EP2608430B1 - Device for processing high frequency signals - Google Patents

Description

The present invention relates to a device for processing high-frequency signals according to the preamble of claim 1.

The SMATV / MATV networks essentially have a signal recording system, as well as a head unit and a distribution network.

The signal recording system consists of various antennas that receive telecommunication signals and which are generally located outside a building in its highest area and are generally difficult to access.

The antennas of the signal recording system usually have devices which are connected to or integrated in the outputs of the antennas and which enable the received signals to be amplified, so that the quality level of these signals is improved. The signals are transferred to the head unit and / or distributed directly, in the case of individual installations, in better conditions.

Various types of devices are also known which are connected directly to the antenna and which serve to amplify the level of the signal received by the antenna and to compensate for losses which have arisen in coaxial cables.

These devices are located outside the building in the immediate vicinity of the antenna so that they are difficult to access when changes are made to the devices or when they are replaced.

These devices have some fixed properties that cannot be modified (gain, bandwidth, output level, etc.), although in many cases the properties of the signals to be received vary, either through the introduction of new services or through a change in Signal parameters, including the appearance of new or new interfering signals.

This is the case, for example, with the signals which correspond to the new services which are referred to as long-term evolution (hereinafter LTE).

Due to the division of the UHF frequency band for television and data of the so-called 4th generation Internet, the signals of the terrestrial digital television of the UHF band take up channels 21 to 60 (470 to 790 MHz) and the LTE signals take up channels 61 to 69 (791 to 862 MHz). Therefore, the television transmission units in the 791 to 862 MHz band, channels 61 to 69 are switched off and this band is used for the LTE signals. This process is known as the digital dividend.

Thus the future use of the 791 to 862 MHz frequency band (channels 61 to 69 of the television band) for mobile internet services and wireless broadband access systems will undoubtedly cause the occurrence of a number of disturbances in the television channels which are adjacent to this frequency band and probably also for other channels that are not adjacent, depending on the level of the desired signal and the interfering signal as well as the amplification systems used. It is therefore not possible to predict in advance at which locations and in which MATV / SMATV installations or in which of their components faults will occur as a result of the introduction of new LTE services.

On the other hand, it should be noted that channels 61 to 69 (791 to 862 MHz) are currently used for television services.

This leads to the problem that it is not possible to install devices in advance in order to eliminate the interfering signals that the new LTE service (band 791-862 MHz, channels 61 to 69) have in the existing installations or in the new ones MATV / SMATV services correspond to those places that are suitable for signals of the LTE service (coverage of the LTE service), since this band (791-862 MHz, channels 61 to 69) is currently still used for television services .

Out EP 2 251 927 A1 a dual-response stopband filter is known which eliminates telecommunications and / or mobile phone signal interference. It is located between an input and an output and has two parallel circuits. A variable capacitance is arranged in a first circuit, while a low-pass filter is arranged in a second circuit. The variable capacitance is assigned a first diode connected in series, while the low-pass filter is assigned a second diode connected in parallel.

Out WO 00/03542 A1 (PINNACLE VENTURES LTD [IE]; ARDEMAGNI FIORENZO [IT]; January 20, 2000 (2000-01-20) an "optimized system for distributing television and telecommunication services from a peripheral node to user terminals" is known. The known system has a switching device (1) which is connected to a MATV device (7) which transmits signals bi-directionally between the switching device (1) and user-specific connection points (8) which are connected to user-specific devices (9) The switching device (1) has a filter function with regard to signals which are present in predefinable bands in order to suppress television signals which have an inadequate signal-to-noise ratio SNR.

Out EP 2 290 745 A1 an antenna system is known which has an electrically small antenna for receiving UHF band-channel signals. The known antenna system has a command block which is connected to a demodulator of a receiver or to a processor of the receiver, the command block generating two control signals. A first control signal controls a variable capacitor of an impedance converter and a second control signal controls variable capacitors of a filter network which is connected upstream of the impedance converter. The known antenna system compensates for impedance changes that arise on the basis of the reception conditions at different locations on the basis of signals that the receiver has received.

The invention has for its object to provide a device of the type mentioned, which automatically eliminates interfering radio frequency signals, including those that are introduced by Long Term Evolution (LTE) services.

