JPH10190505A - Satellite broadcasting receiving device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To transmit the entire broadcasting signals of plural satellites to a reception end by means of one co-axial cable in an inexpensive method by effectively utilizing an existing satellite broadcasting receiving device and only adding a simple device. SOLUTION: A second CS satellite signal is reversely converted into a frequency higher than a CS-IF band in a frequency axis by providing block converters 9a and 9b in the outputs of the converters 8a and 8b of an antenna 6, mixes with another satellite signal and transmitted to the reception end by one co-axial cable 22. In the reception end, the signal reversely transmitted by a reverse converter 19 is demodulated and received by a CS tuner by re- reverse coverstion into the CS-IF band. With respect to the first CS signal, the signal transmitted by the CS-IF band is received as it is by permitting the reverse converter 19 to be through.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for receiving a plurality of satellite signals individually transmitted from a plurality of satellites and scattered over a wide band with a plurality of antennas and mixing the received signals to form a single signal. And transmits the signal to the receiver side by using the coaxial cable described above, and the receiver side selects an arbitrary channel from the transmitted signals to enable reception.

[0002]

2. Description of the Related Art VHF and UHF terrestrial broadcast signals are received by dedicated antennas, respectively, transmitted to a receiving end via a coaxial cable or the like without being converted to an intermediate frequency, and can be received by a television receiver. (Satellite broadcasting) signal, CS
(Satellite communication) A satellite signal such as a signal is received by a parabolic antenna or the like, and a BS signal is converted to a frequency of a BS-IF band which is a first intermediate frequency band by a converter provided in the antenna.
The CS signal is separated into a vertically polarized wave and a horizontally polarized wave, and is converted into a frequency of a CS-IF band which is a second intermediate frequency band, respectively.
It is sent to the receiving end by a coaxial cable or the like. At the receiving end, the transmitted signal is demodulated by a tuner at each home or individual user and output and received by a television receiver or the like.

At this time, terrestrial broadcast signals of VHF and UHF,
Since the frequencies of the BS-IF band and the CS-IF band are different from each other in Japan and Europe as shown in FIG. 4, the terrestrial broadcast signal and the BS-IF signal are transmitted by one coaxial cable or the like. And the CS-IF signal can be mixed and transmitted to the receiving end, which is implemented.

However, when the number of satellites increases and the number of signal channels increases, the conventional IF band lacks the band,
If channel signals of different satellites are mixed and transmitted on one transmission line, overlapping occurs on the frequency axis. In that case, the receiving end cannot select a channel and cannot receive.

Therefore, as a method for preventing such interference, two or more coaxial cables (hereinafter referred to as cables) are used to transmit overlapping channels with another cable so that overlapping does not occur. Switching the receiving satellite by switching the cable or providing a switch at the head end without increasing the number of transmission cables, so that the transmitted satellite signal is switched by operation from the receiving end, so that the signals of the satellites overlap. For example, a method of setting a second intermediate frequency band other than the conventional IF band, and converting the increased channel to this frequency by a converter to prevent overlapping is considered.

[0006]

However, in the system using two or more cables, when a new satellite broadcasting receiver is installed, either one cable or two cables is installed. Although there is no big difference,
In the case of reception using two cables, the use of two cables requires time and effort to draw in a new cable, which increases the installation cost and burdens the user.

[0007] In the method of switching satellites to be transmitted at the head end, only one cable is required. Therefore, in a home where the cable has already been drawn in, it is not necessary to install a new cable. In this case, since the receiving satellite is selected at the head end, not all received signals are transmitted, so that the method is not satisfactory for each receiver. Also, in the conventional transmission method using a frequency other than the IF band, transmission using a single cable is possible, but since the conventional tuner cannot demodulate a signal in a frequency other than the IF band, a new dedicated tuner is used. Is required.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and effectively utilizes existing satellite broadcast receivers and adds only a simple device to all broadcast signals of a plurality of satellites by an inexpensive method. Is transmitted to the receiving end through a single coaxial cable to provide a satellite broadcast receiving apparatus capable of receiving.

[0009]

According to a first aspect of the present invention, there is provided a satellite broadcast receiving apparatus for receiving signals from a plurality of antennas for respectively receiving satellite signals transmitted from a plurality of satellites. A satellite broadcast receiving apparatus for mixing and transmitting at least one of the received satellite signals to an intermediate frequency higher than a second intermediate frequency band. Inverting is performed on the frequency axis and then mixed. At the receiving end, an inverting converter is provided, and the inverted signal is inverted again by the inverting converter into a first intermediate frequency band or a second intermediate frequency band. By converting, it is possible to receive with an existing tuner.

According to a second aspect of the present invention, in the satellite broadcast receiving apparatus, the inverted signal is a CS signal, and the receiving end converts the transmitted CS signal into a second intermediate frequency band by an inverting converter. By inverting again,
It is configured to demodulate into a signal that can be received by a television receiver by an existing CS tuner.

