JP2000078039A - Receiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically switch the band of a band pass filter in accordance with the reception situation of a reception signal. SOLUTION: A reception signal inputted from an input terminal 1 is amplified in a low noise amplifier 2, is mixed with a signal from a local oscillator 4 by MIX 3 and is distributed to a filter switch circuit 19 and an adjacent channel signal detection circuit 20 by a distributor 5. The reception signals supplied to the adjacent channel signal detection circuit 20 are supplied to upper/lower adjacent channel IF band pass filters 11 and 12 through the distributor 10, are level-detected and compared with a setting value in first/second comparators 15 and 16. When the signal level is not less than the setting value, a control signal is supplied to an OR element 18 and the switching of wide band/narrow band IF band pass filters 6 and 7 is instructed to the switch 8 of the filter switch circuit 19.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a receiving apparatus, a receiving method, and a recording medium. The present invention relates to a receiving apparatus, a receiving method, and a recording medium that switch and supply a signal to one of a wideband and a narrowband IF bandpass filter.

[0002]

2. Description of the Related Art FIG. 2 shows a conventional FPU (Field Pickup Uni) used for television signal transmission.
t) is a block diagram illustrating a configuration of an example of a receiving device. The low noise amplifier 2 amplifies a received signal input from the input terminal 1 and supplies the amplified signal to a mixer (MIX) 3. The MIX 3 mixes the signal from the low noise amplifier 4 and the signal from the local oscillator 4 and supplies the mixed signal to the distributor 5. The distributor 5 distributes the signal supplied from the MIX 3 to the filter switching circuit 19.

The filter switching circuit 19 comprises a switch 8, a wide-band IF band-pass filter 6, and a narrow-band IF band-pass filter 7. The switch 8 is switched by manually operating an operation switch 21. The received signal input through the distributor 5 is switched to one of the wideband IF bandpass filter 6 and the narrowband IF bandpass filter 7 and input. . The output of the filter switching circuit 19 is supplied to the IF amplifier 9, amplified, and output.

[0004] A received signal input from an input terminal 1 is supplied to a low noise amplifier 2, amplified, and then supplied to a MIX 3. The signal supplied to MIX3 is a local oscillator 4
After being mixed with the signal supplied from the filter switching circuit 19, the signal is supplied to the distributor 5 and distributed to the filter switching circuit 19. First, the switch 8 is switched so that the signal passes through the wideband IF bandpass filter 6. Therefore, the signal supplied from the distributor 5 to the filter switching circuit 19 passes through the wide-band IF band-pass filter 6, is supplied to the IF amplifier 9, is amplified, and is output.

At this time, if the output signal has an interference with the demodulated signal due to the adjacent channel signal, the signal supplied from the distributor 5 to the filter switching circuit 19 is narrowed by manually operating the operation switch 21. The switch 8 of the filter switching circuit 19 is switched so as to pass through the band IF band-pass filter 7. As a result,
The signal that has passed through the narrow-band IF bandpass filter 7 is output from the filter switching circuit 19. As a result, interference with the demodulated signal due to the adjacent channel signal is removed or reduced.

As described above, in the FPU receiving apparatus, the filter switching circuit 19 for switching between the wideband IF bandpass filter 6 and the narrowband IF bandpass filter 7.
Are used to remove and reduce interference with demodulated signals due to adjacent channel signals.

When the switch 8 is switched by manually operating the operation switch 21 to use the narrow-band IF band-pass filter 7, some multiplexed audio signals cannot be demodulated. Therefore, it is desired to use the wideband IF bandpass filter 6 as much as possible.

[0008]

However, in the prior art in which the wide-band IF band-pass filter 6 and the narrow-band IF band-pass filter 7 are manually switched by operating the operation switch 21, the following technique is used. There was an issue with problems. The first problem is that it is necessary to manually perform the switching by operating the operation switch 21, and therefore, it is necessary to constantly monitor the received demodulated signal during operation. For this reason, during operation,
This puts a burden on those who are monitoring.

