JP2000261345A - Narrow-band interference wave limiting device and communication equipment using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a narrow-band interference wave limiting device where the deterioration of a spreading signal due to involution is small in spite of the use of a magnetostatic filter. SOLUTION: A diffusion signal dividing means 11 divides a spreading signal into four small bands, a narrow-band interference wave limiting means 12 limits narrow-band interference waves with magnetostiatic filters MSW1 to 4 in each small band, and a spreading signal synthesizing means 13 synthesizes respective small bands in which the narrow-band interference waves are limited. Since involution that occurs when the narrow-band interference waves are limited is limited to each small band so as not to affect other small bands in this way, the deterioration range of a spreading signal due to the involution is limited.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a narrow-band interference wave limiting device and a communication device using the same, and more particularly to a narrow-band interference wave limiting device for limiting the level of a narrow-band interference wave mixed into a frequency band occupied by spread signals in spread spectrum communication. The present invention relates to a band interference wave limiting device and a communication device using the same.

[0002]

2. Description of the Related Art With the spread of spread spectrum communication in recent years, a problem has arisen that a narrow band interference wave having a high signal level is mixed in a frequency band occupied by a spread signal, thereby deteriorating communication quality. As a countermeasure, a device for limiting a narrow-band interference wave mixed into a spread signal is required.

FIG. 12 shows a conventional narrow band interference wave limiting device. The basic configuration of the narrow-band interference wave limiting device 1 shown in FIG. 12 is disclosed in Japanese Patent Application Laid-Open No. 9-214397.

In FIG. 12, a narrow band interference wave limiting device 1 is shown.
Is composed of an input terminal 2, an amplification factor variable amplifier 3 and a magnetostatic wave filter 4 connected in series to the input terminal 2, and an output terminal 5 connected to the magnetostatic wave filter 4. Here, the magnetostatic wave filter 4 has a function of frequency-selectively limiting a signal having an amplitude equal to or higher than the saturation level within the band to the saturation level. In other words, it is possible to limit a signal having a frequency that is equal to or higher than the saturation level of the magnetostatic wave filter 4 on the frequency axis to the saturation level. Conversely, level restriction is not performed on a signal having a frequency that does not reach the saturation level of the magnetostatic wave filter 4. Note that the magnetostatic wave filter 4 is not a frequency-selective level limit,
There is also insertion loss over the entire band, and it is attenuated by that amount over the entire frequency band. Next, when the signal is input, the amplification factor variable amplifier 3 controls the amplification so that the level of the spread signal in the signal substantially matches the saturation level of the magnetostatic wave filter 4. At this time, if a narrow-band interference wave having a level higher than the level of the spread signal is mixed in the signal, it is also amplified at the same amplification factor.

In the narrow-band interference wave limiting device 1 configured as described above, when a spread signal including a narrow-band interference wave is input from the input terminal 2, the level of the spread signal is adjusted by the variable amplification factor amplifier 3 to, for example, static. The whole is amplified to reach the saturation level of the magnetic wave filter 4. When the amplified signal is input to the magnetostatic wave filter 4, the signal above the saturation level is frequency-selectively limited. That is, if a narrow-band interference wave higher than the saturation level of the magnetostatic wave filter 4 is mixed, the saturation level of the magnetostatic wave filter 4 is limited to the level of the spread signal in this case. In this manner, the level of the narrowband interference wave is limited to, for example, the level of the spread signal, and is output from the output terminal 5.

[0006]

By the way, in the narrow-band interference wave limiting device 1 shown in FIG. 12, when the level of the narrow-band interference wave is much larger than the saturation level of the magnetostatic wave filter, There is a problem that the signal below the saturation level in the frequency band near the restricted narrow-band interference wave, that is, the level of the spread signal itself drops abnormally (this is called entrainment).

FIG. 13 shows frequency characteristics of a signal before and after passing through the magnetostatic wave filter 4. Here, FIG.
FIG. 13A shows the state before entering the magnetostatic wave filter 4.
Is the frequency characteristic of the signal after passing through the magnetostatic wave filter 4. As shown in FIG. 13A, a narrow-band interference wave n is mixed in the occupied frequency band of the spread signal s. Note that r
Indicates the saturation level of the magnetostatic wave filter 4, and the level of the narrow band interference wave n is considerably higher than the saturation level of the magnetostatic wave filter 4. Then, as shown in FIG. 13B, after passing through the magnetostatic wave filter 4,
Not only is the level of the narrow-band interference wave n limited to the saturation level r of the magnetostatic wave filter 4, but entrainment i occurs in a frequency band near the narrow-band interference wave n. The entrapment i has the property of increasing as the level of the narrow-band interference wave n is greatly restricted. Then, there is a problem that the quality of the spread signal s is degraded due to the occurrence of the entanglement i.

In the narrow band interference wave limiting device 1 shown in FIG. 12, when two or more narrow band interference waves are mixed in the occupied frequency band of the spread signal, the magnetostatic wave filter 4 is switched off. Inter-modulation distortion caused by narrow-band interference waves when passing through
rtion, IMD).

FIG. 14 shows the frequency characteristics of a signal before and after passing through the magnetostatic wave filter 4 when two narrow band interference waves are mixed in the occupied frequency band of the spread signal. Here, FIG. 14A shows the frequency characteristics of the signal before entering the magnetostatic wave filter 4 and FIG. 14B shows the frequency characteristics of the signal after passing through the magnetostatic wave filter 4. 14, the same parts as those in FIG. 13 are denoted by the same reference numerals, and description thereof will be omitted. As shown in FIG. 14A, two narrowband interference waves n1 having the same level and different frequencies are mixed in the occupied frequency band of the spread signal s. Then, as shown in FIG. 14 (b), after passing through the magnetostatic wave filter 4, the levels of the two narrowband interference waves n1 are limited to the saturation level r of the magnetostatic wave filter 4, but the surroundings are limited. Intermodulation distortions n2 and n3 occur in the frequency band of. Then, there is a problem that the quality of the spread signal s deteriorates due to the generation of the intermodulation distortions n2 and n3. In addition, even when two or more narrow band interference waves are mixed, entrainment occurs,
Since the drawing is complicated, it is omitted in FIG.

