EP0740434B2 - System for distributing satellite television signals in a community antenna system - Google Patents

Description

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

At present, essentially two systems are used for this purpose, which are shown schematically in FIGS. 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 channel-individually after amplification and conversion by units known per se (low-noise amplifier LNA) , Subsequently, the channel-specific frequency demodulated signals are 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 a single distribution cable (lead) 13 with Auskopplern 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. If the number of satellite channels to be received is to be increased, the number of necessary FM demodulators / AM modulators must also be increased. Each individual FM demodulator / AM modulator, with which both the frequency demodulation and the amplitude modulator is carried out, is relatively complicated in terms of circuitry and therefore expensive. The cost of the system of Figure 1 increases significantly as 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 already considerable costs for a few received satellite channels.

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

Such a system is further known from DE-A-40 12 657, wherein in the system converters each having a tunable demodulator and an AM modulator are provided.

In the second prior art system shown in Figure 2, the distribution of television satellite channels to the system user is accomplished without the signals being previously frequency demodulated and amplitude modulated. Such a system is known from U.S. Patent 4,608,710. The signals of the television satellite channels are thus distributed in a frequency modulated manner (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 channels of individual 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 originating from two different polarities or from more than one satellite. The installation of additional distribution cable 13 can be very expensive or possibly excluded in existing systems due to spatial conditions in the buildings where the additional distribution cables would be installed. Further, this prior art system requires multiple switching devices 16 to select different distribution cables and to pick up 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 come from the switching devices formed electrical switching pulses on the distribution cables and deteriorate the transmission quality of the signals transmitted there.

From DE-OS 41 17 208 A1 a device for satellite television receiving devices is known, wherein television signals are processed, which are received by a satellite dish and horizontally polarized channels and

having vertically polarized channels. To avoid cumbersome wiring, the horizontally polarized channels and the vertically polarized channels are separated from each other and converted block by block into separate frequency bands. The thus separated blocks of channels are switched to a common line. The known device only allows the blockwise implementation of channels. Similarly structured systems are also known from European Patent Application 0 597 783 and from DE-U-93 06 499.

From U.S. Patent 5,073,930 a method and system for receiving and distributing television signals transmitted by satellites is known. This prior art system is structured in such a way that low-noise amplifiers (LNA) and low-noise block converters (LNB) are connected downstream so-called power splitter, each transmission line at the output of a low-noise block converter (LNB) in 8 transmission lines is split. These transmission lines are routed via a link bus network to eight satellite transponder processors. The satellite transponder processors each convert signals of a channel into a new frequency position. On the output side, the satellite transponder processors are connected to transponder combination devices. The transponder combination devices then carry those from the satellite transponder processors formed signals zwammen ("frequency mapping"). The signals are arranged as if they had been transmitted directly from the system's antennas to this node. Furthermore, the transponder combination devices power inserter are connected downstream, which are connected on the output side with several distribution cables. The known system is thus designed circuit complex.

Based on this prior art, the present invention seeks to provide a system for distributing signals of the type mentioned above, which allows the distribution of a larger number of channels and circuitry is designed in a simple manner, and a corresponding channel-individual converter

This object is achieved by a system according to claim 1 and a channel-individual converter according to claim 14.

The system according to the invention is characterized by a plurality of vortexes. According to the invention, the user is provided with prescribable channels via only one distribution cable, which channels are selected individually from signals originating from one antenna or from a plurality of 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 converter provided according to the invention, which convert a predeterminable channel into another channel, but also the system as a whole, are realized in a simple manner in terms of circuit technology. The channel-specific converters can be set to any frequency in a predefinable frequency band. Individual signals or channels can be superimposed by other signals or channels, with both the 1 superimposed and the superimposed signals are transmitted to the user. Usable for the user, however, are only the overlapping signals. Thus, the erfindungagemäße system that a changed demand of system users with regard to the use of predeterminable channels can be flexibly met.

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

Also, the system according to the invention, in which channels of two polarities or of two or more satellites are transmitted to user sockets via a single distribution cable, has no switching devices on the distribution cable. Thus, no electrical switching pulses are coupled to the distribution cable, so that corresponding disturbances are excluded.

An advantageous embodiment of the invention is characterized in that the channel-specific converter of the head device are integrated in at least one converter module, wherein the converter module is connected at its input with down converters and at its output to the distribution cable. Preferably, the converter module has at least two converters, wherein the converters in the converter module are connected to one another in 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 first converter module Output of the second converter module connected).

