JP2019071644A - Beam forming using antenna arrangement - Google Patents

Abstract

To provide a mechanism for beam forming using an antenna array including two polarization elements.SOLUTION: Beam forming using an antenna device includes generating one or two beam ports (S102) and is defined by combining at least two non-overlapping subarrays. Each subarray has two subarray ports, and the two subarray ports have the same power pattern and mutually orthogonal polarization. The at least two non-overlapping subarrays are combined via expansion weights. The expansion weights map one or two beam ports to the subarray ports such that the one or two beam ports have the same power pattern as the subarray. At least some of the expansion weights have the same non-zero magnitude and are associated with a phase that forms a transmit lobe and transmit signals using the one or two beam ports (S104).SELECTED DRAWING: Figure 14

Description

  Embodiments presented herein relate to beamforming, and in particular to methods for beamforming using antenna arrays with dual polarization elements, antenna arrays, and computer programs.

  In a communication network, there may be challenges in obtaining good performance and capacity in a given communication protocol, its parameters, and the physical environment in which the communication network is utilized.

  One component of a wireless communication network that may be difficult to obtain good performance and capacity is configured for wireless communication with another network node and / or with a wireless user terminal It is an antenna of a network node.

  For example, massive beamforming, ie beamforming using active antenna arrays with many more antenna elements than those used in current communication networks, will be in the wireless access part of future fifth generation (5G) communication networks It is expected to be a technical component. By using a large antenna array at the radio base station, user data can be transmitted in a concentrated manner in space, resulting in the reception of energy mainly by wireless devices dedicated to user data, and so on There is little or no interference perceived by wireless devices or other types of nodes. Thus, massive beamforming has the potential to increase the system capacity and energy efficiency by orders of magnitude.

  One potential problem with massive beamforming may be related to the fact that the beam is narrow so that it may only be able to receive data with a dedicated wireless device. While this is desirable for user data, some data, such as system information, for example, preferably needs to be transmitted (i.e., broadcast) to all or at least most of the wireless devices in the communication network. Thus, such data must be transmitted with wide coverage to reach all wireless devices. The following outlines some of the ways in which this problem is addressed. However, as also stated, each of these schemes has drawbacks.

  According to a first approach, separate wide beam antennas may be used to transmit broadcast data. The disadvantage of this approach is that it requires additional hardware.

  According to a second approach, broadcast data is transmitted using a single antenna array element or sub-array of antennas. This array element or sub-array has a wider beam than the full array of antennas. The disadvantage of this approach is that only one or a few power amplifiers (PAs) in the antenna array are utilized, thus wasting power resources.

  According to a third approach, amplitude and / or phase tapering is used to spread the beam across the full array of antennas. The disadvantage of such tapering is that amplitude tapering reduces the utilization of PA resources, and in many cases it is not possible to use phase-only tapering to synthesize the desired beam shape It is.

  According to a fourth approach, narrow beams are used to transmit broadcast data sequentially in various directions. A potential disadvantage of this approach is that it takes longer and consumes more resource elements than transmitting broadcast data simultaneously in all directions with wide beams.

  Another situation where it may be desirable to use a wide beam in an antenna array with many elements is in millimeter wave (mmW) communication, which is an access technology that is expected to be part of 5G wireless access. As propagation losses increase at such high frequencies, in some cases both the receiver and the transmitter may require high gain beamforming to maintain the link budget. Typically, beamforming may be required because the main propagation path between the transmitter and receiver is not known in advance. It may take a great deal of time / frequency resources to test all combinations of multiple narrow transmit and receive beams to find the best beam pair. The solution to this problem may be to have the radio base station start the search procedure with a wide beam and then gradually narrow this beam until the best pair of narrow beams is found. Such beam search procedures generally require a means for generating beams with different beam widths in a flexible manner. When it is desirable to use all antenna elements and all PAs at full power when transmitting beams with different beam widths to fully utilize the antenna array and available PA resources There is.

  Thus, there is a need for improved beamforming.

  The purpose of the embodiments herein is to achieve efficient beamforming.

  According to a first aspect, a method is presented for beamforming using an antenna array comprising two polarization elements. The method comprises generating one or two beam ports, the one or two beam ports being defined by combining at least two non-overlapping sub-arrays. Each subarray has two subarray ports, and the two subarray ports have the same power pattern and mutually orthogonal polarizations. The at least two subarrays that do not overlap are combined via the expansion weights. The extension weights map the one or two beam ports to the sub-array port such that one or two beam ports have the same power pattern as the sub-array. At least some of the extension weights have the same non-zero magnitude and are associated with phases that form a transmit lobe. The method includes transmitting a signal using the one or two beam ports.

  Advantageously, this provides for efficient beamforming.

  Advantageously, this implements an antenna architecture and method for creating one or two beam ports with adjustable beam width.

  The one or two beam ports have the same power radiation pattern and orthogonal polarization in any direction.

  The beam width at this one or two beam ports can be very wide compared to the array size, and can be as wide as in the single element case.

  All power amplifiers of the antenna array can be used completely, ie with only the phase taper applied, by their respective beam port or a combination of two beam ports.

  The antenna architecture may be based on either a linear (1-D) antenna array or a planar (2-D) antenna array.

  According to a second aspect, an antenna device comprising an antenna array is presented. The antenna array comprises two polarization elements for beam forming. The antenna array further comprises a processing unit. The processing unit is configured such that the antenna array produces one or two beam ports, which are defined by combining at least two non-overlapping sub-arrays. Each subarray has two subarray ports, and the two subarray ports have the same power pattern and mutually orthogonal polarizations. The at least two subarrays that do not overlap are combined via the expansion weights. The extension weights map the one or two beam ports to the sub-array port such that one or two beam ports have the same power pattern as the sub-array. At least some of the extension weights have the same non-zero amplitude and are associated with the phase forming the transmit lobe. The processing unit is configured to allow the antenna array to transmit signals using this one or two beam ports.

  A network node comprising an antenna arrangement according to the second aspect is also presented.