The second problem is that the presence / absence of the adjacent channel signal can be determined only by the received demodulated signal, so that once the narrow band IF bandpass filter 7 is switched, the presence / absence of the adjacent channel signal can be determined. Therefore, the opportunity to switch the narrowband IF bandpass filter 7 to the wideband IF bandpass filter 6 cannot be recognized.

The present invention has been made in view of such a situation, and automatically switches between a wideband IF bandpass filter and a narrowband IF bandpass filter based on a received signal. Things.

[0011]

According to a first aspect of the present invention, there is provided a receiving apparatus, wherein first filter means for passing a first band of an input signal of a predetermined channel, and second filter for passing a second band of the input signal. Second filter means; switching means for switching a signal path so that the input signal passes through one of the first filter means and the second filter means; and an input signal adjacent to a channel adjacent to a channel of the input signal. Detecting means for detecting whether or not the signal of the channel is included; and detecting the input signal according to the detection result by the detecting means.
And control means for controlling the switching means so as to pass through one of the filter means and the second filter means. Further, the first filter means is a wide band IF band pass filter, and the second filter means is a narrow band IF band pass filter. When any one of the signals of the adjacent channels adjacent to the side is detected, the control means controls the switching means so that the input signal passes through the second filter means. When neither the signal of the adjacent channel to be detected nor the signal of the lower adjacent channel is detected, the control means controls the switching means so that the input signal passes through the first filter means. it can.
Further, a display means for displaying the level of the adjacent channel detected by the detection means may be further provided. Further, a distribution means for distributing the input signal to the first and second filter means and the detection means can be further provided. The receiving method according to claim 5, wherein a first filter step for passing a first band of the input signal of the predetermined channel, a second filter step for passing a second band of the input signal,
A first filter step and a second
A switching step of performing switching to execute any one of the filter steps, a detection step of detecting whether an input signal includes a signal of an adjacent channel adjacent to a channel of the input signal, and a detection step. Controlling the switching step according to the detection result,
A first filter step and a second
And a control step of controlling the switching step so that either one of the filter steps is executed. The recording medium according to claim 6,
A program capable of executing the receiving method according to claim 5 is recorded. In the receiving device and the receiving method according to the present invention, and in the recording medium, it is detected whether or not the input signal of the predetermined channel includes a signal of an adjacent channel adjacent to the channel of the input signal,
According to the detection result, control is performed so as to pass one of the first band and the second band of the input signal.

[0012]

FIG. 1 is a block diagram showing a configuration example of an embodiment of an FPU (Field Pickup Unit) receiving apparatus to which the receiving apparatus of the present invention is applied. 2, the same components as those of the conventional FPU receiving apparatus shown in FIG. 2 are denoted by the same reference numerals.

Low noise amplifier 2 constituting FPU receiver
Are configured to amplify a received signal input from the input terminal 1 and supply the amplified signal to a mixer (MIX) 3. MIX
3 mixes the signal supplied from the low-noise amplifier 2 with the signal supplied from the local oscillator 4 and supplies the mixed signal to the distributor 5. The distributor 5 distributes the signal supplied from the MIX 3 and supplies the signal to the filter switching circuit 19 and the adjacent channel signal detection circuit 20, respectively.

The filter switching circuit 19 comprises a switch 8, a wide-band IF band-pass filter 6, and a narrow-band IF band-pass filter 7, and is controlled by a control signal supplied from an adjacent channel signal detection circuit 20. 8 is switched, and a signal that has passed through one of the wideband IF bandpass filter 6 and the narrowband IF bandpass filter 7 is supplied to the IF amplifier 9 in the next stage.

The adjacent channel signal detection circuit 20 includes a distributor 10, an upper adjacent channel IF bandpass filter 11, and a lower adjacent channel IF bandpass filter 1.
2 and the upper adjacent channel IF bandpass filter 11
First level detector 13 for detecting the level of the output signal of
And a second level detector 14 for detecting the level of the output signal of the lower adjacent channel IF bandpass filter 12
And a level detected by the first level detector 13 and a predetermined set value, and a first comparator 15 for supplying a comparison result to an OR element 18 described later, and a second level detector 14 The level detected by the second comparator 16 is compared with a predetermined set value, and the comparison result is supplied to the OR element 18, the output signal of the first comparator 15, and the output signal of the second comparator 16. The logical sum of the output signals is calculated, and the calculation result is supplied to the switch 8 of the filter switching circuit 19 as a control signal.
And an R element 18.

