System and method for testing device under test

Abstract

The invention relates to a system and method for testing a device under test. The system (10) for testing a device under test (DUT) (20) comprises: an output port (11) arranged to be connected to the DUT (20); a waveform generator (13) configured to generate an RF output signal and to forward the RF output signal to the DUT (20) through the output port (11); a communication interface (12) configured to receive a feedback signal from the DUT (20); and a processing unit (14) configured to dynamically generate waveform information based on the received feedback signal, where the processing unit (14) is configured to generate the waveform information from stored and / or real-time calculated waveform samples; wherein the waveform generator (13) is configured to adjust the RF output signal based on the waveform information.

Description

Technical Field

[0001] The present invention relates to a system for testing a device-under-test (DUT), in particular to a radio frequency (RF) signal generator, and a method for testing a device-under-test (DUT). Background Art

[0002] An RF signal generator can be used to provide precisely specified RF test signals to the DUT. For example, if the DUT is a communications device such as a base station, the RF test signal represents a communications signal according to a communications standard. During such testing, the test signal can be manually adjusted by operating the signal generator based on the DUT's response. However, this method is tedious and time-consuming.

[0003] Furthermore, when developing new mobile communication standards, machine learning (ML) models will be used to identify optimized signal parameters (for example, using ML models under predefined channel conditions to develop new modulation types for the standard that are more suitable for the channel). These ML models, and the resulting signals, should be adjusted in real time based on the existing channel conditions. Therefore, in order to train and validate such ML models, a feedback mechanism is required that allows the "real" RF signal characteristics (not just the characteristics of the fading channel) to be adjusted based on the adjusted model. Summary of the Invention

[0004] It is therefore an object to provide an improved system and an improved method for testing a DUT that avoid the above-mentioned disadvantages.

[0005] This object is achieved by the solution provided in this application. Advantageous implementations of the invention are further defined in this application.

[0006] According to a first aspect, the present invention relates to a system for testing a device under test (DUT). The system comprises: an output port arranged to be connected to the DUT; a waveform generator configured to generate a radio frequency (RF) output signal and forward the RF output signal to the DUT via the output port; a communication interface configured to receive a feedback signal from the DUT; and a processing unit configured to dynamically generate waveform information based on the received feedback signal, wherein the processing unit is configured to generate the waveform information based on stored and / or real-time calculated waveform samples; and wherein the waveform generator is configured to adjust the RF output signal based on the waveform information.

[0007] This achieves the advantage of providing a feedback mechanism for dynamically adjusting the RF test signal.For example, the system can be used in test scenarios where switching between various predefined signals (signal permutation) is required in real time.

[0008] Another advantage of the feedback mechanism provided by the system is that it is not application-specific (i.e., it is universal). For example, RF output signals according to various types of standards can be generated and / or adjusted (e.g., by selecting from different types of stored waveform segments), and different types of DUTs can be connected. The system is highly adjustable and can use a variety of stored waveform data (e.g., in ".wvs" format or other data formats) that can be provided by the user based on specific test scenarios.

[0009] The DUT test may be a hardware-in-the-loop (HIL) test. The DUT may be a communication device capable of providing a feedback signal, such as a base station.

[0010] A feedback signal may be received from the DUT while the RF output signal is forwarded to the DUT.

[0011] The stored waveform samples may be pre-calculated or pre-configured waveform samples that are stored in a memory of the system.

[0012] Each waveform sample can be subdivided into multiple portions having different durations (i.e., lengths of time). For example, a portion of a waveform sample suitable for generating an RF output signal according to the 5G standard may have a length of 125 μs, while a portion of a waveform sample suitable for generating an RF output signal according to the LTE standard may have a length of 500 μs.

[0013] The waveform samples may include IQ data. The waveform information may include an IQ data stream generated based on the IQ data.

[0014] The processing unit may include or be formed by a digital signal processor (DSP).

[0015] A processing unit that dynamically generates waveform information based on feedback may refer to a processing unit that generates (or updates) waveform information directly in response to a feedback signal. For example, a waveform generator may output an RF output signal based on waveform information (e.g., an IQ data stream) from the processing unit, an interface may receive feedback regarding the RF output signal, and a processor may directly adjust / change the waveform information (e.g., adjust the IQ data stream) based on the feedback, causing the waveform generator to adjust the RF output signal accordingly.

