Method and network node for over-the-air testing of active antenna systems

Abstract

A mechanism for OTA testing of AAS of a EUT is provided. The method is performed by a network node. The method comprises obtaining a definition of a test signal to be transmitted or received by the EUT according to a time / frequency resource grid. The method comprises applying first beamforming weights to first selected resource elements of the time / frequency resource grid giving first beam directions according to a first type configuration for a first OTA test of the AAS. The method comprises applying second beamforming weights to second selected resource elements of the time / frequency resource grid giving second beam directions according to a second type configuration for a second OTA test of the AAS. The method comprises initiating transmission or reception of the test signal on the AAS using the time / frequency resource grid.

Description

Technical Field

[0001] The embodiments presented herein relate to methods, network nodes, computer programs, and computer program products for over-the-air (OTA) testing of an active antenna system (AAS) for a device under test (EUT). Background Technology

[0002] AAS is a term used to describe radio base stations or other types of access network nodes that contain a large number of individual transmitter and antenna elements as an integrated product, which can be used for multiple-input multiple-output (MIMO) communication and beamforming. Transmissions from access network nodes are expected to occur at higher frequency bands currently in use. At such high frequency bands, such as in microwave or millimeter-wave regions, propagation loss is greater than in currently used bands. Therefore, beamforming may be necessary to achieve the link budget required for high data rates.

[0003] In access network nodes equipped with AAS, physical access to the Antenna Reference Point (ARP) (also known as the Transceiver Array Boundary (TAB)) will be restricted or unavailable. Therefore, it will be impossible to perform measurements found in conformance testing requirements included in traditional specifications (e.g., those specified in the following 3GPP publications: 3GPP TS 25.141, 3GPP TS 36.141, 3GPP TS 37.141, and 3GPP TS 37.145-1). Therefore, OTA testing may be the only method to verify RF characteristics such as radiated transmit power and radiated unwanted emissions.

[0004] In 3GPP TS 37.145-2, Release 13 (Rel-13), a limited number of OTA requirements (radiated emission power and OTA sensitivity) have been introduced. Releases 15 (Rel-15) of 3GPP TS 37.145-2 and 3GPP TS 38.141-2 contain complete OTA test specifications for frequency regions FR1 (430 MHz to 7125 MHz) and FR2 (24 to 52 GHz). From a practical perspective, FR1 is generally divided into two sub-ranges called the Low Band (LB) and Mid Band (MB), and FR2 is called the High Band (HB). This means that RF parameters need to be tested under normal environmental conditions, with some requirements specified for testing under extreme environmental conditions. Specific parameters, such as the currently measured radiated emission power, radiated unwanted emissions, OTA sensitivity, and frequency stability, will have to be measured via OTA. When performing OTA testing, the absolute radiated power will correspond to the equivalent isotropic radiated power (EIRP), and the absolute received power will correspond to the equivalent isotropic sensitivity (EIS).

[0005] The conditions available for normal and extreme conditions are defined by 3GPP in 3GPP TS 37.145-2 and 3GPP TS 38.141-2. Based on design quality assurance and other requirements, the scope of extreme conditions can be extended to include vibration and extreme power characteristics when testing RF characteristics. For receiver sensitivity, there are no specific regulatory requirements for measurement during extreme conditions, but it is expected that customers will request this information. In some geographic regions or jurisdictions, regulators define receiver requirements that indirectly include the receiver sensitivity to be measured.

[0006] Current specifications from RAN4 (Radio Access Network Working Group, Radio Performance and Protocol Aspects) related to base station RF core requirements and conformance testing requirements have defined the concept of test space characteristics for downlink (DL) and uplink (UL). The concept of capturing space characteristics is established around a set of EIRP and EIS declarations for a set of directions. The exact direction and the actual EIRP or EIS are declared by the manufacturer and are unique for a specific access network node implementation. "Pass and fail" criteria are defined to ensure that the declared EIRP or EIS is met within the measurement uncertainties given in 3GPP TS 37.145-2 for Multi-Standard Radio (MSR) and 3GPP TS 38.141-2 for New Radio (NR). During the specified OTA conformance testing, specified test signals (for DL ​​test models and UL fixed reference channels) are used. The specified test signals define the actual signals to be used during testing in the frequency and time domains. However, the spatial aspect of being able to generate different beam directions during testing is not specified. In order to meet the requirements of 3GPP TS 37.145-2 and 3GPP TS 38.141-2, access network node manufacturers must be able to apply test beamforming weight vectors associated with the declared beam direction (described in sub-clause 4.10 of 3GPP TS 37.145-2 and sub-clause 4.6 of 3GPP TS 38.141-2).

[0007] The minimum range of beam directions to be tested in 3GPP TS 37.145-2 and 3GPP TS 38.141-2.

[0008] Unlike the conformance test specifications for user equipment (as given in 3GPP TS 38.521), the conformance test specifications for access network nodes (as given in 3GPP TS 38.141-1 and TS 38.141-2) do not specify any test interfaces, i.e., any interfaces for applications that inject or control test signals. Currently, only test signals and test conditions are specified for RF requirements. Test models are defined in subclause 4.12.2 of 3GPP TS 37.145-2 and subclause 4.9.2 of 3GPP TS 38.141-2.

[0009] However, the capabilities of radio and antenna hardware and software are becoming increasingly advanced with each new 3GPP release. For example, in NR (5G), waveforms are more flexible, and support for active antennas (systems) has been added, increasing the need for more advanced test interfaces. Furthermore, recommendations for new test capabilities have been proposed in other forums, such as the Open RAN (O-RAN) Alliance and the Next Generation Mobile Network (NGMN) Alliance. For NR, the testing concepts used for Long Term Evolution (LTE) have been retained. However, new test capabilities, methods, and interfaces are needed to be able to test OTA requirements for NR.

[0010] Therefore, OTA testing for AAS still needs improvement. Summary of the Invention

[0011] The purpose of the embodiments in this paper is to address the above-mentioned problems by providing a technique for OTA testing of AAS that is efficient in terms of implementation complexity and time constraints.

[0012] According to a first aspect, a method for OTA testing of an EUT's AAS is proposed. This method is performed by a network node. The method includes obtaining a definition of a test signal to be transmitted or received by the EUT according to a time / frequency resource grid. The method includes applying a first beamforming weight to a first selected resource element of the time / frequency resource grid, giving a first beam direction, according to a first type configuration for a first OTA test of the AAS. The method includes applying a second beamforming weight to a second selected resource element of the time / frequency resource grid, giving a second beam direction, according to a second type configuration for a second OTA test of the AAS. The method includes initiating the transmission or reception of the test signal on the AAS using the time / frequency resource grid.

[0013] According to a second aspect, a network node for OTA testing of an EUT's AAS is proposed. The network node includes processing circuitry. The processing circuitry is configured to enable the network node to obtain a definition of a test signal to be transmitted or received by the EUT according to a time / frequency resource grid. The processing circuitry is configured to enable the network node to apply a first beamforming weight to a first selected resource element of the time / frequency resource grid, giving a first beam direction, according to a first type configuration for a first OTA test of the AAS. The processing circuitry is configured to enable the network node to apply a second beamforming weight to a second selected resource element of the time / frequency resource grid, giving a second beam direction, according to a second type configuration for a second OTA test of the AAS. The processing circuitry is configured to enable the network node to initiate the transmission or reception of test signals on the AAS using the time / frequency resource grid.

