DE102004014969B4 - Broadband system e.g. asymmetric digital subscriber line system, for e.g. subscriber telephone exchange, has adaptation device adding generated compensation signal to broadband signal to compensate distortion of sinusoidal signaling signal - Google Patents

Abstract

The system has an adaptation device (2) for generation of a compensation signal (KS) from a received broadband signal (eBS) which is superimposed with an amplified sinusoidal signaling signal of a audio system (3). The adaptation device adds the generated compensation signal to a broadband signal (sBS) to compensate a distortion of the sinusoidal signaling signal arising during amplification of the sinusoidal signal. - An INDEPENDENT CLAIM is also included for a subscriber telephone exchange with a broadband system.

Description

The The invention relates to a broadband system with generation of a compensation signal for distortion compensation of an amplified sinusoidal signaling signal and a local exchange with such a broadband system.

The Technical field of the invention relates to the transmission of speech signals in a baseband and the simultaneous transmission of data signals in a higher Frequency band over a common subscriber line. In simultaneous transmission of voice signals and data signals over a common subscriber line there is the problem that within an integrated data / voice local exchange Interference between an amplified signaling signal associated with the speech signal and the data signal. A local exchange consists essentially of a language system (e.g., telephone) and a wideband system (e.g., ADSL system). Problematic are the signaling signals with a high signal level (for example the TTX (Teletex) signal), which at a frequency of 12 or 16 kHz is up to 5 Vrms on the subscriber line, and whose higher harmonic harmonics caused by nonlinear properties at the reinforcement of the signals through the subscriber line circuit (SLIC - Subscriber Line Interface Circuit) of the speech system. On the one hand to disturb the harmonic harmonics the upstream signals of the ADSL data transmission (Asymmetric Digital Subscriber Line). On the other hand causes the fundamental high level of the signaling signal that the AD converter in the receiving part of the broadband system overdrives. These problems Experience both Integrated Video Data (IVD) solutions and DSLAM solutions, which by means of splitter filter high order with the language system POTS system (POTS = Plain Old Telephone System) are connected.

The Fundamental wave of the distorted amplified Signaling signal or the TTX signal can by steep-edged, passive LC filters (high-pass and low-pass filters) can be reduced. The negative influence of harmonic harmonics of the amplified signaling signal is through appropriate increase minimized the so-called margins of the affected carrier. An increase in the Margins means an increase the reserve for the signal-to-noise ratio. Both measures But at the expense of the data rate and can sometimes lead to the connection abort to lead.

The publication US 6,157,680 A describes a method and apparatus for adaptively canceling non-linear, band-external acoustic distortions within a DSL device.

The publication US 6,570,514 B1 discloses a compensator for compensating for linearity errors in a device wherein a base signal and linearity error distortion signals are generated. The compensator comprises an interpolator for generating an interpolated signal, an exponentiator for generating an interpolated compensation signal and a phase shifter. The phase shifter shifts a phase between the fundamental signal and the interpolated compensation signal such that linearity error distortion signals are canceled and the fundamental signal is maintained.

The publication US 6,545,535 B2 describes a predistortion technique by means of high pass filtering so that distortion compensation by the predistortion specific frequencies for which further distortion compensation is required is performed.

The post-published publication DE 103 55 697 A1 shows a circuit for compensation of harmonics of a sinusoidal signaling signal. The circuit has an amplification unit which amplifies the sinusoidal signaling signal, resulting in N harmonics with associated phase differences to the sinusoidal signaling signal and associated amplitudes due to a non-linear amplification by the amplification unit and thus a distorted signaling signal is formed. Furthermore, the circuit has an adaptation unit which calculates the N phase differences and the N amplitudes for a compensation signal from the feedback signal, and a signaling generator which generates a compensation signal in dependence on the N calculated phase differences and the N calculated amplitudes non-linear amplification of the sinusoidal signaling signal and the compensation signal by the amplification unit, the compensation signal compensates the N harmonic harmonics of the amplified sinusoidal signaling signal.

The object of the present invention is therefore to provide a broadband system for distortion compensation of an amplified sinusoidal signaling signal, so that probably the fundamental disturbing the data stream as well as harmonics of the amplified sinusoidal signaling signal can be compensated.

