Patent ID: 12230890

DETAILED DESCRIPTION OF THE INVENTION

Equal or equivalent elements or elements with equal or equivalent functionality are denoted in the following description by equal or equivalent reference numerals even if occurring in different figures.

Embodiments described herein relate to beams, in particular, in connection with techniques relating to beamforming. Beams associated to a device, e.g., a DUT, may define one or more advantageous directions along which electromagnetic energy is emitted with the DUT, or along with electromagnetic energy may be received with the DUT. In the case of transmitting a signal, the beam may comprise one or more main lobes and one or more side lobes, wherein a main lobe refers to a desired radiation pattern and/or a direction thereof. A side lobe may relate to a disturbing and/or inevitable direction along which radiation is emitted with a respective pattern. This description refers without any limitation to the receive scenario in which, comparable to a directional characteristic of a microphone, directions may be defined with the main lobes that allow for a high gain during reception of electromagnetic energy. Therefore, when referring to a beam, this shall be understood as relating to the transmit scenario and/or the receive scenario. Although referring to, hereinafter, to beams, the embodiments relate to other forms of electromagnetic wave transmit or receive pattern, i.e., an electromagnetic pattern at the radio frequency without any limitation. Such patterns may be referenced to by a source described by a point that forms the transmit and/or receive pattern along a line or plane/surface. An example for such electromagnetic wave transmit or receive patterns may be implemented by a leaky feeder line, i.e., a cable with slots to radiate perpendicular to the cable. Such a leaky feeder line may be used to connect trains in tunnels. In this particular example, the reference for the emitted electromagnetic field may be a line.

A DUT according to the disclosed embodiments may be any device that is configured to radiate and/or receive electromagnetic radiation at radio frequency for wireless communication, for example, a user equipment (UE), a base station (BS) and/or an active antenna system (AAS).

Embodiments described herein may relate to probes that may be used in a measurement system. Such a probe may comprise active elements such as an antenna element and/or an antenna array configured to generate and/or transmit electromagnetic energy, for example, when performing beamforming within the measurement system. Alternatively or in addition, the probe may comprise sensing elements, for example, an antenna (element) and/or an antenna array, that is configured to receive electromagnetic energy that may be emitted, for example, with the DUT. Thus, when referring to a DUT forming a beam that is detected or determined with the measurement system, this may relate to a transmission of electromagnetic energy with one or more probes, the electromagnetic energy to be received with the DUT, wherein the DUT may transmit a feedback signal indicating one or more characteristics of reception. Alternatively or in addition, the DUT may be adapted to transmit electromagnetic energy, wherein the probes may receive said energy and may feedback a characteristic of reception to the measurement system and/or information that allows to determine such a characteristic with the measurement system.

Embodiments described herein may relate to antenna arrays that are used for receiving and/or transmitting electromagnetic radiation. An antenna array may comprise one or a higher number of antennas, for example, at least one, at least two, at least five, at least ten or a higher number such as more than 50 or the like. Thus, an antenna array shall not be limited to a structure comprising a plurality of antennas but may also comprise only one antenna.

FIG.1is a schematic flowchart of a method100according to an embodiment. Method100comprises a step110in which a Center-of-Radiation Reference (CORR) is defined for a device under test. The CORR may relate to a point (CORRP), a line (CORRL) or an area (CORRA). Thus, P in CORRP can also have the meaning of line and surface beyond the usual meaning of point. The CORR indicates a reference origin of an electromagnetic wave pattern, e.g., a beam or a different pattern, formable with the DUT. The CORR may be, for example, congruent with the reference origin or may comprise same at least partially. Alternatively, the CORR may be arranged at a different position and may comprise information about an offset between the CORR and the reference origin. In a step120a 3-dimensional orientation information is determined with respect to the CORR, the 3-dimensional orientation information indicating a direction of the electromagnetic wave pattern. The 3-dimensional orientation information may be referred to as location information. A combination of the CORR and the 3-dimensional orientation information allows to specify the origin and the propagation of the electromagnetic wave pattern in space. A step130comprises providing the CORR and the 3-dimensional orientation information (location information) to a measurement system.

In the following, embodiments will be described with reference to a Center-of-Radiation Reference Point (CORRP). The examples described may refer, without any limitation to CORR in general and/or to CORRL and/or CORRA in specific. I.e., although the CORRP is named as a point and thus with a minimum extension in space, the CORRP may alternatively relate to a direction or line along which the radiation extends. For example, the CORRP may be arranged along or parallel to a center of a main lobe of the radiation. In other words, the center-of-radiation may also be a line such as a leaky feeder cable. Furthermore, a direction starting from or ending in the center of radiation is to be described/defined by embodiments in order to describe a radiated and/or received antenna pattern which is to be measured when investigating/measuring the DUT. The CORR may be a virtual projection into a point, line or plain, e.g., in case that a multitude of antennas is distributed at distances of several wavelengths and the resulting far filed antenna pattern is a superposition of the radiated electromagnetic waves from the individual antennas.

Instead of only one CORR/CORRP, a plurality of two or even more CORR may be defined. The different CORR may be defined, for example, at different positions inside and/or outside and/or at the surface of the DUT. The location information for a single electromagnetic wave pattern/beam may be generated for one, some or each of the plurality of CORR, i.e., a specific electromagnetic wave pattern formed with the DUT may be described by one or more location information relating to a specific CORR each. This may allow to enhance practical measurements. For example, when considering a car as a DUT, such variety of CORRP may be helpful in practical terms if, e.g., the radiated pattern inside or outside of a car is measured.

