Method for generating beams for a radio communication antenna array and corresponding device

Abstract

Method for generating beams of a radio communication antenna array and corresponding device. The invention relates to a method for generating beams of a radio communication antenna array, a beam corresponding to a subdivision of a beam grid of the radio communication antenna array consisting of a given number of subdivisions, the method comprising the following steps: - determining an angular aperture of at least one beam of said beam grid as a function of a probability density of the presence of a user terminal to be served in the corresponding subdivision of said beam grid, - determining, as a function of the angular aperture of said at least one beam of said beam grid, modulation coefficients of a signal in amplitude and phase,- modulation of at least one signal processed by an antenna of the radio communication antenna array by means of said amplitude and phase modulation coefficients. FIGURE 5,

Description

Title of the invention: Method for generating beams of a radio communication antenna network and corresponding device Field of the invention

[0001] The field of the invention is that of radio communication antenna networks. More particularly, the invention relates to a method for modifying the beam opening of radio communication antenna networks. Prior art and its drawbacks

[0002] New mobile communication standards, such as the 5G standard, or fifth generation of standards for mobile telephony, propose using new radio frequency bands such as the millimeter frequency band which extends from 30 to 300 GHz.

[0003] The use of this millimeter frequency band makes it possible to meet the growing need for data exchange which is at the heart of the problems that the 5G standard seeks to resolve.

[0004] However, the millimeter frequency band has some disadvantages compared to historical frequency bands, such as higher free-space propagation losses and penetration losses. The use of radio communication antenna arrays makes it possible to compensate for free-space propagation losses through the implementation of energy focusing techniques.

[0005] A conventional technique consists of controlling the transmission or reception of a radio communication antenna array by means of an amplitude and / or phase modulation law applied to the signals (called electrical as opposed to the radio signal transmitted by an antenna) processed by the various antennas constituting the radio communication antenna array in order to focus the energy of the associated radio signal in a desired direction. Such a technique is commonly referred to as beamforming. A particularity of this technique is that the opening of the formed beam is inversely proportional to the size of the antenna array used for beamforming. Thus, the larger the radio communication antenna array, the narrower the beam and the greater the radiation gain in the direction of this beam.This feature can be a disadvantage when the direction favorable to the establishment of a communication link between, for example, a base station and a mobile terminal is not precisely known or when significant sectoral and stochastic attenuations occur.

[0006] Indeed, this increases the access time to the base station because many beams must be tested to cover the same area of ​​a cell served by the base station in order to identify the appropriate beam. There is therefore a need for a technique for generating beams of a radio communication antenna network that does not have all or part of the aforementioned drawbacks, particularly during the procedures for establishing a communication link between a base station and a mobile terminal. Statement of the invention

[0007] The invention meets this need by proposing a method for generating beams of a radio communication antenna array, a beam corresponding to a subdivision of a beam grid of the radio communication antenna array consisting of a given number of subdivisions, the method comprising the following steps: - determination of an angular opening of at least one beam of said beam grid as a function of a probability density of presence, in the corresponding subdivision of said beam grid, of a user terminal to be served, - determination, as a function of the angular opening of said at least one beam of said beam grid, of modulation coefficients of a signal in amplitude and in phase, - modulation of at least one signal feeding an antenna of the radio communication antenna network by means of said amplitude and phase modulation coefficients.

[0008] Determining the angular opening of the beams of the beam grid as a function of a probability density of the presence of a user terminal, such as for example a mobile terminal, makes it possible to adapt the radiation gain in the direction of each beam of the beam grid to the needs. More particularly, the opening of the beams of the beam grid is determined as a function of a probability density characterizing the angular position of the user terminal in a spherical coordinate system centered on the antenna array. By adjusting the angular opening of the beams of the beam grid, it is possible to ensure the same probability of selection of the different beams.

[0009] Indeed, it is advantageous to have beams with a low angular aperture and a high radiation gain to target an area where the probability density of presence of a user terminal is high and beams with a larger angular aperture and a low radiation gain to cover an area where the probability density of presence of a user terminal is low, because this makes it possible to serve the user terminals as best as possible.

