System architecture for supporting digital pre-distortion and full duplex in cable network environments

Patent metadata

Field	Value
Publication number	US-10797750-B2
Application number	US-201615352445-A
Country	US
Kind code	B2
Filing date	Nov 15, 2016
Priority date	Feb 24, 2016
Publication date	Oct 6, 2020
Grant date	Oct 6, 2020

Abstract

An example apparatus for supporting digital pre-distortion (DPD) and full duplex (FDX) in cable network environments is provided and includes a first path for signals being transmitted out of the apparatus, a second path for signals being received into the apparatus, a DPD actuator located on the first path, an amplifier located on the first path, an echo cancellation (EC) actuator located on the second path, and a data interface including a plurality of channels connecting the apparatus to a signal processor. DPD coefficients, EC coefficients and delay parameters are provided over the data interface from the signal processor to the apparatus. The DPD actuator predistorts signals on the first path using the DPD coefficients compensating for distortions introduced by the amplifier, and the EC actuator reduces interferences in signals on the second path using the EC coefficients and the delay parameters, facilitating FDX communication by the apparatus.

First claim

What is claimed is:

1. An apparatus, comprising:
a first path for first signals being transmitted out of the apparatus;
a second path for second signals being received into the apparatus;
a digital pre-distortion (DPD) actuator located on the first path;
an amplifier located on the first path;
an echo cancellation (EC) actuator located on the second path; and
a data interface comprising a plurality of channels connecting the apparatus to a signal processor, wherein DPD coefficients, EC coefficients and delay parameters are provided over the data interface from the signal processor to the apparatus, wherein the DPD actuator predistorts the first signals on the first path using the DPD coefficients compensating for distortions introduced by the amplifier, wherein the EC actuator reduces interferences in the second signals on the second path using the EC coefficients and the delay parameters, facilitating full duplex (FDX) communication by the apparatus in a cable network, and wherein the signal processor samples the first signals and the second signals traversing the apparatus and computes the DPD coefficients, EC coefficients and delay parameters offline at a predetermined interval.

2. The apparatus of claim 1 , wherein the signal processor comprises a DPD coefficient finder, an EC coefficient finder, and a delay coefficient finder, wherein the DPD coefficient finder computes the DPD coefficients, wherein the EC coefficient finder computes the EC coefficients and the delay coefficient finder computes the delay parameters.

3. The apparatus of claim 1 , wherein the processing comprises predistorting the first signals on the first path by the DPD actuator, and wherein the processing further comprises reducing interferences in the second signals on the second path by the EC actuator.

4. The apparatus of claim 1 , wherein the data interface comprises at least four channels providing data from the apparatus to the signal processor, wherein the at least four channels comprise:
a first channel (D 1 ) providing samples of the first signals into the DPD actuator on the first path,
a second channel (D 2 ) providing samples of the first signals out of the amplifier on the first path,
a third channel (D 3 ) providing a base band (BB) portion of the first signals on the first path, and
a fourth channel (D 4 ) providing a BB portion of the second signals on the second path.

5. The apparatus of claim 4 , wherein the data interface further comprises at least three additional channels providing data from the signal processor to the apparatus, wherein the at least three additional channels comprises:
a fifth channel (C 1 ) providing the a first portion of the DPD coefficients computed using the data provided over the first channel and the second channel,
a sixth channel (C 2 ) providing a second portion of the DPD coefficients computed using the data provided over the first channel and the second channel, and
a seventh channel (C 3 ) providing the EC coefficients and the delay parameters using the data provided over the third channel and the fourth channel.

6. The apparatus of claim 1 , further comprising an ADC located on a third path between an output of the amplifier and the EC actuator.

7. The apparatus of claim 6 , wherein the data interface comprises at least five channels providing data from the apparatus to the signal processor, wherein the at least five channels comprises:
a first channel (D 1 ) providing samples of the first signals into the DPD actuator on the first path,
a second channel (D 2 ) providing samples of the first signals out of the amplifier on the first path,
a third channel (D 3 ) providing a BB portion of the first signals on the first path,
a fourth channel (D 4 ) providing a BB portion of the first signals on the third path, and
a fifth channel (D 5 ) providing a BB portion of the second signals on the second path.

8. The apparatus of claim 7 , wherein the data interface further comprises at least two additional channels providing data from the signal processor to the apparatus, wherein the at least two additional channels comprises:
a sixth channel (D 6 ) providing the DPD coefficients computed using the data provided over the first channel and the second channel, and
a seventh channel (D 7 ) providing the EC coefficients and the delay parameters using the data provided over the third channel, the fourth channel and the fifth channel.

9. The apparatus of claim 1 , further comprising: a combiner connected to the first path on a first port of the combiner, to the second path on a second port of the combiner and to a coaxial cable on a third port of the combiner, the coaxial cable connecting the apparatus to the cable network, wherein the first signals on the first path are transmitted out of the apparatus over the coaxial cable, and wherein the second signals on the second path are received into the apparatus over the coaxial cable.

10. The apparatus of claim 1 , further comprising:
a digital-to-analog converter (DAC) located between the DPD actuator and the amplifier on the first path, wherein the DAC converts the predistorted signals from the DPD actuator from digital domain to analog domain; and
an analog-to-digital converter (ADC) located on the second path, wherein the ADC converts signals to the EC actuator from analog domain to digital domain.

11. A method executed at an integrated circuit in a cable network, the method comprising:
providing samples of signals traversing a first path and a second path in the integrated circuit to a signal processor over a data interface;
receiving DPD coefficients, EC coefficients and delay parameters over the data interface from the signal processor;
predistorting first signals on the first path using the DPD coefficients by a DPD actuator located on the first path, wherein the predistortions compensate for distortions introduced by an amplifier located on the first path; and
reducing interferences on second signals on the second path using the EC coefficients and delay parameters by an EC actuator located on the second path, facilitating FDX communication by the integrated circuit in a cable network, wherein the signal processor samples the first signals and the second signals traversing the integrated circuit and computes the DPD coefficients, EC coefficients and delay parameters offline at a predetermined interval.

12. The method of claim 11 , wherein the data interface comprises at least four channels providing data from the integrated circuit to the signal processor, wherein the at least four channels comprises:
a first channel (D 1 ) providing samples of the first signals into the DPD actuator on the first path,
a second channel (D 2 ) providing samples of the first signals out of the amplifier on the first path,
a third channel (D 3 ) providing a base band (BB) portion of the first signals on the first path, and
a fourth channel (D 4 ) providing a BB portion of the second signals on the second path.

13. The method of claim 12 , wherein the data interface further comprises at least three additional channels providing data from the signal processor to the integrated circuit, wherein the at least three additional channels comprises:
a fifth channel (C 1 ) providing the a first portion of the DPD coefficients computed using the data provided over the first channel and the second channel,
a sixth channel (C 2 ) providing a second portion of the DPD coefficients computed using the data provided over the first channel and the second channel, and
a seventh channel (C 3 ) providing the EC coefficients and the delay parameters using the data provided over the third chann

Assignees

• Cisco Tech Inc

Inventors

• Jin Hang
• Chapman John T

Classifications

• H04L5/14

  Two-way operation using the same type of signal, i.e. duplex · CPC title

• H04B3/23 Primary

  using a replica of transmitted signal in the time domain, e.g. echo cancellers · CPC title

• H04L5/1461

  Suppression of signals in the return path, i.e. bidirectional control circuits · CPC title

• H04B3/232

  using phase shift, phase roll or frequency offset correction · CPC title

• H04L12/2801

  Broadband local area networks · CPC title