FIG.2is a schematic flowchart of a method200that may be implemented, for example, when performing the step110. A step210comprises determining a set of reference markers at the DUT, the set of reference markers visible when looking at the DUT. This may include but is not limited to a visibility of the set of reference markers when using human eyes. A set of reference markers visible when looking at the DUT may alternatively or in addition comprise a use of technical means to identify markers that are invisible for the human eye. Examples for such markers are small markers or markers that use physical properties beyond human capabilities, for example, ultraviolet markers or infrared markers, as well as, use of temperature, embedded magnetic sources or the like. Thus, the markers may at least be accessible. A step220comprises defining a coordinated system using the reference markers. The coordinate system may be referred to as a first coordinate system or a global coordinate system that allows to navigate through a three-dimensional space. For example but not necessarily, the defined coordinate system may comprise three perpendicular axes, i.e., it may be formed as a Cartesian coordinate system. Alternatively or in addition, other coordinate systems may be used, for example, a spherical coordinate system or a cylindrical coordinate system or a linear coordinate system or a planar coordinate system. A step230comprises defining the CORRP within the coordinate system. The CORRP may be selected or defined as an arbitrary point within in the coordinate system. For example, the CORRP may be a specific point within the measurement environment such as a specific probe or object. The coordinate of the CORRP may indicate a relative position of the CORRP and the DUT and may thus relate to an exact positioning of the DUT within the measurement environment such as a measurement chamber. Alternatively, the CORRP may be any other point, e.g., decoupled from objects in the measurement environment.

Based on the definition of the coordinate system in connection with the reference markers that are connected to the DUT, the CORRP is thereby also connected to the DUT and probably to the measurement environment which allows linking the position of the DUT with positions in the measurement environment. Advantageously, the reference markers are immobile in the present test scenario, i.e., the CORRP is also immobile with respect to the DUT. For example, the set of reference markers may at least partially be an immobile marker such as a physical feature, e.g., a lens of the DUT, a light emitting device of the DUT, e.g., a flashlight, an electrical port and/or an acoustical port of the DUT and/or an electromagnetic or magnetic pattern. According to embodiments, the set of reference markers may at least be partially implemented by a signal pattern that may be displayed at a display of the DUT, which may therefore be referred to as an optical signal pattern. This allows for obtaining, determining and reproducing the CORRP based on the set of reference markers. Thereby, the location information characterizing the beam formable with the DUT, may also be evaluated using the set of reference markers and thereby without precise knowledge of an interior of the DUT.

FIG.3shows a schematic perspective view of a DUT30according to an embodiment, for describing the method100and200.

A set of reference markers321,322and323may be arranged at a housing34of the DUT30. The set of reference markers321to323may be arranged on a same side of the DUT housing34but may also be arranged at different sides with respect to each other. Although three markers321to323may be sufficient to define a three-dimensional coordinate system,36, a higher number of references markers may also be used. It is also possible to use a lower number, for example, 2, when the geometric relation between the two selected reference markers is known, wherein the known geometric relation may therefore provide for the missing information.

A center of origin38of the three-dimensional coordinate system36may comprise an arbitrary location and may be located, by non-limiting example only, at a location of one of the reference markers321,322or323, such as322. Alternatively, any other position within the 3D coordinate system36may be used as reference position as any other position therein may be referred to it.

In other words, the reference markers or reference points321to323marked with A,B,C may be arranged outside of the DUT30and may span the coordinate system36and/or may define the center of origin38of the coordinate system36.

According to 3GPP relative coordinate systems421and422may be be defined in connection with antenna arrays421and422of the DUT30. A different number of antenna arrays44may be present, for example, 1, 3, 4 or more. For defining the relative coordinate systems421in connection with antenna array441and the relative coordinate system422in connection with the antenna array442relative pointers461and462may be used to point to reference positions481,482respectively of the antenna arrays441,442respectively. This involves precise knowledge of a position of the antenna arrays441and442. This contradicts the interest of manufactures to not disclose the precise location of the antenna array which might give a hint on how beams are exactly generated.