[0014] According to a third aspect, a network node for OTA testing of EUT's AAS is proposed. The network node includes an acquisition module configured to acquire the definition of a test signal to be transmitted or received by the EUT according to a time / frequency resource grid. The network node includes an application module configured to apply a first beamforming weight to a first selected resource element of the time / frequency resource grid, giving a first beam direction, according to a first type configuration for a first OTA test of AAS. The network node includes an application module configured to apply a second beamforming weight to a second selected resource element of the time / frequency resource grid, giving a second beam direction, according to a second type configuration for a second OTA test of AAS. The network node includes an initiation module configured to initiate the transmission or reception of the test signal on the AAS using the time / frequency resource grid.

[0015] According to the fourth aspect, a computer program for OTA testing of EUT's AAS is proposed, the computer program containing computer program code that, when run on a network node, causes the network node to execute the method according to the first aspect.

[0016] According to the fifth aspect, a computer program product is proposed, comprising a computer program according to the fourth aspect and a computer-readable storage medium storing the computer program. The computer-readable storage medium may be a non-transitory computer-readable storage medium.

[0017] Advantageously, these aspects provide OTA testing for AAS that is effective in terms of implementation complexity and time constraints.

[0018] Advantageously, these aspects enable a significant reduction in test time for AAS system testing. Currently, there are some limitations on the number of beams for each measurement. These are primarily instrument-side constraints, but the proposed aspects are not limited by a maximum number of beams. Test model modes can typically be extended to more than one radio frame.

[0019] Advantageously, including several beams in the same test signal makes it possible to measure parameters that require phase relationships (such as orthogonality) and changes between beams (i.e., transient beam behavior).

[0020] Advantageously, these aspects enable AAS to be tested in a way that is more closely related to its actual operation, rather than applying custom beamforming weights to the beamform.

[0021] Advantageously, regardless of the base station type (BS 1-C, BS 1-H, BS 1-O and BS 2-O) specified in subclause 4.6 of 3GPP TS 38.104, these aspects enable the testing of spatial characteristics.

[0022] Advantageously, regardless of the beamforming technique used (analog, digital, or hybrid beamforming), these aspects enable the testing of spatial characteristics.

[0023] Advantageously, these aspects enable improved overall accuracy of the test by reducing the risk of factors such as temperature drifting over time.

[0024] Other objects, features, and advantages of the appended embodiments will become apparent from the following detailed disclosure, the appended dependent claims, and the accompanying drawings.

[0025] Generally, all terms used in the claims shall be interpreted in accordance with their ordinary meaning in the technical field, unless otherwise expressly stated herein. Unless otherwise expressly stated, all references to “a / an / the element, device, component, means, module, step, etc.” shall be openly interpreted as referring to at least one instance of the element, device, component, means, module, step, etc. Unless expressly stated otherwise, the steps of any method disclosed herein need not be performed in the exact order disclosed. Attached Figure Description

[0026] The inventive concept will now be described by way of example, with reference to the accompanying drawings, wherein: Figure 1 The example illustrates a time / frequency resource grid 100. Figure 2 This is a block diagram of the system according to an embodiment; Figure 3 This is a flowchart of the method according to an embodiment; Figures 4 to 8 This is a block diagram illustrating the implementation of the network node and EUT according to an embodiment; Figure 9 This is a flowchart of the method according to an embodiment; Figure 10 The following is illustrated in the form of a block diagram to show how the example is executed. K OTA tests with different configurations; Figure 11 The diagram illustrates how to perform actions for one or more EUTs, based on the example. M Analysis of different antenna patterns; Figure 12 This is a schematic diagram illustrating the functional units of a network node according to an embodiment; Figure 13 This is a schematic diagram illustrating the functional modules of a network node according to an embodiment; Figure 14 An example of a computer program product including a computer-readable storage medium according to an embodiment is shown; Figure 15 This is a schematic diagram illustrating a telecommunications network connected to a host via an intermediate network according to some embodiments; Figure 16 This is a schematic diagram illustrating how a host computer, according to some embodiments, communicates with a terminal device via a radio base station over a partial wireless connection. Detailed Implementation

[0027] The concept of the invention will now be described more fully below with reference to the accompanying drawings, in which certain embodiments of the concept of the invention are illustrated. However, the concept of the invention may be embodied in many different forms and should not be construed as limiting to the embodiments described herein; rather, these embodiments are provided by way of example so that this disclosure is thorough and complete and will fully convey the scope of the concept of the invention to those skilled in the art. Throughout the description, similar numbers refer to similar elements. Any step or feature indicated by dashed lines should be considered optional.

[0028] As mentioned above, OTA testing for AAS still needs improvement.

[0029] Furthermore, testing current multibeam systems is extremely time-consuming because testing must be performed beam-by-beam. Each set of beamforming weights needs to be loaded sequentially, which takes a significant amount of time. This time is largely due to the communication of the beamforming weights between the device under test (DUT) and any control units, and any possible transfers. This typically involves multiple commands that need to be communicated back and forth between the DUT and the control units.

[0030] Furthermore, depending on the device under test, the carrier may need to be restarted, and / or calibration may be affected. This means that it is necessary to ensure that the AAS is phase-aligned before proceeding. Considering that multiple beams and angles are to be measured, the time for updating beamforming weights is likely to be a major contributor to the total time.

[0031] Along with the aforementioned time constraints, some AAS functions remain untested, such as ensuring that changes between beams occur within the allocated time (transient beam behavior), and the AAS's ability to generate different beams without carrier teardown.

[0032] Some antenna system parameters (such as orthogonality) cannot be tested using existing techniques because it requires measuring both the amplitude and phase data of certain baseband channels (“signals”).

[0033] Furthermore, there are mechanical limitations to the movement of the tested equipment between angles. These limitations can currently only be improved before mechanical failures or greater uncertainties are introduced.

[0034] Using the beamforming weight loading time mentioned earlier, it is generally best to physically move the device under test to all locations before loading new beamforming weights. Therefore, when performing tests beam-by-beam, the movement of the device under test will always account for a significant portion of the test time.

[0035] As an illustrative example, assume the parameter values ​​are as shown in Table 1:

[0036] Table 1: Parameters and values ​​used for testing

[0037] ( The movement time refers to the movement of the device under test from one angle to the next, excluding the communication time between the device under test and the control unit, and can be expressed as:

[0038] ( Assuming a step size of 1 degree, a single cut.

[0039] The total time to test all 360 beams is equal to: setup time + measurement movement time. Location + Measurement Time polarization Location. Using the above parameter values, the total time is 60s + 0.2s. 2 360 + 1.1s 360 = 600s (i.e., 10 minutes).

