Full-duplex communication method and associated wireless communication device

Abstract

Full-duplex communication method and associated wireless communication device. The invention relates to a full-duplex communication method implemented by a wireless communication device comprising a set of transmitting antenna elements, a set of receiving antenna elements, and a plurality of RF chains, each RF chain being connected to at least one of said receiving antenna elements. The method comprises: reception, by at least one receiving antenna element of the wireless communication device, of first signals emitted by at least one wireless transmitting device and at least one user terminal, and of a second signal emitted by at least one transmitting antenna element of the wireless communication device to at least one wireless receiving device, and processing of the first and second received signals, at least one of said RF chains being dedicated to processing the second signal.Figure for the abridged version: Fig. 1.

Description

Title of the invention: Full-duplex communication method and associated wireless communication device Technical field

[0001] The present invention belongs to the general field of telecommunications, and in particular wireless communications implemented on radio-type networks such as mobile networks (e.g. 3G, 4G, 5G, B5G etc.), Wi-Fi, etc. It relates more particularly to a full-duplex communication method. It also relates to a wireless communication device comprising an array of antenna elements, said device having an architecture configured to transmit and receive signals in the form of beams via said antenna elements.

[0002] The invention finds a particularly advantageous, although in no way limiting, application in the case of a wireless communication device of the MIMO type (acronym for the English expression "Multiple Input Multiple Output") using several antennas for transmission and reception, and in particular in the case of a wireless communication device of the massive MIMO type relying on a large number of antennas (typically from 16 to 128 antennas, this number being likely to increase in the future). Prior art

[0003] In order to adapt to the continuous and ever-increasing growth of data traffic emitted by wireless communications systems, different technologies are currently being implemented and are still being improved with a view to optimal exploitation in the years to come.

[0004] Among these technologies, and more particularly in the context of MIMO type wireless communications systems, it is known to configure a wireless communications device, such as for example a base station or a mobile telephone, with the aim of simultaneously transmitting and receiving several data streams via an antenna network (i.e. a set of antenna elements or elementary antennas) equipping said wireless communications device. This is referred to as "full-duplex" type communication when data are transmitted and received simultaneously, and more specifically as "in band full-duplex" type communication when data are transmitted and received simultaneously using the same frequency band. Advantageously, these data streams are carried by directional transmission beams (also called "beamforming" in the English literature) formed for this purpose.The use of such beams thus allows the wireless communication device to deliver or receive data with a . high spectral efficiency as well as high throughput.

[0005] "Full-duplex" type communications are notably implemented within the framework of "Integrated Access and Backhaul" (IAB) architectures, which offer a connection between a user terminal (UE) and a base station ("IAB-donor") connected to the core network via an intermediate base station ("IAB-node") acting as a relay between the user terminal and the base station connected to the core network.

[0006] However, the main challenge of "full-duplex" communications is self-interference, which is caused by the coupling of the transmitting antenna elements with the receiving antenna elements. Indeed, since the reception and transmission of signals are implemented simultaneously (and this, using the same frequency band), a signal for example transmitted by a first base station to a second base station will inevitably be received by the receiving antenna elements of the first base station, while this first base station would only wish to receive signals from other devices. This signal received when it was not desired is generally called "self-interference signal" (SI).

[0007] This is all the more true in the context of the 5G standard (fifth generation of the mobile telephony standard) where the attenuation in free space is significant, and where the signal of interest (eg, coming from another device) is of much lower amplitude than the amplitude of the self-interference signal.

[0008] Various interference cancellation methods have been developed. Some aim to improve the isolation between the receiving antenna elements and the transmitting antenna elements in a topological manner. Others operate at the analog (RF or baseband) or digital level by copying a portion of the transmitted signal and then subtracting it on the receiving path in order to eliminate the self-interference signal.

[0009] However, these methods cancel the self-interference signal by passing into the analog and / or time domain. However, cancellation in the analog domain can suffer from constraints and imperfections related to the analog components, and cancellation in the time domain suffers from a high sensitivity to synchronization. Indeed, the slightest difference between the two signals can induce significant errors. Statement of the invention

[0010] The present invention aims to remedy all or part of the drawbacks of the prior art, in particular those set out above, by proposing a solution which makes it possible to cancel a self-interference signal by exploiting the spatial domain offered by the sets of receiving and transmitting antenna elements of a wireless communication device, while remaining in the so-called modulation domain (i.e., frequency, time or other).

[0011] To this end, and according to a first aspect, the invention relates to a full-duplex communication method implemented by a wireless communication device comprising a set of transmitting antenna elements, a set of receiving antenna elements and a plurality of RF chains, each RF chain being connected to at least one of said receiving antenna elements, the method comprising: • reception, by at least one receiving antenna element of the wireless communication device, of first signals transmitted by at least one wireless transmitting device and at least one user terminal, and of a second signal - called self-interference signal - transmitted by at least one transmitting antenna element of the wireless communication device and intended for at least one wireless receiving device, and • processing of the first and second received signals aimed at reducing a power level received by the receiving antenna elements following reception of the second signal, at least one of said RF chains being dedicated to processing the second signal.

[0012] These communications are implemented simultaneously. The advantages of full-duplex in-band communication lie in particular in the fact that the wireless communication device according to the invention is capable of simultaneously transmitting and receiving signals in a frequency band associated with it. Such arrangements advantageously make it possible to avoid having to use multiple frequency bands, which are rare resources, to transmit and receive signals on the one hand, thus improving the spectral efficiency of said device.

[0013] Generally speaking, those skilled in the art may refer to the following document for further details regarding the implementation of full-duplex communications: "In-Band Full-Duplex Wireless: Challenges and Opportunities", A. Sabharwal, P. Schniter, D. Guo, DW Bliss, S. Rangarajan, R. Wichman, IEEE Journal of Selected Areas in Communications, vol. 32, no. 9, pp. 1637-1652, Sept. 2014.

[0014] The first and second signals are received by the wireless communication device in the form of directional transmission beams.

[0015] It is also important to note that the communication method according to the first aspect of the invention is "downlink", since the first signal is transmitted to at least one user terminal.

[0016] Generally speaking, it is considered that the steps of a method should not be interpreted as being linked to a notion of temporal succession.

[0017]

[0018]

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[0020]

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[0024]

[0025] In particular embodiments, the communication method may further comprise one or more of the following characteristics, taken individually or in all technically possible combinations. In particular embodiments, the processing comprises an analog post-coding step by applying an analog post-coding WRF matrix constructed by horizontal concatenation of pointing column vectors originating from the set of transmitting antenna elements, the at least one wireless transmitting device, and the at least one user terminal, and pointing towards the set of receiving antenna elements. In particular embodiments, the analog post-coding matrix is ​​of dimension x (K + K + K\ with a number of transmitting antenna elements of the wireless communication device, K a number of wireless receiving devices such that K > 1, g a number of wireless transmitting devices such that K > 1 and K a number of user terminals such that K >1. In particular embodiments, the analog post-coding matrix is ​​of the form eSIC(k=O) 0 ...... 0 0 : eSIC(k=KA) 0 ... ; 0 eBH ( l(W'=o) 0 : : 0 ) 0 - : ; ; ■ o ^UE(k=0) 0 : ■ o ; < 0 ......eUE(k=K-])t with eSIC\k=0.Kl) the pointing vectors of the set of transmitting antenna elements, eBH(ïo^k=oK-i) the pointing vectors of the K wireless transmitting devices, and eUE(k =o.. k ) the pointing vectors of the K user terminals. In particular embodiments, the processing further comprises a digital post-coding step by applying a digital post-coding matrix bb, said WBB matrix being determined by applying a zero forcing criterion. In particular implementations, the digital post-coding WBB matrix is ​​defined as: BBZF~ [jlA^ZFHe^HeqHj ,

[0026] with H a matrix representative of a global communication channel, Heq a ​​matrix representative of an equivalent communication channel, H a normalization factor and Azf an objective matrix of dimension (Kr K) X (K + K + K), said matrix AZF resulting from a concatenation of K zero column vector(s) of dimension [K + KJXI, ct of a matrix of dimension qx + K the coefficients of the diagonal of said matrix being greater than the other coefficients of said matrix.

[0027] In particular embodiments, the AZF matrix is ​​a diagonal matrix.

[0028] In particular embodiments, the wireless communication device, the at least one wireless receiving device and the at least one wireless transmitting device are base stations.

[0029] According to a second aspect, the invention relates to a computer program comprising instructions for implementing a communication method according to this first aspect of the invention, when said program is executed by a processor.

[0030] According to a third aspect, the invention relates to a computer-readable information or recording medium on which the computer program according to this first aspect of the invention is recorded.

[0031] The information or recording medium may be any entity or device capable of storing the program. For example, the medium may comprise a storage means, such as a ROM, for example a CD ROM or a microelectronic circuit ROM, or a magnetic recording means, for example a floppy disk or a hard disk.

[0032] On the other hand, the information or recording medium may be a transmissible medium such as an electrical or optical signal, which may be conveyed via an electrical or optical cable, by radio or by other means. The program according to the invention may in particular be downloaded from a network such as the Internet.

[0033] Alternatively, the information or recording medium may be an integrated circuit in which the program is incorporated, the circuit being adapted to execute or to be used in the execution of the method in question.

[0034] According to a fourth aspect, the invention relates to a wireless communication device configured to communicate in full-duplex, and comprising: • a set of transmitting antenna elements; • a set of receiving antenna elements; • a plurality of RF chains, each RF chain being connected to at least one of said receiving antenna elements; • a module for receiving first signals emitted by at least one wireless transmission device and at least one user terminal, and a second signal - called self-interference signal - emitted by at least one transmission antenna element of the wireless communication device and intended for at least one wireless reception device, and • a module for processing the first and second received signals configured to reduce a power level received by the receiving antenna elements following reception of the second signal, at least one of said RF chains being dedicated to processing the second signal.