According to a third aspect of the present invention, in the satellite broadcast receiving apparatus, the inverting converter has a changeover switch for passing and outputting the input signal without inverting the input signal, and the switching can be performed using the polarization plane switching signal of the existing tuner. It is configured as follows.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a block diagram showing the configuration of a satellite broadcast receiving apparatus according to the present invention, and FIG. 2 shows a change in the frequency spectrum of the satellite broadcast receiving apparatus in the case of Europe. In FIG.
Reference numeral 1 denotes a satellite broadcasting signal received by a BS antenna, which is converted by a BS converter 2 into an intermediate frequency in the BS-IF band.
Reference numeral 3 denotes a first CS antenna which receives a satellite communication signal, separates the vertical polarization and the horizontal polarization received by the quadrature polarization splitter / demultiplexer 4, and outputs the CS-IF by the CS converters 5a and 5b.
Converted to the intermediate frequency of the band.

Reference numeral 6 denotes a second CS antenna, and a first C antenna
A CS signal different from the S antenna is received. Reference numeral 7 denotes an orthogonal polarization splitter / demultiplexer, and reference numerals 8a and 8b denote CS converters. 9a and 9b are block converters, and the signals converted into the CS-IF band frequency by the CS converter are further converted to CS-I signals by the block converters 9a and 9b.
Inversion conversion is performed on the frequency axis to a frequency higher than the F band. Reference numeral 13 denotes a mixer, in which the frequency-converted satellite signals are mixed and transmitted to the subsequent stage by one coaxial cable 23.

For example, as shown in FIG.
Satellite (FSS) signal is 11.481 to 11.695G
Hz horizontal and vertical polarization, the vertical polarization is 9.800
With a converter having a local oscillation frequency of 1 GHz,
It is converted to an intermediate frequency of 681 to 1.895 GHz, and the horizontal polarization is converted to an intermediate frequency of 1.381 to 1.595 GHz by a converter having a local oscillation frequency of 10.100 GHz. Then, the vertical polarization is inverted and converted to an intermediate frequency of 2.005 to 2.219 GHz by setting the local oscillation frequency of the block converter 9a to 1.95 GHz, and similarly, the horizontal polarization also changes the local oscillation frequency of the block converter 9b. By setting 1.95 GHz, 2.30
The frequency is inverted and converted to an intermediate frequency of 5 to 2.519 GHz, resulting in a frequency spectrum shown in FIG. The signal of the BS satellite (DBS) and the signal of the first CS satellite are converted into a BS-IF band and a CS-IF band by a converter, respectively. In Europe, the 1 GHz band may be used as the transmission band and the 2 GHz band may be used as the inversion band.

As described above, a plurality of CS satellites are provided,
If the transmission band is not sufficient with only the IF band (1.375 to 1.879 GHz), mixed transmission can be performed by one coaxial cable only by connecting a block converter after a conventional converter. The CS converter 8a,
8b local oscillation frequency of 13.7 GH for vertical polarization
If z is set to 14.0 GHz with respect to the horizontal polarization, and each of them is inverted, it is possible to obtain an inverted intermediate frequency as shown in FIG. 2B without separately providing a block converter. However, since this conversion cannot be performed by the conventional converter, a new converter is installed.

The signals from the VHF antenna 11 and the UHF antenna 12 mixed by the mixer 10 are further mixed and amplified by the booster 14 and transmitted to the subsequent stage. The output of the booster 14 is connected by one coaxial cable 22 to a tuner, a television, or the like of the individual home or individual user, which is the receiving end, via several splitters 15 and distributors 16.

At the receiving end, the transmitted signal passes through a serial unit 17, and a terrestrial broadcast signal and a satellite signal are separated by a separator 18, and the separated terrestrial broadcast signal is sent to a television receiver 21. The separated satellite signal is sent to a satellite receiving receiver 20 which is a tuner via an inverting converter 19. Satellite receiver 20 is BS
A known signal for demodulating an individual satellite broadcast signal or satellite communication signal transmitted at an intermediate frequency of -IF, CS-IF. The output can be received by the television receiver 21. The satellite receiving receiver 20 may have a built-in decoder (referred to as IRD).

Next, the inverting converter 19 will be described with reference to the block diagram of FIG. In the figure, reference numeral 25 denotes an input terminal. The input signal passes through a high-pass filter 26 and a first amplifier 27, is switched by changeover switches 28 and 35, and the signal is transmitted through either A or B path. When receiving the inverted signal, it is connected to B as shown, passes through the first band-pass filter 29a, and passes through the frequency converter 30.
, And are simultaneously inverted on the frequency axis.
After passing through the second band-pass filter 29b, the second amplifier 33, and the equalizer 34, the signal passes through the changeover switch 35 and the low-pass filter 36, and is output from the output terminal 39. When connected to the A side, frequency conversion and the like are not performed, and the signal input from the input terminal 25 is output from the output terminal 39.