This chain circuit structure is characterized by the in practice important advantage that not every channel-specific converter is to be connected via a separate cable with a down converter and that, moreover, not every channel-specific converter is to be connected via a separate cable with a mixer or adder , which is upstream of the distribution cable. The use of the derailleur structure saves both the separate cables and the cost of installing them. In particular, the channel-specific converter or its 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 of a plurality of television channels. Thus, several converter modules, in which a variable number of channel-specific converters can be integrated. e.g. connect via a mixer ('9').

The system according to the invention may comprise a further mixer ("5") with at least two inputs. In this case, 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, the output side may be connected via an amplifier with the distribution cable, makes it possible to couple more channels in the distribution cable, and although from first channels or signals that are emitted by satellites and received by satellite dishes. as well as second channels or signals emitted by terrestrial transmitters and received by conventional antennas, as well as first and second signals.

The channel individual converters may each comprise a microprocessor which controls at least one oscillator. The microprocessor makes it possible to detachably connect a converter-read input device 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-independent converter can be adjusted in a particularly simple manner to a predefinable input frequency and to a predefinable output frequency, by which the frequency conversion of a channel is determined. The external converter input device can also be configured as a remote control transmitter.

The channel-specific converter have an amplifier with controllable gain, wherein a mixer ("5") with at least two inputs signals of different channels of the same frequency are supplied with different signal levels. This makes it easy to superimpose different channels on the distribution cable. In the case of the signal level difference of at least 15 dB provided according to the invention, the overlapping channels in the terminals which can be connected to the user sockets can be represented in good reception quality.

The illustrated features of the invention as well as other features and advantages will now be described with reference to the drawings, in which 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:

Fig. 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;

Fig. 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 downstream of at least one channel-individual converter in a signal processing unit according to Figures 3-6;

Fig. 9

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

FIG. 10

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

• 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.

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 signaling device, block B is a header device with a signal processing unit and block C represents the distribution network. The blocks A, B and C are configured as follows:

• 1. Block A is a signaling device which consists of at least one antenna 1 as well as known down-converters 2 (low-noise amplifier LNA). The received signals may come from different broadcast and / or telecommunications satellites and / or have different polarities (horizontal, vertical). The down converter 2 set the received signals in a conventional manner from the receiving 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 eg 950 - 1760 MHz or preferably 950 MHz and 2050 MHz in order;
• 2. Block B is a head device with a signal processing device 400, are arranged in the channel-specific converter 4. The channel-specific converter 4 will be described in more detail in particular with reference to FIG. Various embodiments of the signal processing device 400 are shown in Figures 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 discharge devices 14 to user sockets 15.

Block A of the system according to the invention, that is, the signaling device as shown, for example, in Fig. 3, consists of antennas 1 which receive the signals from television channels transmitted via satellites. If the antennas are parabolic antennas, a down converter 2 is arranged in each case at the focal point of an antenna 1, which measures the received signals in a manner known per se from the satellite television reception frequency range of e.g. 10.7 - 12.5 GHz in the intermediate frequency range between 950 MHz and 2050 MHz (commonly referred to as "first intermediate frequency") implement. Such down-converters 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 down-converters 2 (or a down-converter with two outputs) depending on whether signals of one or two polarities (horizontal, vertical) per antenna are to be received. If the antenna 1 receives signals of one polarity, a down converter 2 is provided; receives the antenna 1 signals of two polarities, two down converter 2 are provided.

The down converter 2 are each connected to a cable 3 on the output side. In various 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 converter 4 of the head device B are preferably integrated in at least one converter module 40, wherein the converter module 40 is connectable at its input via a cable 3 with a down converter (LNA / LNB) 2 and at its output to the distribution cable 13 (coaxial cable). Preferably, the distribution cable 13 is connected to the output of an amplifier 6, which may be the ("second") mixer 5 downstream.

Each channel-specific converter 4, the circuit design is still explained in detail with reference to Figure 7, has two inputs and two outputs.

As shown in Figures 3, 4, 5, 6 and 9, the channel-individual converter 4 a converter module 40 are connected together in such a way that an input (eg EC1 in Figure 7) of a first converter module with the input (eg EC2) of a second (not shown in Figure 7) converter module, which is adjacent to the first converter module is connected. Similarly, an output (e.g., SC1) of the first converter module is connected to the output (e.g., SC2) of the second converter module (ladder circuit).