[0035] The invention is particularly advantageous insofar as the communication device according to the invention can take the form of equipment already present in the environment of a communication network. For example, it can be a base station, etc.

[0036] According to a fifth aspect, the invention relates to a method for full-duplex communication in a system including a wireless communication device, at least one wireless receiving device, at least one user terminal and at least one wireless transmitting device, the wireless communication device comprising a set of receiving antenna elements and a set of transmitting antenna elements, the method being implemented by the wireless communication device and comprising: • hybrid beamforming including baseband precoding by applying an analog precoding FBB matrix; and, • a transmission, by the set of transmission antenna elements and in the form of beams, of a signal intended for at least one wireless reception device and of a signal intended for at least one user terminal, the transmission causing the reception, by the set of reception antenna elements of self-interference signals, said FBB matrix being determined so as to minimize a cost function between a plurality of signals transmitted and a plurality of signals received in said system, and by applying the following constraints: • the signals are transmitted in accordance with a transmission power less than or equal to an available power; • the first row of a resulting matrix Heq F is a vector of which at least one of the coefficients is less than a threshold value, with Heq a ​​matrix representative of an equivalent communication channel, and M the conjugate of the matrix M,

[0037] In particular embodiments, the cost function corresponds to the mean square error, and the precoding FBB matrix is ​​defined such that: FBB.MMSEC= eq + 2qZ )

[0039] with H a matrix representative of a global communication channel, Heq a ​​matrix representative of an equivalent communication channel, a Lagrange factor, and AMMSEC an objective matrix of dimension + K + K + 1) X (K + K + K y with a number of wireless receiving devices (20) such that K > 1, g' a number of wireless transmitting devices (40) such that K > 1 and K a number of user terminals (30) such that K > L said matrix A-mmsec corresponding to the vertical concatenation of a diagonal matrix of dimension 4. X + KX (K + K + K y and a row vector of dimension 1 X (Â" + K + K] each coefficient of which represents a cancellation constraint of a self-interference signal.

[0040] In particular embodiments, the first row of the resulting matrix Heq FBB is a zero vector, and the first row of the matrix AMMSEC is a zero vector, so as to completely cancel the effect of the self-interference signals.

[0041] In particular embodiments, the method further comprises a determination of said analog precoding FBB matrix by said wireless communication device.

[0042] In particular embodiments, the method further comprises a step of determining an analog precoding FRF matrix by concatenation of K + K pointing column vectors which point towards the at least one wireless reception device and towards the at least one user terminal, one of said vectors being representative of a phase to be applied to a signal at the input of at least one of said transmission antenna elements.

[0043] In particular embodiments, the method further comprises a step of determining an equivalent RF coupler WRFœq of analog post-coding by concatenation of pointing column vectors between the K wireless transmission devices and the set of reception antenna elements, between the set of transmission antenna elements and the K wireless reception devices, and between the set of transmission antenna elements and the K user terminals.

[0044] In particular embodiments, the self-interference signals are represented by a spherical wave model.

[0045] In particular embodiments, the communication channel between the same receiving antenna element and the nth transmitting antenna element is modeled such that:

[0046] hn - C

[0047] with pg-H' a complex gain representative of a communication channel between a center O[v of the set of transmitting antenna elements and a center Ors of the set of receiving antenna elements, -AI- an amplitude fluctuation with D a distance between the center Orx and the center 0yv, DmjJ a distance between the mth antenna element of the set of receiving antenna elements and the nth antenna element of the set of transmitting antenna elements, X the wavelength, and Aswm — Dmjl - D a phase shift between the centers Op. and Orx such that:

[0048] A SWMjn n = || - + From t + R aR^ || 2 - D,

[0049] with - a vector between the nth transmitting antenna element and the center Or. , Dir the vector , R a rotation matrix associating a reference frame linked to the set of transmitting antenna elements to a reference frame linked to the set of receiving antenna elements, and aR^ a vector going from the center Ork towards the same antenna element of the set of receiving antenna elements.

[0050] In particular embodiments, the wireless communication device and the at least one wireless receiving device are base stations, and the signal between the wireless communication device and the at least one wireless receiving device is modeled by a plane wave model using a direct line-of-sight communication channel.

[0051] In particular embodiments, the wireless communication device is a base station, and the signal between said wireless communication device and the at least one user terminal is modeled by a plane wave model using a non-line-of-sight communication channel.

[0052] In particular embodiments, the method further comprises a step of modeling a global communication channel including: • a first communication channel - called self-interference - between the set of transmitting antenna elements and the set of elements receiving antenna of said wireless communication device, a second communication channel between the set of transmitting antenna elements and the K wireless receiving devices, and a third communication channel between the set of transmitting antenna elements and the K user terminals, said global communication channel being represented by a matrix H comprising: a first sub-matrix of dimension / LfQ O) x / a æ(ï0) 1 1 Mrxbh ^T^UEs) representative of the first communication channel, with 3rd number Ra. dH receiving antenna elements of the wireless communication device dedicated to receiving signals from the K transmitting devices wireless, the number of transmitting antenna elements of the device wireless communication dedicated to transmitting signals to the K wireless receiving devices and the number of transmitting antenna elements 1 -A. L, o of the wireless communication device dedicated to transmitting signals to the K user terminals, a second sub-matrix of dimension »^(20^) x BH ( -u I representative of the second communication channel- [tvlTX, BH + TX, U Es J 1 nication, with the number of receiving antenna elements of a ^RX.BH 1 wireless receiving device k dedicated to receiving signals, and, a third sub-matrix of dimension y K Jw ) x Lik-=0^Rx ( Mrx BH + M^X, UEs ) representative of the third channel of communication nication, with . JÏW ) the number of antenna element(s) of a uti-mrx terminal dedicated to signal reception.

[0053] According to a sixth aspect, the invention relates to a computer program comprising instructions for implementing a communication method according to this fifth aspect of the invention, when said program is executed by a processor.

[0054] According to a seventh aspect, the invention relates to a computer-readable information or recording medium on which the computer program according to this sixth aspect of the invention is recorded.

[0055] The information or recording medium may be any entity or device capable of storing the program. For example, the medium may comprise a storage means, such as a ROM, for example a CD ROM or a microelectronic circuit ROM, or a magnetic recording means, for example a floppy disk or a hard disk.

[0056] On the other hand, the information or recording medium may be a transmissible medium such as an electrical or optical signal, which may be conveyed via an electrical or optical cable, by radio or by other means. The program according to the invention may in particular be downloaded from a network such as the Internet.

[0057] Alternatively, the information or recording medium may be an integrated circuit in which the program is incorporated, the circuit being adapted to execute or to be used in the execution of the method in question.

[0058] According to an eighth aspect, the invention relates to a wireless communication device configured to communicate in full-duplex in a system including a device

[0059]

[0060]

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[0063]

[0064] wireless communication device, at least one wireless receiving device, at least one user terminal and at least one wireless transmitting device, the wireless communication device comprising: • a set of receiving antenna elements; • a set of transmitting antenna elements; • a hybrid beamforming module including a baseband precoding sub-module by applying an analog precoding FBB matrix; and, • a transmission module, of a signal intended for said at least one wireless reception device and of a signal intended for said at least one user terminal, the transmission causing the reception, by the set of reception antenna elements of self-interference signals, the FBB matrix being determined so as to minimize the mean square error between a plurality of transmitted signals and a plurality of received signals in said system, and by applying the following constraints: • the signals are transmitted in accordance with a transmission power less than or equal to an available power; • the first line of a resulting matrix Hec / F is a vector of which at least one of the coefficients is less than a threshold value, with Heq a ​​matrix representative of an equivalent communication channel, and M the conjugate of the matrix M. Brief description of the drawings Other characteristics and advantages of the present invention will emerge from the description given below, with reference to the appended drawings which illustrate an exemplary embodiment thereof without any limiting character. In the figures: [Fig.l] [Fig.l] is an example of a communication system in which an uplink communication method is implemented; [Fig.2] [Fig.2] is a detailed view of [Fig.l] including the communication channels considered in connection with a wireless communication device (10); [Fig.3] [Fig.3] represents an exemplary implementation of a wireless communication device (10) implementing uplink communication; [Fig.4] [Fig.4] represents an example of distribution of the sets of receiving and transmitting antenna elements of a wireless communication device (10) comprising five RF receiving chains; [Fig.5] [Fig.5] schematically represents modules embedded in a wireless communication device (10), according to an exemplary implementation of the invention;

[0065] [Fig.6] [Fig.6] represents an example of hardware architecture of a wireless communication device (10);

[0066] [Fig.7] [Fig.7] illustrates, in the form of a flowchart, the main stages of a uplink communication method, according to an exemplary implementation of the invention;

[0067] [Fig.8] [Fig.8] is an example of a communication system in which a downlink communication method is implemented;

[0068] [Fig.9] [Fig.9] is a detailed view of [Fig.8] in which the communication channels communication considered in connection with a wireless communication device (10) are considered;

[0069] [Fig. 10] [Fig. 10] represents an exemplary implementation of a wireless communication device (10) implementing a downlink communication method;

[0070] [Fig. 11] [Fig. 11] schematically represents modules embedded in a wireless communication device (10), according to an exemplary implementation of the invention;

[0071] [Fig.12] [Fig.12] represents an example of hardware architecture of a wireless communication device (10);

[0072] [Fig. 13] [Fig. 13] illustrates, in the form of a flowchart, the main steps of a downlink communication method, according to an exemplary implementation of the invention. Description of the embodiments

[0073] Uplink communication

[0074] [Fig.l] is an example of a communication system in which a full-duplex and uplink communication method is implemented, in accordance with the first aspect of the invention.

[0075] The wireless communications system is a multi-antenna or MIMO system. This system comprises a wireless transmission device 40, a wireless communication device 10 according to the invention, a wireless reception device 20, as well as a plurality of user terminals 30. A user terminal 30 corresponds for example to a laptop, a personal assistant, a connected object, a mobile telephone of the “smartphone” type.

