JPH10107683A - Spread spectrum communication device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate narrow band interference waves whose level is higher than a spread signal by simultaneously sending a spread signal and a pilot signal which has a constant level ratio with the spread signal. SOLUTION: A signal which is inputted from a signal input terminal 2 is limited into a fixed level in a liter 6 and inputted to a signal synthesizer 9. On the other hand, a pilot signal which is outputted from a pilot signal generator 7 is limited into a fixed level in a limiter 8 and inputted to the synthesizer 9. In such cases, the pilot signal limited by the limiter 8 is set to have a fixed level ratio with the spread signal which is limited by the limiter 6. Thus, by setting the pilot and spread signals so that they may have a fixed level ratio, the level of a spread signal which has possibility to be buried in noise from the level of the pilot signal is calculated in receiving a signal, and a narrow band interference wave whose level is higher than a spread signal can be eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spread spectrum communication apparatus, and more particularly to a spread spectrum communication apparatus suitable for removing narrow band interference waves at the time of reception.

[0002]

2. Description of the Related Art FIG. 19 shows an example of a spread signal level detection circuit which is a part of a narrow band interference wave removing means in a conventional spread spectrum communication apparatus. In FIG. 19, the level detection circuit 200 includes three band-pass filters 201 and 20.
2, 203 and level comparison circuit 204, changeover switch 205, detector 206, input terminal 207, output terminal 20
8. The changeover switch 205 has a control terminal 205a. Three bandpass filters 201,
The input sides of 202 and 203 are combined into one and connected to the input terminal 207, and the output side is divided into two, respectively.
Each of the level comparison circuit 204 and the changeover switch 20
5 is connected. The output of the level comparison circuit 204 is connected to the control terminal 205a of the changeover switch 205, and the output of the changeover switch 205 is connected to the output terminal 208 via the detector 206.

FIG. 20 shows the relationship between the spectrum of a spread signal and three band-pass filters 201, 202 and 203. In FIG. 20, 200s denotes a spread signal, 201
w, 202w, and 203w indicate the pass bands of the three band-pass filters 201, 202, and 203, respectively. FIG.
, Three band-pass filters 201, 20
2, 203 pass bands 201w, 202w, 203w
Are set near the center of the frequency band of the spread signal so as not to overlap each other.

In FIG. 19, a spread signal received by a signal receiving means (not shown) is input from an input terminal 207 and divided into three, and the three band-pass filters 20 are used.
1, 202 and 203 are input. Since the spread signal is distributed almost uniformly in the frequency band, as shown in FIG. 20, each band-pass filter 201, 202, 203
The spread signal that has passed through is approximately at the same level. However, when a narrow band interfering wave is added to the spread signal, the output of the band pass filter that includes the frequency of the narrow band interfering wave in the pass band becomes higher than the output of the other band pass filters. Therefore, the three band-pass filters 201, 20
The outputs of the signals 2 and 203 are compared by a level comparison circuit 204, and a changeover switch 205 is controlled so that a signal in a pass band in which a signal with the lowest level is detected is passed. The changeover switch 205 has three bandpass filters 201, 202, 20 according to the control of the level comparison circuit 204.
The signal having the lowest level among the signals passing through No. 3 is passed as the level of the spread signal and input to the detector 206.
Detector 206 detects the level of the input signal and outputs it to output terminal 208. Thus, the level of the spread signal is detected, and based on the detected level, a narrow band interference wave having a higher level than the spread signal, which is included in the spread signal, is removed by a narrow band interference wave removal circuit (not shown).

In the example shown in FIG. 19, three bandpass filters are used. However, as the number of bandpass filters is increased and the passband is narrowed, the detection accuracy of the level of the spread signal becomes higher.

[0006]

However, in the above-described level detection circuit, a large number of band-pass filters are required to detect the level of the spread signal, and a circuit for comparing the levels is required. It was complicated.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems by simultaneously transmitting information for determining the level of a spread signal when transmitting a spread signal, and by using a simple device when receiving a spread signal. Provided is a spread spectrum communication apparatus capable of detecting a signal level and removing a narrow band interference wave having a higher level than a spread signal.

[0008]

To achieve the above object, a spread spectrum communication apparatus according to the present invention comprises a signal transmitting means for transmitting a spread signal and a pilot signal having a fixed level ratio with the spread signal. And a signal receiving means for receiving the spread signal, and a narrow-band interference wave removing means for removing a narrow-band interference wave included in the received spread signal.

Further, the spread spectrum communication apparatus of the present invention provides a spread spectrum signal and a frequency band of the spread signal simultaneously with the spread signal.
A signal transmitting means for multiplexing and transmitting a non-spread signal having a higher fixed level than the spread signal; a signal receiving means for receiving the spread signal; and a narrower for removing a narrow band interference wave included in the received spread signal. It is characterized by having at least band interference wave removing means.

A spread spectrum communication apparatus according to the present invention comprises: a signal transmitting means for transmitting a control signal having a fixed level ratio with the spread signal at the same time as the spread signal; and a signal receiving means for receiving the spread signal. , Characterized by having at least narrow band interference wave removing means for removing a narrow band interference wave included in the received spread signal.

Further, the spread spectrum communication apparatus according to the present invention is characterized in that the spread signal is a multiplex signal in which a plurality of spread signals spread by different spreading codes are superimposed on the same frequency band.

Also, the spread spectrum communication apparatus of the present invention comprises a signal transmitting means for transmitting a spread signal, and a pilot signal having a constant level ratio with the spread signal transmitted together with the spread signal at the same time as the spread signal. It is characterized by having at least signal receiving means for receiving, and narrow band interference wave removing means for obtaining the level of the spread signal from the level of the pilot signal and removing the narrow band interference wave having a higher level than the spread signal.

