DE102006034835B4 - Device and method for processing a signal - Google Patents

Abstract

A method for processing a signal that is present on a first line of a plurality of lines (112a, 112b; 510) of a communication system, comprising: separating a first signal portion transmitted in a first direction of a signal present on the first line; generating a first signal, representing the first signal portion; generating a second signal by delaying the first signal by a first predetermined value; adjustable filtering a third signal based on a signal present on a second line of the plurality of lines to generate a fourth signal; combining the second signal and the fourth signal for generating a conditioned signal; andcontrolling the adjustable filtering based on the conditioned signal.

Description

The present invention relates to the field of signal processing, and in particular to the field of signal processing in communication systems with a plurality of lines.

In the case of communication systems, such as, for example, a telephone communication system, an xDSL communication system or other data communication systems, several lines are often brought together, with the lines mutually influencing one another accordingly. For example, the existing telephone line network is increasingly being used for data transmission in order to provide subscribers with additional services such as fast Internet access ( ADSL ) or digital television ( VDSL ) To be able to offer. As the transmission speed increases, the maximum bridgeable range is severely limited. This is due on the one hand to the line attenuation increasing with the frequency and on the other hand to the crosstalk attenuation decreasing with the frequency.

The cable loss is a physical property of the cables and is determined by the cable length and the cable parameters, which in turn essentially depend on the cable diameter and the insulation material. For a given line, the level of the received signal can therefore only be influenced by the power of the transmitted signal. There are precise regulations for the choice of the transmission signal level depending on the transmission method, so that the reception level only depends on the line parameters and the line length. Since a minimum reception level is required for processing the received signal, the maximum achievable range is reduced as the transmission speed increases and thus the frequency bandwidth increases.

In a cable bundle, the different line pairs influence each other accordingly and interfere with the corresponding useful signals. In addition to the strong capacitive coupling of the line pairs within a cable, the crosstalk interference increases with increasing bandwidth of the signals and thus with increasing transmission speed.

The EP1276249A1 describes a device for improving the transmission properties of a bundle of electrical data lines. An adaptive filter that generates an output signal for correcting a signal transmitted on a first data line is provided in the device. The adaptive filter receives at least one signal tapped from a second data line or an external signal as a reference signal and receives the corrected signal transmitted on the data line as an error signal.

Furthermore, in the publication "IFC-active compensation of the near-end crosstalk for DSL transmission", Busboom et al., ITG conference 2005 described a system in which a mixed analog-digital implementation of a compensation filter is used in order to compensate for an audio signal of xDSL transmission systems without separating the signal in a send and receive direction.

EP 1 109 329 discloses a DSL transmission system with far end crosstalk compensation ( FEXT ). A transceiver of a modem on the line connection side is connected to a modem on the network connection side through a transmission channel. EP 1 109 329 write the FEXT Interference as a sum of complex values. The complex values are subtracted from received frequency components to get a complex value without FEXT to obtain. The processing of the complex values is delayed by one symbol in the receiving modem compared to other modems.

The object of the present invention is to improve interference behavior between at least two lines of a plurality of lines.

This object is achieved by a method according to claim 1 and an apparatus according to claim 12.

According to one aspect of the present invention, in order to generate a processed or interference-suppressed signal, a first signal component of a signal present on the first line is separated depending on a transmission direction on the first line to generate a first signal. The first signal represents a signal component transmitted in the first direction of the signal present on the first line. The first signal is time-delayed by a predetermined value, the time-delayed signal being combined with a signal which can be adjusted by filtering one on one based on a second line of the plurality of lines present signal. The adjustable filtering is controlled based on the processed signal.

In one embodiment, the signal component is separated by means of a hybrid circuit, the configuration of the hybrid circuit comprising both passive and active components.

In a further exemplary embodiment, the communication system is a duplex telecommunication system, in a further embodiment the duplex telecommunication system is a full duplex telecommunication system.

In one embodiment, the plurality of lines include a plurality of two-wire lines of a bundle of cables.

A cable bundle is understood here to mean both a plurality of loosely combined lines and a plurality of lines which are firmly connected to one another.

In one exemplary embodiment, the signal present on the first line is an analog signal, for example an xDSL signal, which is based on a digital signal which is subjected to time frequency conversion after symbol coding. The first signal can be present as a digital signal based on the analog signal by means of an analog-digital converter.

It should be noted here that due to the combination of the signal generated by the adjustable filter with a time-delayed signal, it is readily possible to implement the adjustable filter in a purely digital manner. As a result, in particular the advantages resulting from purely digital filtering of a sensitive setting of the filter coefficients and an associated improved processing of the signal, i.e. improved interference suppression of the lines. It should also be noted here that by using a first signal, which is based on a separated signal component, which is dependent on the direction of transmission, improved filtering is made possible, since only the useful signal component, i.e. the signal component, is used to control the adjustable filtering. H. in one embodiment only the received signal component is used and not the transmitted signal component which is also present on the line.

