Method for dynamically allocating resources for radio wave communication in an interference situation

Abstract

Method for dynamically allocating resources for radio wave communication between a base station (10) of a communication network and user equipment (25). The method comprises, in response to a detection (E0) of interference between the base station (10) and one or more user equipment (25), a step of assigning (E1) the user equipment (25) to at least two classes of user equipment depending at least on a level of impact of the detected interference on the communication between the respective user equipment and the base station.Then, depending on the assignment, for user equipment of at least one high interference class, change (E3a) of at least one frequency band or sub-band for their communication with the base station, for user equipment of at least one low interference class, maintenance (E3b) unchanged of the frequency bands and sub-bands for their communication with the base station. There is also a configuration (E3c) of beams from the base station (10) to user equipment (25) of at least one interference class different from the high interference class. Abstract figure: 7.

Description

Title of the invention: Method for dynamic allocation of resources for communication by radio waves in an interference situation

[0001] The invention falls within the field of telecommunications by radiofrequency waves, on a network comprising base stations communicating with user equipment which may be dispersed over a territory. It concerns the response to a situation of frequency interference of the communication between a base station and certain user equipment present in the territory in which the base station and the user equipment face interference.The network concerned inevitably has limited resources, in particular limited spectrum resources, that is to say that the base station does not have an infinite choice of frequencies on which to transmit to communicate with a particular user equipment, the spectrum band being limited, and must therefore make choices or even compromises in certain circumstances. These choices or compromises are complicated by the presence of interference which, in a part of the territory, makes it difficult to use a certain part of the communication frequencies initially envisaged.

[0002] The communication networks used are cellular mobile telephone communication networks, such as 5G networks or networks developed from 5G technologies, and also military radio frequency wave communication networks based on base stations or a communication master, which may be a local master on the ground among other local masters on the ground, or possibly a single communication master, not necessarily on the ground.

[0003] From the document "A study of 5G New radio and its vulnerability to jamming" FFI Norwegian Defence Research Establishment 22 / 00906, we know of various very preliminary avenues for combating jamming. These avenues are the provision of additional power to user equipment, the formation of directional beams between the base station and user equipment (beamforming), the use of additional antennas for the user equipment, the use of massive MIMO technology (multiple inputs, multiple outputs, with interference between antennas) to perhaps detect and eliminate the interference, the modification of physical layer parameters such as for example an increase in tolerance to high retransmission rates, or a switch by the user equipment to an available and undisturbed frequency band.

[0004] Thus, the various known anti-jamming solutions are at a preliminary stage and cannot be implemented simultaneously or in combination. The simple frequency foldback solution is implemented in a very indifferent manner. Performance is impacted by the limitation of the spectral band used. The directional beamforming solution is sometimes insufficient, as jamming can remain effective despite the directional beamforming.

[0005] In this context, the invention consists of a method for dynamically allocating resources for communication by radio waves between a base station of a communication network and user equipment.

[0006] The method comprises, in response to a detection of interference between the base station and one or more user equipments, a step of assigning the user equipments to at least two classes of user equipments depending at least on a level of impact of the detected interference on the communication between the respective user equipment and the base station.

[0007] Then, depending on the assignment, the method comprises - for user equipment of at least one high interference class, a change of at least one frequency band or sub-band for their communication with the base station, - for user equipment of at least one non-high interference class, maintaining essentially unchanged the frequency bands and sub-bands for their communication with the base station, - as well as configuration of beams from the base station to user equipment, at least some of which are in the non-high interference class.

[0008] Thanks to this method, spectral resources are preserved: some users escape interference thanks to the frequency change, and others escape it thanks to beam formation, and overall a high quality of service is achieved despite a moderate expenditure of resources, since only limited frequency changes are carried out.

[0009] If the beams were already formed at the time of detection of the interference, the beams of the low interference classes are maintained, or even improved, by taking into account the interference and the reconfiguration of the spectral resources which is carried out in parallel.

[0010] And certain users who are already protected from interference, or who can be effectively protected by beam enhancement, keep the same frequency according to the invention, to keep fallback frequencies available for highly interfered users, for whom beamforming is not highly effective in protecting them from interference.

