EP2747328B1 - Method for jamming communications in an open-loop controlled network - Google Patents

Description

The invention relates to a scrambling method with optimization of efficiency and limitation by open-loop control of fratricidal effects on telecommunications stations associated with a communications network to be preserved.

The method according to the invention is applied, for example, to scramble certain communication links chosen between entities external to the network to be preserved while maintaining the communication links in the communications network.

The joint use by the same force of communications and jammer networks (or jammer networks) in a theater of operations in the broad sense, and particularly in land convoys, in aircraft squadrons and in flight squadrons. vessels, is often severely penalized by the lack of precise control of the effects induced by the jammer (s) on the signal station (s) of the force network (s).

The technical problem to be solved for the transmission networks and the jammers used jointly is to limit the fratricidal effects of the jammers on the transmission stations, while guaranteeing a minimum efficiency of the jamming on the targets or on the sectors of interest of the theater. .

A first optimization process described in the applicant's patent application FR 11 03 578 is based on the implementation of centralized closed-loop control. This method responds to the problem by resorting to a master jammer station, which may not be suitable for all technical and operational situations. There is currently a need for a method to solve the technical problem in open loop, implementing decentralized decisions at the level of each transmitting and receiving station.

The document EP 0 082 055 relates to waveforms of the alternate and FH type, with an approach of the “free channel search” type to promote the establishment and maintenance of a radiocommunication, by avoiding jammers, a priori unknown. The document US7873095 describes a solution to eliminate or mitigate the fratricidal effects of interference. The document US2008239980 describes a solution for mapping the fratricidal effects of interference.

Definitions :

Jammer : emission system capable of emitting a signal intended to prevent the operation of all or part of the equipment using the electromagnetic spectrum (transmission stations, radar or navigation systems present in the theater of operation). A scrambler is designated in the remainder of the description by the letters Br, the scrambling signal by b, the scrambling signal vector by B.

Jammer network : a coordinated set of emission systems suitable for transmitting signals intended to prevent the operation of all or part of the equipment using the electromagnetic spectrum present in the theater of operation.

“Friend” or “ friend” transmission station: transmission station defined as part of the communications system to be preserved and to be protected from the effects of interference.

“Friend” or “friend” transmission network : an interconnectable set of “friend” transmission stations.

Friend emission: emission coming from a friend station or from a friendly jammer. “Target” equipment: equipment defined as to be affected by the interference.

Communicating jammer: jammer equipped with a "friend" transmission station. Network of communicating jammers: network of jammers equipped with “friendly” transmission stations, constituting a sub-network of friendly transmissions.

Jamming of a target equipment : Emission of a signal or several signals, from a jammer or from a jammer network, so that the target equipment is prevented from implementing or maintain its service.

Jamming of a geographical area : Emission of a signal or several signals, from a jammer or from a jammer network, so that any target equipment present in the geographical area is prevented from setting up or maintaining his service.

Signal detection : ability to decide on the presence of a friendly broadcast or from an external entity and to intercept the signal. This detection is carried out in the band and the duration of analysis of one or more interceptors, analysis module or detection function or "sensing" which can be, for example, hosted by friendly transmission stations or in direct connection. with friendly posts.

Detection of a transmitter : ability to decide on the presence of a transmitter in the theater by detecting the signal (s) it transmits.

Location of a transmitter : ability to decide the location of a transmitter in the theater by detecting the signal or signals it transmits.

SISO : single input single output: refers to a transmission system with one transmitting channel Tx, one receiving channel Rx.

SIMO : single input multiple output: refers to a transmission system with one Tx channel, N Rx channels.

MISO : Multiple Input, Single Output: refers to an emission system with M Tx channels, one Rx channel.

MIMO : Multiple Input, Multiple Output: refers to an emission system with M channels Tx, N channels Rx.

CIR: Channel Impulse Response: refers to the impulse response of the transmission channel, considered as a finite response filter.

The term matrix refers to a channel matrix.

The field of jamming has been the subject of many works and inventions. However, the fratricidal effects are still rather poorly treated in the developments known to date. In general, the constraints associated with the implementation of the methods and systems known to the Applicant have in particular the effect of drastically limiting the ranges and the number of simultaneous friendly radiocommunications, or even preventing the use of friendly radiocommunications.

The object of the present invention relates, in particular, to a method which will make it possible to effectively limit the fratricidal effects with a flexibility and a sufficient range, to simultaneously allow the scrambling of the targets or areas to be scrambled and the operation of communications between friendly stations in an operational context.

• les brouilleurs suivent des plans de fréquence, motifs temporels et formes d'ondes connus des émetteurs/récepteurs amis, ou aisément reconnaissables à l'analyse in situ parmi un ensemble connu à l'avance,
• les émetteurs amis mettent en œuvre des séquences de signaux détaillées dans la suite de la description,
• les récepteurs amis puissent réaliser les mesures sur les signaux de brouillage et les signaux amis pour élaborer une situation de brouillage locale et une situation de réception locale, et pour décider de la meilleure stratégie d'émission/réception pour les liens de communication en cours ou en cours d'établissement.

The invention can be implemented on friendly stations employing multiple waveforms provided that:

• the jammers follow frequency plans, time patterns and waveforms known to friendly transmitters / receivers, or easily recognizable by in situ analysis among a set known in advance,
• the friendly transmitters implement signal sequences detailed in the remainder of the description,
• friendly receivers can perform measurements on interference signals and friendly signals to work out a local interference situation and a local reception situation, and to decide on the best transmission / reception strategy for the current communication links or being established.

• E₀ : Etablir une situation de réception locale : au niveau de chacune des N plateformes de réception amies mesurer, E₁, les signaux de communication Su amis reçus par lesdites plateformes en provenance des M émetteurs amis, à partir desdites mesures, pour chacune des N plates-formes de réception amies, estimer, E₂, les M niveaux utiles reçus et les M canaux de propagation utiles, N*M estimées,
• E₃ : Etablir une situation de brouillage locale : au niveau de chacune des N plateformes amies de réception mesurer, E₄, les signaux de brouillage reçus par lesdites plateformes de réception amies en provenance des J brouilleurs, à partir des mesures des signaux de brouillage, pour chacune des N plates-formes de réception amies, estimer, E₅, les J niveaux de brouillage fratricides reçus et les J canaux de brouillage fratricides, N*J estimées en tout,
• connaissant a priori les formes d'ondes des signaux de brouillage et les paramétrages associés, à partir des états de la situations locale de brouillage établie par chacune des N plateformes réceptrices sur les J signaux provenant des J brouilleurs, à partir de la situation locale de réception établie par chacune des N plateformes réceptrices sur les signaux de communication utiles Su, déterminer pour chacune des M plateformes émettrices amies et pour chacune des N plateformes réceptrices amies, au moins un des paramètres de configuration suivants : un plan de fréquence, et/ou des positionnements temporels des émissions, des diagrammes et/ou orientations d'antenne, des schémas d'accès radio et des schémas de modulation/codage des signaux émis et reçus, le ou les paramètres étant adaptés à minimiser ou éliminer les effets fratricides sur les N plateformes amis de réception,
• utiliser lesdits paramètres de configuration en émission et/ou réception pour les M plateformes d'émission amies et les N plateformes de réception amies.

The invention relates to a method for minimizing in an adaptive and decentralized manner the fratricidal effects induced by the jamming of P zones ZB or predefined positions in a communications network comprising friendly transmitters, jammers and friendly receivers, said network comprising N_pl platforms, a number M ≤ N_pl of said platforms, called friendly transmission platforms being equipped with antennas and systems for transmitting useful transmission signals that can be configured dynamically, a number N ≤ N_pl of said platforms, also called friendly platforms, being equipped with '' antennas and dynamically configurable reception systems for useful transmission signals, a number J ≤ N_pl of said platforms being equipped with scrambling systems and antennas having known characteristics of the friendly transmission and reception platforms, said scrambling systems and antennas being adapted to prevent transmissions between entities external to said network of friendly platforms, said platforms constituting a network, characterized in that it comprises at least the following steps:

• E ₀ : Establish a local reception situation: at each of the N friendly reception platforms measure, E ₁ , the communication signals Su friends received by said platforms from the M friendly transmitters, from said measurements, for each of the N friendly reception platforms, estimate, E ₂ , the M useful levels received and the M useful propagation channels, N * M estimated,
• E ₃ : Establish a local interference situation: at each of the N friendly reception platforms measure, E ₄ , the interference signals received by said friendly reception platforms from the J jammers, from measurements of the interference signals , for each of the N friendly reception platforms, estimate, E ₅ , the J fratricidal interference levels received and the J fratricidal interference channels, N * J estimated in all,
• knowing a priori the waveforms of the jamming signals and the associated settings, from the states of the local jamming situation established by each of the N receiving platforms on the J signals coming from the J jammers, from the local situation of reception established by each of the N receiving platforms on the useful communication signals Su, determine for each of the M friendly transmitting platforms and for each of the N friendly receiving platforms, at least one of the following configuration parameters: a frequency plan, and / or temporal positioning of transmissions, antenna diagrams and / or orientations, radio access diagrams and modulation / coding diagrams of transmitted and received signals, the parameter (s) being adapted to minimize or eliminate fratricidal effects on N friendly reception platforms,
• using said configuration parameters in transmission and / or reception for the M friendly transmission platforms and the N friendly reception platforms.

After having defined a first set of configuration parameters of the M friendly platforms and of the N friendly platforms, the method will reiterate the steps E ₀ to E ₅ over time in order to maintain and optimize the configuration parameters of the platforms.

The method uses, for example, the measurement of the propagation channels coming from the J scrambling platforms, to recognize in situ a predefined and known scrambling strategy in order to jointly optimize the transmission and the quality of the useful transmissions at the level of the platforms. friendly transmitters by adapting the transmission power levels and / or the frequency plans and / or the temporal positioning of the transmissions and / or the spatio-temporal coding schemes and / or the protocols for accessing the radioelectric resource used by friendly transmitters and receivers.

The method can use scrambling signals which encode, in a manner known to friendly receivers, information useful to friendly transmitters and receivers in order to inform the latter of the scrambling strategy employed, the characteristics of the interference waveforms and associated parameters, transmission power, type of diagram and orientation of the antennas, position, altitude, to facilitate the joint optimization of the transmissions and reception processing of useful transmissions at the level of the friendly transmitting and receiving platforms, said coded information being reconstituted by the analysis of the jamming signals received by the friendly receivers or decoded in the jamming signals received by the friendly receivers.

According to an alternative embodiment, the method uses, for example, transmitters and programmable friendly receivers adapted to dynamically take into account transmission instructions, on the power and / or on temporal parameters, the waveform, the spatio-temporal coding, the amplitude phase weighting of the antenna elements.

The method can be used in transmission networks using MIMO, MISO, SIMO or SISO protocols with or without a return path from friendly receivers to friendly transmitters.

The method can also be used in a radio network comprising receivers adapted to measure the values of transmission channels on the useful transmitters and on the jammers.

According to another variant, the method can be used in a radio network comprising one or more reception stations comprising antenna elements coupled to an interceptor adapted to carry out transmission channel measurements on the useful transmitters and on the jammers.

The process is decentralized and specific to each sender friend receiver friend link. In particular, it makes use of the environmental measurement capacities at work in modern modems (SISO, MISO, SIMO and MIMO as appropriate). It also exploits the knowledge, a priori by the friendly transceiver stations, of the interference frequency plans, patterns and waveforms, which makes them easily recognizable by the friendly stations with a minimum analysis, carried out at the same time as the CIR measurements and informed equalization procedures specific to modern modems. In addition, the frequency plans, temporal patterns and coding modulation schemes specific to friendly links can also be predefined in advance with a reduced set of parameters, and adapted to the radio situation over time, depending on the situation. Frequency channel occupancy, time patterns and interference waveforms. The analysis needs in the friendly transmitters / receivers are then reduced and the decision making on the adaptation of the friendly communication signals is then simplified.

• La figure 1, un exemple d'architecture du système selon l'invention,
• La figure 2, un exemple formel de modèle de canal de propagation généralisé au cas MIMO, avec définitions et notations des grandeurs géométriques et physiques afférentes,
• Les figures 3A, 3B, une illustration des notions de graphe et de macrographe réseau, utilisées pour décrire les liens entre postes amis (Tx, Rx), les interactions entre brouilleurs Br et entités externes à brouiller,
• La figure 4, un produit logique entre graphe réseau et matrice canal, définissant une matrice de canal généralisée qui tient compte à la fois des liens ou interactions entre les acteurs, émetteurs récepteurs, brouilleurs, zones ou points à brouiller, et des canaux de propagation entre ces acteurs.