A spread spectrum communication apparatus according to the present invention further comprises a signal transmitting means for transmitting a spread signal, and a signal having a fixed ratio level higher than the spread signal by being multiplexed with the spread signal and simultaneously with the spread signal transmitted together with the spread signal. Signal receiving means for receiving a non-spread signal having a high level, and narrow-band interference wave removing means for obtaining a level of the spread signal in accordance with the level of the non-spread signal and removing a narrow-band interference wave having a higher level than the spread signal At least.

A spread spectrum communication apparatus according to the present invention comprises a signal transmitting means for transmitting a spread signal, and a control signal having a constant level ratio with the spread signal transmitted simultaneously with the spread signal. Signal receiving means for obtaining the level of the spread signal from the level of the control signal, and at least narrow band interference wave removing means for removing a narrow band interference wave having a higher level than the spread signal. I do.

Further, in the spread spectrum communication apparatus according to the present invention, the narrow band interference wave removing means is a magnetostatic wave filter which operates as a limiter for limiting a level on a frequency axis.

In the spread spectrum communication apparatus according to the present invention, the narrow band interference wave removing means includes a frequency / time conversion circuit for converting the spectrum of the spread signal into a time signal, and the frequency / time converted spread signal. And a time / frequency conversion circuit for returning the spread signal, which has been converted into a time signal and whose amplitude has been limited, to a spectrum.

[0017]

FIG. 1 shows an embodiment of a spread spectrum communication apparatus according to the present invention. In FIG. 1, the spread spectrum communication apparatus 1 includes a narrow band interference wave removing unit 13 and a mixer 1.
4, a despreader 15, a signal output terminal 16, and a signal transmitting means 17. The signal transmitting means 17 includes a signal input terminal 2, a signal spreader 3, a local signal source 4, a mixer 5,
It comprises a limiter 6, a pilot signal generator 7, a limiter 8, a signal combiner 9, an amplifier 10, an antenna duplexer 11, and an antenna 12. Among them, the antenna duplexer 11 and the antenna 12 also serve as the signal receiving means 18.

Here, the signal input terminal 2 is connected to the mixer 5 via the signal spreader 3, and the local signal source 4 is also connected to the mixer 5. The output of the mixer 5 is connected via a limiter 6 to a signal combiner 9. The pilot signal generator 7 is connected to a signal synthesizer 9 via a limiter 8. The output of the signal combiner 9 is connected to an antenna 12 via an amplifier 10 and an antenna duplexer 11. In addition, antenna duplexer 1
1 is connected to the mixer 14 via the narrow band interference wave removing means 13, and the local signal source 4 is also connected to the mixer 14.
The output of the mixer 14 is connected to a signal output terminal 16 via a despreader 15.

In the spread spectrum communication apparatus 1 configured as described above, the signal input from the signal input terminal 2 is spread in spectrum by the signal spreader 3, frequency-converted by the mixer 5, and brought to a fixed level by the limiter 6. The signal is restricted and input to the signal synthesizer 9. On the other hand, the pilot signal output from pilot signal generator 7 is limited to a certain level by limiter 8 and input to signal synthesizer 9. At this time, the pilot signal restricted by the limiter 8 is set to have a certain level ratio with the spread signal restricted by the limiter 6. The spread signal and the pilot signal input to the signal synthesizer 9 are synthesized by the signal synthesizer 9,
The signal is amplified by the amplifier 10 and radiated from the antenna 12 via the antenna sharing device 11. Further, the signal received by the antenna 12 is input to the narrow-band interference wave removing means 13 via the antenna duplexer 11, where the narrow-band interference wave is removed, frequency-converted by the mixer 14, and de-spread by the despreader 15. The signal is spread and output to the signal output terminal 16.

FIG. 2 shows an example of the spectrum of the signal synthesized by the signal synthesizer 9. In FIG. 2, the horizontal axis represents frequency,
The vertical axis represents the signal level. A is a spread signal, b
Represents a pilot signal. The pilot signal b has a frequency slightly lower than the frequency band of the spread signal a, and its level is
The fixed level ratio is set to 5 dB higher than the level of the spread signal a.

As described above, by setting the pilot signal and the spread signal so as to have a constant level ratio, the level of the spread signal that may be buried in noise is obtained from the level of the pilot signal at the time of signal reception. It is possible to remove a narrow band interference wave having a higher level than the spread signal.

In the example of FIG. 2, the frequency of the pilot signal is set lower than the frequency band of the spread signal, but this may be set higher than the frequency band of the spread signal, or the frequency band of the spread signal. You may set it inside. Although the number of pilot signals is one, a plurality of pilot signals may be used in consideration of the fact that the frequency of the pilot signal and the frequency of the narrowband interference wave may coincide. Also, as a constant level ratio, the level of the pilot signal is set to be 5 dB higher than the level of the spread signal. However, if the level of the spread signal can be obtained from the level of the pilot signal, the level ratio is not limited to 5 dB. If the frequency of the pilot signal is outside the frequency band of the spread signal, the level of the pilot signal may be the same as or lower than the level of the spread signal, such as 0 dB, -5 dB, or -10 dB.

FIG. 3 shows another embodiment of the spread spectrum communication apparatus according to the present invention. In FIG. 3, the spread spectrum communication apparatus 20 includes a narrow band interference wave removing unit 33, a mixer 34,
It comprises a despreader 35, a signal output terminal 36, and a signal transmitting means 37. The signal transmitting means 37 includes a signal input terminal 21;
It comprises a signal spreader 22, a local signal source 23, a mixer 24, a limiter 25, a non-spread signal input terminal 26, a mixer 27, a limiter 28, a signal combiner 29, an amplifier 30, an antenna duplexer 31, and an antenna 32. Among them, the antenna duplexer 31 and the antenna 32 also serve as the signal receiving means 38.