  A wireless device comprising an antenna device according to the second aspect is also presented.

  According to a third aspect, a computer program for beamforming using an antenna array comprising two polarization elements is presented, the computer program comprising, when executed on a processing unit, the antenna array comprises a first And computer program code that enables the method according to the aspect to be performed.

  According to a fourth aspect, there is presented a computer program product according to the third aspect and a computer program product comprising computer readable means on which the computer program is stored.

  It should be noted that any of the features of the first, second, third and fourth aspects may apply to any other aspect where appropriate. Similarly, any advantages of the first aspect may equally apply to each of the second, third and / or fourth aspects, and vice versa. Other objects, features, and advantages of the described embodiments will be apparent from the following detailed disclosure, the appended dependent claims, and the drawings.

  In general, all terms used in the claims should be construed in accordance with their ordinary meaning in the art unless explicitly stated otherwise herein. All references to "a / an / the (elements, devices, components, means, steps, etc.)" refer to this element, device, component, means, step, etc., unless expressly stated otherwise. It should be interpreted in a non-limiting manner as referring to at least one of them. The steps of any of the methods disclosed herein may not be performed in the order in which they are disclosed, unless explicitly stated.

  Next, the concept of the present invention will be described by way of example with reference to the accompanying drawings.

FIG. 5 is a schematic diagram illustrating aspects of an antenna array according to an embodiment. FIG. 5 is a schematic diagram illustrating aspects of an antenna array according to an embodiment. FIG. 5 is a schematic diagram illustrating aspects of an antenna array according to an embodiment. Fig. 5 schematically shows an example of a sub array. FIG. 5 is a schematic diagram illustrating aspects of an antenna array according to an embodiment. Fig. 2 schematically illustrates an example of port expansion; Fig. 2 schematically illustrates a recursive port expansion; It is a figure which shows port mapping roughly. FIG. 5 is a block diagram showing functional units of the antenna device according to one embodiment. FIG. 5 is a block diagram showing functional modules of the antenna device according to one embodiment. It is a figure showing roughly a network node provided with an antenna device by each embodiment. It is a figure showing roughly the wireless apparatus provided with the antenna device by each embodiment. FIG. 1 schematically illustrates a computer program product according to one embodiment. 3 is a flow diagram of a method according to one embodiment. FIG. 7 illustrates simulation results of an example of a transmit lobe at a first beam port according to one embodiment. FIG. 7 illustrates simulation results of an example of a transmit lobe at a second beam port according to one embodiment. FIG. 5 illustrates simulation results of prior art beamforming using pure amplitude tapers for each polarization. FIG. 5 illustrates simulation results of prior art beamforming using pure phase tapers for each polarization. FIG. 7 shows simulation results of beam formation according to one embodiment.

  The inventive concept will now be described more fully hereinafter with reference to the accompanying drawings in which some embodiments of the inventive concept are shown. However, the inventive concept may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein, but rather, this disclosure is complete and complete. These embodiments are provided as an example so as to fully convey the scope of the inventive concept to a person skilled in the art. Like numbers refer to like elements throughout the description. Any steps or features shown in dashed lines should be considered optional.

  Various schemes have been proposed to generate a wide beam from a large two polarization array. As an example, a beam forming network, for example a Butler matrix, is applied to each polarization direction of the antenna array, and then a signal is transmitted using a beam with alternating polarization, using adjacent beams having the same polarization. Unwanted coherent addition of the transmitted signal may be avoided. The resulting beam pattern is usually pronounced, for example on the order of several dB. FIG. 17 shows an example of a broad beam pattern formed by conventional single polarization beamforming (SPBF), where weights are applied for each polarization and again desired for each polarization. The beam pattern is shaped, and many weighting factors will have amplitudes set to zero, thus reducing the utilization of power resources. This may be regarded as the extreme case of the amplitude taper. Another example involves applying an amplitude taper, which may also be regarded as providing satisfactory results in that it produces the desired beam shape, but using power resources for transmission It can not be regarded as providing satisfactory results in terms of rates. In many cases, using only the phase taper results in a pattern that does not meet the desired characteristics but that the utilization of power resources is satisfactory. The range of beam widths that can be obtained is also often limited. FIG. 18 shows an example of a broad beam pattern formed by conventional (SPBF) beamforming but limited to phase taper only for good power resource utilization. As a result, the beam pattern exhibits unwanted ripple.

  The antenna arrays and methods proposed herein achieve both beam patterns having the desired beam shape, as well as excellent power utilization. The embodiments disclosed herein relate specifically to efficient beamforming. Here, to obtain efficient beamforming, an antenna array, a method implemented by this antenna array, enabling the antenna array to perform this method when executed on a processing unit, for example in the form of a computer program product A computer program is provided that includes code for

  FIG. 1 is a schematic block diagram showing an exemplary architecture of a two-dimensional antenna array 1 to which the embodiments presented herein can be applied. However, the embodiments presented herein are equally applicable to one-dimensional antenna arrays. Thus, the antenna array 1 can be either a linear array (1-D), a uniform linear array (ULA), or a planar array (2-D), a uniform rectangular array (URA).

  The antenna front end comprises an array 1e of antenna elements, in which each antenna element is a subarray of several radiating antenna elements connected via feed networks to two subarray ports with orthogonal polarization. May be. Each sub array port is connected to a wireless chain included in the wireless array 1 d. The number of sub-array ports in block 1b accessible from baseband signal processing may be reduced via port reduction block 1c creating a new antenna port which is a (linear) combination of input antenna ports. If dedicated data and broadcast data are both sent simultaneously, access the sub-array port at baseband. Further, broadly speaking, access to all sub-array ports may be required to shape a broad beam in accordance with the beamforming scheme disclosed herein. In the baseband signal processing block 1a, virtual antenna ports can be created by matrix multiplication. These virtual antenna ports may be of different types. For example, in LTE, these virtual antenna ports may be common reference signal (CRS) at ports 0-3, channel state information reference signal (CSI-RS) at ports 15-22, and at ports 7-14. UE specific reference signals and data may be carried for the radio base station. Depending on the implementation, one or several blocks of the two-dimensional antenna array 1 in FIG. 1 may be removed.