Accordingly, the present invention provides a narrow-band interference wave limiting device which can limit a narrow-band interference wave and, despite the use of a magnetostatic wave filter, has little deterioration in the quality of a spread signal due to entrainment or intermodulation distortion. And a communication device using the same.

[0011]

In order to achieve the above object, a narrow band interference wave limiting apparatus according to the present invention comprises a spread signal dividing apparatus for dividing an input spread signal into a plurality of small bands having different frequency bands. Means, narrow-band interference wave limiting means comprising a narrow-band interference wave limiting circuit using a plurality of magnetostatic wave filters that respectively limit narrow-band interference waves included in the spread signal divided for each of the plurality of small bands, A spread signal synthesizing means for synthesizing a spread signal in which a narrow band interference wave is restricted for each of the plurality of small bands.

Further, the narrow-band interference wave limiting device of the present invention
The spread signal synthesizing unit synthesizes a spread signal in which narrow-band interference waves are restricted for each of the plurality of small bands, limited to each of the plurality of small bands.

Further, the narrow-band interference wave limiting device of the present invention comprises:
Interfering wave band selecting means for dividing the input spread signal into two frequency bands that do not overlap each other and selecting the higher signal level a plurality of times to select a small band having the highest signal level; A narrow-band interference wave limiting unit having a narrow-band interference wave limiting circuit using a magnetostatic wave filter for limiting a narrow-band interference wave included in the small band selected by the interference wave band selection unit; A spread signal synthesizing means for synthesizing a spread signal of a narrow band in which the narrow-band interference wave is restricted with a spread signal of a frequency band excluded by the means.

Further, the narrow-band interference wave limiting device of the present invention comprises:
The spread signal synthesizing unit synthesizes the spread signal of the frequency band excluded by the spread signal selecting unit with the spread signal of the narrow band in which the narrow band interference wave is limited, limited to the small band. Features.

Further, the narrow-band interference wave limiting device of the present invention comprises:
The narrow-band interference wave limiting circuit includes a magnetostatic wave filter that frequency-selectively limits a signal of a certain level or more.

Further, the narrow-band interference wave limiting device of the present invention comprises:
The narrow-band interference wave limiting circuit distributes an input signal to two, and a static signal for making a level difference between a narrow-band interference wave and a spread signal included in the two distributed signals different from each other. Level difference creating means using a magnetic wave filter;
Signal combining means for combining two signals having different level differences between the narrow-band interference wave and the spread signal by matching the levels of the narrow-band interference wave and inverting the phases of the two signals is provided.

Further, a communication apparatus according to the present invention uses any one of the above narrow band interference wave limiting apparatuses.

With such a configuration, in the narrow-band interference wave limiting device of the present invention, the narrow-band interference wave is limited. Deterioration of the quality of the spread signal can be prevented.

Further, in the communication device of the present invention, it is possible to prevent deterioration of communication quality.

[0020]

FIG. 1 shows an embodiment of the narrow-band interference wave limiting device of the present invention. In FIG. 1, the same or equivalent parts as those in FIG.

In FIG. 1, a narrow band interference wave limiting device 10
Is constructed by sequentially connecting a spread signal dividing means 11, a narrow band interference wave limiting means 12, and a spread signal synthesizing means 13 between a variable amplification factor amplifier 3 and an output terminal 5.

The spread signal dividing means 11 includes a signal distributor 14 and four band-pass filters BPF1, BPF2, BPF3, BPF connected to the output of the signal distributor 14.
It is composed of PF4. Four bandpass filters B
Each of the frequency bands W1, W2, W3, and W4 of PF1, BPF2, BPF3, and BPF4 is referred to as a small band. It is configured.

The narrow-band interference wave limiting means 12 includes four band-pass filters BPF1 of the spread signal dividing means 11,
4 connected to BPF2, BPF3 and BPF4 respectively
It is composed of limiter type magnetostatic wave filters MSW1, MSW2, MSW3 and MSW4 which are two narrow band interference wave limiting circuits. Here, four magnetostatic wave filters MSW
1, MSW2, MSW3, and MSW4 have a function of frequency-selectively limiting a signal of a certain level or more, specifically, a saturation level or more.

The spread signal synthesizing means 13 comprises four magnetostatic wave filters MSW1, MSW2, MSW3, MSW
4 comprises a signal combiner 15 connected to the output of the signal synthesizer 15.

FIG. 2 shows the frequency characteristics of the signal before and after passing through the narrow-band interference wave limiting means 12 of the narrow-band interference wave limiting device 10 configured as described above. explain. 2 (a) shows the frequency characteristics of the signal before entering the narrow-band interference wave limiting means 12, and FIG. 2 (b) shows the frequency characteristics of the signal after passing through the spread signal combining means 13.

First, the signal output from the variable amplification factor amplifier 3 is divided into four signals by the signal distributor 14 of the spread signal dividing means 11, and as shown in FIG. , BPF2, BPF3, BPF4,
The signals are divided into signals of only the small bands W1, W2, W3, and W4. Note that the gaps between the small bands in FIG. 2A are provided for the sake of convenience in order to clarify the width of each small band, and the same applies hereinafter.