In a further exemplary embodiment, a frequency-dependent separation of the signal present on the first line into a second and a third signal component takes place before the first signal component is separated. In one embodiment, the signal present on the first line can be separated into a second and third signal component by means of a splitter filter. Here, the first signal is only based on the high-pass filtered signal component output at a high-pass output of the splitter filter, i.e. generated a high-frequency portion. The low-pass filtered low-frequency signal component output at a low-pass connection of the splitter filter is combined with the processed signal to form a combined processed signal in this exemplary embodiment. The combining can include, for example, generating a difference signal between the two signals to be combined or a signal that corresponds to the difference between the two signals. For this purpose, a differential circuit can be provided, which generates the above differential signal, for example, by inverting and then summing the two signals. At this point, however, it should be noted that many possible combinations of the two signals, in particular also non-linear combinations with previous attenuations or amplifications of the signals, can also be used in further exemplary embodiments.

In a further exemplary embodiment, when processing the signal present on a first line, not only the signal present on a second line but also a signal present on a third line are taken into account. Here, a signal based on a signal present on the third line is filtered in an adjustable manner in order to generate an output signal, the output signal being combined with the delayed signal and the further signal generated by filtering in order to generate the processed signal. It should be noted at this point that the method described above for two or three signal lines can easily be extended to any number of lines. In order to compensate for the crosstalk of a specific line, an adjustable filtering of a signal based on a signal present on the respective other line is carried out for each of the other lines, the signals generated by the adjustable filtering being combined with the delayed signal ,

As already described above, the adjustable filtering can also be carried out exclusively digitally in this exemplary embodiment, which results in the advantages already mentioned above.

In one embodiment, an echo cancellation signal is additionally generated, which is combined with the other signals generated by the adjustable filtering in order to generate the processed signal. The echo compensation signal is generated depending on a transmission signal of the line.

In other words, in this embodiment, not only the crosstalk, which is both a far crosstalk ( FEXT ) as well as a near crosstalk ( NEXT ) can be compensated, but the interfering echo signal present on the first line is additionally compensated.

It should be noted here that compensation is both a complete removal of the interference signals as well as a partial removal or reduction of the interference signals. The above-described processing of the signal has the advantage that the adjustable filtering can be carried out selectively by separating the signal components on the respective lines, ie it can either compensate for near crosstalk, compensate for long distance crosstalk or both a combination of the two Close crosstalk as well as long distance crosstalk take place. In other words, a transmit signal is tapped on the respective lines to compensate for the near crosstalk, which is applied as an input signal to the adjustable filter. Correspondingly, in order to compensate for long-distance crosstalk, a receive signal is tapped on the respective lines, which serves as an input signal for the adjustable filtering. The separation of the signals on the respective lines into a transmit and receive signal component enables selective compensation, in which it is possible to control by means of a control device which of the signals, ie a transmit signal of the respective lines, a receive signal of the respective lines or both signals , to compensate for the spurious signals to selectively compensate for near crosstalk, far crosstalk, or both.

According to one exemplary embodiment of the present invention, a signal that is present on a first line of the plurality of lines is processed, or the first line is suppressed by frequency-dependent separation of the signal present on the first line into a first and a second signal component. The first signal component is processed, wherein the processed first signal component and the second signal component are combined in order to generate a processed third signal. Combining can include simple summing, linear or non-linear addition, or other types of combinations or combinations.

In one embodiment, it is provided that a first splitter filter is used for frequency-dependent separation. A combination circuit can be used to combine the processed first signal component with the second signal component, which in one exemplary embodiment comprises a splitter filter. The low-pass connections of the two splitter filters can be galvanically, ie. H. be connected to each other in direct current. This has the advantage that bidirectional transmission is ensured, a direct current connection being established via the first line, which enables remote feeding into the communication system.

In a further exemplary embodiment, a telecommunication system has a plurality of lines which are each coupled at a first end to a transmitting / receiving device of a first plurality of transmitting / receiving devices. Furthermore, the telecommunication system has a second plurality of transceivers which are coupled at a second end of the plurality of lines to a device for spreading a signal, as described above.

• 1: ein Blockdiagramm eines Ausführungsbeispiels der vorliegenden Erfindung;
• 2: ein Ablaufdiagramm zum Darstellen eines Verfahrens gemäß einem Ausführungsbeispiel der vorliegenden Erfindung;
• 3: ein Blockdiagramm eines Ausführungsbeispiels der vorliegenden Erfindung;
• 4: ein Ablaufdiagramm eines Verfahrens gemäß einem Ausführungsbeispiel der vorliegenden Erfindung;
• 5: ein Blockschaltbild eines Kommunikationssystems gemäß einem Ausführungsbeispiel der vorliegenden Erfindung;
• 6: ein Blockschaltbild eines Ausführungsbeispiels der vorliegenden Erfindung;
• 7: ein Blockschaltbild eines Ausführungsbeispiels der vorliegenden Erfindung;
• 8: ein Blockschaltbild eines Ausführungsbeispiels einer Gabelschaltung; und
• 9: ein Blockschaltbild eines Ausführungsbeispiels eines Splitterfilters.