This chain circuit structure is characterized by the practically important advantage that not every channel-specific converter 4 is to be connected via a separate cable 3 with a down converter 2 and that moreover not every channel-specific converter 4 via a separate cable with a ("second") Mixer (5) to connect upstream of the distribution cable 13.

It can be provided that each of the two inputs each, e.g. via a respective known connection bridge 7 is connected to an input of an upstream channel-specific converter 4 and to the input of a downstream channel-specific converter 4. Likewise, with regard to the outputs, it can be provided that each of the two outputs is in each case connected, for example. via a respective known connection bridge 7 with an output of an upstream channel-specific converter 4 and with the output of a downstream channel-specific converter 4 is. Preferably, an identical housing is provided for each individual channel converter 4, that is to say a housing of the same spatial dimensions, at which the input and output connections are arranged at the same locations. This allows the use of identical connection bridges 7, with each of 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 drawn in each case on the right in FIGS. 4 and 5 in a converter module) with a cable 3 which generates the signals generated by the down converters 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 supply source 11 which supplies the converters 4 and an amplifier 12 provided for each signal processing unit 400.

These channel-specific converter 4 take on the input from the down converters 2 and transmitted via the cable 3 signals or channels in the intermediate frequency range and put 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 converter 4, which is 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 (see Figure 3, block B, reference number 8 above the converter 4, right converter module 40 in Figure 5, Figure 9, reference numeral 8 above the converter 4).

Likewise, outputs of the channel-specific converter 4 can be terminated with an ohmic resistor 8 of 75 ohms (see Figure 3, block B, reference numeral 8 below the converters 4; right and left converter modules 40 in Figure 5. Figures 6 and 9, reference numeral 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 a 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 by means of a connecting cable 10 in the arrangement of supply source 11 and amplifier 12. The amplified signal is supplied to the second mixer 5.

The channel-specific converter 4 is preferably configured as follows: On the 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 Through input loss <1.2 dB On the output side frequency range 950 ... 1950 (or 2050) MHz Max. Output level - 25 ± 5 dBm Output level control range 15 dB bandwidth 27 MHz 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 loss <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 that form a converter module 40 (input E1) as well as second signals that are formed by the downconverters 2 (input E2) as well as third signals that are output from antennas can transmit the signals receive terrestrial transmitter, the second mixer 5 are fed. At this mixer 5, the distribution cable 13 is connected on the output side. Alternatively, it is provided that the mixer 5, an amplifier 6 is connected downstream, to the output side, the distribution cable 13 is connected.

As shown in Fig. 3, the distribution network C consists of a single distribution cable 13 on which all channels which are FM-modulated are transmitted. The distribution cable 13 is formed by a coaxial cable and leads to discharge devices 14 , which decouple the signal to various 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 converter 4 is equal to the number of channels which are coupled into the distribution cable 13 and transmitted via the discharge devices 14 to the user sockets 15. 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.

FIG. 7 shows an embodiment of a channel-specific converter 4. Two inputs EC1 and EC2 are electrically connected to each other and to a repeater 42 via a directional coupler 41. The inputs EC1 and EC2 are mechanically designed in such a way that known connection bridges (7 in Figure 4) can be used to connect each with an input of an adjacent channel-specific converter. In this way, several channel-specific converters can be integrated into a converter module. This form of connection thus consists in that each of the two inputs EC1, EC2 is connected to an input of an upstream channel-specific converter 4 or to the input of a downstream channel-specific converter 4, in each case via a known connection bridge. Likewise, each of the two outputs SC1, SC2 of the converter 4 is in each case connected, for example via a respective known connection bridge, to an output of an upstream channel-specific converter 4 or to the output of a downstream, individual converter 4. This connection form has the advantage that distribution devices that would otherwise be downstream of the down converters 2 and connection cables between these distribution devices and channel-specific converters are not needed.

The amplifier 42 amplifies the supplied signals e.g. in the frequency band from 950 to 2050 MHz. The signals are fed to an input-side tracking filter 43. This filter is a bandpass filter which is tuned to the selected input channel frequency by means of 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 driven by a local oscillator (OL) 45, which in turn is driven 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 whose cut-off frequency is, for example, 600 MHz. Thus, the signal of the local oscillator 45 and formed during the mixing process, unwanted signals are eliminated.