Here, the signal input terminal 21 is connected to the signal spreader 2.
2, and the output of the mixer 24 is connected to a signal synthesizer 29 via a limiter 25. On the other hand, the non-spread signal input terminal 26 is connected to the mixer 27,
The output of the mixer 27 is passed through a limiter 28 to the signal combiner 2.
9 is connected. The output of the local signal source 23 is connected to the mixer 24 and the mixer 27. Signal synthesizer 2
The output of 9 is connected to an antenna 32 via an amplifier 30 and a duplexer 31. The antenna duplexer 31 is connected to the mixer 34 via the narrow band interference wave removing means 33, and the local signal source 23 is also connected to the mixer 34. The output of the mixer 34 is supplied to a signal output terminal 3 via a despreader 35.
6 is connected.

In the spread spectrum communication apparatus 20 configured as described above, the signal input from the signal input terminal 21 is spread spectrum by the signal spreader 22 and
The signal is frequency-converted at 4 and is limited to a certain level by a limiter 25 and input to a signal synthesizer 29. On the other hand, the signal input from the non-spread signal input terminal 26 is frequency-converted by the mixer 27, limited to a certain level by the limiter 28, and input to the signal synthesizer 29. At this time, the limiter 28
Is set to be higher than the level of the spread signal limited by the limiter 25 by a fixed ratio. The spread signal and the non-spread signal input to the signal synthesizer 29 are synthesized by the signal synthesizer 29 and
Is amplified by the antenna 3 via the antenna duplexer 31.
Radiated from 2. Further, the signal received by the antenna 32 is input to the narrow-band interference wave removing means 33 via the antenna duplexer 31 to remove the narrow-band interference wave.
The signal is frequency-converted at 4 and despread by a despreader 35 and output to a signal output terminal 36.

FIG. 4 shows an example of the spectrum of the signal synthesized by the signal synthesizer 29. In FIG. 4, the horizontal axis represents frequency, and the vertical axis represents signal level. C represents a spread signal, and d represents a non-spread signal. The frequency band of the non-spread signal d overlaps the frequency band of the spread signal c, and its level is set to be 5 dB higher than the level of the spread signal c as a constant level ratio.

As described above, by setting the level of the non-spread signal higher than the level of the spread signal by a fixed ratio, the level of the spread signal which may be buried in noise from the level of the non-spread signal at the time of signal reception is obtained. It is possible to remove a narrow band interference wave having a higher level than the spread signal.

Although the number of non-spread signals is four in the example of FIG. 4, the number of non-spread signals can be freely set within a range that does not affect the quality of the spread signal. Although the level of the non-spread signal is set to be 5 dB higher than the level of the spread signal, the level ratio is limited to 5 dB if the level is higher than the spread signal and the level of the spread signal can be obtained from the level of the non-spread signal. Instead, it may be 10 dB or 20 dB.

FIG. 5 shows still another embodiment of the spread spectrum communication apparatus of the present invention. 5, the spread spectrum communication apparatus 40 includes a narrow band interference wave removing unit 52, a mixer 53, a despreader 54, a signal output terminal 55, and a signal transmitting unit 56. The signal transmitting means 56 includes a signal input terminal 41, a signal spreader 42, a local signal source 43, and a mixer 4.
4, a limiter 45, a control signal generator 46 for controlling communication, a limiter 47, a signal combiner 48, and an amplifier 4.
9, an antenna duplexer 50 and an antenna 51.
Among them, the antenna duplexer 50 and the antenna 51 also serve as the signal receiving means 57.

Here, the signal input terminal 41 is connected to the signal spreader 4.
2 and a local signal source 43
Is also connected to the mixer 44. The output of the mixer 44 is connected to a signal combiner 48 via a limiter 45. The control signal generator 46 is connected to a signal synthesizer 48 via a limiter 47. The output of the signal combiner 48 is connected to an antenna 51 via an amplifier 49 and an antenna duplexer 50. Further, the antenna duplexer 50 is connected to the mixer 53 via the narrow band interference wave removing means 52, and the local signal source 43 is also connected to the mixer 53. The output of the mixer 53 is a despreader 5
4 to a signal output terminal 55.

In the thus configured spread spectrum communication apparatus 40, the signal input from the signal input terminal 41 is spread spectrum by the signal spreader 42 and
The signal is frequency-converted at 4 and is limited to a certain level at a limiter 45 and input to a signal synthesizer 48. On the other hand, the control signal output from the control signal generator 46 is the limiter 4
At 7, the signal is limited to a certain level and input to the signal synthesizer 48. At this time, the control signal restricted by the limiter 47 is set to have a certain level ratio with the spread signal restricted by the limiter 45. The two signals, the spread signal and the control signal, input to the signal combiner 48 are combined by the signal combiner 48, amplified by the amplifier 49, and radiated from the antenna 51 via the antenna duplexer 50. The signal received by the antenna 51 is transmitted to the antenna duplexer 5.
0, the signal is input to the narrow band interference wave removing means 52 to remove the narrow band interference wave, and the frequency is converted by the mixer 53.
The signal is despread by the despreader 54 and output to the signal output terminal 55.

FIG. 6 shows an example of the spectrum of the signal synthesized by the signal synthesizer 48. In FIG. 6, the horizontal axis represents frequency, and the vertical axis represents signal level. E is a spread signal,
f represents a control signal. The control signal f has a frequency slightly higher than the frequency band of the spread signal e, and its level is set as a fixed level ratio 5 dB higher than the level of the spread signal e.

As described above, by setting the control signal and the spread signal so as to have a constant level ratio, the level of the spread signal which may be buried in noise from the level of the control signal when receiving the signal is reduced. As a result, a narrow-band interference wave having a higher level than the spread signal can be removed.

Although the frequency of the control signal is set higher than the frequency band of the spread signal in the example of FIG. 6, it may be set lower than the frequency band of the spread signal or the frequency band of the spread signal. May be set in. Further, the level of the control signal is set to be 5 dB higher than the level of the spread signal. However, if the level of the spread signal can be obtained from the level of the control signal, the level ratio is not limited to 5 dB but may be 10 dB or 20 dB. If the frequency of the control signal is outside the frequency band of the spread signal, the level of the control signal may be the same as or lower than the level of the spread signal, such as 0 dB, -5 dB, or -10 dB.