Further exemplary embodiments of the present invention can be found in the detailed description with reference to the accompanying figures and the claims. Show it:

• 1 : a block diagram of an embodiment of the present invention;
• 2 FIG. 1 shows a flowchart for illustrating a method according to an exemplary embodiment of the present invention;
• 3 : a block diagram of an embodiment of the present invention;
• 4 : a flowchart of a method according to an embodiment of the present invention;
• 5 : a block diagram of a communication system according to an embodiment of the present invention;
• 6 : a block diagram of an embodiment of the present invention;
• 7 : a block diagram of an embodiment of the present invention;
• 8th : a block diagram of an embodiment of a hybrid circuit; and
• 9 : a block diagram of an embodiment of a splitter filter.

In the following, with reference to the 1 - 9 preferred embodiments of the present invention explained. Identical and / or functionally equivalent components or functional blocks are identified by the same reference symbols in the various figures.

1 shows an embodiment of the present invention, in which a device 100 a first input for processing a signal 110a and a second entrance 110b has, each with lines 112a respectively. 112b are coupled. It should be noted at this point that the lines 112a respectively. 112b In one exemplary embodiment, two-wire lines of a telephone transmission system are such that they can be used for further data transmissions by xDSL transmission services. In the above exemplary embodiments, the transmitted signal is an analog signal, which can contain signal components which are transmitted through appropriate coding of digital data and subsequent time-frequency conversion were converted into an analog signal component. However, the present application is not only limited to systems that transmit analog signals, but can also be applied to systems that transmit digital data.

I The entrance 110a is with an entrance 114a a separator 114 connected to separate a first signal component SigA of a signal present on the first line depending on a carry direction on the first line. In one embodiment, the separator is 114 a hybrid circuit, which is set up to transmit and receive portions of one on the line 112a to distribute the applied signal. The signal SigA is at an output 114b the separating device 114 output. The exit 114b is with an entrance 116a an offset device 116 interconnected to delay the signal SigA. The device for delaying in time can be a delay element, for example, which can be constructed digitally or analogously depending on the signals SigA. In one embodiment, the delay element can comprise one or more latches. An exit 116b the offset device 116 is with a first entrance 118a a combination circuit 118 coupled. The combination circuit 118 has a second entrance 118b on and is trained to the at the entrances 118a and 118b to combine applied signals in a predetermined manner. In one embodiment, the combination includes subtracting the two at the inputs 118a and 118b applied signals. However, other possible combinations of the two signals can also be used, for example non-linear combinations in the combination circuit 118 be performed. An exit 118c the combination circuit 118 is with a knot 120 connected. The knot 120 is with an exit 122 the device 100 connected. Furthermore, the knot 120 with a control input 124a an adjustable filter 124 coupled. The adjustable filter 124 is an adaptive filter in one embodiment. The adjustable filter 124 has a first entrance 124b that with the entrance 110b is coupled to receive a signal on one on the second line 112b applied signal based. The filter 124 has an exit 124c on the one with the entrance 118b the combination circuit 118 is coupled. The filter 124 can be a purely digital filter that is set up to be dependent on that at the control input 124a applied signal an error of at the output 118c the combination circuit 118 to minimize the output of the processed signal. Known algorithms such as an LMS algorithm (least mean square algorithm), an RLS algorithm (recursive least square algorithm), an ELS algorithm (extended least square algorithm) can be used to set the filter. or other known algorithms can be used to minimize errors.

With reference to 2 The mode of operation of the exemplary embodiment described above is explained below.

In one step 200 becomes a first signal portion of one on the line 112a applied signal depending on a transmission direction on the first line by means of the separating device 114 separated. A signal SigA, which represents a signal component transmitted in a first direction, ie for example a received signal component, is in one step 210 by means of the offset device 116 delayed. It should be mentioned at this point that in one embodiment between the separation of the signal component and the time delay 210 an analog-digital conversion of the signal SigA can take place by means of an analog-digital converter. The time delay is carried out with a predetermined value, which can be adjustable and can be adapted, for example, to correspondingly favorable values before or during operation. In one step 212 is by means of the adjustable filter 124 filtering a signal based on a signal present on a second line. That through the filter 124 processed input signal can be directly from the second line 112b tapped signal, but in other embodiments, other signals can be used that are on the on the second line 112b based signal or are correlated with this. Furthermore, only portions of the signal present on the second line can be input to the filter as an input signal 124 be created.

The adjustable filtering generates a signal, which is combined with the time-delayed signal SigA in one step 214 generate a processed or suppressed signal.

Controlling the adjustable filter is done in one step 216 performed based on the conditioned signal, for example by that at the output 118c output processed signal to the input 124a of the filter 124 is returned. In one embodiment, the feedback enables adaptive filtering such that a by crosstalk of the signals from the line 112b on the line 112a Interference signal generated in the processed signal that at the output 118c is spent, minimized or eliminated. The interference signal can be, for example, a near crosstalk, a far crosstalk or a combination of the two interference signals.