Subsequently, the signal is filtered by means of a SAW 50 surface acoustic wave filter, e.g. has a bandwidth of 27 MHz at a center frequency of 479.5 MHz. The surface wave filter SAW before or. Downstream amplifiers 48 and 51 increase the signal level so that the losses caused by the SAW filter 50 are compensated.

The mixer 52 connected downstream of the amplifier 51 mixes the signal of the 479.5 MHz frequency signal selected at the input with a signal formed by a local oscillator (OL) 53. The local 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 band-pass filter. The filter 55 eliminates the unwanted signals formed in the mixture made by the mixer 52. At the output of the filter 55 is then the signal of the frequency converted channel, which is supplied to an amplifier 56.

The gain of the amplifier 56 is controllable, so that the levels of the frequency converted channel signal can be set to predetermined values (see, for example, in Fig. 8, the channels 1 and 5).

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 connection bridges (7 in FIG. 4) can be used for connection to one output of an adjacent channel-specific converter.

As shown in FIG. 7, the converters 4 may include 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 may control the amplifier 56. To the microprocessor 49 may e.g. an input unit 16 can be connected via a 4-cable bus, via which data of a predefinable input and output frequency and / or control data for the amplifier 56 (signal amplification parameter) can be input to the microprocessor 49.

The input unit 16 may comprise a controller 162 (in particular a microprocessor MP), a program associated with the controller 162 being e.g. depending on the cut-off frequencies of the respective intermediate frequency range (950 MHz, 2050 MHz), channel bandwidths and channel spacings and signal levels of the channel signals, data corresponding to given technical specifications and input to the microprocessor 49 of the channel-specific converter 4. The input unit 16 includes a keyboard 161, the controller 162, and a display 163. On the display, data inputted to the keyboard 161, prompt information, and information indicating the state of the converter after its setting by the input data are displayed. The input unit 16 can be designed as a remote control transmitter with a transmitting device which transmits the data to be input to a receiving device which 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 it can also be provided a glass fiber.

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

As shown by way of example in FIG. 8, the signals E1, 2, 3, 4, 5 and 6 are input to the input E1 which originate from a satellite, have a bandwidth of 27 MHz, and, as described, have been converted by channel-specific converters in the frequency band between 950 and 2050 MHz. The input E2 is supplied with signals of channels 7, 8, 9, 10, 11, 12, 13 and 14 originating from a satellite, having a bandwidth of 27 MHz and, as described, channel-specific converters in the frequency band between 950 and 2050 MHz have been implemented.

At the entrance E3 are 6 terrestrial TV channels with 8 MHz bandwidth in the frequency band between 47 and 860 MHz.

The signals of the channels which 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 with respect to the coupling of the signals via the mixer output S in the distribution cable 13.

The channels 2, 4 and 6, which are present at the input E1, were so frequency converted in the channel-specific converters 4 that no channels of the same frequencies are present at the input E2. The channels 1 and 3 at the input E1 are arranged in frequencies between the non-desired channels 7 and 8 or 9 and 10, which are present at the 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 the channel 3 is set to a value of at least 15 dB above the corresponding level of the channels 9 and 10.

The channel 5 of the input E1 is arranged in the same frequency as the unwanted channel 12 which is present at the input E2, wherein the signal or power level of the channel 5 is 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 superimposed channel and the frequency of the channel (s) to be superposed: at different frequencies (see channel 1, which superimposes channels 7 and 8) the level difference is at least 15 dB; at the same frequency (compare channel 5, superimposed on channel 12) the level difference is at least 20 dB. The channels configured at this time in terms of frequency and level at the inputs E1, E2 and E3 of the mixer 5 are coupled by the mixer at the output S in the distribution cable 13 in that arrangement, which is shown in Figure 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 1 of input E1 at output S. Since channel 1 is set to a signal level which is at least 15 dB above the levels of channels 7 and 8, only channel 1 is visible to the system user without channels 7 and 8 generating interference.
  Similarly, at the output S, the channels 9 and 10 of the input E2 are superimposed by the channel 3 of the input E1. In addition, in the distribution cable 13 at the output S of the channel 5 of the input E1 is coupled in the frequency position of the channel 12 of the input E2, wherein channel 5 superimposed on the channel 12, since the signal level of channel 5 is at least 20 dB above the channel 12.
  In addition, in the distribution cable 13 of the channel 4 (originally at the input E1) between the channels 3 (originally at the input E1) and 11 (originally at the input E2) coupled and the channel 6 (originally at the entrance E1) is between the channels 13 ( originally at the entrance E2) and 14 (originally at the entrance E2) coupled. The channels 4 and 6 are thus inserted in frequency in frequency positions free at the input E2.