The signals divided into four small bands W1, W2, W3 and W4 are respectively applied to the magnetostatic wave filters MSW1, MSW2, MSW3 and MSW of the narrow band interference wave limiting means 12.
At 4, narrow band interference above the saturation level is limited. At this time, since the narrow band interference wave n is mixed only in the signal of the small band W2, the narrow band interference wave n is limited only by the magnetostatic wave filter MSW2, and the other magnetostatic wave filters are not limited. Therefore, entrainment i occurs only in the signal passing through the magnetostatic wave filter MSW2, and does not reach other small bands.

Then, the four magnetostatic wave filters MSW1,
The signals that have passed through MSW2, MSW3, and MSW4 are combined by the signal combiner 15 of the spread signal combining means 13 and
As shown in (b), the entanglement i occurs only in the small band W2.
Is output.

As described above, the narrow-band interference wave limiting device 10 can limit the level of the narrow-band interference wave mixed in the occupied frequency band of the spread signal. Moreover, despite the use of a magnetostatic wave filter in the narrow-band interference wave limiting circuit, the frequency band in which the entrainment occurs
This can be limited to a small band in which a narrow-band interference wave has been mixed, and deterioration of the quality of a spread signal due to entrainment can be reduced.

Next, a case where two narrow band interference waves are mixed in the occupied frequency band of the spread signal is shown in FIG.
The frequency characteristics of signals before and after passing through the narrow-band interference wave limiting circuit 12 are shown, and will be described with reference to FIGS. 3A shows the frequency characteristics of the signal before entering the narrow-band interference wave limiting means 12, and FIG. 3B shows the frequency characteristics of the signal after passing through the spread signal combining means 13.

First, the signal output from the variable amplification factor amplifier 3 is divided into four signals by the signal distributor 14 of the spread signal dividing means 11, and as shown in FIG. , BPF2, BPF3, BPF4,
The signals are divided into signals of only the small bands W1, W2, W3, and W4.

The signals divided into the four small bands W1, W2, W3 and W4 are respectively applied to the magnetostatic wave filters MSW1, MSW2, MSW3 and MSW of the narrow band interference wave limiting means 12.
At 4, narrow band interference above the saturation level is limited. At this time, since the two narrow-band interference waves n1 exist separately in small bands W1 and W2, the narrow-band interference waves n1 are limited by the magnetostatic wave filters MSW1 and MSW2, and the limitation is not achieved by the other magnetostatic wave filters. I can't. Moreover, the small bands W1 and W
Since only one narrowband interference wave n1 exists in each of the filters 2, no intermodulation distortion occurs in the magnetostatic wave filters MSW1 and MSW2. Therefore, the magnetostatic wave filter M
The signal passing through SW1 and MSW2 limits the narrow-band interference wave n1 to the saturation level r.

Then, the four magnetostatic wave filters MSW1,
The signals that have passed through MSW2, MSW3, and MSW4 are combined by the signal combiner 15 of the spread signal combining means 13, and
As shown in (b), a signal having no intermodulation distortion is output.

As described above, the narrow-band interference wave limiting device 10 can limit the levels of two narrow-band interference waves mixed in the occupied frequency band of the spread signal. In addition, in the case where two narrow band interference waves are divided into different small bands, the occurrence of intermodulation distortion can be prevented even though a magnetostatic wave filter is used in the narrow band interference wave limiting circuit. . As a result, deterioration of the quality of the spread signal can be reduced.

FIG. 4 shows the frequency characteristics of a signal before and after passing through the narrow-band interference wave limiting circuit 12 when two narrow-band interference waves are mixed into one small band. This is shown and considered with reference to FIGS. FIG.
FIG. 4A shows a state before entering the narrow-band interference wave limiting circuit 12.
(B) is a frequency characteristic of the signal after passing through the spread signal synthesizing means 13.

First, the signal output from the variable amplification factor amplifier 3 is divided into four signals by the signal distributor 14 of the spread signal dividing means 11, and as shown in FIG. , BPF2, BPF3, BPF4,
The signals are divided into signals of only the small bands W1, W2, W3, and W4.

The signals divided into four small bands W1, W2, W3 and W4 are respectively applied to the magnetostatic wave filters MSW1, MSW2, MSW3 and MSW of the narrow band interference wave limiting means 12.
At 4, narrow band interference above the saturation level is limited. At this time, the two narrow-band interference waves n1 are both small-band W2
, The narrow-band interference wave n1 is limited only by the magnetostatic wave filter MSW2, and is not limited by other magnetostatic wave filters. However, since two narrow band interference waves n1 are mixed in the small band W2, the magnetostatic wave filter M
In SW2, intermodulation distortion that extends outside the small band W2 occurs. Moreover, after passing through the magnetostatic wave filter MSW2, the signal is not limited to the small band W2 and is combined with another frequency band by the signal combiner 15. Therefore, as shown in FIG. 4B, the intermodulation distortions n2 and n3 generated in the magnetostatic wave filter MSW2 are not only generated in the small band W2 but also in the small band W1.
Or W3, and a part of the effect of level-limiting the narrow-band interference wave n1 is cancelled.

FIG. 5 shows another embodiment of the narrow-band interference wave limiting device of the present invention for solving such a problem. 5, the same or equivalent parts as those in FIG. 1 are denoted by the same reference numerals, and the description thereof will be omitted.