Other characteristics and advantages of the present invention will appear more clearly on reading the description given by way of illustration and in no way limiting appended to the figures which represent:

• The figure 1 , an example of the architecture of the system according to the invention,
• The figure 2 , a formal example of a propagation channel model generalized to the MIMO case, with definitions and notations of the related geometrical and physical quantities,
• The figures 3A , 3B , an illustration of the notions of graph and network macrograph, used to describe the links between friendly stations (Tx, Rx), the interactions between jammers Br and external entities to be jammed,
• The figure 4 , a logical product between network graph and channel matrix, defining a generalized channel matrix which takes into account both the links or interactions between the players, transceivers, jammers, areas or points to be jammed, and the propagation channels between these players .

The example which follows is given by way of illustration and in no way limiting for a communication system comprising N_pl transmission platforms which have MIMO, MISO, SIMO or SISO communication stations.

The figure 1 shows schematically an example of network architecture in which the method according to the invention can be implemented.

One or more receiving stations Rx ₁ , Rx ₂ , ..., Rx _N are on a point-to-point or point-to-multipoint link by wireless communication, for example with M = N_pl - 1 ≤ N_pl platforms or friendly transmitter / receiver stations 10, that is to say stations equipped with a transmitting part Tx and a receiving part Rx. The M friendly platforms are equipped with antennas 10e and dynamically configurable systems 11 for transmitting useful transmission signals.

The network comprises a number N ≤ N_pl of said platforms, also called friendly platforms, being equipped with antennas 12r and systems 13 dynamically configurable reception of useful transmission signals.

Among these N_pl platforms, a number J ≤ N_pl “jammer” platforms B _r1 , ... B _rJ have system 14 and a jamming antenna 15b, of the omnidirectional type, of the directive type or of the network type. The emission characteristics of the systems and antennas are known to the friendly platforms. The transmission characteristics are chosen in particular to prevent transmissions between entities external to said network of friendly platforms, said platforms constituting an inter-platform network.

The friendly platforms (jammers or without jammer) therefore define an inter-platform communications network which appears, if we consider all the antenna elements, as a macro-network. On the figure 1 a zone ZB to be scrambled has also been shown in which radio equipment external to the network of friendly stations can be found. Each receiving station Rx ₁ to Rx _N receives M transmitting stations T _x1 ... T _xM , friendly useful communication signals. A station performs received signal level Nsr and channel impulse response measurements. Each station also receives jammers B _r1, ... B _rJ , jamming signals Sb about which it is informed (i.e. it knows a priori the main characteristics) and can also carry out level measurements received jamming signal Nbr and channel impulse responses.

Each station is equipped with a device adapted to manage, at any time, the communication links with the other stations, the device being for example a decision-making body 20 and decentralized local control specific to each friend transmitter / receiver link.

The decision-making bodies correspond, for example, to the MAC access layer of a terminal or of a master station. A station comprises a processing device receiving information on the friend signal, scrambling signal, the values of the associated channels and which is adapted to deduce therefrom the values of the transmission / reception parameters which make it possible not to disturb the links between friends.

1. I : lien commun classique incluant l'ensemble des mesures effectuées sur les liens de communications ou en anglo-saxon « reporting » (mesures effectués par les postes amis ou par des intercepteurs amis au profit des postes amis sur les séquences de signaux émis par les émetteurs amis Tx,) retransmis le cas échéant par voie retour vers les postes Tx amis,
2. II : lien comprenant le compte-rendu ou « reporting » des mesures sur signal brouilleur, i .e. l'ensemble des mesures effectuées sur les signaux brouilleurs (mesures effectués par les récepteurs amis ou par des intercepteurs au profit des postes récepteurs amis sur les séquences de signaux émis par les brouilleurs Br, informations retransmises le cas échéant par voie retour vers les postes Tx amis),
3. III : lien de commande des brouilleurs à partir des informations collectées par les récepteurs ou intercepteurs sur la plate forme du brouilleur (ou en liaison avec celle-ci) et de l'organe de décision local propres aux liens Tx amis Rx amis, et
4. IV : émission des signaux de brouillage vers la zone visée ZB et/ou vers les entités externes Ci au réseau amis.

Communication links are shown on the figure 1 as follows :

1. I: classic common link including all the measurements made on the communications links or in Anglo-Saxon “reporting” (measurements made by friendly stations or by friendly interceptors for the benefit of friendly stations on the signal sequences emitted by the Tx friendly transmitters,) retransmitted if necessary by return channel to friendly Tx sets,
2. II: link including the report or "reporting" of measurements on interfering signal, i .e. all the measurements carried out on the interfering signals (measurements carried out by friendly receivers or by interceptors for the benefit of friendly receiving stations on the signal sequences emitted by the Br jammers, information retransmitted if necessary by return channel to the Tx stations friends),
3. III: jammer control link from information collected by receivers or interceptors on the jammer platform (or in conjunction with it) and from the local decision-making body specific to Tx friends Rx friendly links, and
4. IV: transmission of jamming signals to the targeted zone ZB and / or to entities Ci external to the friendly network.

• les enregistrements/mesures des signaux de communication reçus par des intercepteurs, modules d'analyses et fonction d'appréhension de l'environnement (ou « sensing » en anglais) dédiés qui sont par exemple co-localisés ou intégrés avec au moins l'un des postes amis,
• les enregistrements/mesures des signaux de brouillage interférant avec les postes amis, par des intercepteurs, modules d'analyses et fonction de sensing dédiés qui sont par exemple co-localisés ou intégrés avec au moins l'un des postes amis,
• une description formelle des interactions entre postes émetteurs amis Tx, postes récepteurs amis Rx, brouilleurs Br et entités externes à brouiller Ci, par des graphes et macro-graphes qui seront précisés dans la suite,
• sur un modèle général de propagation du canal de transmission, généralisé à la prise en compte des interactions effectives entre postes émetteurs et récepteurs amis (Tx Rx) (généralement intégrés ensemble au sein d'un poste de transmission ami), brouilleurs Br et entités externes Ci, au travers d'une notion de matrice canal généralisée précisée dans la suite,
• sur la mise en forme puis sur la résolution partielle d'un problème d'optimisation sous contraintes, précisé dans la suite,
• des brouilleurs programmables et dynamiquement configurables en terme de forme d'onde (enveloppe, modulation, amplitude, phase, etc.), pour lesquels sont connus les plans de fréquence (choix des bandes sous bandes et porteuses du signal de brouillage), les motifs temporels d'émission (récurrence des émissions selon le temps et la fréquence),
• de formes d'onde de brouillage, qui sont multiples et le cas échéant complexes, mais connues des récepteurs amis,
• des séquences de signaux numériques Sb émis par les brouilleurs, choisis et adaptés pour permettre des mesures précises en réception sur lesdits signaux de brouillages reçus par les postes ou stations du réseau,
• des séquences de signaux numériques Su émis par les émetteurs amis, choisis pour permettre des mesures précises en réception sur lesdits signaux amis reçus pas les postes ou stations du réseau,
• une élaboration de la situation de brouillage locale au niveau d'un poste, d'après les mesures de puissance de brouillage reçues sur les postes et des canaux de transmission associés ; l'élaboration est effectuée par les postes amis, aidée par la connaissance a priori par les récepteurs amis des plans de fréquence, motifs temporels et formes d'ondes de brouillage possibles,
• une élaboration de la situation de réception locale au niveau d'une station, d'après les mesures précises de puissance utile reçue provenant des émetteurs amis et des canaux de transmission associées ; l'élaboration est effectuée par les postes amis, aidée par la connaissance a priori par les récepteurs amis des plans de fréquence, motifs temporels et formes d'ondes amies possibles,
• de plans de fréquence, motifs et récurrences d'émission, schémas de codage et de modulation spatio-temporels paramétrables des signaux numériques émis par les émetteurs amis, choisis et destinés à leur permettre d'adapter dynamiquement les liens de transmission à la situation de brouillage, à la fois par traitement d'antenne (conformations et orientations optimales des diagrammes d'antenne en émission et en réception) et par traitement temps fréquence (égalisation, modulation et codages et débits adaptatifs, etc.),
• des organes de décisions décentralisés, voire internes aux postes amis, permettant l'élaboration de consignes et des paramétrages adaptatifs en émission réception qui optimisent les liens entre postes amis, lesdites décisions étant basées sur l'élaboration des situations de brouillage locales et sur l'élaboration des situations de réception locales précitées.

The method implemented by the invention is based in particular on:

• the records / measurements of communication signals received by dedicated interceptors, analysis modules and environmental sensing function which are for example co-located or integrated with at least one friendly posts,
• recordings / measurements of jamming signals interfering with friendly stations, by dedicated interceptors, analysis modules and sensing function which are for example co-located or integrated with at least one of the friendly stations,
• a formal description of the interactions between friendly transmitting stations Tx, friendly receiving stations Rx, jammers Br and external entities to be scrambled Ci, by graphs and macro-graphs which will be specified in the following,
• on a general propagation model of the transmission channel, generalized to take into account the effective interactions between friendly transmitting and receiving stations (Tx Rx) (generally integrated together within a friendly transmission station), Br jammers and external entities Ci, through a notion of generalized channel matrix specified below,
• on the formatting then on the partial resolution of an optimization problem under constraints, specified in the continuation,
• programmable and dynamically configurable jammers in terms of waveform (envelope, modulation, amplitude, phase, etc.), for which the frequency plans are known (choice of bands under bands and carriers of the jamming signal), the patterns emission times (recurrence of emissions according to time and frequency),
• jamming waveforms, which are multiple and possibly complex, but known to friendly receivers,
• sequences of digital signals Sb emitted by the jammers, chosen and adapted to allow precise measurements in reception on said interference signals received by the stations or stations of the network,
• sequences of digital signals Su emitted by friendly transmitters, chosen to allow precise measurements in reception on said friendly signals received by stations or stations of the network,
• developing the local interference situation at a station, based on the interference power measurements received at the stations and associated transmission channels; the elaboration is carried out by the friendly stations, helped by the a priori knowledge by the friendly receivers of the frequency planes, temporal patterns and shapes possible interference waves,
• an elaboration of the local reception situation at a station, based on the precise measurements of useful power received from the friendly transmitters and the associated transmission channels; the elaboration is carried out by the friendly stations, aided by the a priori knowledge by the friendly receivers of the frequency plans, temporal patterns and possible friendly waveforms,
• frequency plans, transmission patterns and recurrences, configurable spatio-temporal coding and modulation schemes of the digital signals transmitted by friendly transmitters, chosen and intended to allow them to dynamically adapt the transmission links to the jamming situation , both by antenna processing (optimal conformations and orientations of the antenna patterns in transmission and reception) and by time-frequency processing (equalization, modulation and adaptive codings and rates, etc.),
• decentralized decision-making bodies, or even internal to friendly stations, allowing the development of instructions and adaptive settings in transmission reception which optimize the links between friendly stations, said decisions being based on the development of local jamming situations and on the development of the aforementioned local reception situations.

In the remainder of the description, the channels are determined as being made up of all the radio propagations between each of the transmitters (jammer or friend communication transmitter) and each of the friend communication receivers or each of the targets or areas to be jammed Ci ( the areas to be scrambled being discretized in the form of lists of points to be scrambled).

The channel matrix is the matrix of combinations of microwave propagation channels between transmitters and receivers (Tx Rx channel matrix), between jammers and receivers (Br Rx channel matrix) or between jammers and each of the points to scramble (Br channel matrix, This). These matrices are considered in a first global approach between the platforms (and not between the antenna elements present on each platform) and the value a _{m, n} of an element of the channel matrix therefore physically and globally describes the Hertzian channel between platform m and platform n. In the event that a friend receiver comes into play, the matrix is filled in from the measurements made on the useful signals and on the interfering signals. In the case where an area or a point to be scrambled C _i comes into play, the matrix is informed from a propagation model between a scrambler Br and the target Ci. All these matrices are then considered in a second approach between each transmitting antenna element (each platform can be equipped with several transmitting antennas, for example scrambling antenna and transmission antenna, themselves made up of arrays of antenna elements) and each receiving antenna element (each platform can be equipped with several receiving antennas, themselves made up of networks of antenna elements). For each of the approaches, the first level of description of this matrix is binary a _{m, n} = 1 if the platform (respectively the antenna) n, receives a signal from the platform (respectively the antenna) m, a finer level in the second approach in particular, corresponds to consider a _{m, n} as the impulse response of the channel m, n, (if applicable matrix) which completely characterizes a multiple linear channel multiple input output or MIMO, multiple input single output or MISO , single input multiple output or SIMO, or single input single output or SISO. This impulse response can be estimated from measurements made by friendly Rx receivers on the signal sequences and jammers, by propagation models considered between transmitters or jammers and receivers, and from the propagation models considered between jammers or jammers. transmitters and target or area to be interfered with.