[0040] Therefore, the movement time is several times longer than the measurement time. Even after deducting the setup and measurement times, 396 seconds will still be spent on the movement of the device under test alone. This means that no matter how fast the setup and measurement are, at least 396 seconds will still be needed for all the beams under test.

[0041] Finally, the AAS and the radio equipment were previously tested separately. The radio equipment was tested according to the implementation methods described in 3GPP TS25.141, 3GPP TS 36.141, 3GPP TS 37.141, and 3GPP TS 37.145-1, while the AAS was tested using a passive method that verifies the static beamform. The drawback of this method is that the entire system is not tested together, and the end-to-end system is not verified. This is particularly disadvantageous for testing AAS where the beamform varies depending on the orientation of the user equipment relative to the access network nodes; this can be completely missed in the implemented measurements and cannot be accomplished using passive testing methods.

[0042] The purpose of the embodiments disclosed herein is to address these problems by implementing measurements of multiple beams.

[0043] The embodiments disclosed herein particularly relate to a mechanism for OTA testing of AAS for EUT. To obtain such a mechanism, a network node, a method executed by the network node, and a computer program product including, for example, storing code in the form of a computer program, which, when run on the network node, causes the network node to execute the method.

[0044] The embodiments disclosed herein are based on the use of a time / frequency resource grid. Figure 1 A time / frequency resource grid 100 according to an example is schematically illustrated. The time / frequency resource grid 100 consists of resource blocks, one of which is shown by reference numeral 110. Each resource block spans multiple subcarriers in the frequency domain. Furthermore, each resource block consists of resource elements, one of which is shown by reference numeral 120. Generally, a resource element is the smallest defined unit consisting of one subcarrier during one symbol interval. Different types of time / frequency resource grids 100 may exist. In this respect, the time / frequency resource grid 100 can be used for the transmission or reception of test signals on an LTE air interface or an NR air interface. Figure 1 As shown, signals defined by the time / frequency resource grid 100 are transmitted in each time slot. Figure 1 An illustrative example shows that two time slots define a subframe, and ten subframes (i.e., 20 time slots) define a radio frame.

[0045] Figure 2This is a block diagram of system 200 according to embodiments disclosed herein. System 200 includes network node 1200, EUT 210, and test equipment (TE) 220. Furthermore, EUT 210 includes an AAS. In some examples, the AAS of EUT 210 is mounted to a locator system that can position the AAS in any theta-phi direction in a spherical coordinate system. In some aspects, system 200 defines a general setup for OTA testing of the AAS of EUT 210. Optionally, movement of at least one of EUT 210 and TE 220 is controlled by a test chamber controller. Different devices may be provided therein for EUT 210. In some non-limiting examples, EUT 210 is an access network node or user equipment, or part of an access network node or user equipment. In further non-limiting examples, EUT 210 is a radar device or vehicle (such as a car, ship, or aircraft), or part of a radar device or vehicle.

[0046] In the OTA environment 230, test signals are transmitted and received between EUT 210 and TE 220. In some examples, the OTA environment 230 is surrounded by a chamber. Test signals can be transmitted from EUT 210 to TE 220 to test the transmit characteristics of EUT 210, or test signals can be transmitted from TE 220 to EUT 210 to test the receive characteristics of EUT 210. As will be further disclosed below, the definition of the test signals to be transmitted or received by EUT 210 is obtained by network node 1200, and at network node 1200, beamforming weights are applied to the resource elements of time / frequency resource grid 100 for transmitting or receiving test signals on AAS using time / frequency resource grid 100. Therefore, test signals and beamforming weights can be injected into EUT 210 by network node 1200.

[0047] During a radio frame, a signal can be transmitted from EUT 210 to TE 220 in multiple beams 240. In this regard, the beams 240 generated by applying beamforming weights are used by EUT 210 to transmit or receive test signals. TE 220 can then use a spectrum analyzer (SA) to analyze the in-phase quadrature (IQ) data of the signals received by TE 220 to estimate the amplitude / phase of each beam. This process can be performed for different theta-phi directions to obtain the spatial performance of EUT 210 (or its AAS). Post-processing can then be applied to extract the beam properties defined in the time / frequency resource grid 100. By analyzing the IQ data instead of just measuring RF power, the IQ data can be demodulated, and the amplitude / phase of each individual beam can be extracted. The same principle can be applied when the test signal is sent from the TE 220 to the EUT 210, but a signal generator (SG) is used as the transmitter at the TE 220, and post-processing is performed by tracking the amplitude / phase of each beam type at the baseband in the EUT 210. Therefore, by using a suitable time / frequency resource grid, measurements can be performed simultaneously on multiple beams.

[0048] Figure 3 This is a flowchart illustrating an embodiment of a method for OTA testing of AAS for EUT 210. The method is performed by network node 1200. Advantageously, the method is provided as computer program 1420.

[0049] Generally, this method is based on configuring beamforming weights on the time / frequency resource grid 100 for the test signal, thereby adding a spatial information layer to the resource grid 100. Then, signaling defined by the time / frequency resource grid 100 is sent or received by the AAS.

[0050] S102: Network node 1200 obtains the definition of the test signal to be sent or received by EUT 210 according to the time / frequency resource grid 100. In some examples, the test signal is defined or specified by a test model. Therefore, in some aspects, the definition of the test signal is obtained by utilizing a test model that defines or specifies the test signal according to its definition.

[0051] S104: Network node 1200 applies a first beamforming weight to a first selected resource element 120 of the time / frequency resource grid 100, which gives a first beam direction according to a first type configuration for a first OTA test of AAS. In other words, the first selected resource element is chosen as the first type configuration to give the first beam direction. The term "selected" is used here to indicate that the first beamforming weight is not applied to all available resource elements, but only to a few specially selected resource elements 120 of the time / frequency resource grid 100.

[0052] S108: Network node 1200 applies a second beamforming weight to a second selected resource element 120 of the time / frequency resource grid 100, which gives a second beam direction according to a second type configuration for a second OTA test for AAS. The term "selected" is used here to indicate that the second beamforming weight is not applied to all available resource elements, but only to some specially selected resource elements 120 of the time / frequency resource grid 100.

[0053] S114: Network node 1200 initiates the transmission or reception of test signals on the AAS using the time / frequency resource grid 100. In this respect, the actual OTA transmission or reception of the test signals is performed by the EUT 210 or its AAS.

[0054] This method enables the measurement of a large number of beams to be executed in a short period of time.

[0055] Advantageously, this method provides OTA testing of AAS that is efficient in terms of implementation complexity and time constraints.

[0056] Advantageously, this method enables a significant reduction in test time for AAS system testing. Currently, there are some limitations on the number of beams used per measurement. These are primarily instrument-side limitations, but the proposed aspects are not limited to a maximum number of beams. Test model modes can typically be extended to more than one radio frame.

[0057] Advantageously, including multiple beams in the same test signal makes it possible to measure parameters that require phase relationships (such as orthogonality) and changes between beams (i.e., transient beam behavior).

[0058] Advantageously, this method allows AAS to be tested in a way that is more closely related to how it actually works, rather than applying custom beamforming weights to the beamform.