Next, the operation will be described. The received signal input from the input terminal 1 is supplied to the low noise amplifier 2, amplified, and then supplied to the MIX 3. MIX3
Is supplied to the distributor 5 after being mixed with the signal supplied from the local oscillator 4, and distributed to the filter switching circuit 19 and the adjacent channel signal detection circuit 20. First, the switch 8 is switched so that the signal passes through the wideband IF bandpass filter 6. Therefore, the signal supplied from the distributor 5 to the filter switching circuit 19 passes through the wideband IF bandpass filter 6 and
It is supplied to the amplifier 9, amplified, and output.

On the other hand, the signal supplied to the adjacent channel signal detection circuit 20 is distributed by the distributor 10 and supplied to the upper adjacent channel IF band pass filter 11 and the lower adjacent channel IF band pass filter 12. The signal passing through the upper adjacent channel IF bandpass filter 11 is supplied to a first level detector 13, and the signal passing through the lower adjacent channel IF bandpass filter 12 is supplied to a second level detector 14. You.

The first level detector 13 detects the level of the upper adjacent channel signal passing through the upper adjacent channel IF band-pass filter 11, and outputs an output signal corresponding to the detection result to the first comparator 15, And display element 17
To supply. The first comparator 15 compares the signal level detected by the first level detector 13 with a predetermined set value based on the signal supplied from the first level detector 13, If the signal level detected by the level detector 13 is equal to or higher than a predetermined set value, it is considered that a signal of the upper adjacent channel has been detected, and a control signal of a predetermined level (high level) is output. On the other hand, if the signal level detected by the first level detector 13 is smaller than a predetermined set value, it is considered that no signal of the upper adjacent channel has been detected, and no control signal is output.

The second level detector 14 detects the level of the lower adjacent channel signal passing through the lower adjacent channel IF band-pass filter 12, and outputs an output signal corresponding to the detection result to the second adjacent channel signal. It is supplied to the comparator 16 and the display element 17. The second comparator 16 compares the signal level detected by the second level detector 14 with a predetermined set value based on the signal supplied from the second level detector 14, When the signal level detected by the level detector 14 is equal to or higher than a predetermined set value, it is regarded that a signal of the lower adjacent channel has been detected, and a control signal of a predetermined level (high level) is output. On the other hand, when the signal level detected by the second level detector 14 is smaller than a predetermined set value, it is regarded that the signal of the lower adjacent channel has not been detected, and the control signal is not output.

The OR element 18 performs an OR operation on the control signal supplied from the first comparator 15 and the control signal supplied from the second comparator 16, and responds to the operation result. Is supplied to the switch 8 of the filter switching circuit 19. That is, when a control signal of a predetermined level (high level) is supplied from at least one of the first comparator 15 and the second comparator 16, the OR element 18 has a predetermined level (high level). Output a control signal.

Next, the operation of the embodiment of FIG. 1 when switching between the wideband IF bandpass filter 6 and the narrowband IF bandpass filter 7 in accordance with the received signal input from the input terminal 1 will be described. I do. Normal,
When only the desired signal is received, the received signal distributed by the distributor 5 and supplied to the adjacent channel signal detection circuit 20 includes the upper adjacent channel IF band-pass filter 11 and the lower adjacent channel IF Since neither of the bandpass filters 12 passes, neither the first level detector 13 nor the second level detector 14 can detect a signal of an adjacent channel.

Accordingly, since no control signal is output from either the first comparator 15 or the second comparator 16,
No control signal is supplied to the filter switching circuit 19. For this reason, the received signal supplied to the filter switching circuit 19 via the distributor 5 passes through the wideband IF bandpass filter 6.