[0076] In the present embodiment, and for the purpose of simplifying the description, it is considered that the communication system comprises only said devices 10, 20 and 40, as well as three user terminals 30.

[0077] It should be noted, however, that no limitation is attached to the number of communication devices 10, to the number of wireless receiving devices 20, to the number of wireless transmission devices 40 or the number of user terminals 30. The following developments can in fact be generalized without difficulty by those skilled in the art in the case where more than six devices are considered.

[0078] The wireless communication device 10 comprises a plurality of antenna elements organized in the form of an array of antenna elements and configured to transmit and receive beams, the latter serving as a support for the simultaneous transmission of several data streams to serve one or more determined portions of the space. It should be noted that the number of antenna elements equipping the wireless communication device 10 does not constitute a limiting factor of the invention, provided that this number is greater than 2.

[0079] Each wireless transmission device 40 and wireless reception device 20 is equipped with at least one antenna (eg, at least one antenna element). No limitation is attached to the number of antennas equipping each of said devices 40 and 20.

[0080] In the present embodiment, and for the purpose of simplifying the description, it is considered that each user terminal 30 is equipped with only one antenna, and that they do not communicate in full-duplex. It should however be noted that no limitation is attached to the number of antenna elements of the user terminals.

[0081] Thus, the communication device 10 is able to receive a signal from a user terminal 30, to receive a signal from the wireless transmission device 40, and to transmit a signal to the wireless reception device 20, and this simultaneously ("full-duplex"). The devices 20 and 40 are also configured to communicate in full-duplex.

[0082] Of course, nothing excludes the possibility that the devices 20 and 40 could communicate directly with each other.

[0083] In the present embodiment, and for the purpose of simplifying the description, it is also considered that the communications between the devices 40, 10 and 20 are implemented in one direction only. However, the problem being symmetrical, the following developments can be generalized without difficulty by those skilled in the art to the case where bidirectional communications are implemented between the devices 40, 10 and 20.

[0084] The devices 10, 20, 30 and 40 belong to a wireless communications network (not shown in [Fig.l]) and are capable of communicating with each other in a frequency band associated with this wireless communications network. For the remainder of the description, it is considered in a non-limiting manner that said telecommunications network is a 5G type mobile network.

[0085] It should however be specified that the invention remains applicable to other types of telecommunications network, such as for example a GSM mobile network, 3G (the third generation of mobile telephone network standards), 4G (the fourth generation of mobile telephone network standards), 5G (the fifth generation of mobile telephone network standards) and / or B5G (acronym for "Beyond 5G"). The invention also remains applicable to a Wi-Fi network (acronym for "Wireless Fidelity"), a WiMAX network (acronym for "Worldwide Interoperability for Microwave Access"), a satellite Internet access network, etc. Generally speaking, no limitation is attached to the nature of the telecommunications network that can be considered within the scope of the present invention. Furthermore, the invention is applicable independently of the nature of the data transiting on this network.

[0086] As illustrated by [Fig.l], the wireless transmission device 40 is a base station, for example of the "1AB-donor" type connected to the core network, the wireless communication device 10 is an intermediate base station, and the wireless reception device 20 is also an intermediate base station.

[0087] A base station is sometimes called a "nodeB" in 3G networks, "eNodeB" according to the LTE standard (acronym for "Long Term Evolution") and "gNodeB" in 5G networks.

[0088] According to a particular implementation, the devices 10, 20 and 40 comply with the ETSI TS 123 501 standard (the current version being 17.9.0, published in July 2023 and also referenced "3GPP TS 23.501 version 17.9.0 Release 17").

[0089] It should however be noted that the invention is applicable independently of the nature of said devices 10, 20 and 40, provided that the latter are capable of carrying out wireless communications.

[0090] Thus, as mentioned previously, nothing excludes considering that the devices 10, 20 and / or 40 are access points (AP) of a local area network (Local Area Network), such as a wireless local area network, e.g., conforming to the IEEE 802.11 standards.

[0091] [Fig.2] is a detailed view of [Fig.l] including the communication channels considered in connection with the wireless communication device 10, in accordance with the first aspect of the invention.

[0092] As previously mentioned with reference to [Fig.l], the communication device 10 is configured to be able to simultaneously receive a signal from the wireless transmission device 40, receive other signals from three user terminals 30, and transmit a signal to the wireless reception device 20.

[0093] For these reasons, the wireless transmission device 40 is represented in the form of its network of transmission antenna elements referenced 40(Tx), the wireless reception device 20 is represented in the form of its network of antenna elements reception referenced 20(Rx), and the communication device 10 is represented in the form of its transmit antenna element array 10(Tx) and its receive antenna element array 10(Rx). In order to make the model as generic as possible, in this example, it is considered that there is a tilt angle between the arrays 10(Tx) and 10(Rx), so that the array 10(Rx) is in direct line of sight of the array 10(Tx).

[0094] As illustrated in [Fig.2], the following communication channels are considered: • a HSf communication channel going from the network of transmitting antenna elements 10(Tx) of the communication device 10 to the network of receiving antenna elements 10(Rx) of this same communication device 10, this channel allowing the transmission of a so-called self-interference signal resulting from the transmission, by the network of transmitting antenna elements 10(Tx), of a signal intended for the wireless receiving device 20; • a backhaul H^4o-*1o communication channel going from the network of transmitting antenna elements 40(Tx) to the network of receiving antenna elements 10(Rx) of the communication device 10; • a backhaul Hbhiq-,2q communication channel going from the network of transmitting antenna elements 10(Tx) to the network of receiving antenna elements 20(Rx) of the wireless receiving device 20; • a communication channel ue, from the user terminals 30 to the network of receiving antenna elements 10 (Rx).

[0095] HSI communication channel

[0096] According to a particular implementation, the HS1 communication channel is represented by a spherical wave model. The HSI communication channel between the same receiving antenna element of the set 10(Rx) and the nkme transmitting antenna element of the set 10(Tx) is then modeled such that:

[0097] — pe^^e'^AswMw

[0098] with pe-^ a complex gain representative of a communication channel between a center Or of the set of transmitting antenna elements and a center Opy of the set of receiving antenna elements, -AL. an amplitude fluctuation with D a distance between the center Or and the center Oys, Dm,n a distance between the antenna element of the set of receiving antenna elements 10(Rx) and the nth antenna element of the set of transmitting antenna elements 10(Tx), At the wavelength, and ASWM ~ Dm?n - D a phase shift between the centers Oj- and Or such that:

[0099] ASWMwl = || " '^T^i + Dt^ + R Sr^ || 2 - D,

[0100] with - a vector between the nth transmitting antenna element of the set 10(Tx) and the center Opx, DuJ the vector, R a rotation matrix associating a reference frame linked to the set of transmitting antenna elements 10(Tx) with a reference frame linked to the set of receiving antenna elements 10(Rx), and a vector going from the center Orx towards the nth antenna element of the set of receiving antenna elements 10(Rx).

[0101] Backhaul communication channels

[0102] According to a particular implementation, the backhaul communications channels Hbh40-*w and -^8 / 710*20 are modeled as direct line-of-sight communications channels, and the signals transiting these channels are modeled by a plane wave model.

[0103] This modeling proves to be particularly suitable when the wireless communication device 10, the wireless transmission device 40 and the wireless reception device are base stations at the top of which the antenna assemblies 40(Tx), 10(Rx), 10(Tx) and 20(Rx) are installed, since few obstacles are present at this altitude.

[0104] A communication channel is typically represented by a matrix H, and for the sake of simplification, the channel and its matrix are identified by the same reference. The construction of the matrices representing the backhaul channels is implemented using a ray tracing-based method, so that only the pointing vectors corresponding to the set of transmitting antenna elements and the pointing vectors corresponding to the set of receiving antenna elements are required. The matrices of the backhaul channels are then defined as: [01051 OCl.CO" “ fi (^BH' ) with ^10 = M^h^bh^ 4^ ) and / i, ' 10-*20 1 \ 4d IAM() I

[0106] with and ^10_»20 'cs free space attenuation factors for the channels ^s / / 4O-*io and respectively, <^40—10 (respectively ^m-»20 ) the distance between the devices 40 and 10 (respectively 10 and 20), of dimension x 1 the pointing vector of the set 40(Tx) of transmitting antenna elements of the wireless transmitting device 40, gO® of dimension xl cl of dimension M^bh x 1 'CS pointing vectors of the sets 10(Tx) and 10(Rx) of the communication device 10, of dimension M^b^bh x 1 'c pointing vector of the set 20(Rx) of the wireless receiving device 20 and ¢0°) the azimuth and the elevation angle of the Directions of Departure (DoD) of the set of transmitting elements 10(Tx) of the communication device 10, and the azimuth and the elevation angle Directions of Departure (DoD) of the set of transmitting elements 40(Tx) of the wireless transmitting device 40, M^^bh 'C number of transmitting antenna elements of the device D, and the number of receiving antenna elements of the device D.

[0107] It is important to note that the expressions of and ^10_*90 above consider the particular case where the sets of antenna elements are uniform planar antenna networks ("Uniform Planar Array" according to English terminology), and where the antenna elements are regularly spaced by half a wavelength.

[0108] Furthermore, since the backhaul channels are modeled as direct line-of-sight communication channels, the DoD departure directions of the set of transmitting elements of the communication device 10 (respectively 40) are identical to the angles of arrival ("Direction of Arrivai" according to the English terminology) of the set of receiving antenna elements 20(Rx) (respectively 10(Rx)). From this construction, the dimension of the channel matrix Hbh4^10 is , v and the dimension of the channel matrix is M^bh X iri-KxJ)n

[0109] HUEt UL communication channel

[0110] In practice, the signals transmitted between a user terminal and a communication device such as a base station are frequently reflected by reflectors before reaching their target. For this, the HUE UL communication channel is modeled as a communication channel without direct line of sight. Furthermore, since the user terminals are typically at a certain distance (e.g., from a few tens of meters to around thirty kilometers) from the base station to which they are attached, the signals passing through these channels are modeled by a plane wave model.