[0059] Advantageously, regardless of the base station type (BS 1-C, BS 1-H, BS 1-O, and BS 2-O) specified in subclause 4.6 of 3GPP TS 38.104, this method enables the testing of spatial characteristics.

[0060] Advantageously, regardless of the beamforming technique used (analog, digital, or hybrid beamforming), this method enables the testing of spatial characteristics.

[0061] Advantageously, this method enables improved overall accuracy of the test by reducing the risk of factors such as temperature drifting over time.

[0062] Advantageously, by applying different beamforming weights to individual resource elements in the resource grid regardless of sign, this method enables different beams to be placed in the time / frequency resource grid 100. These beams are then extracted from the time / frequency resource grid 100 at an instrument or base station, depending on the measurement.

[0063] In view of the above, the embodiments disclosed herein can utilize the multi-beaming properties of LTE and NR radio frame structures defined by the time / frequency resource grid 100, such as Figure 1 As shown in the example. For both digital beamforming and analog beamforming, the running network node 1200 continuously applies different beamforming weights (in complex form) to the signals transmitted and received in different beams. These beamforming weights determine the amplitude and phase of each antenna branch of the transmitted or received signal.

[0064] The concept of the LTE / NR test model defined in the 3GPP specifications (3GPP TS 37.145-2 for MSR and 3GPP TS 38.141-2 for NR) is extended by adding a spatial component (in terms of the second beamforming weight) applied to the time / frequency resource grid 100, thereby enabling efficient control of beam orientation during OTA testing of the EUT 210. Beamforming weights are applied to resource elements (symbols) in a known pattern, and the test signal will then contain multiple beams.

[0065] Applying a second beamforming weight during OTA testing does not alter statistical behavior (e.g., peak to average power ratio (PAPR)). Test signals in 3GPP (test models and Fixed Reference Channels (FRCs)) are defined by TAB ports, without considering beamforming aspects. The embodiments disclosed herein are based on the fact that beamforming weights are not defined for test models and FRCs in 3GPP, and the embodiments disclosed herein enable the addition of spatial components (with respect to the second beamforming weight) to accelerate OTA testing.

[0066] An embodiment relating to further details of the OTA test of EUT 210 AAS performed by network node 1200 will now be disclosed.

[0067] There can be different ways to send or receive test signals in step S114. In this regard, EUT 210 can be configured to operate in time division duplex (TDD) or frequency division duplex (FDD) mode, or a combination of TDD and FDD modes.

[0068] Different configuration types are possible. In some embodiments, the first type of configuration is the default configuration for AAS's default OTA testing, and the second type of configuration is a custom configuration for AAS's custom OTA testing. This allows AAS's default OTA testing to be seamlessly integrated with AAS's custom OTA testing.

[0069] The aspects related to beamforming weights will now be disclosed.

[0070] In some examples, the first beamforming weight is defined to satisfy the conformance direction specified by 3GPP. In some examples, there are exactly five such conformance directions.

[0071] There are different ways to determine the second beamforming weights. In some embodiments, the second beamforming weights are defined by an index of the beamforming codebook or determined from measurements of the received reference signal. Thus, the received reference signal is the reference signal received by the EUT 210 via OTA, where measurements are performed by the EUT 210 or network node 1200. In some examples, the second beamforming weights are defined to satisfy the beam direction generated by a codebook of beams defined in the beam configuration grid. For systems using reciprocal beamforming, a fine test beam grid can be created to characterize the system. In some examples, the second beamforming weights correspond to customer-specific beams to provide customers with more detailed information about the equipment under test required for cell planning.

[0072] In some aspects, the second beamforming weights and the second selected resource element 120 to which they are applied are stored for future use. Therefore, in some embodiments, the network node 1200 is configured to perform (optionally) step S106: S106: Network node 1200 stores the second beamforming weights and their association with the second selected resource element 120. Therefore, this association can represent a mapping describing which second beamforming weights are applied to which second selected resource elements 120.

[0073] Storing beamforming weights on top of the time / frequency resource grid 100 allows for fast data readout, which is typically matched to the sampling rate of analog-to-digital (ADC) and digital-to-analog (DAC) conversions in radio equipment. Since beamforming weights can usually be generated offline, the uploading of beamforming weights can be made slower in time.

[0074] As disclosed above, the second beamforming weight is applied to the second selected resource element 120 of the time / frequency resource grid 100. These resource elements can be selected in different ways. In some embodiments, the second beamforming weight is applied to the second selected resource element 120 representing CRS symbols, CSI-RS symbols, and PDSCH symbols, or it is applied to the second selected resource element 120 representing broadcast symbols (such as SSB or BCH symbols). As a non-limiting example, the second beamforming weight is applied to the second selected resource element 120 representing four CRS symbols, eight CSI-RS symbols, and / or ten PDSCH service symbols. Therefore, as an illustrative example, for LTE FDD, the 3GPP-defined test model E-TM1.1 (defined in subclause 4.12.2 of 3GPP TS 37.145-2 for LTE, and correspondingly in subclause 4.9.2 of 3GPP TS 38.141-2 for NR) can be extended so that four CRS symbols plus eight CSI-RS symbols are transmitted, and the PDSCH beamforming weights are set by having a unique codebook index for each subframe. This defines a test model containing 4+8+10=22 different simultaneous beams.

[0075] In some aspects, the second beamforming weights applied to PDSCH service or broadcast symbols are set to different beams between frames. Specifically, in some embodiments, test signals are transmitted or received within a frame, and the second beamforming weights applied to the second selected resource element 120 representing the PDSCH symbol differ between frames. Thus, as an illustrative example, for NR TDD frequency range 2 (FR2), the 3GPP-defined test model NR-FR2-TM1.1 (sub-clause 4.9.2 of 3GPP TS 38.141-2) is extended in such a way that the PDSCH beamforming weights for each time slot are set to different beams in the available beam grid. This can then be stacked across multiple frames for more than 1024 different simultaneous beams.

[0076] Further regarding the second selected resource element 120, information identifying these resource elements can be passed as auxiliary information to the test device (TE) 220, which is intended to receive or transmit test signals. Therefore, in some embodiments, the network node 1200 is configured to perform (optionally) step S110: S110: Network node 1200 provides information to test equipment (TE) 220, which is intended to receive or send test signals, about a second selected resource element 120 of time / frequency resource grid 100.

[0077] In some aspects, the transmission or reception of test signals on the AAS is synchronized with the test chamber controller in the test chamber intended to transmit or receive test signals. Therefore, in some embodiments, network node 1200 is configured to perform (optionally) step S112: S112: Network node 1200 provides the test chamber controller in the test chamber, which is intended to send or receive test signals, with time synchronization information about the transmission or reception of test signals on the AAS.

[0078] The various aspects of how to send or receive test signals in step S114 will now be disclosed.