According to the invention Asked task by a broadband system with the features of claim 1 and by a local exchange with the features of claim 13.

The The idea underlying the present invention consists essentially in it, a broadband system for sending and receiving broadband signals with an adaptation device for the adaptive generation of a compensation signal the received wideband signal, which with an amplified sinusoidal signaling signal superimposed on a couplable with the wideband system voice system is to provide, wherein the adaptation device to the broadband signal to be transmitted the generated compensation signal adds that which occurs during amplification distortion of the sinusoidal Signaling signal compensated.

The inventive broadband system provides thus ensuring that the AD converter is in the receiving part of the broadband system due to the compensation of the distortion of the fundamental wave of the amplified signaling signal not overdriven.

One Another advantage of the invention is that broadband signals or ADSL data in a higher Frequency band without interference harmonic harmonics of the amplified signaling signal transferable are.

advantageously, is the generation of the compensation signal independent of the linkable language system or POTs system, so that the language system, which with the wideband system to a local exchange or to an IVD solution can be coupled, can be any of any manufacturer.

One Another advantage is that the adaptation loop for adaptive generation the compensation signal is short, since this is entirely in the broadband system is integrated. The language system, on the other hand, becomes adaptive generation the compensation signal is not used.

advantageous Refinements and developments of the invention will become apparent the dependent claims and the description with reference to the drawings.

According to one preferred embodiment of the invention has the adaptation device a bandpass filter, which consists of the received, superimposed with the amplified signaling signal wideband signal a distorted fundamental of the distorted amplified sinusoidal signaling signal filters out.

According to one Another preferred embodiment has the adaptation device an adjustable signaling generator for providing an expanded one Signalisie approximately signal, wherein the extended signaling signal the fundamental and the harmonics of the signaling signal includes.

One Advantage of this development is that by providing the Fundamental and the harmonics of the signaling signal within the adaptation device, the broadband system independent of a speech system can generate the compensation signal. Of Furthermore, the signaling generator is dependent on the frequency used of the TTX signal, for example 12 or 16 kHz, adjustable.

According to one Another preferred embodiment has the adaptation device a compensation signal generator having the distorted fundamental of the distorted amplified sinusoidal Signaling signal, the extended signaling signal and a distance signal representing a distance between the received wideband signal and indicates a detected noiseless broadband signal, receives and which by means of the received signals, the compensation signal generated.

According to one Another preferred embodiment has the adaptation device a summation device for superposition of the broadband signal to be transmitted and the compensation signal.

According to one Another preferred embodiment determines the compensation signal generator the received distorted fundamental of the amplified sinusoidal signaling signal a phase difference and an amplitude difference to the fundamental the signaling signal.

According to one Another preferred embodiment determines the compensation signal generator the distance signal N phase differences and N amplitude differences to the harmonics of the signaling signal.

According to one Another preferred embodiment generates the compensation signal generator from the extended signaling signal, the phase difference and the amplitude difference to the fundamental and the N phase differences and N amplitude differences from the harmonics, the compensation signal.

According to one Another preferred development is the broadband system a broadband modem for transmit / receive and modulate / demodulate the broadband signals and by a data pump for the detection of received wideband signals, to generate the distance signal and for transmission of the broadband signal to be sent to the broadband modem.

According to one Another preferred development, the broadband modem has a Receiving device, which a first low-pass filter for band limitation the signals to be received and a first AD converter for conversion having received signals from analog to digital signals.

According to one Another preferred development, the broadband modem has a Transmitter on which a first DA converter for conversion the signals to be sent from digital to analogue signals, a second one Low-pass filter for limiting the band of the signals to be transmitted and an amplification device for reinforcement having the signals to be transmitted.

According to one Another preferred embodiment, the data pump generates the Distance signal in the detection of the received broadband signal by means a signal-to-noise ratio of the received wideband signal or by means of a decision distance between the received wideband signal and the detected noiseless wideband signal.

According to one Another preferred development is the broadband modem exclusively the amplifying device integrated.

One Advantage of this preferred development is that so that the Adaptation device for generating the compensation signal within the broadband modem is integrated.

The Invention will be described below with reference to the schematic figures specified embodiments explained in more detail. It shows:

1 a block diagram of a preferred embodiment of a broadband system according to the invention; and

2 a block diagram of a preferred embodiment of the subscriber exchange according to the invention.