According to the present disclosure, a CORRP52is defined in an arbitrary position of the three-dimensional coordinate system36. Thereby, the CORR may be defined so as to correlate to one or more of the markers321to323of the DUT as well as to the reference origin of an emitted beam. The CORR may be located at a position of at least one of the markers321to323. At this step, knowledge about a measurement condition or environment may be used, i.e., how the DUT will be positioned within later tests. I.e., the CORRP52may be arranged at another location, for example, outside a volume of the DUT30, i.e., outside the housing34. Alternatively, the CORRP may be defined at the surface of an enclosure of the DUT or inside the enclosure of the DUT e.g. inside a car. The CORRP52may be set to a specific point within that environment. Alternatively or in addition, the CORRP52may be congruent with one of the set of reference markers321,322or323, or even with the center of origin in38. When the position of the DUT is known in later tests, this is thereby true for the set of reference markers. According to the present embodiments, reference origins541and/or542of beams561and/or562may be defined as part of the location information. The reference origin may be understood as a physical or theoretical origin of the beam. Such an origin may be different from the reference position48, in particular, when the reference position48indicates a center of the antenna array. For generating a specific beam56, a subset of antenna elements of the antenna array44may be used such that the beam may have a reference origin being anywhere on the antenna array. In particular, different beams may comprise different reference origins on the antenna array. The location information may include further information such as a positioning of an surface of the antenna array in the 3D space, a directions of emissions (beams), and/or a reference point (reference origin) in combination with vectors for emission. The location information may further comprise information such as information indicating a power used for forming the wave patter e.g., a used power and/or a power class of the beam. For example, a side lobe suppression may be performed with an antenna array by tapering and/or if a beam is emitted at high power, medium or low power. Alternatively or in addition, the location information associated with the CORRP may comprise information, e.g., about the carrier frequency and/or the intended kind of beam pattern, i.e., information indicating the 3D pattern, to be radiated. Furthermore, the location information may comprise information indicating if the radiated beam is composed/superimposed by of one or several individual beams. This allows the CORRP being different from each other, i.e., for the components superimposing. In some scenarios, e.g., during measurements in the near filed, a joint information may be questionable and/or not meaningful, wherein an information relating to the single components may be of advance. Such a case may be of interest, if e.g. a common signal is transmitted with the superposition of the two or more beams while other part of information is transmitted only using the one or not all superpositioned beams. This may be relevant for control channel information, while user data might be multiplexed to independent beams (time-frequency resources might be differently mapped onto spatially resources provided by the beams).

When considering now a use of two or more antenna arrays, for example, both of the antenna arrays441and442to generate a combined beam563, it may occur that a reference origin543of the beam563may even be outside one or both of the antenna arrays441and442. By non-limiting example, the beams561and562may both together form the beam563. The beams561and562may be distinguishable or discriminable in the near field but may form the common beam563in the far field. In the far field, the beam563may therefore have a single reference origin543associated with beam563.

When considering now a DUT enclosed by a housing34and unknown positions of the antenna arrays441and442therein, it is difficult to evaluate beams generated by one or more of the antenna arrays441and/or442. With information according to 3GPP that rely on the position of the antenna arrays. In contrast here to, when the defining the reference origins and further defining directions581,582and/or583associated with the beams561to563, a radiation of the antenna arrays, i.e., the beams, may be measured even in absence of knowledge relating to the position of the antenna elements. According to some embodiments, e.g., the beam563, the position of the antenna441and442may even be unimportant when forming the common beam563. The directions581,582and/or583may be defined as a direction within the 3D coordinate system36and may therefore relate to a direction with respect to the set f markers321to323.

The CORR52may be a position in a 3D space. The 3-dimensional orientation information may be a vector in the same space, wherein the CORR may be used as reference location or as a center. The CORR may thus contain a reference with respect to the accessible markers32, wherein every position and/or direction, i.e., wave pattern origins and directions thereof may be described with respect to the CORR and thereby to the markers.

FIG.3bis a schematic perspective view of a part of a measurement environment31that may be used to evaluate the DUT30. For example, the measurement environment31may receive or obtain information about the set of markers321to323that allows to determine a position and/or orientation, advantageously both, of the DUT in the three-dimensional space, advantageously in the coordinate system36. The measurement environment31may comprise a device33configured to detect at least some of the set markers321to323at the DUT30. The device33may be, for example, a camera, a scanner, a reader or the like.

The measurement environment31may comprise a structure35configured to define and/or adapt the position of the DUT30. The structure35may be or may include a carrier, a fixture, a jig, a holder, a mount, a container, a positioner or the like in order to hold the DUT30for OTA measurements to then be made using probes that are not shown inFIG.3b. During the tests, the structure35may be configured to move the DUT30with respect to not shown probes, e.g., rotate and/or tilt and/or translate the DUT30. Alternatively or in addition the not shown probes may be moved with respect to the DUT30. According to embodiments, the DUT30may be placed and/or moved by a manual placement, a robot or manipulator placement, a conveyer belt, an automatic and/or semi-automatic handling system or the like.

The measurement environment31, for example, a control unit thereof, may link information relating to the position of the set of markers321to323within the measurement environment31with the location information indicating the position of the CORRP52. Thereby a link between positions and coordinates within the measurement environment31and the 3D coordinate system being defined by the set of markers32to323may be obtained. Thus, by combining the known position of the markers321to323, i.e., plane(s) and/or edge(s) and/or corner(s) and/or some other feature(s) of the DUT30, together with the CORRP52, the appropriate placement of the DUT in the structure35may be ensured. The control unit may use information about the position of the structure35within the environment and information of the markers321to323within the measurement environment, e.g., of the markers321to323relative to the device33that has a known relative position with respect to the structure35. The control unit may further have knowledge about further parameters of the DUT, e.g., a position of edges, surfaces or planes with respect to the markers321to323and thereby about a shape of the DUT.

A method according to embodiments may comprise determining of a position of the DUT using a set of markers321to323of the DUT30and determining an expected location for the radio frequency beam using the position of the DUT30and the direction of the beam56in a 3D-coorindate system being defined by the set of markers321to323. This expected location may be used as value or set of values against which the measurement data is compared for evaluating the DUT30. The method may be implemented such that the determining the position of the DUT comprises holding the DUT30with the structure and detecting a position of the set of markers321to323at the DUT30and determining the position of the DUT within the measurement environment31using the position of the set of markers321to323in the measurement environment31.