Although in the embodiment according to 1 the second line 112b directly with the entrance 124b of the filter 124 at this point, it should be mentioned that in other exemplary embodiments the input 124b of the filter 124 not directly with the line 112b is coupled. For example, a hybrid circuit with the line 112b be coupled to that on the line 112b separate the applied signal into a transmit and receive signal. The transmit and / or receive signal can be selectively sent to the input 124b of the filter, making it possible to have the near-end crosstalk and the far-end crosstalk of the line 112b on the line 112a to compensate selectively.

In one embodiment, the separation device 114 be a hybrid circuit that is implemented in different ways. An embodiment of a hybrid circuit, as can be used in the embodiment described above and the further embodiments, is described below with reference to FIG 8th described.

3 shows an embodiment of the present invention, in which in a signal conditioning device before conditioning the on the first line 112a applied signal a frequency-dependent separation of the on the first line 112a applied signal is performed. This is a first connection 310a , ie a send / receive connection, of a splitter filter 310 with the first line 112a coupled. A second connection 310b of the splinter filter 310 , for example with a low-pass filter of the splitter filter 310 is coupled with an input 312a coupled to a combination circuit. A third connection 310c of the splinter filter 310 , for example with a high pass of the splinter filter 310 is coupled with an input 314a a compensation circuit or signal conditioning circuit 314 coupled. The compensation circuit 314 is in one embodiment corresponding to the device 100 built up. In other exemplary embodiments, however, the compensation circuit can comprise other known compensation circuits for compensating for interference signals. The compensation circuit 314 has another entrance 314b on the one with the second line 112b is coupled to obtain a signal that is connected to one on the second line 112b applied signal is correlated. The compensation circuit 314 generated at an output 314c a corrected signal in which the interference influences the line 112b on the line 112a are adjusted or reduced. The exit 314c is with another entrance 312b the combination circuit 312 coupled. The combination circuit 312 couples the at the inputs 312a and 312b applied signals to a combined processed signal which is sent to an output 316 of the signal processing device is output. In one embodiment, the combination circuit 312 include a splinter filter. In one embodiment, the second port is 310b and the entrance 312a galvanically, ie connected by direct current. This has the advantage that the line 112a a remote feed, for example in a telephone system, enables, however, via the in 3 shown lower branch 318 compensation of high-frequency signals, such as DSL signals, is possible because of the splitter filter 310 frequency-dependent separation of the signals takes place. In addition, even if the compensation circuit fails 314 a connection over the line 112a can be retained as signals above the in 3 shown upper branch between the entrance 312a and the connection 310b is possible.

With reference to 4 the functionality of the in 3 illustrated embodiment explained in more detail. In one step 400 is a frequency-dependent separation of the on the first line 112a applied signal, for example in a high-pass filtered signal and a low-pass filtered signal. A first signal component of the signal components generated by the frequency-dependent separation, for example the high-pass filtered signal component, is in one step 410 through the compensation circuit 314 processed to a regarding line interference 112a generate cleaned or reduced signal. The processed signal component is in one step 420 combined with a second signal component, which is due to the frequency-dependent separation in the step 400 was generated.

5 shows as a further embodiment a telecommunications system 500 , where a plurality of lines 510 in a bundle of cables 512 is summarized. The lines 510 are at a first end 510a with respective inputs of a first signal processing device or interference suppression device 514a coupled. The signal processing device 514a has a plurality of outputs, each one of the lines 510 assigned. The majority of the outputs are each with a transceiver S1 ' . S2 ' ... Sn ' a plurality of transmitting / receiving devices coupled. At a second end 510b of the lines 510 are the lines 510 with respective inputs of a second signal processing device 514b coupled. The second signal processing device 514b has a plurality of outputs, each with a transceiver of a second plurality of transceivers S1 . S2 , ... sn are coupled. In other words, the send / receiving devices S1 . S2 , Sn with the corresponding transmitting / receiving devices S1 ' . S2 ' 'Sn' over the lines 510 which can be, for example, electrical lines for the transmission of telephone communication signals. By merging the lines 510 in the cable 512 occur the electrical couplings known as crosstalk between the respective line pairs, which leads to a fault in the individual connections and a reduction in the maximum transmission rate and / or a maximum bridgeable range.

Like it in 5 is shown are the signal conditioning devices 514a and 514b in each case interposed between the cable ends and the first plurality of transmitting / receiving devices or the second plurality of transmitting / receiving devices.

With reference to 6 will be the example at the end 510b the majority of lines 510 arranged signal processing device 514b explained. In one embodiment, the signal conditioning devices are 514a and 514b constructed in the same way, ie they have the same functional elements.

The signal processing device 514b has a plurality of first connections 600a on, each with one of the plurality of lines 510 are coupled. The signal processing device 514b also has a plurality of second terminals 600b on, each with one of the transmitting / receiving devices S1 . S2 , Sn are coupled. Each of the first ports 600a is with one of a plurality of splinter filters 610 coupled. According to the present application, each device that splits or splits a signal into two or more signal components depending on the frequency should be included under the splitter filter or splitter. The term splitter filter or splitter should therefore be interpreted broadly.