In all figures are the same or functionally identical elements - if otherwise stated - with the same reference numerals have been provided.

Even though the present invention with reference to broadband systems and local exchanges, she is on it not limited but on diverse Way used.

1 shows a block diagram of a preferred embodiment of a broadband system according to the invention.

The broadband system 1 has a broadband modem 7 for transmitting / receiving and modulating / demodulating the broadband signals eBS, sBS and a data pump 8th for detecting the received broadband signals eBS, for generating the distance signal DS and for transmitting the broadband signal sBS to be transmitted to the broadband modem 7 on.

The broadband modem 7 has a receiving device 9 on which a first low-pass filter 10 for limiting the band of the signals to be received, in particular of the wideband signal eBS superimposed on the distorted amplified signaling signal verSS, and a first AD converter 11 for converting the received signals from analog to digital signals.

The broadband signal eBS superimposed on the distorted signaling signal verSS firstly reaches the data pump 8th as well as a bandpass filter 4 the adaptation device 2 transfer.

Next to the bandpass filter 4 has the adaptation device 2 a signaling generator 5 , a compensation signal generator 6 and a summation device 13 on.

The bandpass filter 4 the adaptation device 2 filters out of the received wideband signal eBS superimposed with the amplified signaling signal verSS a distorted fundamental vibration verSS of the distorted amplified sinusoidal signaling signal verSS and transmits it to the compensation signal generator 6 ,

The signaling generator 5 provides an enhanced signaling signal and transmits it to the compensation signal generator 6 , wherein the extended signaling signal erwSS comprises the fundamental oscillation GS and the harmonics OS of the signaling signal SS. The signaling generator 5 is adjustable depending on the used frequency of the signaling signal SS or the TTX signal.

The data pump 8th detected from the emp broadband signal eBS catch a noise-free wideband signal detBS. Due to the noise on the lines, there is a distance between the detected wideband signal detBS and the received wideband signal eBS. The data pump generates by means of the signal-to-noise ratio of the received broadband signal eBS or by means of a decision distance between the received broadband signal eBS and the detected noise-free broadband signal detBS at the decision maker or slicer 8th a distance signal DS and transmits this distance signal DS to the compensation signal generator 6 ,

The compensation signal generator 6 preferably receives the distorted fundamental shrink verGS of the distorted amplified sinusoidal signaling signal verSS from the bandpass filter 4 , the extended signaling signal from the signaling generator 5 and the distance signal DS from the data pump 8th , By means of the received signals, the compensation signal generator generates 6 the compensation signal KS.

In the process, the compensation signal generator determines 6 First, from the received distorted fundamental oscillation verGS of the amplified sinusoidal signaling signal verSS a phase difference φ _GS and an amplitude difference A _GS to the fundamental oscillation GS of the signaling signal SS. Further determines the compensation signal generator 6 from the distance signal DS N phase differences φ _OS and N amplitude differences A _OS to the harmonics OS of the signaling signal SS.

Preferably, the compensation signal generator generates 6 the compensation signal KS from the expanded signaling signal erwSS, the phase difference φ _GS and the amplitude difference A _GS to the fundamental oscillation GS and the N phase differences φ _OS and N amplitude differences A _OS to the harmonics of the signaling signal SS.

In addition to the detection of the received broadband signal eBS and the generation of the distance signal DS has the data pump 8th Next is the function to send the broadband signal sBS to the broadband modem 7 transferred to.

The summation device 13 the adaptation device 2 superimposed on the broadband signal to send sBS and the compensation signal KS and transmits the transmitted to the compensation signal KS superimposed broadband signal sBS to the transmitting device 12 of the broadband modem 7 ,

The transmitting device 12 has a first DA converter 14 for converting the signals to be transmitted from digital to analog signals, a second low-pass filter 15 for limiting the band of the signals to be transmitted and an amplification device 16 or a line driver for amplifying the signals to be transmitted.

The reinforcing device 16 and thus the broadband system 1 have as output to be sent, superimposed with the compensation signal KS broadband signal sBS.

2 shows a block diagram of a preferred embodiment of the subscriber exchange according to the invention coupled to a subscriber terminal.