On the other hand, when the desired signal and the signal of the upper adjacent channel are received, the signal is distributed by the distributor 5 and
Only the upper adjacent channel signal component of the received signal supplied to the adjacent channel signal detection circuit 20 is passed by the upper adjacent channel IF band-pass filter 11, and the level is detected by the first level detector 13. The detection result is supplied to the first comparator 15 and the first comparator 15
In, the signal level detected by the first level detector 13 is compared with a set value. As a result, when the detected signal level is equal to or higher than the set value, the control signal is output.

Therefore, a control signal is supplied to the switch 8 of the filter switching circuit 19 via the OR element 18 and the distributor 5
, The received signal supplied to the filter switching circuit 19 passes through the narrow-band IF band-pass filter 7. In the display element 17, the first level detector 1
3 indicates the level detected.

When the desired signal and the signal of the lower adjacent channel are received, the received signal distributed by the distributor 5 and supplied to the adjacent channel signal detection circuit 20 is transmitted to the lower adjacent channel IF. In the band-pass filter 12, only the lower adjacent channel signal component is passed, and the level is detected by the second level detector 14. The detection result is supplied to the second comparator 16 and the second comparator 16
In, the signal level detected by the second level detector is compared with a set value. As a result, when the detected signal level is equal to or higher than the set value, the control signal is output.

Accordingly, a control signal is supplied to the switch 8 of the filter switching circuit 19 via the OR element 18 and the distributor 5
, The received signal supplied to the filter switching circuit 19 passes through the narrow-band IF band-pass filter 7. In the display element 17, the second level detector 1
4 indicates the detected level.

When the desired signal, the signal of the upper adjacent channel, and the signal of the lower adjacent channel are received, the control signal is output from both the first comparator 15 and the second comparator 16. Is supplied to the OR element 18. Accordingly, a control signal is supplied to the switch 8 of the filter switching circuit 19 via the OR element 18, and the signal supplied to the filter switching circuit 19 via the distributor 5 passes through the narrow band IF band-pass filter 7. Become like The display element 17 displays, for example, the larger of the signal level detected by the first level detector 13 and the signal level detected by the second level detector 14.

As described above, the following effects can be obtained in the above embodiment. A first effect is that it is not necessary to constantly monitor the presence or absence of interference of a received demodulated signal by an adjacent channel signal during operation.
The second effect is that when there is no adjacent channel signal,
Since the IF band pass filter can be automatically switched to the wide band side, it is possible to prevent the operation from continuing while the received signal passes through the narrow band IF band pass filter 7. The reason is,
Detects the presence or absence of an adjacent channel signal and automatically
This is because a means for switching the band of the bandpass filter (adjacent channel signal detection circuit 20) is provided.

In the above embodiment, the case where the present invention is applied to the FPU receiving apparatus has been described.
The present invention can be applied to other receiving apparatuses.

The circuit configuration in the above embodiment is an example, and the present invention is not limited to this.

In the above embodiment, the case where the present invention is realized by hardware has been described. However, the present invention can be realized by software.

[0032]

As described above, according to the receiving apparatus, the receiving method, and the recording medium of the present invention, an input signal of a predetermined channel includes a signal of an adjacent channel adjacent to the channel of the input signal. Is detected or not,
According to the detection result, control is performed so as to pass one of the first band and the second band of the input signal. Therefore, the band of the band-pass filter through which the input signal passes depends on the reception condition. Can be automatically switched. Accordingly, interference with the demodulated signal of the predetermined channel due to the signal of the adjacent channel can be removed or reduced, and efficient operation becomes possible.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration example of an embodiment of an FPU receiving device to which the receiving device of the present invention is applied.

