EP0740434A1 - System for distributing satellite television signals in a community antenna system - Google Patents

Abstract

The invention relates to a system, in particular a common antenna system for distributing television signals from different channels.

The system consists of a signal transmitter device (A), a head device (B) with a signal processing unit (400) and a distribution network (C, 13).

According to the invention, the signal processing device (400) has at least one channel-specific converter (4). Each channel-specific converter (4) converts a specifiable channel in the intermediate frequency band into another channel in the intermediate frequency band. Several channel-specific converters (4) are connected in a chain connection. Channels that are not to be distributed are overlaid by channels that are to be transmitted by amplifying their signal levels.

The processed signals come from different polarities and / or different satellites and are transmitted to user sockets (15) via a single distribution cable (13).

Description

The present invention relates to a system for distributing signals, in particular to a common antenna system for distributing television signals from different channels according to the preamble of claim 1.

Currently two systems are used for this purpose, which are shown schematically in Figures 1 and 2:
In the first system according to the prior art, which is shown in FIG. 1, signals received by the antenna are frequency-demodulated individually for each channel after amplification and conversion by units known per se (low-noise amplifier LNA, low-noise block converter LNB) . The channel-specific frequency-demodulated signals are then amplitude-modulated in a conventional UHF television channel.

This system consists of an antenna 1 which receives television signals of one polarity, a converter 2, in particular an LNA / LNB block, and cables 3 which connect the LNA / LNB block to a signal processing unit 400. This signal processing unit 400 consists of a plurality of channel-specific FM demodulators / AM modulators 19, a switching element 18, a power supply 17, connecting bridges 7, load components 8. Connected to this is a single distribution cable (derivative) 13 with decouplers 14 and user or antenna sockets 15. This system has the disadvantage that it requires a channel-specific FM demodulator / AM modulator 19 for each received satellite channel. Should the If the number of satellite channels to be received is increased, the number of FM demodulators / AM modulators required must also be increased. Each individual FM demodulator / AM modulator, with which both frequency demodulation and amplitude modulation is carried out, is relatively complex in terms of circuitry and is therefore costly. The cost of the system according to FIG. 1 increases considerably if the number of satellite channels to be distributed is increased. Even in relatively small community antenna installations with a small number of users, there are considerable costs with only a few received satellite channels.

Such a system is known for example from EP-A-0 2 888 928, which discloses a device with an internal unit which implements an amplifier and signal converter function. This internal unit has several converters, each with a tuner demodulator and an encoder modulator.

In the second prior art system, which is shown in FIG. 2, television satellite channels are distributed to the system user without the signals being frequency-demodulated and amplitude-modulated beforehand. The signals of the television satellite channels are therefore frequency modulated (for example in the frequency range between 950 MHz and 2050 MHz). In contrast to the system according to FIG. 1, this system according to FIG. 2 does not require any channel-specific FM demodulators / AM modulators connected downstream of the LNA / LNB blocks; However, this system has the disadvantage that more than one distribution cable 13 has to be installed for the distribution of the satellite channels which come from two different polarities or from more than one satellite. The installation of additional distribution cables 13 in existing systems can be very complex or possibly excluded due to the spatial conditions in the buildings in which the additional distribution cables would have to be installed. Furthermore, this system requires the state of the art Technology a plurality of switching devices 16 to select different distribution cables and to tap signals transmitted on the selected distribution cable. The use of these switching devices, which are connected to the distribution cables, is also associated with the risk that electrical switching impulses formed by the switching devices reach the distribution cables and deteriorate the transmission quality of the signals transmitted there.

A method and system for receiving and distributing television signals transmitted by satellites is known from US Pat. No. 5,073,930. This previously known system is structured in such a way that so-called powers splitter are connected downstream of low-noise amplifiers (LNA) and low-noise block converters (LNB), with each transmission line at the output of a low-noise block converter (LNB) 8 transmission lines is split. These transmission lines are routed via a connection bus network to eight satellite transponder processors. The satellite transponder processors each convert signals from one channel to a new frequency position. On the output side, the satellite transponder processors are connected to transponder combination devices. The transponder combination devices then combine the signals formed by the satellite transponder processors. Furthermore, the transponder combination devices have power inserts connected downstream, which are connected on the output side to a plurality of distribution cables. The known system is thus complex in terms of circuitry.

From DE-OS 41 17 208 A1 a device for satellite television reception devices is known, wherein television signals are processed which are received by a parabolic antenna and have horizontally polarized channels and vertically polarized channels. To avoid complex cabling, the horizontally polarized channels and the vertically polarized channels are separated from one another and converted block by block into separate frequency bands. The blocks of channels separated in this way are opened a common line switched. The known device only enables the block-wise implementation of channels. A similarly structured system is also known from European patent application 0 597 783.

Based on this prior art, the object of the invention is to provide a system for distributing signals of the type mentioned at the outset, which enables the distribution of a larger number of channels and is designed in a simple manner in terms of circuitry.

This object is achieved according to the invention by a system according to claim 1.