  FIG. 2 is a schematic block diagram showing a possible implementation of the two-dimensional antenna array 1 of FIG. This implementation comprises a beamformer comprising the blocks 1a, 1b, 1c of FIG. 1, a radio array 1d and a physical antenna array 1e. In the example of FIG. 2, there are two antenna ports per sub-array. The beamformers 1a-c are configured to receive user data and control data, beamforming weights for user data, beamforming weights for reference signals such as CSI-RS, and beamforming weights for wide beam transmission. Ru. Each antenna element comprises two sub-elements 31, 32 with orthogonal polarization in all directions (of interest). Usually, these two subelements 31, 32 are arranged at the same position as shown in FIG. 3 (a), but may be arranged mutually offset as shown in FIG. 3 (b).

  The antenna array 1 is set to generate one or two beam ports, which are defined by combining at least two non-overlapping sub-arrays. As can be understood by one skilled in the art, the antenna array 1 may be configured to generate additional ports defined for various transmissions. Each subarray has two subarray ports, and the two subarray ports have the same power pattern and mutually orthogonal polarizations. The at least two subarrays that do not overlap are combined via the expansion weights. The extension weights map the one or two beam ports to the sub-array port such that one or two beam ports have the same power pattern as the sub-array. At least some of the extension weights have the same non-zero magnitude and are associated with phases that form a transmit lobe. The antenna array 1 is configured to transmit signals using one or two beam ports. As can be appreciated by one skilled in the art, the antenna array 1 may be configured to transmit additional signals using the same or additional beam ports.

  Next, embodiments will be disclosed that relate to further details of beam forming using the antenna array 1.

  Broadly speaking, the extension weights describe how one or two beam ports formed with a single set of sub-arrays can be mapped onto multiple sets of sub-arrays. Thus, according to one embodiment, the extension weights map the one or two beam ports to the sub-array port such that one or two beam ports have the same power pattern as the sub-array, and When ports are present, the two beam ports have mutually orthogonal polarizations in any direction.

  There may be various schemes for determining at least two non-overlapping sub-arrays and combining the at least two non-overlapping sub-arrays via the extension weights. Next, various embodiments related to this will be further described.

  In general terms, to generate one or two beam ports that provide the desired beam width and to use the entire antenna array for good utilization of power resources, sub-arrays for one or two beam ports It may be necessary to determine port mapping and to extend the sub-array mapping to the entire antenna array.

  In sub-array port mapping, sub-arrays are determined such that the desired beam width or even beam shape is achieved with the best possible power utilization. The power utilization after expansion of each subarray is the same as that of the subarray. In FIG. 4, four examples of antenna arrays 1e each comprising two subarrays 41, 42 are shown schematically in (a), (b), (c) and (d), each antenna array 1e comprises two beam ports 43, 44 respectively.

To extend sub-array mapping to the entire antenna array, using the extension weights based on powers of 2, 6, and 10, the total number of antenna elements used by the beam port for each dimension of the antenna array is Is represented by
D _port = D _subarray 2 ^k 6 ^m 10 ⁿ , k = 0, 1, 2,. . . , M = 0, 1, 2,. . . , N = 0, 1, 2,. . .
Here, D _subarray is the number of elements used in the sub array in the target antenna array dimension. If only a single beam port is desired, a factor of 3 or 5 is also possible. Thus, according to one embodiment, if there are two beam ports, the extension weights map the two beam ports to the product of powers of 2, 6 or 10 sub-arrays per dimension. For example, the dimensional equation may be an orthogonal spatial dimension in a plane. Also, according to one embodiment, if there is one beam port, the extension weights map the two beam ports to a power of two, six or ten times that of one, three or five sub-arrays. That is, at a single beam port, the mapping can follow powers of two, six, and ten times three or five. In a two dimensional array, a mapping that includes an expansion factor of three or five can only be performed in one dimension.

  To make maximum use of the antenna array, the size of the subarray may be determined such that the size of the subarray covers the entire array, including feasible extensions. Thus, according to one embodiment, at least two non-overlapping sub-arrays together cover all the elements of the antenna array.

  All antenna elements in port mapping may be of the same amplitude and the extension itself provides full power utilization but the sub-array may not reach that level. One of the reasons for using all the antenna elements in the antenna array and for equalizing the sub-array port mapping and hence the beam port mapping amplitude is to use available power resources efficiently. In particular, this applies to the active antenna array in which the power amplifier is distributed, but likewise, as in the case of FIGS. 5 (a) and 5 (b), Also apply to an antenna array having a power distribution network 50 which also comprises an attenuator 52. This is particularly suitable for beamforming performed only via phase shifters. The number of sub-arrays used is given by combining the powers of 2, 6, and 10 and potentially multiplying by 3 or 5 for a single beam port.

  Thus, the extension weights describe how one or two beam ports with beam shapes given by a single sub-array can be mapped onto multiple sub-arrays. FIG. 6 schematically shows (a), (b) and (c) three different pairs of extension weights that extend the size of the antenna array by 2, 6 or 10 times respectively. is there.

  Further embodiments as to how the extension weights can be determined will now be disclosed.

  Extension weights within the pair may be associated such that the two beam ports have orthogonal polarizations. Thus, according to one embodiment, extension weights are defined to keep the polarizations of the two beam ports mutually orthogonal when there are two beam ports.

ここで、ｅａ_ｍは、あるポートをｍ個のサブアレイの倍数（または、本明細書に開示される拡張を用いたサブアレイの組合せ）にマッピングするための拡張重みを表し、ここで、Ｚ_ｒｃは、ｒ個の行とｃ個の列を有する全てがゼロの行列である。 According to one embodiment, the expansion weight at port a with the first polarization is determined as:

Here, e a _m represents an extension weight for mapping a port to m multiples of m sub-arrays (or a combination of sub-arrays using the extensions disclosed herein), where Z _rc is , A matrix of all zeros with r rows and c columns.

