillators 6-1 to 6-n outputs an AC signal (for example, a sine wave) having a frequency indicated by the control signal from its own output terminal. The control input terminal of the oscillator 6-k is connected to the control unit 9. As described above, the output terminal of the oscillator 6-k is connected to the second input terminal of the mixer 2-k and the second input terminal of the mixer 5-k.

The adders 7-1 to 7-n have substantially the same configuration as each other, and have first and second input terminals and an output terminal, respectively. Each of the adders 7-1 to 7-n outputs a signal having an instantaneous value corresponding to the sum of the instantaneous values of the signals supplied to its own first and second input terminals from its own output terminal.

The second input terminal of the adder 7-k is connected to the mixer 5
-K output terminal. The first input terminal of the adder 7-1 is connected to the output terminal of the distributor 1-n as described above. The output terminal of the adder 7-1 is the first terminal of the adder 7-2.
Of the adder 7-j.
The first output terminal of (j is a natural number smaller than n) is an adder 7
-(J + 1) is connected to the first input terminal. The output terminal of the adder 7-n forms the output terminal of the interference wave removing device.

Each of the detectors 8-1 to 8-n is constituted by a detector or the like, and has a detection terminal and an output terminal. The detection units 8-1 to 8-n detect the intensity of the AC voltage applied to their respective detection terminals (for example, the effective value or the peak value of the AC voltage) and output a signal representing the detected value. , Output from their own output terminals. The detection end of the detection unit 8-k is a BPF3-
k, and the output terminals of the detection units 8-1 to 8-n are connected to the control unit 9.

The control unit 9 includes, for example, a CPU (Central Pr
Ocessing Unit). Control unit 9
Obtains signals output from the output terminals of the detection units 8-1 to 8-n, monitors the intensity of the AC voltage detected by the detection units 8-1 to 8-n, and outputs the signals to the oscillators 6-1 to 8-n. By scanning the frequency of the AC signal to be generated in each of the 6-n units, a maximum of n interference waves included in the signal acquired by the interference wave elimination device are detected. And BPF3-1-3-
The frequency of the AC signal generated in each of the oscillators 6-1 to 6-n is determined so that n passes different interference waves.

As a specific method of determining the frequency, for example, the control unit 9 first obtains a signal output from the output terminal of the detection unit 8-1, and obtains the AC voltage detected by the detection unit 8-1. While repeatedly determining whether or not the intensity of the signal has substantially reached a maximum, a control signal for continuously increasing the frequency starting from the lower limit of the band of the desired wave is input to the control input terminal of the oscillator 6-1. Supply.

When it is determined that the intensity of the AC voltage detected by the detection unit 8-1 has substantially reached the maximum due to the interfering wave passing through the BPF3-1, the oscillator 6-1 is determined at the time of the determination. Is supplied to the oscillator 6-1 after that point in time, the control signal having substantially the same value as the control signal supplied to the oscillator 6-1. That is, the oscillator 6
The frequency of the AC signal to be generated at −1 is determined (in other words, the frequency before the frequency conversion of the interference wave passing through the BPF 3-1 is also specified).

Subsequently, the control section 9 repeatedly determines whether or not the value detected by the detection section 8-2 has substantially reached a maximum, and outputs the signal to the control input terminal of the oscillator 6-2. A control signal is supplied to continuously increase the frequency starting from the frequency of the AC signal generated by 1. When it is determined that the value detected by the detection unit 8-2 has substantially reached the maximum due to the interfering wave passing through the BPF 3-2, the oscillator 6
-2 is determined to be the frequency of the AC signal generated at the time when the discrimination is performed.
The frequency before the frequency conversion of the interfering wave passing through −2 is specified).

If (n> 2), the controller 9
Hereinafter, the procedure is substantially the same as the procedure for fixing the frequency of the AC signal generated by the oscillator 6-2, and
For −n, the frequency of the AC signal to be generated by the oscillator is determined sequentially (and the frequency of the interfering wave passing through the BPF 3-h before the frequency conversion is specified). However, while the control unit 9 repeatedly determines whether the value detected by the detection unit 8-h (where h is a natural number of 3 or more and n or less) substantially reaches a maximum, the oscillator 6-h At the control input end of
It is assumed that a control signal is supplied to continuously increase the frequency starting from the frequency of the AC signal generated by the oscillator 6- (h-1).

(Operation) Next, when the interference wave to be removed is 3
The operation of the interference wave canceling apparatus for removing these interference waves superimposed on the desired wave will be described by taking, as an example, the case where the number is n (that is, the case where n = 3).