The system according to the invention has a number of advantages. According to the invention, the user is provided with channels which can be predetermined via only one distribution cable and which are selected individually from signals which originate from one antenna or from several antennas. With the individual selection of channels, the demand of system users with regard to the reception of predefinable channels can be met individually. The channel-specific converters provided according to the invention, which convert a predeterminable channel into another channel, but also the system as a whole, are implemented in a simple manner in terms of circuitry. The channel-specific converters can be set to any frequencies in a predefinable frequency band. The system according to the invention thus enables a changed demand by system users with regard to the reception of predeterminable channels to be met flexibly.

The system according to the invention can be used, inter alia, in those cases in which a single distribution cable has already been laid or in the cases in which the laying of a further distribution cable would be complex or impossible due to the same circumstances.

The system according to the invention, in which channels of two polarities or from two or more satellites are transmitted to user sockets via a single distribution cable, has no switching devices on the distribution cable. This means that no electrical switching impulses are injected onto the distribution cable, so that corresponding interference can be excluded.

An advantageous embodiment of the invention is characterized in that the channel-specific converters of the head device are integrated in at least one converter module, the converter module being connected to downconverters at its input and to the distribution cable at its output. The converter module preferably has at least two converters, the converters in the converter module being connected to one another in a chain connection (an input of a first converter module is connected to the input of a second converter module which is adjacent to the first converter module; an output of the first converter module is connected to the Output of the second converter module connected).

This derailleur structure is characterized by the important advantage in practice that not every channel-specific converter can be connected to a down converter via a separate cable and that, moreover, not every channel-specific converter can be connected to a mixer or adder via a separate cable , which is upstream of the distribution cable. By using the derailleur structure, the separate cables are saved on the one hand and the costs for their installation on the other.

In particular, the channel-specific converters or their inputs and / or their outputs can be connected to one another by means of connecting bridges known per se.

The system according to the invention enables the processing and distribution of signals from a large number of television channels. In this way, several converter modules can be integrated into which a changeable number of channel-specific converters can be integrated, e.g. Connect with each other using a mixer ("9").

The system according to the invention can have a further mixer (“5”) with at least two inputs. One of the inputs is connected to the output of a converter module, while another input is connected directly to a down converter of an antenna. This mixer, which may be connected to the distribution cable on the output side via an amplifier, makes it possible to couple additional channels into the distribution cable, namely of first channels or signals that are emitted by satellites and received by parabolic antennas, as well as of second channels or Signals transmitted by terrestrial transmitters and received by conventional antennas, as well as by first and second signals.

The channel-specific converters can each have a microprocessor that controls at least one oscillator. The microprocessor makes it possible to releasably connect an input device external to the converter to the microprocessor and to input data into the converter or the microprocessor which designate a predefinable input channel frequency and a predefinable output channel frequency. In this way, the channel-specific converters can be set in a particularly simple manner to a predefinable input frequency and to a predefinable output frequency, by means of which the frequency conversion of a channel is determined. The input device external to the converter can also be designed as a remote control transmitter.

It is further provided according to the invention that the channel-specific converter has an amplifier with controllable gain, one Mixer ("5") with at least two inputs fed signals of different channels of the same frequency with different signal levels. Different channels can thus be easily overlaid on the distribution cable. With the signal level difference of at least 15 dB provided according to the invention, the superimposed channels can be represented in good reception quality in the terminals that can be connected to the user sockets.

The illustrated properties of the invention as well as further properties and advantages will now be described with reference to the drawings, in which exemplary embodiments of the invention are shown.

Fig. 1 und 2

Signalverteilsysteme nach dem Stand der Technik;

Fig. 3

ein erstes Ausführungsbeispiel des Signalverteilsystems gemäß der Erfindung;

Fig. 4 - 6

Ausführungsbeispiele von Signalverarbeitungseinheiten eines erfindungsgemäßen Signalverteilsystems nach Figur 3;

Fig. 7

ein Ausführungsbeispiel eines kanalindividuellen Konverters in einer Signalverarbeitungseinheit nach den Figuren 3 - 6;

Fig. 8

ein Ausführungsbeispiel eines Mischers, der in einer Signalverarbeitungseinheit nach den Figuren 3 - 6 mindestens einem kanalindividuellen Konverter nachgeschaltet ist;

Fig. 9

ein Ausführungsbeispiel eines erfindungsgemäßen Signalverteilsystems mit ausgewählten Schaltungspunkten, und

Figur 10

Diagramme von Kanalsignalfrequenzen an den Schaltungspunkten des erfindungsgemäßen Signalverteilsystems nach Figur 9.

It shows:

1 and 2

Signal distribution systems according to the prior art;

Fig. 3

a first embodiment of the signal distribution system according to the invention;

4 - 6

Embodiments of signal processing units of a signal distribution system according to the invention according to Figure 3;

Fig. 7

an embodiment of a channel-specific converter in a signal processing unit according to Figures 3-6;

Fig. 8

an embodiment of a mixer, which is connected in a signal processing unit according to Figures 3-6 at least one channel-specific converter;

Fig. 9

an embodiment of a signal distribution system according to the invention with selected circuit points, and

Figure 10

Diagrams of channel signal frequencies at the circuit points of the signal distribution system according to the invention according to FIG. 9.