The extension weight at port b with the second polarization orthogonal to the first polarization is then determined as
eb _m = flipud ([ea _m (:, 2)-ea _m (:, 1)] ^* )
Here, e a _m (:, c) represents a column c of e a _m , ^* represents a complex conjugate, and flipud (x) reverses the row order of x. That is, the symbols a and b represent subarray ports, a combination of subarray ports, or two orthogonal polarizations for beam ports. This symbol does not point to specific polarizations for the various ports.

  As those skilled in the art will appreciate, these expansion matrices are merely examples. Other useful examples of expansion matrices can be obtained, for example, by applying phase shifts to the illustrated matrices.

The expansion factors may be concatenated to perform the expansion in two or more steps. Thus, according to one embodiment, before defining one or two beam ports, the sub-arrays are further expanded by further expansion weights. The order in which the extensions based on 2, 6 and 10 are applied is arbitrary, but the extension with 3 or 5 should be the last extension applied, as it will result in only a single beam port is there. These can be found from the previously defined ea ₆ and ea ₁₀ by removing the low zero part (ie Z ₃₂ and Z ₅₂ respectively) and not defining any eb mapping. FIG. 7 shows one illustrative example of how extensions can be used recursively to reach the desired size of the final weight vector. As shown in FIG. 7, the expansion factors may be concatenated with various expansion factors, with a first expansion factor of 6 (expansion × 6) followed by a second expansion factor of 2 (expansion × 2).

  An example of power utilization after expansion is shown in FIG. 8 for two antenna ports. As can be seen from the upper side of FIG. 8, one half of the antenna element of the first polarization is connected to port 1 (○) and the other half is connected to port 2 (*). A similar phenomenon applies to the second polarization, as shown at the bottom of FIG. This means that for an active antenna with distributed power amplifiers, the two antenna ports do not have to share the same power amplifier. The magnitude variations in FIG. 8 are, for the purpose of illustration, the definition of the subarrays used in this case where unequal amplitudes are selected to show how the amplitude variations of the subarrays are repeated throughout the array. Is due to

  In some cases, it may be beneficial if both beam ports share the same power amplifier, in other cases this is desirable, for example when a correlated signal is applied to two antenna ports. There is no such thing. One reason is that the signal correlated with the power amplifier in common leads to an uneven loading of the power amplifier.

If the antenna ports share a power amplifier, or if only a single antenna port is used, this can be achieved, for example, by adding together two extension weights, each defining a beam port, element by element. Thus, according to one embodiment, the extension weights of at least two sub-arrays are added to generate one of one or two beam ports. If an extension by 3 or 5 is used, the result is a single beam port mapped to all sub-array ports, i.e. using all power resources. Since the subarray expansion does not change the power pattern, the array coefficients (given by the total expansion vector / matrix) allow space for two beam ports to have the same power pattern as the subarray port. It may be white. According to one embodiment, a second subarray port of the second subarray port of the second subarray port of the second subarray port of the magnitude of the two-dimensional discrete Fourier transform of the first expanded weight matrix applied to the first subarray port of the subarray port The extension weights are determined such that all elements in the matrix defined by the sum of the second extension weight matrix applied and the square of the magnitude of the two-dimensional discrete Fourier transform have the same value. That is, the extension weight may be determined as follows.
| DFT (ea) | ² + | DFT (eb) | ² = k · J _rc
Here, DFT (ea) and DFT (eb) represent discrete Fourier transforms of ea and eb, respectively, ea and eb are sum expansion matrices applied to sub array ports a and b, respectively, and a is a sub array The first subarray port of the port, b is the second subarray port of the subarray port, k is a constant, and J _rc is all 1 with r rows and c columns It is a matrix of For a two-dimensional antenna array, the expanded weights are collected in a matrix. In the case of a one-dimensional antenna array, this matrix is folded into vectors (which can also be understood as a special case of a matrix having only one row or one column).

  We will now present in more detail how to generate the expansion weights in a uniform rectangular array. The origin is an expanded weight vector for each dimension as previously generated. These expanded weight vectors are combined into two matrices, one for each beam port.

ここで、ｗ_１ｙａおよびｗ_１ｙｂは、ｙなどの次元に沿った偏波ａおよびｂをそれぞれ有する要素に加えられるビームポート１での拡張重みを含む列ベクトルを表す。第２に、非共用リソースを有する、第２の次元（ここでは次元ｚ）に沿った２つのビームポートについての拡張重みベクトルが、次式の通り、連続した拡張を介して第１のポートについて決定される。

および、

ここで、ｗ_２ｚａおよびｗ_２ｚｂは、ｚの次元に沿った偏波ａおよびｂをそれぞれ有する要素に適用される第２のビームポート（すなわちビームポート２）での拡張重みを含む列ベクトルを表す。 First, an expanded weight vector for one beam port along a first dimension (here, dimension y) with non-shared resources is determined. If an extension with a factor of 3 or 5 is used for one of the dimensions (so that a single beam port using all resources is obtained), this dimension is here as the dimension of y It is selected. The complete vector for the first beam port (ie, beam port 1), including all elements (ie, both polarizations a and b), can be expressed as:

Here, w _1ya and w _1yb represent column vectors including the extension weights at beam port 1 to be applied to elements having polarizations a and b, respectively, along a dimension such as y. Second, the expanded weight vectors for the two beam ports along the second dimension (here, dimension z) with non-shared resources, for the first port via successive expansions, as It is determined.

and,

Here, w _2za and w _2zb denote column vectors including the extension weights at the second beam port (ie, beam port 2) applied to elements having polarizations a and b along the dimension of z, respectively .

Two vectors w _1z and w _2z are associated to provide orthogonal polarization and the same power pattern. This relationship is given by the following equation.

The symbol " ^* " stands here for complex conjugation (and not for Hermitian conjugate transposition).

これらのベクトルを組み合わせて、偏波ごとに１つの行列を形成し、これは、次式に従って均一長方形アレイ（ＵＲＡ）内の全ての素子を含む。

および、

Here, F is a matrix in which the order of elements (rows) in the vector is reversed, that is, a matrix having 1 at opposite angles and having zero at the other.

