WO2024016252A1

WO2024016252A1 - Testing millimeter wave devices with multiple receive chains

Info

Publication number: WO2024016252A1
Application number: PCT/CN2022/106989
Authority: WO
Inventors: Bin Han; Sumant Jayaraman IYER; Valentin Alexandru Gheorghiu; Gaurav Nigam; Changhwan Park; Yiqing Cao
Original assignee: Qualcomm Incorporated
Priority date: 2022-07-21
Filing date: 2022-07-21
Publication date: 2024-01-25

Abstract

Techniques related to testing a frequency range 2 (FR2) user equipment (UE) are disclosed. Some aspects of the disclosure relate to devices and methods for determining a first over-the-air (OTA) angle of arrival (AoA) for a first beam based on a first signal quality measurement of the first beam, and while fixing the first OTA AoA, determining a second OTA AoA for a second beam based on a second signal quality measurement of the second beam. Further aspects of the disclosure relate to devices and methods for equalizing a channel matrix of an OTA channel of a test chamber based on cross-interference between the first beam and the second beam, and based on cross-interference between a plurality of polarizations within each of the first beam and the second beam. Other aspects, embodiments, and features are also claimed and described.

Description

TESTING MILLIMETER WAVE DEVICES WITH MULTIPLE RECEIVE CHAINS

TECHNICAL FIELD

The technology discussed below relates generally to wireless communication systems, and more particularly, to testing demodulation performance of millimeter wave devices with multiple receive chains.

INTRODUCTION

The 3 ^rd Generation Partnership Project (3GPP) defines minimum performance requirements for user equipment (UE) to be compliant with standards for 5G New Radio (NR) . A given UE conforms with the specified performance requirements when it can demonstrate that it fulfills a set of specified tests. Among these tests is included a set of tests for demodulation performance for frequency range 2 (FR2) , defined as frequencies between 24.25–52.60 GHz (more commonly known as millimeter-wave, or mmWave wavelength) .

As the functions and capabilities of mobile devices continue to develop, testing methods and procedures continue to be updated for testing a variety of features.

BRIEF SUMMARY OF SOME EXAMPLES

The following presents a summary of one or more aspects of the present disclosure, to provide a basic understanding of such aspects. This summary is not an extensive overview of all contemplated features of the disclosure, and is intended neither to identify key or critical elements of all aspects of the disclosure nor to delineate the scope of any or all aspects of the disclosure. Its sole purpose is to present some concepts of one or more aspects of the disclosure in a simplified form as a prelude to the more detailed description that is presented later. While some examples may be discussed as including certain aspects or features, all discussed examples may include any of the discussed features. Unless expressly described, no one aspect or feature is essential to achieve technical effects or solutions discussed herein.

In various aspects, the present disclosure provides for systems and procedures for testing downlink demodulation performance for wireless communication devices configured for operating in frequency range 2 (FR2) with multiple receive chains, and/or configured for 4-layer multiple-input multiple-output (MIMO) operation. In some examples, systems and procedures for finding two test directions or angles of arrival (AoA) are disclosed, in particular, for beams that each include two polarizations. In further examples, systems and procedures for equalizing a channel matrix of an over-the-air (OTA) channel of a test chamber based on cross-interference between the respective beams are disclosed.

In one example a test apparatus for testing a device under test (DUT) positioned in a test chamber is disclosed. The test apparatus includes a processor, a memory coupled to the processor, a first test antenna probe coupled to the processor, and a second test antenna probe coupled to the processor. The processor is configured to determine a first over-the-air (OTA) angle of arrival (AoA) for a first beam directed from the first antenna probe to the DUT, based on a first signal quality measurement of the first beam. The processor is further configured to: while fixing the first OTA AoA, determine a second OTA AoA for a second beam directed from the second antenna probe to the DUT, based on a second signal quality measurement of the second beam. The processor is further configured to equalize a channel matrix of an OTA channel of the test chamber based on cross-interference between the first beam and the second beam, and based on cross-interference between a plurality of polarizations within each of the first beam and the second beam.

In another example a method for testing a device under test (DUT) positioned in a test chamber is disclosed. The method includes determining a first over-the-air (OTA) angle of arrival (AoA) for a first beam directed to the DUT, based on a first signal quality measurement of the first beam. The method further includes: while fixing the first OTA AoA, determining a second OTA AoA for a second beam directed to the DUT, based on a second signal quality measurement of the second beam. The method further includes equalizing a channel matrix of an OTA channel of the test chamber based on cross-interference between the first beam and the second beam, and based on cross-interference between a plurality of polarizations within each of the first beam and the second beam.