FIG. 7 shows still another embodiment of the spread spectrum communication apparatus of the present invention. 7, the spread spectrum communication apparatus 60 includes a narrow band interference wave removing unit 73, a mixer 74, a despreader 75, a signal output terminal 76, and a signal transmitting unit 77. The signal transmitting means 77 includes signal input terminals 61a, 61b,... 61n, signal spreaders 62a, 62
.. 62n, local signal source 63, mixer 64
64n, limiters 65a, 65b,
.., 65n, a signal combiner 66, a pilot signal generator 67, a limiter 68, a signal combiner 69, an amplifier 70, an antenna duplexer 71, and an antenna 72. Among them, the antenna duplexer 71 and the antenna 72 also serve as the signal receiving means 78.

Here, the signal input terminals 61a, 61b,.
.. 61n are signal spreaders 62a, 62b,.
64n are connected to the mixers 64a, 64b,... 64n, respectively.
b,... 64n. Mixer 64
The outputs of a, 64b,... 64n are limiters 6 respectively.
65n are connected to the signal combiner 66 via 5a, 65b,... 65n. The output of the signal combiner 66 is connected to the signal combiner 69. On the other hand, pilot signal generator 67 is connected to signal synthesizer 69 via limiter 68. The output of the signal combiner 69 is connected to an antenna 72 via an amplifier 70 and an antenna duplexer 71. In addition, antenna duplexer 7
1 is connected to the mixer 74 via the narrow band interference wave removing means 73, and the local signal source 63 is also connected to the mixer 74. The output of the mixer 74 is connected to a signal output terminal 76 via a despreader 75.

In the spread spectrum communication apparatus 60 thus configured, the signal input terminals 61a, 61b,.
The signals input from 61n are spreaders 62
a, 62b,... 62n, frequency-converted by mixers 64a, 64b,... 64n, limited to a certain level by limiters 65a, 65b,. And the signal synthesizer 69
Is input to On the other hand, the signal output from pilot signal generator 67 is limited to a certain level by limiter 68 and input to signal combiner 69. At this time, limiter 6
The pilot signal limited by 8 is set to have a fixed level ratio with the combined spread signal output from the signal combiner 66. The spread signal and pilot signal input to the signal combiner 69 are combined by the signal combiner 69, amplified by the amplifier 70, and radiated from the antenna 72 via the antenna duplexer 71. Also, the antenna 72
The signal received at (1) is input to the narrow band interference wave removing means 73 via the duplexer 71 to remove the narrow band interference wave, frequency-converted by the mixer 74, and despread by the despreader 75. Output to the output terminal 76.

FIG. 8 shows an example of the spectrum of the signal synthesized by the signal synthesizer 69. In FIG. 8, the horizontal axis represents frequency, and the vertical axis represents signal level. G represents a signal obtained by combining a plurality of spread signals, and h represents a pilot signal.
The pilot signal h has a frequency slightly lower than the frequency band of the synthesized spread signal g, and its level is set to be 5 dB higher than the level of the synthesized spread signal g as a fixed level ratio.

As described above, by setting the pilot signal and the spread signal so as to have a constant level ratio, the level of the spread signal that may be buried in noise is obtained from the level of the pilot signal at the time of signal reception. It is possible to remove a narrow band interference wave having a higher level than the spread signal.

Although the frequency of the pilot signal is set lower than the frequency band of the spread signal in the example of FIG. 8, it can be set higher than the frequency band of the spread signal or the frequency band of the spread signal. You may set it inside. Although the number of pilot signals is one, a plurality of pilot signals may be used in consideration of the fact that the frequency of the pilot signal and the frequency of the narrowband interference wave may coincide. Also, the level of the pilot signal is set to be 5 dB higher than the level of the spread signal. However, if the level of the spread signal can be obtained from the level of the pilot signal, the level ratio is not limited to 5 dB, and may be 10 dB or 20 dB. If the frequency of the pilot signal is outside the frequency band of the spread signal, the level of the pilot signal is equal to or lower than the level of the spread signal, ie, 0 dB, -5 dB, or -1.
It may be 0 dB or the like.

In the embodiments shown in FIGS. 1, 3, 5, and 7, the limiters are used for setting the levels of the spread signal, the pilot signal, the non-spread signal, and the control signal. This may use another device such as an automatic gain control amplifier as long as the level can be set to a target value.

FIG. 9 shows still another embodiment of the spread spectrum communication apparatus of the present invention. 9, a spread spectrum communication apparatus 80 includes an antenna 81, an antenna duplexer 82,
It comprises narrow band interference wave removing means 83, local signal source 84, mixer 85, despreader 86, signal output terminal 87, signal transmission circuit 88, and signal input terminal 89. The narrow band interference wave removing means 83 includes a distributor 90, a pilot signal detection circuit 91, a level detection circuit 92, and a narrow band interference wave removal circuit 93.
It consists of. Among them, the antenna 81 and the antenna duplexer 82 constitute a signal receiving means 94. Further, the antenna 81 and the antenna duplexer 82 constitute a signal transmission means 95 by adding a signal transmission circuit 88 and a signal input terminal 89.

Here, the antenna 81 is the antenna duplexer 8
2 and a distributor 90 are connected to both a pilot signal detection circuit 91 and a narrow band interference wave removal circuit 93. The pilot signal detection circuit 91 is connected to a narrow band interference wave removal circuit 93 via a level detection circuit 92. The narrow band interference wave removing circuit 93 is connected to the mixer 85. On the other hand, a local signal source 84 is also connected to the mixer 85. Mixer 85 is connected to signal output terminal 87 via despreader 86. The duplexer 82 is connected to a signal input terminal 89 via a signal transmission circuit 88.