In this interference wave removing apparatus, three interference waves (hereinafter referred to as "first interference wave", "second interference wave", and "
Is supplied, the first to third interfering waves and the desired wave are distributed between the first input terminal and the output terminal of the distributor 1-1 and the distributor. 1-2, and sequentially passes between a first input terminal and an output terminal of the distributor 1-3, and further, a first input terminal and an output terminal of the adder 7-1. Between the first input terminal and the output terminal of the adder 7-2 and between the first input terminal and the output terminal of the adder 7-3.
The signal is output to the output terminal of the interference wave removing device.

On the other hand, the desired wave and the first to third interfering waves are also supplied to the first input terminals of the mixers 2-1 to 2-3. As a result, from the output end of the mixer 2-1, the first,
The difference component between the second and third interfering waves and the AC signal generated by the oscillator 6-1 is output to the input terminal of the BPF 3-1. From the output terminal of the mixer 2-2, the difference component between the first, second and third interference waves and the AC signal generated by the oscillator 6-2 is output to the input terminal of the BPF 3-2. Is done. From the output end of the mixer 2-3, the first, second, and third
The component of the difference between the disturbing wave and the AC signal generated by the oscillator 6-3 is output to the input terminal of the BPF 3-3. And
Each of the BPFs 3-1 to 3-3 outputs a component having a frequency of fc from among its components supplied to its own input terminal from its own output terminal.

Then, the detection units 8-1 to 8-3 perform the BPF
The intensity of the component output from the output terminals of 3-1 to 3-3 is detected, and a signal indicating the detected value is supplied to the control unit 9.
As described above, the control unit 9 monitors the oscillators 6-1 to 6-3 while monitoring the intensities of the components detected by the detection units 8-1 to 8-3.
Are detected by detecting the frequency of the AC signal to be generated in each of the three interference waves. Then, the frequency of the AC signal generated in each of the oscillators 6-1 to 6-3 is determined by the above-described procedure so that the BPFs 3-1 to 3-3 pass different interference waves.

Assuming that the frequency of the first interference wave is fx, the frequency of the second interference wave is fy, and the frequency of the third interference wave is fz (where fx <fy <fz), As a result, the control unit 9 supplies a control signal indicating the frequency (fx-fc) to the control input terminal of the oscillator 6-1 and outputs the frequency (fy-fc) to the control input terminal of the oscillator 6-2. And a control signal indicating the frequency (fz-fc) is determined to be supplied to the control input terminal of the oscillator 6-3. In this case, the mixer 2-1 is output from the output terminal of the oscillator 6-1.
Is supplied with an AC signal having a frequency (fx-fc), and an AC signal having a frequency (fy-fc) is supplied from the output terminal of the oscillator 6-2 to the second input terminal of the mixer 2-2. A signal is supplied, and an AC signal having a frequency (fz-fc) is supplied from an output terminal of the oscillator 6-3 to a second input terminal of the mixer 2-3.

As a result, from the output end of the mixer 2-1,
As components of the difference between the first, second, and third interfering waves and the AC signal generated by the oscillator 6-1, the frequencies are fc,
A signal including three components of (fy−fx + fc) and (fx−fx + fc) is output. That is, the first to third interfering waves whose frequencies are fx, fy and fz in order are fc, (fy-fx + fc) and (f
z-fx + fc). The BPF 3-1 outputs a component having a frequency of fc (that is, the first interfering wave and the oscillator 6) out of the three components.
(-1) is passed to the input terminal of the phase adjuster 4-1.

From the output terminal of the mixer 2-2, as a component of a difference between the first, second, and third interfering waves and the AC signal generated by the oscillator 6-2, the frequency sequentially becomes ( fx-
fy + fc), fc and (fz−fy + fc) 3
A signal including the number of components is output. That is, the first to third interfering waves have the frequency of (fx−fy + fc), f
c and (fz-fy + fc). The BPF 3-2 passes a component having a frequency of fc (that is, a difference component between the second interference wave and the AC signal generated by the oscillator 6-2) among these three components,
It is supplied to the input terminal of the phase adjuster 4-2.

From the output terminal of the mixer 2-3, as the difference component between the first, second, and third interfering waves and the AC signal generated by the oscillator 6-3, the frequency sequentially becomes ( fx-
fz + fc), (fy−fz + fc) and 3 which is fc
A signal including the number of components is output. That is, the first to third interfering waves have the frequency of (fx−fz + fc) in order,
The frequency conversion is performed so that (fy−fz + fc) and fc. The BPF 3-3 passes a component having a frequency of fc (that is, a difference component between the third interference wave and the AC signal generated by the oscillator 6-3) among the three components, and 4-3.