According to embodiments, knowledge of the CORRP is be combined with knowledge of a geometric feature of the DUT30, i.e., the markers321to323. Through the combination of these two pieces of information, the reference point CORRP52and a reference direction of a beam may be determined. To determine the direction a minimum of either three points, or a single point combined with a plane and/or edges and/or corners and/or fixed features may be used. Thus, a position of the DUT30may be determined using the set of markers321to323. An expected location or a nominal value of a location where the DUT is expected to form the beam may be determined using the position of the DUT30and the direction information received. This may be done using the 3D-coorindate system being defined by the set of markers32which may be identical to or at least transferable from the 3D coordinate system36.

FIG.3cis a schematic diagram illustrating a schedule of resource elements37in a wireless communications network in a time/frequency plane.

FIG.3dshows a schematic diagram of beams561and562that may be formed with antenna arrays441and442operating according to the schedule ofFIG.3c. Resource elements371shaded from the upper left to the lower right may be used to form the beam561with the antenna array441, wherein resource elements372shaded from the upper right to the lower left may be used to form the beam562with the antenna array442. Common resource elements373being cross-shaded, be used by both antenna arrays441and442, for example, to transmit common control messages. With respect to the resource elements373, the beams561and562may have the same pattern in the time/frequency space. For example, inFIG.3d, by a superpositioning of the beams561and562, a common beam563may be formed based on a use of the common resource elements373. This beam563may have the virtual reference origin543which may be referenced or determined with respect to the CORR. The virtual reference origin may be arranged, for example, between the (real) reference origins541and542of beams561and562. The virtual reference origin543may be placed in a symmetry plane with respect to the beams561and562.

Thus, the DUT may form a plurality of beams. The first beam561is formable with the first antenna array441and the second beam562is formable with the second antenna array442, wherein the first and second beams at least partially comprise a common pattern in a time and frequency space and thereby form a third beam563comprising a reference origin543being arranged spaced from the reference origin541of the first beam561and the reference origin542of the second beam562. Based on a varying power of at least one beam561and/or562a varying relationship of powers between the beams, an orientation of the beam563may be changed.

Embodiments relate to a DUT that may comprise one or more antenna arrays and/or wherein at least one of the antenna arrays comprises itself a number of subarrays, the number being any number greater than one.

For example, the antenna arrays or subarrays may be arranged in a tiled structure. Such a structure may be referred to as an arrangement of antenna panels, wherein each antenna panel may be a functional unit of an antenna array or subarray. Each of these panels may be designed so as to form one or more beams for transmission and/or reception purposes. Further, a combined beam may be formed using at least two beams of a single panel and/or of different panels.

These embodiments may apply to arbitrary arrangements of panels and sub-panels, examples of which could include both regular and irregular tiling schemes. In view of the DUT, the wireless interface of the DUT may comprise a plurality of antenna subarrays, each subarray configured for forming at least a portion a beam pattern, combined beam or the like.

According to an embodiment, for each subarray a CORR may be defined. Alternatively or in addition, a CORR may be defined for at least one combined beam being formed by a single subarray or a combination of subarrays. Defining a CORR for a single subarray or for each subarray may allow for a simple evaluation of beams formed with the subarrays, wherein defining a CORR being based on at least a first and a second subarray may allow for a simple evaluation of combined beams of the DUT. It is noted that one solution is combinable, without limitation, with the other, i.e., CORR may be defined for a subarray and for a combination thereof at a same time.

FIG.3eis a schematic diagram of a use case according to present embodiments. An example cross-section of a beam56may be evaluated using different conformance/measurement points571to574being arranged around a symmetry point, axis or plane59indicating a symmetry of the beam56. The angles ϕ and Θ denote the elevation and azimuth directions relating to the beam and the respective antenna array(s). The symmetry point, axis or plane59may form a center for measurements in connection with an error vector magnitude (EVM), i.e., a center of EVM directions range. A plane61may be formed according to declarations with respect to an OTA EVM direction range, i.e., an area of the cross-section that has to be evaluated. This area may depend on a distance with respect to the point of origin, and may increase for a defocused beam or decrease for a focused beam. Knowing point, axis or plane59may thus allow for positioning the points57and to evaluate the beam56. According to embodiments, the point, axis or plane59may be defined as CORR and the points57may be used as measurement points.

FIG.4ais a schematic flowchart of a method400that may be implemented for determining a location information, for example, during the step120. In a step410, a set of beams formable with the DUT is defined. For example, the set of beams may include the beam561,562and/or563.

A step420comprises determining, for each of the beams within the set of beams, an offset of a reference origin of the beam with respect to the CORRP and a directional deviation of a beam direction with respect to a reference direction, such that the location information allows it to indicate the reference origin and the beam direction with respect to the CORRP. The offset of the reference origin, e.g., reference origins541,542and/or543, may be a position of the respective reference origin within the 3D coordinate system36. The offset may thus relate to an offset of the respective reference origin with respect to the center of origin38and/or a position in the measurement environment. The deviation in the reference direction may relate to a direction within the coordinate system36. The reference direction may be, for example, a direction along one or more of the axes and/or directions within coordinate system. Any direction within the coordinate system36may be used as reference direction such that the directions581,582and583indicate a direction of the respective beam541,542and/or543within the 3D coordinate system36.