Overall, therefore, the channels in the frequency band from 47 to 860 MHz and the channels 1, 2, 3, 4, 11, 5, 13, 6 and 14 in the frequency band from 950 to 2050 MHz made available to the system user. Also, the channels 7, 8, 9, 10 and 12 are transmitted on the distribution cable 13; However, these are superimposed so that they are not made available to the system user. In the case of the signal level difference of at least 15 dB provided according to the invention, the overlapping channels in the terminals which can be connected to the user sockets can be represented in good reception quality.

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

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

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

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

Each down converter 2 (Figure 9) selects one polarity and converts the 10.9-12.5 GHz frequency band to the 950-2050 MHz frequency band such that in each cable 3 at the nodes g, h, i, j, k are the channels that belong to the same satellites and to the same polarity.

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

From all available channels at the nodes d - k desired channels are selected. Thus, for example, the existing at node k channels 60, 36, 44, 2, 6, 12, 18 and 24 are not further processed, while instead at the circuit points g, h, i, j, pending channels 65, 72, 68th , 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, wherein the channel-specific converters 4 of the modules 40 are 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 overlaid or free frequencies.

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

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

The channels at node n must 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 to be superimposed. This difference in level ensures that the channel that overlays another channel is received without interference from the channel that has been overlaid.

After carrying out the mixing operation in the second mixer 5, one or more channels are obtained, which are shown in FIG. 10, these channels then being distributed via the single distribution cable 13. In this case, as exemplified in Fig. 10, channel 65 is superimposed on channel 60 (compare greater amplitude of 65 versus 60), channel 72 on channel 36, channel 68 on channel 44, channel 82 the channel 2, the channel 77 the channel 6, the channel 17 the channel 12, channel 89 the channel 18 and channel 41 the channel 24th

According to the invention, it is thus provided that signals, in particular television signals transmitted by satellites of different channels, are distributed in a shared antenna system. The signals are received in a signaling device A and the received signals of a certain polarity (H, V) converted from a receiving frequency band into signals in an intermediate frequency band. The converted into the intermediate frequency band signals are processed and the processed signals are transmitted via a single distribution cable 13 in the intermediate frequency band to user sockets 15. In this case, individual predeterminable channels in the intermediate frequency band are converted into other channels in the intermediate frequency band.

In the intermediate frequency band converted first channels 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.

LIST OF REFERENCE NUMBERS

A

Signal generation means

B

head means

C

distribution

EC1, EC2

Inputs from 4

SC1, SC2

Outputs of 4

OIL

local oscillator 45, 53 (in 4)

1

antenna

2

Down converter LNA / LNB

3

electric wire

4

channel individual converter
41, 57 Directional coupler
42 amplifiers
43, 55 lag filter
44, 52 mixers
45, 53 local oscillator OL
46, 54 PLL circuit
47 lowpass
48, 51 amplifiers
49 microprocessor
50 SAW filters

40

converter module

400

Signal processing device

5

second mixer

6

amplifier

7

connecting bridge

8th

load

9

first mixer

10

connection cable

11

supply source

12

amplifier

13

Distribution cable (derivation)

14

dissipation devices

15

users outlets

16

input unit
161 keyboard
162 control unit
163 display

Claims (14)

1. System for distributing signals, particularly a community antenna system for distributing television signals from different channels which, in particular, are transmitted via satellites, the system exhibiting

   - a signal acquisition device (A) having at least one antenna (1) which receives signals, and at least one down converter (LNA/LNB2) which converts received signals of a particular polarity (H, V) from a received frequency band into signals in an intermediate-frequency band,