The device according to the invention is only activated and the interfering high-frequency signals are eliminated, in particular those which are generated by the LTE services, if the occurrence of these interfering signals is detected, the television services being maintained.

This object is achieved by a device of the type mentioned at the outset, which is defined in the patent claims.

The device according to the invention eliminates the disruptive signals that exist at the time the device is installed, as well as disruptive signals that occur after the installation, without the user and / or the installer having to act.

The device according to the invention is arranged in the actual antenna housing or connected to the antenna via an installation coaxial cable; the device detects or detects the occurrence of interfering signals of the LTE type and the power (level) with which they are received.

As soon as the occurrence and the performance of these interfering signals is determined, the device according to the invention changes the frequency frame of the signals to be received. This frequency frame corresponds to the frequency frame of the telecommunication signals that are to be received as desired. All other signals that are not in this frequency frame are rejected.

To accomplish this, the device according to the invention extracts a pattern of the possible interfering signals at the input of the device and determines the occurrence of these signals and their power.

The inventive solution has a special meaning in situations of transition to transmission devices for LTE signals, since the inventive one Solution avoids a delay in the installation of MATV / SMATV systems by the user or the installer.

In addition, installing this device prior to the introduction of LTE services does not eliminate the terrestrial television service while it occupies the 791 to 862 MHz band, channels 61 to 69.

A multitude of advantages are achieved with the invention.

An advantageous embodiment of the device according to the invention is defined in claim 1.

This has the advantage that the second signal, which is arranged in the second frequency range (791 to 862 MHz, channels 61 to 69) when its level is above a reference level, is eliminated at the output of the device.

This prevents interference between the signals between 791 and 862 MHz (LTE signals) and the signals between 470 and 790 MHz that are intended for television services.

In the event that the level of the second signal, which is in the second frequency range (791 to 862 MHz, channels 61 to 69), is not above the reference level, the comparator / decision maker does not block the switching of the second signal to the output, the second signal is switched through to the output of the circuit. This case takes into account the absence of interfering LTE signals and the possibility that television signals are present in the frequency range from 791 to 862 MHz (channels 61 to 69). In the latter case, the device enables the switching of the complete signal or the signal spectrum from 470 MHz to 862 MHz (channels 21 to 69) compared to the first case, which only enables the switching of the signal between 470 and 790 MHz (channels 21 to 60) .

Another advantageous exemplary embodiment of the device according to the invention is characterized in that it has an amplifier.

This has the advantage that signals are present at the output of the device that can be fed into the distribution network. This amplifier can also be arranged outside the device.

This has the advantage that a standard use of the device is created for different types of amplifiers.

A device according to the invention for processing high-frequency signals, in particular for television radio and / or data antennas in SMATV / MATV networks, is described below by way of example, and not by way of limitation, with reference to the drawing.

Figure 1 shows a block diagram of the device according to the invention;

As in Figure 1 shown, the device according to the invention has an input filter 1 at the UHF input (470-862 MHz, channels 21 to 69), an attenuator / isolator 2, a further filter ("first filter") 3, consisting of a high-pass filter (791-862 MHz, channels 61 to 69), a power measuring device (a detector) 4, a comparison circuit / decision maker 5, a switch 6, which preferably consists of there are two switch components, each with a control input, a low-pass filter 7 (470-790 MHz. channels 21 to 60) arranged between the two switch components and a signal amplifier 8, which can be arranged inside or outside the device.
The control inputs of the two preferably identical switch components of the switch 6 are connected to the output of the comparison circuit 5, so that the two switch components are controlled by the output signal Vc of the comparison circuit 5.
On the one hand, the two circuit components are directly connected to one another (connecting cable at the top in Figure 1 ) and on the other hand, a filter, in particular a low-pass filter 7, is connected between them.

As in Figure 1 shown, the input signal I1, which originates from a signal recording device (telecommunications antenna or the like), is introduced into the device according to the invention via a plug at the input IN. This input signal I1 consists, among other things, of signals from terrestrial digital television and possibly of the LTE type. Due to the division of the UHF frequency band into television signals and data of the so-called fourth generation of the Internet (digital dividend), the signals of terrestrial digital television occupy the channels of the UHF band 21 to 60 (470 to 790 MHz = "first frequency range FR1") and that LTE signals occupy the channels of the UHF band 61 to 69 (791 a 862 MHz = "second frequency range FR2").