[0011] If beams were not formed at the time of jamming detection, beams are created for users who are jammed but are not in high jamming class. And a frequency change is performed for users most jammed readers, and according to the invention only for them, so as to optimally use spectral resources.

[0012] Thus, according to the invention, certain users experiencing interference without experiencing it as much as others, benefit from a beam configuration and retain the frequency bands initially allocated to them, and other users, more impacted than the first and selected on this basis to be limited in number, benefit from a new frequency band or frequency sub-band allocation. The limited number of users benefiting from a new frequency allocation makes it possible to manage, without wasting it, the limited resource of available frequency ranges.

[0013] The following features are optional and advantageous: - the change of at least one frequency band or sub-band can be carried out towards at least one other band or sub-band, identified by power spectral density measurement, evaluated at the level of a set of user equipment. - the change of at least one frequency band or sub-band may include an activation of contiguous frequency blocks, in particular Bandwidth parts in the 5G standard, or even disjoint frequency blocks or an activation of frequency blocks for carrier aggregation. The activation may be done simultaneously with a deactivation of other frequency blocks. - the beam configuration may further comprise a beam modification for a user equipment of a high interference class after changing at least one frequency band or sub-band for the communication of said user equipment with the base station, to maximize the gain for an uplink or for a downlink to said user equipment. - changing at least one frequency band or sub-band may include determining a jammed spectral band of a user equipment by analyzing the physical resource blocks allocated by the scheduling processor. - assignment to classes can also be done by taking into account beamforming weights formed prior to the detection of interference between user equipment and the base station. - assignment to classes can also be done using location information or positioning techniques. - the network being a 4G or later cellular network, assignment to classes can be done using information natively collected by the base station. - the method may further comprise a beam configuration, by implementing a massive MIMO antenna function, comprising in particular for high interference class user equipment a coordinated scheduling of multiple spatially separated beams on the same time and frequency resources. - the method may further comprise a beam configuration which opens, by implementing a massive MIMO antenna function, beams directed more widely towards users of a low interference class than towards users of a high interference class.

[0014] The description of the invention will be continued in relation to the figures, presented for illustrative purposes and among which

[0015] Figures 1 and 2 show interference situations impacting certain user equipment in an area covered by a base station.

[0016] [Fig.3] shows the use of beamforming in such a situation.

[0017] [Fig.4] shows the general process of the invention.

[0018] [Fig.5] shows a first step of an embodiment of the invention.

[0019] [Fig.6] shows a decision-making step after the preliminary step.

[0020] [Fig.7] shows the implementation of the central step of an embodiment of the invention.

[0021] [Fig.8] shows a particular aspect of an embodiment of the invention.

[0022] In [Fig. 1], a base station 10 is shown in the context of a cellular telephone network, on the ground or on a building resting on the ground and assumed to be fixed, transmitting in a coverage area 20 with a frequency range FL. The good transmission of communications in a part of the coverage area 20 is hindered by a jammer 50, placed on the ground or on a building or vehicle resting on the ground and assumed to be fixed, which transmits jamming waves in a jamming zone 60 which has an intersection with the coverage area 20.The user equipment present in the coverage area 20, which is intended to communicate in uplinks and downlinks with the base station 10, is either outside the interference area 60, and is qualified as unaffected user equipment 25, because its uplink or downlink communication with the base station 10 is not affected by the interference, or in the interference area 60, and is then qualified as jammed user equipment 65. The base station 10 presented in [Fig.l], by way of illustration, only transmits on an angular sector around it, and is therefore present rather on the periphery of the coverage area 20. But it can also be at the center thereof, transmitting in all directions. In the same way, the jammer can be omni-directional, even if it often concentrates its power in a given direction.

[0023] In [Fig.2], a similar representation is shown, the base station 10 this time being shown inside its coverage area 20 - it transmits in all di horizontal sections. In [Fig. 2], moreover, no user equipment is shown in the jamming zone 60. On the other hand, the base station 10 is inside the jamming zone 60, whereas it is not in [Fig. 1]. Thus, finally, due to the presence in the jamming zone 60 of the base station 10, all user equipment are jammed user equipment 65, even if the level of interference can be variable, from low to high. [Fig. 2] also shows by a directional symbol that the jamming is an uplink jamming: the signals are emitted by the jammer 50 towards the terrain that the people organizing the jamming seek to impact.