[0010] Such a solution makes it possible to distribute the energy radiated by a network of radio communication antennas between the different beams in a useful and reasoned manner in order to improve the conditions for establishing communication between a mobile terminal and a base station.

[0011] Finally, such a solution adaptably responds to the latency / signal-to-noise ratio (SNR) compromise. In the case where the number of beams used is sufficient to avoid resorting to broadening techniques, the gain at transmission is maximum. However, the greater the number of beams, the greater the access time since the beams are time-multiplexed. The present solution therefore offers a compromise between the latency time linked to access to the cell and the signal-to-noise ratio (SNR).

[0012] According to a feature of the beam generation method, the latter further comprises a distribution of the constituent subdivisions of said beam grid as a function of a geometry of an area to be covered by the radio communication antenna array. More particularly, the geometry of an area to be covered by the radio communication antenna array is a function of a position and an orientation of the radio communication antenna array in an environment where the radio communication antenna array is located.

[0013] The cutting of the beam grid is adapted to the shape and orientation of the area to be covered by the antenna array as perceived by the antenna array. This shape depends on the position and orientation of the antenna array relative to the area to be covered.

[0014] Thus, the beams generated by the antenna array are oriented so that radiation reaches all points in the area to be covered by the antenna array, thus allowing a user terminal to be served wherever it is located in this area to be covered.

[0015] According to another feature of the beam generation method, the number of subdivisions constituting the beam grid is determined as a function of a value of a signal-to-noise ratio of the radio signals emitted by the antenna network and of a latency time for serving said user terminal.

[0016] This makes it possible to ensure that each beam has a radiation gain adapted to the need by finding a compromise between a value of a signal-to-noise ratio and a value of an access latency time to a cell served by a base station comprising the antenna network considered. Indeed, it is possible to evaluate the gain associated with each direction (6. <p) du repère de coordonnées sphériques centré sur le réseau d’antennes en fonction du nombre de faisceaux utilisés et également le temps de latence pour servir ledit terminal utilisateur puisque les signaux d’accès à la cellule sont émis sur des symboles OFDM bien spécifiés dans les textes normatifs relatifs à la fifth generation of radio communication currently being specified.

[0017] Finally, according to a last particularity of the beam generation method, the modulation coefficients of a signal in amplitude and in phase are obtained by applying a Fourier transformation to the radiation emitted by at least one network of radio communication antennas.

[0018] The invention also relates to a device configured to generate beams, a beam corresponding to a subdivision of a beam grid of a radio communication antenna network consisting of a given number of subdivisions, the device comprising means for: - determining an angular opening of at least one beam of said beam grid as a function of a probability density of presence of a user terminal to be served in the corresponding subdivision of said beam grid, - determining, as a function of the angular aperture of said at least one beam of said beam grid, modulation coefficients of a signal in amplitude and in phase, - interface with means for modulating at least one signal feeding an antenna of the radio communication antenna network by means of said amplitude and phase modulation coefficients.

[0019] The invention also relates to a radio communication antenna network adapted to interface with at least one device configured to generate beams, a beam corresponding to a subdivision of a beam grid of the radio communication antenna network consisting of a given number of subdivisions, the antenna network comprising means for: - modulate at least one signal to feed an antenna of the radio communication antenna network by means of amplitude and phase modulation coefficients determined by the device.

[0020] The invention finally relates to a computer program product comprising program code instructions for implementing a method as described above, when executed by a processor.

[0021] The invention also relates to a recording medium readable by a computer on which is recorded a computer program comprising program code instructions for executing the steps of the method according to the invention as described above.

[0022] Such a recording medium may be any entity or device capable of storing the program. For example, the medium may comprise a storage means, such as a ROM, for example a CD ROM or a microelectronic circuit ROM, or a magnetic recording means, for example a USB key or a hard disk.

[0023] On the other hand, such a recording medium may be a transmissible medium such as an electrical or optical signal, which may be conveyed via an electrical or optical cable, by radio or by other means, so that the computer program it contains is remotely executable. The program according to the invention may in particular be downloaded over a network, for example the Internet.