Each of the splitter filters has a first connection 610a on to the signal through the splitter filter 610 to be divided by the respective assigned line 510 to recieve. The splinter filter 610 divides the received signal into a first signal component, which is assigned to a first frequency range, and a second signal component, which is assigned to a second frequency range. In the described embodiment according to 6 is that from the management 510 received signal divided into a low-frequency component and a high-frequency component. The low-frequency component is on a second connection 610b issued during the high frequency portion of a third connection 610c is issued. The third connection 610c is with a first connection 612a a compensation circuit 612 coupled below with reference to 7 is explained in more detail. A second connection 612b the compensation circuit 612 is with a third connector 614c another splinter filter 614 coupled.

The second connection 614b of the splinter filter 614 is with the second connector 610b of the first splinter filter 610 coupled. There is also a first connection 614a of the splinter filter 614 with one of the transmitting / receiving devices S1 - Sn coupled. Each of the plurality of compensation circuits 612 has a plurality of inputs 616 to receive a signal based on a signal or correlated with a signal on one of the other lines of the plurality of lines 510 is transmitted. More specifically, the compensation circuit 612 a first entrance 616a that receives a signal that is correlated with the signal present on the second line or based on the signal present on the second line. In a corresponding manner, the first of the plurality of compensation circuits 612 a second or nth input 616b respectively. 616n in order to receive a signal which is based on or is correlated with a signal present on the third line or nth line. An input is thus provided for each further one of the plurality of lines in order to receive a signal which makes it possible to compensate for the disturbance caused by the respective line on the first line. This means that for each of the lines, the interference caused by the respective other lines is compensated.

With reference to 7 is now the structure of the compensation circuit 612 are explained in more detail. The compensation circuit 612 has a first hybrid or hybrid circuit 710 with a first connection or send / receive connection 710a on the one with the connector 612a is coupled. The hybrid 710 allows one on the first connector 710a received reception signal to a second connection or reception connection 710b create or output. Furthermore, the hybrid circuit enables 710 , one on a third connection or transmission connection 710c received transmission signal at the first connection 710a to output this via the one with the first connection 710a to transmit coupled line. The second connection 710b is with an entrance 712a of an analog-digital converter 712 coupled. An exit 712b of the analog-digital converter 712 is with an entrance 714a a delay element 714 coupled. An exit 714b of the delay element 714 is with a combination circuit 716 which couples a plurality of summation nodes 718 includes.

The combination circuit has an output 716a on that with a digital-to-analog converter 620 and with control inputs 622a a plurality of adaptive filters 622 is coupled. Between the exit 716a and the digital-to-analog converter 620 is a scaling element 624 arranged, which performs a weakening or reinforcement to adapt to the line conditions. The digital-to-analog converter 620 is with a third connection or receive connection 726c a second hybrid 726 coupled. A first connection 726a or send / receive connection of the hybrid circuit 726 is with the connection 612b coupled. A second connection 726b the fork system 726 is with a second scaling element 728 coupled, which in turn with an echo cancellation circuit 730 and the third port 710c the first hybrid 710 is coupled. More specifically, the scaling element is 728 with an entrance 730a the echo cancellation circuit 730 interconnected, the echo cancellation circuit 730 an exit 730b having a first summation node of the plurality of summation nodes 718 is coupled. The exit 716a the combination circuit 716 is also with a control input of the echo cancellation circuit 730 coupled.

The majority of adaptive filters 622 has a plurality of inputs 622b on, each with one of the plurality of inputs 616a . 616b . 616c the compensation circuit 612 is coupled. Any of the adaptive filters 622 also has an output 622c on, each with one of the summation nodes 718 is coupled.

The compensation circuit 612 also has a plurality of first taps 732 between the scaling element 728 and the echo cancellation circuit 730 or between the scaling element 728 and the hybrid 710 on. Furthermore, is between the analog-to-digital converter 712 and the delay element 714 a plurality of second taps 734 intended. The taps 732 serve to tap a transmission signal transmitted via the compensation circuit in order to transmit this transmission signal to a further compensation circuit, that of another of the plurality of lines 510 is assigned to the respective assigned inputs 616a . 616b . 616c feed in order to enable compensation of the near crosstalk for the further compensation circuit. The connections serve in a corresponding manner 734 addition, one via the compensation circuit 612 tapped received signal, and this to one or more further compensation circuits 612 , the other lines 510 are assigned to the assigned inputs 616a . 616b . 616c to compensate for the long distance crosstalk of the other lines.

The mode of operation of the signal processing device will now be described in more detail below 514b and the compensation circuit 612 described.

This in 5 shown telecommunication system 500 is a bidirectional communication system in which both the first plurality of transceivers and the second plurality of transceivers both send and receive signals. A signal sent by a transceiver of the second plurality is from the splitter filter 614 divided or separated into a low-frequency and high-frequency signal component. In one exemplary embodiment, the division has the effect that data signals which are assigned to higher-frequency signal components are separated from low-frequency signal components, for example voice channels. The higher frequency signal components are via the third connection 614c applied to the compensation circuit in order to process or suppress the signals. The low-frequency signal components are via the connections 614b and 610b of the two splinter filters 614 and 610 bridged. This enables interference suppression to be carried out even on lines with remote supply, since the remote supply current is bridged like the low-frequency signal component. Likewise, in the event of a malfunction-related failure of the compensation circuits 612 the low-frequency connection, for example a telephone connection, is retained. Conversely, one is on the lines 510 transmitted signal to the splitter filter 610 divided into a low-frequency and a higher-frequency signal component, the low-frequency signal component via the connection between the connections 610b and 614b the one with the splinter filter 610 and 614 is bridged while the higher-frequency signal component of the compensation circuit 612 is fed.