[0111] Construction of the HUE VL matrix representative of the channel between the terminals users and the wireless communication device 10 is implemented using a ray tracing based method. More specifically, for each user terminal, a direct beam emitted by the given user terminal 30 towards the communication device 10 is defined, then L - 1 other beams are constructed whose DoD Departure Direction is separated by an angle of and _ in both elevation and azimuth from the main beam.

[0112] To model the environment of the user terminals, it then follows that L beams are emitted from each user terminal 30, and the angle of arrival DoA of these L beams at the level of the receiving antenna elements 10(Rx) is between [-tf; tf] for the elevation and |\ il] for the azimuth.

[0113] As mentioned previously with reference to [Fig.l] and [Fig.2], for the purpose of simplifying the description, it is considered that each user terminal 30 is equipped with only one antenna (eg, isotopic). Also, the number of transmitting antenna elements to be considered corresponds to the number ) of user terminals connected to the wireless communication device 10, and the channel matrix is ​​then constructed by concatenation of column vectors, each column vector representing a transmission by one of the K user terminals. The uith column of the channel matrix Hue, ul is defined as follows: [°n4]

[0115] with L the number of paths induced by the presence of reflectors, ai the complex attenuation coefficient for the 11th path, ri the delay associated with the / 1th path, eR»u the pointing vector of the set 10(Tx) of receiving antenna elements of the communication device 10 of dimension MKxUEu x 1 associated with the wth user terminal, 0u and the azimuth and elevation angles of the ul^me user terminal seen from the wireless communication device 10. The dimension of the channel matrix is ​​then x K , with Mn°L 'c number of receiving antenna elements of the 1\ ç, L* 12s L* communication device 10 dedicated to receiving data from user terminals 30.

[0116] Global Channel Matrix

[0117] The global channel matrix H is then formed by a vertical concatenation of three sub-matrices: • a first sub-matrix gj j r of dimension jyU0) x lio-*k rePæsenta^ve of the communication channel between the set of transmitting antenna elements and the set of receiving antenna elements of said wireless communication device 10, with 21^0°) the number of receiving antenna elements of said wireless communication device 10 and , the number of antenna elements Ta, ItHx transmitting devices of the wireless communication device 10 dedicated to transmitting a signal to the kth wireless receiving device 20; a second dimensional submatrix represented representative of the channels between the set of transmitting antenna elements 40(Tx) of each of the K wireless transmitting devices 40 dedicated to transmitting a signal to the wireless communication device 10, and between the set of receiving antenna elements of the wireless receiving device 20, with ^k) the number of antenna elements transmission 40(Tx) of the kth wireless transmission device 40 dedicated to transmitting a signal to the wireless communication device 10; • a third sub-matrix of dimension 0) x representative of the communication channels between the set of reception antenna elements of said wireless communication device 10 and the total number K of reception antennas of the user terminals 30.

[0118] In other words, the first sub-matrix concerns the reception of a self-interference (SI) signal from the set of transmit antenna elements 10(Tx) of the wireless communication device 10; the second sub-matrix concerns the "backhaul" signal from the wireless receiving device 40 (or more generally the K wireless receiving devices 40); and the third sub-matrix concerns the transmission, by K ' user terminals, of an uplink signal to the set of receive antenna elements 10(Rx) of the wireless communication device 10.

[0119] Thus, when the communication system comprises K wireless transmitting devices 40, K wireless receiving devices 20 and K user terminals, the global channel matrix H for a communication device 10 is then defined such that:

[0120] H = 'SI SI HintSIC.^O ^0-40 ^intk—10 ^intk ~0Ji -1”*10 HintSIC.UL^lQ intk^UL^W intk'^UL^Q ■ intk=K-\,Q^lQ Hintk =Æ-l,l~*10 - ,si ^intUL, O-* 10 HintUL, MO ^IntVL, K-H0 H EU,UL

[0121] with Hintx,y-*10 a notation associated with the channels with which the signals sent are not signals of interest for the corresponding receiving antennas, X the index of the device configured to transmit its "backhaul" signal, and Y the index of the device which receives the signal from the Xth device.

[0122] It is important to note here that the contributions of the communication channel HS] are included in the global channel matrix H, and correspond to the first column vector f Sl]T' This formalization is allowed by the use of a chain Dedicated RF (and receiving antenna elements connected to this dedicated RF chain), as described below.

[0123] It is also important to note that the first row of this global channel matrix H corresponds to the antenna links between all the transmitting antenna elements of the scenario, i.e., those of the communication device 10, the wireless transmitting devices 40, the user terminals 30, and those connected to the dedicated RF chain. The content of the signals received by these antenna elements connected to the dedicated RF chain is of little importance, but is required to be able to carry out the baseband processing mentioned below.

[0124] [Fig. 3] shows an exemplary implementation of a wireless communication device (10) implementing uplink communication, in accordance with the first aspect of the invention.

[0125] As illustrated by [Fig. 3], the communication device 10 comprises a transmission chain 100(Tx) and a reception chain 100(Rx). The transmission chain 100(Tx) includes a constellation modulation block 110 implementing, for example, quadrature amplitude modulation or quadrature phase modulation. This constellation modulation block 110 is connected (directly or indirectly) to a modulation block 130 implementing, for example, OFDM coding ("Orthogonal Frequency-Division Multiplexing" according to English terminology).

[0126] In the uplink communication scenario as illustrated by Figures 1 and 2, the only signal transmitted by the wireless communication device 10 is the backhaul signal ^bhk>-»20- Therefore, only a single RF chain 140 needs to be activated, and a fortiori, the digital precoder 120 is deactivated.

[0127] The modulation block 130 is connected at the output to an RF chain 140, itself connected to an analog precoder 150 to which the transmission antenna elements 10(Tx) are connected.

[0128] This architecture offers the advantage of forming beams by a hybrid beamforming method, which is advantageous in that it offers a compromise between the high spectral efficiency offered by the use of a digital beamforming method, and the low hardware complexity and low power consumption offered by the use of an analog beamforming method.

[0129] The reception chain 100(Rx) includes a plurality of antenna elements of reception 10 (Rx) connected to an analog post-coder 160. This post-coder is connected at the output to a plurality of RF chains (acronym for "Radio Frequency") 170, of a design known per se, each RF chain being itself connected to a modulation block 180 implementing for example OFDM coding. As discussed in more detail below, one of the RF chains 170 is dedicated to the processing of a self-interference signal received following the transmission, by the communication device 10, of the signal intended for the reception device 20.

[0130] The modulation blocks 180 are connected to a digital post-coder 190. Finally, the digital post-coder 190 is connected to a constellation modulation block 200 implementing, for example, quadrature amplitude modulation or quadrature phase modulation.

[0131] Of course, a transmission chain 100(Tx) (respectively a reception chain 100(Rx)), may still include other electronic equipment (filters, etc.), this aspect not being described further here because it is outside the scope of the invention.

[0132] As represented in [Fig.3], the architecture of the RF chains is partially connected ("Partially Connected" according to the Anglo-Saxon terminology). The following developments are however adaptable without difficulty by those skilled in the art to the case where the architecture of the RF chains is fully connected ("Fully Connected" according to the Anglo-Saxon terminology).

[0133] [Fig.4] represents an example of distribution of the sets of reception 10(Rx) and transmission 10(Tx) antenna elements of a wireless communication device 10 comprising five RF reception chains.

[0134] As illustrated in Figure 4, the communication device comprises a set 10(Rx) of transmitting antenna elements of dimension 10 x 4. This set 10(Rx) is subdivided into five subsets of dimension 2x4; • a first RX, SI subset dedicated to the reception of a self-interference signal (SI); • a second RX sub-assembly, BH40 10 dedicated to receiving a signal from the wireless transmission device 40 (here K = 1); • a third RX sub-assembly, UE30-1 dedicated to receiving a signal from a first user terminal; • a fourth RX sub-assembly, UE30-2 dedicated to receiving a signal from a second user terminal; and • a fifth RX sub-assembly, UE30-3 dedicated to receiving a signal from a third user terminal.

[0135] Each of the five sub-assemblies is indirectly connected to an RF chain 170 of the reception chain 100(Rx) of the communication device 10. In other words, this distribution of the set 10(Rx) of transmitting antenna elements into five sub- sets is enabled by the use of at least five RF chains 170. And one of these five RF chains 170 is dedicated to processing a self-interference (SI) signal resulting from the transmission of another signal by the communication device 10.

[0136] The communication device 10 further comprises a set 10(Tx) of transmitting antenna elements of dimension 8x4. This set 10(Tx) is subdivided into four subsets of dimension 2x4; • a first TX subassembly, BH10 20 dedicated to the transmission of a signal to the wireless reception device 20 (here K = 1); • a second TX sub-assembly, UE30-1 dedicated to the transmission of a signal to a first user terminal; • a third TX sub-assembly, UE30-2 dedicated to the transmission of a signal to a second user terminal; and, • a fourth sub-assembly TX,UE30-3 dedicated to the transmission of a signal to a third user terminal

[0137] It is important to note here that the subsets TX, UE30-1, TX, UE30-2 and TX, UE30-3 are not essential in the case of an uplink, since the only signal in transmission is that of the BH10—>20 link.

[0138] [Fig.5] schematically represents modules embedded in a wireless communication device 10, according to an exemplary implementation in accordance with the first aspect of the invention.

[0139] This wireless communication device 10 notably comprises a module M0D_RX and a module MOD_PROC whose functionalities are described with reference to [Fig.6].

[0140] [Fig.6] represents an example of hardware architecture of a wireless communication device (10).