The signal distribution system shown in the drawings, as also shown in FIG. 3, consists of three blocks A, B and C. Block A is a signal transmitter device, block B is a head device with a signal processing unit and block C represents the distribution network.

• 1. Block A ist eine Signalgebereinrichtung, die aus mindestens einer Antenne 1 sowie aus bekannten Abwärtsumsetzern 2 (low-noise amplifier LNA, low-noise block converter LNB) besteht. Die empfangenen Signale können von verschiedenen Rundfunk- und/oder Fernmeldesatelliten stammen und/oder verschiedene Polaritäten (horizontal, vertikal) aufweisen. Die Abwärtsumsetzer 2 setzen die empfangenen Signale in an sich bekannter Weise aus dem Empfangsfrequenzbereich von z.B. 11,7 - 12,5 GHz; 10,7 - 11,7 GHz; 12,5 - 12,75 GHz oder vorzugsweise 10,7 - 12,5 GHz in einen Zwischenfrequenzbereich von z.B. 950 - 1760 MHz oder vorzugsweise 950 MHz und 2050 MHz um;
• 2. Block B ist eine Kopfeinrichtung mit einer Signalverarbeitungseinrichtung 400, in der kanalindividuelle Konverter 4 angeordnet sind. Die kanalindividuellen Konverter 4 werden noch detailliert insbesondere anhand von Figur 7 beschrieben. Verschiedene Ausgestaltungen der Signalverarbeitungseinrichtung 400 sind in den Figuren 3, 4, 5 und 6 dargestellt;
• 3. Das Verteilungsnetz C weist ein einziges Verteilkabel 13 auf, über das die Signale über Abgreif- bzw. Ableiteinrichtungen 14 bis zu Benutzersteckdosen 15 übertragen werden.

Blocks A, B and C are designed as follows:

• 1. Block A is a signal transmitter device, which consists of at least one antenna 1 and known down-converter 2 (low-noise amplifier LNA, low-noise block converter LNB). The received signals can originate from different radio and / or telecommunications satellites and / or have different polarities (horizontal, vertical). The downconverters 2 set the received signals in a manner known per se from the reception frequency range of, for example, 11.7-12.5 GHz; 10.7-11.7 GHz; 12.5 - 12.75 GHz or preferably 10.7 - 12.5 GHz in an intermediate frequency range of, for example, 950 - 1760 MHz or preferably 950 MHz and 2050 MHz;
• 2. Block B is a head device with a signal processing device 400, in which channel-specific converters 4 are arranged. The channel-specific converters 4 are described in detail, in particular with reference to FIG. 7. Different configurations of the signal processing device 400 are shown in FIGS. 3, 4, 5 and 6;
• 3. The distribution network C has a single distribution cable 13, via which the signals are transmitted via tapping or derivation devices 14 to user sockets 15.

Block A of the system according to the invention, that is to say the signaling device, as shown, for example, in FIG. 3, consists of antennas 1 which receive the signals from television channels which are transmitted via satellites. If the antennas are parabolic antennas, the focus is on each an antenna 1 is arranged a down converter 2 which converts the received signals in a manner known per se from the satellite television reception frequency range from, for example, 10.7 to 12.5 GHz to the intermediate frequency range between 950 MHz and 2050 MHz (usually as "first intermediate frequency" designated) implement. Such downconverters 2 with an amplifier LNA and a channel block converter LNB are known and available on the market.

Each antenna 1 has one or two downconverters 2 (or a downconverter with two outputs) depending on whether signals of one or two polarities (horizontal, vertical) are to be received per antenna. If the antenna 1 receives signals of one polarity, a down converter 2 is provided; if the antenna 1 receives signals of two polarities, two downconverters 2 are provided.

The downconverters 2 are each connected to a cable 3 on the output side. In different embodiments of the invention, one or more cables 3, as shown in FIGS. 3, 4, 5, 6 and 9, lead to the signal processing unit 400 with at least one channel-specific converter 4. It can also be provided that one or more cables 3 As shown in FIGS. 3, 6 and 9, lead to a ("second") mixer 5, which is connected downstream of a channel-specific converter 4 or a converter module 40 with at least one channel-specific converter 4.

The channel-specific converters 4 of the head device B are preferably integrated in at least one converter module 40, the converter module 40 being connectable to a down converter (LNA / LNB) 2 at its input via a cable 3 and to the distribution cable 13 (coaxial cable) at its output. The distribution cable 13 is preferably connected to the output of an amplifier 6, which can be connected downstream of the (“second”) mixer 5.

Each channel-specific converter 4, the circuit structure of which is explained in detail with reference to FIG. 7, has two inputs and two outputs.

