Methods for training of full-duplex wireless systems

• US 10,601,569 B2
• Filed: 12/19/2018
• Issued: 03/24/2020
• Est. Priority Date: 02/12/2016
• 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:
  US16/225,064
• Publication Number:
  US 20190123885A1
• Time in Patent Office: 461 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. An apparatus comprising:

a first full-duplex transceiver including;

an antenna configured to exchange radio-frequency signals with a second full-duplex transceiver;

a processor coupled to the antenna, the processor configured to;

measure a self-interference signal;

compare the self-interference signal with a threshold to determine whether a residual self-interference signal exceeds the threshold; and

in response to the determination that the residual self-interference signal exceeds the threshold, direct 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 apparatus of claim 1, wherein the processor is further configured to embed information based on a signal-to-interference plus noise ratio in a distant training signal transmitted to the second full-duplex transceiver.

3. The apparatus of claim 1, wherein the processor is further configured to embed 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 apparatus of claim 1, wherein the processor is further configured to:

direct the self-training operation by transmission of self-training symbols in half-duplex mode; and

send a message to the second full-duplex transceiver to remain silent during the self-training operation.

5. The apparatus of claim 1, wherein the processor is configured to:

transmit a first distant-training symbol of the set of distant-training symbols 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

receive a second distant-training symbol from the second full-duplex transceiver to enable teaching of the first full-duplex transceiver of a channel from the second to the first full-duplex transceiver.

6. The apparatus of claim 5, wherein the processor is configured to transmit the first distant-training signal by time-multiplexing the first distant-training signal in half-duplex mode.

7. The apparatus of claim 5, wherein the processor is configured to transmit the first distant-training signal by time-multiplexing the first distant-training signal in full-duplex mode.

8. The apparatus of claim 5, wherein the processor is configured to transmit the first distant-training symbol by time-multiplexing the first distant-training symbol in a different time slot than a time slot used for receiving the second distant-training symbol.

9. The apparatus of claim 5, wherein the processor is configured to transmit the first distant-training symbol by time-multiplexing the first distant-training symbol in a time slot equal to a time slot used for receiving the second distant-training symbol.

10. The apparatus of claim 8, wherein the processor is configured to use the second distant-training symbol to determine self-interference in the channel from the second full-duplex transceiver to the first full-duplex transceiver.

11. The apparatus of claim 10, wherein the processor is configured to direct the self-training operation based on the determined self-interference in the channel from the second full-duplex transceiver to the first full-duplex transceiver.

12. The apparatus of claim 11, wherein the first transceiver sends a message to the second transceiver to delay performing a distant training operation if performing a self-training operation.

13. The apparatus 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.

14. The apparatus 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.