Further, 31 is an oscillator, 32 is a PLL circuit,
37 is a CPU, and 40 is a constant voltage source for operating each circuit.
Reference numeral 38 denotes a voltage value discriminating circuit which has a built-in comparator and detects a signal transmitted from the satellite receiving receiver 20 for operating the changeover switches 28 and 35. The changeover switches 28 and 35 are configured so that the CPU 37 receives the changeover signal and is switched by an operation signal from the CPU 37.

The operation of the inverting converter 19 is shown in FIG.
Referring to the spectrum diagrams before and after the conversion in (b) and (c), the vertical polarization of the input signal is 2.
005 to 2.219 GHz and the horizontal polarization is 2.305 to
When receiving the inverted signal of 2.519 GHz and receiving this signal, the changeover switches 28 and 35 are connected to B,
The oscillation frequency of the oscillator 31 is set to 1.950 GHz. By performing the inversion conversion at this frequency, the vertical polarization from the output end 39 is 1.681 to 1.895 GHz, and the horizontal polarization is 1.681 GHz.
381 to 1.595 GHz, which are all converted to the CS-IF band, and become frequencies that can be demodulated by the receiver 20 for satellite reception. To receive a signal transmitted in a normal CS-IF band, the switches 28 and 35 may be connected to the A side to output without frequency conversion.

If a polarization plane switching signal provided in an existing satellite receiver is used as the switching signal, the signal of the inverting converter can be switched from the satellite receiver. The polarization plane switching signal is a signal sent to the antenna to switch the reception polarization of the antenna, and is a signal of 14V / 18.
V DC voltage signal. In this case, the voltage placement determination circuit 38 may detect this voltage.

Thus, from the head end, the second C
Since the S signal is transmitted as a signal inverted on the frequency axis at a frequency higher than the CS-IF band, demodulation can be performed by the existing tuner at each receiving end simply by inverting the signal to the conventional CS-IF band. Therefore, it is only necessary to install an inverting converter in addition to the existing device at the receiving end. Further, if the polarization plane change signal built in the tuner is used as a switching signal of the inverting converter, the signal transmitted in the conventional CS-IF band is switched and received by the tuner switch operation without interference with the inverted signal. be able to. Although the above embodiment has been described with respect to a case where there are a plurality of CS satellites, the present invention can be similarly applied to a case where there are a plurality of BS satellites. Further, each frequency band and local oscillation frequency are not limited to the above numerical values, but can be changed according to the situation.

[0023]

As described above in detail, according to the first aspect of the present invention, signals of a plurality of satellites can be transmitted to a receiving end by one coaxial cable, and all satellite signals can be transmitted to an existing tuner. Therefore, the apparatus can be inexpensive.

According to the second aspect of the present invention, all CS signals can be received by the existing CS tuner even if the number of CS signals increases.

According to the invention of claim 3, the operation switching of the inverting converter can be operated from the existing tuner, which is convenient.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an example of an embodiment of a satellite broadcast receiving device according to the present invention.

2A and 2B are diagrams showing a frequency spectrum of a signal of the satellite broadcast receiving apparatus of FIG. 1, wherein FIG. 2A shows a distribution of all received satellite signals, and FIG. 2B shows a signal in a coaxial cable in which transmission signals are mixed. And (c) shows an inverted transmission signal that has been inverted by the inverting converter.

FIG. 3 is a block diagram illustrating an internal configuration of the inverting converter of FIG. 1;

FIGS. 4A and 4B are diagrams showing frequency spectra of VHF, UHF, BS-IF, and CS-IF, where FIG. 4A shows the case of Japan and FIG. 4B shows the case of Europe.

[Explanation of symbols]

1. BS antenna, 2 BS converter, 3 C
S antenna, 4 ... orthogonal polarization splitter / demultiplexer, 5a, 5b
・ CS converter, 6 ・ ・ CS antenna, 8a, b ・ ・
CS converter, 9a, 9b block converter,
10. Mixer, 13 Mixer, 19 Inverting converter, 20 Receiver for satellite reception, 22, 23 Coaxial cable, 28, 35 Switching switch.

Claims (3)

[Claims] 1. A method of mixing satellite signals transmitted from a plurality of satellites and receiving signals from a plurality of antennas for receiving satellite signals, respectively.
A satellite broadcast receiving apparatus for transmitting to a receiving end via a coaxial cable, wherein at least one of received satellite signals is provided.
The two satellite signals are once inverted-converted on the frequency axis to an intermediate frequency higher than the second intermediate frequency band, and then mixed. At the receiving end, an inverted converter is provided, and the inverted signal is converted by the inverted converter. Is again inverted into a first intermediate frequency band or a second intermediate frequency band to enable reception by an existing tuner. 2. The inversion-converted signal is a CS signal. At the receiving end, the transmitted CS signal is again inverted and converted into a second intermediate frequency band by an inversion converter, thereby obtaining an existing CS signal. The satellite broadcast receiving device according to claim 1, wherein the tuner demodulates the signal into a signal receivable by a television receiver. 3. The satellite broadcasting according to claim 1, wherein the inverting converter has a changeover switch for passing an input signal without inverting the output signal and outputting the input signal using a polarization plane switching signal of an existing tuner. Receiver.