[0024] [Fig. 3] shows the beamforming that is used in response to detection by network operators or IT of the network, or of the base station 10. Directional beams 90 are used to communicate between the base station 10 and each of the user equipments. These beams overlap over a small part of their length and width with the jamming zone 60 (case of [Fig. 3], from [Fig. 2]), or even for some of them, do not overlap at all with it, if the base station 10 is not located in the jamming zone 60 (case not shown which would be from [Fig. 1]). These user equipments are referred to as recovered user equipments 26, because they have, after the introduction of beamforming, a communication quality close to that of the unaffected user equipments 25.Beamforming, for each of them, has the consequence of obtaining a higher gain, in the solid angle of the beam, which makes it possible to overcome the jamming power. This higher gain is obtained in transmission (downlink) and in reception (uplink). Beamforming also has the effect of developing interference rejection or attenuation (null steering or zero forcing in English, or application of zeros) in the direction of the jammer 50, which is, relative to the base station 10, in a direction which does not coincide with any of the formed beams.

[0025] [Fig.4] shows the general process of the invention. A step E1 of partitioning the user equipment is carried out, then it is followed by a step E2 of defining a configuration strategy of the base station, including the spatial configuration and the frequency configuration, then by a step E3 of implementing the strategy, and finally a step E4 of allocating the antenna elements. A step E5 following step E4 is indicated to show the return to step E1, because the process is a permanent, uninterrupted loop process.

[0026] [Fig.5] shows the initial step of the invention, by which in response to a detection E0 of a suspicion of interference for a user equipment, for example by identifying a low signal to interference plus noise ratio (SINR) in abscissa x in view of a value of received power of reference signal (RSPR in English Reference Signal Received Power) in y-axis, the user equipment present in the coverage area 20 (figures 1 or 2) is classified into several categories. This is the step El of partitioning the user equipment. This classification can be carried out before beam formation, or after it by taking into account information measured or obtained once the beams have been formed.

[0027] The categories, or clusters, may be, if established before beamforming, three in number, in which case they are the low interference, medium interference and high interference categories.

[0028] They can also be of two categories, in particular if they are established after beam formation: the category of user equipment with persistent interference after beam formation and the category of user equipment not requiring additional measurement beyond beam formation.

[0029] From the moment when one or more user devices are classified in a medium or strong interference category (3-category classification), or persistent (two-category classification), an anti-jamming strategy according to the invention, i.e. by frequency modification, is implemented. [Fig.5] nevertheless stops at the formation of the categories.

[0030] To establish these categories, a partitioning process of all the user equipment known to the base station 10 as being present in its coverage area 20 is carried out, by an artificial intelligence process such as machine learning, which may be a support vector machine SVM, a K nearest neighbors KNN method, a k-means partitioning, or a decision tree forest method.

[0031] The decision-making process is carried out on the basis of the data initially obtained, namely the spectral and spatial characteristics associated with each user equipment and the interference levels observed.

[0032] Each jammed user equipment is, for the purpose of partitioning, characterized spectrally, and also spatially.

[0033] The spectral characterization is done by identifying the spectral bands and sub-bands impacted by the jammer. For this, the process step that is implemented is: - obtaining and reading the physical resource blocks allocated by the scheduler in charge of the base station to know the jammed spectral band.

[0034] As for spatial characterization, this is done with location information if such information is available or via beam directionality if beamforming has been applied. Doppler positioning techniques, uplink arrival time lag analysis UTDOA, IA, etc. are used. If beamforming has been engaged, the beamforming amplification factors (weights) or beam identifiers are spatial location indicators used for spatial characterization.

[0035] [Fig.5] shows a machine learning implementation, carried out by comparing signal-to-interference-plus-noise ratio (SINR) data on the x-axis (in logarithmic scale), and reference signal received power (RSRP) on the y-axis (in logarithmic scale) at times t and t-1. The algorithm determines a boundary, a hyperplane which is here a line, between - user equipment considered as unaffected 100 (SINR, therefore abscissa x rather high for an RSRP therefore ordinate y proportionally rather low) - and those considered to be jammed 110 (SINR rather low for a proportionally rather high RSPR).