As shown in FIGS. 3, 4, 5, 6 and 9, the channel-specific converters 4 of a converter module 40 are connected to one another in such a way that an input (eg EC1 in FIG. 7) of a first converter module with the input (eg EC2) of one second converter module (not shown in FIG. 7), which is adjacent to the first converter module. An output (e.g. SC1) of the first converter module is also connected to the output (e.g. SC2) of the second converter module (chain connection).

This derailleur structure is distinguished by the practically important advantage that not every channel-specific converter 4 is to be connected to a down converter 2 via a separate cable 3 and, moreover, that not every channel-specific converter 4 is connected to a ("second") via a separate cable To connect mixer (5), which is upstream of the distribution cable 13.

It can be provided that each of the two inputs is connected, for example via a known connecting bridge 7, to an input of an upstream channel-specific converter 4 or to the input of a downstream channel-specific converter 4. It can also be provided with regard to the outputs that each of the two outputs is in each case, for example via a known connecting bridge 7, with an output of an upstream channel-specific converter 4 or with the output of a downstream channel-specific converter 4. An identical housing is preferably provided for each channel-specific converter 4, that is to say a housing of the same spatial dimensions, on which the input and output connections are arranged at the same locations. This enables the use of identical connecting bridges 7, with which either an electrical connection between two inputs or between two outputs are made.

Furthermore, it can be provided that an input of a converter 4 (first converter 4 of a converter module 40, which is shown in FIGS. 4 and 5 on the right in a converter module) with a cable 3, which the generated by the down converter 2 or in the intermediate frequency range transmits converted signals, is connected. An input of a converter 4 (last converter 4 of a converter module 40, which is shown on the left in FIGS. 4 and 5) is connected to a feed source 11 which supplies the converters 4 and an amplifier 12 provided for each signal processing unit 400.

On the input side, these channel-specific converters 4 receive the signals or channels in the intermediate frequency range, which are output by the downconverters 2 and transmitted via the cables 3, and convert the signals or channels in the intermediate frequency range, as will be described with reference to FIGS. 9 and 10.

Inputs of the channel-specific converters 4, which are not connected to the input of an adjacent converter or to which no cable 3 is connected, can be terminated with an ohmic resistor 8 of 75 ohms (cf. FIG. 3, block B, reference number 8 above the converter 4; right converter module 40 in FIG. 5; FIG. 9, reference number 8 above the converter 4).

Likewise, outputs of the channel-specific converters 4 can be terminated with an ohmic resistance 8 of 75 ohms (cf. FIG. 3, block B, reference number 8 below the converter 4; right and left converter module 40 in FIG. 5; FIGS. 6 and 9, reference number 8 below the converter 4). These are in particular the output of a (in terms of signal flow) first converter 4 in a first converter module (right Converter module in Figure 5) and the output of a (in terms of signal flow) last converter 4 in a last converter module (left converter module in Figure 5).

With each channel-specific converter 4, a channel is selected and converted from an input frequency in the intermediate frequency range to a predefinable output frequency in the intermediate frequency range.

As already described, a plurality of channel-specific converters 4, at least two, preferably four converters 4 can be integrated in one converter module 40. Two adjacent modules can be combined with one another via a (“first”) mixer 9.

The output of the first mixer 9 is introduced into the arrangement of the feed source 11 and amplifier 12 by means of a connecting cable 10. The amplified signal is fed to the second mixer 5.

The channel-specific converter 4 is preferably configured as follows:

Input side

Frequency range: 950 ... 1950 (or 2050) MHz Input level: - 50 ... -30 dBm Mirror selection (image frequency rejection): ≧ 40 dB Intermediate frequency: 479.5 MHz Bandwidth: 27 MHz Loop input losses: <1.2 dB

Output side

Frequency range: 950 ... 1950 (or 2050) MHz Max. Output level: - 25 ± 5 dBm Output level control range: 15 dB Bandwidth: 27 MHz Loop-through output losses: <1.2 dB Noise level: > - 20 dBc

The feed source 11 is preferably configured as follows: Mains voltage: 230V ± 15% Output voltage: 15V / 5V Intermediate frequency loop-through losses: <1.2 dB

The amplifier 12 is preferably configured as follows: Bandwidth: 950 ... 2050 MHz Profit: 23 ... 33 dB Max. Output level for two channels: 115 dBµV / 6 dBm

The first mixer 9 is preferably configured as follows: Bandwidth: 950 ... 2050 MHz Insertion loss: <4 dB Rejection between inputs: 15 dB

As shown in FIG. 6, first signals, which form a converter module 40 (input E1), second signals, which are formed by the downconverters 2 (input E2), and third signals, which are emitted by antennas, can be the signals terrestrial transmitter received, the second mixer 5 are fed. The distribution cable 13 is connected on the output side to this mixer 5. Alternatively, it is provided that the mixer 5 is followed by an amplifier 6 to which the distribution cable 13 is connected on the output side.

As shown in Fig. 3, the distribution network C consists of a single distribution cable 13 on which all channels that are FM-modulated are transmitted. The distribution cable 13 is formed and leads by a coaxial cable to derivation devices 14, which couple the signal to different user sockets 15.

