US 7,069,165 B2 · Method and arrangement for signal loop test

Abstract

The invention refers to single-ended test of a loop with the aid of a transceiver, wherein an input impedance (Zin(ƒ)) of the loop is generated. The transceiver has a digital part, a codec and an analog part and is connected to the loop. With the aid of a transmitted and a reflected broadband signal (vin, vout) an echo transfer function Hecho(ƒ)=V(f)out/Vin(f) is generated, which also can be expressed as H echo ⁡ ( f ) = H ∞ ⁡ ( f ) ⁢ Z in ⁡ ( f ) + Z h0 ⁡ ( f ) Z in ⁡ ( f ) + Z hyb ⁡ ( f ) . Here Zh0(ƒ), Zhyb(ƒ) and H∞(ƒ) are model values for the transceiver. In a calibration process a test transceiver, with the same type of hardware as the transceiver, is connected to known impedances, replacing the loop. Hecho(ƒ)=V(f)out/Vin(f) is generated for the known impedances and the model values are generated and are stored in a memory in the transceiver. The stored model values are then used when the input impedance (Zin(ƒ)) for the loop is generated after a measurement of the broadband signal (Vin, vout) is performed.

Claims12

Dependent claims

A Method in single-ended test of a signal line, the method comprising the steps of:

Selecting a test transceiver;
Connecting impedances each of a predetermined value to a line connection of the test transceiver;
generating, in a calibration process, calibration values for the test transceiver with the aid of said impedances and test signals (vtin, vtout),
generating for the test transceiver frequency dependent echo transfer functions (Hecho(ƒ)) utilizing at least three impedances;
generating test transceiver model values (Zh0(ƒ), Zhyb(ƒ), H∞(ƒ)) with the aid of said echo transfer functions (Hecho(ƒ)) and the corresponding impedance values, said model values including an echo transfer function (H∞(ƒ)) for the test transceiver with open line connection, a test transceiver impedance value (Zhyb(ƒ)) as seen from the line side and a product (Zh0(ƒ)) of said transceiver impedance value (Zhyb(ƒ)) and an echo transfer function (H0(f)) for the test transceiver with shortcut line connection;
selecting a transceiver for communication purposes of the same type of hardware as said test transceiver;
and
storing the transceiver model values (Zh0(ƒ), Zhyb(ƒ), H∞(ƒ)) in said transceiver for communication purposes.

5 more elements

An arrangement in single-ended test of a signal line, the arrangement comprising:

A first transceiver;
impedances of each a predetermined value to be connected to a line connection of the first transceiver;
a measurement device for generating, in a calibration process, calibration values for the first transceiver with the aid of said impedances and test signals (vtin, vtout),
the measurement device being arranged to generate a frequency dependent echo transfer function (Hecho(ƒ)), for the first transceiver utilizing at least three of said impedances;
the measurement device being further arranged to generate first transceiver model values (Zh0(ƒ), (Zhyb(ƒ), H∞(ƒ)) with the aid of said echo transfer function (Hecho(ƒ)) and the corresponding impedance values, said model values including an echo transfer function (H∞(ƒ)) for the first transceiver with open line connection, a first transceiver impedance value (Zhyb(ƒ)) as seen from the line side and a product of said first transceiver impedance value (Zhyb(ƒ)) and an echo transfer function (H0(f)) for the first transceiver with shortcut line connection;
a second transceiver, for communication purposes, of the same type of hardware as said first transceiver;
wherein said second transceiver for communication purposes has
a memory for storing the first transceiver model values (Zh0(ƒ), Zhyb(ƒ), H∞(ƒ)).

5 more elements

An arrangement in single-ended test of a signal line, the arrangement comprising:

means for selecting a test transceiver;
means for connecting impedances of each a predetermined value to a line connection of the test transceiver;
means for generating, in a calibration process, calibration values for the test transceiver with the aid of said impedances and test signals (vtin, vtout),
means for generating for the test transceiver frequency dependent echo transfer functions (Hecho(ƒ)) utilizing at least three impedances;
and
means for generating test transceiver model values (Zh0(ƒ), Zhyb(ƒ), H∞(ƒ) with the aid of said echo transfer functions (Hecho(ƒ)) and the corresponding impedance values, said model values including an echo transfer function (H∞(ƒ)) for the test transceiver with open line connection, a test transceiver impedance value (Zhyb(ƒ)) as seen from the line side and a product (Zh0(ƒ)) of said test transceiver impedance value (Zhyb(ƒ)) and an echo transfer function (H0(f)) for the test transceiver with shortcut line connection;
means for selecting a transceiver for communication purposes of the same type of hardware as said test transceiver;
and
means for storing the test transceiver model values (Zh0(ƒ), Zhyb(ƒ), H∞(ƒ)) in said transceiver for communication purposes.

6 more elements

Dependencies are inferred from the claim text.

Method and arrangement for signal loop test

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Method and arrangement for signal loop test

Life of this patent

Abstract

Claims12