Echo cancellation for high speed full duplex data transmissions

Patent metadata

Field	Value
Publication number	US-10116428-B2
Application number	US-201415312149-A
Country	US
Kind code	B2
Filing date	May 20, 2014
Priority date	May 20, 2014
Publication date	Oct 30, 2018
Grant date	Oct 30, 2018

Abstract

Systems, devices and methods for analog echo cancellation for high speed full duplex data transmissions, which include a first set of differential nodes to receive reception data and transmission data, a second set of differential nodes to receive the transmission data, and a subtraction circuit to receive data from the first set of differential nodes and data from the second set of differential nodes. The subtraction circuit includes a plurality of capacitors to receive data from each of the first and second sets differential nodes, and a termination circuit for providing DC termination voltage to subtract the data of the second set of differential nodes from the data of the first set of differential nodes to eliminate echo from the reception data received at the first set differential nodes.

First claim

The invention claimed is:

1. An apparatus comprising:
a first set of differential nodes to receive a reception data and a transmission data;
a second set of differential nodes to receive the transmission data; and
a subtraction circuit to receive data from the first set of differential nodes and data from the second set of differential nodes, the subtraction circuit further comprising:
a plurality of capacitors to receive data from each of the first and second sets of differential nodes, wherein inputs of a first pair of the capacitors are coupled to the second set of differential nodes and inputs of a second pair of the capacitors are coupled to the first set of differential nodes; and
a termination circuit for providing DC termination voltage to subtract the data of the second set of differential nodes from the data of the first set of differential nodes to eliminate echo from the reception data received at the first set of differential nodes, wherein an output of a first capacitor from the first pair and an output of a first capacitor from the second pair are coupled to a first node of the termination circuit, and an output of a second capacitor from the first pair and an output of a second capacitor from the second pair are coupled to a second node of the termination circuit.

2. The apparatus of claim 1 , further comprising
first and second drivers to drive the transmission data to the first and second sets of differential nodes, respectively.

3. The apparatus of claim 2 , further comprising:
a filter circuit to equalize the received data from the first set of differential nodes and data from the second set of differential nodes at the subtraction circuit.

4. The apparatus of claim 3 , wherein equalizing the received data from the first set of differential nodes and data from the second set of differential nodes at the subtraction circuit is to compensate for differences between the first and second drivers.

5. The apparatus of claim 3 , wherein the filter circuit is further configured to boost gain and reduce attenuation in signal bandwidth.

6. The apparatus of claim 1 , wherein the termination circuit comprises one or more resistive components to prevent data signal reflection.

7. The apparatus of claim 1 , wherein the transmission and reception data comprises at least one of high definition audio or video data.

8. A method comprising:
receiving a reception data and a transmission data at a first set of differential nodes;
receiving the transmission data at a second set of differential nodes; and
receiving data from the first set of differential nodes and data from the second set of differential nodes at a subtraction circuit, the subtraction circuit including:
a plurality of capacitors for receiving data from each of the first and second sets of differential nodes, wherein inputs of a first pair of the capacitors are coupled to the second set of differential nodes and inputs of a second pair of the capacitors are coupled to the first set of differential nodes; and
a termination circuit for providing DC termination voltage to subtract the data of the second set of differential nodes from the data of the first set of differential nodes to eliminate echo from the reception data received at the first set of differential nodes, wherein an output of a first capacitor from the first pair and an output of a first capacitor from the second pair are coupled to a first node of the termination circuit, and an output of a second capacitor from the first pair and an output of a second capacitor from the second pair are coupled to a second node of the termination circuit.

9. The method of claim 8 , further comprising:
equalizing the received data from the first set of differential nodes and data from the second set of differential nodes at the subtraction circuit.

10. The method of claim 9 , wherein equalizing the received data from the first set of differential nodes and data from the second set of differential nodes at the subtraction circuit is to compensate for cable loss of the reception data.

11. The method of claim 8 , wherein the transmission data received at the first and second set of differential nodes is received from first and second drivers, respectively.

12. The method of claim 8 , wherein the transmission and reception data comprises at least one of high definition audio or video data.

13. A system comprising:
a first device; and
a second device, operatively coupled to the first device to exchange multimedia data, wherein the first and second devices each include:
a first set of differential nodes to receive a reception data and a transmission data;
a second set of differential nodes to receive the transmission data; and
a subtraction circuit to receive data from the first set of differential nodes and data from the second set of differential nodes, the subtraction circuit further comprising:
a plurality of capacitors for receiving data from each of the first and second sets of differential nodes, wherein inputs of a first pair of the capacitors are coupled to the second set of differential nodes and inputs of a second pair of the capacitors are coupled to the first set of differential nodes; and
a termination circuit for providing DC termination voltage to subtract the data of the second set of differential nodes from the data of the first set of differential nodes to eliminate echo from the reception data received at the first set of differential nodes, wherein an output of a first capacitor from the first pair and an output of a first capacitor from the second pair are coupled to a first node of the termination circuit, and an output of a second capacitor from the first pair and an output of a second capacitor from the second pair are coupled to a second node of the termination circuit.

14. The system of claim 13 , wherein the first and second devices further include:
an equalization circuit to equalize the received data from the first set of differential nodes and data from the second set of differential nodes at the subtraction circuit.

15. The system of claim 14 , wherein the first and second devices are communicatively coupled via a cable, and equalizing the received data from the first set of differential nodes and data from the second set of differential nodes at the subtraction circuit is to compensate for cable loss of the reception data.

16. The system of claim 15 , wherein the cable includes at least one of a Mobile High-Definition Link (MHL) connector or a High Definition Multimedia Interface (HDMI) connector.

17. The system of claim 13 , wherein the first and second devices further include:
first and second drivers to drive the transmission data to the first and second sets of differential nodes, respectively.

18. The system of claim 13 , wherein the transmission and reception data comprises at least one of high definition audio or video data.

19. The system of claim 13 , wherein the first device comprises a display panel and the second device comprises a mobile computing device.

Assignees

• Lattice Semiconductor Corp

Inventors

• Wu Qiming
• Lei Kai
• Song Fei
• Zhou Kai
• Ahn Gijung
• Wu Zhi
• Kim Min-Kyu

Classifications

• H04B3/23 Primary

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

• H04B3/30

  Reducing interference caused by unbalanced currents in a normally balanced line · CPC title

• H04L5/1461 Primary

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