JPH05328359A - Bs/cs judging device - Google Patents

Abstract

PURPOSE:To automatically judge BS/CS and to adjust an amplitude level corresponding to the judged BS/CS by judging whether a MUSE signal is received from a broadcasting satellite(BS) or a communication satellite(CS) from the amplitude value of an extracted dispersal signal. CONSTITUTION:A BS/CS signal obtained by being superposed by a dispersal signal to a MUSE base band analog signal is supplied to an input terminal Vin and only the dispersal signal component is extracted by an LPF 1. The dispersal signal component is compared with a prescribed judging level by a comparator circuit 7 an amplifier 3 and through a detector 5, whether the input signal is a signal from the BS or the CS is judged and the judged result is displayed on a BS/CS display device 9. Consequently the judgement of BS/CS can be automatically displayed, and in the case of removing the dispersal signal by reverse phase addition, the amplitude level corresponding to the BS/CS result can be automatically adjusted.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a broadcasting satellite (Broadc).
astating Satellite (hereinafter also simply referred to as BS) and communication satellites (Communications S)
The present invention relates to a BS / CS determination device that determines a BS or a CS in a device that shares a reception system of MUSE signals transmitted from each of the atellite (hereinafter also simply referred to as CS).

[0002]

2. Description of the Related Art In recent years, satellite broadcasting in which broadcasting radio waves transmitted from an earth station are directly broadcast to a final user on the ground via a broadcasting satellite and satellite communication using a communication satellite as a relay station for long-distance communication have become widespread. It's starting. In addition, these broadcasting satellites (BS)
Radio waves transmitted from the MU and the communication satellite (CS) respectively.
There is a receiving device that receives an SE signal by sharing a receiving system.

As is well known, the dispersal signal is used for FM modulation by superimposing it on the main signal so that the energy of the radio wave is not biased to a specific frequency. Energy density per unit frequency of ITU (International Telecommunication Union) WA
It is set within the allowable value determined by RC-BS (World Radio Administration Conference on Broadcast Satellite).

That is, since the limit of the ground electric field flux density per 1 Hz is determined for the radio wave of BS, it is not preferable that the energy concentrates on one certain frequency. Therefore, the dispersal signal is multiplexed with the video signal to FM. I try to modulate it.

Generally, in the high-definition broadcasting, in order to remove the dispersal component from the MUSE signal on which the dispersal signal is superimposed, the method of clamping the horizontal blanking portion is the simplest.

FIG. 9 shows a configuration according to this method. In FIG. 9, BS / CS in which the dispersal signal is superimposed on the MUSE baseband analog signal from the input terminal Vin
Signal is supplied.

This signal is supplied to the capacitor 140 via the buffer amplifier 139 to remove the DC component, and then is introduced to the adder 141. In the adder 141, the clamp level signal from the clamp circuit 137 is added to remove the dispersal component. The clamp level signal from the clamp circuit 137 is output by switching in synchronization with the clamp pulse.

Further, when the dispersal signal component is removed more completely, or when the ratio of the dispersal signal component is relatively large as in the case of CS reception, a waveform opposite to the dispersal signal is generated in the receiving system. Then, it is said that it is preferable to perform the anti-phase addition dispersal signal removal in which this is mixed and removed.

FIG. 10 shows a block diagram when the dispersal signal is removed by the anti-phase addition. From the input terminal Vin, the dispersal signal is superimposed on the MUSE baseband analog signal and a signal corresponding to BS / CS is supplied.

This signal is supplied to the adder 241 via the buffer amplifier 239. In the adder 241, the analog switch 23 is operated after the level adjustment 235 adjusts the level of the reverse dispersal signal generated by the reverse dispersal signal generation circuit 233 according to BS / CS.
At 7, the PLL is supplied only when LOCK, and the signal obtained by removing the dispersal signal from the main signal is the output terminal V
It is output from out.

The BS in the level adjustment 235
The level adjustment according to / CS is manually performed every time regardless of BS / CS.