In the spread spectrum communication apparatus 80 configured as above, the signal input from the signal input terminal 89 is radiated from the antenna 81 via the signal transmission circuit 88 and the antenna duplexer 82. The signal received by the antenna 81 is divided into two signals by a distributor 90 via an antenna duplexer 82, and one of the signals is divided into a pilot signal detection circuit 91
The other is input to the narrow band interference wave removing circuit 93. The pilot signal detection circuit 91 detects a pilot signal from the received signals. The pilot signal is input to a level detection circuit 92, where the level of the spread signal is obtained from a predetermined level ratio between the spread signal and the pilot signal, and the information is input to a narrow band interference wave removal circuit 93. . In accordance with the information from the level detection circuit 92, the narrow band interference wave removing circuit 93 removes a narrow band interference wave included in the spread signal and having a higher level than the spread signal. The signal from which the narrow-band interference wave has been removed is frequency-converted by the mixer 85, despread by the despreader 86, and output from the signal output terminal 87.

FIG. 10 shows a state in which narrow-band interference waves are removed in the spread spectrum communication apparatus of FIG. 10A shows the spectrum of the signal received by the antenna 81, FIG. 10B shows the spectrum of the signal output from the narrow-band interference wave removing circuit 93, and FIG. 10C shows the spectrum of the signal output from the despreader 86. 2 shows the spectrum of the signal. Here, the horizontal axis represents frequency, and the vertical axis represents signal level.

In FIG. 10A, i1 is a spread signal, j1 is a pilot signal, and k1 is a narrow band interference wave. The level of pilot signal j1 is 5 dB higher than the level of spread signal i1, which is predetermined as a fixed level ratio and set at the time of transmission. The pilot signal detection circuit 91 outputs the pilot signal j
1 and the level of the spread signal i1 is determined based on a predetermined level ratio between the pilot signal j1 and the spread signal i1, and based on this level, the narrow-band interference wave removing circuit 93 determines the level of the narrow-band interference wave k1. Limit the level on the frequency axis. FIG. 10B shows a state in which the amplitude of the narrow band interference wave is limited. The level of the narrow band interference wave k2 is limited to the same level as the spread signal i2. When this signal is despread, as shown in FIG. 10 (c), the level of the narrow band interference wave k3 decreases, and the despread signal i3 has a sufficiently large level difference with respect to the narrow band interference wave k3. it can.

As described above, by receiving the pilot signal having a fixed level ratio with the spread signal simultaneously with the spread signal, the level of the spread signal is obtained, and a narrow band interference wave having a higher level than the spread signal is removed. it can.

In the example of FIG. 10, the level of the pilot signal is set higher than the spread signal by 5 dB, but the level ratio is limited to 5 dB as long as the level of the spread signal can be detected from the level of the pilot signal. not,
If the frequency of the pilot signal is outside the frequency band of the spread signal, the level of the pilot signal may be equal to or lower than the level of the spread signal.
It may be dB, -5 dB, -10 dB, or the like.

FIG. 11 shows still another embodiment of the spread spectrum communication apparatus of the present invention. In FIG. 11, a spread spectrum communication apparatus 100 includes an antenna 101, an antenna duplexer 102, a narrow band interference wave removing unit 103, a local signal source 104, a mixer 105, a despreader 106, a signal output terminal 107, a signal transmission circuit 108, It consists of an input terminal 109. The narrow-band interference wave removing means 103 includes the distributor 1
10, non-spread signal detection circuit 111, level detection circuit 11
2. It is composed of a narrow band interference wave removal circuit 113. The antenna 101 and the antenna duplexer 102 constitute a signal receiving unit 114. Further, the antenna 101 and the antenna duplexer 102 constitute a signal transmission unit 115 by adding a signal transmission circuit 108 and a signal input terminal 109.

Here, the antenna 101 is connected to the non-spreading signal detecting circuit 11 via the antenna duplexer 102 and the distributor 110.
1 and the narrow band interference wave removing circuit 113.
The non-spread signal detection circuit 111 is connected to a narrow band interference wave removal circuit 113 via a level detection circuit 112. The narrow band interference wave removing circuit 113 is connected to the mixer 105. On the other hand, the local signal source 104 is also connected to the mixer 105. Mixer 105 is connected to signal output terminal 107 via despreader 106. And the antenna duplexer 102
Is connected to a signal input terminal 109 via a signal transmission circuit 108.

In the spread spectrum communication apparatus 100 configured as described above, the signal input from the signal input terminal 109 is radiated from the antenna 101 via the signal transmission circuit 108 and the duplexer 102. A signal received by the antenna 101 is divided into two signals by the distributor 110 via the antenna duplexer 102, one of which is provided to the non-spreading signal detection circuit 111, and the other is provided to the narrow band interference wave removal circuit 113.
Is input to The non-spread signal detection circuit 111 detects a non-spread signal from the received signals. The non-spread signal is input to the level detection circuit 112, where the level of the spread signal is obtained from a predetermined level ratio between the spread signal and the non-spread signal, and the information is input to the narrow band interference wave removal circuit 113. Is done. Narrow band interference wave removal circuit 113
Then, according to the information from the level detection circuit 112,
A narrow band interference wave having a higher level than the spread signal included in the spread signal is removed. The signal from which the narrowband interference wave has been removed is frequency-converted by mixer 105, despread by despreader 106, and output from signal output terminal 107.

FIG. 12 shows a state of removing a narrow band interference wave in the spread spectrum communication apparatus of FIG. 12, (a) shows the spectrum of the signal received by the antenna 101, (b) shows the spectrum of the signal output from the narrow-band interference wave removing circuit 113, and (c) shows the despreader 106.
2 shows the spectrum of the signal output from. Here, the horizontal axis represents frequency, and the vertical axis represents signal level.

In FIG. 12A, m1 denotes a spread signal, n1 denotes a non-spread signal, and o1 denotes a narrow band interference wave.
The level of the non-spread signal n1 is 5 times higher than the level of the spread signal m1.
Although the dB is higher, this is predetermined as a constant level ratio and set at the time of transmission. The non-spreading signal detecting circuit 111 obtains the level of the spreading signal m1 based on the level of the non-spreading signal n1 and a predetermined level ratio between the non-spreading signal n1 and the spreading signal m1.
Based on this level, the narrow band interference wave removing circuit 113 limits the amplitude of the narrow band interference wave o1. FIG. 12B shows a state in which the amplitude of the narrow band interference wave is limited. The levels of the narrow band interference wave o2 and the non-spread signal n2 are limited to the same level as the spread signal m2. When this signal is despread, as shown in FIG. 12 (c), the levels of the narrow-band interference wave n3 and the non-spread signal o3 decrease, and the despread signal m3
Can secure a sufficiently large level difference with respect to the narrow band interference wave n3 and the non-spread signal o3.