In FIG. 5, the narrow-band interference wave limiting device 20
Is composed of four magnetostatic wave filters MS.
Four bandpass filters BPF5, BPF6, BPF connected to the outputs of W1, MSW2, MSW3, MSW4
7, BPF8 and four band-pass filters BPF5, BPF
It comprises a signal combiner 15 connected to the outputs of PF6, BPF7 and BPF8. The passbands of the four bandpass filters BPF5, BPF6, BPF7 and BPF8 are set to be the same as the four bandpass filters BPF1, BPF2, BPF3 and BPF4 of the spread signal dividing means 11, respectively. Have been.

FIG. 6 shows the frequency characteristics of the signal before and after passing through the narrow-band interference wave limiting means 12 for the narrow-band interference wave limiting device 20 configured as described above. explain. 6A shows the frequency characteristics of the signal before entering the narrow-band interference wave limiting means 12, and FIG. 6B shows the frequency characteristics of the signal after passing through the spread signal combining means 21.

The narrow-band interference wave limiting device 20 is the same as the narrow-band interference wave limiting device 10 until the signal passes through the narrow-band interference wave limiting means 12, and only the signal output from the magnetostatic wave filter MSW2 has a saturation level r. The narrow-band interference wave n1 and the intermodulation distortions n2 and n3 whose levels are limited to the maximum exist. Then, in the spread signal synthesizing means 21, the small band W of the signals output from the magnetostatic wave filter MSW2 is output.
Signals other than 2 are removed by the band-pass filter BPF6. Therefore, the intermodulation distortion n2 on the low frequency side and the intermodulation distortion n3 on both sides are removed, and the signal output from the band-pass filter BPF6 includes the level-limited narrowband interference wave n1 and the intermodulation distortion n2 on the high frequency side. Only remains. As a result, after passing through the spread signal synthesizing means 21, a signal having intermodulation distortion is output only in the small band W2 as shown in FIG. 6B.

As described above, the narrow-band interference wave limiting device 20 can limit the level of the narrow-band interference wave mixed into the occupied frequency band of the spread signal. In addition, despite the use of a magnetostatic wave filter in the narrow band interference wave limiting circuit, even when two narrow band interference waves are mixed in the same small band, the occurrence of intermodulation distortion is limited to the small band. However, it is possible to prevent intermodulation distortion from spreading to other small bands. As a result, deterioration of the quality of the spread signal can be reduced.

In the above two embodiments, the frequency band occupied by the spread signal is divided into four sub-bands to limit the level of narrow-band interference waves. The effect is not limited to this, and as the number of divisions is increased and the bandwidth of the small band is reduced, the influence of signal deterioration due to entrainment by the magnetostatic wave filter and intermodulation distortion can be reduced.

FIG. 7 shows still another embodiment of the narrow-band interference wave limiting device of the present invention. 7, the same or equivalent parts as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted.

In the narrow-band interference wave limiting device 30 shown in FIG. 7, a signal distributor 31 is connected to the variable amplification factor amplifier 3, and its output is supplied to band-pass filters BPF9 and BPF10.
It is connected to the. Bandpass filters BPF9 and BPF
The outputs of 10 are connected to switches SW1 and SW2, respectively, as well as to a level comparator 32. One output of the switch SW1 is connected to the signal distributor 34, and the other output is connected to the signal combiner 33. One output of the switch SW2 is connected to the signal combiner 33, and the other output is connected to the signal distributor.

The output of the signal distributor 34 is connected to bandpass filters BPF11 and BPF12. Outputs of the band-pass filters BPF11 and BPF12 are connected to switches SW3 and SW4, respectively, and are also connected to a level comparator 35. One output of the switch SW3 is connected to the signal combiner 39, and the other output is connected to the signal combiner 38. One output of the switch SW4 is connected to the signal synthesizer 38, and the other output is connected to the signal synthesizer 39.

The output of the signal distributor 36 is connected to bandpass filters BPF13 and BPF14. Outputs of the band-pass filters BPF13 and BPF14 are connected to switches SW5 and SW6, respectively, and also to a level comparator 37. One output of the switch SW5 is connected to the signal synthesizer 39, and the other output is connected to the signal synthesizer 38. One output of the switch SW6 is connected to the signal combiner 38, and the other output is connected to the signal combiner 39.

The output of the signal combiner 39 is a limiter type magnetostatic wave filter MSW5 which is a narrow band interference wave limiting circuit.
It is connected to the. On the other hand, the output of the signal combiner 33 is connected to the signal combiner 40 together with the output of the signal combiner 38.

The output of the signal combiner 40 is connected to the signal combiner 41 together with the output of the magnetostatic wave filter MSW5, and the output of the signal combiner 41 is connected to the output terminal 5.

In the narrow band interference wave limiting device 30, the interference wave band selecting means 42 is constituted by excluding the input terminal 2, the variable amplification factor amplifier 3, the magnetostatic wave filter MSW5, the signal combiner 41 and the output terminal 5. are doing. The magnetostatic wave filter MSW5 constitutes a narrow band interference wave limiting unit 43, and the signal combiner 41 constitutes a spread signal combining unit 44.

Here, the band-pass filters BPF9 and BP9
The frequency band of F10 coincides with the lower half and the higher half of the occupied frequency band of the spread signal, respectively. Also,
The frequency bands of the band-pass filters BPF11 and BPF12 coincide with the lower half and the higher half of the frequency band of the band-pass filter BPF9, respectively. Further, the frequency bands of the bandpass filters BPF13 and BPF14 are
They correspond to the lower half and the higher half of the frequency band of the bandpass filter BPF10, respectively.

FIG. 8 shows the relationship between the spread signal and the frequency band of each band-pass filter in the narrow-band interference wave limiting device 30 configured as described above.