In other words, the CORRP may be described by four points (three reference markers and the center of origin of the coordinate system) and three axes which may be perpendicular axes, and at least span a 3D space.

The CORRP and/or location information may be provided as a reference point/vector set in a three-dimensional space which allow for determination of a relative and axial position and description in space, especially of i) a point and/area where the waves (beams) are emitted from, ii) point and/or areas where distributed antennas are positioned; iii) point and/or areas of a superpositioned/effective antennas/antenna-arrays which emit radio waves; and/or iv) indicate polarization effects. Point ii) does not necessarily comprise to define a position of antennas, although it is possible. Manufacturers may use the invented reference point CORRP rather than reveal the location of the antenna(s) within a device. Thus, the exact antenna/antenna array location may but is not required to be revealed by the description of the CORRP but allows for a rather more general location where the beam pattern seems to originate from. Of course it could be an antenna location in itself. Furthermore, when a device comprises a number of antennas or a number of antenna arrays, the specification of the location of same may be tedious and could result in misinterpretation which in turn might affect accuracy. Therefore a single CORRP for each device, regardless of the number of antennas it contains, provides advantages in terms of keeping details of the device undisclosed, in enhancing accuracy of the measurements and/or in effectively defining a measurement environment.

Relative to the CORRP pointing vectors may be defined in order to relate the antenna array, the beam respectively with the CORRP. This may include a) a point of origin of emitted radiation and/or b) a relative coordinate system to describe i) a positioning of an array surface 3D space; ii) directions of emissions, such as, the directions58, and/or iii) a reference point and vectors for emission. The reference points or reference markers may be accessible from the outside of the device or relative to specific markers or device specific boundaries of the device, e.g., faces, planes, corners, edges or the like. Thus, the set of reference markers may also include corners or edges of DUT housing.

As shown inFIG.4b, similar to defining the 3-dimensional orientation information, defining the CORR may comprise the step410, i.e., defining a set of electromagnetic wave patterns formable with the DUT, the set of electromagnetic wave patterns including the electromagnetic wave pattern. Further, for each of the electromagnetic wave patterns within the set of electromagnetic wave patterns, an offset of the reference origin of the electromagnetic wave pattern with respect to the CORR may be determined in a step460.

FIG.5ais a schematic flowchart of a method500that may be used for exploiting the information relating to the CORRP and/or the location information. An optional step510comprises determining a position of the DUT using a set of markers of the DUT, e.g., the markers321to323as described, for example, in connection withFIG.3b. An optional step520comprises determining an expected location for the radio frequency beam using the position of the DUT and the direction of the beam in a 3D-coorindate system being defined by the set of markers. A step530comprises detecting a radio frequency beam from a DUT. The radio frequency beam may be, for example, a receiver beam and/or a transmit beam. A step540comprises receiving information indicating a Center-of-Radiation Reference (CORR) for a DUT, the CORR indicating a reference origin of an electromagnetic wave pattern formed with the DUT. The step540comprises receiving a 3-dimensional orientation information with respect to the CORR, the 3-dimensional orientation information indicating a direction of the electromagnetic wave pattern. A step550comprises evaluating the detected radio frequency beam with respect to a match with the CORRP and the location information. An order of performing steps530and540may be arbitrary. I.e., step530may be performed before, after or even simultaneously with step540. The step550may comprise certain evaluation steps, for example, if the beam characterized by the location information matches with the radio frequency beam detected from the DUT. Such a match may comprise a match of the reference origin and/or a match of a physical extension of main lobes and/or side lobes but is not limited hereto. The electromagnetic wave pattern may be a 3D-pattern of the radiation and may be formed arbitrary. Such a 3D pattern may include information relating to main lobes and/or side lobes, for example, when the electromagnetic wave pattern comprises a beam. The 3D pattern may not suitably be described by terms of main lobe or side lobe, for example, when having large opening angles in elevation and/or azimuth direction. The 3D-pattern may be any formed or shaped radiated beam pattern/field which can be described relatively to a given CORRP and direction.

The location information may comprise information indicating at least one main lobe for the beam and/or at least one side lobe of the beam. Such information may comprise an angular formation where, i.e., with reference to the CORRP and/or the reference origin and/or along which direction a respective main lobe or side lobe extends within the beam. Evaluating the detected radio frequency beam, for example, when performing step550, may comprise an evaluation of the detected radio frequency beam with respect to the at least one main lobe of the beam and/or the at least one side lobe of the beam. An order of the steps510and/or520, when performed, may be independent from an execution of steps530and/or540, i.e., it may be sufficient to implement the steps510,520,530and540as far as executed before executing step550. As explained before, the electromagnetic wave pattern is not limited to beams. When, for example, the CORRP and the reference direction for the description of a radiated beam pattern is provided, the exact shape of the pattern may be arbitrary and does not require the definition of one or several main lobes or side lobes. A description of such particular features towards specific directions in three dimensions may be implemented in some embodiments but may relate to more general features of the 3D electromagnetic wave pattern.

FIG.5bshows a schematic flow chart of a method560that may be implemented, for example as part of step510, when performed. A step570comprises holding the DUT with a structure of a measurement environment such as the structure35of the measurement environment31. A step580comprises detecting a position of the set of markers such as the markers321to323at the DUT. A step590comprises determining the position of the DUT within the measurement environment using the position of the set of markers in the measurement environment.