Knowledge of station positions is useful for optimizing the operation of the communication network and is used to optimization of interference. A synchronism or precise dating of the measurements is also useful for better overall optimization.

The precise knowledge of the signal sequences contained in the scrambling signals Sb and in the useful communication signals Su is used for the measurement of the signal reception levels and the measurement of the corresponding propagation channels by the friendly Rx receivers, and contributes to the overall optimization of the process.

Graphical representations have the advantage of offering a synthetic representation of all the interactions between the actors. For example, it is possible to represent platforms or antennas by placing an arc between two platforms or antennas if the signal emitted by one is received by the other, and therefore if the channel could be measured.

Example given for the implementation of the method according to the invention

MIMO, MISO, SIMO, SISO “useful” communication stations are available on platforms in number N_PI, of which J platforms include jammers.

"Networks of transmitters and receivers for useful transmissions "

We therefore have N_pl communication platforms. Each of these platforms is MIMO, MISO, SIMO or SISO. We denote by M ₁ , M ₂ ..., M _{N_pl} , the number of antenna elements in transmission of each of these platforms. N ₁ , N ₂ ..., N _{N_pl} , denote the number of antenna elements receiving each of these N platforms.

The network made up of Σ _{M_pl} = Σ _{m = 1} ... _{N_pl} M _m transmitter antenna elements Tx or Br and Σ _{N_pl} = Σ _{n = 1} ... _{N_pl} N _n antenna elements Rx appears as a macro-network, a priori strongly incomplete. The set of communication platforms constitutes a network represented by the network graph of size N_pl as defined above and denoted by G ₀ . When we consider all the antenna elements, we prefer a representation by the macro-graph of size Σ _{M_pl} + Σ _{N_pl} as defined above and noted G ₀ '.

The channel matrix of this macro network made up of N_pl platforms and Σ _{M_pl + N_pl} antenna elements can be formally written, as it will be explained below or as one can see it on the figures 3A , 3B , 4 , for which a generic notation is used, in the generalized form H ₀ '(Tx, Rx) = G ₀ ' ∝ [H ₀ ^(A) (Tx, Rx), H ₀ ^(R) (Rx, Tx)]. It is determined by the topology of the network (which determines G ₀ and G ₀ ') and the channel matrices H ₀ ^(A) and H ₀ ^(R) specific to each link Tx _m → Rx _n ..

In the method implemented, called “open loop” according to the invention, the transmitters, receivers and communication nodes of the friend network manage at each instant t (sampling t _k , k = 1, 2, ...), the communication links and the related settings (protocols, bit rates, coding and modulation schemes, where applicable, the weighting of the antenna networks in transmission / reception, use of relays, etc.), adapting to the radio environment and possible interference residues, by being explicitly managed by a local, decentralized decision-making and control body specific to each friendly Tx-Rx link. The interference signals and levels themselves are not controlled from friendly transmitters or receivers, but set according to independent efficiency criteria specific to the geometry and the targets to be interfered with. The radio situation and the level of interference due to jamming are measured by the friendly receiver on each link. The frequency plan, spatio-temporal and temporal radio access configuration, modulation and coding schemes, and reception processing in friendly stations are defined by decentralized local control at each station to optimize the link useful and to minimize the residual fratricidal effects associated with interference, by making use of the available techniques known to those skilled in the art on friendly stations, where appropriate, for example: transposition of useful communications to empty carriers and / or little scrambled in the frequency plan, "temporal positioning" or "slottage" in English of the communication on time intervals little scrambled or left empty by forms of jamming themselves "slotted" or impulsive), anti-jamming pathway formation, interference reduction techniques and joint separation and demodulation techniques for friendly receivers having antenna arrays and / or using orthogonal encodings in the wanted signals transmitted, reduction of bit rate and / or increase in signaling power correction of the encodings used (at the cost of spectral efficiency, of the complexity of the reception processing, of the consumption if necessary), etc.

où

• N est le nombre exact de plates formes réceptrices comportant une antenne de réception (N ≤ N_pl),
• M est le nombre exact de plates formes émettrices comportant une antenne d'émission destinée aux transmissions de signaux utiles (M ≤ N_pl),
• H₀' est la matrice généralisée de canal « émetteurs vers récepteurs»,
• X_n(t) n 1,..., N est le vecteur des signaux utiles reçus sur le réseau des éléments d'antennes de la plate-forme réceptrice d'indice n, ,
• S_m(t) n = 1,...,M est le vecteur des signaux émis sur le réseau des éléments d'antennes de la plate-forme émettrice d'indice m, de bande B,

The set of antenna networks of transmitters Tx ₁ , ..., Tx _M (M ≤ N_pl) and receivers Rx ₁ , ..., Rx _N (N ≤ N_pl) is therefore formalized as a macro-network G ₀ ' (defined by a size matrix (Σ _{M_pl} + Σ _{N_pl} ) ² ) whose links are completely described as on figure 4 by a generalized channel matrix which determines the complete generalized channel H ₀ '(Tx, Rx, τ). These matrices are determined by the topology of the network macro graph G 'by the channel matrices specific to each link Tx _m → Rx _n The formal construction of these matrices is given in figure 4 , examples of figures 3A and 3B , and some figure 2 illustrate the taking into account of the propagation channel to construct the channel matrices specific to each link Tx _m → Rx _n For the path Tx _m -> Rx _n , the formal expression of the useful signals coming from the transmitting platforms received at the level of receiving platforms is then at each instant t: $$\mathrm{X}\left(\mathrm{t}\right)=\left({\mathrm{<figure-callout\; id="0"\; label="H"\; filenames="imgf0003.png,imgf0004.png"\; state="\{\{state\}\}">H</figure-callout>}}_0\prime \ast \mathrm{S}\right)\left(\mathrm{t}\right)\mathrm{i}.\mathrm{e}.\left[\begin{array}{c}{\mathrm{X}}_1\left(\mathrm{t}\right)\\ {\mathrm{X}}_{\mathrm{NOT}}\left(\mathrm{t}\right)\end{array}\right]=\left[\left(\begin{array}{cc}{\mathrm{<figure-callout\; id="0"\; label="H"\; filenames="imgf0003.png,imgf0004.png"\; state="\{\{state\}\}">H</figure-callout>}}_{0\prime 11}& {\mathrm{<figure-callout\; id="0"\; label="H"\; filenames="imgf0003.png,imgf0004.png"\; state="\{\{state\}\}">H</figure-callout>}}_{0\prime 1\mathrm{<figure-callout\; id="0"\; label="M\; H"\; filenames="imgf0003.png,imgf0004.png"\; state="\{\{state\}\}">M</figure-callout>}}& \\ {\mathrm{H}}_{}{\mathrm{}}_{0\prime \mathrm{NOT}1}& {\mathrm{<figure-callout\; id="0"\; label="H"\; filenames="imgf0003.png,imgf0004.png"\; state="\{\{state\}\}">H</figure-callout>}}_{0\prime \mathrm{NM}}\end{array}\right)\ast \left(\begin{array}{c}{\mathrm{S}}_1\\ {\mathrm{S}}_{\mathrm{M}}\end{array}\right)\right]\left(\mathrm{t}\right)$$

or

• N is the exact number of receiving platforms including a receiving antenna (N ≤ N_pl),
• M is the exact number of transmitting platforms including a transmitting antenna intended for the transmission of useful signals (M ≤ N_pl),
• H ₀ 'is the generalized matrix of the channel "transmitters to receivers",
• X _n (t) n 1, ..., N is the vector of useful signals received on the array of antenna elements of the receiving platform of index n,,
• S _m (t) n = 1, ..., M is the vector of signals transmitted over the array of antenna elements of the transmitting platform of index m, of band B,

On the figure 2 is also shown an example of the geometry of the propagation in an axis X (East), Y (North).

• S_m(t) précité,
• X_nm(t), le vecteur contribution du signal Sm reçu sur l'élément n du réseau antennaire en réception,
• X_n(t) précité, vecteur signal total reçu sur le capteur n du réseau,
• L_mn le nombre de trajets du canal de propagation,
• I l'indice du I-ième multi-trajet,
• α(^m,n)I l'atténuation du trajet I par rapport aux pertes moyennes,
• γ^(m,n)I, la direction d'arrivée moyenne du trajet I,
• τ^(m,n)I, le retard moyen du trajet L, les retards sont contenus dans un intervalle [O, T^(m,n)] dépendant du canal urbain, montagneux, etc.
• N^(m,n), est le nombre de sous-trajets associés au trajet I supposés indiscernables pour le signal de bande B donc répartis dans un intervalle de durée T^(m,n)<<1/B
• n_i est l'indice du sous-trajet I,
• ϕ^(m,n) _ni,i est la phase du sous-trajet d'indices I et n_i,
• α^(m,n) _ni,i est le niveau relatif du sous trajet d'indices I et n_i
• θ^(m,n) _ni,i est la direction d'arrivée du sous-trajet d'indices I et n_i
• U_s(θ^(m,n) _ni,i) est le vecteur directionnel correspondant au sous trajet d'indices I et n_i pour la source de signal s.

The link between the element of index m of the network of transmitting platforms and the element of index n of the network of receiving platforms is characterized by:

• S _m (t) above,
• X _nm (t), the contribution vector of the signal Sm received on the element n of the antenna array in reception,
• X _n (t) above, total signal vector received on the sensor n of the network,
• L _mn the number of paths of the propagation channel,
• I the index of the I-th multi-path,
• α ( ^{m, n)} I the attenuation of the path I compared to the average losses,
• γ ^{(m, n)} I, the average direction of arrival of path I,
• τ ^{(m, n)} I, the average delay of the path L, the delays are contained in an interval [O, T ^{(m, n)} ] depending on the urban channel, mountainous, etc.
• N ^{(m, n)} , is the number of sub-paths associated with path I assumed to be indistinguishable for the band signal B therefore distributed in an interval of duration T ^{(m, n)} << 1 / B
• n _i is the index of the sub-path I,
• ϕ ^{(m, n)} _{ni, i} is the phase of the sub-path with indices I and n _i ,
• α ^{(m, n)} _{ni, i} is the relative level of the sub-path of indices I and n _i
• θ ^{(m, n)} _{ni, i} is the direction of arrival of the sub-path with indices I and n _i
• U _s (θ ^{(m, n)} _{ni, i} ) is the directional vector corresponding to the subpath of indices I and n _i for the signal source s.

The temporal distribution of the paths determines its type of fading (flat or selective depending on whether T ^{(m, n)} ≤ ≥ 1 / B) and its temporal coherence. The temporal distribution of the sub-paths determines its type of fading (flat or selective. depending on whether T ^{(m, n)} _i ≤ ≥ 1 / B) and its temporal coherence. The amplitude distribution of the paths (respectively sub-paths) determines its statistical type (Rayleigh or Rice).

The angular distribution of the paths (respectively sub-paths) determines its angular coherence (omni-directional diffusion, diffusion cone).

"Parameters and powers of the useful signals according to the reception processing":

Data _m represents the useful signal to be transmitted from the transmitter Tx _m to the receiver Rx _n . S _m represents the signal or a vector signal at the output of the transmitter friend Tx _m , by the linear transformation S _m = Coding _m. Data _m which generally models a spatio-temporal coding scheme in transmission as used in SISO, SIMO, MISO or MIMO transmissions, the Coding operator _m representing the space-time coding applied by the transmitter Tx _m to the payload signal Data _m at the input of said transmitter. The set of possible values for the coding schemes, Coding _m , is denoted Dom_Codage.