These vectors are combined to form one matrix per polarization, which includes all elements in a uniform rectangular array (URA) according to the following equation:

and,

  The phase adjustment factor β is used to ensure full power utilization. The actual value depends on how to specify the extension weight for each dimension. According to the procedure described herein, the phase adjustment is in most cases equal to one.

Finally, the expanded weight matrix at the second port is
w _{2 a} = F _z w ^{* 1} _b F _y
and,
w 2 _b = −F _z w ^* _{1 a} F _y
Here, F _z and F _y are matrices that have 1 on the diagonal and have zero elsewhere. If expansion factors 3 and 5 are not used, the result at this stage is two with the same power pattern, orthogonal polarization, non-shared resources (power amplifier), and full power utilization for the two beam ports It is an extended weight matrix that defines beam ports.

If shared resources are desired, this can be obtained by the following procedure. First, the matrices for the two ports are added as:
w _{1a_shared} = w _1a + w _2a
and,
w _{1b_shared} = w _1b + w _2b
The matrix for the second port is then formed by performing the following operation:
w _{2a_shared} = F _z w ^{* 1} _{b_shared} F _y
w _{2b_shared} = −F _z w ^* _{1a_shared} F _y
If an expansion factor of 3 or 5 is used, the result is an expansion matrix defining one beam port with the power pattern provided by the sub-array instead. The expansion matrix connects beam ports to all power resources so that all power resources are utilized. Since the first beam port already uses all resources, the desired power pattern with the first beam port if the second beam port is created as described above without adding the extension weight And a second beam port is found having shared resources of and orthogonal polarization.

  FIG. 9 schematically shows the components of the antenna device 100 according to one embodiment with respect to several functional units. The processing unit 21 may be one or more of a suitable central processing unit (CPU), multiprocessor, microcontroller, digital signal processor (DSP), application specific integrated circuit (ASIC), field programmable gate array (FPGA), etc. , And may execute software instructions stored in the form of computer program product 130 (as in FIG. 13), for example storage medium 103. Thus, the processing unit 101 is thereby configured to perform the method disclosed herein. For example, processing unit 101 may be configured to generate any sub-array as in FIG. 4 and to map to beam ports as in FIGS. 6 and 7 as disclosed herein. .

  The storage medium 103 may also comprise persistent storage, which may be, for example, any single device or combination of magnetic storage, optical storage, solid state storage, or remote storage. it can. The antenna device 100 may further include a communication interface 22 for transmitting and receiving signals. Thus, the communication interface 22 may comprise an antenna array as in any of FIGS. 1, 2, 3 and 5.

  The processing unit 21 transmits data and control signals to the communication interface 102 and the storage medium 103, receives data and reports from the communication interface 102, and retrieves data and instructions from the storage medium 103, for example. Control the overall operation. Other components of the antenna apparatus 100 as well as related functions are omitted so as not to obscure the ideas presented herein.

  FIG. 10 schematically shows the components of the antenna device 100 according to an embodiment with respect to several functional modules. The antenna device 100 of FIG. 10 includes several functional modules, ie, a generation module configured to execute step S102 below, and a transmission / reception module 101b configured to execute step S104 below. Equipped with The antenna device 100 of FIG. 10 may further comprise some optional functional modules. The function of each functional module 101a-101b is apparent from the situation where this functional module 101a-101b may be used. Generally speaking, each functional module 101a-101b may be implemented in hardware or software. Preferably, one or more or all of the functional modules 101a-101b may be implemented by the processing unit 10, possibly in conjunction with the functional units 102 and / or 103. Thus, the processing unit 101 may be configured to fetch from the storage medium 103 the instructions presented by the functional modules 101a-101b and execute these instructions, whereby any of the disclosures described below Execute the step

  The antenna array 1 and / or the antenna device 100 may be realized as an integrated circuit, as a stand-alone device or as part of a further device. For example, the antenna array 1 and / or the antenna device 100 may be provided in a wireless transmitting / receiving device such as the network node 110 or the wireless device 120. FIG. 11 shows a network node 110 comprising at least one antenna array 1 and / or an antenna arrangement 100 as disclosed herein. The network node 110 may be a BTS, a Node B, an eNB, a relay apparatus, a backhaul node, or the like. FIG. 12 shows a wireless device 120 comprising at least one antenna array 1 and / or antenna device 100 as disclosed herein. The wireless device 120 may be a user equipment (UE), a mobile phone, a tablet computer, a laptop computer, etc.

  The antenna array 1 and / or the antenna device 100 may be realized as an integral part of a further device. That is, the components of the antenna array 1 and / or the antenna device 100 may be integrated with the other components of the further device and share the further device and some components of the antenna array 1 and / or the antenna device 100 You may For example, if the further device comprises a processing unit in this way, this processing unit may be configured to carry out the operation of the processing unit 31 associated with the antenna device 100. Alternatively, the antenna array 1 and / or the antenna arrangement 100 may be realized as separate units in a further arrangement.

  An example of a computer program product 130 including computer readable means 132 is shown in FIG. On this computer readable means 132 a computer program 131 can be stored, by means of which the processing unit 101, 21 as well as the entities and devices operatively coupled to the processing unit, for example the communication interface 102. And storage medium 103 may be capable of performing the methods according to the embodiments described herein. Thus, computer program 131 and / or computer program product 130 may provide a means for performing any of the steps disclosed herein.

  In the example of FIG. 13, computer program product 130 is illustrated as an optical disc, such as a CD (compact disc) or a DVD (digital versatile disc) or a Blu-ray disc. The computer program product 130 may also be a memory such as a random access memory (RAM), a read only memory (ROM), an erasable programmable read only memory (EPROM), or an electrically erasable programmable read only memory (EEPROM). More specifically, it can also be implemented as a non-volatile storage medium of the device in an external memory such as a USB (Universal Serial Bus) memory or a flash memory such as a compact flash memory. Thus, although the computer program 131 is schematically illustrated here as a track on the illustrated optical disc, the computer program 131 can be stored in any manner suitable for the computer program product 130.