The input signal I1 is switched by the UHF input filter 1 (470 a 862 MHz, channels 21 to 69), so that the filtered input signal I2 (television signals and possibly LTE signals) are obtained at its output. Subsequently, a pattern I3 (television signals I31 and possibly LTE signals I32) of the signal I2, which is at the output of the Input filter 1 is present, extracted. The extraction of this pattern I3 of the signal I2 is carried out without introducing any losses in the signal I2, thereby avoiding that the quality of the signal I2 which is introduced into the switches 6 is reduced. Basically, I3 (I31 and I32) is equal to I2 (I21 and I22), but in a damped form, where I31 corresponds to the damped signal I21 and I32 corresponds to the damped signal I22.
For example, if I22 has a level of 60 db, I32 has a level of, for example, 30 or 40 db.

The signal I3 (= I31 and I32) at the output of the attenuator / isolator 2 is passed to a first filter 3, which is formed by a high-pass filter (791 to 862 MHz, channels 61 to 69), which has the task of the signal I32 to be selected, which is arranged in this bandwidth and which includes television signals, before the introduction of the LTE services, or LTE signals after the introduction of these services.

At the output of this filter 3, the signal I32 is measured and / or detected by means of the measuring device (the power detector) 4. The level VDetec measured or detected by the measuring device (the power detector) 4 is compared with a predetermined reference level VRef. The predetermined reference level is the level of the maximum power of the possible LTE interference signals which may be present in the signal I2; this level is the level, an amplifier 8 can assume this level at its input without disturbing the corresponding digital television signals which are present in signal I2.

The comparison is carried out in the comparator / decision maker 5, and the signal switches 6 are activated in accordance with the comparison voltage Vc that arises at the output of the comparator / decision maker 5.

If the reference level VRef is greater than the detected level VDetec, the possible LTE signals of the signal I2 would not interfere with the television signals of this signal I2 and consequently the switches 6 are controlled by the voltage Vc that Connect signal I2 (470 to 862 MHz, channels 21 to 69) directly to signal amplifier 8.

In the event that the reference level VRef is less than the detected level VDetec, the signals LTE of the signal I2 would interfere with the television signals of this signal I2 and consequently the switches 6, controlled by the voltage Vc, this signal I2 become a low-pass filter 7 Redirect (470 to 790 MHz. Channels 21 to 60). This low-pass filter 7 eliminates the signals I22 which are in the frequency band of the UHF channels 61 to 69 (791 to 862 MHz), that is to say the LTE signals which are interfering and only the television signals I21 (470 to 790 MHz, channels 21 to 60) of the signal I2 are introduced into and amplified in the amplifier 8 and later they are fed to the output OUT of the device according to the invention.

In this way, the device according to the invention operates in a situation in which there are no interfering LTE signals (level Vdetec of the interfering signal LTE is below the reference level) in such a way that the signal (470 to 862 MHz, channels 21 to 69) is fed directly to the amplifier 8 in order to amplify it there and later to supply it to the output OUT.

In the opposite case, in which the interfering LTE signal is present at a level which is above a power which is capable of interfering with the television signals (level Vdetec of the interfering LTE signal is above a reference level Vref), the inventive method works Device in such a way that the signal I2 (470 to 862 MHz, channels 21 to 69) is switched through the low-pass filter 7 (470 to 790 MHz, channels 21 to 60). This low-pass filter 7 eliminates the signals in the frequency band of UHF channels 61 to 69 (791 to 862 MHz), that is to say the interfering LTE signals and only the television signals (470 to 790 MHz, channels 21 to 60) of signal I2 are introduced into the amplifier 8 and amplified there and later fed to the output OUT of the device according to the invention.

The device described above is designed in such a way that, depending on the output voltage Vc formed by the comparison circuit 5, either the signal I2 (= I21 and I22) is passed to the output OUT of the device (1st case: VDetec is less than (equal how) VRef) or the signal I21 is sent to the output OUT of the device (2nd case: VDetec is greater than VRef).