FIG. 4 shows a signal processing unit 400 with a converter module 400, which consists of four channel-specific converters 4, while FIG. 5 shows a signal processing unit 400 with two converter modules 400, each consisting of four channel-specific converters 4.

In the system according to the invention, the number of channel-specific converters 4 is equal to the number of channels which are coupled into the distribution cable 13 and transmitted to the user sockets 15 via the diverters 14. The channel-specific converters can be set to predefinable input frequencies in the intermediate frequency range and to predefinable output frequencies in the intermediate frequency range.

An exemplary embodiment of a channel-specific converter 4 is shown in FIG. Two inputs EC1 and EC2 are electrically connected to one another and via a directional coupler 41 to and an amplifier 42. The inputs EC1 and EC2 are designed mechanically in such a way that known connecting bridges (7 in FIG. 4) can be used for connection to an input of an adjacent channel-specific converter. In this way, several channel-specific converters can be integrated into one converter module.
This form of connection therefore consists in that each of the two inputs EC1, EC2 is connected, for example in each case via a known connecting bridge, to an input of an upstream channel-specific converter 4 or to the input of a downstream channel-specific converter 4. Likewise, each of the two outputs SC1, SC2 of the converter 4 is connected, for example in each case via a known connecting bridge, to an output of an upstream channel-specific converter 4 or to the output of a downstream channel-specific converter 4. This form of connection has the advantage that distribution devices, which would otherwise have to be connected downstream of the downconverters 2, and connecting cables between these distribution devices and channel-specific converters are not required.

The amplifier 42 amplifies the supplied signals e.g. in the frequency band from 950 to 2050 MHz. The signals are fed to a tracking filter 43 on the input side. This filter is a bandpass filter that is tuned to the selected input channel frequency using a voltage formed by a phase locked loop (PLL) circuit 46. The circuit 46 is controlled by a microprocessor (MP) 49.

A mixer 44 connected downstream of the lag filter 43 is controlled by a local oscillator (OL) 45, which in turn is controlled by the PLL circuit 46. The mixer 44 converts the frequency of the selected channel present at the inputs EC1 and EC2 to a frequency of 479.5 MHz.

The signal formed by the mixer 44 is fed to a low-pass filter 47, the cut-off frequency of which is, for example, 600 MHz. This eliminates the signal from the local oscillator 45 and unwanted signals formed during the mixing process.

The signal is then filtered using a SAW 50 surface acoustic wave filter, e.g. has a bandwidth of 27 MHz at a center frequency of 479.5 MHz. The amplifiers 48 and 51 connected upstream or downstream of the surface acoustic wave filter SAW increase the signal level so that the losses caused by the SAW filter 50 are compensated for.

The mixer 52 connected downstream of the amplifier 51 mixes the signal of the signal of the frequency 479.5 MHz selected at the input with a signal which is formed by a local oscillator (OL) 53. The local one Oscillator is controlled by a PLL circuit 54. The PLL circuit 54 is also controlled by the microprocessor 49. The mixer 52 is followed by an output-side tracking filter 55 which, like the filter 43, is a bandpass filter. The filter 55 eliminates the unwanted signals generated by the mixing performed by the mixer 52. The signal of the frequency-converted channel is then present at the output of the filter 55 and is fed to an amplifier 56.

The gain of the amplifier 56 can be controlled, so that the level of the frequency-converted channel signal can be set to predeterminable values (see e.g. channels 1 and 5 in FIG. 8).

A downstream directional coupler 57 couples the amplified signal to the outputs SC1, SC2. The outputs SC1 and SC2 are designed mechanically in such a way that known connecting bridges (7 in FIG. 4) can be used for connection to an output of an adjacent channel-specific converter.

As shown in FIG. 7, the converters 4 can have a microprocessor 49 which controls the PLL circuits 46 and 54 and determines the input and output frequency of the channel signal of the converters 4. Furthermore, the microprocessor 49 can control the amplifier 56. The microprocessor 49 can e.g. An input unit 16 can be connected via a 4-cable bus, via which the data of a specifiable input and output frequency and / or control data for the amplifier 56 (signal amplification parameters) can be input into the microprocessor 49.

The input unit 16 can have a control unit 162 (in particular a microprocessor MP), a program associated with the control unit 162 forming data, for example, as a function of the cutoff frequencies of the respective intermediate frequency range (950 MHz, 2050 MHz), channel bandwidths and channel spacings and signal levels of the channel signals, the given correspond to technical specifications and which are input into the microprocessor 49 of the channel-specific converter 4. The input unit 16 contains a keyboard 161, the control unit 162 and a display 163. The display shows data entered into the keyboard 161, operator guidance information, and information which indicate the state of the converter after it has been set by the input data. The input unit 16 can be designed as a remote control transmitter with a transmitting device that transmits the data to be entered to a receiving device that is connected to the microprocessor 49 of the channel-specific converter.