[0036] The partitioning can be done by generally using input data from measurements natively collected in 4G or 5G or later cellular telephony, such as the channel quality information CQI Channel Quality Indicator, the number of retransmissions linked to #NACK Not-Acknowledged and the modulation and coding scheme MCS Modulation and Coding Scheme.

[0037] Partitioning may be based on spectral data (spectral clustering) or involve hierarchical clustering.

[0038] The partitioning used leads to a grouping of user equipment, which in each group have a strong spectral, spatial, and interference class similarity.

[0039] In [Fig.6], step E2 of defining the base station configuration strategy is shown.

[0040] The table shows 3 clusters, C1 to C3, which are subject or not (Y / N) to beam formations B between the base station and the user equipment of the cluster because they are in the highly or moderately interfered category (Y) or weakly interfered (N). Those of the clusters which are subject to such beam formations are subject or not (Y / N), in addition and in accordance with the invention to a frequency foldback R, if they are in the highly interfered category. Those which are subject to such frequency foldback, because they are in the highly interfered category, or persistent interference, have their initial frequency band Fi replaced by a final band Ff, different from Fi. It can be identical for all the user equipment undergoing frequency foldback, and it is noted F2.

[0041] Thus, for the user equipment of cluster C1, there is neither beamforming nor frequency folding. For the equipment of cluster C2, there is beamforming, but no frequency folding, and for the equipment of clusters C3, C4 and C5, there is beamforming and frequency folding towards specific final bands for each user.

[0042] The method for identifying a fallback frequency band or sub-band for user equipment identified as having high interference, or persistent interference may be based on a frequency scan or an artificial intelligence learning method, with prediction of the fallback band from power spectral density measurement at the scale of all user equipment in the cluster for which frequency fallback is organized (cluster C3).

[0043] In [Fig.7], the implementation of the anti-jamming strategy, defined in [Fig.6], is represented. This is step E3 of implementing the strategy, in a simplified case with two clusters, a first cluster 100 and a second cluster 110, formed according to step El around a base station 10 communicating with user equipment 25 and targeted by a jammer 50 which creates a jamming zone 60.

[0044] The beams 90 are formed for all user equipment - one beam per user equipment, and the direction and opening of the beam are optimized - whether they are in cluster 100 or cluster 110, because cluster 100 has been evaluated as weakly jammed, and cluster 110 heavily jammed.

[0045] And simultaneously or quickly after, the frequency band associated with the user equipment 25 of the cluster 110 is modified, in this case moving from the frequency band F1 to the frequency band F2. On the other hand, the user equipment 25 of the cluster 100 all communicate with the base station 10 on the frequency band F1 as before the implementation of the anti-jamming process.

[0046] The following three technical means can be implemented in isolation or in combination.

[0047] 1) We activate the bandwidth parts BWPs (BandWitdh Parts in commun 5G cellular communication) on the fallback band, by RRC signaling (radio resource control).

[0048] 2) The scheduling controller (scheduler or scheduler) in charge is notified of the base station to restrict certain physical resource blocks, which have been identified as jammed.

[0049] 3) A carrier wave is aggregated by activating the selected frequency bands designated for fallback, assigned to the same user.

[0050] Then the beamforming parameters are optimized, namely the direction of the beams and their aperture or the pointing angle, to maximize the gain in transmission and reception by directional beams towards the area of ​​the user equipment concerned, to counter the jammer. This optimization is carried out by Artificial Intelligence, for example by Bayesian Optimization.

[0051] In addition, the interference from the jammer is rejected by sending zeros in its direction from the base station.

[0052] In an exemplary implementation, 400 user devices are distributed around 3 base stations each comprising three sectors with pointing directions to be configured. An omnidirectional jammer is present: some users are dissatisfied with the quality of the communication, but others are satisfied. Initially, 52.5% of the users are satisfied, then the orientations of the three antenna sectors are configured, and 73.5% of the users are satisfied. Then, the principles of the invention are engaged, and firstly, a beam reconfiguration is carried out for each of the three antenna sectors, and 85% of the users are satisfied, and finally, the frequency foldback is carried out, and 92.5% of the users are satisfied.