   - a head device (B) which follows the signal acquisition device (A) and which exhibits at least one signal processing unit (400), the input of which is connected via a cable (3) to the down converter (LNA/LNB 2) and the output of which can be connected to a single distribution cable (13) via which the processed signals in the intermediate-frequency band are transmitted to user sockets (15),

   the signal processing unit (400) of the head device (B) exhibiting channel-associated converters (4), each channel-associated converter (4) converting a presettable channel in the intermediate-frequency band into another channel in the intermediate-frequency band, characterized in that the channel-associated converter (4) exhibits a controllable amplifier (56) by means of which television signals supplied to the channel-associated converter (4) are amplified and in that the system exhibits a device (5) which superimposes the television signals amplified by the controllable amplifier (56) of the channel-associated converter (4) on other television signals which are supplied to the device (5).
2. System according to Claim 1, characterized in that the channel-associated converter (4) exhibits a microprocessor (49) which controls the amplifier (56).
3. System according to Claim 2, characterized in that the microprocessor (49) controls the conversion of a presettable channel in the intermediate-frequency band into another channel in the intermediate-frequency band.
4. System according to Claim 2 or 3, characterized in that the microprocessor (49) of the channel-associated converter can be connected to an input device (16) external to the converter, via which data can be input which designate signal amplification parameters for controlling the amplifier (56).
5. System according to Claim 2, 3 or 4, characterized in that the microprocessor (49) of the channel-associated converter can be connected to an input device (16) external to the converter, via which data can be input which designate a presettable input signal frequency of a channel to be converted and a presettable output signal frequency of a converted channel.
6. System according to Claim 4 or 5, characterized in that the input device (16) external to the converter exhibits a controller (162).
7. System according to one of the preceding claims, characterized in that channel-associated converters (4) of the head device (B) are integrated in at least one converter module (40) and in that the converter module (40) can be connected at its input to the down converters (LNA/LNB2) via the cable (3) and at its output to the distribution cable (13).
8. System according to Claim 7, characterized in that the converter module (40) exhibits at least two channel-associated converters (4) and in that the channel-associated converters (4) in the converter module (40) are connected to one another in such a manner that one input (EC1) of a first channel-associated converter is connected to one input (EC2) of a second channel-associated converter which is located next to the first channel-associated converter and in that one output (SC1) of the first channel-associated converter is connected to one output (SC2) of the second channel-associated converter.
9. System according to Claim 8, characterized in that the connection of the inputs of two adjacent channel-associated converters (4) and/or the connection of the outputs of two adjacent channel-associated converters (4) is implemented by links (7).
10. System according to one of the preceding claims, characterized in that the channel-associated converter (4) exhibits a tracking filter (43, 55) at the input end and/or at the output end.
11. System according to one of Claims 7 - 10, characterized in that a number of 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).
12. System according to one of the preceding claims, characterized in that the system exhibits a second mixer (5) having at least two inputs (E1, E2, E3), in that one of the inputs (E1) can be connected to the output of the converter module (40), in that a second input (E2, E3) can be connected to a down converter (LNA/LNB 2) and in that the second mixer (5) exhibits an output (S) to which the distribution cable (13) can be connected.
13. System according to one of the preceding claims, characterized in that the signal levels of television signals of different channels which are superimposing and subject to superimposition differ by at least 15 dB.
14. Channel-associated converter (4) in a system for distributing signals, particularly a community antenna system for distributing television signals from different channels which, in particular, are transmitted via satellites, the system exhibiting

    - a signal acquisition device (A) having at least one antenna (1) which receives signals, and at least one down converter (LNA/LNB 2) which converts received signals of a particular polarity (H, V) from a received frequency band into signals in an intermediate-frequency band,

    - a head device (B) which follows the signal acquisition device (A) and which exhibits at least one signal processing unit (400), the input of which is connected via a cable (3) to the down converter (LNA/LNB 2) and the output of which can be connected to a single distribution cable (13) via which the processed signals in the intermediate-frequency band are transmitted to user sockets (15),

    the signal processing unit (400) of the head device (B) exhibiting channel-associated converters (4), each channel-associated converter (4) converting a presettable channel in the intermediate-frequency band into another channel in the intermediate-frequency band, characterized in that the channel-associated converter (4) exhibits a controllable amplifier (56) by means of which television signals supplied to the channel-associated converter (4) are amplified and in that the system exhibits a device (5) which superimposes the television signals amplified by the controllable amplifier (56) of the channel-associated converter (4) on other television signals which are supplied to the device (5).

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