First, the signal output from the variable amplification factor amplifier 3 is divided into two by a signal distributor 31 and two bandpass filters BPF9 and BPF10 are used for two intermediate bands on the high band side and the low band side. Is divided into Bandpass filter BP
The signals passing through F9 and BPF10 are input to switches SW1 and SW2, respectively,
2, the signal levels are compared, and the switches SW1 and SW2 are switched according to the magnitude. Specifically, as shown in FIG. 8, when the narrow-band interference wave n1 is mixed in the frequency band of the band-pass filter BPF9, the signal level of the signal passing through the band-pass filter BPF9 becomes higher. In this case, control is performed such that the output of the switch SW1 is connected to the signal distributor 34 and the output of the switch SW2 is connected to the signal combiner 33. As a result, the intermediate band signal mixed with the narrow-band interference wave n1 that has passed through the band-pass filter BPF9 is input to the signal distributor 34, and the intermediate band signal that has not mixed the narrow-band interference wave that has passed through the band-pass filter BPF10. The band signal is input to the signal combiner 33.

Next, the signal input to the signal distributor 34 is divided into two, and two band-pass filters BPF11,
In the BPF 12, the signal is further divided into two small bands on the high frequency side and the low frequency side. Bandpass filters BPF11 and BPF12
Are input to the switches SW3 and SW4, respectively, and the signal levels are compared by the level comparator 35, and the switches SW3 and SW4 are switched according to the magnitude. Specifically, as shown in FIG. 8, the narrow band interference wave n1 is set in the frequency band of the bandpass filter BPF12.
Is mixed, the bandpass filter BPF12
The signal level of the signal passing through becomes higher. And
In this case, control is performed so that the output of the switch SW3 is connected to the signal combiner 38 and the output of the switch SW4 is connected to the signal combiner 39. As a result, the small-band signal mixed with the narrow-band interference wave n1 that has passed through the band-pass filter BPF12 is input to the signal combiner 39, and the small-band signal that has not mixed the narrow-band interference wave that has passed through the band-pass filter BPF3. The band signal is input to the signal synthesizer 38.

Although the signal combiner 39 has four input terminals, the narrowband interference wave limiting device 30 has one input terminal.
That is, in this case, only a small-band signal mixed with the narrow-band interference wave passing through the band-pass filter BPF12 is input. Then, in the signal output from the signal combiner 39, the narrow-band interference wave n1 having a saturation level or higher is limited by the magnetostatic wave filter MSW5. At this time, n1 of the narrow band interference wave
Entanglement occurs at the front and rear frequencies, but this is limited to a small band that has passed through the band-pass filter BPF12. In other words, there is no spread signal to be involved outside the small band passing through the bandpass filter BPF12.

The signal whose narrow-band interference wave is limited by the magnetostatic wave filter MSW 5 is input to the signal combiner 41. on the other hand,
The intermediate band signal that has passed through the bandpass filter BPF10 is input to the signal combiner 40 via the signal combiner 33,
The small-band signal that has passed through the band-pass filter BPF 11 is input to a signal synthesizer 40 via a signal synthesizer 38 and synthesized, and further input to a signal synthesizer 41. Then, the signal combiner 41 combines the signal having passed through the band-pass filter 12 with the narrow-band interference wave n1 restricted and the signal in the other band, and outputs the combined signal to the output terminal 5. Therefore, the influence of the entanglement does not affect other than the small band passing through the band-pass filter BPF12.

In the above description, the case where the narrow band interference wave is mixed in the small band passing through the band pass filter BPF 12 has been described.
The same operation is performed even when a narrow band interference wave is mixed in a small band passing through the BPF 11, the BPF 13, and the BPF 14.

As described above, in the narrow-band interference wave limiting device 30, the narrow-band interference wave is limited by the magneto-static wave filter only in the small band where the narrow-band interference wave is mixed. It is possible to limit the entrapment due to the use to a small band where a narrow band interference wave exists. Further, since the small band in which the narrow band interference wave is not mixed is not passed through the magnetostatic wave filter, the group delay caused by passing through the magnetostatic wave filter can be minimized. As a result, in the narrow-band interference wave limiting device 30, deterioration of the quality of the spread signal can be reduced.

In the narrow band interference wave limiting device 30, the occupied frequency band of the spread signal is divided into four small bands by two-stage band division to limit the narrow band interference wave. May be applied to restrict the narrow-band interference wave in a narrower narrow band, in which case the influence of the entrainment by the magnetostatic wave filter can be further reduced.

In the spread signal synthesizing means 44 of the narrow band interference wave limiting device 30, bandpass filters corresponding to each small band are arranged in parallel between the magnetostatic wave filter MSW5 and the signal synthesizer 41, The narrow band interference wave is limited by controlling the signal comparators 35 and 37 so that the signal output from the magnetic wave filter MSW5 passes through the band pass filter having the same pass band as the small band in which the narrow band interference wave is limited. Limited to a small band, it can be combined with a spread signal of another band. As in the case of the narrow band interference wave limiting device 20, even when two narrow band interference waves are mixed into the same small band, The occurrence of intermodulation distortion can be limited to the small band, and the intermodulation distortion can be prevented from spreading to other small bands.

In each of the above embodiments, a limiter type magnetostatic wave filter is used as the narrow band interference wave limiting circuit. However, a cancel type narrow band interference wave limiting circuit may be used. .

FIG. 9 shows an example of a cancel type narrow band interference wave limiting circuit used in the narrow band interference wave limiting device of the present invention.