FIG. 8 shows a second mixer 5, which is also shown in FIG. 3, block B. The second mixer 5 has e.g. three inputs E1, E2, E3 and an output S to which the distribution cable 13 is connected. The distribution cable 13 is preferably a coaxial cable, but an optical fiber can also be provided.

The input E1 is connected directly to one or more converter modules 40 via a cable; a cable 3 with a down converter (2 in FIG. 3) is connected directly to the input E2, while the input E3 is connected to a system for receiving terrestrial channels.

As is shown by way of example in FIG. 8, signals of channels 1, 2, 3, 4, 5 and 6, which originate from a satellite and have a bandwidth of 27 MHz, and, as described, from channel-specific converters in Frequency band between 950 and 2050 MHz were implemented.
Signals of channels 7, 8, 9, 10, 11, 12, 13 and 14, which originate from a satellite, have a bandwidth of 27 MHz and, as described, from channel-specific converters in the frequency band between 950 and 2050 are fed to input E2 MHz were implemented.

At the input E3 there are 6 terrestrial television channels with an 8 MHz bandwidth in the frequency band between 47 and 860 MHz.

The signals of the channels that are present at the input E1 are supplied by the channel-specific converters 4, in which the frequency conversion and the formation of the respective levels takes place with regard to the coupling of the signals via the mixer output S into the distribution cable 13.

The channels 2, 4 and 6, which are pending at the input E1, have been converted in frequency in the channel-specific converters 4 in such a way that no channels of the same frequencies are pending at the input E2. Channels 1 and 3 at input E1 are arranged in frequencies between the undesired channels 7 and 8 or 9 and 10, which are present at input E2. The signal or power level of channel 1 is set to a value of at least 15 dB above the corresponding level of channels 7 and 8; and the signal or power level of channel 3 is set to a value of at least 15 dB above the corresponding level of channels 9 and 10.

The channel 5 of the input E1 is arranged at the same frequency as the unwanted channel 12 which is present at the input E2, the signal or power level of the channel 5 being at least 20 dB above the corresponding level of the channel 12.

• im Frequenzband zwischen 47 und 860 MHz sind am Ausgang S dieselben Kanäle in derselben Frequenzposition und mit denselben Pegeln vorhanden wie am Eingang E3;
• im Frequenzband zwischen 950 und 2050 MHz werden am Ausgang S die Kanäle 7 und 8 des Eingangs E2 vom Kanal 1 des Eingangs E1 überlagert. Da der Kanal 1 auf einen Signalpegel gesetzt ist, der wenigstens 15 dB oberhalb der Pegel der Kanäle 7 und 8 liegt, ist für den Systembenutzer nur Kanal 1 sichtbar, ohne daß die Kanäle 7 und 8 Störungen erzeugen.
  Ebenso werden am Ausgang S die Kanäle 9 und 10 des Eingangs E2 vom Kanal 3 des Eingangs E1 überlagert.
  Außerdem ist in das Verteilkabel 13 am Ausgang S der Kanal 5 des Eingangs E1 in der Frequenzposition des Kanals 12 des Eingangs E2 eingekoppelt, wobei Kanal 5 den Kanal 12 überlagert, da der Signalpegel von Kanal 5 mindestens 20 dB oberhalb des Kanals 12 liegt.
  Außerdem sind in das Verteilkabel 13 der Kanal 4 (ursprünglich am Eingang E1) zwischen die Kanäle 3 (ursprünglich am Eingang E1) und 11 (ursprünglich am Eingang E2) eingekoppelt und der Kanal 6 (ursprünglich am Eingang E1) ist zwischen die Kanäle 13 (ursprünglich am Eingang E2) und 14 (ursprünglich am Eingang E2) eingekoppelt. Die Kanäle 4 und 6 werden also frequenzmäßig in am Eingang E2 freie Frequenzpositionen eingefügt.

The level difference (at least 15 dB or at least 20 dB) depends on the frequencies of the overlaying channel and the frequency of the channel or channels to be overlaid: if the frequency is different (see channel 1, which overlaps channels 7 and 8), the level difference is at least 15 dB; at the same frequency (see channel 5, channel 12 superimposed) the level difference is at least 20 dB.
The channels designed in this way with regard to frequency and level at the inputs E1, E2 and E3 of the mixer 5 are by the Mixer coupled at the output S into the distribution cable 13 in the arrangement shown in FIG. 8:

• in the frequency band between 47 and 860 MHz, the same channels are present at the output S in the same frequency position and at the same levels as at the input E3;
• In the frequency band between 950 and 2050 MHz, channels 7 and 8 of input E2 are superimposed on channel S of input E1 at output S. Since channel 1 is set to a signal level that is at least 15 dB above the level of channels 7 and 8, only channel 1 is visible to the system user without channels 7 and 8 generating interference.
  Likewise, channels 9 and 10 of input E2 are superimposed on channel S of input E1 at output S.
  In addition, channel 5 of input E1 is coupled into the distribution cable 13 at output S in the frequency position of channel 12 of input E2, channel 5 being superimposed on channel 12 since the signal level of channel 5 is at least 20 dB above channel 12.
  In addition, channel 4 (originally at input E1) is coupled into distribution cable 13 between channels 3 (originally at input E1) and 11 (originally at input E2) and channel 6 (originally at input E1) is between channels 13 ( originally coupled in at input E2) and 14 (originally at input E2). Channels 4 and 6 are thus inserted in frequency into free frequency positions at input E2.

