Granted Patent B2

US 7,486,788 · App. 10/617,310 · Granted Feb 3, 2009

Abstract

Claims (33)

1. A transceiver for a transmission and reception signal which can be transmitted via a signal line having a particular line impedance, comprising:

a) a line driver for driving a transmission signal via the signal line, the line driver having a synthesized output impedance;

b) a programmable analog echo cancellation filter for signal suppression for an echo signal brought about by the transmission signal;

c) a hybrid circuit for connecting said analog echo cancellation filter to the signal line, the hybrid circuit comprising:

a first two-pole connection connected to the output of the line driver,

a second two-pole connection for connection to the signal line,

a third two-pole connection connected to the analog echo cancellation filter,

series resistors being connected, in series with the line impedance of the signal line, between the first two-pole connection and the second two-pole connection,

a first and a second series-connected crosscoupling resistor respectively connected between the first two-pole connection and the second two-pole connection,

wherein the third two-pole connection of the hybrid circuit for connecting the echo cancellation filter is tapped off between the series-connected crosscoupling resistors, and

wherein the resistance values of the resistors connected in the hybrid circuit satisfy the following equation:

R2

=

R3

·

R

SYN

R

⁢

⁢

1

+

R

SYN

Where R 1 is the resistance value of the series resistors, R 2 is the resistance value of the first crosscoupling resistor, and R 3 is the resistance value of the second crosscoupling resistor, and where R SYN is the synthesized output impedance of the line driver,

d) a reception filter for filtering a signal received via the signal line; and

e) a subtraction circuit which subtracts from the filtered output signal of the reception filter the transmission signal simulated by the echo cancellation filter to generate a reception signal liberated of the echo signal.

2. The transceiver as claimed in claim 1 , wherein the transfer function of the echo cancellation filter has a programmable pole point and a programmable zero point.

3. The transceiver as claimed in claim 1 , wherein the line driver is of differential design.

4. The transceiver as claimed in claim 1 , wherein the synthesized output impedance of the line driver is real.

5. The transceiver as claimed in claim 1 , wherein the resistors connected in the hybrid circuit are real resistors.

6. The transceiver as claimed in claim 1 , wherein the hybrid circuit is of symmetrical design.

7. The use of the transceiver as claimed in claim 1 for a broadband communication system, particularly for an xDSL broadband communication system.

Assignments (9)