  Referring now to FIG. 14, a method for beamforming using antenna array 1 according to one embodiment is shown. The antenna array 1 includes two polarization elements. This method is performed by the antenna device 100 provided with the antenna array 1. This method is advantageously implemented as a computer program 32.

  The antenna device 100 is set to generate one or two beam ports in step S102. The one or two beam ports are defined by combining at least two non-overlapping sub-arrays. Each subarray has two subarray ports. The two sub-array ports have identical power patterns and mutually orthogonal polarizations in each sub-array. The at least two subarrays that do not overlap are combined via the expansion weights. The extension weights map the one or two beam ports to the sub-array port such that one or two beam ports have the same power pattern as the sub-array. At least some of the extension weights have the same non-zero magnitude and are associated with phases that form a transmit lobe. The antenna device 100 is set to transmit a signal using one or two beam ports at step S104.

  FIG. 15 shows an example of a transmission lobe (beam pattern) of the first beam port (beam port 1) at an azimuth beam half width (HPBW) = 50 ° and an elevation angle HPBW = 25 °.

  FIG. 16 shows an example of the transmission lobe (beam pattern) of the second beam port (beam port 2) at an azimuth angle HPBW = 50 ° and an elevation angle HPBW = 25 °, and this second beam port The shape of the transmission lobes of is the same as the shape of the first beam port (ie, the shape of the transmission lobes in FIG. 15). Thus, the transmit lobes of FIGS. 15 and 16 have the same power pattern. This lobe has orthogonal polarization in any direction (although not apparent from FIGS. 15 and 16).

  An example of a broad beam pattern produced by conventional (SPBF) beamforming is shown in FIG. The corresponding weighting factors are shown on the left side of FIG. Thus, many weighting factors have amplitudes set to zero, which results in very low utilization of power resources.

  FIG. 18 shows an example of a broad beam pattern created by conventional (SPBF) beamforming, limited only to phase tapers for good power resource utilization. The corresponding weighting factors are shown on the left side of FIG. However, it turns out that the ripple of the beam pattern obtained as a result is large.

  An example of a broad beam pattern formed in accordance with the embodiments disclosed herein is shown in FIG. This beam pattern has the desired shape, here HPBW = 50 °, and the power resource utilization is very good. The corresponding weight factors are shown on the left side of FIG.

The inventive concept has mainly been described above with reference to several embodiments. However, as will be readily appreciated by those skilled in the art, other embodiments besides those previously disclosed are equally feasible within the scope of the inventive concept as defined by the appended claims. . For example, although using LTE-specific terminology, the embodiments disclosed herein may be modified to be applicable to non-LTE based communication networks as well.