[0016] The waveform generator may include a waveform player for "replaying" waveform samples and generating an RF output signal based on these samples.

[0017] In one embodiment, the processing unit comprises a feedback interpreter configured to generate and / or update a feedback configuration based on the feedback signal, wherein the feedback configuration comprises a plurality of consecutive segments, wherein each segment references or contains a portion of a corresponding stored or calculated waveform sample having a determined duration.

[0018] Thus, a feedback configuration can represent a sequence or string of waveform segments, each waveform segment having a specific duration. An RF output signal can be continuously generated or adjusted based on the sequence. For example, while an RF output signal is being generated based on one waveform segment, the next segment in the feedback configuration can be generated / adjusted based on the feedback signal.

[0019] In one embodiment, the processing unit includes a feedback configurator configured to map the feedback signal to a corresponding portion of a stored or calculated waveform sample based on a mapping rule for each segment, and forward the mapping to a feedback interpreter; wherein the feedback interpreter is configured to generate the feedback configuration based on the mapping.

[0020] The processing unit, or more specifically the feedback configurator, may comprise a pre-selector configured to determine, based on the feedback message, which waveform segments should be selected or calculated.

[0021] In one embodiment, the feedback configurator is configured to calculate at least one waveform sample in real time based on the feedback message.

[0022] In one embodiment, the processing unit includes a sample provider configured to continuously receive the feedback configuration and dynamically generate waveform information based on portions of stored or calculated waveform samples referenced in or included by consecutive segments in the feedback configuration.

[0023] For example, the sample provider is an IQ sample provider (or IQ sample creator) configured to combine the IQ data of the waveform segments into an IQ data string, which can be fed to the waveform generator to generate / adjust the RF output signal.

[0024] In one embodiment, the system includes a memory configured to store the stored waveform samples.

[0025] The stored waveform samples may include waveform samples provided by a user or a third party, and / or pre-calculated or pre-configured waveform samples.

[0026] In one embodiment, the memory is a shared memory in the communication network. This provides the advantage that waveform data from different users or other entities can be stored in shared hardware.

[0027] In one embodiment, the system further comprises an access unit configured to access the memory and forward the stored portions of the waveform sample from the memory to the sample provider. The access unit may forward the stored portions of the waveform sample according to the feedback configuration.

[0028] In one embodiment, the access unit is further configured to receive further waveform samples of different duration and / or with different characteristics and to store the further waveform samples in the memory.

[0029] In one embodiment, the communication interface is a wireless or wired binding interface.

[0030] For example, the communication interface may be a Bluetooth interface or a USB interface.

[0031] The feedback signal can be a proprietary message or a DCI (5G standard) message.

[0032] In one embodiment, the communication interface is a serial interface configured to receive the feedback signal at a serial data rate.

[0033] In one embodiment, the waveform generator includes an IQ sample streamer and / or a digital-to-analog converter (DAC).

[0034] The waveform samples and / or waveform information may be digital data.The generated RF output signal may be an analog output signal.

[0035] The waveform generator (or player) can be configured to replay a predetermined waveform or a portion of a predetermined waveform to generate a desired RF output signal. The IQ sample streamer can be configured to obtain IQ samples from a source (e.g., a sample provider) and forward them to the DAC converter. For example, the IQ sample streamer writes the IQ samples to hardware shared with the DAC converter. The DAC converter can be a DAC IQ player.

[0036] In one embodiment, the waveform generator and the processing unit are integrated into a common device, or the waveform generator is a standalone device.

[0037] In one embodiment, the waveform generator is configured to receive waveform information in the form of an IQ data stream, wherein the waveform generator is configured to dynamically adjust the RF output signal based on the IQ data stream.

[0038] In one embodiment, the system is an RF signal generator.