[0012]

However, the BS for removing the dispersal signal by the conventional anti-phase addition is used.
BS / CS for high-definition broadcasting by CS / CS
In a device that shares a receiver for the reception of
Since it was not possible to determine whether the radio wave was from the CS or the radio wave from the CS, when removing the dispersal signal by anti-phase addition, the level adjustment had to be done manually each time, which was very annoying. It was.

The present invention has been made in view of the above problems, and in a device that shares a receiver in high-definition broadcasting by BS / CS, it is automatically judged whether BS / CS is displayed, and a dispersal signal is displayed. It is an object of the present invention to provide a BS / CS determination device capable of automatically adjusting the amplitude level according to BS / CS when the removal is performed by anti-phase addition.

[0014]

In order to achieve the above object, the first invention of the present application is an extraction means for extracting a dispersal signal to be superimposed on a MUSE signal transmitted from a broadcasting satellite and a communication satellite, respectively, and the extraction means. The gist of the present invention is to have a determining means for determining whether the MUSE signal is a broadcasting satellite or a communication satellite from the amplitude value of the dispersal signal extracted by the means.

The second invention of the present application is the extraction means for extracting the dispersal signal superimposed on the MUSE signal transmitted from each of the broadcasting satellite and the communication satellite, and the amplitude of the dispersal signal extracted by this extraction means. The gist is to have an adjusting means for adjusting the amplitude level of the broadcasting satellite or the communication satellite when removing the dispersal signal from the MUSE signal by anti-phase addition according to the value.

The third invention of the present application is an extraction means for extracting the dispersal signal superimposed on the MUSE signal,
The gist of the present invention is to have display means for displaying whether the MUSE signal is a broadcasting satellite or a communication satellite based on the amplitude value of the dispersal signal extracted by the extracting means.

[0017]

The BS / CS determination device of the first invention of the present application is
The extraction means extracts the dispersal signals to be superimposed on the MUSE signals transmitted from the broadcasting satellite and the communication satellite, respectively, and determines the amplitude values of the BS-time amplitude and the CS-time amplitude of the extracted dispersal signal. It is determined from the difference whether the MUSE signal is a broadcasting satellite or a communication satellite.

The BS / CS determining device of the second invention of the present application is
The extraction means extracts the dispersal signal to be superimposed on the MUSE signal transmitted from each of the broadcasting satellite and the communication satellite, and sets the amplitude level corresponding to the broadcasting satellite or the communication satellite according to the amplitude value of the extracted dispersal signal. Adjust to remove the dispersal signal from the MUSE signal by anti-phase addition.

The BS / CS determination device of the third invention of the present application is
The extraction means extracts the dispersal signal superimposed on the MUSE signal, and displays on the display means which one of the broadcasting satellite and the communication satellite the MUSE signal belongs to based on the amplitude value of the extracted dispersal signal. To do.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings.

FIG. 1 shows the BS and CS described in this embodiment.
FIG. 3 is a block diagram of a BS / CS determination device that performs BS / CS determination by detecting the level of a dispersal signal superimposed on a MUSE signal when a receiver is shared in high-definition broadcasting by radio waves from the.

The BS / CS judging device shown in FIG. 1 includes a low-pass filter 1, an amplifier 3, a detector 5, a comparator circuit 7, a BS / CS indicator 9 and a threshold level generating circuit 1.
It is composed of 1.

As shown in the frequency characteristic diagram of the LPF 1 of FIG. 3, the low-pass filter (hereinafter, also simply referred to as LPF) 1 is superimposed with a dispersal signal corresponding to BS / CS input to the input terminal Vin. 30 including dispersal signal component in MUSE baseband analog signal
It allows only low frequency components below Hz to pass.

The amplifier 3 connected to the low pass filter 1 amplifies the dispersal signal component. Further, the detector 5 connected to the amplifier 3 performs full-wave rectification of the signal amplified by the amplifier 3. The comparator circuit 7 connected to the detector 5 is also connected to the threshold level generation circuit 11 and outputs the comparison result to the connected BS / CS display 9.