のように決定され、
ここで、ｅａ _ｍ が、前記１つまたは２つのビームポートのうちの１つのビームポートを、ｍ個のサブアレイの倍数にマッピングするための前記拡張重みを表し、Ｚ _ｒｃ が、ｒ個の行とｃ個の列を有する全てがゼロの行列である、態様１に記載の方法。
（態様１２）
前記第１の偏波に直交する第２の偏波を有するポートｂについての前記拡張重みが、ｅｂ _ｍ ＝ｆｌｉｐｕｄ（［ｅａ _ｍ （：，２）−ｅａ _ｍ （：，１）］ ^＊ ）のように決定され、
ここで、ｅａ _ｍ （：，ｃ）が、ｅａ _ｍ の列ｃを表し、 ^＊ が複素共役を表し、ｆｌｉｐｕｄ（ｘ）が、ｘの行順序を逆にする、態様１１に記載の方法。
（態様１３）
前記信号が、ブロードキャスト情報およびシステム情報のうち少なくとも一方を含む、態様１に記載の方法。
（態様１４）
アンテナアレイ（１）を備えるアンテナ装置（１００）であって、前記アンテナアレイがビーム形成用の２偏波素子を備え、前記アンテナアレイはさらに処理ユニット（３１）を備え、前記処理ユニット（３１）は、前記アンテナアレイ（１）に、
１つまたは２つのビームポートを生成させるように設定され、前記ビームポートが、オーバラップしていない少なくとも２つのサブアレイを組み合わせることによって規定され、
各サブアレイが、２つのサブアレイポートを有し、前記２つのサブアレイポートが、同一の電力パターンおよび相互に直交する偏波を有し、
前記オーバラップしていない少なくとも２つのサブアレイが拡張重みを介して組み合わされ、
前記１つまたは２つのビームポートが前記サブアレイと同じ電力パターンを有するように、前記拡張重みが、前記１つまたは２つのビームポートをサブアレイポートにマッピングし、
前記拡張重みの少なくともいくつかが、同一の非ゼロの大きさを有し、送信ローブを形成するような位相に関連付けられ、
前記拡張重みが、拡張行列内で収集され、前記拡張行列が空間的に白色になるように決定され、
前記処理ユニット（３１）はさらに、前記アンテナアレイ（１）に、
前記１つまたは２つのビームポートを使用して信号を送信させるように設定される、アンテナ装置。
（態様１５）
態様１４に記載のアンテナ装置（１００）を備える、ネットワークノード（１１０）。
（態様１６）
態様１４に記載のアンテナ装置（１００）を備える、ワイヤレス装置（１２０）。
（態様１７）
２偏波素子を備えるアンテナアレイ（１）を使用してビーム形成するためのコンピュータプログラム（１３１）であって、コンピュータプログラムコードを含み、処理ユニット（３１）上で実行されると、前記コンピュータプログラムコードは、前記アンテナアレイ（１）に、
１つまたは２つのビームポートを生成させ（Ｓ１０２）、前記ビームポートが、オーバラップしていない少なくとも２つのサブアレイを組み合わせることによって規定され、
各サブアレイが、２つのサブアレイポートを有し、前記２つのサブアレイポートが、同一の電力パターンおよび相互に直交する偏波を有し、
前記オーバラップしていない少なくとも２つのサブアレイが拡張重みを介して組み合わされ、
前記１つまたは２つのビームポートが前記サブアレイと同じ電力パターンを有するように、前記拡張重みが、前記１つまたは２つのビームポートをサブアレイポートにマッピングし、
前記拡張重みの少なくともいくつかが、同一の非ゼロの大きさを有し、送信ローブを形成するような位相に関連付けられ、
前記拡張重みが、拡張行列内で収集され、前記拡張行列が空間的に白色になるように決定され、
前記コンピュータプログラムコードはさらに、前記アンテナアレイ（１）に、
前記１つまたは２つのビームポートを使用して信号を送信させる（Ｓ１０４）、コンピュータプログラム。
（態様１８）
態様１７に記載のコンピュータプログラム（１３１）、および前記コンピュータプログラムが記憶されるコンピュータ読取り可能な手段（１３２）を含む、コンピュータプログラム製品（１３０）。 The inventive concept has mainly been described above with reference to several embodiments. However, as will be readily appreciated by those skilled in the art, other embodiments besides those previously disclosed are equally feasible within the scope of the inventive concept as defined by the appended claims. . For example, although using LTE-specific terminology, the embodiments disclosed herein may be modified to be applicable to non-LTE based communication networks as well.
The present invention includes the embodiments described below.
(Aspect 1)
Method for beamforming using an antenna array (1) comprising two polarization elements, comprising
Generating one or two beam ports (S102), wherein the one or two beam ports are defined by combining at least two non-overlapping sub-arrays;
Each subarray has two subarray ports, and the two subarray ports have the same power pattern and mutually orthogonal polarizations,
The at least two non-overlapping sub-arrays are combined via an extension weight,
The extension weights map the one or two beam ports to a sub-array port such that the one or two beam ports have the same power pattern as the sub-array;
At least some of the extension weights have the same non-zero magnitude and are associated with phases that form a transmit lobe,
Generating (S102), wherein the expansion weights are collected in an expansion matrix and the expansion matrix is determined to be spatially white;
Transmitting a signal using the one or two beam ports (S104)
Method, including.
(Aspect 2)
The extension weights map the one or two beam ports to a sub-array port, such that the one or two beam ports have the same power pattern as the sub-array, and there are two beam ports. A method according to aspect 1, wherein the two beam ports have mutually orthogonal polarizations in any direction.
(Aspect 3)
The method according to aspect 1, wherein the extension weights are defined such that, when there are two beam ports, the polarizations of the two beam ports are kept orthogonal to each other.
(Aspect 4)
The method according to aspect 1, wherein when there are two beam ports, the extension weights map the two beam ports to the product of powers of 2, 6 or 10 sub-arrays per dimension.
(Aspect 5)
The method according to aspect 1, wherein, when there is one beam port, the extension weights map the two beam ports to powers of two, six, and / or ten times that of one, three, or five sub-arrays. Method.
(Aspect 6)
The method according to aspect 1, wherein before defining the one or two beam ports, the sub-arrays are further expanded by further expansion weights.
(Aspect 7)
The second square of the magnitude of the two-dimensional discrete Fourier transform of the first expanded weight matrix applied to the first subarray port among the subarray ports, and the second applied to the second subarray port of the subarray port The extended weight is determined such that all elements in the matrix defined by the sum of the size of the two-dimensional discrete Fourier transform of the extended weight matrix and the square have the same value. Method.
(Aspect 8)
The extension weight is determined such that | DFT (ea) | ² + | DFT (eb) | ² = k · J _rc ,
Here, DFT (ea) and DFT (eb) represent discrete Fourier transforms of ea and eb, respectively, ea and eb are sum expansion matrices applied to the sub-array ports a and b, respectively, and a is The first subarray port of the subarray ports, b is the second subarray port of the subarray ports, k is a constant, and J _rc has r rows and c columns Aspect 8. The method according to aspect 1, wherein the matrix is all ones.
(Aspect 9)
The method according to aspect 1, wherein the at least two non-overlapping sub-arrays together cover all the elements of the antenna array.
(Aspect 10)
The method according to aspect 1, wherein the expansion weights of the at least two sub-arrays are added to generate one of the one or two beam ports.
(Aspect 11)
The extension weight for port a having a first polarization is

Determined as
Here, e a _m represents the extension weight for mapping one beam port of the one or two beam ports to a multiple of m sub-arrays, and Z _rc represents r rows and The method of aspect 1, wherein the matrix is all zeros having c columns.
(Aspect 12)
The extension weight for the port b having a second polarization orthogonal to the first polarization is e b _m = flipud ([ea _m (:, 2) -ea _m (:, 1)] ^* ) As determined
Where the e a _m (:, c) represents the column c of e a _m , ^* represents the complex conjugate, and flipud (x) reverses the row order of x.
(Aspect 13)
The method according to aspect 1, wherein the signal comprises at least one of broadcast information and system information.
(Aspect 14)
An antenna device (100) comprising an antenna array (1), wherein the antenna array comprises two polarization elements for beam formation, the antenna array further comprising a processing unit (31), the processing unit (31) Is the antenna array (1),
Set to produce one or two beam ports, said beam ports being defined by combining at least two non-overlapping sub-arrays,
Each subarray has two subarray ports, and the two subarray ports have the same power pattern and mutually orthogonal polarizations,
The at least two non-overlapping sub-arrays are combined via an extension weight,
The extension weights map the one or two beam ports to a sub-array port such that the one or two beam ports have the same power pattern as the sub-array;
At least some of the extension weights have the same non-zero magnitude and are associated with phases that form a transmit lobe,
The extension weights are collected in an extension matrix, and the extension matrix is determined to be spatially white,
The processing unit (31) further comprises the antenna array (1)
An antenna apparatus configured to transmit a signal using the one or two beam ports.
(Aspect 15)
Network node (110), comprising the antenna device (100) according to aspect 14.
(Aspect 16)
Wireless device (120), comprising an antenna device (100) according to aspect 14.
(Aspect 17)
A computer program (131) for beamforming using an antenna array (1) comprising two polarization elements, comprising computer program code and running on a processing unit (31), said computer program A cord is attached to the antenna array (1)
Generating one or two beam ports (S102), said beam ports being defined by combining at least two non-overlapping sub-arrays,
Each subarray has two subarray ports, and the two subarray ports have the same power pattern and mutually orthogonal polarizations,
The at least two non-overlapping sub-arrays are combined via an extension weight,
The extension weights map the one or two beam ports to a sub-array port such that the one or two beam ports have the same power pattern as the sub-array;
At least some of the extension weights have the same non-zero magnitude and are associated with phases that form a transmit lobe,
The extension weights are collected in an extension matrix, and the extension matrix is determined to be spatially white,
The computer program code is further coupled to the antenna array (1)
A computer program for transmitting a signal using the one or two beam ports (S104).
(Aspect 18)
A computer program product (130) comprising the computer program (131) according to aspect 17 and computer readable means (132) in which the computer program is stored.