[0079] Generally, the application of the first beamforming weight and the second beamforming weight causes the test signal to be transmitted or received in beam 240. That is, in some embodiments, the test signal is transmitted or received in beam 240 according to the first beamforming weight and the second beamforming weight. Each beam may then contain information about its placement in the time / frequency resource grid 100. Therefore, in some embodiments, the test signal transmitted or received in each beam 240 contains information about which resource elements within the time / frequency resource grid 100 have been used by which beamforming weights.

[0080] Furthermore in this respect, each beam 240 may include amplitude and phase information for each antenna port. In particular, in some embodiments where test signals are transmitted or received at antenna ports of the AAS and first beamforming weights and second beamforming weights are defined in terms of amplitude and phase information, the test signals transmitted or received in each beam 240 include amplitude and phase information for each antenna port.

[0081] Now refer to Figures 4 to 8The block diagrams disclose different interface implementations regarding how network node 1200 obtains test signals sent or received by EUT 210, how network node 1200 applies first beamforming weights, how network node 1200 applies second beamforming weights, and how network node 1200 initiates the transmission or reception of test signals on AAS using time / frequency resource grid 100. Each of these block diagrams illustrates a corresponding implementation of network node 1200 and EUT 210.

[0082] exist Figure 4 In its implementation, beamforming weight data frame 1241 contains information about the beamforming weights of one or more beams. Each beam has corresponding amplitude and phase information for each antenna port. Each beam also has corresponding information about its placement in the resource grid. Test model data frame 1242 contains information about the signal to be transmitted by EUT 210. In the resource grid information generation process frame 1243, a time / frequency resource grid 100 to be used is generated. A first beamforming weight is applied to a first selected resource element 120 of the time / frequency resource grid 100, as in S104, and a second beamforming weight is applied to a second selected resource element 120 of the time / frequency resource grid 100, as in S108. A new resource grid data frame 1244 contains the generated time / frequency resource grid 100. In the grid application process frame 1245 on the EUT, network node 1200 initiates the transmission or reception of test signals using the time / frequency resource grid 100. In the transmit / receive resource grid process block 211, test signals are transmitted or received on the AAS using the time / frequency resource grid 100.

[0083] exist Figure 5In the implementation, the predefined index data frame 1241' contains information about one or more beams in terms of predefined indices in the beamforming codebook. Each beam has corresponding amplitude and phase information for each antenna port. Each beam has corresponding information about its placement within the resource grid. The test model data frame 1242 contains information about the signal to be transmitted by the EUT 210. In the resource grid information generation process frame 1243, the time / frequency resource grid 100 to be used is generated. A first beamforming weight is applied to a first selected resource element 120 of the time / frequency resource grid 100, as in S104, and a second beamforming weight defined by the predefined indices from the beamforming codebook of data frame 1241' is applied to a second selected resource element 120 of the time / frequency resource grid 100, as in S108. The new resource grid data frame 1244 contains the generated time / frequency resource grid 100. In the EUT application grid procedure block 1245, network node 1200 initiates the transmission or reception of test signals using time / frequency resource grid 100. In the transmit / receive resource grid procedure block 211, test signals are transmitted or received on AAS using time / frequency resource grid 100.

[0084] exist Figure 6 In its implementation, beamforming weight data frame 1241 contains information about the beamforming weights of one or more beams. Each beam has corresponding amplitude and phase information for each antenna port. Each beam has corresponding information about its placement within the resource grid. Test model data frame 1242 contains information about the signal to be transmitted by EUT 210. In the resource grid information generation process frame 1243', a time / frequency resource grid 100 to be used is generated. A first beamforming weight is applied to a first selected resource element 120 of the time / frequency resource grid 100, as in S104. Resource grid data frame 1244' contains the generated time / frequency resource grid 100. In the grid application process frame 1245 on the EUT, network node 1200 initiates the transmission or reception of a test signal using the time / frequency resource grid 100. In the weight application process frame 1246 on the EUT, a second beamforming weight is applied to a second selected resource element 120 of the time / frequency resource grid 100, as in S108. In the process block 212 of combining the grid and weights, the time / frequency resource grid 100 defined by process block 1245 is combined with the time / frequency resource grid 100 defined by process block 1246. In the transmit / receive resource grid process 211, test signals are transmitted or received on the AAS using the time / frequency resource grid 100.

[0085] exist Figure 7In the implementation, the predefined index data frame 1241' contains information about the predefined indexes of one or more beams in the beamforming codebook. Each beam has corresponding amplitude and phase information for each antenna port. Each beam has corresponding information about its placement within the resource grid. The test model data frame 1242 contains information about the signals to be transmitted by the EUT 210. In the resource grid information generation process frame 1243', the time / frequency resource grid 100 to be used is generated. A first beamforming weight is applied to the first selected resource element 120 of the time / frequency resource grid 100, as in S104. The resource grid data frame 1244' contains the generated time / frequency resource grid 100. In the grid application process frame 1245 on the EUT, the network node 1200 initiates the transmission or reception of test signals using the time / frequency resource grid 100. In the EUT application process block 1246', a second beamforming weight, defined by a predefined index from the beamforming codebook of data block 1241', is applied to the second selected resource element 120 of the time / frequency resource grid 100, as in S108. In the grid-weight combination block 212, the time / frequency resource grid 100 defined by process block 1245 is combined with the time / frequency resource grid 100 defined by process block 1246. In the transmit / receive resource grid process block 211, test signals are transmitted or received on the AAS using the time / frequency resource grid 100.

[0086] exist Figure 8In its implementation, beamforming weight data frame 1241 contains information about the beamforming weights of one or more beams, and predefined index data frame 1241' contains information about the predefined indices of one or more beams in the beamforming codebook. Each beam has corresponding amplitude and phase information for each antenna port. Each beam has corresponding information about its placement within the resource grid. Test model data frame 1242 contains information about the signal to be transmitted by EUT 210. In the resource grid information generation process frame 1243, a time / frequency resource grid 100 to be used is generated. A first beamforming weight is applied to a first selected resource element 120 of the time / frequency resource grid 100, as in S104, and a second beamforming weight defined by the predefined indices from the beamforming codebook of data frame 1241' is applied to a second selected resource element 120 of the time / frequency resource grid 100, as in S108. A new resource grid data frame 1244 contains the generated time / frequency resource grid 100. In the mesh application procedure block 1245 on the EUT, network node 1200 initiates the transmission or reception of test signals using the time / frequency resource grid 100. In the weight loading and index allocation procedure block 1247, second beamforming weights are stored in the middle. Further, if the beam is not predefined but must be loaded into the EUT 210, the second beamforming weights can be loaded into the EUT 210 from block 1247. The index data block 213 of the weight table contains a beam index lookup table pointing to the beamforming weights. The index data block 213 of the weight table can provide a method for overriding existing beams or creating new beams, such as when a beam is not predefined but must be loaded into the EUT 210. In the transmit / receive resource grid procedure block 211, test signals are transmitted or received on the AAS using the time / frequency resource grid 100.

[0087] Now refer to Figure 9 The flowchart discloses a specific embodiment of OTA testing for AAS of EUT 210 performed by network node 1200.

[0088] Test model data frame 910 contains information about the signals to be sent by EUT 210. A resource grid, including multiple resource blocks and symbols for testing, is defined here.