The phase adjuster 4-1 shifts the phase of the signal supplied from the BPF 3-1 to its own input terminal, and outputs the signal obtained by the phase shift from its own output terminal to the mixer 5-1. 1 to the input terminal. However, the phase adjuster 4-1 supplies a signal supplied from the output terminal of the mixer 5-1 to the second input terminal of the adder 7-1 and a signal supplied to the first input terminal of the adder 7-1. The phase of the signal supplied to itself is shifted so that the component having a frequency of fx in the signal to be output has substantially the opposite phase.

Similarly to the phase adjuster 4-1, the phase adjuster 4-2 shifts the phase of the signal supplied from the BPF 3-2 to the first input terminal of the mixer 5-2. Output to Similarly to the phase adjuster 4-1, the phase adjuster 4-3 shifts the phase of the signal supplied thereto from the BPF 3-3 and outputs the shifted signal to the first input terminal of the mixer 5-3. I do. However, the phase adjuster 4-2 supplies the signal supplied from the output terminal of the mixer 5-2 to the second input terminal of the adder 7-2 and the signal supplied to the first input terminal of the adder 7-2. The phase of the signal supplied to itself is shifted such that the component having the frequency of fy in the signal to be obtained has substantially the opposite phase to each other. In addition, the phase adjuster 4-3 includes a signal supplied from an output terminal of the mixer 5-3 to a second input terminal of the adder 7-3 and a first signal of the adder 7-3.
The phase of the signal supplied to itself is shifted so that the component having the frequency of fz in the signal supplied to the input terminal of the second signal has substantially the opposite phase.

On the other hand, a second input terminal of the mixer 5-1 has:
An AC signal having a frequency (fx-fc) is supplied from an output terminal of the oscillator 6-1. A second input terminal of the mixer 5-2 is supplied with an AC signal having a frequency (fy-fc) from an output terminal of the oscillator 6-2. An AC signal is supplied, and an AC signal having a frequency (fz-fc) is supplied to a second input terminal of the mixer 5-3 from an output terminal of the oscillator 6-3.

As a result, from the output end of the mixer 5-1,
A signal having a frequency of fx is output to a second input terminal of the adder 7-1 as a component of the sum of the signal output from the phase adjuster 4-1 and the AC signal generated by the oscillator 6-1. You.
From the output end of the mixer 5-2, a phase adjuster 4-2 is provided.
Is a signal having a frequency of fy as a sum component of the signal output from the adder 7 and the AC signal generated by the oscillator 6-2.
-2 to the second input terminal. Also, the mixer 5-
From the output terminal of the oscillator 3 as a component of the sum of the signal output from the phase adjuster 4-3 and the AC signal generated by the oscillator 6-3,
A signal having a frequency of fz is output to a second input terminal of the adder 7-3.

On the other hand, a first input terminal of the adder 7-1 has:
A desired wave and three interference waves are supplied from an output end of the distributor 1-3. Therefore, the adder 7-1 has its own first
And the addition result of the signals supplied to the second input terminal,
The signal supplied to the first input terminal of the adder 7-1 from which the first interference wave having the frequency fx has been substantially removed (that is, the desired wave and the second and third interference waves) Waves)
It outputs from its own output terminal to the first input terminal of the adder 7-2.

Then, the adder 7-2 separates the signal supplied from the adder 7-1 (that is, the desired wave, the second and third interfering waves) and the signal supplied from the mixer 5-2. A signal corresponding to the result of the addition is output to the first input terminal of the adder 7-3. The signal output by the adder 7-2 is obtained by substantially removing the second interference wave from the signal output by the adder 7-1. Further, the adder 7-3 outputs the signal supplied from the adder 7-2 (that is, the desired signal and the third signal).
And a signal corresponding to the result of adding the signal supplied from the mixer 5-3 and the signal supplied from the mixer 5-3.

The signal output from the output terminal of the adder 7-3 is obtained by substantially removing the third interference wave from the signal output from the adder 7-2, that is, the interference wave elimination device. Corresponds to a signal obtained by substantially removing the first, second, and third interfering waves from the signal supplied to the input terminal of. By the operation described above, the interference wave removing apparatus outputs a signal corresponding to a signal supplied to its own input terminal, in which at most three interference waves are substantially removed.

