Infineon Technologies Ag

Lantiq Deutschland Gmbh

Lantiq Beteiligungs Gmbh & Co. Kg

David Schwingshackl

Alberto Canella

Joerg Hauptmann

Gerhard Paoli

Dietmar Straeussnigg

Christian Jenkner

Bernhard Zojer

Gerhard Noessing

Herbert Zojer

Peter Pessl

Gernot Kubin

Christian Schranz

Gerhard N&ouml;ssing

Herbert Zoler

Implementations related to echo cancellation are depicted and described herein.

Echo cancellation

A signal generator is disclosed that generates a test signal to be applied to a first and second wire of a subscriber line. The signal generator is configured to generate the test signal at the first and second test signal outputs in a first time section such that a first potential at the first test signal output is changed from a first value to a second value and a second potential at the second test signal output is maintained constant at least during the change of the first potential. The signal generator is further configured to generate the test signal during a second time section such that the first potential at the first output and the second potential at the second output are oscillating with a predetermined frequency.

Line testing

A method for creating a form of a non-linear filter suitable for reducing a computational complexity is proposed. The filter is resolved into polyphase components in such a way that the polyphase components can be interchanged with a conversion of the sampling rate of a signal to be sent to the filter or of a signal to be emitted by the filter. Corresponding filters and filter arrangements are also proposed. In this way, a computational complexity for calculating the signal to be emitted by the filter can be significantly simplified. The invention can be used in echo compensation.

Method for reducing a computational complexity in non-linear filter arrangements as well as corresponding filter arrangements

The invention provides a transmission apparatus () for transmission of electrical signals between a line driver (), which is connected to a transmission line (), and a switching center (), having an analog feedback device () for coarse setting of a line voltage level () on the transmission line (), and a digital feedback device (), which is coupled to the analog feedback device () and has a feedback filter device (), designed such that a filter input signal () can be converted to a filter output signal () at a rate which is lower than the sampling rate (f) of an analog/digital converter ().

Transmission apparatus with variable impedance matching

In the line terminating device, which is provided for transmitting and receiving narrowband low-frequency voice signals and broadband data signals at a higher frequency, the analog reception path is subdivided into two separate analog paths () for voice and data using a balance filter (), which is used for data signal echo cancellation. In the transmission direction, the voice signal path and the data signal path are separated in the digital part by means of digital filters (). The invention is used for voice and data signal separation in xDSL methods, for example, ADSL.Lite.

Line termination device for a telephone subscriber line

Method for measuring a load impedance (Z ) of a load circuit which is connected to an SLIC circuit ( ) of an analog terminal connection of a terminal device, having the following steps: specifically a digital toll signal (x ) is generated by means of a Codec circuit ( ) connected to the SLIC circuit ( ), said toll signal (x ) being converted into an analog toll signal; the analog toll signal is output by the SLIC circuit ( ) to the load circuit; an analog voltage which is brought about at the terminal connection ( ) of the terminal device of the SLIC circuit ( ) via the analog toll signal is sensed; the digital toll signal (x ) is filtered by means of an adaptive filter ( ) which is provided in the Codec circuit ( ) and has adjustable filter coefficients (g , g ) for generating a filtered digital comparison signal (y ) which is converted into an analog comparison voltage (U ); the filter coefficients (g , g ) of the adaptive filter ( ) are adjusted until the analog comparison voltage (U ) and the analog voltage (U ), brought about by the analog toll signal, at the terminal connection ( ) of the terminal device are the same; the complex load impedance (Z ) of the load circuit is calculated as a function of the set filter coefficients (g , g )

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Villach, Austria

David Schwingshackl