[0141] As illustrated by [Fig.6], the wireless communication device 10 has the hardware architecture of a computer. Thus, the wireless communication device 10 comprises, in particular, a processor 1, a random access memory 2, a read-only memory 3 and a non-volatile memory 4. It further comprises a communication module 5.

[0142] The read-only memory 3 of the wireless communication device 10 constitutes a recording medium as proposed, readable by the processor 1 and on which is recorded a computer program PROG_UL in accordance with the invention, comprising instructions for the execution of steps of the uplink communication method as proposed below. The program PROG_UL defines one or more functional modules of the device, which rely on or control the hardware elements 1 to 5 cited above, and which include in particular: • a module M0D_RX for receiving first signals transmitted by at least one wireless transmission device (40) and at least one user terminal (30), and of a second signal transmitted by at least one transmitting antenna element (10(Tx)) of the wireless communication device (10) and intended for at least one wireless receiving device (20), and • a MOD_PROC module for processing the first and second received signals configured to reduce a power level received by the receiving antenna elements following reception of the second signal, at least one of said RF chains being dedicated to processing the second signal.

[0143] Furthermore, the wireless communication device 10 may also comprise other modules, in particular for implementing particular modes of the full-duplex communication method, as described in more detail later.

[0144] [Fig.7] illustrates, in flowchart form, the main steps of an uplink communication method, according to an exemplary implementation of a first aspect of the invention. This method is implemented by the wireless communication device 10.

[0145] As illustrated by [Fig.7], the uplink communication method comprises a first step S1000 of configuring this wireless communication device 10, which includes sub-steps S1100 and S1200.

[0146] S1100

[0147] Sub-step SI 100 is a step of determining an analog postcoding matrix Wrf which will be used to configure the analog postcoding module 160, and an equivalent analog precoding matrix F.

[0148] The equation for the signals Y received by the receiving antenna elements of the wireless communication device 10 in this uplink scenario is written as follows:

[0149] Y = W%bW$fHFrf„PX+W%bW^ = W“BZ

[0150] with v / \7 the vector representing the A ~ \XBH 1CH2O xUE0> XUEK-1) signals emitted by all transmitters of the communication system, and including those emitted by the transmitting antenna elements 10(Tx) of the communication device wireless 10, P - diag ( \ / P bh 10^20 \}P bh4o-*io? ^P ueü ' matræe diagonal power representative of the power allocated to the signals emitted by each of the transmitters of the communication system, and such that:

[0151] Z =WHKFHFKF,„tPX + W&V.

[0152] According to a particular implementation, the matrix results from the horizontal concatenation of pointing column vectors ek having as their origin the set of transmitting antenna elements (10(Tx)), the at least one wireless transmitting device (40), and the at least one user terminal (30), and pointing to the set of elements receiving antenna (10(Rx)).

[0153] According to a particular implementation, when the architecture of the RF chains is partially connected, these pointing vectors ek are defined such that:

[0154] 1 1 r A ( sin ( 0j +sin ( ) cos ( ) ) 1 ek = a ^A ( ( ^ky~ 1 ) -A ( ) +sin ( ) cos( ) ) , ^A ( ( ^ky- ! ) sin( ^)+( 1 ) sin( ) cos ( «4 ) ),

[0155] with = .......1...... a normalization factor depending on the number of elements transmitting or receiving antenna of the wireless communication device 10, £ a direction index having a value among { BHl0^2& UE^ ..., UEK ,}, $k and the elevation and azimuth of the direction £ 'c number of rows of antenna elements of the set 10(Z¥) dedicated to the direction and mW) the number of columns kJ-l of antenna elements of the set 10(ZY) dedicated to the direction k, with Zx ^{Tx- RW

[0156] The WRF matrix is ​​then constructed by horizontal concatenation of the pointing column vectors ek having as their origin the set of transmitting antenna elements (10(Tx)), the at least one wireless transmitting device (40), and the at least one user terminal (30), and pointing towards the set of receiving antenna elements (10(Rx)).

[0157] The WRF matrix is ​​then written as follows:

[0158] esKk^ 0 ■■■ ...... ...... 0 i 0: esia=K-\} 0: 0 eBH[io-*æ'=o) 0! <>:: 0::: 0 eBHW^k=K-È); ; ; ; oo ■■■ ; Q / iâ -o> 0: 0! ...... eUEW=K-\)\

[0159] with eSI(k=0.Kl) of the pointing vectors of the set of transmitting antenna elements (10(Tx)), eB / / (io-»L=o_Æ-i) of the pointing vectors of the A wireless transmitting devices (40), and eUE(k =0. k) of the pointing vectors of the K user terminals (30).

[0160]

[0161]

[0162]

[0163]

[0164]

[0165]

[0166]

[0167]

[0168]

[0169]

[0170] This VFrf matrix is ​​of dimension x (K + K + K with a number of transmitting antenna elements of the wireless communication device (10), K a number of wireless receiving devices (20) such that K > 1, a number of wireless transmitting devices (40) such that K > 1 and X a number of user terminals (30) such that K > 1- Using such analog post-coding makes it possible to generate an equivalent channel matrix Heq which is square, and which is then of dimension [K + K + K ) x (K + K + K^- The Heq matrix is ​​then written as follows: The equivalent analog precoding matrix Frf^ is obtained by concatenating the pointing vectors of the different transmitters in the communication system. The resulting Frf^ matrix is ​​then written: » ^^ / 740-10 0 0 ■ F RF“ 0 0 b - 44 with IK an identity matrix of dimension K x K', and which represents the fact that the K user terminals do not have the capacity to form beams, since each terminal is equipped with only one antenna. More generally, the equivalent analog precoding matrix Frf^ is written 1 F cBHk=O-^\Q 0 ......... 0 1 0 • * ■ ■ * T 4 ■ • : eBHk=K-1-^10 0 ...... : Frf^ - ■ : 0 eBHu>^a 0 ... : ■ ■ • o ... ; ■ ■ > : : eBÆio^k=Ki : , 0 ... . < .44 S1200 The uplink communication method further comprises a step S1200 of determining a baseband digital post-coding VFBB matrix. It is important to note that obtaining an equivalent channel matrix that is square simplifies the implementation of digital post-coding. The implementation of digital post-coding depends on the effect desired by the system user. Unlike analog postcoding, there are no hardware constraints that induce mathematical constraints on the expression of the digital postcoding matrix W BB.

[0171] According to a particular implementation, the digital post-coding VFBB matrix is ​​determined by applying a zero forcing criterion, and this WBB matrix is ​​then expressed as follows:

[0172] / Wse2F=\vAzr)

[0173] with H the matrix representing a global communication channel, Heg the matrix representing an equivalent communication channel, 1 a normalization factor and AZF an objective matrix of dimension + K ) x (K + K + K"), said matrix AZF corresponding to the horizontal concatenation of K null column vector(s) of dimension KF K ) X 1, and of a matrix MZF of dimension (K + K ) x ( K + K ), the coefficients of the diagonal of said MZF matrix being greater than the other coefficients of said matrix.

[0174] The cancellation of self-interference signals is based on the first K column vectors. According to a particular implementation, the MZF matrix is ​​a diagonal matrix. In this case, the AZF matrix is ​​expressed for example in the form

[0175] ■o ■ ■ 0 1 0 ■ ■■ 0' ■ ■ 0 0 1 ■ 0 ^ZF ~ 0.0 ■ ■ 0 0 ■■■ ■ ■■ 1.

[0176] The cancellation of the self-interference signals is then a strict cancellation since these first A column vectors are null.

[0177] Alternatively, some zero-valued coefficients of the AZF matrix are replaced by arbitrarily small values ​​£. (eg, s = 10'10), this in order to facilitate the calculation of the matrix inversion in the calculation of the WBBZF matrix and to represent a transmission power towards other devices and user terminals which is higher.

[0178] Alternatively, the AZF matrix is ​​adapted so as to cancel the self-interference signal and / or the interference of only certain transmitting parts for which it has for example been determined that they have a significant impact in terms of interference (eg, whose received power of the interference signal is greater than a predetermined threshold).

[0179] S2000 - S500

[0180] The uplink communication method further comprises a step S2000 for simultaneous reception of signals from user terminals 30 and the wireless transmitting device 40.

[0181] During a step S3000, an analog post-coding is implemented on these signals received by applying the analog post-coding matrix VF, so as to obtain a plurality of streams at the output of the analog post-coder 160 of the transmission chain 100(Tx).

[0182] Then, during a conversion step S4000, each of the output streams of the analog post-coder 160 is mixed / filtered then converted into a digital stream. This step is notably implemented by an RF chain 170 of the reception chain 100(Rx). It is important to note here that one of the RF chains 170 is dedicated to the processing of the self-interference signal.

[0183] The communication method further comprises a step S5000 of digital post-coding of the digital streams by applying the digital post-coding matrix ^bb. This step is implemented by the digital post-coder 190 of the transmission chain 100(Tx).

[0184]

[0185] Downlink communication

[0186] The invention has so far been described in the case of an uplink communication between the wireless communication device 10 and the user terminals 30. Figures 8 to 13 this time illustrate the case of a downlink communication, where the effect of self-interference is reduced or even cancelled by processing at the level of the transmission chain 100(Tx) of the wireless communication device 10.

[0187] Figure 8 is an example of a communication system in which a downlink communication method is implemented. The system is similar to that illustrated in Figure 1, and is therefore not described again, for the sake of brevity. The only difference concerns the Hue, DL communication channel discussed with reference to [Fig.9].

[0188] Figure 9 is a detailed view of Figure 8 in which the communication channels considered in connection with the wireless communication device 10 are considered. The channels H si, Hbh40^}0 and Hbha^io are similar to those described with reference to [Fig.2], and are therefore not described again, for the sake of brevity.