In all cases, the space-time operator Coding _m can be defined in a vector space of linear operators operating from a finite-dimensional vector space (the space of sampled useful signals of finite spatial dimension taken over a finite time horizon and) in a finite-dimensional image vector space (the space of spatiotemporally coded sampled signals, also of finite spatial dimension and finite time horizon), and Dom_Codage can be taken as the unit sphere of said vector space.

The power of the signal S _m is denoted π _Sm .

It is possible to express π _Sm in the form π _Sm = .S _m ^H .S _m,.

X _{m, n} = H ₀ ' _{m, n} . S _m represents the signal or the vector signal input from a friend receiver Rx _n after propagation in the filter H _{m, n} .

The power of the signal X _mn is denoted π _Xmn.

It is possible to express π _Xmn in the form π _Xmn = X _mn ^H. X _mn .

T _n represents the set of processing and filtering applied to the input signal X _n to produce the processing output signal formally represented by Y _mn = T _n (X _{m, n} ); T _n generally models a spatio-temporal reception decoding scheme as used in SISO, SIMO, MISO or MIMO transmissions.

The set of possible values for the processing in reception T _n is denoted Dom_T.

In all cases, the spatio-temporal operator T _n can be defined in a vector space of linear operators operating from a finite-dimensional vector space (the space of signals sampled at the reception antenna input taken over a horizon time) with value in an image vector space of finite dimension (the space of sampled signals decoded spatio-temporally), and Dom_T can be taken as the unit sphere of said vector space.

The power of the signal Y _mn is noted π _Ymn

If T _n is purely linear, it is possible to express π _Ymn as a function of the coding Coding _m applied, as a function of the channel H ₀ ' _{m, n} , and as a function of the processing applied in reception T _n in the form $$\begin{array}{l}{\mathrm{\pi }}_{\mathrm{Ymn}}\left({\mathrm{<figure-callout\; id="0"\; label="Coding\; m\; H"\; filenames="imgf0003.png,imgf0004.png"\; state="\{\{state\}\}">Coding</figure-callout>}}_{\mathrm{m}},{\mathrm{H}}_{},{\mathrm{}}_{0\prime \mathrm{m},\mathrm{not}},{\mathrm{T}}_{\mathrm{not}}\right)={{\mathrm{Y}}_{\mathrm{mn}}}^{\mathrm{H}}.{\mathrm{Y}}_{\mathrm{mn}}\\ ={\left({\mathrm{T}}_{\mathrm{not}}.{\mathrm{<figure-callout\; id="0"\; label="H"\; filenames="imgf0003.png,imgf0004.png"\; state="\{\{state\}\}">H</figure-callout>}}_{0\prime \mathrm{m},\mathrm{not}}.{\mathrm{Coding}}_{\mathrm{m}}.{\mathrm{Data}}_{\mathrm{m}}\right)}^{\mathrm{H}}.{\mathrm{T}}_{\mathrm{not}}.{\mathrm{<figure-callout\; id="0"\; label="H"\; filenames="imgf0003.png,imgf0004.png"\; state="\{\{state\}\}">H</figure-callout>}}_{0\prime \mathrm{m},\mathrm{not}}.{\mathrm{Coding}}_{\mathrm{m}}.{\mathrm{Data}}_{\mathrm{m}}\\ ={{\mathrm{X}}_{\mathrm{mn}}}^{\mathrm{H}}.{{\mathrm{T}}_{\mathrm{not}}}^{\mathrm{H}}.{\mathrm{T}}_{\mathrm{not}}.{\mathrm{X}}_{\mathrm{mn}}.\\ ={{\mathrm{Data}}_{\mathrm{m}}}^{\mathrm{H}}.{{\mathrm{Coding}}_{\mathrm{m}}}^{\mathrm{H}}.{\mathrm{<figure-callout\; id="0"\; label="H"\; filenames="imgf0003.png,imgf0004.png"\; state="\{\{state\}\}">H</figure-callout>}}_{0\prime \mathrm{m},\mathrm{not}}.{{\mathrm{T}}_{\mathrm{not}}}^{\mathrm{H}}.{\mathrm{T}}_{\mathrm{not}}.{\mathrm{<figure-callout\; id="0"\; label="H"\; filenames="imgf0003.png,imgf0004.png"\; state="\{\{state\}\}">H</figure-callout>}}_{0\prime \mathrm{m},\mathrm{not}}.{\mathrm{Coding}}_{\mathrm{m}}.{\mathrm{Data}}_{\mathrm{m}}\end{array}$$

In this expression, only data transmitted Data _m and the channel H ₀ ' _{m, n} escape the control of the local control organ, which can on the other hand control Framing _n , and T _n in the domains of the possible values Dom_Codage and Dom_T to optimize the useful link Tx _m Rx _n .

At each of the N friendly reception platforms, the method will establish, E ₀ , a local reception situation by measuring, E ₁ , the communication signals Su friends received by said platforms from the M friendly transmitters then, from of said measures, estimating, E ₂ , for each of the N friendly reception platforms the M received useful levels and the M useful propagation channels (N * M estimated in all).

The useful signals and the procedures for measuring and equalizing these signals in the receivers, in particular on synchronization sequences or on pilot sequences, make it possible to estimate the MxN useful communication channels.

"Network of jammers and receivers"

J platforms among the N_pl are equipped with "jammers" adapted to jam the communications of elements external to the friendly network, they are noted Br ₁ , ..., Br _J. The set of jammers Br ₁ , ..., Br _J and receivers and Rx ₁ , ..., Rx _N constitutes a “jamming” network represented by an interference graph denoted GJ and subjected to a propagation channel generalized HJ '= GJ'& H _J (Br, Rx) defined according to the process described in figure 4 , by considering the number of transmitting platforms J, the number of receiving platforms N and the J x N matrices of associated elementary channels.

• une consigne de niveau de puissance C_PIRE_j,
• une forme d'onde de brouillage B_j, connue et mesurée in situ par les récepteurs amis
• une ou plusieurs durées de brouillage Tb_j avec les récurrences Rbi et une avance ou un retard τ_j en émission du signal B_j par rapport à une horloge commune, ces caractéristiques étant connues apriori et/ou reconnaissables in situ par les récepteurs amis lors de leurs processus de mesure,
• un ou plusieurs intervalles de fréquence notés Fb_j de brouillage correspondant aux intervalles de brouillage, connus a priori et/ou reconnaissables in situ par les récepteurs amis lors de leurs processus de mesure,
• des pondérations en amplitude A_j et en phase ϕ_j,
• le cas échéant une orientation d'antenne Ψ_j qui peut être assimilée dans la suite comme une pondération spatiale induite par la directivité d'antenne.

Each of the jammers Br _j , of index j, has an equivalent power level radiated in transmission (EIRP) defined by an interval [0, PIREMAX _j ], fixed, and known to friendly receivers for the implementation of l invention, with:

• a power level setpoint C_PIRE _j ,
• a jamming waveform B _j , known and measured in situ by friendly receivers
• one or more jamming durations Tb _j with recurrences Rbi and an advance or delay τ _j in transmission of the signal B _j with respect to a common clock, these characteristics being known a priori and / or recognizable in situ by friendly receivers when their measurement processes,
• one or more frequency intervals denoted Fb _j of interference corresponding to the interference intervals, known a priori and / or recognizable in situ by friendly receivers during their measurement process,
• weightings in amplitude A _j and in phase ϕ _j ,
• where appropriate, an antenna orientation Ψ _j which can be assimilated in the following as a spatial weighting induced by the antenna directivity.

Advanced jammers can also be used in order to code or tag in their jamming waveform the power levels EIRP, the jamming waveforms, the durations of the jamming signals, the recurrences with which these jamming signals appear. , the delays, the frequencies, and the weightings A _i ϕ _i ψ _{i which} they apply to inform the friendly receivers.

• un macro-graphe « brouillage fratricide réseau » noté G_J' intégrant les émissions des seuls brouilleurs et la matrice de canal généralisée associée H_J' (figures 2, 3A, 3B).

According to the above, the set of antenna networks of the jammers Br ₁ , ..., Br _J and of the reception antenna networks of the receiving platforms Rx ₁ , ..., Rx _N is formalized by two interference macro-networks defined by:

• a "network fratricidal interference" macro-graph denoted G _J 'integrating the emissions of the jammers only and the associated generalized channel matrix H _J ' ( figures 2 , 3A , 3B ).

où

• N est le nombre exact de plates formes réceptrices comportant une antenne de réception (N ≤ N_pl),
• J est le nombre exact de plates formes comportant une antenne de brouillage (J≤ N_pl),
• H_J'⁽⁾ est la matrice généralisée de canal « brouilleurs vers récepteurs »,
• J_n(t) n = 1,...,N est le vecteur des signaux brouilleurs reçus sur le réseau des éléments d'antennes de la plate-forme réceptrice d'indice n,
• B_j(t) j = 1,...,J est le vecteur des signaux de brouillage émis sur le réseau des éléments d'antennes de la plate-forme d'indice j.

The formal expression J (t) of the interfering signals received on a receiving network is then the following at any time t: $$\mathrm{J}\left(\mathrm{t}\right)=\left({{\mathrm{H}}_{\mathrm{J}\prime }}^{\left(\mathrm{AT}\right)}\ast \mathrm{B}\right)\left(\mathrm{t}\right)\mathrm{i}.\mathrm{e}.\left[\begin{array}{c}{\mathrm{J}}_1\left(\mathrm{t}\right)\\ {\mathrm{J}}_{\mathrm{NOT}}\left(\mathrm{t}\right)\end{array}\right]=\left[\left(\begin{array}{cc}{\mathrm{H}}_{\mathrm{J}\prime 11}& {\mathrm{H}}_{\mathrm{J}\prime 1\mathrm{J}}\\ {\mathrm{H}}_{\mathrm{J}\prime \mathrm{NOT}1}& {\mathrm{H}}_{\mathrm{J}\prime \mathrm{NJ}}\end{array}\right)\ast \left(\begin{array}{c}{\mathrm{B}}_1\\ {\mathrm{B}}_{\mathrm{J}}\end{array}\right)\right]\left(\mathrm{t}\right)$$

or

• N is the exact number of receiving platforms including a receiving antenna (N ≤ N_pl),
• J is the exact number of platforms including a jamming antenna (J≤ N_pl),
• H _J ' ⁽⁾ is the generalized matrix of “jammers to receivers” channel,
• J _n (t) n = 1, ..., N is the vector of interfering signals received on the array of antenna elements of the receiving platform of index n,
• B _j (t) j = 1, ..., J is the vector of interference signals transmitted on the array of antenna elements of the platform of index j.

"Parameters and powers of interfering signals according to reception processing":

B _j represents the interfering signal at the jammer output Br _J.

J _jn = H _J ' _{j, n.} B _j represents the interfering signal for transmission from the interfering device Br _J to the receiver Rx _n

The power of the signal J _jn at the processing input is denoted π _Jjn

It is possible to express π _Jjn in the form π _Jjn = X _mn ^H. X _mn ..

After passing through the reception processing T _n specific to the receiver Tx _n , the scrambling signal at the input J _jn is transformed into a scrambling signal at the output J ' _jn = T _n (J _jn ).

The power of the signal is denoted π _J'jn . It is possible to express π _Ymn as a function of the treatment applied T _n in the form $$\begin{array}{l}{\mathrm{\pi }}_{\mathrm{J}\prime \mathrm{jn}}\left({\mathrm{T}}_{\mathrm{not}},{\mathrm{H}}_{\mathrm{J}\prime \mathrm{j},\mathrm{not}}\right)=\mathrm{J}{{\prime }_{\mathrm{jn}}}^{\mathrm{H}}.\mathrm{J}{\prime }_{\mathrm{jn}}.={\left({\mathrm{T}}_{\mathrm{not}}.{\mathrm{H}}_{\mathrm{J}\prime \mathrm{j},\mathrm{not}}.{\mathrm{B}}_{\mathrm{j}}\right)}^{\mathrm{H}}.\left({\mathrm{T}}_{\mathrm{not}}.{\mathrm{H}}_{\mathrm{J}\prime \mathrm{j},\mathrm{not}}.{\mathrm{B}}_{\mathrm{j}}\right)\\ ={{\mathrm{J}}_{\mathrm{jn}}}^{\mathrm{H}}.{{\mathrm{T}}_{\mathrm{not}}}^{\mathrm{H}}.{\mathrm{T}}_{\mathrm{not}}.{\mathrm{J}}_{\mathrm{jn}}.={{\mathrm{B}}_{\mathrm{j}}}^{\mathrm{H}}.{{\mathrm{H}}_{\mathrm{J}\prime \mathrm{j},\mathrm{not}}}^{\mathrm{H}}.{{\mathrm{T}}_{\mathrm{not}}}^{\mathrm{H}}.{\mathrm{T}}_{\mathrm{not}}.{\mathrm{H}}_{\mathrm{J}\prime \mathrm{j},\mathrm{not}}.{\mathrm{B}}_{\mathrm{j}})\end{array}$$

In this expression, the channel H _J ' _{j, n} and the scrambling signal transmitted B _j escape the control of the local control unit, which can on the other hand control T _n in the domain of possible values Dom_T to minimize the level of output jamming and optimize the useful link Tx _m Rx _n . The domain Dom_T of possible values for T _n depends on the nature of the spatio-temporal processing applied.