[0039] According to a second aspect, the present invention relates to a method for testing a device under test (DUT). The method comprises: generating an RF output signal and forwarding the RF output signal to the DUT; receiving a feedback signal from the DUT; dynamically generating waveform information based on the received feedback signal, wherein the waveform information is generated based on stored and / or real-time calculated waveform samples; and adjusting the RF output signal based on the waveform information. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The above aspects and implementations are explained in the following description of embodiments with reference to the accompanying drawings:

[0041] Figure 1 shows a schematic diagram of a system for testing a DUT according to one embodiment;

[0042] Figure 2 shows generating an RF output signal from stored waveform samples according to one embodiment;

[0043] Figure 3 shows a mapping rule according to one embodiment;

[0044] Figure 4 A schematic diagram illustrating a system for testing a DUT according to one embodiment is shown; and

[0045] Figure 5 A flow chart of a method for testing a DUT according to one embodiment is shown. DETAILED DESCRIPTION

[0046] Figure 1 A schematic diagram of a system 10 for testing a DUT 20 is shown according to one embodiment.

[0047] The system 10 includes an output port 11 arranged to be connected to a DUT 20, a waveform generator 13 configured to generate an RF output signal and forward the RF output signal to the DUT 20 via the output port 11, and a communication interface 12 configured to receive a feedback signal from the DUT 20. The system 10 may further include a processing unit 14 configured to dynamically generate waveform information based on the received feedback signal, wherein the processing unit 14 is configured to generate the waveform information based on stored and / or real-time calculated waveform samples, and wherein the waveform generator 13 is configured to adjust the RF output signal based on the waveform information.

[0048] The output port 11 may be an RF port.

[0049] The RF output signal can be configured according to the test scenario and further adjusted based on the feedback signal. For example, the RF output signal corresponds to a signal according to a communication standard (such as 5G or LTE).

[0050] The communication interface 12 may be a wireless or wired interface. For example, the communication interface 12 may be a Bluetooth interface or a USB interface.

[0051] A feedback signal may be received from the DUT 20 while the RF output signal is forwarded to the DUT 20. The feedback signal may include a proprietary message or a DCI (5G standard) message.

[0052] The stored or calculated waveform samples and / or waveform information may be digital data. The waveform samples may include IQ data. The waveform information may include an IQ data stream generated based on the IQ data.

[0053] Each waveform sample can be subdivided into multiple portions having different durations (i.e., lengths of time). For example, a portion of a waveform sample suitable for generating an RF output signal according to the 5G standard may have a length of 125 μs, while a portion of a waveform sample suitable for generating an RF output signal according to the LTE standard may have a length of 500 μs.

[0054] The generated RF output signal forwarded to the DUT 20 may be an analog output signal.

[0055] The processing unit may include one or more microprocessors of system 10 .

[0056] The waveform generator 13 may be an IQ sample player. The waveform generator 13 may be configured to receive waveform information in the form of an IQ data stream and dynamically adjust the RF output signal based on the IQ data stream.

[0057] The processing unit 14 may include a feedback interpreter 15 configured to generate and / or update a feedback configuration based on the feedback signal. The feedback configuration may include a plurality of consecutive segments, wherein each segment references or contains a portion of a corresponding stored or calculated waveform sample having a determined duration.

[0058] For example, the duration of the waveform sample portion in each segment may vary and may be adjusted by the feedback interpreter 15 .

[0059] Feedback interpreter 15 may continuously update the feedback configuration based on the feedback signal by adding new segments based on the current feedback signal, these new segments referencing or containing (parts of) waveform samples. The length of the waveform samples in each segment may determine the update rate of the feedback configuration.

[0060] The processing unit 14 may further include a feedback configurator 16 configured to map the feedback signal to a corresponding portion of the stored or calculated waveform samples for each segment based on a mapping rule and forward the mapping to the feedback interpreter 15. The feedback interpreter 15 then generates a feedback configuration based on the mapping.

[0061] The processing unit 14 or more specifically the feedback configurator 16 may include a preselector ( Figure 1 ), the preselector is configured to determine which waveform segments should be selected or calculated based on the feedback message.

[0062] The feedback configuration can be generated in the form of a configuration table based on the mapping. In the configuration table, commands received with the feedback signal are mapped to different waveform samples according to mapping rules. For example, the configuration table can reference waveform samples by their filename and storage location. Waveform samples can be stored as ".wv" files. Figure 3 An example of a mapping rule is shown.

[0063] For example, the configuration table is generated by the feedback configurator 16 and forwarded to the feedback interpreter 15 and / or directly to the sample provider 17 .

[0064] The sample provider 17 may be a component of the processing unit 14 that receives a feedback configuration (eg, in the form of a configuration table). The sample provider 17 may continuously receive feedback configurations while generating the feedback configuration based on the currently received feedback signal.