In FIG. 9, a narrow-band interference wave limiting circuit 50 is provided.
A signal divider 52 connected to the input terminal 51 as signal distribution means; a magnetostatic wave filter 53 serving as a limiter type level limiter connected to one output of the signal distributor 52; , An attenuator 54 and a phase shifter 55 connected in series to the other output of the signal distributor 52, and a signal synthesizer 56 connected to the magnetostatic wave filter 53 and the phase shifter 55.
And an output terminal 57 connected to the signal synthesizer 56. Among these, a part of the wiring between the magnetostatic wave filter 53 and the signal distributor 52 and the attenuator 54 has two inputs and two outputs and internally has two signal paths of a first path p1 and a second path p2. The level difference creating means 58 having the following configuration is constructed. The attenuator 54, the phase shifter 55, and the signal combiner 56 constitute a signal combining means 59.

Here, FIG. 10 shows the frequency characteristics of the signals flowing to the respective parts of the narrow-band interference wave limiting circuit 50, and the operation of the narrow-band interference wave limiting circuit 50 will be described by using them. In FIG. 10, the signal level on the vertical axis of the graph is dB.
it's shown.

First, FIG. 10A shows the frequency characteristic of the signal s0 input to the input terminal 51 of the narrow-band interference wave limiting circuit 50. As shown in FIG.
, A spread signal ss having a low level and spread over a wide band is input. Then, in the occupied frequency band of the spread signal ss, a narrow band interference wave n having a higher level than the spread signal ss is mixed. Here, the level difference between the narrowband interference wave n and the spread signal ss is d0.

The signal input to the input terminal 51 is divided into two equal parts by the signal distributor 52, and a signal s1 is output from one of the outputs.
The other output is output as a signal s3. FIG.
(B) shows the frequency characteristics of the signals s1 and s3. In FIGS. 10 (b) to 10 (e), the use of a code for the spread signal ss and the narrowband interference wave n complicates the drawing, so that the code is omitted. In FIG. 10B,
The spread signal ss and the narrow-band interference wave n are divided into two equal parts,
That is, the level is reduced by at least 3 dB.
However, the level difference between the narrowband interference wave n and the spread signal ss is d
It remains at 0 and has not changed.

Next, in the first path p1, the signal s
1 is input to the magnetostatic wave filter 53. In the magnetostatic wave filter 53, the saturation level r is set to be lower than the level of the narrow band interference wave n of the signal s1 by about 2 to 6 dB. Conversely, the signal s0 input to the signal distributor 52 has a level of the narrowband interference wave n of 2 to 6 dB lower than the saturation level r at the stage of input to the magnetostatic wave filter 53.
It is necessary to adjust the level in advance using a variable amplification factor amplifier or the like so as to increase the level. In FIG. 10B, the saturation level r of the magnetostatic wave filter 53 is indicated by a dashed line. Then, the saturation level r of the magnetostatic wave filter 53
And the level difference between the spread signal ss and the spread signal ss is d1 smaller than d0.

In the magnetostatic wave filter 53, the narrow-band interference wave n is limited to the saturation level r and output. FIG.
0 (c), the signal s output from the magnetostatic wave filter 53
2 shows the frequency characteristic of FIG. As shown in FIG. 10C, the level difference between the narrow-band interference wave n and the spread signal ss is d due to the level limitation of the narrow-band interference wave n by the magnetostatic wave filter 53.
It is 1. In FIG. 10C, the level of the spread signal ss is lower than in FIG. 10B, but this is due to the insertion loss existing in the magnetostatic wave filter 53 regardless of the frequency.

In the second path p2, the level of the narrow band interference wave n included in the signal s3 is attenuated by the attenuator 54 so as to match the level of the narrow band interference wave n included in the signal s2. You. The amount of attenuation of the attenuator 54 is determined from the saturation level of the magnetostatic wave filter 53 and the insertion loss. At this time, not only the narrowband interference wave n but also the spread signal s
s is attenuated by the same amount. Further, the phase shifter 55 shifts the phases of the two signals input to the signal combiner 56 through the first path p1 and the second path p2 such that the phases are opposite to each other. FIG. 10D shows the phase shifter 5
5 shows the frequency characteristics of the signal s4 output from FIG. FIG.
As shown in (d), the level of the narrowband interference wave n of the signal s4 matches the level of the narrowband interference wave n of the signal s2. The level difference between the narrow-band interference wave n and the spread signal ss remains unchanged at d0. As a result, the level of the spread signal of the signal s4 is lower than that of the spread signal of the signal s2.

The signal s2 that has passed through the first path p1 and the signal s4 that has passed through the second path p2 are combined equally by the signal combiner 56. At this time, the signal s
In the signal 2 and the signal s4, the narrow-band interference waves n are at the same level, and the phases are opposite to each other, so that they theoretically completely cancel each other. On the other hand, the spread signal s of the signal s2
s and the spread signal ss of the signal s4 have a level of 2 to 6 with respect to each other.
Due to the difference in dB, even if the phases are opposite to each other, they do not completely cancel each other, and a signal of a constant level remains. FIG. 10E shows a frequency characteristic of the signal s5 output from the signal combiner 56. As shown in FIG. 10 (e), although the spread signal ss remains only after being slightly lowered in level, there is no signal at the frequency where the narrowband interference wave n was present. In this way, the narrow-band interference wave n is limited.

As described above, the narrow-band interference wave limiting circuit 50 can greatly limit the level of the narrow-band interference wave mixed in the occupied frequency band of the spread signal.

In the narrow-band interference wave limiting circuit 50, the position where the phase shifter 55 is provided is not limited to the next stage of the attenuator 54, and the phase of the signal passing through the first path p1 and the second path p2 is not limited. May be provided in any of the two paths as long as the phase is reversed. Further, the phase shift amount of the phase shifter 55 is not necessarily set to 180 degrees, and the phase shift amount in each of the first path p1 and the second path p2 and the wiring of the two paths as a whole are taken into consideration. The value is determined so that the phase is reversed. When a signal distributor 52 or a signal combiner 56 such as a directional coupler having a function of shifting the phase of itself is used, the amount of phase shift is set in consideration of that. ,
Depending on conditions, a phase shifter as a single unit may not be required.