[0089] The beamforming weight data frame 920 contains information about one or more beams. Each beam has corresponding amplitude and phase information for each antenna port. Each beam also has corresponding information about its placement within the resource grid.

[0090] In the process block 930 of applying the test model and beamforming weights to resource elements, data from the test model and beamforming weights are combined into a resource grid containing symbol and beamforming weight information for each resource element in the resource grid. The signal defined by this resource grid is then transmitted by the device under test.

[0091] In measurement procedure block 940, depending on the DL / UL configuration, data is collected by demodulating the received signals by the test equipment or the device under test. The data includes a resource grid. The actions performed in this procedure block can be repeated for any number of angular positions.

[0092] In the data sorting process block 950, to obtain information for each individual beam, the resource elements containing beam data for each beam are sorted. This can be one or more resource elements if averaging is required. If a power value representing the entire carrier is required, these beams can be scaled using the following calculation:

[0093] Wherein, carrier power represents carrier power. This represents the power of each resource element. Indicates the number of resource blocks, and This represents the number of subcarriers per resource block. As an illustrative numerical example, for... , and A 10MHz LTE carrier generates:

[0094] In the process block 960 for extracting individual beam shapes, the beam shapes are extracted using resource elements that contain the beams and the angles at which they are measured.

[0095] Figure 10 The following is illustrated in block diagram 1000, showing how the example is executed. K OTA tests with different configurations. Configuration box 1030 contains settings for one or more EUT 210s. K A second beamforming weight, which may also test the signal and / or the first beamforming weight. Based on constraint 1010, it is generated in generation box 1020. K One configuration. Test box 1040 is shown schematically. K OTA testing of several different configurations (one or more configurations per EUT 210). Process data frame 1050 schematically illustrates the process from... K Test data, such as IQ values, generated from OTA tests with different configurations. At least 1020 boxes can be generated in a cloud computing environment.

[0096] Figure 11 The block diagram 1000 illustrates how, according to the example, the process for one or more EUT 210s can be performed. M Analysis of different antenna patterns. IQ DataFrame 1110 provides information from (such as...) Figure 10 The process data frame 1050 obtains test data on IQ values ​​generated by one or more different configurations of OTA testing. The distribution frame 1120 distributes the IQ values ​​to... L Demodulation process block 1130. L Each demodulation block 1130 demodulates the received IQ value. Assembly block 1140 assembles all demodulated IQ values ​​into an IQ value sequence. Sorting block 1150 sorts the assembled IQ value sequences for each antenna pattern to obtain... M A sorted sequence of assembled IQ values. Antenna diagram 1160 generates an antenna diagram for each sorted sequence of assembled IQ values, thereby producing... M Antenna diagram. Boxes 1120:1160 can be implemented in a cloud computing environment.

[0097] Figure 12 The components of the network node 1200 according to an embodiment are schematically shown in the form of multiple functional units. The processing circuitry 1210 is provided using any combination of one or more of the following: a suitable central processing unit (CPU), multiprocessor, microcontroller, digital signal processor (DSP), etc., capable of executing a computer program product 1410 (such as...). Figure 14 The software instructions (shown) are provided, for example, in the form of storage medium 1230. The processing circuitry 1210 may further be provided as at least one application-specific integrated circuit (ASIC) or field-programmable gate array (FPGA).

[0098] Specifically, the processing circuit 1210 is configured to cause the network node 1200 to perform the set of operations or steps described above. For example, the storage medium 1230 may store the operation set, and the processing circuit 1210 may be configured to retrieve the operation set from the storage medium 1230 to cause the network node 1200 to execute the operation set. The operation set may be provided as a set of executable instructions.

[0099] Therefore, processing circuitry 1210 is arranged to perform the methods disclosed herein. Storage medium 1230 may also include persistent memory, which may be any single or combination thereof, such as magnetic storage, optical storage, solid-state storage, or even remotely mounted memory. Network node 1200 may also include communication interface 1220, which is configured at least to communicate with other entities, functions, nodes, and devices (such as at least EUT 210). Therefore, communication interface 1220 may include one or more transmitters and receivers, comprising analog and digital components. Processing circuitry 1210 controls the general operation of network node 1200, for example, by sending data and control signals to communication interface 1220 and storage medium 1230, by receiving data and reports from communication interface 1220, and by retrieving data and instructions from storage medium 1230. Other components and related functions of network node 1200 are omitted to avoid obscuring the concepts presented herein.

[0100] Figure 13 The components of the network node 1200 according to an embodiment are schematically shown in the form of multiple functional modules. Figure 13 The network node 1200 includes multiple functional modules: an acquisition module 1210a configured to execute step S102, a first application module 1210b configured to execute step S104, a second application module 1210d configured to execute step S108, and an initiation module 1210g configured to execute step S114. Figure 13 The network node 1200 may further include a plurality of optional functional modules, such as any one of the storage module 1210c configured to perform step S106, the first providing module 1210e configured to perform step S110, and the second providing module 1210f configured to perform step S112. Generally, each functional module 1210a:1210g may be implemented solely in hardware in one embodiment, while in another embodiment it may be implemented in software, i.e., the latter embodiment has computer program instructions stored on the storage medium 1230 that, when executed on the processing circuitry, cause the network node 1200 to perform the aforementioned combination. Figure 13 The corresponding steps described herein. It should also be mentioned that even though modules correspond to parts of a computer program, they need not be separate modules within it; however, the way they are implemented in the software depends on the programming language used. Preferably, one or more of the functional modules 1210a:1210g may be implemented by the processing circuitry 1210, which may cooperate with the communication interface 1220 and / or the storage medium 1230. Therefore, the processing circuitry 1210 may be configured to retrieve instructions provided by the functional modules 1210a:1210g from the storage medium 1230 and execute these instructions to perform any of the steps disclosed herein.

[0101] Network node 1200 can be provided as a standalone device or as part of at least one other device. For example, network node 1200 can be provided in a node of a (radio) access network or in a node of a core network. Alternatively, the functionality of network node 1200 can be distributed among at least two devices or nodes. These at least two nodes or devices can be part of the same network segment (such as a (radio) access network or a core network), or can be distributed among at least two such network segments. Generally, instructions that require real-time execution can be executed in devices or nodes that are operationally closer to the cell, compared to instructions that do not require real-time execution.

[0102] Therefore, the first portion of the instructions executed by network node 1200 can be executed in a first device, and the second portion of the instructions executed by network node 1200 can be executed in a second device; the embodiments disclosed herein are not limited to any particular number of devices on which the instructions executed by network node 1200 can be executed. Therefore, the method according to the embodiments disclosed herein is suitable for execution by network node 1200 residing in a cloud computing environment. Therefore, although a single processing circuit 1210 in Figure 12 As shown, the processing circuitry 1210 can be distributed across multiple devices or nodes. This also applies to… Figure 13 Functional modules 1210a, 1210g, and Figure 14 Computer program 1420.