The configuration of the interference wave removing device is not limited to the above. For example, the value of n is arbitrary and need not be 3. Also, the desired wave need not be a CDMA signal. Also, the desired wave and the interference wave may be in the form of a digital signal.
-1 to 1-n, mixers 2-1 to 2-n and mixer 5-1
To 5-n, BPF3-1 to 3-n, and phase adjuster 4-1
~ 4-n, oscillators 6-1 ~ 6-n, adders 7-1 ~ 7-
n, a part or all of the functions of the detection units 8-1 to 8 -n and the control unit 9 are a DSP (Digital Signal Processor) or a CP
It may be performed by U (Central Processing Unit). Further, the mixers 2-1 to 2-n and 5-1 to 5-n
Some or all of the functions of the oscillators 6-1 to 6-n are A /
D (Analog-to-Digital) converter, DSP and D / A (D
digital-to-Analog) converter.
Further, the detection units 8-1 to 8-n do not need to detect or rectify the AC signal applied to their own input terminals. For example, the detection units 8-1 to 8-n perform A / D conversion on the AC signals applied to their own input terminals. Alternatively, the conversion result may be supplied to the control unit 9.

The passbands of the BPFs 3-1 to 3-n do not need to be identical to each other, and the frequency of the interfering wave to be removed by the mixers 2-1 to 2-n is converted to the BPF.
After passing through any of the PFs 3-1 to 3-n, the frequency of the disturbing wave is converted by one of the mixers 5-1 to 5-n by the mixers 2-1 to 2-n. BP as long as it is substantially returned to the previous frequency
F3-1 to 3-n may include ones having different passbands. Also, BPF3-1-3
The widths of the -n passbands need not be identical to each other.

The control unit 9 controls the oscillators 6-1 to 6-1 so that the BPFs 3-1 to 3-n pass different interference waves from each other.
The method of determining the frequency of the AC signal to be generated in each of the 6-n is arbitrary. Therefore, for example, the control unit 9
While supplying a control signal for continuously increasing the frequency from the lower limit to the upper limit of the band of the desired wave to the control input terminal of the oscillator 6-k, the intensity of the AC voltage detected by the detection unit 8-k substantially increases. It is repeatedly determined whether or not the maximum has been reached, and the timing of determining that the maximum has been reached (the number of the timings is a maximum of n
), The frequency of the AC signal generated by the oscillator 6-k may be stored. In this case, the control unit 9 may determine that the stored maximum n frequencies are the frequencies of the AC signals generated by the oscillators 6-1 to 6-n, respectively. In this case, the interference wave removing device only needs to include at least one detector.

Further, the phase adjusters 4-1 to 4-n need not be arranged as described above, and the phase adjusters 4-1 to 4-n add the phase of the signal supplied to the second input terminal of the adder 7-k to the adder 7-k. Of the signal supplied to the second input terminal of the adder 7-k of the signal supplied to the first input terminal of the adder 7-k, They may be arranged at any positions as long as they have a reversed phase relationship. Therefore, as shown in FIG. 2, for example, the phase adjuster 4-k is connected to the output terminal of the mixer 2-k.
Is connected, and the output terminal of the phase adjuster 4-k is BP
It may be connected to the input terminal of F3-k, and the output terminal of BPF3-k may be connected to the first input terminal of mixer 5-k.

Further, the phase of the signal supplied to the second input terminal of the adder 7-k and the phase of the signal supplied to the first input terminal of the adder 7-k, If the signal supplied to the input terminal 2 and the phase of the component having substantially the same frequency have a substantially opposite phase relationship to each other, the phase adjuster 4-
k is not always necessary, and in this case, the phase adjuster 4-
k to be connected to the input terminal, and a phase adjuster 4-k
It is only necessary that the output terminal of the first circuit be short-circuited with the portion to be connected.

The phase adjuster 4-k includes an adder 7-k
Of the signal supplied to the second input terminal of the adder 7-
k of the signals supplied to the first input terminal of the adder 7-k
Of the signal supplied to the second input terminal of the second signal and the phase difference between the signal and the phase of the component having substantially the same frequency, so that the signals passing through the second input terminal have a substantially opposite phase relationship with each other. May be automatically controlled.