It should be noted at this point that in one embodiment the devices 514a and or 514b only through the compensation circuit 612 can be formed, ie there are no splitter filters in this embodiment 610 and 614 used to perform a frequency-dependent division of the received or transmitted signal.

It is understood that at the opposite end 510a the majority of lines 510 arranged device 514a corresponding to the signal processing device 514b can be trained. In other words, in the embodiment shown, the telecommunications system 500 a symmetrical Communication system in which through the device 514a that of the first plurality of transceiver S1 ' . S2 ' 'Sn' received transmission signals are bridged while those from the lines 510 received signals are compensated, and accordingly that of the second plurality of transceivers S1 . S2 , SN transmitted transmission signals in the signal processing device 514b be bridged while by the majority of line 510 received signals are compensated for or corrected for the mutual interference by the lines.

To make this possible, separate them in the compensation circuit 612 provided hybrid circuits 710 and 726 a signal in a transmitting part and a receiving part. The broadcast share is over the in the 7 shown upper branch from the hybrid 726 to the hybrid 710 transfer. Accordingly, the proportion of reception is higher than that in the 7 shown lower branch of the hybrid 710 to the hybrid 726 transfer. Compensation is carried out for the received signal, initially by means of the analog-digital converter 712 the analog received signal component is converted into a digital signal. The digital received signal component is by means of the delay element 714 delayed by a predetermined value, which is adjustable and can be set adaptively during operation in one embodiment. The delayed signal is by means of the combination circuit 716 combined or linked with respective compensation signals by the adaptive filters 622 be generated. The combined signal, which represents a cleaned signal in such a way that interference on the line is cleaned or reduced, is converted into an analog signal by means of the digital-to-analog converter 620 converted, with a scaling by means of the scaling element to adapt to the line conditions 624 can be carried out. The adjusted analog signal is then via the hybrid circuit 726 output to the respectively assigned transmitting / receiving device.

To generate the compensation signals, the adaptive filters each receive signals that are correlated with signals or based on signals that are on the other lines of the plurality of lines 510 issue. More specifically, the taps 732 and 734 in each case a send or receive signal is tapped, which is assigned to this line and at the inputs 616a . 616b . 616n created by other compensation circuits. Thus, each of the compensation circuits 612 about the taps 732 respectively. 734 a transmit or receive signal is provided which is based on the signal or correlated with the signal which is present on the respectively assigned line. The on the taps 732 respectively. 734 Tapped signals are sent to the other compensation circuits 612 transmitted to the inputs of the adaptive filter 622 to provide the corresponding signal in each case in order to compensate or reduce a compensation of the interference influences which are assigned to the respective line. The adaptive filters can be set before or during operation to minimize errors. The setting is made via feedback of the output signal of the combination circuit 716 to the control inputs of the adaptive filters 622 ,

In one embodiment, a signal can also be tapped directly after the respective summation node that is assigned to a respective adaptive filter and can be applied as a reference signal or error signal to the control input of the adaptive filter.

Various algorithms, for example an LMS algorithm, an RLS algorithm or other known algorithms, can be used to adapt the filter coefficients. It should be noted at this point that between the analog-to-digital converter 712 and the digital-to-analog converter 620 there is a fully digital signal path so that both the adaptive filter 622 as well as the delay element 714 are purely digital. In particular, this will also be the case with the taps 734 tapped signal as a digital signal and tapped to the inputs of the digital adaptive filter 622 created, whereby an additional analog-digital conversion of these signals is not required. In addition to the crosstalk compensation described above, using the echo cancellation circuit 730 echo cancellation performed. The echo cancellation circuit 730 receives as the input signal the transmission signal sent by the nearby transmitting / receiving device via the hybrid circuit 726 and performs echo cancellation based on the transmit signal of the near-end transceiver by sending an echo cancellation signal to one of the summing nodes of the combination circuit 716 is created.

For adaptive adjustment of the echo compensation, this is done at the output of the combination circuit 716 Output compensated signal to a control input of the echo cancellation circuit 730 created. The echo cancellation circuit 730 can be formed as an adaptive filter corresponding to the adaptive filters 622 minimizes error performance using the known algorithms.

The following will refer to 8th an embodiment of one used in the previous embodiments Hybrid circuit can be described. At this point it should be noted that the in 8th The hybrid circuit described is only one exemplary embodiment of a hybrid circuit, and a large number of further hybrid circuits are known to the person skilled in the art which can be used in the exemplary embodiments of the present invention. The hybrid 800 has a first connection 800a on that of a two-wire connection of the hybrid circuit 800 represents. The hybrid 800 also has a second connection 800b and a third port 800c which together form the four-wire connection of the hybrid circuit. More specifically, the connection provides 800a a send / receive connection, the connection 800b a send port and the port 800c a receive connection of the hybrid circuit 800 represents.