"Target zone or target receiver "

• dans le domaine temporel : la zone Ci peut correspondre à des slots temporels à brouiller indexés sur une trame pseudo-périodique connue et/ou contrôlée par la station maître des brouilleurs,
• dans le domaine fréquentiel : la zone Ci peut correspondre à des sous-bandes de brouillage à brouiller soit de manière continue, soit de manière périodique (avec indexation sur une trame pseudo-périodique) connue et/ou contrôlée par le ou les brouilleurs,
• dans le domaine spatial : la zone Ci peut correspondre à la position d'une cible identifiée, à une zone géographique autour de cette position, à une focalisation vers cette position. Ceci permet de considérer une matrice de canal H_BC des brouilleurs vers les zones cibles (qui se réduit dans le cas d'une seule zone de brouillage à un vecteur ligne 1xJ), dont les valeurs par défaut peuvent être déterminées en fonction d'un modèle géométrique ou d'un modèle empirique d'atténuation moyenne isotrope dépendant de la distance ou de tout autre modèle paramétrique ou empirique (la zone cible n'informe pas a priori les brouilleurs de l'efficacité du brouillage... le réseau de brouilleur ne peut donc initier sa stratégie de brouillage que d'après un modèle, et seulement ensuite contrôler le cas échéant l'efficacité du brouillage - avec une technique connue sous l'acronyme anglo-saxon look-through par exemple).

The J platforms Br ₁ ... Br _J are intended to scramble one or more targets or zones characterized by a list of positions Ci ₁ ... Ci _P to scramble. These positions are primarily geographical points, but can by extension be defined "in the broad sense" in the time / frequency / space domains:

• in the time domain: the area Ci can correspond to time slots to be scrambled indexed on a known pseudo-periodic frame and / or controlled by the master station of the scramblers,
• in the frequency domain: the area Ci may correspond to interference sub-bands to be scrambled either continuously or periodically (with indexing on a pseudo-periodic frame) known and / or controlled by the scrambler (s),
• in the spatial domain: the zone Ci can correspond to the position of an identified target, to a geographical zone around this position, to a focusing towards this position. This makes it possible to consider an H channel matrix _BC from the jammers to the target areas (which in the case of a single interference area is reduced to a 1xJ line vector), the default values of which can be determined as a function of a geometric model or an empirical distance-dependent isotropic average attenuation model or any other parametric or empirical model (the target area does not a priori inform the jammers about the effectiveness of the interference ... the jammer network It is therefore only possible to initiate its scrambling strategy according to a model, and only then to check if necessary the effectiveness of the scrambling - with a technique known by the Anglo-Saxon acronym look-through for example).

The jamming signal being fixed and generated, analysis or sensing modules in the friendly receivers or interceptors associated with them produce measurement results on the interfering signals by exploiting their a priori information of waveforms and model or scrambling “pattern” to accelerate and make their measurement procedure more reliable, so as to optimize their own links by adapting their spectral and temporal resource allocation plans and their modulation coding scheme. Decision-making is local and decentralized within level of each useful link, without retroactivity on the settings applied by the jammers, which leads to simplified management of the jammer network.

At each of the N friendly reception platforms, E ₃ , a local interference situation is established by measuring, E ₄ , the interference signals received by said friendly reception platforms from the J jammers, from the measurements of the signals interference, for each of the N friendly reception platforms, we estimate, E ₅ , the J fratricidal interference levels received and the J fratricidal interference channels, N * J estimated in all.

The scrambling signals also integrating known sequences, procedures for measuring and equalizing these signals apply in the same way to these signals in interceptors, analysis modules or sensing functions associated with friendly receivers.

The results of the measurements are used by the Rx receivers of the friendly stations, possibly communicated to the friendly Tx transmitters, if the links have return channels, to optimize the useful Tx friends / Rx links.

The jammer network and the settings which are applied to the jamming signals remain independent of the optimization instructions specific to the useful links.

Knowing, a priori, the waveforms of the jamming signals and the associated settings, from the states of local jamming situations established by each receiving platform on the J signals coming from the J jammers, from the state of situations reception local established by each receiving platform on the useful communication signals, the method calculates, for each of the M friendly transmitting platforms and each of the N friendly receiving platforms, frequency plans, temporal positions for the transmissions, diagrams and / or antenna orientations, radio access schemes and modulation / coding schemes for transmitted and received signals eliminating or all at least minimizing the fratricidal effects on the N friendly reception platforms, We then apply these first frequency plans, these temporal positions, these antenna diagrams and / or orientations, these radio access diagrams and these modulation / coding diagrams on the M friendly transmitting platforms and on the N friendly receiving platforms, in order to initiate the reduction of the fratricidal effects of interference.

According to one embodiment, the friendly receiving platforms continuously or recurrently pursue the evaluation of the local states of interference situation and of the local states of reception situations in order to continue the calculation of the frequency plans and the application of. these frequency plans, temporal positions of emissions, antenna diagrams and / or orientations, radio access diagrams and modulation / coding diagrams of the transmitted and received signals, so as to maintain and optimize, by iteration from frame to frame , the useful rate of the transmission service, the power and the quality of the transmissions and of the reception on the friendly platforms while maintaining or reducing the risk of acceptable fratricidal interference for the quality of the useful transmissions.

1. 1/ Le procédé selon l'invention peut être mis en œuvre pour des paramètres et modes de brouillage suivant :
   • sectoriel
   • puissance min/max/moyenne
   • pattern spatio-temporel.
2. 2/ Dans une variante du procédé, des consignes peuvent également être élaborées et diffusés aux émetteurs amis.
3. 3/ Le procédé peut aussi être utilisé pour des schémas Spatio Temporels mis en œuvre dans les postes émetteurs amis parmi les suivant:
   • la redondance spatiale simple entre voies Tx et redondance temporelle entre les messages
   • le schéma ST robuste en Rx aux interférences externes (i.e. non Multi-Trajet)
   • l'utilisation de l'une des antennes Tx pour le signal de brouillage sur chaque Tx MIMO ou MISO et des autres antennes Tx pour la communication
   • la formation de "voies spatiale" de brouillage avec un sous-réseau en émission (lacunaire)) de Tx MISO ou MIMO "hybrides" com/brouilleurs.
4. 4/ Le procédé peut aussi être utilisé avec des postes récepteurs amis équipés de filtres Spatio Temporels choisi parmi la liste suivante, donnée à titre illustratif et nullement limitatif :
   • Annulation Brouilleur
   • SIMO par Formation de Voie (FV) ou par Filtrage Adapté Spatial (FAS)
   • Filtre adapté spatio-temporel « optimal » en présence interférence(s) externe(s)
   • Filtre réjecteur exploitant l'a-priori forme d'onde brouilleur connue
   • Filtre réjecteur exploitant l'a-priori direction brouilleur connue (avec ou sans goniométrie préalable du brouilleur)
   • etc.

Different implementation variants of the invention can be broken down according to the nature of the jammers used and the degree of information of the friendly stations on these jammers, and finally according to the processing capacity on board the friendly stations.

1. 1 / The method according to the invention can be implemented for the following scrambling parameters and modes:
   • sectoral
   • min / max / average power
   • spatio-temporal pattern.
2. 2 / In a variant of the method, instructions can also be developed and broadcast to friendly transmitters.
3. 3 / The process can also be used for Spatio Temporal schemes implemented in friend transmitting stations among the following:
   • simple spatial redundancy between Tx channels and temporal redundancy between messages
   • the ST diagram robust in Rx to external interference (ie not Multi-Path)
   • the use of one of the Tx antennas for the jamming signal on each Tx MIMO or MISO and the other Tx antennas for communication
   • the formation of jamming "space paths" with a transmitting subnetwork (incomplete) of Tx MISO or MIMO "hybrid" com / jammers.
4. 4 / The method can also be used with friendly receiver stations equipped with temporal spatial filters chosen from the following list, given by way of illustration and in no way limiting:
   • Jammer Cancellation
   • SIMO by Lane Formation (FV) or by Spatial Adapted Filtering (FAS)
   • "Optimal" spatio-temporal matched filter in the presence of external interference (s)
   • Rejector filter using a priori known interfering waveform
   • Rejector filter using a priori known jammer direction (with or without prior goniometry of the jammer)
   • etc.

• des critères portant sur la minimisation du niveau de signal fratricide moyen ou fratricide+interférent moyen les récepteurs Rx_n en sortie de traitement T_n sur le récepteur Rx_n,
• des critères portant sur la maximisation du rapport entre la puissance de signal utile en sortie de traitement et la puissance de signal de brouillage résiduel en sortie de traitement sur le récepteur Rx_n.

The process of optimizing useful links involves certain criteria linked to the reduction of fratricidal interference and / or to the maximization of the ratio between the power of the useful signal and the power of the fratricidal interference on each receiver Rx _n , which may be write according to the above in several forms, such as the following, showing convex functionals:

• criteria relating to the minimization of the level of average fratricidal or fratricidal signal + average interfering with the receivers Rx _n at the output of processing T _n on the receiver Rx _n ,
• criteria relating to the maximization of the ratio between the useful signal power at the processing output and the residual jamming signal power at the processing output on the receiver Rx _n .

Four criteria which can be applied, from the least complex to the more complex to implement, are given below by way of illustration and without limitation.

JR max threshold type criterion: for each friend receiver Rx _n , this criterion guarantees a level of interference on the signals at the processing output which does not exceed a given interference threshold ΔBr _n . For each friend receiver Rx _n , the parameter sought is only the processing operator in reception of Rx _n in its value domain.

sachant que $$\begin{array}{ll}{\mathrm{\pi }}_{\mathrm{J}\prime \mathrm{jn}}\left({\mathrm{T}}_{\mathrm{n}},{\mathrm{H}}_{\mathrm{J}\prime \mathrm{j},\mathrm{n}}\right)& =\mathrm{tr}\left[\mathrm{J}{\prime }_{\mathrm{jn}}.\mathrm{J}{{\prime }_{\mathrm{jn}}}^{\mathrm{H}}\right]\\ & =\mathrm{tr}\left[{\mathrm{T}}_{\mathrm{n}}.{\mathrm{J}}_{\mathrm{jn}}.{{\mathrm{J}}_{\mathrm{jn}}}^{\mathrm{H}}.{{\mathrm{T}}_{\mathrm{n}}}^{\mathrm{H}}\right]\\ & =\mathrm{tr}\left[\left({\mathrm{T}}_{\mathrm{n}}.{\mathrm{H}}_{\mathrm{J}\prime \mathrm{j},\mathrm{n}}.{\mathrm{B}}_{\mathrm{j}}\right).{\left({\mathrm{T}}_{\mathrm{n}}.{\mathrm{H}}_{\mathrm{J}\prime \mathrm{j},\mathrm{n}}.{\mathrm{B}}_{\mathrm{j}}\right)}^{\mathrm{H}}\right].\end{array}$$

et sachant que les paramètres H_J'_j,n et B_j ne sont pas contrôlés pour l'optimisation du critère mais connus par analyse et mesure et information a priori.For all n = 1, ..., N, it is therefore a question of looking for a parameter T _n in the domain Dom_T which verifies the following thresholding criterion on the sum of the residual fratricidal contributions of the jammers: $${\mathit{JR}}_{\mathrm{not}}={\displaystyle \sum _{j=1}^J{\pi }_{J\prime j,\mathrm{not}}}\left(H_{J\prime j,\mathrm{not}},T_{\mathrm{not}}\right)\le \mathrm{\Delta }{\mathit{Br}}_{\mathrm{not}}$$

knowing that $$\begin{array}{ll}{\mathrm{\pi }}_{\mathrm{J}\prime \mathrm{jn}}\left({\mathrm{T}}_{\mathrm{not}},{\mathrm{H}}_{\mathrm{J}\prime \mathrm{j},\mathrm{not}}\right)& =\mathrm{tr}\left[\mathrm{J}{\prime }_{\mathrm{jn}}.\mathrm{J}{{\prime }_{\mathrm{jn}}}^{\mathrm{H}}\right]\\ & =\mathrm{tr}\left[{\mathrm{T}}_{\mathrm{not}}.{\mathrm{J}}_{\mathrm{jn}}.{{\mathrm{J}}_{\mathrm{jn}}}^{\mathrm{H}}.{{\mathrm{T}}_{\mathrm{not}}}^{\mathrm{H}}\right]\\ & =\mathrm{tr}\left[\left({\mathrm{T}}_{\mathrm{not}}.{\mathrm{H}}_{\mathrm{J}\prime \mathrm{j},\mathrm{not}}.{\mathrm{B}}_{\mathrm{j}}\right).{\left({\mathrm{T}}_{\mathrm{not}}.{\mathrm{H}}_{\mathrm{J}\prime \mathrm{j},\mathrm{not}}.{\mathrm{B}}_{\mathrm{j}}\right)}^{\mathrm{H}}\right].\end{array}$$

and knowing that the parameters H _J ' _{j, n} and B _j are not controlled for the optimization of the criterion but known by analysis and measurement and a priori information.

