Device and method for reducing the self interference signal in a full-duplex communication system

Patent metadata

Field	Value
Publication number	US-10917133-B2
Application number	US-201816130865-A
Country	US
Kind code	B2
Filing date	Sep 13, 2018
Priority date	Sep 27, 2017
Publication date	Feb 9, 2021
Grant date	Feb 9, 2021

Abstract

A device for reducing a self-interference contribution in a full-duplex wireless communication system configured to transmit a transmission signal and modulated by a baseband signal, and configured to receive a reception signal containing a self-interference contribution corresponding to the transmission signal, the reduction device comprising a first reduction module, configured to take a replica of the transmission signal, and configured to generate a first reduction signal, the device further comprising: a second reduction module, arranged so as to be able to take a replica of the baseband signal, and capable of generating a second reduction signal that is a function of the temporal derivative of the baseband signal, a subtractor, linked to the first reduction module and to the second reduction module, and configured to subtract from the reception signal the first reduction signal and the second reduction signal.

First claim

The invention claimed is:

1. A method for reducing at least one self-interference contribution in a full-duplex wireless communication system, configured to transmit a transmission signal with a transmission carrier and modulated by a baseband signal, and configured to receive a reception signal containing at least one self-interference contribution corresponding to the transmission signal, said reduction method comprising:
at least one first reduction step, in which a first reduction module takes a replica of the transmission signal and generates a first reduction signal,
a second reduction step, in which a second reduction module generates a second reduction signal that is a function of the temporal derivative of the replica of the baseband signal,
a subtraction step in which the first reduction signal and the second reduction signal are subtracted from the reception signal, and
a calibration step prior to said first and second reduction steps and prior to said subtraction step, said calibration step comprising the following substeps:
a first substep of determination of a first complex gain of the first reduction module, which minimizes a residue signal corresponding to the difference between the self-interference contribution included in the reception signal and corresponding to the transmission signal, and the first reduction signal; then
a second substep of determination of a second complex gain of the second reduction module which minimizes the difference between the residue signal and the second reduction signal,

wherein the calibration step further comprises a substep of determination of a digital delay minimizing the difference between the residue signal and the second reduction signal, said substep of determination of a digital delay being performed after the first substep of determination of a first complex gain and after the second substep of determination of a second complex gain.

2. The method according to claim 1 , a temporal derivative of said replica of the baseband signal mixed with the transmission carrier being supplied to the second reduction module.

3. The method according to claim 2 , said second reduction module applying a second complex gain to the temporal derivative of the replica of the baseband signal mixed with the transmission carrier, the second complex gain being determined so as to generate a destructive interference between, on the one hand, a residue of the destructive interference between the at least one self-interference contribution included in the reception signal and the first reduction signal, and, on the other hand, the second reduction signal.

4. The method according to claim 1 , a digital delay being applied to said replica of the baseband signal before said replica is supplied to the second reduction module.

5. The method according to claim 1 , said first reduction module applying a first complex gain to a replica of the transmission signal in order to supply the first reduction signal, the first complex gain being determined so as to generate a destructive interference between the self-interference contribution included in the reception signal and the first reduction signal.

6. The method according to claim 1 , said substep of determination of the second complex gain further comprising the determination of a digital delay minimizing the difference between the residue signal and the second reduction signal.

7. The method according to claim 1 , said calibration step being performed periodically or in case of a change of the environment of the full-duplex wireless communication system.

Assignees

• Commissariat Energie Atomique

Inventors

• Grave Baptiste
• Giry Alexandre

Classifications

• H04B1/123 Primary

  using adaptive balancing or compensation means (adaptive filter circuits and algorithms H03H) · CPC title

• H04B3/232

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

• H04L5/1461

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

• H04B3/23

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

• H04B15/04

  the interference being caused by substantially sinusoidal oscillations, e.g. in a receiver or in a tape-recorder · CPC title