In the narrow-band interference wave limiting circuit 50, an attenuator 54 is provided in the second path p2 so that the levels of the narrow-band interference waves of the two signals input to the signal combiner 56 match. I have to. However, for example, the level of the signal s3 is transmitted to the signal distributor s1 such as a directional coupler.
If there is a function that can be distributed so as to be lower than the level of the signal sigma, or if the signal synthesizer itself has a function of making the level of the signal s4 lower than the level of the signal s2, a single attenuator may not be necessary. It is possible.

In the narrow-band interference wave limiting circuit 50, a limiter type magnetostatic wave filter is provided only on one of the two paths, but a limiter type magnetostatic wave filter may be provided on both of the two paths. It does not matter if the configuration is such that the level difference between the narrow band interference wave and the spread signal is generated by changing the level to be limited in the two paths, the same operation and effect as the narrow band interference wave limiting circuit 50 can be obtained. is there. Also, an enhanced type in which a spread signal having a level lower than the saturation level is limited (suppressed) in one or both of the two paths, and a level difference between the narrow band interference wave higher than the saturation level and the spread signal lower than the saturation level can be increased. May be provided, and has the same effect as the narrow-band interference wave limiting circuit 50. Further, a limiter type magnetostatic wave filter may be provided on one of the two paths, and an enhanced type magnetostatic wave filter may be provided on the other path.
The same operation and effect as those of the narrow-band interference wave limiting circuit 50 can be obtained.

FIG. 11 shows an embodiment of the communication apparatus of the present invention. A communication device 60 shown in FIG. 11 indicates a receiving unit of a spread spectrum communication device, and includes an antenna 61, a band-pass filter 62, an amplifier 63, and the narrow band interference wave limiting device of the present invention shown in FIG. 10, a despreader 64, a demodulator 65, and a signal processing circuit 66. Here, the antenna 61 includes a band-pass filter 62 and an amplifier 6.
3, sequentially connected to the narrow-band interference wave limiting device 10,
The narrow-band interference wave limiting device 10 includes a despreader 64 and a demodulator 65.
Are sequentially connected to the signal processing circuit 66.

In the communication device 60 configured as described above, the spread signal received by the antenna 61 is subjected to removal of the unnecessary frequency signal by the band-pass filter 62, amplified by the amplifier 63, and transmitted to the narrow-band interference wave limiting device. 10 is input. In the narrow-band interference wave limiting device 10, narrow-band interference waves mixed in the occupied frequency band of the spread signal are limited. The signal in which the narrow band interference wave is limited is despread by the despreader 64, demodulated by the demodulator 65, and processed by the signal processing circuit 66.
, And output as an audio signal, for example. The communication device 60 is omitted because it is not the main part of the present invention, but in practice, the frequency conversion of a received signal is often performed by connecting a mixer and a local oscillator to appropriate positions as necessary. .

As described above, by configuring the communication device 60 using the narrow-band interference wave limiting device 10 of the present invention, the narrow-band interference wave mixed into the occupied band of the spread spectrum signal is entangled. It is limited in a small state, and it is possible to prevent the communication quality of the communication device 60 from deteriorating.

In the communication device 60, the narrow band interference wave limiting device 10 is used, but the narrow band interference wave limiting device 20 shown in FIG. 5 and the narrow band interference wave limiting device 30 shown in FIG.
May be used, and have the same effect.

[0079]

According to the narrow-band interference wave limiting apparatus of the present invention, a spread signal dividing means for dividing an input spread signal into a plurality of small bands having different frequency bands, and a spread signal dividing means for dividing the spread signal into a plurality of small bands A narrow-band interference wave limiting means including a narrow-band interference wave limiting circuit using a plurality of magnetostatic wave filters for limiting the narrow-band interference waves included in the spread signal, and a narrow-band interference wave for each of a plurality of small bands. By comprising a spread signal synthesizing means for synthesizing the limited spread signal, the narrow band interference wave included in the occupied frequency band of the spread signal is limited,
Despite the use of the magnetostatic wave filter, it is possible to prevent the quality of the spread signal from deteriorating due to the entanglement.

Further, the spread signal synthesizing means synthesizes the spread signal in which the narrow-band interference wave is restricted for each of the plurality of small bands only for each of the plurality of small bands, thereby forming the spread signal due to the intermodulation distortion. Quality deterioration can also be prevented.

Further, according to the narrow-band interference wave limiting device of the present invention, dividing the input spread signal into two non-overlapping frequency bands and selecting the higher signal level is repeated a plurality of times. And a narrow band interference wave using a magnetostatic wave filter for limiting a narrow band interference wave included in the small band selected by the interference band selection means. A narrow-band interference wave limiting means having a limiting circuit, and a spread signal synthesizing means for synthesizing a narrow-band interference wave-limited small-band spread signal to a spread signal of a frequency band excluded by the interference wave band selection means. Accordingly, narrow-band interference waves included in the occupied frequency band of the spread signal can be limited, and the quality of the spread signal can be prevented from deteriorating due to the entanglement. Further, the band passing through the magnetostatic wave filter can be limited to a necessary minimum, and unnecessary deterioration of the spread signal caused by passing through the magnetostatic wave filter can be prevented.

Further, the spread signal synthesizing means limits the spread signal of the narrow band in which the narrow band interference wave is limited to the spread signal of the frequency band excluded by the spread signal selecting means to the small band. By combining the signals, the deterioration of the quality of the spread signal due to the intermodulation distortion can be prevented.