As described above, by receiving a non-spread signal having a certain level ratio with the spread signal simultaneously with the spread signal, the level of the spread signal is obtained, and a narrow band interference wave having a higher level than the spread signal is removed. Can be.

In the example shown in FIG. 12, the level of the non-spread signal is set to be 5 dB higher than that of the spread signal. However, the level is higher than that of the spread signal, and the level of the spread signal can be detected from the level of the non-spread signal. For example, the level ratio is not limited to 5 dB, but may be 10 dB or 20 dB.

FIG. 13 shows still another embodiment of the spread spectrum communication apparatus of the present invention. 13, a spread spectrum communication apparatus 120 includes an antenna 121, an antenna duplexer 122, a narrow band interference wave removing unit 123, a local signal source 124, a mixer 125, a despreader 126, a signal output terminal 127, a signal transmission circuit 128, a signal An input terminal 129 is provided. The narrow-band interference wave removing means 123 includes the distributor 1
30, control signal detection circuit 131, level detection circuit 13
2. It is composed of a narrow band interference wave removing circuit 133. Among them, the antenna 121 and the antenna duplexer 122 constitute a signal receiving unit 134. In addition, the antenna 121 and the antenna duplexer 122 constitute a signal transmission unit 135 by adding a signal transmission circuit 128 and a signal input terminal 129.

Here, the antenna 121 is connected to the control signal detecting circuit 13 through the antenna duplexer 122 and the distributor 130.
1 and the narrow-band interference wave removing circuit 133.
The control signal detection circuit 131 is connected to the narrow band interference wave removal circuit 133 via the level detection circuit 132. The narrow band interference wave removing circuit 133 is connected to the mixer 125. On the other hand, a local signal source 124 is also connected to the mixer 125. Mixer 125 is connected to signal output terminal 127 via despreader 126. And the antenna duplexer 122
Is connected to the signal input terminal 129 via the signal transmission circuit 128.

In the spread spectrum communication apparatus 120 thus configured, the signal input from the signal input terminal 129 is radiated from the antenna 121 via the signal transmission circuit 128 and the antenna duplexer 122. The signal received by the antenna 121 is divided into two signals by the distributor 130 via the antenna duplexer 122, one of which is input to the control signal detection circuit 131, and the other is input to the narrow band interference wave removal circuit 133. . The control signal detection circuit 131 detects a control signal from the received signals. The control signal is input to the level detection circuit 132, where the level of the spread signal is obtained from a predetermined level ratio between the spread signal and the control signal, and the information is input to the narrow band interference wave removal circuit 133. Is done. The narrow-band interference wave removing circuit 133 removes a narrow-band interference wave included in the spread signal and having a higher level than the spread signal, according to the information from the level detection circuit 132. The signal from which the narrow-band interference wave has been removed is frequency-converted by mixer 125, despread by despreader 126, and output from signal output terminal 127.

FIG. 14 shows a state of removing a narrow band interference wave in the spread spectrum communication apparatus of FIG. 14, (a) shows the spectrum of the signal received by the antenna 121, (b) shows the spectrum of the signal output from the narrow band interference wave canceling circuit 133, and (c) shows the despreader 126.
2 shows the spectrum of the signal output from. Here, the horizontal axis represents frequency, and the vertical axis represents signal level.

In FIG. 14A, p1 is a spread signal, q1 is a control signal, and r1 is a narrow band interference wave.
The level of the control signal q1 is 5 times higher than the level of the spread signal p1.
Although the dB is higher, this level ratio is predetermined and set at the time of transmission. The control signal detection circuit 131 obtains the level of the spread signal q1 based on the level of the control signal q1 and a predetermined level ratio between the control signal q1 and the spread signal p1, and the narrow band is determined based on this level. The interference wave removing circuit 133 limits the amplitude of the narrow band interference wave r1. FIG. 14B shows a state in which the amplitude of the narrow-band interference wave r2 is limited. The level of the narrow band interference wave r2 is limited to the same level as the spread signal p2. When this signal is despread, as shown in FIG. 14 (c), the level of the narrow band interference wave r3 decreases, and the despread signal p
3 can ensure a sufficiently large level difference with respect to the narrow band interference wave r3.

As described above, by receiving the control signal having a fixed level ratio with the spread signal simultaneously with the spread signal, the level of the spread signal is obtained, and a narrow band interference wave having a higher level than the spread signal is removed. Can be.

In the example of FIG. 14, the level of the control signal is set higher than the spread signal by 5 dB. However, if the level of the spread signal can be detected from the level of the control signal, the level ratio becomes 5 dB. Not limited, 10dB
If the frequency of the control signal is outside the frequency band of the spread signal, the level of the control signal is the same as or lower than the level of the spread signal, ie, 0 dB or -5 dB.
It may be -10 dB or the like.

FIG. 15 shows still another embodiment of the spread spectrum communication apparatus of the present invention. FIG. 15 shows an example of a configuration of a narrow band interference wave removing circuit in the narrow band interference wave removing means. FIG. 16 shows a state of removing the narrow-band interference wave in the narrow-band interference wave removal circuit shown in FIG.

In FIG. 15, a narrow band interference wave canceling circuit 1 is shown.
40 is a signal input terminal 141, a variable amplification factor amplifier 142,
It comprises a magnetostatic wave filter 143, a level setting circuit 144, a level signal input terminal 145, and a signal output terminal 146. The variable gain amplifier 142 has a control terminal 142a. The signal input terminal 141 is connected to the magnetostatic wave filter 143 via the amplification factor variable amplifier 142, and the output is connected to the signal output terminal 146. On the other hand, the level signal input terminal 145 is connected to the control terminal 142a of the amplification factor variable amplifier via the level setting circuit 144.