[0024] Alternatively, the recording medium may be an integrated circuit in which the program is incorporated, the circuit being adapted to execute or to be used in the execution of the method which is the subject of the aforementioned invention. List of figures

[0025] Other aims, characteristics and advantages of the invention will appear more clearly on reading the following description, given as a simple illustrative, and non-limiting, example, in relation to the figures, among which:

[0026] [Fig-1]: this figure represents the steps of a method of generating at least one beam of a radio communication antenna network according to one embodiment of the invention,

[0027] [Fig.2]: this figure represents an antenna network in position in its environment ronment,

[0028] [Fig.3]: this figure represents the rotation carried out in order to move from a global reference frame to a spherical reference frame centered on the antenna network,

[0029] [Fig.4]: this figure represents the possible positions of user equipment in a spherical reference frame centered on the antenna array,

[0030] [Fig.5]: this figure represents a gain provided by the RA antenna network for each beam,

[0031] [Fig.6]: this figure represents a distribution of a radiation gain as a function of the nature of the cutting, uniform or not, of the beam grid,

[0032] [Fig.7]: this figure represents a grid of beams cut in such a way uniform,

[0033] [Fig.8]: this figure represents a device capable of implementing the beam generation method,

[0034] [Fig.9]: this figure represents the device of [Fig.8] connected to a modulator of phase and amplitude modulator of an antenna in the antenna array.

[0035] Detailed description of embodiments of the invention

[0036] The general principle of the invention is based on the determination of the angular opening of the beams of the beam grid as a function of a probability density of presence of a user terminal, such as for example a mobile terminal, which makes it possible to adapt the radiation gain in the direction of each beam of the beam grid to the needs. More particularly, the opening of the beams of the beam grid is determined as a function of a probability density characterizing

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[0043] the angular position of the user terminal in a spherical coordinate system centered on the antenna array. By varying the angular aperture of the beams in the beam grid, it is possible to ensure the same probability of selection of the different beams. Indeed, it is interesting to have beams with a low angular aperture and a high radiation gain in an area where the probability density of the presence of a user terminal is high and beams with a larger angular aperture and a low radiation gain in an area where the probability density of the presence of a user terminal is low, because this makes it possible to serve the user terminals as best as possible. We now present, in relation to [Fig.l], the steps of the method for generating at least one beam of a radio communication antenna network. The first step El of the beam generation method consists of defining the position 1 xvz ] of the antenna array RA in a global reference frame RG. Such an global reference frame RG is a Cartesian reference frame. For example, the antenna array RA shown in [Fig.2] is positioned in the global reference frame RG such that ( Xant, y,inf Zant ) = ( 50, 50, 10) • The orientation ( a, [3, Y) of the antenna array RA relative to the global reference frame RG is also determined. In the example shown in Figure 2, the antenna array RA is oriented such that ( 0(, P, y) = ( 225 ° , 45 °, 0° ). Such an orientation is represented in [Fig.3] by the axes (x, y, z). During a step E2, a presence probability density law characterizing a position of the user equipment UE to be served in an area to be covered ZC by the antenna network RA is determined in the global reference frame RG. When, as in [Fig.2], the area to be covered ZC by the antenna network RA corresponds to a room such as for example a storage space where the movements of robots equipped with user equipment UE are constrained and where the tasks performed are known, such a presence probability density law is obtained in a simple manner. When a user equipment is located outdoors and / or performs unconstrained movements, such a presence probability density law may be more complex to determine. In the remainder of the document, it is considered that the position of the user equipment UE is random along the x and y axes of the global reference frame, but constant along the z axis of this same general reference frame RG. In other words, in this exemplary embodiment, the user equipment UE moves at a given height Zo = k with k Æ R+). Two independent random variables X and Y are then introduced, characterizing a position of the user equipment UE to be served in the global reference frame RG, defined