[0053] In [Fig.8], step E4 of allocating the antenna elements of the relay antenna 10 facing the jammer 50 is shown, creating a jamming zone 60.

[0054] The user equipment of the weakly jammed clusters is served primarily by a small number of antenna elements, represented by the panel 410, generating, due to their small number, continuous coverage over a wide area 91 (seen from the base station this is an angle or a wide solid angle), which makes it possible to maintain communication with numerous user equipment with few antenna resources, in this case a small number of antenna elements. And this, even though the user equipment concerned is relatively dispersed on the ground, the essential thing being that it is little impacted by the interference.

[0055] The heavily jammed user equipment is served, on the other hand, by directional beams 92, each dedicated to a limited number of user equipment grouped in a narrow zone (seen from the base station this is a narrow angle or solid angle), and requiring for its generation a high number of antenna elements, represented by the panel 420. The gain is higher due to the beam formation, which makes it possible to overcome the jamming.

[0056] The scheduling processor further chooses, among the user equipment and the associated beams to be served, those for which it can perform joint resource allocation (co-scheduling: coordinated scheduling) which is likely to improve spectral efficiency.

[0057] Thus, a multi-beam allocation is carried out (Multi User-MIMO technology) and we are then able to free up frequencies which can be reused for other purposes.

[0058] The invention applies to communication networks of the 4G or later cellular technology type, but also to tactical military communication networks.

Claims

Claims

1. Method for dynamically allocating resources for radio wave communication between a base station (10) of a communication network and user equipment (25), the method comprising, in response to a detection (E0) of interference between the base station (10) and one or more user equipment (25), a step of assigning (El) the user equipment (25) to at least two classes of user equipment depending at least on a level of impact of the detected interference on the communication between the respective user equipment and the base station, then, depending on the assignment, for the user equipment of at least one high interference class, changing (E3a) at least one frequency band or sub-band for their communication with the base station, for the user equipment of at least one non-high interference class,maintaining (E3b) essentially unchanged the frequency bands and sub-bands for their communication with the base station, as well as configuring (E3c) beams from the base station (10) to user equipment (25) at least some of which are in the non-high interference class.,

2. Resource allocation method according to claim 1, characterized in that the change (E3a) of at least one frequency band or sub-band is carried out towards at least one other band or sub-band, identified by power spectral density measurement, evaluated at the level of a set of user equipment.

3. A method of allocating resources according to claim 1 or claim 2, characterized in that the change (E3a) of at least one frequency band or sub-band comprises an activation of contiguous frequency blocks or an activation of frequency blocks for aggregation of a carrier, other frequency blocks possibly being deactivated.

4. A method of allocating resources according to one of claims 1 to 3, characterized in that the beam configuration (E3c) further comprises a beam modification for a user equipment of a high interference class after the change (E3a) of at least one frequency band or sub-band for the communication of said user equipment with the base station, to maximize the gain for an uplink or for a downlink to said equipment user.

5. Method for allocating resources according to one of claims 1 to 4, characterized in that the change (E3a) of at least one frequency band or sub-band comprises a determination of a jammed spectral band of a user equipment by analyzing the blocks of physical resources allocated by the scheduling processor.

6. Method for allocating resources according to one of claims 1 to 5, characterized in that the assignment (El) to the classes is also done by taking into account beamforming weights formed prior to the detection (E0) of interference between the user equipment and the base station.

7. Method for allocating resources according to one of claims 1 to 6, characterized in that the assignment (El) to the classes is further carried out using location information or positioning techniques.

8. Method for allocating resources according to one of claims 1 to 7, characterized in that, the network being a 4G or later cellular telephone network, the assignment (El) to the classes is done using information natively collected by the base station.

9. Method for allocating resources according to one of claims 1 to 8, characterized in that the method further comprises a configuration (E4) of beams, by implementing a massive MIMO antenna function, comprising for user equipment of the high interference class a coordinated scheduling of several spatially separated beams on the same time and frequency resources.

10. Method for allocating resources according to one of claims 1 to 9, characterized in that the method further comprises a configuration (E4) of beams which opens, by implementing a massive MIMO antenna function, more widely beams directed towards users of a low interference class than towards users of a high interference class.

Images