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

Patent metadata

Field	Value
Publication number	US-2019097674-A1
Application number	US-201816130865-A
Country	US
Kind code	A1
Filing date	Sep 13, 2018
Priority date	Sep 27, 2017
Publication date	Mar 28, 2019
Grant date	—

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

1 . A device 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 device comprising at least one first reduction module, configured to take a replica of the transmission signal, and configured to generate a first reduction signal, wherein it further comprises:
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.

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

3 . The device according to claim 1 , said device being configured to apply a digital delay to the replica of the baseband signal before said replica is supplied to the second reduction module.

4 . The device according to claim 1 , said first reduction module being configured to apply 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.

5 . The device according to claim 2 , said second reduction module being configured to apply 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 self-interference contribution included in the reception signal and the first reduction signal, and, on the other hand, the second reduction signal.

6 . A communication device, comprising a plurality of communication nodes (NODE_RF_IBFD_1, NODE_RF_IBFD_2, NODE_RF_IBFD_3, . . . , NODE_RF_IBFD_N), at least one of the communication nodes (NODE_RF_IBFD_1, NODE_RF_IBFD_2, NODE_RF_IBFD_3, . . . , NODE_RF_IBFD_N) being equipped with a device for reducing at least one self-interference contribution according to claim 1 , and a device for reducing interferences generated by the other communication nodes (NODE_RF_IBFD_1, NODE_RF_IBFD_2, NODE_RF_IBFD_3, . . . , NODE_RF_IBFD_N).

7 . 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, wherein it further comprises at least the following steps:
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.

8 . The method according to claim 7 , a temporal derivative of said replica of the baseband signal mixed with the transmission carrier being supplied to the second reduction module.

9 . The method according to claim 7 , a digital delay being applied to said replica of the baseband signal before said replica is supplied to the second reduction module.

10 . The method according to claim 7 , 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.

11 . The method according to claim 8 , 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.

12 . The method according to claim 11 , further comprising a calibration step, said calibration step comprising the following substeps:
a first substep of determination of the first complex gain of the first reduction module, which minimizes the difference between the self-interference contribution included in the reception signal and corresponding to the transmission signal, and the first reduction signal, called residue signal; then a second substep of determination of the second complex gain of the second reduction module which minimizes the difference between the residue signal and the second reduction signal.

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

14 . The method according to claim 12 , said substep of determination of the second complex gain further comprising the determination of the digital delay minimizing the difference between the residue signal and the second reduction signal.

15 . The method according to claim 12 , 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

• H04B3/232

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

• H04B15/00

  Suppression or limitation of noise or interference (by means associated with receiver H04B1/10) · CPC title

• H04L5/1461

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

• H04B1/0475

  with means for limiting noise, interference or distortion (H04B1/0483 takes precedence) · CPC title

• H04B3/23

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