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[0053] such as XG [xinin, Xmax] and y G [yy ]' these two intervals defining the rmin' AnaxJ limit coordinates of the part of the area to be covered ZC by the antenna network RA in which the user equipment UE moves. The variables X and Y are respectively associated with the following functions fx(x) and fY(y) representing a probability density of presence of the user equipment UE in the reference frame RG such that: fxmax Amax The variable Zo = k with k -G R+ is also introduced. During a step E3, a position (x', y', z') of the user equipment UE expressed in an RRA frame centered on the RA antenna array is obtained in ef performing a translation then a rotation: F! * X Y .Z'. X-xantl (1) where X, Y and Z' are random variables characterizing a position of the equipment UE user to be served in the Cartesian RRA reference frame associated with the RA antenna network, and where R1 is the rotation matrix expressed as: cosacosp cosasinpsiny- sinacosy \ cosasinpcosy + sinasiny sinacosp sinasinpsiny + cosacosy sinasinpcosy - cosasiny -sinp (2) cospsiny cospcosy / In a step E4, a position (x', y', z') of the user equipment UE is expressed in an RSRA frame in spherical coordinates (p', 0', <p' ). Un tel repère RSRA in spherical coordinates is centered on the RA antenna array. In such a RSRA frame in spherical coordinates, the position (x', y', z') of the user equipment UE is then given by: 0 -arccos^T <[) = atan2(Y, X) where P , 0 and <p sont des variables aléatoires définissant la position de l’équipement utilisateur UE dans le repère RSRA en coordonnées sphériques associé au réseau d’antennes RA. In [Fig.4], the spherical coordinates (0', tp') of the user equipment UE are represented for 1,000,000 possible positions with the assumption ( Xanb Zant ) = ( 50, 50, 10 ) and' ( Y ) = ( 225 0 , 45 0 , 0 ° ) • In this

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[0070] example, the random variables X and Y previously defined follow laws fx(x), fy(y), uniform probability density of presence in the Cartesian reference frame RG: f ü _ f V (xmax _ \nin), X^^ Xmax ] (4) 1— 1 \ / i 0 otherwise £ I \ H / fy -y A yc[y ■ ,y ] fy y = I max min ' LJ min J max J \ / i 0 otherwise °ù xmin ~ — 4 and Xmax — y = 48 in the chosen example. In [Fig.4], we see that the area to be covered ZC by the antenna array RA is divided by means of a grid G ​​consisting of a plurality of subdivisions SDnbbeam. The grid G ​​is a grid of beams of the antenna array RA. Each subdivision SDnbbeam of the grid G ​​corresponds to a beam of the antenna array RA. Knowing the number nbbeam of subdivisions of the grid G ​​and therefore the number of beams that the antenna network RA must generate, we determine, during a step E5, the distribution of the subdivisions SDnbbeam constituting the grid according to the directions ô' and <p'du repère sphérique RSRA. Let nbi^a^y and 0 be the number of beams in the y and 0 directions of the spherical frame RSRA respectively, then we have: nbteam = nb^ Y x nbbeam 0 (6) with ^'max \iiin _____ n^beaiRY (7) SœaxAnm n^team. a' From equations (6) and (7), we obtain: (g) Uübeam, 8 ~ VV -YX V 'max The value / n~~4~ ' is then rounded to the nearest divisor of fiblx,aril of f ÏIWA îïîlïï < y -«A Uÿ 77 x llübeam way to get nbteam e. It follows: nK — (9) U^m,Y nbheanU) In the example described with reference to figure 4, nbiX:am is 32 which gives: ^beam, 9 ■»' -y A ,lvbeam 32 "475 45.7-(-45.7) “ ' Thus, the grid G ​​includes 32 subdivisions distributed as follows: 4 subdivisions along the 0 axis and 8 subdivisions along the y' axis, since 0 = 4 and consequently nb[^Mn y — 8. During a step E6, the size of each subdivision SDnbbeam of the grid G ​​is determined so that each subdivision SDnbbeam contains the same number possible positions of the user equipment UE. Thus, the probability of selection of each SDnbbeam subdivision, and therefore of each beam, is almost uniform.