The spread signal input from the signal input terminal 141 is input to the variable gain amplifier 142. As shown in FIG. 16A, the signal input to the variable gain amplifier 142 is in a state where the narrow band interference wave t1 is included in the spread signal s1. The level of the spread signal s1 does not match the saturation level u of the magnetostatic wave filter 142. On the other hand, the level setting circuit 144 controls the control terminal 142 a of the variable gain amplifier 142 so that the level of the spread signal s 1 approaches the saturation level u of the magnetostatic wave filter 143 in accordance with the signal input from the level signal input terminal 145. Send a signal. The amplification factor variable amplifier 142 amplifies the level of the spread signal s1 to the saturation level u of the magnetostatic wave filter 143,
Input to the magnetostatic wave filter 143. Magnetostatic wave filter 14
3 is amplified so that the level of the spread signal s2 approaches the saturation level u of the magnetostatic wave filter 143, as shown in FIG. The magnetostatic wave filter 143 has a limiter characteristic on its frequency axis,
A signal having a level higher than the saturation level is limited and output to the signal output terminal 146. The output of the magnetostatic wave filter 143 is
As shown in FIG. 16C, a portion of the narrow band interference wave t3 higher than the level of the spread signal s3 is restricted. As described above, by using the magnetostatic wave filter to remove the narrow-band interference wave, the narrow-band interference wave can be reliably removed over a wide band as compared with the method using the band-stop filter.

FIG. 17 shows still another embodiment of the spread spectrum communication apparatus of the present invention. This case is also an example of the configuration of the narrow band interference wave removing circuit in the narrow band interference wave removing means. FIG. 18 shows a state of removing a narrow-band interference wave in the narrow-band interference wave removal circuit shown in FIG.

In FIG. 17, a narrow-band interference wave removing circuit 1 is shown.
50 is a signal input terminal 151, a frequency / time conversion circuit 1
52, level signal input terminal 153, level setting circuit 15
4. Amplitude limiting circuit 155, time / frequency conversion circuit 15
6, the signal output terminal 157. Amplitude limiting circuit 1
55 has a control terminal 155a. Signal input terminal 151
Is the amplitude limiting circuit 1 via the frequency / time converting circuit 152
53. The level signal input terminal 153 is connected to a control terminal 155a of the amplitude limiting circuit 155 via the level setting circuit 154. The output of the amplitude limiting circuit 155 is connected to the signal output terminal 157 via the time / frequency conversion circuit 156.

FIG. 18A shows the spectrum of the signal input from the signal input terminal 151. The spread signal v1 includes the narrow band interference wave w1. This signal is
The signal is subjected to frequency / time conversion by the time conversion circuit 152, becomes a signal whose amplitude changes on the time axis, and is input to the amplitude limiting circuit 155. The waveform of this signal is shown in FIG. FIG.
In (b), v2 is a spread signal and w2 is a narrow band interference wave. Also, x is the amplitude limit level of the amplitude limit circuit 155. On the other hand, a control signal is sent to the control terminal 155a of the amplitude limiting circuit 155 so as to limit the amplitude of the narrow band interference wave w2 according to the signal input from the level signal input terminal 153. The amplitude limiting circuit 155 limits the amplitude of the narrow band interference wave w2 included in the spread signal v2 to a limit level x set to be the same as the amplitude of the spread signal v2, and outputs the result. The state of this signal is shown in FIG. The amplitude of the narrow band interference wave w3 is limited to the same level as the spread signal v3. The output of the amplitude limiting circuit 155 is time / frequency converted by the time / frequency conversion circuit 156 and output to the signal output terminal 157. FIG. 18D shows the spectrum of the time-frequency converted signal. The narrow band interference wave w4 has dropped to the same level as the level of the spread signal v4. Thus, by converting the frequency and time of the signal,
With a simple amplitude limiting circuit, narrow-band interference can be reliably removed over a wide band.

[0069]

According to the spread spectrum communication apparatus of the present invention, at the same time as a spread signal, a pilot signal, a non-spread signal or a control signal having a fixed level ratio with respect to the spread signal is transmitted in the vicinity or at the same frequency band. it can. This makes it possible to estimate the level of the spread signal from the level of the pilot signal, non-spread signal, or control signal when the spread signal is received.

Further, a pilot signal, a non-spread signal, or a control signal is received simultaneously with the spread signal, and the level of the pilot signal, the non-spread signal, or the control signal is detected by a relatively simple circuit. The level of the spread signal can be estimated from the level ratio known in advance, which makes it possible to remove narrowband interference waves having a higher level than the spread signal.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a spread spectrum communication apparatus according to an embodiment of the present invention.

FIG. 2 is a block diagram of the spread spectrum communication apparatus shown in FIG.
FIG. 3 is a diagram illustrating a spectrum of a signal synthesized by a signal synthesizer.

FIG. 3 is a block diagram showing a configuration of a spread spectrum communication apparatus according to another embodiment of the present invention.

FIG. 4 is a block diagram of the spread spectrum communication apparatus shown in FIG.
FIG. 3 is a diagram illustrating a spectrum of a signal synthesized by a signal synthesizer.

FIG. 5 is a block diagram showing a configuration of a spread spectrum communication apparatus according to yet another embodiment of the present invention.

FIG. 6 is a block diagram of the spread spectrum communication apparatus shown in FIG.
FIG. 3 is a diagram illustrating a spectrum of a signal synthesized by a signal synthesizer.

FIG. 7 is a block diagram showing a configuration of a spread spectrum communication apparatus according to yet another embodiment of the present invention.

8 is a diagram illustrating the spread spectrum communication apparatus shown in FIG.
FIG. 3 is a diagram illustrating a spectrum of a signal synthesized by a signal synthesizer.