Overall, the channels in the frequency band from 47 to 860 MHz and channels 1, 2, 3, 4, 11, 5, 13, 6 and 14 in the frequency band from 950 to 2050 MHz are made available to the system user. Channels 7, 8, 9, 10 and 12 are also transmitted on the distribution cable 13; however, these are overlaid so that they are not made available to the system user. With the signal level difference of at least 15 dB provided according to the invention, the overlapping channels can be shown in display the devices that can be connected to the user sockets in good reception quality.

FIG. 9 shows an exemplary embodiment of the system according to the invention, which is also shown in FIG. 3. It is assumed that signals from different television channels are received and processed, which come from three satellites of different orbital positions with horizontal and vertical positions. In the system according to the invention shown in FIG. 9, circuit points d, e, f, g, h, i, j, k, l, m, n, and o are specified.

FIG. 10 shows the channels at the circuit points d - o shown in FIG. 9.

At points d, e and f of FIG. 9 are the signals which are received by each satellite in a frequency band between 10.7 and 12.5 GHz with horizontal and vertical polarity.

As shown in FIG. 10, the channels 70, 72, ..., 92 are in vertical polarity and the channels 71, 93, ..., 93 are in horizontal polarity at the switching point d (parabolic antenna on the left in FIG. 9) . At circuit point e (central parabolic antenna in FIG. 9), channels 65,... 69 are in only one polarity. At circuit point f (parabolic antenna on the right in FIG. 9), channels 49, 51, ... 63; 33, 35, ... 47; 1, 3, ... 31 in vertical polarity and channels 50, 52, ... 64; 34, 36, ... 48; 2, 4, ..., 32 in horizontal polarity.

Each down converter 2 (FIG. 9) selects a polarity and converts the frequency band from 10.9 to 12.5 GHz into the frequency band from 950 to 2050 MHz in such a way that in each cable 3 at the switching points g, h, i, j, k the channels are present that belong to the same satellites and to the same polarity.

As shown in FIG. 10, channels 70, 72,... 92 are present at node g, channels 71, 73,... 93 at node h, channels 65-69 at node i, at node j channels 49, 51 ... 63, 33 .... 47, 1, 3, ... 31 and at circuit point k channels 50, 52 ... 64; 34, 36, ... 48; 2, 4 ... 32.

Desired channels are selected from all available channels at the switching points d - k. For example, the channels 60, 36, 44, 2, 6, 12, 18 and 24 present at the circuit point k are no longer processed, while the channels 65, 72, 68 present at the circuit points g, h, i, j , 82, 77, 17, 89 and 41 are processed further.

For this purpose, converter modules 40 are provided at the circuit points g, h, i, j, the channel-specific converters 4 of the modules 40 being set to the input frequencies of each of the selected channels and to the output frequencies to which the channels are to be arranged. These output frequencies are occupied frequencies of unwanted channels to be superimposed or free frequencies.

According to the invention, channels are provided at the output of each converter module 40 which have a different frequency position compared to the frequency position at the input of the modules.

As can be seen from FIG. 10, the channels 72, 82, 77 and 89 occur at the circuit point i in a frequency position which differs from the frequency position of the channels at the circuit points g and h. At node m, there are channels 65, 68, 17 and 41, which originate from nodes i and j, also in different frequency positions. After the channels have been subjected to a mixing process in the mixer 9, all selected channels are present at the switching point n, as shown in FIG. 10, that of the switching points g, h, i and j originate in frequency positions that differ from the original frequency positions. These channels are introduced via the feed source 11 into the amplifier 12, which amplifies the signal levels of the channels. Thereafter, in the mixer 5, the channels which are at the node n are mixed with the channels which are at the node k. In this mixing process, the channels that are at node n are superimposed on the channels of the same frequency that are at node k.

The channels at node n have a higher signal level of at least 15, but preferably 18 to 20 dB above the signal levels of the channels at node k that are to be superimposed. This level difference ensures that the channel that is superimposed on another channel is received without interference from the channel that has been superimposed.

After the mixing process has been carried out in the second mixer 5, one or more channels are obtained, which are shown in FIG. 10, these channels then being distributed over the single distribution cable 13. In this case, as is shown by way of example in FIG. 10, the channel 65 is superimposed on the channel 60 (cf. larger amplitude of 65 compared to 60), the channel 72 on the channel 36, the channel 68 on the channel 44, the channel 82 channel 2, channel 77 channel 6, channel 17 channel 12, channel 89 channel 18 and channel 41 channel 24.