[0189] The only difference concerns the communication channel, the Hue communication channel, dl (which replaces the Hue channel, ul) and which is this time directed from the network of transmitting antenna elements 10(Tx) of the wireless communication device 10 towards the user terminals 30.

[0190] Hue communication channel, dl

[0191] In practice, the signals transmitted between a user terminal 30 and a communication device such as a base station are frequently reflected by reflectors

[0192]

[0193]

[0194]

[0195]

[0196] before reaching their target. For this, the HUE DL communication channel is modeled as a communication channel without direct line of sight. Furthermore, since user terminals are typically at a certain distance (e.g., from a few tens of meters to around thirty kilometers) from the base station to which they are attached, the signals passing through these channels are modeled by a plane wave model. The construction of the matrix dl representative of the channel between the communication device 10 and the user terminals is for example implemented using a method based on ray tracing. More precisely, for each user terminal, a direct beam emitted by the communication device 10 towards the given user terminal 30 is defined, then L - 1 other beams are constructed whose Direction of Departure DoD is separated by an angle of A2 and _ both in elevation and in azimuth relative to the main beam. To model the environment of the user terminals, it then results that for each user terminal 30, i beams are emitted, and the angle of arrival DoA of these f beams is between [-7T, tt] for the elevation and [0; 2^] for the azimuth. As mentioned previously with reference to Figure 1, for the purpose of simplifying the description, it is considered that each user terminal 30 is equipped with only one antenna (e.g., isotopic). Also, the number of receiving antenna elements to be considered corresponds to the number (k") of user terminals connected to the wireless communication device 10, and the channel matrix is ​​then constructed by concatenation of column vectors, each column vector representing one of the K user terminals. The u,th row of the channel matrix HlJE DL is defined as follows: H UEPLp - 1 <eTxll ( Of ) , with L the number of paths induced by the presence of reflectors, ai the complex attenuation coefficient for the lth path, ri the delay associated with the fth path, e'r^ the pointing vector of the set 10(Tx) of transmitting antenna elements of the communication device 10 of dimension x 1 associated with the terminal user, 0i and ¢l the azimuth and elevation angles of the DoD of the female path. The dimension of the channel matrix is ​​then g” x , with the number of transmitting antenna elements of the communication device 10 dedicated to the transmission of data to user terminals.

[0197] Unlike the cancellation solution proposed for uplink communication (with reference to the first aspect of the invention), an RF chain of the reception chain 100(Rx) which is dedicated to the self-interference signal is not ne- necessary to cancel downlink self-interference.

[0198] Also, the global channel matrix H of dimension

[0199] ■ SI HBH 10^2.0 SI ' # UEtr^BH. Hbh^ue Hue,dl .

[0200] More generally, when the communication system comprises K wireless transmitting devices 40, K wireless receiving devices 20 and K user terminals, the global channel matrix H for a communication device i is then defined such that:

[0201] H-' SI ^HW-0 HintksO.H'ï ^inlk=l. 1 in(I <sK-\ .10 SI Hitlt[JE^ / c=0 H inîUEA^ksl àiJk=Oj-*K-l intk= 1, i 0~*k=K-1 ‘ ' HiMk=KAA^k=K-l HintUE,lQ^K-l intk- !, 1 E Hintk=K-lAQ^UE Huepl

[0202] [Fig. 10] shows an exemplary implementation of a wireless communication device (10) implementing downlink communication with user terminals.

[0203] According to the invention, the communication device 10 has an architecture configured to transmit and receive signals in full-duplex mode via antenna elements.

[0204] As illustrated by [Fig. 10], the communication device 10 comprises a transmission chain 100(Tx) and a reception chain 100(Rx). The transmission chain 100(Tx) includes a constellation modulation block 110 implementing, for example, quadrature amplitude modulation or quadrature phase modulation. This constellation modulation block 110 is connected to a digital precoder 120. The digital precoder 120 is itself connected at the output to a plurality of modulation blocks 130 implementing, for example, OFDM coding ("Orthogonal Frequency-Division Multiplexing" according to English terminology). Each modulation block 130 is connected at the output to an RF chain 140, of design known per se, and the RF chains are connected to an analog precoder 150 to which the transmission antenna elements 10(Tx) are connected.

[0205] This architecture offers the advantage of forming beams by a hybrid beamforming method, which is advantageous in that it offers a compromise between the high spectral efficiency offered by the use of a digital beamforming method, and the low hardware complexity and low power consumption. energy offered by the use of an analog beamforming method.

[0206] The reception chain 100(Rx) includes a plurality of reception antenna elements connected to an analog post-coder 160. This post-coder is connected at the output to a plurality of RF chains 170, each of which is connected to a modulation block 180 implementing, for example, OFDM coding. This modulation block 180 is connected (directly or indirectly) to a constellation modulation block 200 implementing, for example, quadrature amplitude modulation or quadrature phase modulation.

[0207] In the scenario discussed with reference to [Fig.8] and [Fig.9], the only signals expected by the reception chain 100(Rx) of the communication device 10 are the signals coming from the wireless transmission device 20. This is the reason why a single RF chain 170 and the modulation block 180 to which it is connected are activated - the other chains then being represented in the form of dotted lines -. And a fortiori, since only one RF chain is required, it can be directly connected to the block 200, without a digital post-coder 190 being used.

[0208] Of course, a transmission chain 100(Tx) (respectively a reception chain 100(Rx)), may still include other electronic equipment (filters, etc.), this aspect not being described further here because it is outside the scope of the invention.

[0209] As represented in [Fig. 10], the architecture of the RF chains is partially connected ("Partially Connected" according to the Anglo-Saxon terminology). The following developments are however adaptable without difficulty by those skilled in the art to the case where the architecture of the RF chains is fully connected ("Fully Connected" according to the Anglo-Saxon terminology).

[0210] Finally, it is also important to recall that unlike the cancellation solution proposed with reference to the first aspect of the invention, an RF chain on the reception chain side 100(Rx) and which is dedicated to the self-interference signal is not necessary to cancel the self-interference in the uplink.

[0211] [Fig. 11] schematically represents modules embedded in a wireless communication device (10), according to an exemplary implementation of the invention.

[0212] This wireless communication device 10 notably comprises a MOD_FH module and a MOD_TX module whose functionalities are described with reference to [Fig. 12],

[0213] [Fig. 12] represents an example of hardware architecture of a wireless communication device (10).

[0214] As illustrated by [Fig. 12], the wireless communication device 10 has the hardware architecture of a computer. Thus, the wireless communication device 10 comprises, in particular, a processor 1, a random access memory 2, a read-only memory 3 and a non-volatile memory 4. It further comprises a communication module 5.

[0215] The read-only memory 3 of the wireless communication device 10 constitutes a recording medium as proposed, readable by the processor 1 and on which is recorded a computer program PROG_DL according to the invention, comprising instructions for the execution of steps of the downlink communication method as proposed below. The program PROG_DL defines one or more functional modules of the device, which rely on or control the hardware elements 1 to 5 cited above, and which include in particular: • a hybrid beamforming module (MOD_FH) including a baseband precoding sub-module by applying an analog precoding FBB matrix; and, • a transmission module (MOD_TX), of a signal intended for said at least one wireless reception device (20) and of a signal intended for said at least one user terminal (30), the transmission causing the reception, by the set of reception antenna elements (10(Rx)) of self-interference signals, said FBB matrix being determined so as to minimize the mean square error between a plurality of transmitted signals and a plurality of received signals in said system, and by applying the following constraints: • the signals are transmitted in accordance with a transmission power less than or equal to an available power; • the first row of a resulting matrix Heq FBB is a vector of which at least one of the coefficients is less than a threshold value, with Heq a ​​matrix representative of an equivalent communication channel, and M the conjugate of the matrix M.

[0216] Furthermore, the wireless communication device 10 may also comprise other modules, in particular for implementing particular modes of the full-duplex communication method, as described in more detail later.

[0217] [Fig. 13] illustrates, in flowchart form, the main steps of a downlink communication method, according to an exemplary implementation of the invention. This method is implemented by the wireless communication device 10.

[0218] As illustrated by [Fig. 13], the downlink communication method comprises a first step S100 of configuring this wireless communication device 10, which includes sub-steps S110 and S120.

[0219] S110

[0220] Sub-step SI 10 is a step of determining an analog precoding FRF matrix which will be used to configure the analog precoding module 150, and an equivalent RF coupler. It is important at this stage to recall that a chain Additional RF 170 is not required to cancel the self-interference signal. Thus, the equation of the signals received Y by all receiving antenna elements of the communication system in the field of demodulation (frequency or temporal) in this downlink scenario is written as follows:

[0221] Y = W^HF^F^X + + Ysol

[0222] with _ [ ' ' 7 the size vector (A" + AT + Æ x 1 æ- representative of all the receiving antenna elements of the communication system (including the receiving antenna elements of the wireless communication device 10), the equivalent post-coding matrix of size v regrauPe all the Rx k 0+j 0^. + K jx K + K + KI pointing vectors of all receiving parts of the scenario, the adjoint matrix of a matrix, H the global channel matrix of size ( «+k- jx teiie defined in s“ü°n t AA, / v^1U AA.-1U A f IX "Global Channel Matrix", FRF an analog precoding matrix of size X (K + K y a vector of size ( K + K ) X 1 which groups the signals sent by the wireless communication device 10, FBB a digital precoding matrix of size q. jx (K + K y a diagonal matrix grouping the power allocated for each signal transmitted, X the vector representing the signals transmitted by the wireless communication device 10, X the vector of size OC 1<« + K jx 1 «Putative of the noises received by each receiving antenna element of the set of antenna elements 10(Rx), vnn]T the vector representing the signals of interest for the self ~ U' wireless communication device 10.

[0223] It is therefore possible to "precode" and "postcode" the global channel using the matrices Frf and H RFj;q. According to a particular implementation, only phase shifters and adders are present in the system, and the coefficients of these two matrices are of modulus equal to 1.