[0071] Determining the size of each subdivision SDnbbeam of the grid G ​​amounts to determining the angular aperture of the corresponding beam. Consequently, the higher the angular presence probability density of the user equipment UE for a given subdivision SDnbbeam, the lower the angular aperture of the corresponding beam. Conversely, the lower the angular presence probability density of the user equipment UE for a given subdivision SDnbbeam, the higher the angular aperture of the corresponding beam. In the general reference frame RG, which is a Cartesian reference frame, the present method results in a degradation of the power received from the sectors of the area to be covered ZC associated with a low angular probability density in favor of a majority of them.

[0072] Thus, knowing that each point corresponding to a possible position of the user terminal UE is associated, in the RSRA reference frame, with a value in elevation 0 and in azimuth y', an algorithm defines the division of the different subdivisions SDnbbeam of the grid G ​​according to the following implementation example.

[0073] In a step E6i, the points are sorted according to their associated azimuthal value y' such that:

[0074] - each point belongs to exactly 1 azimuthal zone

[0075] - each azimuthal zone contains the same number of points to within 1 point (in the case where the number of points is not a multiple of y): 100761 - Vmi„ (' ) s Ymax (i) s V„,in (i +1) s V„x (i + 1) for all i G [1, v- 1]

[0077] In a step E62, for each azimuthal zone defined in step E61, the points are then sorted according to their elevation value 9 such that:

[0078] - each point belongs to exactly 1 elevation zone

[0079] - each zone contains the same number of points to within 1 point (in the case where the number of points is not a multiple of:

[0080] -0min(j) < 0^( j) <emm(j+l) <0max(j+l) pour tout je [ 1, nbbeam e -1]

[0081] Dans une étape E63, on obtient alors nbteam X nbi,eim y sous-groupes de points ( i, j ). Les bornes de la subdivision SDnbbeam correspondant à chaque sous-groupe ( i, j ) sont déterminées par y^ ( i ), y^ ( i), 0min( j ) et 0max ( j ) • Les minimums y' . (i), 0' ;n(i) et les maximums Y’ G) A ( j) n'appartiennent pas néces-sairement au même point.

[0082] The determination of the amplitude and phase modulation coefficients that each antenna in the antenna array applies to a signal that it processes to form each beam consists of calculating Fourier coefficients for a network linear oriented along Tet for a linear network oriented along y.

[0083] As a reminder, the radiation AF( tp ) produced by a linear array of antennas composed of 2K antennas is given by the following formula:

[0084] AF( = + ( | ())

[0085] with

[0086] kodzms'(O')' [0, tt] (z-oriented network} [ ) «» (y'), y -<= [ - ?, * ] (11)

[0087] And where k0 = 2tt / Xo corresponds to the wave number.

[0088] The corresponding Fourier coefficients are then obtained by applying the following formulas: y'-oriented network

[0089] rT / 2 4hT / 2AF(40e-^2k^ -K <k< -1 rT / 2 IJ.^AFCipM^- 1 ) / 2 ] 1 < k< K (12)

[0090] where T corresponds to a period of the AF radiation ( tp ). Here, the AF radiation ( tp ) is defined via the rect function since the beams are of rec shape tangular as can be seen in [Fig.4], so we obtain:

[0091] 1 mæU ■ ,*p ] (13) AF(l])) = | ' [¥i™ nnaxj 0 otherwise

[0092] For a linear network oriented along y, the width of the desired radiation AF ( tp ) along the direction Q having been determined during step E6 for each beam making up the grid G, we then have for a given beam:

[0093] = kot^a^0b mm) (14)

[0094] = ktflz cos (ebmax) (15)

[0095] where and define the angular range in elevation for which the power is emitted for a given beam, and dz represents the spacing between the antennas making up the antenna array RA. Knowing that the antenna array RA comprises in the chosen example 4NM antennas where N and M are even numbers, in the case where dz = Xo / 2. we obtain:

[0096] |d_j^AF( [ ÎTAF(tp)ej[(2m-1) / 2]^{ / 7,

[0097] and therefore

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[0105] am _L^ej[(2mX) / 2]y.n_^^ (17) j(2m+l)7X 7 j(2m-l)7î f X[ ( 2m-l) / 2]ip . t C JL ' ' min W<), l <m<M Thus, after applying a Fourier transform during a step E7, we obtain an excitation vector for the antenna network RA in the direction z' of the following form: am ~ [ / Et' / ' » aP ^1' • • • ' aM-Ÿ üm\ ($1) For a linear network oriented along y, the width of the desired radiation AF ( tp ) along y having been determined during step E6 for each beam making up the grid G, we then have for a given beam: b_min b_max where and yb define the angular range in azimuth for which the power is emitted for a given beam. Knowing that the antenna array RA comprises in the chosen example 4NM antennas where N and M are even numbers, in the case where dy = Àq / 2, we obtain: .Ttsinf 1 _____________1 27rsin(^^ AF ( tp) e~j[ (2n+l) / 2]ipJ^ _____________1 . x, ,„..X zîtsm —— —--— _.. AF( ip)ed( (2^^ / 2(^ / ^, 1 £ n SN

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[0110] [YES] (21) and so an — j(2n+l)œin(^ (ej[(2n+I) / 2]M>m.ii_e-j[(2^+1) / 2]^^ -N <n< _ 1 -------î_---;_ Xj[(2n4) / 2]ynin_eq[(2^ l <n<N j(2n-l)7rsin(^^) Thus, after applying a Fourier transform during a step E8, 22 we thus obtains an excitation vector for the antenna network RA in the direction y' of the following form: an ~ [ 4-N' • • •, a-]> ab • ■ ■ » aN-b aN] Finally, the excitation vector b to be applied to the antenna array RA for forming a beam of the grid G ​​is expressed as follows: a-(Ml)an> •••• 3 a[an» •••< aM-lan' aMan ] (24)

[0112] Which gives:

[0113] b - [bM-Nï • ••, bb_(M_]).N, b_(M_j)iN, .... bM.N, ..., bMN ] (25)

[0114] Where

[0115] bm,n — (26)

[0116] Thus, the number of vectors b to be calculated depends directly on the number of beams nbbeam making up the grid G.

[0117] During a step E9, each antenna constituting the antenna array RA modulates a signal in amplitude and in phase from the vector b. The excitation coefficients bm.n of the vector b can be rewritten in an exponential form which makes it possible to dissociate the amplitude control Am„ from the phase control «bmji:

[0118] bn^A^-e?)

[0119] with

[0120] A„yi=\blfVi\ (28)

[0121] and

[0122] Om.n = arg(bm.n) (29)

[0123] where Am,n and d>m,n correspond respectively to a command at the level of an amplifier and at the level of a phase shifter for the mth antenna of the antenna network RA according to 7 and the nth antenna according to 7 / . y

[0124] As an example, the excitation vector b is calculated for each beam of the beam grid G ​​and is applied by the constituent antennas of the antenna array RA in order to generate the beams corresponding to the beam grid G. The gain provided by the antenna array RA for each beam is shown in [Fig. 5]. In this [Fig. 5], the subdivisions SDnbbeam presenting the largest surfaces are those having the lowest gain. They correspond to the regions of the area to be covered ZC by the antenna array in which the angular presence probability density of the user equipment UE is the lowest.

[0125] As shown in [Fig.6], it appears that the previously described method results in an improvement in the overall gain of an RA antenna array for two main reasons: • The gain is degraded for some SDnbbeam subdivisions of the beam grid G ​​in favor of a majority of them, • Each beam covers a subdivision SDnbbeam where the user equipment UE is potentially present unlike solutions in which the beam grid G ​​is cut uniformly as shown in [Fig.7].

[0126] Indeed, still with reference to [Fig.6], it appears that in approximately 90% of cases, i.e. for 90% of the positions of the user equipment UE in the area to cover ZC by the antenna array RA, the method proposed in the present application is superior to a solution in which the beam grid G ​​is cut uniformly.

[0127] [Fig.8] represents a device 10 capable of implementing the beam generation method according to [Fig.l].