Next, the operation will be described with reference to FIGS. 1 to 5 of this embodiment. From the input terminal Vin shown in FIG. 1, a signal related to high-definition broadcasting is supplied from the BS in which the dispersal signal is superimposed on the MUSE baseband analog signal as shown in FIG. As shown in FIG. 2, the dispersal signal is overlapped with the horizontal blanking period of the MUSE signal as a cycle, and the line midpoint (NO.563), which is the midpoint of the 1125 scanning lines of high-definition broadcasting. As for the signal level (amplitude value) at, BS is E _BS , while CS is E _CS.
Is.

That is, since the dispersal signal level is the maximum frequency deviation (ΔF): frame pulse level = dispersal signal frequency deviation: dispersal signal level, when the frame pulse level is 0.5 V, BS when _{10.2MHz: 0.5V = 600KHz PP: E} BS Thus, E _BS = 29.4mV _PP CS during _{9.6MHz: 0.5V = 1.1MHz PP: E} CS Therefore, in the E _CS = 57.29mV _PP , Each required.

The signal supplied from the input terminal Vin is guided to the low pass filter (LPF) 1 and only the dispersal signal component is extracted. The amplitude level of the signal extracted by the low-pass filter 1 (FIG. 4A) is appropriately amplified by the amplifier 3 (FIG. 4B) and is guided to the detector 5. As shown in FIG. 5, the detector 5 performs full-wave rectification of this amplified signal (FIG. 5 (a)) and outputs it to the comparator circuit 7 (FIG. 5 (b)).

In this comparator circuit 7, the intermediate value between the full-wave rectification level when receiving the signal from CS and the full-wave rectification level when receiving the signal from BS (see FIG. 5).
(Indicated by a dotted line in (c)) is set as the determination level, and the signal level from the detector 5 is higher than the set determination level, the signal from CS and the lower level is the signal from BS. BS / CS
It is output to the display unit 9 to display that it is BS or CS.

Next, referring to the block diagram shown in FIG.
A case will be described in which whether the BS / CS is automatically determined and the dispersal signal is removed by anti-phase addition.

The BS / CS judging device shown in FIG. 6 has a low-pass filter 21, an amplifier 23, a detector 25, a comparator circuit 27, a BS / CS indicator 29, and an attenuator 3.
1, inverse dispersal signal generation circuit 33, AGC (Au
The circuit is composed of a tomatic gain control (automatic gain control) circuit 35, an analog switch 37, a buffer amplifier 39, an adder 41 and a PLL circuit 43. The low-pass filter 21, the amplifier 23, the detector 25, the comparator circuit 27, and the BS / CS display 2
The configuration of 9 is the same as that of the first embodiment described above, and the description thereof will be omitted.

The attenuator 31 adjusts the output of the detector 5 to adjust the sensitivity of the connected AGC circuit 35. In addition, this reverse dispersal signal generation circuit 33
Is for generating a dispersal signal having a phase opposite to that of the dispersal signal superimposed on the MUSE baseband analog signal input from the input terminal Vin. The AGC circuit 35 automatically adjusts the reverse dispersal signal level by following the fluctuation of the dispersal signal level. The analog switch 37 supplies the level-adjusted reverse dispersal signal to the adder 41 in response to a lock signal from a PLL circuit 43 described later. The adder 41 converts the MUSE baseband analog signal supplied via the buffer amplifier 39 into the AGC circuit 3
The inverse dispersal signal from 5 is added to the MUSE
This is for removing the dispersal signal superimposed on the baseband analog signal. The MUSE baseband analog signal from which the dispersal signal has been removed by the adder 41 is output from the output terminal Vout and also the PLL.
It is supplied to the circuit 43.

PLL (Phase Locked Lo)
The op) circuit 43 is a feedback loop used for demodulating a baseband signal from a frequency-modulated carrier. Since there is a possibility that a phase shift occurs until the PLL circuit 43 is locked, when the PLL circuit 43 is locked, the analog switch 3 described above is locked.
A lock signal is sent to 7 to close the switch. Further, since the synchronization signal in the PLL circuit 43 is supplied to the reverse dispersal signal generation circuit 33, the reverse dispersal signal synchronized with the dispersal signal superimposed on the MUSE baseband analog signal is converted into the MUSE baseband analog signal. Can be added to.