In the narrow band interference wave limiting device of the present invention, the same effect can be obtained by using not only a limiter type magnetostatic wave filter but also a cancel type narrow band interference wave limiting circuit.

In the communication device of the present invention, the use of the narrow-band interference wave limiting device of the present invention can reduce the deterioration of communication quality.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of a narrow-band interference wave limiting device of the present invention.

FIG. 2 is a diagram illustrating frequency characteristics of signals before and after passing through the narrow-band interference wave limiting device of FIG. 1;

FIG. 3 is a diagram illustrating frequency characteristics of signals before and after passing through the narrow-band interference wave limiting device of FIG. 1;

FIG. 4 is a diagram illustrating frequency characteristics of signals before and after passing through the narrow-band interference wave limiting device of FIG. 1;

FIG. 5 is a block diagram showing another embodiment of the narrow-band interference wave limiting device of the present invention.

6 is a diagram illustrating frequency characteristics of a signal before and after passing through the narrow-band interference wave limiting device of FIG. 5;

FIG. 7 is a block diagram showing still another embodiment of the narrow band interference wave limiting device of the present invention.

FIG. 8 is a diagram showing a relationship between a spread signal and a pass band of each band pass filter in the narrow band interference wave limiting device of FIG. 7;

FIG. 9 is a block diagram showing a cancellation type narrow band interference wave limiting circuit used in the narrow band interference wave limiting device of the present invention.

FIG. 10 is a diagram illustrating frequency characteristics of signals in respective sections of the narrow-band interference wave limiting circuit of FIG. 9;

FIG. 11 is a block diagram showing one embodiment of the communication device of the present invention.

FIG. 12 is a block diagram showing a conventional narrow-band interference wave limiting device.

13 is a diagram illustrating frequency characteristics of signals before and after passing through the narrow-band interference wave limiting device of FIG. 12;

FIG. 14 is a diagram illustrating frequency characteristics of signals before and after passing through the narrow-band interference wave limiting device of FIG. 12;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 2 ... Input terminal 3 ... Variable amplification factor amplifier 5 ... Output terminal 10, 20, 30 ... Narrow band interference wave limitation device 11 ... Spread signal division means 12, 43 ... Narrow band interference wave limitation means 13, 21, 44 ... Spread signal Combining means 14, 31, 34, 36 ... signal distributor 15, 33, 38, 39, 40, 41 ... signal combiner 42 ... interference wave band selecting means 50 ... narrow band interference wave limiting circuit BPF1, BPF2, BPF3, BPF4 , BPF5,
BPF6, BPF7, BPF8, BPF9, BPF1
0, BPF11, BPF12, BPF13, BPF14
... Bandpass filters MSW1, MSW2, MSW3, MSW4, MSW5 ...
Magnetostatic wave filter SW1, SW2, SW3, SW4, SW5, SW6 ... switch

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Tetsu Nishimura 2-26-10 Tenjin, Nagaokakyo-shi, Kyoto Inside Murata Manufacturing Co., Ltd. (72) Inventor Hiroaki Tanaka 2-26-10 Tenjin, Nagaokakyo-shi, Kyoto Stock Company Murata Manufacturing F-term (reference) 5J006 JA31 KA08 KA11 KA12 KA21 LA01 LA06 PB02 5K020 AA00 DD03 EE01 EE05 EE16 EE18 HH13 KK01 KK07 LL01 MM00 5K022 EE02 EE35

Claims (7)

[Claims] 1. A spread signal dividing means for dividing an input spread signal into a plurality of sub-bands having different frequency bands, and a narrow-band interference wave included in the spread signal divided into the plurality of sub-bands. A narrow-band interference wave limiting means comprising a narrow-band interference wave limiting circuit using a plurality of magnetostatic wave filters for limiting the respective signals; Means for limiting narrow-band interference waves. 2. The spread signal synthesizing unit synthesizes a spread signal in which narrow-band interference waves are restricted for each of the plurality of small bands only for each of the plurality of small bands. Item 2. The narrow-band interference wave limiting device according to Item 1. 3. An interference for selecting a small band having the highest signal level by repeating a plurality of times of dividing an input spread signal into two frequency bands that do not overlap each other and selecting a higher signal level. Wave band selecting means, narrow band interference wave limiting means having a narrow band interference wave limiting circuit using a magnetostatic wave filter for limiting a narrow band interference wave included in the small band selected by the interference wave band selecting means, A narrow-band interfering wave, comprising: a spread signal synthesizing unit for synthesizing a spread signal of a narrow band in which the narrow-band interference wave is restricted to a spread signal of a frequency band excluded by the interference wave band selecting unit. Limiting device. 4. The spread signal synthesizing means restricts a spread signal of a small band in which the narrow band interference wave is restricted to the spread signal of the frequency band excluded by the spread signal selecting means to the small band. 4. The narrow-band interference wave limiting device according to claim 3, wherein the signals are combined. 5. The narrow-band interference wave limiting circuit comprises a magnetostatic wave filter for frequency-selectively limiting a signal of a certain level or more. Narrow band interference wave limiting device. 6. The narrow-band interference wave limiting circuit comprises: signal distribution means for distributing an input signal into two;
Level difference creating means using a magnetostatic wave filter for making the level difference between the narrow band interference wave and the spread signal included in the two signals different from each other, and two signals having different level differences between the narrow band interference wave and the spread signal, The narrow-band interference wave limiting device according to any one of claims 1 to 4, further comprising a signal combining unit that combines the levels of the narrow-band interference waves and inverts the phases of the narrow-band interference waves. 7. A communication device using the narrow-band interference wave limiting device according to claim 1.