[0128] A device 10 may comprise at least one hardware processor 11, a storage unit 12, and at least one network interface 13 which are connected to each other through a bus 14. Of course, the constituent elements of the device 10 may be connected by means of a connection other than a bus.

[0129] The processor 11 controls the operations of the device. The storage unit 12 stores at least one program for implementing the method according to an embodiment to be executed by the processor 11, and various data, such as parameters used for calculations performed by the processor 11, intermediate data of calculations performed by the processor 11, etc. The processor 11 may be formed by any known and suitable hardware or software, or by a combination of hardware and software. For example, the processor 11 may be formed by dedicated hardware such as a processing circuit, or by a programmable processing unit such as a central processing unit (Central Processing Unit) which executes a program stored in a memory thereof.

[0130] The storage unit 12 may be formed by any suitable means capable of storing the program(s) and data in a computer-readable manner. Examples of the storage unit 12 include non-transitory computer-readable storage media such as semiconductor memory devices, and magnetic, optical, or magneto-optical recording media loaded into a read-write unit.

[0131] At least one network interface 13 provides a connection between the device 10 and a phase modulator of a signal connected to an antenna of the antenna array.

[0132] [Fig.9] represents the device 10 connected to a phase modulator MP and an amplitude modulator MA of an antenna of the antenna array. The phase modulator MP and the amplitude modulator MA are also connected to a radiofrequency chain CRF whose role is to convert the signal after baseband processing into a useful transposed signal, amplified and transposed into frequency SRF. The phase modulator MP and amplitude modulator MA then provide a modulated radio signal SRF((Pn), the value of the phase shift applied having been calculated according to the method previously described.

Claims

Claims

1. Method for generating beams of a radio communication antenna array, a beam corresponding to a subdivision of a beam grid of the radio communication antenna array consisting of a given number of subdivisions, the method comprising the following steps: - determining an angular aperture of at least one beam of said beam grid as a function of a probability density of presence, in the corresponding subdivision of said beam grid, of a user terminal to be served, - determining, as a function of the angular aperture of said at least one beam of said beam grid, modulation coefficients of a signal in amplitude and in phase, - modulating at least one signal feeding an antenna of the radio communication antenna array by means of said amplitude and in phase modulation coefficients.

2. A method of generating beams of a radio communication antenna array according to claim 1, further comprising a step of distributing the constituent subdivisions of said beam grid according to a geometry of an area to be covered by the radio communication antenna array.

3. A method of generating beams of a radio communication antenna array according to claim 2, wherein the geometry of an area to be covered by the radio communication antenna array is a function of a position and an orientation of the radio communication antenna array in an environment where the radio communication antenna array is located.

4. A method of generating beams of a radio communication antenna array according to claim 1, wherein the number of subdivisions constituting the beam grid is determined as a function of a value of a signal-to-noise ratio of the radio signals transmitted by the antenna array and a latency time for serving said user terminal.

5. A method of generating beams of a radio communication antenna array according to claim 1, wherein the modulation coefficients of a signal in amplitude and phase are obtained by applying a Fourier transformation to the radiation emitted by at least one of the antennas. at least one network of radio communication antennas.

6. Device configured to generate beams, a beam corresponding to a subdivision of a beam grid of a radio communication antenna network consisting of a given number of subdivisions, the device comprising means for: - determining an angular opening of at least one beam of said beam grid as a function of a probability density of presence of a user terminal to be served in the corresponding subdivision of said beam grid, - determining, as a function of the angular opening of said at least one beam of said beam grid, modulation coefficients of a signal in amplitude and in phase, - interfacing with means for modulating at least one signal feeding an antenna of the radio communication antenna network.

7. Radio communication antenna array adapted to interface with at least one device according to claim 6 configured to generate beams, a beam corresponding to a subdivision of a beam grid of the radio communication antenna array consisting of a given number of subdivisions, the antenna array comprising means for: - modulating at least one signal to feed an antenna of the radio communication antenna array by means of amplitude and phase modulation coefficients determined by the device.

8. A computer program product comprising program code instructions for implementing a method of generating beams of a radio communication antenna array according to claim 1, when executed by a processor.

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