FIG.6is a schematic flow chart of a method600that may be performed together with method500, for example, responsive to results of step550. In a step610a position of the DUT is adjusted such that the reference origin of the beam forms a center of the measurement environment that is used for detecting and/or evaluating the radio frequency beam. Alternatively or in addition step620may be performed in which a misalignment between a predetermined center of the measurement environment and the reference origin of the radio frequency beam may be determined. A result of the evaluating of the detected radio frequency beam may be corrected, using the determined misalignment.

I.e., the results of step550may be corrected. For example, when the measurement indicates that a reference origin of the detected radio frequency beam is at a different location as indicated in the location information, the DUT may be shifted with respect to the probes, i.e., the probes and/or the DUT may be moved so as to allow for a precise categorization of the radio frequency beam. Alternatively or in addition, the detected misalignment may be considered in the results.

Using steps610,620respectively, in case of misalignments and knowledge about the CORRP for two different beams at the same or different frequency the resulting deviations might be used to post-compensate (610) the misalignment or pre-compensate iteratively before repeating the measurement. (620)

As described above, the detection of the radio frequency beam may relate to detecting (receiving) the beam from the DUT and/or detecting the beam with the DUT when receiving the radio frequency beam by use of the DUT.

FIG.7is a schematic block diagram of a device or apparatus70that may be used as a device under test according an embodiment. The apparatus70may comprise a display62and an interface64. The interface64may be configured to receive a signal66indicating a request that the apparatus70is requested to perform a test mode. The interface64may be, for example, a wireless communication interface, such as an interface comprising an antenna or an antenna array. In this case, the signal66may be a wireless signal. The apparatus70is configured to switch to the test mode responsive to the signal66and to display a predefined optical signal pattern68with the display. The optical signal pattern may comprise one or more pictures and/or points and/or dots that may be used as a number of 1, 2, 3 or more reference markers321and/or322and/or323. I.e., the optical signal pattern68provides at least a part of a set of reference markers at the apparatus70. When referring again to the DUT30, it may be seen that at least one of the reference markers321,322and/or323may be implemented by respective parts or portions of the optical signal pattern68. The apparatus70may be configured to display the optical signal pattern independently from a user input indicating a change of displaying the optical signal pattern. Such a user input may be, for example, a request to vary a size of the pattern, a position of the pattern in the display62and/or a request to display a different pattern. Thus, the optical signal pattern68may be immobile with respect to a housing of the apparatus70and may thus act as a reference marker. For example, the optical signal pattern may be a barcode of one or more dimensions including a matrix barcode for example a Quick Response (QR) code or a matrix barcode or a different two-dimensional code. A QR-code may provide for a high density of information to be displayed. This may be of advantage from, especially, when a number of beams is evaluated during a test. A specific optical signal pattern68may be associated with a respective beam and/or test mode. Thereby, the optical signal pattern may indicate the respective beam and/or test mode such that the apparatus70indicates a beam that is actually formed with the apparatus. The apparatus70may configured to subsequently switch on one of a plurality of test modes and/or beams or combinations thereof and to subsequently display one of a plurality of optical signal patterns. Each of the displayed optical signal patterns may be associated with the respective current test mode performed with the apparatus70.

FIG.8ais a schematic block diagram of a measurement system80according an embodiment. The measurement system80is configured to perform one or more of the methods described herein. For example, the measurement system80is configured to perform method500and/or600. Optionally, the measurement system80may be configured to further perform at least one of the methods100,200and/or400. The measurement system80may comprise a plurality of probes721to725. One or more probes may be configured to evaluate the beam56in a near field, for example, the probes721. One or more probes may be configured to evaluate the beam56in a mid-field, for example the probe722. One or more probes may be configured to evaluate the beam56in a far field of the beam56, for example, the probes723,724and/or725.

The measurement system18may be configured to evaluate a DUT, for example, apparatus30and/or70. The location information obtained and used with the measurement18may comprise information indicating the reference origin541of the beam561. The location information may comprise information indicating reference origins541and542of the respective beams561and562. The location information may further comprise information relating to a direction581and582of the respective beam. The measurement system may be configured for evaluating the detected radio frequency beam561and/or562with respect to a match of a superpositioned with the beam561and562. As described in connection withFIG.3, a summarized beam may be obtained by a superposition of single beams561and562and/or further beams. The measurement system18may comprise a control unit and/or an evaluating unit that is configured to evaluate the results obtained by the DUT (evaluating a receive beam) and/or the probes721to725(transmit beams).

When detecting beams561and/or562and/or a superposition of the beams in the near field of the beam, the measurement system18may be configured through extrapolate a characteristic of the beam in a far field of the beam. Based on a precise knowledge of the beam to be evaluated, i.e., the reference origin and the direction with respect to the CORRP, such extrapolation may be performed with a high precision.

FIG.8bis a schematic block diagram of a measurement system80′ comprising a measurement chamber housing a plurality of probes721to726that may be arranged in the near field (NF), the mid-field (MF) and/or the far field (FF). One or more probes, for example, probe721, may be movable within the measurement chamber74. Alternatively or in addition, one or more of the evaluated DUTs, for example, the DUT70may be movable within the measurement chamber74so as to allow side lobes761to764and/or main lobes781to783to vary with respect to the position and/or orientation relative to the probes721to726.

