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US 8,027,279 B2Granted
Echo cancellation
AssigneeLantiq Deutschland GmbH
InventorsMartin Clara, Christian Fleischhacker, Wolfgang Klatzer, Tina Thelesklav
Life of this patent
Estimating the term…
Abstract
Embodiments related to echo compensation have been described and depicted.
Claims16
An echo cancellation circuit, comprising:
- a digital filter;
- and
- a digital-to-analog converter, comprising:
- a digital input coupled to the digital filter to receive a digital signal representing digital information of an echo signal,
- a control signal input to receive a control signal, and
- at least one conversion element to generate an analog output signal based on the digital signal,
- wherein the at least one conversion element is controllable by the control signal, and
- wherein the at least one conversion element comprises a programmable current cell operable to program the output current of the cell based on the control signal.
5 more elements
A method comprising:
- transmitting a first signal over a communication channel;
- generating a digital representation of an echo of the first signal;
- generating an analog second signal by converting the digital representation of the echo signal, the generating being performed by a digital-to-analog converter;
- controlling the converting of the digital representation based on a third signal;
- receiving a fourth signal transmitted over the communication channel;
- generating an echo compensated signal by combining the second signal and a fifth signal representing the fourth signal.
3 more elements
A transceiver circuit, comprising:
- a transmit path comprising a first output to transmit a first signal;
- a receive path comprising a first input to receive a second signal;
- an echo cancellation path;
- first circuitry to combine the echo cancellation path with the receive path, the first circuitry comprising:
- a virtual ground node of a variable gain amplifier arranged in the receive path,
- a first branch to connect the virtual ground node with the first input,
- a second branch to connect the virtual ground node with an input of the variable gain amplifier, and
- a third branch to connect the echo cancellation path with the virtual ground node;
- and
- a digital-to-analog conversion circuit arranged in the echo cancellation path, the digital-to-analog conversion circuit comprising:
- an input coupled to the transmit path to receive a digital signal and an output coupled to the virtual ground node,
- a first digital input for receiving the digital signal,
- a second input to receive a control signal, and
- a plurality of current cells, each of the current cells being programmable dependent on the control signal,
- wherein the digital-to-analog conversion circuit is to provide an output current dependent on the digital signal and the control signal.
12 more elements
An echo cancellation circuit, comprising:
- a digital filter;
- a controller to set a first digital gain of the digital filter;
- first circuitry to convert digital information provided by the digital filter to an analog signal;
- second circuitry to set a second analog gain to compensate the digital gain,
- wherein the second circuitry is integrated in the first circuitry, and
- wherein the second circuitry comprises programmable current cells provided in the first circuitry.
3 more elements
Dependencies are inferred from the claim text.