FIG. 2 is a block diagram illustrating a configuration example of a conventional FPU receiving device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Input terminal 2 Low noise amplifier 3 MIX 4 Local oscillator 5 Distributor 6 Broadband IF bandpass filter 7 Narrowband IF bandpass filter 8 Switch 9 IF amplifier 10 Distributor 11 Upper adjacent channel IF bandpass filter 12 Lower adjacent channel IF band-pass filter 13 first level detector 14 second level detector 15 first comparator 16 second comparator 17 display element 18 OR element 19 filter switching circuit 20 adjacent channel signal detection circuit 21 operation switch

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[Procedure amendment]

[Submission date] July 26, 1999 (1999.7.2)
6)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Name of invention

[Correction method] Change

[Correction contents]

[Title of the Invention] Receiving device

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0001

[Correction method] Change

[Correction contents]

[0001]

TECHNICAL FIELD The present invention relates to a receiving device ,
In particular, by detecting whether a signal component of an adjacent channel is included in a received signal of a predetermined channel,
The present invention relates to a receiving apparatus that switches and supplies a received signal to one of a wideband and a narrowband IF bandpass filter.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0011

[Correction method] Change

[Correction contents]

[0011]

A receiving apparatus according to claim 1.
Location includes a first filter means for passing a first band of the input signal of a predetermined channel, a second filter means for passing a second band of the input signal, the input signal is, first filter means Switching means for switching a signal path so as to pass through either one of the first and second filter means, and a first adjacent means adjacent to an upper side of the channel of the input signal.
Third filter means for passing the channel signal;
A second adjacent channel below the channel of the input signal;
Fourth filter means for passing the signal of the
A first neighbor adjacent to the signal above the channel of the input signal
First detecting means for detecting the level of a signal of a channel in contact
And the input signal adjacent to the lower side of the input signal channel
A second detecting a level of a signal of a second adjacent channel;
Detecting means, and the first detecting means and the second detecting means.
Depending on the detection result, the input signal is changed by the first filter means and the first filter means.
And second filter means.
Control means for controlling switching means, and first detection means
First adjacent channel corresponding to the detection result output from
Signal level and the detection output from the detection means 2
Of the level of the signal of the second adjacent channel corresponding to the result
The larger of the levels is displayed and the first detector
A first adjacent channel by the step and the second detecting means;
Signal level and the second adjacent channel signal level.
Display nothing when none of the levels are detected
A display element, and the first filter means includes a broadband IF.
A band-pass filter, wherein the second filter means
Band IF band-pass filter, the first detecting means and
And at least one of the second detection means,
Signal of one adjacent channel and second adjacent channel
That at least one of the signals is detected
Control means, the input signal passing through the second filter means
The switching means is controlled so that the first detecting means and the
Signal of the first adjacent channel by the second detecting means.
Signal and the signal of the second adjacent channel are both detected.
If not, the control means determines whether the input signal is
The switching means is controlled so as to pass through the step . In the receiving apparatus according to the present invention, the first filter means passes the first band of the input signal of the predetermined channel, the second filter means passes the second band of the input signal, and the switching means The signal path is switched so that the input signal passes through one of the first filter means and the second filter means, and the third filter means
A first adjacent channel adjacent above the channel of the input signal;
Channel signal, and the fourth filter means
A second adjacent channel below the channel of the signal
And the first detecting means converts the input signal to the input signal.
First adjacent channel above the channel of the signal
And the second detection means detects the level of the
A second adjacent channel below the channel of the input signal;
The control means detects the level of the signal of the channel.
Means according to the detection result by the means and the second detection means.
A first filter means and a second filter means;
Control the switching means to pass either one of
The display element detects the detection result output from the first detection means.
The level of the signal of the first adjacent channel corresponding to the result;
2 corresponding to the detection result output from the second detection means.
The higher of the adjacent channel signal levels
A first detecting means and a second detecting means.
Depending on the stage, the level of the signal of the first adjacent channel and
And the level of the signal of the second adjacent channel
If nothing is displayed, nothing is displayed. At this time, the first file
The filtering means is a wideband IF bandpass filter;
The second filter means is a narrow band IF band pass filter
And the number of the first detecting means and the second detecting means is small.
Either way, the signal of the first adjacent channel and the
And at least one of the signals of the second adjacent channel
When either one of them is detected, the control means sets the input signal to
The switching means is controlled to pass through the second filter means.
Control, by the first detecting means and the second detecting means,
The signal of the first adjacent channel and the second adjacent channel
If no control signal is detected, the control means
Switch so that the force signal passes through the first filter means
Control means.