In other words, when using OTA measurement for characterization of, e.g., beams patterns it may be very important to know the exact reference point (source; reference origin) where the beam originates from. This may become even more important, if the OTA measurements are taking place in a near field or the DUT has large dimensions, for example, when being a car. Furthermore, when using high radio frequencies like e.g. millimeter waves at e.g. 28 GHZ, 39 GHz, 60 GHz and 7 or above the wavelength becomes very short an inaccuracies in nearfield measurements may cause rather large errors for the calculated far field pattern after transformation if the exact CORRP for an emitted beam is unknown. Another case may be provided from compact form factor devices like smart phones, tablets or laptops where either the exact location of the antennas is not known from the outside and/or when the device uses several antennas distributed across the device. In all of these cases, it may be crucial to know the reference point in order to evaluate the measured beam patterns accurately. Embodiments described herein introduce a 3D referencing scheme that allows to describe the referencing origin for every beam created by the DUT using the CORRP. Embodiments provide a solution to determine the reference point of every beam emitted correctly, especially from the outside of the device. This becomes evident if antennas and/or antenna arrays are distributed over a relatively large object like a car or the like which is positioned in a measurement setup/system during a measurement procedure to determine, e.g., a 3D radiated beam pattern around a DUT, it is known to mount a DUT in a measurement system on a holder surrounded by one or a multiple sensors at a certain distance (near field, mid field or far field) to measure specific parameters like power, phase, phase stability or the like. In order to scan the radiated pattern in 3D, either the DUT is rotated, shifted or moved such that the sensor observes the DUT under another observation angle or the sensor(s) around DUT at given distances. Alternatively, the two movements could be overlaid to have a 3D field scan. As illustrated for DUT70inFIG.8b, the same may be mounted on a rotator to move the DUT. In the ideal case of a point like emitters, e.g., a wire as Hertzian dipole rotation about the wire center, the measure radiated pattern may result in a vary symmetric circular shape. In case of miss-position of the wire against the rotation center, a distorted radiation pattern may be observed, which can be easily compensated when the CORRP is known and considered during the measurement. The CORRP may comprise information relatively to the rotation center. Such compensation procedure could be performed after the measurements or, if possible, the movement may be pre-compensated such that the effective rotations axis falls aligned with the center of emission in the antenna already.

FIG.9ashows a schematic diagram illustrating an effect of missing knowledge about the Center-of-Radiation Reference Point when a DUT is mounted within a sensor environment, i.e., a measurement system, for, e.g., radiated pattern measurements. A shift of the DUT along a direction82may lead to a shift of the main lobe78and/or other lobes emitted. By determining the beam and/or lobes with the probes72, it may be difficult or impossible to determine, if this is a malfunction of the DUT and/or an effect caused by the misalignment, especially when the desired and/or actual position of antenna arrays is not known.

Example DUTs may be, for example, active antenna systems (AAS), base station antennas, user equipment such as a handset, a laptop, a vehicle a drone, an extended large size object like a leaky feeder cable or the like.

FIG.9bshows a schematic diagram illustrating a structure of the antenna array44. The antenna array44may comprise a plurality of antenna elements841to84N. The CORRP may be used stand-alone or in combination with all information/instructions such as a request to align a specific component such as a probe, the DUT or another element with an edge of a device and/or to align a sensor perpendicular to a screen or a surface displaying the reference point on the display showing the test pattern. As illustrated, a shift82′ that may be inverse to the shift82ofFIG.9amay be implemented so as to align the DUT, e.g., the DUT70, with one or more probes72. This allows to exactly determine the side lobe76and/or the main lobe78of a beam. For example, a measurement system may use a search algorithm, e.g., in connection with a probe. When a respective marker or pattern may be observed with the probe72, an alignment may be assumed and the CORRP may be used to determine whether the detected or determined beam matches the desired condition. This may be done using a search algorithm for aligning the DUT.

The embodiments described herein may be executed together, but may also allow for a distributed implementation. For example, a manufacturer of a device or DUT may perform one or more of the methods100,200and/or400. Thereby, a manufacturer may provide a reference point and/or reference points/vectors for each beam and/or beam sets supported by the device. This may include information in connection with one or more main lobes and/or one or more side lobes. The manufacturer further may provide information relating to frequencies or frequency ranges for transmission/reception for each of the beams. Each mode or sets of transmit modes may be indicated to be used for forming a specific beam. In specific modes, different antennas/antenna elements may be involved in the beam creation. Thereby, by indicating specific details on the antennas or antenna elements used, further details may be evaluated within the test.

The measurement system using the CORRP and/or the location information and/or implementing one or more of the methods500and600may include a DUT holder (carrier) and may be configured to offset the mounted DUT in 3D coordinates using vectors such that the reference point is centered through the usual measurement procedure (step610) and/or the known misalignment is incorporated in correction of functions/transformations for the beam pattern evaluations (step620).

