Methods for training of full-duplex wireless systems

• US 10,177,896 B2
• Filed: 02/13/2017
• Issued: 01/08/2019
• Est. Priority Date: 05/13/2013
• Status: Active Grant

• Current Assignee: Amir Keyvan Khandani
• Original Assignee: Amir Keyvan Khandani
• Inventors: Khandani, Amir Keyvan
• Primary Examiner(s): Abelson, Ronald B
• Application Number:
  US15/431,764
• Publication Number:
  US 20170237545A1
• Time in Patent Office: 694 Days
• CPC Class Codes: H04B 17/14 of the whole transmission and reception path, e.g. self-test loop-back
• CPC Class Codes: H04B 17/336 Signal-to-interference ratio [SIR] or carrier-to-interference ratio [CIR]
• CPC Class Codes: H04B 17/345 Interference values signal-to-interference ratio [SIR] or carrier-to-interference ratio [CIR] H04B17/336
• CPC Class Codes: H04L 5/14 Two-way operation using the same type of signal, i.e. duplex

Abstract

A method and apparatus for (a) operating a first full-duplex transceiver to exchange radio-frequency signals with a second full-duplex transceiver, (b) determining at the first full-duplex transceiver that a residual self-interference signal exceeds a threshold, (c) in response to the determination that the residual self-interference signal exceeds the threshold, performing a self-training operation.

Claims

1. A method comprising:

exchanging radio-frequency signals at a first full-duplex transceiver with a second full-duplex transceiver;

measuring a self-interference signal at the first full-duplex transceiver;

comparing by the first full-duplex transceiver the self-interference signal with a threshold to determine whether the residual self-interference signal exceeds the threshold;

in response to the determination that the residual self-interference signal exceeds the threshold, performing, by the first full-duplex transceiver, a self-training operation, the self-training operation using self-training signals that are phase-shifted versions of a set of distant-training signals.

2. The method of claim 1, further comprising embedding information based on signal-to-interference plus noise ratio in a distant training signal transmitted by the first full-duplex transceiver to the second full-duplex transceiver.

3. The method of claim 1, further comprising embedding information on an index of a layer to use for self-training, including information related to phase of distant-training symbols sent to a distant counterpart.

4. The method of claim 1, wherein performing the self-training operation comprises transmitting the self-training symbols in half-duplex mode and further comprising sending a message from the first full-duplex transceiver to the second full-duplex transceiver to remain silent during the self-training operation.

5. The method of claim 1, wherein performing the self-training operation comprises transmitting the self-training symbols in full-duplex mode.

6. The method of claim 1, wherein the self-training operation comprises:

transmitting a first distant-training symbol of the set of distant-training symbols from the first full-duplex transceiver to the second full-duplex transceiver to teach the second full-duplex transceiver of a channel from the first to second full-duplex transceiver; and

receiving a second distant-training symbol from the second full-duplex transceiver by the first full-duplex transceiver to teach the first full-duplex transceiver of a channel from the second to the first full-duplex transceiver.

7. The method of claim 6, wherein transmitting the first distant-training signal comprises time-multiplexing the first distant-training signal in half-duplex mode.

8. The method of claim 6, wherein transmitting the first distant-training signal comprises time-multiplexing the first distant-training in full-duplex mode.

9. The method of claim 6, wherein transmitting the first distant-training symbol comprises time-multiplexing the first distant-training symbol in a different time slot than a time slot used for receiving the second distant-training symbol.

10. The method of claim 6, wherein transmitting the first distant-training symbol comprises time-multiplexing the first distant-training symbol in a time slot equal to a time slot used for receiving the second distant-training symbol.

11. The method of claim 6, further comprising using the second distant-training symbol to determine self-interference in the channel from the second full-duplex transceiver to the first full-duplex transceiver.

12. The method of claim 11, further comprising performing a self-training operation based on the determined self-interference in the channel from the second full-duplex transceiver to the first full-duplex transceiver.

13. The method of claim 12, further comprising sending a message from the first transceiver to the second transceiver to delay performing a distant training operation if performing a self-training operation.

14. The method of claim 1, wherein the self-training operation comprises transmitting successively first and second distant-training symbols of the set of distant-training symbols from the first full-duplex transceiver to the second full-duplex transceiver with a time interval for the successive transmission that is adapted to a rate of variations in a channel from the first full-duplex transceiver to the second full-duplex transceiver.

15. The method of claim 1, wherein performing a self-training operation comprises transmitting a partial self-training signal that comprises multiple layers of different depths in a nested manner.