The local exchange 17 is via a subscriber line 19 with a subscriber terminal 22 coupled. The local exchange is preferably an integrated voice / data circuit and the subscriber terminal 22 preferably comprises a voice terminal, eg a telephone, and a data terminal, for example an ADSL modem.

The local exchange 17 indicates one 1 described broadband system 1 , a separation filter 18 and a language system 3 on.

The separation filter 18 has the function, the broadband system 1 and the language system 3 in such a way that wideband signals eBS, sBS or ADSL signals and speech signals SpS or POTs signals of the speech system 3 on a single subscriber line 19 are transferable.

Preferably, the separation filter 18 a splitter filter of high order.

The broadband system 1 points as in 1 and the associated description, as an input with a distorted amplified signaling signal verSS superimposed broadband signal eBS. The output is the broadband system 1 a compensation signal KS added to the broadband signal sBS to be sent which leads to the separation filter 18 be transmitted.

The language system 3 has a telephone device 20 and a subscriber line circuit 21 or a SLIC circuit.

The telephone device 20 generates a voice signal SpS and transmits it to the subscriber line circuit 21 , The subscriber line circuit 21 generates an associated signaling signal SS to the speech signal SpS and amplifies these two signals by means of an amplification unit of the subscriber line circuit 21 , Due to non-linear characteristics of the amplification unit of the subscriber line circuit 21 a distorted amplified signaling signal verSS is formed to the speech signal SpS. The subscriber line circuit 21 transmits the amplified signals, the speech signal SpS and the signaling signal verSS to the separation filter 18 ,

In case of transmission of signals from the local exchange 17 to the subscriber terminal 22 has the separation filter 18 the broadband signal sBS to be transmitted as input, the compensation signal KS, the speech signal SpS and the distorted amplified signaling signal verSS.

The input signals are superimposed in such a way that the compensation signal KS compensates the distortion of the distorted amplified signaling signal verSS, thereby producing an amplified signaling signal SS, which is transmitted via the subscriber line 19 to the subscriber terminal 22 is transmitted.

About the separation filter 18 the wideband signal sBS to be transmitted, the speech signal SpS and the amplified, non-distorted signaling signal SS are sent to the subscriber terminal 22 transfer.

Furthermore, it is located on the subscriber line 19 the wideband signal eBS to be received, which is sent by the subscriber terminal 22 to the separation filter 18 the local exchange 17 is transmitted.

The signals on the subscriber line 19 advantageously do not overlap.

Even though the present invention above based on preferred embodiments It is not limited to this, but in many ways and modifiable. For example, the broadband system according to the invention within an IVD solution (Integrated Voice Data System) or integrated in a DSLAM system be.

1

Broadband system

2

adaptation device

3

language system

4

Bandpass filter

5

Signaling generator

6

Compensation signal generator

7

Broadband Modem

8th

data pump

9

receiver

10

first Low Pass Filter

11

first ADC

12

transmitting device

13

Summing means

14

first DA converter

15

second Low Pass Filter

16

reinforcing device

17

Local exchange

18

separating filter

19

Local loop

20

telephone device

21

Subscriber line interface circuit (SLIC)

22

Subscriber terminal

BS

Broadband signal

sBS

to sending broadband signal

eBS

received Broadband signal

SS

signaling signal

verSS

distorted signaling signal

KS

compensation signal

verGS

distorted fundamental

erwSS

expanded signaling signal

GS

fundamental

OS

harmonics

DS

distance signal

detBS

detected Broadband signal

φGS

phase difference to the fundamental

A _GS

amplitude difference to the fundamental

φ _OS

phase differences to the harmonics

A _OS

amplitude differences

Claims (14)