The respective reference point may be a physical marker on the device or relative to corner stones and/or edges. This may include any kind of options on how to reference, e.g., to a plane, corner, edge, barcode, e.g. matrix barcodes such as QR-codes (defined in a plane and may have a size that is predetermined, etc. and that may be used as a reference for a coordinate system). A defining or marking of the CORRP may be done using the QR-code that may contain additional information such as information relating to values that may be bound/restricted to reasonable physical constraints. A one-dimensional or two-dimensional barcode such as a QR-code may be, implemented permanently, for example, using a printing, etching engraving, adhering step or the like so as to attach the code to the case, body, housing, cover cowling, enclosure and/or a radom of a DUT. Alternatively, such a code may be displayed on the screen of a UE when the UE is configured into a certain mode of operation that is convenient for measurement purposes. The position of the QR-code in all instances may be fixed. The QR-code itself may be read by a machine reading device such as a scanner or reader, e.g., by the device33. Such a device may reads the information contained in the QR code and/or may be configured to determine the position of the QR-code on the DUT. Contained within the QR-code data, is in this case information that is used by the reader to determine the CORRP. In other words, the QR-code can be positioned in such a location that is convenient, practical, acceptable and/or aesthetic and does not form a marking of the CORRP itself per se. Furthermore, the QR code could define a physical feature at the outside of the DUT and a description on how to derive the CORRP relative to this marker by e.g. providing this information from a data base which can be a priori known or updated over time. Such information may be retrieved, for example, from accessing a website or other explicitly referenced source of information. At such source the content can be held available for download/access in an unchanged or changeable way ready to be updated if needed. Furthermore, such information set might have a version number to be referred to, when conducting the measurement in the sense: “such measurement on the DUT was performed according to measurement instruction ABC version 1.23” or the like.

Alternatively or in addition, the CORRP may be defined based on a mechanical marking such as a notch, an etching or a hole. Alternatively or in addition, a so-called badge marking may be implemented so as to obtain a sweet spot. Alternatively or in addition, a matrix code such as a QR-code may be displayed in the test mode and thereby use a user equipment screen (display) using dedicated pixel positions with the optical pattern. Alternatively or in addition, a lamp/camera lens/microphone, speaker or the like of the user equipment may be used as CORRP.

The embodiments described herein may allow for exactly referencing of where the waves/beams originally are omitted from. The embodiments allow to keep a nondisclosure of device-specific technical solutions by the manufacturer as it may be sufficient to define the CORRP and the location information. Embodiments may allow for a proper positioning of the device relative to the outer reference points visible/accessible at the device. Embodiments may allow for a correct transformation from near field to far field even with misaligned or distributed antennas as their behavior may be evaluated correctly with high precision. Symmetries in the beams may be identified more easily based on a correct determination of the reference origins and/or patterns of the beams. A measurement site or house, e.g., a laboratory, may use exactly the same reference point as the manufacturer without opening or destroying the DUT, using the CORRP. Embodiments described herein allow to define/use different reference points for combinations of antennas/arrays, etc. In a communication system, the proposed embodiments may be reused to ease functionality like a beam paring, i.e., CORRP may be used stand-alone and/or in combination with other methods such as search algorithms.

Alternatively or in addition, a beam coordination may be performed, e.g., when using several antenna arrays pointing along arbitrary directions. Embodiments offer a precise method for OTA measurement of the DUT radiation patterns which allows a standardized and fair comparison (benchmarking) to other peer devices or products.

Although some aspects have been described in the context of an apparatus, it is clear that these aspects also represent a description of the corresponding method, where a block or device corresponds to a method step or a feature of a method step. Analogously, aspects described in the context of a method step also represent a description of a corresponding block or item or feature of a corresponding apparatus.

Depending on certain implementation requirements, embodiments of the invention can be implemented in hardware or in software. The implementation can be performed using a digital storage medium, for example a floppy disk, a DVD, a CD, a ROM, a PROM, an EPROM, an EEPROM or a FLASH memory, having electronically readable control signals stored thereon, which cooperate (or are capable of cooperating) with a programmable computer system such that the respective method is performed.

Some embodiments according to the invention comprise a data carrier having electronically readable control signals, which are capable of cooperating with a programmable computer system, such that one of the methods described herein is performed.

Generally, embodiments of the present invention can be implemented as a computer program product with a program code, the program code being operative for performing one of the methods when the computer program product runs on a computer. The program code may for example be stored on a machine readable carrier.

Other embodiments comprise the computer program for performing one of the methods described herein, stored on a machine readable carrier.

In other words, an embodiment of the inventive method is, therefore, a computer program having a program code for performing one of the methods described herein, when the computer program runs on a computer.

A further embodiment of the inventive methods is, therefore, a data carrier (or a digital storage medium, or a computer-readable medium) comprising, recorded thereon, the computer program for performing one of the methods described herein.

A further embodiment of the inventive method is, therefore, a data stream or a sequence of signals representing the computer program for performing one of the methods described herein. The data stream or the sequence of signals may for example be configured to be transferred via a data communication connection, for example via the Internet.

A further embodiment comprises a processing means, for example a computer, or a programmable logic device, configured to or adapted to perform one of the methods described herein.

A further embodiment comprises a computer having installed thereon the computer program for performing one of the methods described herein.

In some embodiments, a programmable logic device (for example a field programmable gate array) may be used to perform some or all of the functionalities of the methods described herein. In some embodiments, a field programmable gate array may cooperate with a microprocessor in order to perform one of the methods described herein. Generally, the methods may be performed by any hardware apparatus.

While this invention has been described in terms of several embodiments, there are alterations, permutations, and equivalents which fall within the scope of this invention. It should also be noted that there are many alternative ways of implementing the methods and compositions of the present invention. It is therefore intended that the following appended claims be interpreted as including all such alterations, permutations and equivalents as fall within the true spirit and scope of the present invention.

REFERENCES

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