This interfering wave removing apparatus includes an adder 7-
In place of k, a subtractor having first and second input terminals and an output terminal is provided, and the first input terminal, the second input terminal, and the output terminal of the adder 7-k are to be connected. The first input terminal, the second input terminal, and the output terminal of the subtracter may be connected to the point. This subtractor has its own first and second
A signal having an instantaneous value corresponding to the difference between the instantaneous values of the signals supplied to the input terminals is output from its own output terminal. However, in this case, the phase adjuster 4-k includes the adder 7
The phase of the signal supplied to the second input terminal of the subtractor instead of -k and the signal supplied to the first input terminal of the subtractor, which is supplied to the second input terminal of the subtractor The signal passing through itself is phase-shifted such that the phase of the signal having the same frequency as that of the signal having the same frequency is substantially in phase with each other.

If the frequency of the interference wave to be removed is known, the frequency of the AC signal generated by oscillators 6-1 to 6-n may be fixed. Also, the oscillator 6-1
6-n may be manually changed, and the control signal supplied to the control input terminals of the oscillators 6-1 to 6-n may be controlled by the interference wave removing device. It may be supplied from outside.

Further, this interfering wave removing apparatus is provided with a distributor 1-
From k, a mixer 2-k, a BPF 3-k, a phase adjuster 4-
k, an amplifier for compensating signal attenuation may be provided at an arbitrary position in a signal path from the mixer 5-k to the adder 7-k. More specifically, for example, as shown in FIG. 3, an input terminal and an output terminal are provided, the input terminal is connected to the output terminal of the BPF3-k, and the output terminal is connected to the input terminal of the phase adjuster 4-k. What is necessary is just to provide an amplifier. In this case, as shown in the figure, the detection units 8-1 to 8-8
For -n, the strength of the signal output to the output terminal of each of these amplifiers may be detected instead of the strength of the signal output to the output terminal of each of the BPFs 3-1 to 3-n.

The mixer 2-k outputs a signal having a frequency substantially equal to the sum of the frequencies of the signals supplied to its first and second input terminals from its own output terminal. It may be. In this case, the mixer 5-k outputs from its output terminal a signal having a frequency substantially equal to the difference between the frequencies of the respective signals supplied to its first and second input terminals. I just need.

Although the signal elimination apparatus according to the present invention has been described above, the signal elimination apparatus according to the present invention can be realized by using a general computer system without using a dedicated system. For example, by installing the program for executing the above-described operation from a medium (a floppy disk, a CD-ROM, or the like) storing the program for executing the above-described operation in a personal computer, an interference wave removing apparatus that executes the above-described processing is configured. be able to.

The medium for supplying the program to the computer may be a communication medium (medium for temporarily and fluidly holding the program, such as a communication line, a communication network, or a communication system). For example, the program may be posted on a bulletin board (BBS) of a communication network and distributed via the network. Distribution via a network may be performed by transmitting a modulated wave obtained by modulating a carrier wave by the program. Then, by starting this program and executing it in the same manner as other application programs under the control of the OS, the above-described processing can be executed.

When the OS shares a part of the processing,
Alternatively, when the OS constitutes a part of one component of the present invention, the recording medium may store a program excluding the part. Also in this case, in the present invention, it is assumed that the recording medium stores a program for executing each function or step executed by the computer.

[0070]

As described above, according to the present invention, a signal elimination apparatus and a signal elimination method for eliminating an interference wave having an unspecified frequency without deteriorating communication quality are realized.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a basic configuration of an interference wave removing apparatus according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a modified example of the interference wave removing apparatus of FIG.

FIG. 3 is a block diagram showing a modified example of the interference wave removing apparatus of FIG.

[Explanation of symbols]

 1-1 to 1-n distributor 2-1 to 2-n mixer 3-1 to 3-n BPF 4-1 to 4-n phase adjuster 5-1 to 5-n mixer 6-1 to 6 -N oscillator 7-1 to 7-n adder 8-1-1 to 8-n detector 9 controller

Claims (7)