[0103] Figure 14 An example of a computer program product 1410 including a computer-readable storage medium 1430 is shown. On this computer-readable storage medium 1430, a computer program 1420 may be stored, which can cause processing circuitry 1210 and its operatively coupled entities and devices (such as a communication interface 1220 and storage medium 1230) to perform methods according to the embodiments described herein. Therefore, computer program 1420 and / or computer program product 1410 can provide methods for performing any of the steps disclosed herein.

[0104] exist Figure 14In the example, computer program product 1410 is illustrated as an optical disc, such as a CD (Optical Disc), DVD (Digital Multifunction Optical Disc), or Blu-ray Disc. Computer program product 1410 can also be embodied as memory, such as random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM), or electrically erasable programmable read-only memory (EEPROM), and more specifically, as a non-volatile storage medium for a device in external memory, such as USB (Universal Serial Bus) memory or flash memory, such as compact flash memory. Therefore, when computer program 1420 is schematically shown herein as tracks on the depicted optical disc, computer program 1420 can be stored in any manner suitable for computer program product 1410.

[0105] Figure 15 This is a schematic diagram illustrating a telecommunications network connected to a host computer 430 via an intermediate network 420 according to some embodiments. According to an embodiment, the communication system includes a telecommunications network 410, such as a 3GPP-type cellular network, which includes an access network 411 and a core network 414. The access network 411 includes multiple (radio) access network nodes 412a, 412b, 412c, such as NB, eNB, gNB, or other types of wireless access points, each defining a corresponding coverage area or cell 413a, 413b, 413c. Each (radio) access network node 412a, 412b, 412c can be connected to the core network 414 via a wired or wireless connection 415. A first UE 491 located in coverage area 413c is configured to wirelessly connect to or be paged by the corresponding (radio) access network node 412c. A second UE 492 located in coverage area 413a can wirelessly connect to the corresponding network node 412a. Although multiple UEs 491, 492 are illustrated in this example, the disclosed embodiments are equally applicable to situations where a single UE is located within the coverage area or a single terminal device is connected to the corresponding network node 412. EUT 210 may be part of one or more access network nodes 412a, 412b, 412c or one or more UEs 491, 492.

[0106] Telecommunications network 410 is itself connected to host computer 430, which may be embodied in the hardware and / or software of a standalone server, a cloud-implemented server, a distributed server, or as a processing resource in a server cluster. Host computer 430 may be under the ownership or control of a service provider, or may be operated by the service provider or on behalf of the service provider. Connections 421 and 422 between telecommunications network 410 and host computer 430 may extend directly from core network 414 to host computer 430, or may be via optional intermediate network 420. Intermediate network 420 may be one or more of public, private, or hosted networks; intermediate network 420, if present, may be a backbone network or the Internet; in particular, intermediate network 420 may include two or more subnetworks (not shown).

[0107] Figure 15 The communication system shown overall realizes the connection between the connected UEs 491, 492 and the host computer 430. This connection can be described as an over-the-top (OTT) connection 450. The host computer 430 and the connected UEs 491, 492 are configured to transmit data and / or signaling via the OTT connection 450 using access network 411, core network 414, any intermediate network 420 and possible further infrastructure (not shown) as intermediaries. The OTT connection 450 can be transparent in the sense that the participating communication devices traversing the OTT connection 450 are unaware of the routes of uplink and downlink communications. For example, network node 412 may not be informed, or need not be informed, of past routes of incoming downlink communications originating from host computer 430 that will be forwarded (e.g., transferred) to the connected UE 491. Similarly, network node 412 does not need to know the future routes of outgoing uplink communications originating from UE 491 toward host computer 430.

[0108] Figure 16 This is a schematic diagram illustrating a host computer communicating with a UE via a (radio) access network node through a partially wireless connection, according to some embodiments. Reference will now be made to... Figure 16This section describes an example implementation of the UE, (radio) access network node, and host computer discussed in the preceding paragraphs, according to an embodiment. In the communication system 500, the host computer 510 includes hardware 515, which includes a communication interface 516 configured to establish and maintain a wired or wireless connection to different communication devices of the communication system 500. The host computer 510 also includes processing circuitry 518, which may have storage and / or processing capabilities. Specifically, the processing circuitry 518 may include one or more programmable processors, application-specific integrated circuits, field-programmable gate arrays, or combinations thereof (not shown), adapted to execute instructions. The host computer 510 also includes software 511, which is stored in or accessible by the host 510 and executable by the processing circuitry 518. The software 511 includes a host application 512. The host application 512 is operable to provide services to remote users, such as UE 530 connected via an OTT connection 550 terminated at UE 530 and host computer 510. When providing services to remote users, host application 512 can provide user data sent using OTT connection 550.

[0109] The communication system 500 also includes a (radio) access network node 520, which is provided in the telecommunications system and includes hardware 525 enabling it to communicate with the host computer 510 and the UE 530. Hardware 525 may include a communication interface 526 for establishing and maintaining wired or wireless connections with different communication devices of the communication system 500, and for establishing and maintaining connections with areas located within the coverage area served by the (radio) access network node 520 (not in...). Figure 16 The UE 530 (shown in the diagram) has at least a radio interface 527 for a wireless connection 570. A communication interface 526 can be configured to facilitate a connection 560 to the host 510. The connection 560 can be direct, or it can traverse the core network of the telecommunications system (not shown in the diagram). Figure 16 (As shown in the diagram) and / or traverse one or more intermediate networks outside the telecommunications system. In the illustrated embodiment, the hardware 525 of the (radio) access point network node 520 also includes processing circuitry 528, which may include one or more programmable processors, application-specific integrated circuits, field-programmable gate arrays, or combinations thereof (not shown), adapted to execute instructions. The access network node 520 also has software 521 stored internally or accessible via an external connection.

[0110] The communication system 500 further includes the already mentioned UE 530. Its hardware 535 may include a radio interface 537 configured to establish and maintain a wireless connection 570 with a (radio) access network node serving the coverage area currently occupied by the UE 530. The hardware 535 of the UE 530 also includes processing circuitry 538, which may include one or more programmable processors, application-specific integrated circuits, field-programmable gate arrays, or combinations thereof (not shown), adapted to execute instructions. The UE 530 also includes software 531, which is stored in or accessible by the UE 530 and executable by the processing circuitry 538. The software 531 includes a client application 532. The client application 532 may be operable to provide services to human or non-human users via the UE 530 with the support of a host computer 510. In the host computer 510, a host application 512 executing may communicate with the executing client application 532 via an OTT connection 550 terminated at both the UE 530 and the host computer 510. When providing services to a user, client application 532 can receive request data from host application 512 and provide user data as a response to the request data. OTT connection 550 can transmit both request data and user data. Client application 532 can interact with the user to generate the user data it provides.

[0111] It should be noted that Figure 16 The host computer 510, (radio) access network node 520, and UE 530 shown can respectively connect to... Figure 15 The host computer 430, one of the (radio) access network nodes 412a, 412b, and 412c, and one of the UEs 491 and 492 are similar to or the same. That is, the internal workings of these entities can be as follows: Figure 16 As shown, and independently, the surrounding network topology can be Figure 15 The network topology. Therefore, EUT 210 can be part of access network node 520 or EUT 530.