Min JR type criterion: for each friend receiver Rx _n , this criterion aims to seek a minimum level of interference on the signals at the processing output. For each friend receiver Rx _n , the optimized parameter is only the processing operator in reception of Rx _n in its value domain.

sachant que : $$\begin{array}{ll}{\mathrm{\pi }}_{\mathrm{J}\prime \mathrm{jn}}\left({\mathrm{T}}_{\mathrm{n}},{\mathrm{H}}_{\mathrm{J}\prime \mathrm{j},\mathrm{n}}\right)& =\mathrm{tr}\left[\mathrm{J}{\prime }_{\mathrm{jn}}.\mathrm{J}{{\prime }_{\mathrm{jn}}}^{\mathrm{H}}\right]\\ & =\mathrm{tr}\left[{\mathrm{T}}_{\mathrm{n}}.{\mathrm{J}}_{\mathrm{jn}}.{{\mathrm{J}}_{\mathrm{jn}}}^{\mathrm{H}}.{{\mathrm{T}}_{\mathrm{n}}}^{\mathrm{H}}\right]\\ & =\mathrm{tr}\left[\left({\mathrm{T}}_{\mathrm{n}}.{\mathrm{H}}_{\mathrm{J}\prime \mathrm{j},\mathrm{n}}.{\mathrm{B}}_{\mathrm{j}}\right).{\left({\mathrm{T}}_{\mathrm{n}}.{\mathrm{H}}_{\mathrm{J}\prime \mathrm{j},\mathrm{n}}.{\mathrm{B}}_{\mathrm{j}}\right)}^{\mathrm{H}}\right]\end{array}$$

sachant que les paramètres H_J'_j,n et B_j ne sont pas contrôlés pour l'optimisation du critère mais seulement connus par mesure, analyse et information a priori,For all n = 1, ..., N; it is therefore a question of seeking the reception processing T _n which minimizes the sum of the residual fratricidal contributions of the jammers $${\mathrm{JR}}_{\mathrm{not}}={\displaystyle \sum _{j=1}^J{\pi }_{J\prime j,\mathrm{not}}}\left(T_{\mathrm{not}},H_{J\prime j,\mathrm{not}}\right)$$

knowing that : $$\begin{array}{ll}{\mathrm{\pi }}_{\mathrm{J}\prime \mathrm{jn}}\left({\mathrm{T}}_{\mathrm{not}},{\mathrm{H}}_{\mathrm{J}\prime \mathrm{j},\mathrm{not}}\right)& =\mathrm{tr}\left[\mathrm{J}{\prime }_{\mathrm{jn}}.\mathrm{J}{{\prime }_{\mathrm{jn}}}^{\mathrm{H}}\right]\\ & =\mathrm{tr}\left[{\mathrm{T}}_{\mathrm{not}}.{\mathrm{J}}_{\mathrm{jn}}.{{\mathrm{J}}_{\mathrm{jn}}}^{\mathrm{H}}.{{\mathrm{T}}_{\mathrm{not}}}^{\mathrm{H}}\right]\\ & =\mathrm{tr}\left[\left({\mathrm{T}}_{\mathrm{not}}.{\mathrm{H}}_{\mathrm{J}\prime \mathrm{j},\mathrm{not}}.{\mathrm{B}}_{\mathrm{j}}\right).{\left({\mathrm{T}}_{\mathrm{not}}.{\mathrm{H}}_{\mathrm{J}\prime \mathrm{j},\mathrm{not}}.{\mathrm{B}}_{\mathrm{j}}\right)}^{\mathrm{H}}\right]\end{array}$$

knowing that the parameters H _J ' _{j, n} and B _j are not controlled for the optimization of the criterion but only known by measurement, analysis and information a priori,

This is formally written for each receiver Rx _n : $$\forall \mathrm{not}=1...\mathrm{NOT},T_{\mathrm{not}}=\underset{t_{\mathrm{not}}\in \mathit{Dom}\_T}{\mathit{Arg}\min }\left\{{\mathit{JR}}_{\mathrm{not}}\right\}=\underset{t_{\mathrm{not}}\in \mathit{Dom}\_T}{\mathit{Arg}\min }\left\{{\displaystyle \sum _{j=1}^J{\pi }_{J\prime j,\mathrm{not}}\left(H_{J\prime j,\mathrm{not}},t_{\mathrm{not}}\right)}\right\}$$

quadratique sur la variable t_n, sous la contrainte t_n ∈ Dom_T.Achieving this criterion amounts to solving for all n = 1, ..., N; an optimization problem of the criterion ${\displaystyle \sum _{j=1}^J{\pi }_{J\prime j,\mathrm{not}}\left(H_{J\prime j,\mathrm{not}},t_{\mathrm{not}}\right)}$

quadratic on the variable t _n , under the constraint t _n ∈ Dom_T.

Minimum threshold SJR type criterion:

• la matrice de codage des données utiles à l'émission de Tx_m, soit le paramètre Codage_m ∈ Dom_Codage.
• l'opérateur traitement en réception de Rx_n, soit T_n ∈ Dom_T.

For each transmitter friend Tx _m - receiver friend Rx _n link, this criterion aims to guarantee a power ratio between the useful signal at the processing output and the jamming signal at the processing output which exceeds a given threshold ΔSJR _n corresponding to a quality reception a priori. For each friend Tx _{m transmitter link, friend Rx n} receiver, the desired parameters are here

• the coding matrix of the data useful for the transmission of Tx _m , ie the parameter Coding _m ∈ Dom_Codage.
• the operator processing in reception of Rx _n , that is to say T _n ∈ Dom_T.

• sachant que π_Ymn(Codage_m,H0'_m,n,T_n) = tr[Y_mn.Y_mn ^H] = tr[T_n.X_mn.X_mn ^H.T_n ^H] = tr[T_n.H0'_m,n.Codage_m.Data_m.(T_n.H0'_m,n.Codage_m.Data_m)^H], sachant que le paramètre de canal H₀'_m,n n'est pas contrôlé pour l'optimisation du critère mais connu par analyse et mesure et information a priori,
• sachant que les données utiles Data_m ne sont ni connues ni contrôlées . sachant que π_J'jn(T_n; H_J'_j,n) = tr[J'_jn.J'_jn ^H] = tr[T_n.J_jn.J_jn ^H.T_n ^H] = tr[(T_n.H_J'_j,n.B_j).(T_n.H_J'_j,n.B_j)^H]
• sachant que les paramètres H_J'_j,n et B_j ne sont pas contrôlés pour l'optimisation du critère mais seulement connus par mesure, analyse et information a priori.

For any friend link Tx _m , Rx _n m = 1, ..., M; n = 1, ..., N; it is therefore a question of looking for parameters Coding _m and T _n in the respective domains Dom_Codage and Dom_T which check the following thresholding criterion on the useful signal to boilers ratio: $${\mathit{SJR}}_{m,\mathrm{not}}=\frac{{\pi }_{\mathit{Ym},\mathrm{not}}\left({\mathit{Coding}}_{\mathrm{<figure-callout\; id="0"\; label="m\; H"\; filenames="imgf0003.png,imgf0004.png"\; state="\{\{state\}\}">m</figure-callout>}},H_{},{}_{0\prime m,\mathrm{not}},T_{\mathrm{not}}\right)}{{\displaystyle \sum _{j=1}^J{\pi }_{J\prime j,\mathrm{not}}\left(H_{J\prime j,\mathrm{not}},T_{\mathrm{not}}\right)}}\ge \mathrm{\Delta }{\mathit{SJR}}_{\mathrm{not}}$$

• knowing that π _Ymn (Coding _m , H0 ' _{m, n} , T _n ) = tr [Y _mn .Y _mn ^H ] = tr [T _n .X _mn .X _mn ^H .T _n ^H ] = tr [T _n . H0 ' _{m, n} .Coding _m .Data _m . (T _n .H0' _{m, n} .Coding _m .Data _m ) ^H ], knowing that the channel parameter H ₀ ' _{m, n} is not checked for l '' optimization of the criterion but known by analysis and measurement and information a priori,
• knowing that the payload Data _m is neither known nor controlled. knowing that π _J'jn (T _n ; H _J ' _{j, n} ) = tr [J' _jn .J ' _jn ^H ] = tr [T _n .J _jn .J _jn ^H .T _n ^H ] = tr [( T _n .H _J ' _{j, n} .B _j ). (T _n .H _J ' _{j, n} .B _j ) ^H ]
• knowing that the parameters H _J ' _{j, n} and B _j are not controlled for the optimization of the criterion but only known by measurement, analysis and information a priori.

Max SJR type criteria:

• la matrice de codage des données utiles à l'émission de Tx_m, soit le paramètre Codage_m ∈ Dom_Codage.
• l'opérateur traitement en réception de Rx_n, soit T_n ∈ Dom_T.

For each transmitter friend Tx _m - receiver friend Rx _n link, this criterion aims to guarantee a maximum power ratio between the useful signal at the processing output and the jamming signal at the processing output corresponding to a reception quality which is a priori optimal for the radio environment surrounding the transmission Tx _n <-> Rx _m . For each friend Tx _{m transmitter link, friend Rx n} receiver, the desired parameters are here

• the coding matrix of the data useful for the transmission of Tx _m , ie the parameter Coding _m ∈ Dom_Codage.
• the operator processing in reception of Rx _n , that is to say T _n ∈ Dom_T.

• sachant que π_Ymn(Codage_m,H₀'_m,n,T_n) = tr[Y_mn.Y_mn ^H] = tr[T_n.X_mn.X_mn ^H.T_n ^H] = tr[T_n.H₀'_m,n.Codage_m.Data_m.(T_n.H₀'_m,n.Codage_m.Data_m)^H], sachant que le paramètre de canal H₀'_m,n n'est pas contrôlé pour l'optimisation du critère mais connu par analyse et mesure et information a priori,
• sachant que les données utiles Data_m ne sont ni connues ni contrôlées,
• sachant que π_J'jn(T_n; H_J'_j,n) = tr[J'_jn.J'_jn ^H] = tr[T_n.J_jn.J_jn ^H.T_n ^H] = tr[(T_n.H_J'_j,n.B_j).(T_n.H_J'_j,n.B_j)^H]
• sachant que les paramètres H_J'_j,n et B_j ne sont pas contrôlés pour l'optimisation du critère mais seulement connus par mesure, analyse et information a priori.