[0224] According to a particular implementation, the matrix Frf results from the concatenation of pointing column vectors ek, each vector being representative of a phase to be applied to a signal at the input of at least one of said transmitting antenna elements.

[0225] According to a particular implementation, when the architecture of the RF chains is partially connected, these pointing vectors ek are defined such that:

[0226] ek = a g- jn (sin(0) +sin()cos[ÿ)) , ( ( Mv -1 )sin ( 0j + ( Mrr 1 ) «in ( h )cos ( ).),

[0227] with a — —l— a normalization factor depending on the number of MT elements transmitting antenna of the wireless communication device 10, & an index of direction having a value among {BZ / I0_»2o • ■ • ' 1} ' A- ct the elevation and the azimuth of the direction M^y The number of rows of antenna elements of the set 10(ZY) dedicated to the direction k, and the number of columns of elements antenna of the set IO(ZA) dedicated to the direction k, with Zx c{7\; R^.

[0228] The matrix Frf is then constructed by vertical concatenation of the pointing vectors ek which point towards the wireless receiving device 20 and towards the k" user terminals 30 connected to the wireless communication device 10.

[0229] The matrix / ^rf is then written as follows:

[0230] ' eBHi0^k=0 $ ■" ...... 0 0 ......... ; ■ ■ ■ ■ 0 ■ ■ ■ : : ... 0 „ ... : ; ......... 0 . $ ■" ■" ■" 0

[0231] with eBHto-»2O the pointing vector of dimension x 1 P°intant towards the set of receiving antenna elements of the wireless receiving device 20, ®UEk =0..K the pointing vector of dimension °)r „ x T^ÏjEk । pointing to the dif different directions of the K user terminals. The resulting Frf matrix is ​​then dimension x (k" + K) with ^0°) the number of antenna elements transmission of the communication device 10 dedicated to the transmission of signals to the K wireless reception devices 40 and to the user terminals 30.

[0232] To obtain the VFrr^ matrix, the pointing vectors of the different receiving devices of the communication system are concatenated. The resulting VFrr^ matrix is ​​then written:

[0233] 'e BH, L=0-*10 0 0 ■■ SBH,kK^\Q $ 0 1 ■ 0 ^BH, ■ : 0 ... ■

[0234] with Ig m 1 the 0 ...... identity matrix of dimension K x K • eBH, ItHsK-i 0 I„ A 1

[0235] The matrix I illustrates the fact that the user terminals all have a unique antenna and therefore do not have the ability to perform beamforming.

[0236] Alternatively, each user terminal comprises several antennas or several RF chains and therefore has the power to perform beamforming. In this case, the shape of the VFRpeq matrix is ​​similar to that previously discussed, but the identity matrix Ig is replaced by the pointing vectors of

[0237] each user terminal.

[0238] The equivalent channel matrix is ​​then written:

[0239] Heq = WrfHFrf.

[0240] S120

[0241] The downlink communication method further comprises a step S120 of determining a baseband digital precoding FBB matrix. As mentioned above, interference cancellation is done only with specific baseband processing - eg, by considering a well-chosen precoding FBB matrix -.

[0242] The baseband digital precoding FBB matrix is ​​determined by solving the problem formalized by the following Ot equations:

[0243] argminj (XK) F BB S.LE || F kr PX Heq FBB, Vk e (0. . (¾) V / e{0, ...,K + K-1}

[0244] with J a cost matrix (or function) chosen according to the desired objective, X the vector of dimension ( 4- x 1 representing all the signals emitted (eg, the signals emitted by the wireless communication device 10 and those emitted by the K wireless transmission devices 40, Pp the total available power, jk =

[0245]

[0246]

[0247]

[0248]

[0249]

[0250]

[0251]

[0252]

[0253]

[0254]

[0255] (O, ... 1, O)7 The vector of dimension (K + K + K"}* comprising only a "1" at position k and "0"s elsewhere, and (q the vector of dimension (A? + K ) x 1 with only one "1" at position / and "0"s elsewhere, E the mathematical expectation, and M the conjugate of the matrix M. The vector X corresponds to the vector X but also includes the signals from the wireless transmitting device(s) 40. Therefore, the vectors and X are of the same dimension, and a subtraction of these two vectors is therefore possible. By construction, the meaning of the constraint fL) is explained as follows: whatever the digital precoding FBB matrix chosen, it is not possible to exceed the total power Pp available for the emission of beams by the wireless communication device 10. The meaning of the constraint (Cfcf is explained as follows: the coefficient located at the kth row and the lth column of the resulting matrix HeqFBB must be equal to "0", so that the effect of the equivalent channel of the transmitter on the kth receiver is completely cancelled. Alternatively, this coefficient is not equal to "0", but equal to a predetermined value (eg, a value included in the interval [JO'10; 10'6])- It therefore follows that it is sufficient to determine the coefficients k and l to cancel the effect of the self-interference signal, and / or cancel the other interfering components in origin of other wireless transmitting devices 40. Depending on a particular implementation, the objective is to minimize a qua error average dratic between signals emitted by wireless transmitting devices and resulting signals received by said wireless communication device 10. In this case, argminj ( X - K ) = arsxninE Fbb The PX-Y II 2 11 II p with E the mathematical expectation, and || . || ^ the norm of Frobenius. By applying the well-known Lagrange multiplier method, the FBB precoding matrix is ​​then expressed as follows: FBB, MM SEC = {HleqH eq + ÀqI ) H^qAM MSEC, with H a matrix representing a global communication channel, a matrix representing an equivalent communication channel, A) a Lagrange factor, ÀMMSEC an objective matrix of dimension ( 7^ + K 4-K" + 1) x (K + K + K y with a number of wireless receiving devices (20) such that K > 1, x a number of wireless transmitting devices (40) such that K > 1 and K a number of user terminals (30) such that K > 1- The matrix corresponds for example to the vertical concatenation of a diagonal matrix of dimension 4. '4. / fj x (K + K 4- KX and a row vector of dimension ] x (K + K + K of which each coefficient represents a cancellation constraint of a self-interference signal.

[0256] According to a particular implementation, this diagonal matrix is ​​an identity matrix, and the Avimsec matrix is ​​then expressed in the form

[0257] ' ' "k ■ ' ' ■ ■ -¼ 1 0 ■ ■ 0 &mmse ~ 0 1 ■ ■ 0 ■ ■ ■ . o , 0 ■■■ ■ ■ 1

[0258] with A-ur Lagrange factors corresponding to the cancellation constraints (ckJ ) and whose values ​​depend on the coefficients of the equivalent channel matrix Heq, and the value of 20.

[0259] According to a particular implementation, the first row of the resulting matrix ^BB is a zero vector, and the first row of the matrix AMMSEC is also a zero vector.

[0260] The role of this first line corresponding to a zero line vector is to cancel the contribution of the signals emitted by the transmitting antenna elements 10(Tx) and received by the receiving antenna elements 10(Rx) of this same wireless communication device 10. The role of the diagonal matrix is, for its part, to guarantee that each receiver of the communication system receives a signal without interference caused by another receiver of the communication system.

[0261] Alternatively, the zeros of the matrix are replaced by arbitrarily small values ​​p (eg, s — 1O'! 0)-

[0262] Alternatively, the matrix Aa1mse is adapted so as to cancel the self-interference signal and / or the interference of only certain transmitting parts for which it has for example been determined that they have a significant impact in terms of interference (eg, whose received power of the interference signal is greater than a predetermined threshold).

[0263]

[0264] S200 - S500

[0265] The downlink communication method further comprises a step S200 of digital precoding in baseband by applying the digital precoding FBB matrix determined during step S120, so as to obtain a plurality of streams at the output of the digital precoder. This step is implemented by the digital precoder 120 of the transmission chain 100(Tx).

[0266] Then, during a conversion step S300, each of the streams is converted into an analog stream and an analog mixing and / or filtering step of said analog stream are implemented, so as to obtain an RF data stream. This step is implemented by an RF chain 140 of the transmission chain 100 (Tx).

[0267] The communication method further comprises a step S400 of analog precoding of the RF data streams by applying the analog precoding matrix Frf determined during step S110, so as to obtain signals in the form of beams directed towards the wireless reception device 20 and the user terminals 30. This step is implemented by the analog precoder 150 of the transmission chain 100(Tx).

[0268] Finally, the method comprises a step S500 of simultaneously transmitting the following signals in the form of beams: • a signal directed towards the wireless receiving device 20; • signals directed to each of the user terminals 30 (downlink).

[0269] The invention has so far been described in the context of mobile telecommunications networks (e.g., 5G). It nevertheless remains applicable to other types of wireless networks (e.g., Wi-Fi, etc.). The invention also applies to mesh networks and / or distributed MIMO topologies.

[0270] The invention could also be applied in a context of joint communication and detection technologies ("Integrated Sensing and Communication" (ISAC) according to English terminology) introduced for 6G in an operating mode where the radar and the communication are located on the same wireless communication device operating in full-duplex.

[0271] Finally, the invention could also be implemented in order to make communications secret, but also in order to generate local white zones.

Claims

Claims

1. A full-duplex communication method implemented by a wireless communication device (10) comprising a set of transmitting antenna elements (10(Tx)), a set of receiving antenna elements (10(Rx)) and a plurality of RF chains, each RF chain being connected to at least one of said receiving antenna elements (10(Rx)), the method comprising: • reception (S2000), by at least one receiving antenna element (10(Rx)) of the wireless communication device (10), of first signals transmitted by at least one wireless transmitting device (40) and at least one user terminal (30), and of a second signal transmitted by at least one transmitting antenna element (10(Tx)) of the wireless communication device (10) and intended for at least one wireless receiving device (20), and • processing (S3000, S4000,S5000) of the first and second received signals aimed at reducing a power level received by the receiving antenna elements following the reception of the second signal, at least one of said RF chains being dedicated to the processing of the second signal.,

2. The communication method according to claim 1, wherein the processing comprises an analog post-coding step (S3000) by applying a constructed analog post-coding matrix (SI 100) by concatenating pointing column vectors originating from the set of transmitting antenna elements (10(Tx)), the at least one wireless transmitting device (40), and the at least one user terminal (30), and pointing to the set of receiving antenna elements (10(Rx)).