[Claims] 1. A band-pass filter that passes a component whose frequency belongs to a predetermined filter pass band in a signal supplied to itself, and performs frequency conversion on a signal to be processed and is included in the signal to be processed. A first frequency shifter that supplies the signal to be processed subjected to frequency conversion to the band-pass filter so that the frequency of the component to be removed belongs to the filter pass band; and a component that has passed through the band-pass filter. So that the frequency of the component is substantially equal to the frequency of the component to be removed included in the signal to be processed before being subjected to the frequency conversion by the first frequency shifter. A second frequency shifter; a component to be removed included in a signal to be processed before being subjected to frequency conversion by the first frequency shifter; and a second frequency shifter. A component remover that removes the component to be removed from a signal to be processed that has not been subjected to frequency conversion by the first frequency shifter, based on the component that has undergone frequency conversion by the frequency converter. A signal eliminator characterized by the above-mentioned. 2. The component remover according to claim 1, wherein the instantaneous value of the signal to be processed before being subjected to frequency conversion by said first frequency shifter and frequency-converted by said second frequency shifter. A signal having an instantaneous value corresponding to the sum of the instantaneous value of the component and the instantaneous value is generated by removing the component to be removed from the signal to be processed before being subjected to frequency conversion by the first frequency shifter. An adder for causing the phase of the component subjected to frequency conversion by the second frequency shifter to be included in a signal to be processed before being subjected to frequency conversion by the first frequency shifter. The signal according to claim 1, further comprising: a phase adjuster that adjusts a result of the frequency conversion by the second frequency shifter so that the phase is substantially opposite to a phase of the target component. Removal device. 3. The component remover according to claim 1, wherein the instantaneous value of the signal to be processed before being subjected to the frequency conversion by the first frequency shifter and the frequency conversion performed by the second frequency shifter. A signal having an instantaneous value corresponding to the difference between the component and the instantaneous value is generated as a signal obtained by removing the component to be removed from a signal to be processed before being subjected to frequency conversion by the first frequency shifter. A subtractor, wherein the phase of the component subjected to frequency conversion by the second frequency shifter is included in a signal to be processed before being subjected to frequency conversion by the first frequency shifter. The signal removal according to claim 1, further comprising: a phase adjuster that adjusts a result of frequency conversion by the second frequency shifter so that the result is substantially in phase with the phase of the target component. apparatus. 4. A removal target component detection that specifies a frequency of the removal target component and generates a local oscillation signal having a frequency corresponding to the sum or difference between the specified frequency and a frequency belonging to the predetermined filter pass band. Means, the first frequency shifter, the component of the result of heterodyning the signal to be processed and the local oscillation signal belongs to the filter pass band, the frequency of the component to be processed A first mixer that supplies the signal as a signal to the band-pass filter, wherein the second frequency shifter is configured to perform the first mixer among the results of heterodyne mixing the component that has passed through the band-pass filter and the local oscillation signal. A component having a frequency substantially equal to the frequency of the component to be removed included in the signal to be processed before being subjected to frequency conversion by the frequency shifter
4. The signal removal device according to claim 1, further comprising a second mixer that generates a result of performing frequency conversion on a component that has passed through the band-pass filter. 5. 5. The apparatus according to claim 1, wherein said component to be removed is a first local scanning signal for sweeping a band corresponding to a sum or a difference between a band including the signal to be processed and a frequency belonging to the filter pass band. Scanning means for supplying to the frequency shifter, and frequency identification means for identifying the frequency of the component to be removed based on the intensity of the component passing through the band-pass filter, 5. The signal removing device according to 4. 6. A first frequency shifting step of subjecting a signal to be processed to frequency conversion so that the frequency of a component to be removed included in the signal to be processed belongs to a predetermined filter pass band; A band filter step of extracting a component whose frequency belongs to a predetermined filter pass band, of the signal subjected to frequency conversion in the frequency shift step, and subjecting the component extracted in the band filter step to frequency conversion, A second frequency shift step of making the frequency of the first frequency shift step substantially equal to the frequency of the component to be removed included in the signal to be processed before being subjected to the frequency conversion in the first frequency shift step; A removal target component included in a signal to be processed before being subjected to frequency conversion in the first frequency shift step; And a component removing step of removing the component to be removed from a signal to be processed which has not been subjected to the frequency conversion in the first frequency shift step based on the component subjected to the frequency conversion in the step. A signal removal method characterized by the above-mentioned. 7. A computer, comprising: a band-pass filter for passing a component having a frequency belonging to a predetermined filter pass band in a signal supplied to itself; a computer for performing frequency conversion on a signal to be processed; A first frequency shifter for supplying the frequency-converted signal to be processed to the band-pass filter so that the frequency of the component to be removed included in the band-pass filter is included in the filter; The passed component is subjected to frequency conversion, and the frequency of the component is substantially equal to the frequency of the component to be removed included in the signal to be processed before being subjected to frequency conversion by the first frequency shifter. A second frequency shifter, a component to be removed included in a signal to be processed before being subjected to frequency conversion by the first frequency shifter, A component remover for removing the component to be removed from a signal to be processed which has not been subjected to frequency conversion by the first frequency shifter based on the component subjected to frequency conversion by the second frequency shifter; And a computer-readable recording medium on which a program for causing the computer to function is recorded.