For any friend link Tx _m , Rx _n m = 1, ..., M; n = 1, ..., N; it is therefore a matter of looking for parameters Coding _m and T _n which maximize the ratio between the power of the useful signal at the processing output and the sum of the residual fratricidal interference contributions, i.e. which maximize the criterion $${\mathrm{SJR}}_{\mathrm{m},\mathrm{not}}=\frac{{\pi }_{\mathit{Ym},\mathrm{not}}\left({\mathit{Coding}}_{\mathrm{<figure-callout\; id="0"\; label="m\; H"\; filenames="imgf0003.png,imgf0004.png"\; state="\{\{state\}\}">m</figure-callout>}},H_{},{}_{0\prime m,\mathrm{not}},T_{\mathrm{not}}\right)}{{\displaystyle \sum _{j=1}^J{\pi }_{J\prime j,\mathrm{not}}\left(H_{J\prime j,\mathrm{not}},T_{\mathrm{not}}\right)}}$$

• knowing that π _Ymn (Coding _m , H ₀ ' _{m, n} , T _n ) = tr [Y _mn .Y _mn ^H ] = tr [T _n .X _mn .X _mn ^H .T _n ^H ] = tr [T _n .H ₀ ' _{m, n} .Coding _m .Data _m . (T _n .H ₀ ' _{m, n} .Coding _m .Data _m ) ^H ], knowing that the channel parameter H ₀ ' _{m, n} is not controlled for the optimization of the criterion but known by analysis and measurement and information a priori,
• knowing that the payload Data _m is neither known nor checked,
• knowing that π _J'jn (T _n ; H _J ' _{j, n} ) = tr [J' _jn .J ' _jn ^H ] = tr [T _n .J _jn .J _jn ^H .T _n ^H ] = tr [( T _n .H _J ' _{j, n} .B _j ). (T _n .H _J ' _{j, n} .B _j ) ^H ]
• knowing that the parameters H _J ' _{j, n} and B _j are not controlled for the optimization of the criterion but only known by measurement, analysis and information a priori.

This is formally written

réaliser ce critère revient à résoudre pour tout m= 1,...,N et n= 1,...,N un problème d'optimisation du critère (quadratique sur la variable codage cod_m) ${\mathrm{SJR}}_{\mathrm{m},\mathrm{n}}=\frac{{\pi }_{\mathit{Ym},n}\left({\mathit{cod}}_m,H_{0\prime m,n},t_n\right)}{{\displaystyle \sum _{j=1}^J{\pi }_{J\prime j,n}\left(H_{J\prime j,n},t_n\right)}}$

pour les variables cod_m et t_n, et sous les contraintes cod_m ∈ Dom_Codage et t_n ∈ Dom_T. $$\forall m=1..M;\mathrm{not}=1...\mathrm{NOT},T_{\mathrm{not}}=\mathit{ArgMax}\left\{{\mathit{SJR}}_{m,\mathrm{not}}\right\}=\underset{\begin{array}{c}{t}_{\mathrm{not}}\in \mathit{Dom}\_T\\ \mathit{cod}\_m\in \mathit{Dom}\_\mathit{Encodings}\end{array}}{\mathit{ArgMax}}\left\{\frac{{\pi }_{\mathit{Ym},\mathrm{not}}\left({\mathit{<figure-callout\; id="0"\; label="cod\; m\; H"\; filenames="imgf0003.png,imgf0004.png"\; state="\{\{state\}\}">cod</figure-callout>}}_m,H_{},{}_{0\prime m,\mathrm{not}},t_{\mathrm{not}}\right)}{{\displaystyle \sum _{j=1}^J{\pi }_{J\prime j,\mathrm{not}}\left(H_{J\prime j,\mathrm{not}},t_{\mathrm{not}}\right)}}\right\}$$

to achieve this criterion amounts to solving for all m = 1, ..., N and n = 1, ..., N a problem of optimization of the criterion (quadratic on the coding variable cod _m ) ${\mathrm{SJR}}_{\mathrm{m},\mathrm{not}}=\frac{{\pi }_{\mathit{Ym},\mathrm{not}}\left({\mathit{<figure-callout\; id="0"\; label="cod\; m\; H"\; filenames="imgf0003.png,imgf0004.png"\; state="\{\{state\}\}">cod</figure-callout>}}_m,H_{},{}_{0\prime m,\mathrm{not}},t_{\mathrm{not}}\right)}{{\displaystyle \sum _{j=1}^J{\pi }_{J\prime j,\mathrm{not}}\left(H_{J\prime j,\mathrm{not}},t_{\mathrm{not}}\right)}}$

for the variables cod _m and t _n , and under the constraints cod _m ∈ Dom_Codage and t _n ∈ Dom_T.

Example 1: cooperative barrier jamming

This particular example of implementation of the invention applies to the optimization of the scrambling of a tactical barrier in the presence of friendly frequency evasion communication stations, a process which was the subject of the Applicant's patent under the number EP 1303069 .

It is shown below how the general process of the invention described above is available for this particular application.

The barrier jammer or the barrier jammer network has the ability to interrupt transmissions on certain time slots and certain frequency channels, by following certain pseudo-random laws. This capacity is a priori known to the friendly stations, as well as the main possible settings which correspond to it, in particular the frequency plans and pseudo-random laws corresponding to the slots unoccupied by the scrambling signals.

P tactical posts present in the theater are to be scrambled, denoted Ci _p , p = 1, ..., P. These posts are of known or unknown positions. The services they use and the corresponding operating points are assumed to be known to the jammers as well as their characteristics (interference / denial thresholds of the various services, operating margins, etc.). The jammers adapt the settings of their barrage interference waveform.

N frequency-hopping friendly transmitters and receivers seek to preserve and preserve their communication links, denoted R _n n = 1, ..., N. These transmitters / receivers are in positions approximately known and under the control of local communication nodes called NLCs (in a simplified implementation of the invention, the NLCs can be for example the friendly transmitters of each useful link, in a more elaborate implementation, the NLCs can be infrastructure components with local scope, relay, "master" transmission stations dedicated to command, etc.)

• ∘ évaluer les risques d'interférences induites par les signaux de brouillage sur les récepteurs qu'il contrôle (ou sur ceux qui sont à préserver).
• ∘ rechercher les slots temporels et les canaux fréquentiels inoccupés par les signaux de brouillage.
• ∘ piloter en conséquence les émissions des postes sous son contrôle de manière à faire coïncider leurs émissions avec les canaux fréquentiels et avec les slots temporels non-occupés par les signaux de brouillage.

The positions of the jammers, the positions of the transmitters and friendly receivers under its control and the panel of usable waveforms and associated settings are known to each NLC, local controller node. For example, the frequency hopping laws, and where appropriate, the slot channels and transmission powers as well as the waveforms used can be chosen by the NCL, or even controlled by means of a synchronization signal transmitted to the stations it controls (slave stations). In addition, the NCLs have analysis module sensing functions or associated interception capabilities which allow them to conduct measurements both on the transmitters / receivers whose positions they know, on the useful signals which they control. / know the transmissions and the reception processing of slave stations, but also the interfering signals that they do not control but of which they know the main possible characteristics that they can find by in situ measurement. Each NLC can therefore, according to its measurements and a priori information on the interference waveforms and on the stations under its control:

• ∘ assess the risks of interference caused by the jamming signals on the receivers it controls (or on those which must be preserved).
• ∘ search for time slots and frequency channels unoccupied by jamming signals.
• ∘ consequently control the transmissions from the stations under its control so as to make their transmissions coincide with the frequency channels and with the time slots not occupied by the jamming signals.

• de piloter les émissions EVF des communications utiles, sur les créneaux temporels ou slots temps/fréquence laissés vide par les brouilleurs,
• de contrôler au cours du temps la position des émetteurs récepteurs des liens utiles pour garantir (en gérant certaines marges de puissance et certains intervalles temporels de garde) la non-collision des signaux utiles avec les signaux brouilleurs malgré les temps de propagation différents desdits signaux,
• dans le cas de postes mobiles à vitesse rapide, de contrôler au cours du temps le Doppler des émetteurs récepteurs des liens utiles pour garantir (en gérant certaines marges de puissance et certains intervalles fréquentiels de garde) la non-collision des bandes des signaux utiles avec celles des signaux brouilleurs malgré les vitesses relatives différentes des émetteurs desdits signaux.

The process of applying the method according to the invention can be indexed frame by frame. The k-th frame will be denoted t _k . It is then for a local controller node NLC for each frame:

• to control the EVF transmissions of useful communications, on time slots or time / frequency slots left empty by jammers,
• to control over time the position of the transceivers of the useful links to guarantee (by managing certain power margins and certain time intervals of guard) the non-collision of the useful signals with the interfering signals despite the different propagation times of said signals,
• in the case of mobile stations at high speed, to control the Doppler of the transceivers of the useful links over time to guarantee (by managing certain power margins and certain frequency guard intervals) the non-collision of the bands of useful signals with those of interfering signals despite the different relative speeds of the transmitters of said signals.

In many cases the propagation times of the ground-to-ground communication signals over a few tens of kilometers at most are negligible compared to the durations of the useful stages. Likewise, the Doppler shifts corresponding to slow platforms are negligible compared to the bands of useful emissions. The physical problem is simplified and therefore reduced to the determination of the instants of the start of the transmissions and of the channels corresponding to these transmissions by the local communications node (NLC). In more complex cases of long-distance propagation from mobile platforms (communication on scrolling aircrafts and satellites, for example), the NLC must also take into account the relative propagation and Doppler times).

Direct deterministic resolution of the optimization problem

If the local communication node NLC is ideal, knows or knows how to restore by its measurement, the slots and frequency channels left free by the jammer (s) on the present and future frames and if it knows exactly the "slave" stations under risk of jamming and finally if he knows exactly how to place the slots of his "slave" stations on the slots left free by the jammer (s) without spilling over to the adjacent frequencies or to the adjacent slots, the previous optimization problem is simplified in the form of a resource allocation problem. There is in fact no fratricidal impact of the scrambling on the useful links since the NLC can impose the following instruction on the slave stations at risk of scrambling: for each frame t _k , distribute the transmissions and receptions for the links under scrambling useful signals on the slots left free by the scrambler, allocate the free slots and channels to the transmitters and receivers for this slaves according to a priority management strategy, according to a latency management strategy or according to a random competitive strategy of the ALOHA type, or according to any strategy conventionally used in radio access technologies.

Note that in this implementation of the invention, the precise knowledge of the positions of the slave stations and the jammers by the local communication node provides material for further optimizations while remaining very simple: for example the knowledge of the directivity positions and orientations of the jamming antennas and the knowledge of the position of the slave stations allow the NLC to reproduce by simple models (link assessment) the risks of jamming of its slave stations, and to select a priori only the slave stations which are actually under threat of interference in the above-mentioned resource allocation strategy. The measurements carried out by the NLC and reported, if necessary, by the slave stations to the NLC via the return channels of the friendly links only serve to reinforce the allocation strategy by confirming the absence of fratricidal interference or their low levels on the slots. allocated.

If we push this variant to the extreme, it is even possible to consider the implementation of the invention in an even more simplified framework with an NLC not performing any measurement and simply informed a priori of the channels and time slots left. free from interference; said information comes for example from a known law of the scrambler and of the NLC decided in advance, or else said information being encoded in the scrambling signal itself and decoded by the NLC in its analysis of the scrambling signal, or else said information being obtained by decoding information transmitted in a tagging or triggering signal associated with the scrambler.