In the aforementioned 1st case I2 (= I21 and I22) is fed directly to the amplifier 8 or the output OUT of the device, and in the aforementioned 2nd case I2 (= I21 and I22) is passed through the low-pass filter 7, this filter 7 Signal I22 eliminated so that only signal I21 reaches amplifier 8 or output OUT of the device. In the first case, the path from I22 to amplifier 8 or to the output OUT of the device is enabled, and in the second case, the path from I22 to amplifier 8 or to the output OUT of the device is blocked.

The first case also concerns the status in which LTE signals are not yet used; the second case concerns the status in which I21 consists of TV signals and I22 consists of LTE signals.

Reference symbol list

1

Filters at the UHF input

2nd

Attenuator / isolator

3rd

First filter

4th

Power meter / detector

5

Comparison circuit / decision maker

6

counter

7

Filter; Low pass, high pass or band pass filters

8th

amplifier

IN

Entrance; Input connector / connector

OUT

Exit; Output connector / connector

I1

Radio frequency signal at the input of the device

I2

Filtered input signal: high-frequency signal (470-862 MHz, channels 21 to 69), consisting of I21 and I22

I21

High-frequency signal with a frequency of 470 to 790 MHz (FR1), channels 21 to 60, only television signals

I22

Radio frequency signal with a frequency of 791 to 862 MHz (FR2), channels 61 to 69,

• before the introduction of the digital dividend:
  only signals from terrestrial digital television
• after the introduction of the digital dividend:
  only LTE signals

I3

Pattern of signal I2

I31

I21 in subdued form

I32

I22 in a subdued form

FR1

First frequency range

FR2

Second frequency range

Claims (5)

1. Device for processing high-frequency signals,

   - wherein the device has a UHF input (IN) and an output (OUT) and at least a first filter (3),

   - wherein the device is configured in such a way that an input signal (I1) passes through a UHF filter (1) connected downstream of the UHF input (IN), which filter generates a filtered input signal (I2) and is configured in such a way as to filter signals in a frequency range consisting of a first frequency range and a second frequency range,

   - wherein the device is configured in such a way that the filtered input signal (I2) is conducted to a switch (6),

   - wherein the UHF filter (1) and the switch (6) are connected downstream of the UHF input (IN) and wherein the switch (6) is connected on the input side to a comparator circuit (5) and wherein the first filter (3) is connected downstream of the UHF filter (1) and is configured in such a way as to filter signals in the second frequency range (FR2) in accordance with Long Term Evolution, LTE services, after introduction of the digital dividend and in accordance exclusively with terrestrial television services before introduction of the digital dividend,

   - wherein said filtered input signal (I2) comprises a first signal (I21) arranged in said first frequency range (FR1) corresponding exclusively to terrestrial television services, and a second signal (I22) arranged in said second frequency range (FR2),

   characterised in that

   - said comparator circuit (5) is arranged downstream of said first filter (3),

   - the comparator circuit (5) is configured in such a way that the comparator circuit (5) performs a level comparison between the level of the second signal (I22) contained in the filtered input signal (I2) and a reference level (VRef), which is a predefined level corresponding to a level of maximum power of possible interference signals in the second frequency range (FR2),

   - an amplifier (8) can accept the reference level at its input without disturbing corresponding digital television signals present in the input signal (I2),

   - the comparator circuit (5) is configured in such a way that, depending on the level comparison, it enables or blocks the path of the second signal (I22) to the output (OUT) of the device and forms an output signal (Vc) for controlling the switch (6), which is configured in such a way that

   - in a first alternative, if the reference level (VRef) is greater than the level of the second signal (I22), the output of the UHF filter (1) is connected directly to the output (OUT) of the device and enables the path of the second signal (I22) to the output (OUT) of the device, and

   - in a second alternative, if the reference level (VRef) is lower than the level of the second signal (I22), the output of the UHF filter (1) is connected to a low-pass filter (7), which is arranged between the UHF filter (1) and the output (OUT) of the device and which is configured to filter signals in the first frequency range.
2. Device according to claim 1, characterised in that

   - the switch (6) consists of two switch components each having a control input, which is connected to the output of the comparator circuit (5).
3. Device according to claim 2, characterised in that

   - the switch components are identical.
4. Device according to any of the preceding claims, characterised in that

   - the amplifier (8) is arranged between the switch (6) and the output (OUT) of the device.
5. System comprising a device according to one of claims 1 to 3, characterised in that

   - the system has the amplifier (8) outside the device.

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