Next, the operation of the BS / CS judging device shown in FIG. 6 will be described with reference to FIGS. 7 and 8. FIG. 7 and FIG. 8 show a state where a MUSE baseband analog signal is extracted by adding an antiphase dispersal signal to the dispersal signal superimposed on the MUSE baseband analog signal from CS and BS input from the input terminal Vin, respectively. Is shown.

That is, the BS / CS determining device by detecting the dispersal signal level according to the present embodiment is
BS that extracts the dispersal signal superimposed on the E signal
The judgment level is set to the intermediate value of the difference between the time amplitude and the CS time amplitude, and BS /
After the CS is determined, the dispersal signal waveform (BS / CS) superimposed on the MUSE signal is supplied with the anti-phase dispersal signal generated by the inverse dispersal signal generation circuit 33 based on the determination result. The dispersal signal is removed by adding the generated AGC output so as to have the same amplitude as the signal.

As described above, according to this embodiment, B
In a device that shares reception in high-definition broadcasting by S or CS, BS / CS can be automatically determined and the amplitude level is automatically adjusted according to the reception of BS radio waves and the reception of CS radio waves. It can be carried out. As a result, it becomes possible to automatically remove the dispersal signal by anti-phase addition.

[0036]

As described above in detail, according to the present invention, B
BS by detecting the level of the dispersal signal superimposed on the MUSE signal in high-definition broadcasting by S / CS
/ CS can be determined, and the amplitude level at BS / CS for removing the dispersal signal by anti-phase addition can be automatically adjusted.

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of a BS / CS determination device by detecting a level of a dispersal signal according to an embodiment of the present invention.

FIG. 2 is a diagram showing waveforms of BS and CS dispersal signals superimposed on a MUSE signal according to the present invention, respectively.

3 is a frequency characteristic diagram of a low-pass filter in the block diagram shown in FIG.

4 is the BS of the amplifier in the block diagram shown in FIG.
It is a figure which shows the output waveform at the time of CS and CS, respectively.

5 is a block diagram of a comparator circuit for BS or CS based on the output level of the detector in the block diagram shown in FIG.
FIG. 6 is a diagram for explaining a process of performing the determination of FIG.

FIG. 6 is a block diagram showing a configuration in the case of removing a dispersal signal by anti-phase addition based on BS / CS determination according to the present invention.

7 is a waveform diagram for explaining removal of a dispersal signal by anti-phase addition at the time of CS in the block diagram shown in FIG.

8 is a waveform diagram for explaining removal of a dispersal signal by anti-phase addition at BS in the block diagram shown in FIG.

FIG. 9 is a block diagram showing a configuration of a conventional dispersal signal removal circuit.

FIG. 10 is a block diagram showing a configuration of a dispersal signal removal circuit by anti-phase addition according to a conventional example.

[Explanation of symbols]

 1 Low-pass filter 3 Amplifier 5 Detector 7 Comparator circuit 9 BS / CS indicator 11 Threshold level generating circuit 21 Low-pass filter 23 Amplifier 25 Detector 27 Comparator circuit 29 BS / CS indicator 31 Attenuator 33 Reverse dispersal signal generating circuit 35 AGC 37 analog switch 39 buffer amplifier 41 adder 43 PLL circuit

Claims (3)

[Claims] 1. Extraction means for extracting a dispersal signal to be superimposed on MUSE signals transmitted from a broadcasting satellite and a communication satellite respectively, and the MUSE signal is broadcast from the amplitude value of the dispersal signal extracted by the extraction means. A BS / CS judging device comprising: a judging unit for judging whether the satellite is a communication satellite or a communication satellite. 2. Extraction means for extracting a dispersal signal to be superimposed on MUSE signals respectively transmitted from a broadcasting satellite and a communication satellite, and the MUSE signal according to the amplitude value of the dispersal signal extracted by this extraction means. BS / CS determination device, comprising: adjusting means for adjusting an amplitude level of a broadcasting satellite or a communication satellite when the dispersal signal is removed by anti-phase addition. 3. Extraction means for extracting a dispersal signal superimposed on a MUSE signal, and the MUSE signal is either a broadcasting satellite or a communication satellite based on the amplitude value of the dispersal signal extracted by the extraction means. A BS / CS determination device, comprising: a display unit that displays whether or not