3. A communication method according to claim 2, wherein the analog post-coding VFRF matrix is ​​of dimension X (K + K + K \ with a number of transmitting antenna elements of the wireless communication device (10), K a number of wireless receiving devices (20) such that K > 1, a number of wireless transmitting devices (40) such that K > 1 and K a number of user terminals (30) such that K > 1-

4.

5.

6.

7.

8. A communication method according to claim 2 or 3, wherein the analog post-coding WRF matrix is ​​of the form es / c(fc=o) 0 ■ ' ' ' ' ■ ■ ' ■ ...... 0 i 0 \ ■■■ ......... ...... ; : : 0 ■■■ ■■■ ...... : : : 0 eBn( rw=o) 0 ...... : ; ; ; of ■■■ ...... ; : : : : 0 ;<> -a .-.au 0 : : : : : : 0 ® : ; ; ; ; ; ; of ! 0 ■■■ ■■■ ■■■ ■■■ ■■■ “■ ■■■ <?(7E(Ï=A<1)! with eSIC(k=QK-ï) of the pointing vectors of the set of transmitting antenna elements (10(Tx)), eBH(i^k=oK-ï) of the pointing vectors of the K wireless transmitting devices (40), and eUE(k =o. k ) of the pointing vectors of the k ' user terminals (30). A communication method according to any one of claims 1 to 4, wherein the processing further comprises a digital postcoding step (S5000) by applying a digital postcoding VFBB matrix, said W BB matrix being determined (S1200) by applying a zero-forcing criterion. Communication method according to claim 5, in which the digital post-coding matrix VFefî is defined such that: WBBZF ~ ylAzpHec^HeqHe(^ j , with H a matrix representative of a global communication channel, Heq a ​​matrix representative of an equivalent communication channel, 1 a normalization factor and AZF an objective matrix of dimension + K j X (K + K + K said AZF matrix resulting from a concatenation of K zero column vector(s) of dimension ^K+K^ X 1, and of a MZF matrix of dimension (K + KX ( K + K the coefficients of the diagonal of said MZF matrix being greater than the other coefficients of said matrix. Communication method according to claim 6, in which the MZF matrix is ​​a diagonal matrix. Communication method according to any one of claims 1 to 7, the wireless communication device (10), the at least one wireless receiving device (20) and the at least one wireless transmitting device (40) being base stations.

9. A computer program comprising instructions for implementing a communication method according to any one of claims 1 to 8, when said program is executed by a computer.

10. A computer-readable recording medium having a computer program recorded thereon according to claim 9.

11. Wireless communication device (10) configured to communicate in full-duplex, and comprising: • a set of transmitting antenna elements (10(Tx)); • a set of receiving antenna elements (10(Rx)); • a plurality (K) of RF chains, each RF chain being connected to at least one of said receiving antenna elements (10(Rx));• a module (MOD_RX) for receiving first signals transmitted by at least one wireless transmission device (40) and at least one user terminal (30), and a second signal transmitted by at least one transmission antenna element (10(Tx)) of the wireless communication device (10) and intended for at least one wireless reception device (20), and • a module (MOD_PROC) for processing the first and second received signals configured to reduce a power level received by the reception antenna elements following reception of the second signal, at least one of said RF chains being dedicated to processing the second signal.;

12. A method of full-duplex communication in a system including a wireless communication device (10), at least one wireless receiving device (20), at least one user terminal (30) and at least one wireless transmitting device (40), the wireless communication device (10) comprising a set of receiving antenna elements (10(Rx)) and a set of transmitting antenna elements (10(Tx)), the method being implemented by the wireless communication device (10) and comprising: • hybrid beamforming including baseband precoding (S400) by applying an analog precoding FBB matrix; and, • transmission (S500), by the set of antenna elements transmission (10(Tx)) and in the form of beams, of a signal intended for at least one wireless receiving device (20) and of a signal intended for at least one user terminal (30), the transmission causing the reception, by the set of receiving antenna elements (10(Rx)) of self-interference signals, said FBB matrix being determined so as to minimize a cost function between a plurality of signals transmitted and a plurality of signals received in said system, and by applying the following constraints: • the signals are transmitted (S500) in accordance with a transmission power less than or equal to an available power; • the first row of a resulting matrix Heq FBB is a vector of which at least one of the coefficients is less than a threshold value, with Hef? a matrix representing an equivalent communication channel, and M the conjugate of the matrix M.

13. The communication method of claim 12, wherein the cost function corresponds to the mean square error, and the precoding FBB matrix is ​​defined such that: F BB, MM SEC — ( H eqHeq + 2qZ HeqAMMSEC> with H a matrix representative of a global communication channel, Heq a ​​matrix representative of an equivalent communication channel, a Lagrange factor, and AMMSEC an objective matrix of dimension (K + K + K + ^x(K + K + K'} with K a number of devices) of wireless reception (20) such that K > 1, a number of devices) of wireless transmission (40) such that K > 1 and K a number of user terminals (30) such that K > 1, said matrix AMMsec corresponding to the vertical concatenation of a diagonal matrix of dimension + K q. x (K + K + K and a row vector of dimension £ x (K + K + K ) each coefficient of which represents a constraint of cancellation of a self-interference signal.

14. The communication method of claim 13, wherein the first row of the resulting matrix Heq FBB is a zero vector, and the first row of the matrix AMMSEC is a zero vector.

15. A communication method according to one of claims 12 to 14, further comprising determining (S 120) said analog precoding matrix F BB by said wireless communication device (10).

16. Communication method according to any one of claims 12 to 15, further comprising a step of determining (SI 10) an analog precoding FRF matrix by concatenation of K + K pointing column vectors which point towards the at least one wireless reception device (20) and towards the at least one user terminal (30), one of said vectors being representative of a phase to be applied to a signal at the input of at least one of said transmitting antenna elements.

17. A communication method according to any one of claims 12 to 16, further comprising a step of determining an analog post-coding equivalent RF coupler VF by concatenating pointing column vectors between the K wireless transmitting devices (40) and the set of receiving antenna elements (10(Rx)), between the set of transmitting antenna elements (10(Tx)) and the K wireless receiving devices (40) and between the set of transmitting antenna elements (10(Tx)) and the user terminals.

18. A communication method according to any one of claims 12 to 17, wherein said self-interference signals are represented by a spherical wave pattern.

19. A communication method according to any one of claims 12 to 18, wherein the wireless communication device (10) and the at least one wireless receiving device (20) are base stations, and the signal between the wireless communication device (10) and the at least one wireless receiving device (20) is modeled by a plane wave model using a direct line-of-sight communication channel.

20. A communication method according to any one of claims 12 to 19, wherein the wireless communication device (10) is a base station, and the signal between said wireless communication device (10) and the at least one user terminal is modeled by a plane wave model using a non-line-of-sight communication channel.

21. Communication method according to one of claims 12 to 20, further comprising a step of modeling a global communication channel including: • a first communication channel - called self-interference - between the set of transmitting antenna elements (10(Tx)) and the set of receiving antenna elements (10(Rx)) of said wireless communication device (10), • a second communication channel between the set of transmitting antenna elements (10(Tx)) and the K wireless receiving devices (20), and, • a third communication channel between the set of transmitting antenna elements (10(Tx)) and the K user terminals (30), said global communication channel being represented by a matrix H comprising: a first sub-matrix of dimension „„ x + ^TX UE ) rePæsenta^ve of the first communication channel, with .... the number of receiving antenna elements of the wireless communication device (10) dedicated to receiving signals from the K wireless transmitting devices (40), M^x BH 'C number of transmitting antenna elements of the wireless communication device (10) dedicated to transmitting signals to the K wireless receiving devices (20) and the number of transmitting antenna elements of the wireless communication device (10) dedicated to transmitting signals to the K user terminals (30) a second sub-matrix of dimension a. / zcu) x RX.ISU BH 4. l rE ) representative of the second communication channel, with mW TT the number of elements rx, rh of receiving antenna of a wireless receiving device k (20) dedicated to the reception of signals, and, a third dimension sub-matrix M^x^n + Mtx UEs) rcPæscnlalivc of the third communication channel, with ) the number of element(s) MRX antenna of a user terminal k' dedicated to the reception of signals.

22. A computer program comprising instructions for implementing a communication method according to any one of claims 12 to 21, when said program is executed by a computer.

23. A computer-readable recording medium having a computer program recorded thereon according to claim 22.

24. Wireless communication device (10) configured to communicate in full-duplex in a system including a wireless communication device (10), at least one wireless receiving device (20), at least one user terminal (30) and at least one wireless transmitting device (40), the wireless communication device (10) comprising: • a set of receiving antenna elements; • a set of transmitting antenna elements; • a hybrid beamforming module (MOD_FH) including a baseband precoding sub-module by applying an analog precoding F BB matrix;and, • a transmission module (MOD_TX), of a signal intended for said at least one wireless reception device (20) and of a signal intended for said at least one user terminal (30), the transmission causing the reception, by the set of reception antenna elements (10(Rx)) of self-interference signals, said FBB matrix being determined so as to minimize the mean square error between a plurality of transmitted signals and a plurality of received signals in said system, and by applying the following constraints: • the signals are transmitted in accordance with a transmission power less than or equal to an available power; • the first line of a resulting matrix Heq FBB is a vector of which at least one of the coefficients is less than a threshold value, with £?e; <!--?une matrice représentative d’un canal de communication équivalent, et M le conjugué de la matrice M.<br--> 44

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