Claims (18)

Method for beamforming using an antenna array (1) comprising two polarization elements, comprising
Generating one or two beam ports (S102), wherein the one or two beam ports are defined by combining at least two non-overlapping sub-arrays;
Each subarray has two subarray ports, and the two subarray ports have the same power pattern and mutually orthogonal polarizations,
The at least two non-overlapping sub-arrays are combined via an extension weight,
The extension weights map the one or two beam ports to a sub-array port such that the one or two beam ports have the same power pattern as the sub-array;
Generating (S102) at least some of the extension weights have the same non-zero magnitude and are associated with a phase that forms a transmit lobe;
Transmitting a signal using the one or two beam ports (S104).   The extension weights map the one or two beam ports to a sub-array port, such that the one or two beam ports have the same power pattern as the sub-array, and there are two beam ports. The method according to claim 1, wherein the two beam ports have mutually orthogonal polarizations in any direction.   The method according to claim 1, wherein the extension weights are defined to keep the polarizations of the two beam ports mutually orthogonal if there are two beam ports.   The method according to claim 1, wherein when there are two beam ports, the extension weights map the two beam ports to the product of powers of 2, 6 or 10 subarrays per dimension.   The method according to claim 1, wherein when there is one beam port, the extension weights map the two beam ports to powers of two, six, and / or ten times that of one, three, or five subarrays. the method of.   The method according to claim 1, wherein the sub-arrays are further expanded by further expansion weights before defining the one or two beam ports.   The second square of the magnitude of the two-dimensional discrete Fourier transform of the first expanded weight matrix applied to the first subarray port among the subarray ports, and the second applied to the second subarray port of the subarray port The expansion weight is determined such that all elements in the matrix defined by the sum of the size and the square of the two-dimensional discrete Fourier transform of the expansion weight matrix have the same value. the method of. The extension weight is determined such that | DFT (ea) | ² + | DFT (eb) | ² = k · J _rc ,
Here, DFT (ea) and DFT (eb) represent discrete Fourier transforms of ea and eb, respectively, ea and eb are sum expansion matrices applied to the sub-array ports a and b, respectively, and a is The first subarray port of the subarray ports, b is the second subarray port of the subarray ports, k is a constant, and J _rc has r rows and c columns The method according to claim 1, wherein the matrix is all ones.   The method of claim 1, wherein the at least two non-overlapping sub-arrays together cover all elements of the antenna array.   The method of claim 1, wherein the extension weights of the at least two sub-arrays are added to generate one of the one or two beam ports. The extension weight for port a having a first polarization is

Determined as
Here, e a _m represents the extension weight for mapping one beam port of the one or two beam ports to a multiple of m sub-arrays, and Z _rc represents r rows and The method according to claim 1, wherein the matrix is all zeros having c columns. The extension weight for the port b having a second polarization orthogonal to the first polarization is e b _m = flipud ([ea _m (:, 2) -ea _m (:, 1)] ^* ) As determined
The method according to claim 11, wherein ea _m (:, c) represents the column c of e a _m , ^* represents the complex conjugate, and flipud (x) reverses the row order of x.   The method of claim 1, wherein the signal comprises at least one of broadcast information and system information. An antenna device (100) comprising an antenna array (1), wherein the antenna array comprises two polarization elements for beam formation, the antenna array further comprising a processing unit (31), the processing unit (31) Is the antenna array (1),
Set to produce one or two beam ports, said beam ports being defined by combining at least two non-overlapping sub-arrays,
Each subarray has two subarray ports, and the two subarray ports have the same power pattern and mutually orthogonal polarizations,
The at least two non-overlapping sub-arrays are combined via an extension weight,
The extension weights map the one or two beam ports to a sub-array port such that the one or two beam ports have the same power pattern as the sub-array;
At least some of the extension weights have the same non-zero magnitude and are associated with phases that form a transmit lobe,
The processing unit (31) further comprises the antenna array (1)
An antenna apparatus configured to transmit a signal using the one or two beam ports.   A network node (110), comprising an antenna arrangement (100) according to claim 14.   A wireless device (120) comprising the antenna device (100) according to claim 14. A computer program (131) for beamforming using an antenna array (1) comprising two polarization elements, comprising computer program code and running on a processing unit (31), said computer program A cord is attached to the antenna array (1)
Generating one or two beam ports (S102), said beam ports being defined by combining at least two non-overlapping sub-arrays,
Each subarray has two subarray ports, and the two subarray ports have the same power pattern and mutually orthogonal polarizations,
The at least two non-overlapping sub-arrays are combined via an extension weight,
The extension weights map the one or two beam ports to a sub-array port such that the one or two beam ports have the same power pattern as the sub-array;
At least some of the extension weights have the same non-zero magnitude and are associated with phases that form a transmit lobe,
The computer program code is further coupled to the antenna array (1)
A computer program for transmitting a signal using the one or two beam ports (S104). A computer program product (130) comprising the computer program (131) according to claim 17 and computer readable means (132) in which the computer program is stored.

Images