FIG. 9 is a block diagram showing a configuration of a spread spectrum communication apparatus according to yet another embodiment of the present invention.

10 is a diagram showing a state of removing a narrow band interference wave of a received signal in the spread spectrum communication apparatus shown in FIG. 9;
(A) shows the spectrum of the signal received by the antenna,
(B) shows the spectrum of the signal output from the narrow-band interference wave removing circuit, and (c) shows the spectrum of the signal output from the despreader.

FIG. 11 is a block diagram showing a configuration of a spread spectrum communication apparatus according to yet another embodiment of the present invention.

12 is a diagram showing a state of removing a narrow band interference wave of a received signal in the spread spectrum communication apparatus shown in FIG. 11,
(A) shows the spectrum of the signal received by the antenna,
(B) shows the spectrum of the signal output from the narrow-band interference wave removing circuit, and (c) shows the spectrum of the signal output from the despreader.

FIG. 13 is a block diagram showing a configuration of a spread spectrum communication apparatus according to yet another embodiment of the present invention.

14 is a diagram showing a state of removing a narrow band interference wave of a received signal in the spread spectrum communication apparatus shown in FIG. 13,
(A) shows the spectrum of the signal received by the antenna,
(B) shows the spectrum of the signal output from the narrow-band interference wave removing circuit, and (c) shows the spectrum of the signal output from the despreader.

FIG. 15 is a block diagram showing a configuration of a spread spectrum communication apparatus according to still another embodiment of the present invention.

16A and 16B are diagrams showing a state of removing a narrow band interference wave in the spread spectrum communication apparatus shown in FIG. 15, wherein FIG. 16A shows a spectrum of a signal input to a variable gain amplifier, and FIG.
Represents the spectrum of the signal input to the magnetostatic wave filter,
(C) shows the spectrum of the signal output from the magnetostatic wave filter.

FIG. 17 is a block diagram showing a configuration of a spread spectrum communication apparatus according to yet another embodiment of the present invention.

18A and 18B are diagrams showing a state of removing a narrow band interference wave in the spread spectrum communication apparatus shown in FIG. 17, wherein FIG. 18A shows a spectrum of a signal input from a signal input terminal, and FIG. The waveform of the signal output from the circuit is
(C) shows the waveform of the signal output from the amplitude limiting circuit,
(D) shows the spectrum of the signal output from the time / frequency conversion circuit.

FIG. 19 is a block diagram showing a configuration of a circuit for detecting a level of a spread signal in a conventional spread spectrum communication apparatus.

20 is a diagram illustrating a relationship between a spread signal and a band-pass filter in the spread spectrum communication apparatus illustrated in FIG. 19;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Spread spectrum communication apparatus 2 ... Signal input terminal 3 ... Signal spreader 4 ... Local signal source 5, 14 ... Mixer 6 ... Limiter 7 ... Pilot signal generator 8 ... Limiter 9 ... Signal combiner 10 ... Amplifier 11 ... Common antenna Device 12 Antenna 13 Narrow band interference wave removing means 15 Despreader 16 Signal output terminal 17 Signal transmitting means 18 Signal receiving means

Claims (9)

[Claims] 1. A signal transmitting means for transmitting a pilot signal having a certain level ratio with the spread signal simultaneously with the spread signal, a signal receiving means for receiving the spread signal, and a narrow signal included in the received spread signal. A spread spectrum communication apparatus comprising at least narrow band interference wave removing means for removing a band interference wave. 2. A signal transmitting means for multiplexing a spread signal and a non-spread signal having a higher level than the spread signal in a frequency band of the spread signal and transmitting the multiplexed signal, and a signal receiving means for receiving the spread signal And a narrow-band interference wave removing means for removing a narrow-band interference wave included in the received spread signal. 3. A signal transmitting means for transmitting a control signal having a certain level ratio with the spread signal at the same time as the spread signal; a signal receiving means for receiving the spread signal; and a signal included in the received spread signal. A spread spectrum communication apparatus comprising at least narrow band interference wave removing means for removing narrow band interference waves. 4. The spectrum according to claim 1, wherein said spread signal is a multiplexed signal in which a plurality of spread signals spread by different spreading codes are superimposed on the same frequency band. Spreading communication device. 5. A signal transmitting means for transmitting a spread signal; a signal receiving means for receiving, simultaneously with the spread signal, a pilot signal having a constant level ratio with the spread signal transmitted together with the spread signal; A spread spectrum communication apparatus comprising at least narrow band interference wave removing means for obtaining a level of a spread signal from a signal level and removing a narrow band interference wave having a higher level than the spread signal. 6. A signal transmitting means for transmitting a spread signal, and a signal for receiving a non-spread signal multiplexed with the spread signal and the spread signal transmitted together with the spread signal and having a higher fixed level than the spread signal. Receiving means for obtaining a level of the spread signal according to the level of the non-spread signal, and narrow-band interference wave removing means for removing a narrow-band interference wave having a higher level than the spread signal; Spreading communication device. 7. A signal transmitting means for transmitting a spread signal; a signal receiving means for receiving, at the same time as the spread signal, a control signal having a constant level ratio with the spread signal transmitted together with the spread signal; A spread spectrum communication apparatus comprising at least narrow band interference wave removing means for determining the level of a spread signal from a level of a control signal and removing a narrow band interference wave having a higher level than the spread signal. 8. The spread spectrum according to claim 5, wherein said narrow band interference wave removing means is a magnetostatic wave filter which operates as a limiter for limiting a level on a frequency axis. Communication device. 9. The narrow-band interfering wave removing means, comprising: a frequency-to-time conversion circuit for converting a spectrum of the spread signal into a time signal; and limiting an amplitude of the frequency-time converted spread signal on a time axis. 8. The spread spectrum communication apparatus according to claim 5, further comprising an amplitude limiting circuit, and a time / frequency conversion circuit for returning the spread signal, which has been converted to a time signal and the amplitude of which is limited, to a spectrum. .