[0065] The sample provider 17 may then dynamically generate waveform information based on the portions of the stored or calculated waveform samples that are referenced in or contained by consecutive segments in the feedback configuration.

[0066] The sample provider 17 may be an IQ sample provider that generates waveform information in the form of an IQ data stream and forwards the IQ data stream to the waveform generator 13 .

[0067] The waveform generator 13 may include an IQ sample player configured to replay the IQ sample stream and generate and / or adjust the RF output signal based on the IQ sample stream.

[0068] In particular, the system 10 and the implemented feedback mechanism may be independent of: the type of RF output signal to be generated (e.g., the size of its segments, the type of waveform samples), the application (a generic solution based on ".wvs" samples rather than an application-specific solution), and the specification definition (a user may define custom scenarios by combining parts of waveform samples of various types and lengths).

[0069] Figure 2Generating an RF output signal from stored waveform samples is shown according to one embodiment.

[0070] For example, Figure 2 10. Three waveform samples (the top three signals) are provided in FIG. 10. In this example, each waveform sample is a 100 MHz signal provided in a ".wv" data format. These waveforms can be calculated or stored in the memory of system 10.

[0071] The feedback signal (herein referred to as a feedback message) may include a plurality of commands arranged in a specific order (e.g., 0, 1, (1), 2, etc., where (1) may indicate that no other feedback signals or commands have arrived, and therefore, continue with the segment of waveform 1). The processing unit 14, in particular the feedback interpreter 15 and / or the feedback configurator 16, may interpret these commands and assign each command to a segment having a specific time span, for example, based on a mapping rule that maps commands to corresponding waveform samples.

[0072] Figure 3 An exemplary mapping rule is shown. The length of the segment can be determined by the processing unit 14, in particular the feedback interpreter 15 and / or the feedback configurator 16, based on the feedback signal itself or based on user input. Figure 3 In the example shown, the segment length is 500 μs.

[0073] A composite waveform sample is formed by aligning corresponding parts of the waveform sample with the segment ( Figure 2 The composite waveform may correspond to waveform information and may define an RF output signal to be generated.

[0074] This waveform information may be forwarded to the waveform generator 13, which generates an RF output signal based on the composite waveform signal.

[0075] In summary, the system can switch its RF output between different waveforms (eg, provided in .wv files) based on a feedback signal. Thus, the system 10 can freely choose which waveforms to combine, how many waveforms to combine, and how to split the waveforms based on the feedback signal.

[0076] Figure 4 FIG. 2 shows a system 10 for testing a DUT 20 according to another embodiment. Figure 4 The exemplary system 10 shown may include: Figure 1 All components and functions of system 10 are shown.

[0077] DUT 20 may be a communication device capable of providing a feedback signal, such as a base station. DUT 20 may include an RF input port connected to RF output port 11 of system 10 to receive an RF output signal. DUT 20 may also include a communication interface communicatively connected to system interface 12 for forwarding the feedback signal.

[0078] The communication interface 12 may include a serial interface configured to receive the feedback signal at a serial data rate (eg, 1.92 Mbits / s).

[0079] Additionally or alternatively, the communication interface 12 may also include an Ethernet interface or an RF interface. If the interface is an Ethernet interface, the feedback signal may be a User Datagram Protocol (UDP) message. If the interface is an RF interface, the feedback signal may be a Downlink Control Information (DCI) message.

[0080] The feedback interpreter 15 may convert the input feedback signal into a feedback configuration, which is forwarded to the sample provider 17 .

[0081] The feedback configurator 16 may map the feedback signal to a pre-calculated sample file (e.g., a .wv file). Additionally or alternatively, the feedback configurator 16 may calculate a waveguide sample based on the feedback signal. This calculation of the waveguide sample(s) may be performed by a computation unit.

[0082] The feedback configurator 16 may be a "user interface" for mapping feedback signals to waveguide samples (e.g., NR5G files). The feedback configurator 16 may forward a table with this mapping to the feedback interpreter 15 and / or the sample provider 17. In the case of stored waveguide samples, these samples may be forwarded to the sample provider 17 together with a "mapping table."