The connection 800c is with a differential input of a differential amplifier 810 coupled. The differential amplifier 810 has a first and a second output, a first output having a first resistor 812a and a first branch 814a a cross-arranged resistor network with the resistors R1 and R2 is coupled. The second output of the differential amplifier 810 is with a second resistor 812b and a second branch 814b of the cross-linked resistor network.

One of the connection 800c received signal is first by means of the differential amplifier 810 amplified and over the two resistors 812a and 812b to the connector 800a and thus to the one with the connection 800a coupled line output. The resistance values of the resistors 812a and 812b have a value of about 50 ohms depending on the characteristic impedance of the line. In one embodiment, a transformer can be interposed to adapt the voltage and current conditions to the amplifier. One on the connector 800a received signal is tapped via the cross-arranged resistor network and at the connection 800b output. At the same time, the existing echo signal, which is caused by the transmit signal of the amplifier, is greatly attenuated or suppressed. For the resistors R1 and R2 the resistor network is provided in one embodiment, much larger values than for the resistors 812a and 812b to be used in order not to unnecessarily increase the power requirement. The resistance values of the resistors used in the resistor network R1 and R2 are in this embodiment in a range of 10 kOhm or more 10 kOhm.

The following will refer to 9 an embodiment of a splitter filter or splitter, which is used in embodiments of the present invention, will be explained in more detail. At this point it should be noted that in 9 The exemplary embodiment described is merely an example of an implementation of a splitter filter, as is used in exemplary embodiments of the present invention. The term splitter filter or splitter should be interpreted broadly and include any device or device that divides or splits a signal into two or more signal components depending on the frequency of the signal components. 9 shows on the left side the block circuit symbol used in the described exemplary embodiments and on the right side an exemplary embodiment for the implementation of this block circuit symbol. As in 9 can be seen, shows the splitter filter 900 a first connection 900a on that with a low pass filter 910 and a high pass filter 912 is coupled. The high pass filter 912 has a capacitor for each of the sub-lines of the two-wire line, which acts as a high-pass filter. Furthermore, the low-pass filter has an inductance for each of the sub-lines of the two-wire line. A second connection 900b is with the high pass filter 912 connected while a third port 900c with the low pass filter 910 connected is.

Although in 9 If the splitter filter shown divides into a higher-frequency signal component and a low-frequency signal component by means of a passive high-pass filter or passive low-pass filter, other components, for example active components, can also be used to implement a high-pass or low-pass filter in other exemplary embodiments. It should also be noted at this point that in one embodiment, the inductances of the low-pass filter of the two splitter filters 610 and 640 can be summarized because the two low-pass connections of the splitter filter 610 and 640 according to 6 are coupled together.

Although 2-wire lines have been shown in the exemplary embodiments described, it should be understood that other lines, for example 1-wire lines, which transmit signals to ground, can also be used in other exemplary embodiments.

LIST OF REFERENCE NUMBERS

100

contraption

110a

entrance

110b

entrance

112a

management

112b

management

114a

entrance

114b

output

114

separator

116

offset means

116a

entrance

116b

output

118a

entrance

118b

entrance

118c

output

118

combining circuit

120

node

122

output

124a

control input

124b

entrance

124c

output

124

filter

200

step

210

step

212

step

214

step

216

step

300

Signal conditioning device

310a

first connection

310b

second connection

310c

third connection

310

splitter filter

312a

entrance

312b

entrance

312

combining circuit

314a

entrance

314b

entrance

314c

output

316

output

318

lower branch

314

compensation circuit

400

step

410

step

420

step

500

telecommunications system

510a

first end

510b

second end

510

cables

512

cable bundle

514a

Signal conditioning device

514b

Signal conditioning device

600a

first connections

600b

second connections

610a

first connection

610b

second connection

610c

third connection

610

splitter filter

612a

first connection

612b

second connection

612

compensation circuit

614a

first connection

614b

second connection

614c

third connection

614

splitter filter

616

inputs

616a-n

entrance

620

Digital to analog converter

622a

control inputs

622b

inputs

622c

output

622

adaptive filter

624

scaling link

710a

first connection

710b

first connection

710c

first connection

710

hybrid

712a

entrance

712b

output

712

Analog to digital converter

714a

entrance

714b

output

714

delay

716a

output

716

combining circuit

718

Summing node

726a

first connection

726b

second connection

726c

third connection

726

hybrid

728

scaling link

730a

entrance

730b

output

730

Echo cancellation circuit

732

first taps

734

second taps

800a

first connection

800b

second connection

800c

third connection

800

hybrid

810

differential amplifier

812a

first resistance

812b

second resistance

814a

first branch

814b

second branch

900a

first connection

900b

second connection

900c

third connection

900

splitter filter

910

Low Pass Filter

912

High Pass Filter

Claims (22)