[Procedure amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0032

[Correction method] Change

[Correction contents]

[0032]

As described above, according to the receiving apparatus of the present invention, the first filter means passes the first band of the input signal of the predetermined channel, and the second filter means outputs the first band of the input signal. 2 band, and the switching unit switches the signal path so that the input signal passes through one of the first filter unit and the second filter unit .
Filter means adjacent to the upper side of the input signal channel.
Pass the signal of the first adjacent channel, and
Filter means adjacent to the lower side of the channel of the input signal.
Pass the signal of the adjacent channel of
The first signal adjacent to the input signal above the channel of the input signal
And the second detection
Means are adjacent to the input signal below the channel of the input signal.
Detecting and controlling the level of the signal of the second adjacent channel
Means for detecting by the first detecting means and the second detecting means
Depending on the result, the input signal is passed through the first filter means and the second
Cut through one of the two filter means
Controlling the switching means, and the display element is output from the first detecting means.
The signal of the first adjacent channel corresponding to the input detection result
Signal level and the detection result output from the detection means 2
Of the signal levels of the corresponding second adjacent channel,
The higher level is displayed, and the first detecting means and
Signal of the first adjacent channel by the second detecting means.
Signal level and signal level of the second adjacent channel
If none of the above is detected, nothing is displayed. this
At this time, the first filter means includes a broadband IF bandpass filter.
And the second filter means is a narrow band IF band.
A first detection means and a second detection means.
The first adjacent channel by at least one of the output means.
Channel signal and the second adjacent channel signal
Control means when at least one of
Is switched off so that the input signal passes through the second filter means.
Controlling the switching means, the first detecting means and the second detecting means.
By means of the signal of the first adjacent channel and the second
When none of the signals of adjacent channels of is detected,
The control means passes the input signal through the first filter means
Since the switching means is controlled as described above, it is possible to automatically switch the band of the band-pass filter through which the input signal passes according to the reception state. Accordingly, interference with the demodulated signal of the predetermined channel due to the signal of the adjacent channel can be removed or reduced, and efficient operation becomes possible.

Claims (6)

[Claims] A first filter unit that passes a first band of an input signal of a predetermined channel; a second filter unit that passes a second band of the input signal; Switching means for switching a signal path so as to pass through one of the first filter means and the second filter means; and whether or not the input signal includes a signal of an adjacent channel adjacent to a channel of the input signal. Detecting means for detecting whether the input signal passes through one of the first filter means and the second filter means in accordance with a detection result by the detecting means. A receiving device comprising a control unit. 2. The method according to claim 1, wherein said first filter means includes a wideband IF.
A band-pass filter, wherein the second filter means is a narrow-band IF band-pass filter, and the detection means detects a signal of an adjacent channel adjacent to the upper side of the channel and a signal of an adjacent channel adjacent to the lower side. When at least one of the signals is detected, the control unit determines that the input signal is the second signal.
Controlling the switching means to pass through the filter means of, when the detection means does not detect the signal of the adjacent channel adjacent to the upper side of the channel and the signal of the adjacent channel adjacent to the lower side, The receiving device according to claim 1, wherein the control unit controls the switching unit so that the input signal passes through the first filter unit. 3. The receiving device according to claim 1, further comprising a display unit that displays a level of the adjacent channel detected by the detection unit. 4. The receiving apparatus according to claim 1, further comprising a distribution unit that distributes the input signal to the first filter unit, the second filter unit, and the detection unit. 5. A first filter step for passing a first band of an input signal of a predetermined channel; a second filter step for passing a second band of the input signal; A switching step of performing switching to execute one of the first filter step and the second filter step; and the input signal includes a signal of an adjacent channel adjacent to a channel of the input signal. A detection step of detecting whether or not the input signal is subjected to one of the first filter step and the second filter step in accordance with a detection result of the detection step A control step of controlling the switching step as described above. 6. A recording medium on which a program capable of executing the receiving method according to claim 5 is recorded.