According to the invention, it is therefore provided that signals, in particular television signals from different channels transmitted via satellites, are distributed in a common antenna system. The signals are received in a signal transmitter device A and the received signals of a certain polarity (H, V) are converted from a reception frequency band into signals in an intermediate frequency band. The signals converted into the intermediate frequency band are processed and the processed signals are transmitted to user sockets 15 in the intermediate frequency band via a single distribution cable 13. Individual channels that can be specified in the intermediate frequency band are converted into other channels in the intermediate frequency band.

First channels implemented in the intermediate frequency band are mixed with second channels in the intermediate frequency band and the first and second channels are transmitted via the distribution cable 13. In particular, different signal levels are formed for two channels of the same frequency converted into the intermediate frequency band, the signal levels of the signals of different channels differing by at least 15 dB.

Reference list

A

Signaling device

B

Head device

C.

Distribution network

EC1, EC2

Inputs of 4

SC1, SC2

Outputs from 4

OIL

local oscillator 45, 53 (in 4)

1

antenna

2nd

Down converter LNA / LNB

3rd

electric wire

4th

channel-specific converter

41, 57

Directional coupler

42

amplifier

43, 55

Follow-up filter

44, 52

mixer

45, 53

local oscillator OL

46, 54

PLL circuit

47

Low pass

48, 51

amplifier

49

microprocessor

50

SAW filter

40

Converter module

400

Signal processing device

5

second mixer

6

amplifier

7

Connecting bridge

8th

load

9

first mixer

10th

connection cable

11

Food source

12th

amplifier

13

Distribution cable (derivation)

14

Drainage devices

15

User sockets

16

Input unit

161

keyboard

162

Control unit

163

Display

Claims (15)

System for the distribution of signals, in particular common antenna system for the distribution of television signals of different channels, which are transmitted in particular via satellites, the system comprising - A signaling device (A) with at least one antenna (1), which receives the signals, and at least one down converter (LNA / LNB 2), which converts received signals of a certain polarity (H, V) from a reception frequency band into signals in an intermediate frequency band , - A head device (B) which is connected downstream of the signal transmitter device (A) and which has at least one signal processing unit (400) which is connected on the input side via a cable (3) to the down converter (LNA / LNB 2) and on the output side with a single one Distribution cable (13) can be connected, via which the processed signals are transmitted in the intermediate frequency band to user sockets (15),
characterized by
that the signal processing unit (400) of the head device (B) has at least one channel-specific converter (4), and that it converts channel-specific converters (4) a predefinable channel in the intermediate frequency band into another channel in the intermediate frequency band. System according to claim 1, characterized in that channel-specific converters (4) of the head device (B) are integrated in at least one converter module (40), and in that the converter module (40) its input via the cable (3) with the downconverters (LNA / LNB 2) and at its output with the distribution cable (13) can be connected. System according to Claim 2, characterized in that the converter module (40) has at least two channel-specific converters (4), and in that the channel-specific converters (4) in the converter module (40) are connected to one another in such a way that an input (EC1) a first converter module is connected to an input (EC2) of a second converter module which is adjacent to the first converter module, and that an output (SC1) of the first converter module is connected to an output (SC2) of the second converter module. System according to claim 3, characterized in that the connection of the inputs of two adjacent channel-specific converters (4) and / or the connection of the outputs of two adjacent channel-specific converters (4) is realized by connecting bridges (7). System according to one of the preceding claims, characterized in that the channel-specific converter (4) has a tracking filter (43, 55) on the input side and / or on the output side. System according to one of the preceding claims, characterized in that the channel-specific converter (4) has a microprocessor (49) which has at least one oscillator (45, 53) of the channel-specific converter (4) and / or an amplifier (56) of the channel-specific converter (4) controls. System according to Claim 6, characterized in that the microprocessor (49) of the channel-specific converter (4) can be connected to an input device (16) external to the converter, via which data can be input which indicate a predefinable input channel frequency and a predeterminable output channel frequency and / or signal amplification parameters for controlling the amplifier (56). System according to one of the preceding claims, characterized in that the input device (16) external to the converter has a control unit (162). System according to one of claims 2 to 8, characterized in that several converter modules (40) are connected to a first mixer (9), the output of which can be connected to the distribution cable (13) via a power supply source (11). System according to one of the preceding claims, characterized in that the system has a second mixer (5) with at least two inputs (E1, E2, E3), that one of the inputs (E1) can be connected to the output of the converter module (40), that a further input (E2, E3) can be connected to a down converter (LNA / LNB 2) and that the second mixer (5) has an output (S) with which the distribution cable (13) can be connected. System according to claim 10, characterized in that signals of different channels of the same frequency in the intermediate frequency band which are fed to different inputs (E1, E2, E3) of the second mixer (5) have different signal levels. System according to claim 10, characterized in that the signal levels of the signals of different channels differ by at least 15 Db. System according to one of claims 2-12, characterized in that the distribution cable (13) can be connected to the output of an amplifier (6) whose input can be connected to the output of a channel-specific converter (4) or a converter module (40). Channel-specific converter (4) for use in a system according to one of the preceding claims. Input device (16) for use with a channel-specific converter (4) according to claim 14.

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