A method of conditioning a signal applied to a first line of a plurality of lines (112a, 112b; 510) of a communication system, comprising: Separating a first signal portion transmitted in a first direction of a signal present on the first line; Generating a first signal representing the first signal component; Generating a second signal by delaying the first signal by a first predetermined value; selectively filtering a third signal based on a signal present on a second line of the plurality of lines to generate a fourth signal; Combining the second signal and the fourth signal to produce a conditioned signal; and Control the adjustable filtering based on the processed signal. Procedure according to Claim 1 , in which the separation of the signal present on the first line comprises a separation of the signal present on the first line into a receive signal and transmit signal by means of a hybrid circuit, the first signal representing a received signal component. Procedure according to Claim 1 or 2 in which the communication system is a duplex telecommunications system and the plurality of lines is a plurality of two-wire lines of a cable bundle. Procedure according to one of the Claims 1 to 3 , wherein the signal present on the first line is an analog signal and the first signal is a digital signal. Procedure according to one of the Claims 1 to 4 , wherein before the separation of the first signal portion comprises a frequency-dependent separation of the signal present on the first line into a second and third signal portion, and the separation of the first signal portion comprises a separation of a signal portion of the second signal portion depending on a transmission direction on the first line. Procedure according to Claim 5 , in which the second signal component has frequencies that are higher than frequencies of the first signal component. Procedure according to Claim 5 or 6 , in which the processed signal and the third signal component are combined to form a combined processed signal. Procedure according to one of the Claims 1 to 7 The method further comprises: adjustable filtering of fifth signals, each based on signals that are present on further ones of the plurality of lines, for generating sixth signals; and combining the second, fourth and sixth signals to produce the conditioned signal. Procedure according to one of the Claims 1 to 8th , whereby the adjustable filtering comprises only digital filtering. Procedure according to one of the Claims 1 to 9 , further comprising: generating an echo cancellation signal; and combining the second signal, the fourth signal, and the echo cancellation signal to generate the conditioned signal. Procedure according to one of the Claims 1 to 10 , in which, for each line of the plurality of lines, a preparation is applied to this line Signals corresponding to the Claims 1 to 10 is carried out. Device for processing a signal which is present on a first line of a plurality of lines (112a, 112b; 510) of a communication system, having the following features: means (114; 710) for separating a first signal portion transmitted in a first direction of a signal present on the first line and for generating a first signal which represents the first signal portion; means (116; 714) for generating a second signal by delaying the first signal in time by a first predetermined value; an adjustable filter (124; 622) for filtering a third signal based on a signal present on a second line of the plurality of lines to produce a fourth signal; a combination circuit (118; 718) for combining the second signal and the fourth signal to generate a conditioned signal; wherein the adjustable filter has a control input (124a; 622a) which is coupled to an output (118c; 716a) of the combination circuit (118; 718) for controlling the adjustable filter based on the processed signal. Device after Claim 12 The device (114) for separating a first signal component comprises a first hybrid circuit (710). Device after Claim 13 , further comprising a second hybrid circuit (726), a transmission connection (726b) of the second hybrid circuit (726) being coupled to a receiving terminal (710c) of the first hybrid circuit (710), and a receiving terminal (726c) of the second hybrid circuit (726) the combination circuit (718) is coupled. Device after Claim 12 to 14 , wherein the communication system is a telecommunications system (500) and the plurality of lines (510) is a plurality of two-wire lines of a cable bundle. Device according to one of the Claims 12 to 15 , further comprising: an A / D converter (712) for generating the first signal as a digital signal based on the separated signal component; and a D / A converter (620) for converting the conditioned signal into an analog conditioned signal. Device according to one of the Claims 12 to 16 , further comprising a first splitter filter (610), the first splitter filter having a first connection (610a) which can be coupled to a section of the first line, a second connection (610c) which is coupled to the device for time delay, and one having a third connection (610b), and the device further comprising a second splitter filter (614), the second splitter filter (614) having a first connection (614c) which is coupled to the combination circuit (716), and a second connection (614b) which is coupled to the third connection (610b) of the second splitter filter (610). Device according to one of the Claims 12 to 17 , wherein the device has a first tap (734) for tapping the first signal, the first tap being able to be coupled to a further adjustable filter, the further adjustable filter being connected up to process the second signal present on the second line. Device according to one of the Claims 12 to 18 , further comprising: a plurality of further adjustable filters, each with an input for applying fifth signals, each based on signals that are present on further lines of the plurality of lines, and an output for generating sixth signals; wherein the combination circuit (718) is further configured to combine the second, the fourth signal and the sixth signals. Device according to one of the Claims 12 to 19 , the adjustable filter being an exclusively digital filter. Device according to one of the Claims 12 to 20 , further comprising: means (730) for generating an echo cancellation signal; the combination circuit (716) being configured to combine the second signal, the fourth signal, and the echo compensation signal. Device according to one of the Claims 12 to 21 , further comprising a second tap (732) for tapping a signal component transmitted on the first line in a second direction opposite to the first direction, the second tap (732) having a further adjustable filter for processing the second signal present on the second line can be coupled.

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