[0083] The sample provider 17 may be an IQ sample creator 17 that may generate waveguide information in the form of an IQ data stream based on a feedback configuration. For example, the sample provider 17 may trigger real-time calculation of IQ samples based on a feedback configuration (e.g., a plugin-specific recall file) and forward the IQ samples to the IQ sample streamer 18. The sample provider 17 may also select stored IQ samples (e.g., a .wv file) based on the feedback configuration and forward the IQ samples to the IQ sample streamer 18.

[0084] The IQ sample streamer 18 may be a component of the processing unit 14 or the waveform generator 13 (e.g. Figure 4The waveform generator 13 may also include a digital-to-analog converter (DAC), for example in the form of a DAC IQ player 19.

[0085] The IQ sample streamer 18 may be configured to receive IQ samples in digital form from the sample provider 17 and write these samples to a shared memory with the DAC IQ player 19 or to forward the samples directly to the DAC IQ player 19, for example via a network interface.

[0086] The DAC IQ player 19 may convert the digital IQ data stream into an analog RF output signal.

[0087] The total delay of the sample provider 17 and the IQ sample streamer 18 can be less than 1NR time slot (less than 125μs for 5G applications). Selecting stored and pre-calculated samples and / or using a shared memory can reduce this delay.

[0088] The system 10 may further include an additional memory 21 configured to store waveform samples. The stored waveform samples may include waveform samples provided by a user or a third party and / or pre-calculated / pre-configured waveform samples.

[0089] The memory 21 may be another shared memory in the communication network. Thus, waveform data from different users or other entities may be stored in shared hardware.

[0090] The memory 21 may also include a buffer for storing pre-calculated waveforms.

[0091] The system may further comprise an access unit 22 for accessing the memory. The access unit 22 may be configured to select different stored waveform samples, eg to forward these samples to the sample provider 17.

[0092] The access unit 22 may also be configured to store new waveforms or waveform parts with different characteristics (particularly time span) in the memory 21. For example, this may be a waveform provided by a user for a specific application scenario.

[0093] The waveform generator 13 and the processing unit 14 may be integrated into a common device, which may be a radio frequency signal generator.

[0094] Alternatively, waveform generator 13 may be a standalone device communicatively connected to processing unit 14 (eg, a PC). Furthermore, processing unit 14 and various components of waveform generator 13 may also be distributed across various devices (streaming approach).

[0095] In the following, possible operation modes and use cases of the system 10 are discussed:

[0096] In general, standard and scenario-specific IQ segments / samples can be recalculated and stored in the memory 21 of the system 10 (e.g., in the arbitrary waveform memory ARB). This memory 21 can be shared between the host and the DSP of the processing unit 14. In addition, a table can be provided to the DSP that maps the addresses of these IQ segments / samples to the feedback signal. The DSP can interpret the feedback signal based on this mapping and write the results to a specific address area of the arbitrary waveform (ARB) player of the system 10 (e.g., the signal generator 13). This approach allows the configuration of the mapping of IQ samples (e.g., via a .wv file), segments (e.g., based on a list), and feedback messages, regardless of the specific use case or communication scenario.

[0097] Example 1: Pre-calculating waveform samples and receiving feedback signals on an external PC. The PC can include a feedback interpreter 15, a feedback configurator 16, an IQ sample provider 17, and an IQ sample streamer 18, and can forward the data to an IQ player 19, such as a VSG (player), via a high-speed Ethernet connection. This has the advantage that, due to streaming, the system 10 is not limited to a shared ARB memory (2.4 GHz samples). In addition, the IQ player 19 can be less complex. Waveform data can also be calculated in real time, which eliminates the need for pre-calculating the data. For example, in this case, the system 10 only provides a configuration for calculating waveform data in real time.

[0098] Example 2: The interface 12 and / or feedback interpreter 15 in the DSP can be implemented as an RF interface, such as an RF-DCI with feedback interpreter (e.g., a Universal Software Radio Peripheral (USRP)). This has the advantage that the DUT 20 does not need a dedicated interface (e.g., a serial interface) to send messages to the system interface 12. Instead, it can send "normal" DCI feedback messages through the existing RF output port.

[0099] System 10 can be used in the context of 5G testing, for example, for testing base stations. For example, the 5G test specifications include defined feedback scenarios that base stations must meet to be 3GPP compliant. The general feedback capabilities of system 10 can be used to further test such base stations in the early stages of base station development (e.g., for power adjustment, modulation adjustment, or precoding adjustment), prior to protocol testing.