Broadband system ( 1 ) for transmitting and receiving wideband signals (sBS, eBS) with an adaptation device ( 2 ) for adaptively generating a compensation signal (KS) from the received broadband signal (eBS), which is provided with an amplified sinusoidal signaling signal (verSS) of one with the wideband system ( 1 ) couplable speech system ( 3 ) is superimposed, wherein the adaptation device ( 2 ) to the broadband signal (sBS) to be sent, the generated compensation signal (KS), which compensates for a distortion occurring during the amplification of the sinusoidal signaling signal (verSS). Broadband system according to claim 1, characterized in that the adaptation device ( 2 ) a bandpass filter ( 4 ), which filters out a distorted fundamental (verGS) of the amplified sinusoidal signaling signal (verSS) from the received wideband signal (eBS) superimposed with the amplified signaling signal (verSS). Broadband system according to claim 1, characterized in that the adaptation device ( 2 ) an adjustable signaling generator ( 5 ) for providing an extended signaling signal (erwSS), wherein the extended signaling signal (erwSS) the fundamental (GS) and the harmonics (OS) of the signaling signal (SS). Broadband system according to one or more of the preceding claims, characterized in that the adaptation device ( 2 ) a compensation signal generator ( 6 ), which indicates the distorted fundamental (verGS) of the amplified sinusoidal signaling signal (verSS), the extended signaling signal (erwSS), and a distance signal (DS) indicating a distance between the received wideband signal (eBS) and a detected noiseless wideband signal (detBS) , and which generates the compensation signal (KS) by means of the received signals. Broadband system according to one or more of the preceding claims, characterized in that the adaptation device ( 2 ) a summation device ( 13 ) for superposition of the broadband signal (sBS) to be transmitted and the compensation signal (KS). Broadband system according to one or more of the preceding claims, characterized in that the compensation signal generator ( 6 ) from the received distorted fundamental (verGS) of the amplified sinusoidal signaling signal (vrrSS) a phase difference (φ _GS ) and an amplitude difference (A _GS ) to the fundamental (GS) of the signaling signal (SS) determined. Broadband system according to one or more of the preceding claims, characterized in that the compensation signal generator ( 6 ) from the distance signal (DS) N phase differences (φ _OS ) and N amplitude differences (A _OS ) to the harmonics (OS) of the signaling signal (SS) determined. Broadband system according to one or more of the preceding claims, characterized in that the compensation signal generator ( 6 ) from the extended signaling signal (erwSS), the phase difference (φ _GS ) and the amplitude difference (A _GS ) to the fundamental (GS) and the N phase differences (φ _OS ) and N amplitude differences (A _OS ) to the harmonics (OS) Compensation signal (KS) generated. Broadband system according to one or more of the preceding claims, characterized in that the broadband system ( 1 ) by a broadband modem ( 7 ) for transmitting / receiving and modulating / demodulating the broadband signals (eBS, sBS) and by a data pump ( 8th ) for detecting the received broadband signals (eBS), for generating the distance signal (DS) and for transmitting the broadband signal (sBS) to be transmitted to the broadband modem ( 7 ) is trained. Broadband system according to one or more of the preceding claims, characterized in that the broadband modem ( 7 ) a receiving device ( 9 ) having a first low-pass filter ( 10 ) to the band boundary of the signals to be received and a first AD converter ( 11 ) for converting the received signals from analog to digital signals. Broadband system according to one or more of the preceding claims, characterized in that the broadband modem ( 7 ) a transmitting device ( 12 ), which has a first DA converter ( 14 ) for converting the signals to be transmitted from digital to analog signals, a second low-pass filter ( 15 ) for limiting the band of the signals to be transmitted and an amplification device ( 16 ) for amplifying the signals to be transmitted. Broadband system according to one or more of the preceding claims, characterized in that the data pump ( 8th ) generates the distance signal (DS) in the detection of the received broadband signal (eBS) by means of a signal-to-noise ratio of the received wideband signal (eBS) or by means of a decision distance between the received wideband signal (eBS) and the detected noise-free wideband signal (detBS). Broadband system according to one or more of the preceding claims, characterized in that the broadband modem ( 7 ) excluding the reinforcing device ( 16 ) is integrated. Local exchange ( 17 ) with a broadband system ( 1 ) according to any one of the preceding claims; with a separating filter ( 18 ), which the broadband system ( 1 ) and a language system ( 3 ) such that wideband signals (eBS, sBS) and speech signals (SpS) of the speech system ( 3 ) on a single subscriber line ( 19 ) are transferable; and with the language system ( 3 ), which by means of a subscriber line circuit ( 21 ) to a speech signal (SpS) generates a signaling signal (SS) and amplifies the speech signal (SpS) and the associated signaling signal (SS), wherein due to non-linear properties in the amplification of a distorted amplified signaling signal (verSS) is formed, which broadband signals (eBS , sBS) on the common subscriber line ( 19 ) disturbs.