Case of multiple jammers with faults + taking into account of interference budgets estimated by using the a priori information of the measurements and of propagation models

• Temps de descente et de montée du signal de brouillage induisant une durée de disponibilité du slot inférieure à la durée slot, ce qui réduit d'autant la durée transmission exploitables dans les slots de brouillage laissés vides,
• Débordement spectral du signal de brouillage sur une partie des canaux laissés vides, en raison d'un filtrage insuffisant du spectre des signaux de brouillage, ce qui réduit d'autant la bande de transmission utile dans les canaux laissés vides de brouillage
• Bilans de liaison entre les brouilleurs Br_j et les récepteurs utiles R_n modélisés par des coefficient de perte L_j,n induisant un niveau en entrée L_j,nP_j (P_j : puissance isotrope rayonnée équivalente à l'émission par le brouilleur d'indice j). Ces niveaux d'entrées peuvent être estimés par les récepteurs amis (au moins le NLC, voire les récepteurs esclaves le cas échéant) d'après la connaissance a priori (ou d'après la récupération par analyse des signaux de brouillage) de la PIRE émise, d'après la connaissance des positions et caractéristiques angulaires respectives des émetteurs amis des récepteurs amis et des brouilleurs, et d'après un modèle de propagation simplifié (suffisamment représentatif des phénomènes d'atténuation dans les bandes de fréquence concernées pour la topologie de terrain concerné et pour les distances entrant en jeu). Ces informations, lorsqu'elles sont relatives aux brouilleurs, proviennent par exemple de stratégies connues à l'avance des récepteurs amis (au moins connues du NLC) dont la mise en œuvre est aisément reconnaissable à l'analyse des signaux de brouillage ; ou bien ces informations étant codées dans le signal de brouillage lui-même et décodées par le NLC dans son analyse du signal de brouillage ; ou bien ces informations étant codées dans un signal de taggage associé au brouilleur, par exemple selon le procédé décrit dans la demande de brevet FR 1203071 du demandeur.
• Seuil ΔJR_n de fonctionnement relatif au récepteur ami Rx_n (selon leur service de transmission), traduisant une condition de la forme [Σ_j L_j,nP_j] < ΔJR_n, condition devant être vérifiée par la puissance cumulée des nuisances [Σ_j L_j,nP_j] induites par l'ensemble des brouillages fratricides, nuisances évaluées d'après les estimation de puissance P_j propres à l'émission de chaque brouilleur et d'après le bilan de liaison L_j,n estimés pour chaque lien brouilleur Br_j - récepteur Rx_n. La condition précitée traduit de manière (ici simplifiée mais suffisante et efficace dans de nombreux cas de mise en œuvre de l'invention) la capacité de réception du lien utile Tx_m Rx_n dans des conditions de bruit + brouillage acceptables. Elle peut être évaluée a priori assez simplement à partir de la connaissance a priori des schémas de brouillage ou de leur reconnaissance in situ par analyse, et par un modèle de bilan de liaison. Elle peut être confortée in situ par mesure de Rx_n sur les signaux de brouillage.

The above examples and variants of implementation of the invention extend directly to taking into account the imperfections of one or more jammers, the powers and directivities in transmission of said jammers, the directivities in reception of friendly receivers. , attenuations and propagation filters from jammers to friendly receivers, as well as operating thresholds for friendly receivers:

• Fall and rise time of the jamming signal inducing a slot availability period less than the slot duration, which correspondingly reduces the transmission time usable in the jamming slots left empty,
• Spectral overflow of the jamming signal on a part of the channels left empty, due to insufficient filtering of the spectrum of the jamming signals, which correspondingly reduces the useful transmission band in the channels left empty of interference
• Link balances between jammers Br _j and useful receivers R _n modeled by loss coefficients L _{j, n} inducing an input level L _{j, n} P _j (P _j : radiated isotropic power equivalent to the emission by the jammer index j). These input levels can be estimated by the friendly receivers (at least the NLC, or even the slave receivers if applicable) from the a priori knowledge (or from the recovery by analysis of the jamming signals) of the EIRP. transmitted, according to the knowledge of the respective positions and angular characteristics of the transmitters friendly to the friendly receivers and to the jammers, and according to a simplified propagation model (sufficiently representative of the attenuation phenomena in the frequency bands concerned for the topology of land concerned and for the distances involved). This information, when it relates to the jammers, comes for example from strategies known in advance to friendly receivers (at least known to the NLC), the implementation of which is easily recognizable by analyzing the jamming signals; or this information being encoded in the scrambling signal itself and decoded by the NLC in its analysis of the scrambling signal; or else this information being encoded in a tagging signal associated with the scrambler, for example according to the method described in the patent application FR 1203071 of the applicant.
• Operating threshold ΔJR _n relating to the friend receiver Rx _n (depending on their transmission service), reflecting a condition of the form [Σ _j L _{j, n} P _j ] <ΔJR _n , a condition that must be verified by the cumulative power of the nuisances [ Σ _j L _{j, n} P _j ] induced by all fratricidal interference, nuisances evaluated according to the power estimate P _j specific to the emission of each jammer and according to the estimated _{link budget L j, n} for each interfering link Br _j - receiver Rx _n . The aforementioned condition translates in a manner (simplified here but sufficient and efficient in many cases of implementation of the invention) the reception capacity of the useful link Tx _m Rx _n under acceptable noise + interference conditions. It can be evaluated a priori quite simply on the basis of a priori knowledge of the scrambling patterns or their recognition in situ by analysis, and by a link budget model. It can be reinforced in situ by measuring Rx _n on the jamming signals.

• Seuil ΔSJR_m,n de fonctionnement relatif aux liens utiles entre émetteur ami Tx_m récepteur ami Rx_n (selon leur service de transmission), traduisant une condition de la forme π_Ym,n / [Σ_j L_j,nP_j] > ΔSJR_n, condition devant être vérifiée par le rapport entre la puissance utile reçue π_Ym,n mesurée et la puissance cumulée des nuisances [Σ_j L_j,nP_j] induites par l'ensemble des brouillages fratricides, nuisances évaluées d'après les estimation de puissance P_j propres à l'émission de chaque brouilleur et d'après un modèle de bilan de liaison L_j,n estimés pour chaque lien brouilleur Br_j - récepteur Rx_n. La condition précitée traduit de manière (ici simplifiée mais suffisante et efficace dans de nombreux cas de mise en œuvre de l'invention) la capacité d'établissement et/ou du maintien du lien utile Tx_m Rx_n dans des conditions acceptables. Elle peut être évaluée assez simplement à partir de la connaissance a priori des schémas de brouillage ou de leur reconnaissance in situ par analyse, par un modèle de bilan de liaison (le cas échéant conforté par mesure analyse in situ de Rx_n sur les signaux brouilleurs), et à partir des mesures de niveau reçu sur le signal utile.

The optimization problem is then solved in a very simplified way by a resource re-allocation strategy, here conditional on the thresholding ΔJR _n : the fratricidal effects on friendly stations remain limited and not significant as soon as the NLC can impose the instruction. next to slave stations at risk of interference (ie for which we would have [Σ _j L _{j, n} P _j ]> ΔSJR _n in the absence of re-allocation and in the presence of interference signals corresponding to the received power evaluations P ₁ ... P _J ): for each frame t _k , reallocate the links at risk of interference the transmissions and receptions of useful signals on the slots left free by the jammer, allocate for this the slots and free channels to the transmitters and slave receivers at risk of interference according to a priority management strategy, according to a latency management strategy or according to a random competitive strategy of the ALOHA type, or according to any strategy conventionally used in radio access techniques.

• Operating threshold ΔSJR _{m, n} relating to useful links between transmitter friend Tx _m receiver friend Rx _n (depending on their transmission service), reflecting a condition of the form π _{Ym, n} / [Σ _j L _{j, n} P _j ]> ΔSJR _n , condition to be verified by the ratio between the useful power received π _{Ym, n} measured and the cumulative power of the nuisances [Σ _j L _{j, n} P _j ] induced by all the fratricidal interference, nuisances assessed according to the power estimates P _j specific to the transmission of each jammer and from a link budget model L _{j, n} estimated for each interfering link Br _j - receiver Rx _n . The aforementioned condition translates in a manner (simplified here but sufficient and effective in many cases of implementation of the invention) the ability to establish and / or maintain the useful link Tx _m Rx _n under acceptable conditions. It can be evaluated quite simply from a priori knowledge of the interference patterns or their recognition in situ by analysis, by a link budget model (if necessary supported by measurement in situ analysis of Rx _n on the interfering signals ), and from the level measurements received on the wanted signal.

The optimization problem is solved here again in a very simplified way by a strategy of resource reallocation, here conditional on the thresholding ΔSJR _n : the fratricidal effects on friendly stations remain limited and not significant as soon as the NLC can impose the following instruction at the slave stations under risk of interference (ie for which we would have π _{Ym, n} / [Σ _j L _{j, n} P _j ] <ΔSJR _n in the absence of re-allocation and in the presence of corresponding interference signals to the received power evaluations P ₁ ... P _J ): for each frame t _k , reallocate the links at risk of jamming the transmissions and receptions of useful signals on the slots left free by the scrambler, allocate the slots for this and free channels to slave transmitters and receivers at risk of scrambling according to a priority management strategy, according to a latency management strategy or according to a random competitive strategy of the ALOHA type, or according to any strategy conventionally used in radio access techniques.

Claims (8)

1. Method for minimizing in an adaptive and decentralized manner the fratricidal effects induced by the jamming of P predefined zones ZB or positions in a communications network comprising friendly transmitters, jammers and friendly receivers, said network comprising N_pl platforms, a number M ≤ N_pl of said platforms, termed friendly transmission platforms being equipped with antennas and with systems for transmitting useful transmission signals configurable in a dynamic manner, a number N ≤ N_pl of said platforms, also termed friendly, being equipped with antennas and dynamically configurable systems for receiving useful transmission signals, a number J ≤ N_pl of said platforms being equipped with jamming systems and antennas having characteristics known to the friendly transmission and reception platforms, said jamming systems and antennas being adapted for preventing the transmissions between entities external to said network of friendly platforms, said platforms constituting a network, said method comprising at least the following steps:

   • E₀: Establishing a local reception situation: at the level of each of the N friendly reception platforms (12 r, 13) measuring, E₁, the friendly communication signals Su received by said platforms originating from the M friendly transmitters (10 e, 11), on the basis of said measurements, for each of the N friendly reception platforms, estimating, E₂, the M useful levels received and the M useful propagation channels, N*M estimates,

   • E₃ : Establishing a local jamming situation: at the level of each of the N friendly reception platforms (12 r, 13) measuring, E₄, the jamming signals received by said friendly reception platforms originating from the J jammers (14, 15b), on the basis of the measurements of the jamming signals, for each of the N friendly reception platforms, estimating, E₅, the J fratricidal jamming levels received and the J fratricidal jamming channels, N*J estimates in all,

   • ascertaining a priori the waveforms of the jamming signals and the associated parametrizations, on the basis of the states of the local situations of jamming established by each of the N receiving platforms on the J signals originating from the J jammers, on the basis of the local reception situation established by each of the N receiving platforms on the useful communication signals Su; determining for each of the M friendly transmitting platforms and for each of the N friendly receiving platforms, at least one of the following configuration parameters: a frequency plan, and/or temporal positionings of the transmissions, antenna diagrams and/or orientations, radio access schemes and modulation/coding schemes for the signals transmitted and received, the parameter or parameters being adapted for minimizing or eliminating the fratricidal effects on the N friendly reception platforms,

   • using said configuration parameters in transmission and/or reception for the M friendly transmission platforms and the N friendly reception platforms.
2. Method according to claim 1, characterized in that, after defining a first set of configuration parameters for the M friendly platforms and for the N friendly platforms, steps E₀ to E₅ are repeated over time so as to maintain and optimize the configuration parameters for the platforms.
3. Method according to claim 1, characterized in that it uses the measurement of the propagation channels originating from the J jamming platforms to recognize in situ a predefined and known jamming strategy so as to jointly optimize the transmission and the quality of the transmissions useful at the level of the friendly transmitting and receiving platforms by adapting the transmission power levels and/or the frequency plans and/or the temporal positioning of the transmissions and/or the spatio-temporal coding schemes and/or the radioelectric resource access protocols employed by the friendly transmitters and receivers.
4. Method according to claim 1 or 2, characterized in that it uses jamming signals which code, in a manner known to the friendly receivers, the information useful to the friendly transmitters and receivers so as to inform the latter of the jamming strategy employed, of the characteristics of the jamming waveforms and associated parameters, transmission power, type of diagram and orientation of the antennas, position, altitude, to facilitate the joint optimization of the transmissions and reception processings of the transmissions useful at the level of the friendly transmitting and receiving platforms, said coded information being reconstructed by the analysis of the jamming signals received by the friendly receivers or being decoded in the jamming signals received by the friendly receivers.
5. Method according to claim 1, 2 or 3, characterized in that it uses programmable friendly transmitters and receivers adapted for taking dynamic account of transmission setpoints, regarding the power and/or regarding temporal parameters, the waveform, the spatio-temporal codings, the amplitude phase weighting of the antenna elements.
6. Use of the method according to one of claims 1 to 5 in transmission networks using the MIMO, MISO, SIMO or SISO protocols with or without return pathway from the friendly receivers to the friendly transmitters.
7. Use of the method according to one of claims 1 to 5 in a radio network comprising receivers adapted for measuring values of transmission channels on the useful transmitters and on the jammers.
8. Use of the method according to one of claims 1 to 5 in a radio network comprising one or more reception posts comprising antennal elements coupled to an interceptor which is adapted for performing transmission channel measurements on the useful transmitters and on the jammers.

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