[0100] Figure 5 A flow chart of a method 50 for testing a DUT 20 is shown according to one embodiment.

[0101] The method 50 includes the steps of generating 51 an RF output signal and forwarding the RF output signal to the DUT 20; receiving 52 a feedback signal from the DUT 20; dynamically generating 53 waveform information based on the received feedback signal, wherein the waveform information is generated based on stored and / or real-time calculated waveform samples; and adjusting 54 the RF output signal based on the waveform information.

[0102] Method 50 may be performed by, for example Figure 1 and Figure 4 The system 10 shown performs.

Claims

1. A system (10) for testing a device under test (DUT) (20), comprising: an output port (11) arranged to be connected to the DUT (20); a waveform generator (13) configured to generate a radio frequency output signal and forward the radio frequency output signal to the DUT (20) through the output port (11); a communication interface (12) configured to receive a feedback signal from the DUT (20); as well as a processing unit (14) configured to dynamically generate waveform information based on the received feedback signal, wherein the processing unit (14) is configured to generate the waveform information based on stored and / or real-time calculated waveform samples; The waveform generator (13) is configured to adjust the radio frequency output signal based on the waveform information.

2. The system (10) according to claim 1, in, The processing unit (14) comprises a feedback interpreter (15) configured to generate and / or update a feedback configuration based on the feedback signal, wherein the feedback configuration comprises a plurality of consecutive segments, wherein each segment references or contains a portion of a corresponding stored or calculated waveform sample having a determined duration.

3. The system (10) according to claim 2, in, The processing unit (14) comprises a feedback configurator (16) configured to map the feedback signal to a corresponding portion of a stored or calculated waveform sample based on a mapping rule for each segment and forward the mapping to the feedback interpreter (15); Wherein, the feedback interpreter (15) is configured to generate the feedback configuration based on the mapping.

4. The system (10) according to claim 3, in, The feedback configurator (16) is configured to calculate at least one waveform sample in real time based on the feedback message.

5. The system (10) according to any one of claims 2 to 4, in, The processing unit (14) further comprises a sample provider (17) configured to continuously receive the feedback configuration and dynamically generate the waveform information based on portions of stored or calculated waveform samples referenced in or included in consecutive segments in the feedback configuration.

6. The system (10) according to any one of claims 1 to 5, further comprising: A memory (21) is configured to store the stored waveform samples.

7. The system (10) according to claim 6, in, The memory (21) is a shared memory in the communication network.

8. System (10) according to claim 5 and claim 6 or 7, in, The system further comprises an access unit (22) for accessing the memory (21) and forwarding portions of stored waveform samples from the memory to the sample provider (17).

9. The system (10) according to claim 8, in, The access unit (22) is further configured to receive further waveform samples of different duration and / or with different characteristics and to store the further waveform samples in the memory (21).

10. The system (10) according to any one of claims 1 to 9, in, The communication interface (12) is a wireless or wired binding interface.

11. The system (10) according to any one of claims 1 to 10, in, The communication interface (12) is a serial interface configured to receive the feedback signal at a serial data rate.

12. The system (10) according to any one of claims 1 to 11, in, The waveform generator (13) includes an IQ sample stream transmitter (18) and / or a digital-to-analog converter.

13. The system (10) according to any one of claims 1 to 12, in, The waveform generator (13) and the processing unit (14) are integrated into a common device, or the waveform generator (13) is an independent device.

14. The system (10) according to any one of claims 1 to 13, in, The waveform generator (13) is configured to receive the waveform information in the form of an IQ data stream, wherein the waveform generator is configured to dynamically adjust the radio frequency output signal based on the IQ data stream.

15. System (10) according to any one of claims 1 to 14, in, The system (10) is a radio frequency signal generator.

16. A method (50) for testing a device under test (DUT) (20), comprising: generating (51) a radio frequency output signal and forwarding the radio frequency output signal to the DUT (20); receiving (52) a feedback signal from the DUT (20); dynamically generating (53) waveform information based on the received feedback signal, wherein the waveform information is generated based on stored and / or real-time calculated waveform samples; as well as The radio frequency output signal is adjusted (54) based on the waveform information.

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