[0112] exist Figure 16 The OTT connection 550 has been abstractly depicted to illustrate communication between host computer 510 and UE 530 via network node 520, without explicitly mentioning any intermediate devices or the precise routing of messages through these devices. The network infrastructure can determine the routing, which can be configured to hide the routing to UE 530, the service provider operating host computer 510, or both. When OTT connection 550 is active, the network infrastructure can further make dynamic decisions to change the routing (e.g., based on load balancing considerations or network reconfiguration).

[0113] The wireless connection 570 between UE 530 and (radio) access network node 520 conforms to the teachings of the embodiments described throughout this disclosure. One or more embodiments in the various embodiments improve the performance of the OTT service provided to UE 530 by the OTT connection 550, which constitutes the final segment of the wireless connection 570. More specifically, the teachings of these embodiments can reduce interference because the classification capability of the over-the-air UE is improved, which can cause significant interference.

[0114] Measurement procedures may be provided for monitoring data rates, latency, and other factors improved by one or more embodiments. Optional network functions may also exist for reconfiguring the OTT connection 550 between host computer 510 and UE 530 in response to changes in measurement results. The measurement procedures and / or the network functions for reconfiguring the OTT connection 550 may be implemented in software 511 and hardware 515 of host computer 510, or in software 531 and hardware 535 of UE 530, or both. In embodiments, sensors (not shown) may be deployed in or associated with communication devices through which the OTT connection 550 passes; sensors may participate in the measurement procedures by providing values ​​of the monitored quantities exemplified above or by providing values ​​of other physical quantities from which software 511, 531 can calculate or estimate the monitored quantities. Reconfiguration of the OTT connection 550 may include message formats, retransmission settings, preferred routes, etc.; reconfiguration does not need to affect network node 520 and may be unknown or imperceptible to (radio) access network node 520. Such procedures and functions may be known and practiced in the art. In some embodiments, the measurement may involve proprietary UE signaling to facilitate the host computer 510 in measuring throughput, propagation time, latency, etc. The measurement can be implemented because software 511 and 531 causes messages (especially empty or "fake" messages) to be sent using OTT connection 550, while it monitors propagation time, errors, etc.

[0115] The concept of the present invention has been described above primarily with reference to several embodiments. However, as will be readily understood by those skilled in the art, other embodiments besides those disclosed above are also within the scope of the inventive concept as defined by the appended claims.

Claims

1. A method for over-the-air (OTA) testing of an active antenna system (AAS) for a device under test (EUT), the method being performed by a network node, the method comprising: Obtain the definition of the test signal to be sent or received by the EUT according to the time / frequency resource grid; According to a first type configuration for a first OTA test of the AAS, a first beamforming weight is applied to a first selected resource element of the time / frequency resource grid that gives a first beam direction; According to the second type configuration for the second OTA test of the AAS, the second beamforming weight is applied to the second selected resource element of the time / frequency resource grid that gives the second beam direction; as well as Initiate the transmission or reception of the test signal on the AAS using the time / frequency resource grid.

2. The method according to claim 1, wherein, The first type of configuration is the default configuration for the default OTA test of the AAS, and the second type of configuration is the custom configuration for the custom OTA test of the AAS.

3. The method according to claim 1, wherein, The test signal is transmitted or received in a beam according to the first beamforming weight and the second beamforming weight, wherein the test signal transmitted or received in each beam contains information about which beamforming weights have used resource elements within the time / frequency resource grid.

4. The method according to claim 3, wherein, The test signal is transmitted or received at the antenna port of the AAS, wherein the first beamforming weight and the second beamforming weight are defined in terms of amplitude and phase information, and wherein the test signal transmitted or received in each beam contains the amplitude and phase information for each antenna port.

5. The method according to any one of claims 1 to 3, wherein, The second beamforming weight is defined by the index of the beamforming codebook or determined based on measurements of the received reference signal.

6. The method according to any one of claims 1 to 3, wherein, The second beamforming weight is applied to the second selected resource element representing a cell-specific reference signal (CRS) symbol, a channel state information reference signal (CSI-RS) symbol, a physical downlink shared channel (PDSCH) symbol, or a synchronization signal block (SSB), or is applied to the second selected resource element representing a broadcast symbol.

7. The method according to any one of claims 1 to 3, wherein, The test signal is transmitted or received in a frame, and the second beamforming weight applied to the second selected resource element representing the PDSCH symbol is different between frames.

8. The method according to any one of claims 1 to 3, wherein, The method further includes: Information identifying the second selected resource element of the time / frequency resource grid is provided to the test equipment TE, which is designed to receive or transmit the test signal.

9. The method according to any one of claims 1 to 3, wherein, The EUT is configured for time-division duplex (TDD) operation, frequency-division duplex (FDD) operation, or a combination of TDD and FDD operations.

10. The method according to any one of claims 1 to 3, wherein, The time / frequency resource grid is used for transmitting or receiving the test signals on the Long Term Evolution (LTE) air interface, the New Radio (NR) air interface, or the Universal Mobile Telecommunications Service (UMTS) air interface.

11. The method according to any one of claims 1 to 3, wherein, The EUT is an access network node or user equipment, or a part of an access network node or user equipment.

12. The method according to any one of claims 1 to 3, wherein, The method further includes: Store the second beamforming weights and their association with the second selected resource element.

13. The method according to any one of claims 1 to 3, wherein, The method further includes: The test chamber controller in the test chamber, which is intended to send or receive the test signal, is provided with time synchronization information regarding the transmission or reception of the test signal on the AAS.

14. A network node for over-the-air (OTA) testing of an active antenna system (AAS) of a device under test (EUT), the network node including processing circuitry configured to cause the network node to: Obtain the definition of the test signal to be sent or received by the EUT according to the time / frequency resource grid; According to a first type configuration for a first OTA test of the AAS, a first beamforming weight is applied to a first selected resource element of the time / frequency resource grid that gives a first beam direction; According to the second type configuration for the second OTA test of the AAS, the second beamforming weight is applied to the second selected resource element of the time / frequency resource grid that gives the second beam direction; as well as Initiate the transmission or reception of the test signal on the AAS using the time / frequency resource grid.

15. The network node of claim 14 is further configured to perform the method of any one of claims 2 to 13.

16. A computer program product for over-the-air (OTA) testing of an active antenna system (AAS) for a device under test (EUT), comprising a computer program containing computer code that, when executed on the processing circuitry of a network node, causes the network node to: Obtain the definition of the test signal to be sent or received by the EUT according to the time / frequency resource grid; According to a first type configuration for a first OTA test of the AAS, a first beamforming weight is applied to a first selected resource element of the time / frequency resource grid that gives a first beam direction; According to the second type configuration for the second OTA test of the AAS, the second beamforming weight is applied to the second selected resource element of the time / frequency resource grid that gives the second beam direction; as well as Initiate the transmission or reception of the test signal on the AAS using the time / frequency resource grid.

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