In still another example a test apparatus for testing a device under test (DUT) positioned in a test chamber is disclosed. The test apparatus includes means for determining a first over-the-air (OTA) angle of arrival (AoA) for a first beam directed to the DUT, based on a first signal quality measurement of the first beam. The test apparatus further includes means for: while fixing the first OTA AoA, determining a second OTA AoA for a second beam directed to the DUT, based on a second signal quality measurement of the second beam. The test apparatus further includes means for equalizing a channel matrix of an OTA channel of the test chamber based on cross-interference between the first beam and the second beam, and based on cross-interference between a plurality of polarizations within each of the first beam and the second beam.

In yet another example, a non-transitory computer-readable medium storing computer-executable code is disclosed. The computer-executable code includes instructions for causing a test apparatus for testing a device under test (DUT) positioned in a test chamber, to determine a first over-the-air (OTA) angle of arrival (AoA) for a first beam directed from the first antenna probe to the DUT, based on a first signal quality measurement of the first beam. The computer-executable code further includes instructions for causing the test apparatus to: while fixing the first OTA AoA, determine a second OTA AoA for a second beam directed from the second antenna probe to the DUT, based on a second signal quality measurement of the second beam. The computer-executable code further includes instructions for causing the test apparatus to equalize a channel matrix of an OTA channel of the test chamber based on cross-interference between the first beam and the second beam, and based on cross-interference between a plurality of polarizations within each of the first beam and the second beam.

These and other aspects of the technology discussed herein will become more fully understood upon a review of the detailed description, which follows. Other aspects and features will become apparent to those of ordinary skill in the art, upon reviewing the following description of specific examples in conjunction with the accompanying figures. While the following description may discuss various advantages and features relative to certain examples, implementations, and figures, all examples can include one or more of the advantageous features discussed herein. In other words, while this description may discuss one or more examples as having certain advantageous features, one or more of such features may also be used in accordance with the other various examples discussed herein. In similar fashion, while this description may discuss certain examples as devices, systems, or methods, it should be understood that such examples of the teachings of the disclosure can be implemented in various devices, systems, and methods.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic illustration of a wireless communication system according to some aspects of this disclosure.

FIG. 2 is a block diagram illustrating a wireless communication system supporting multiple-input multiple-output (MIMO) communication according to some aspects of this disclosure.

FIG. 3 is a block diagram illustrating channel characteristics of a test apparatus and mmWave chamber according to some aspects of this disclosure.

FIG. 4 is a schematic illustration of an example of a spherical grid of angles of arrival (AoAs) that may be provided by different probe antenna configurations in a test chamber according to some aspects of this disclosure.

FIG. 5 is a schematic illustration of different AoAs according to some aspects of this disclosure.

FIG. 6 is a flow chart illustrating an example of a process for testing a mmWave device according to some aspects of this disclosure.

FIG. 7 is a flow chart illustrating an example of a process for equalizing an over-the-air (OTA) channel according to some aspects of this disclosure.

FIG. 8 is a block diagram conceptually illustrating an example of a hardware implementation for a test apparatus according to some aspects of this disclosure.

DETAILED DESCRIPTION

In some aspects, the present disclosure relates to systems, methods, and procedures for testing millimeter-wave (mmWave) devices. Illustrative examples described herein involve a device under test (DUT) that is a wireless user equipment (UE) configured for operation in frequency range 2 (FR2) , between 24.25–52.60 GHz. However, aspects of the test systems and procedures described herein may be applicable to other RF testing, such as frequency range 1 (FR1) testing or testing of frequencies greater than those currently encompassed by FR2. Further illustrative examples in the present disclosure provide testing systems and procedures for a DUT having multiple receiver (Rx) panels operating with 4-layer multiple-input multiple-output (MIMO) .

Current specifications for new radio (NR or 5G technology) specify demodulation performance testing for FR2 devices for up to two-layer MIMO. However, to test demodulation performance for four-layer MIMO in FR2 devices, new test procedures are desired.

Prior to discussing RF testing systems and procedures, an overview of a wireless communication system in which one or more UEs may be used is provided. This overview is provided, in part, to describe the signals an antenna array of a UE or other wireless communication device may transmit or receive and/or the environment in which the UE may operate (for which testing may be needed) .

Referring now to FIG. 1, as an illustrative example without limitation, this schematic illustration shows various aspects of the present disclosure with reference to a wireless communication system 100. The wireless communication system 100 includes several interacting domains: a core network 102, a radio access network (RAN) 104, and a user equipment (UE) 106. By virtue of the wireless communication system 100, the UE 106 may be enabled to carry out data communication with an external data network 110, such as (but not limited to) the Internet.

The RAN 104 may implement any suitable wireless communication technology or technologies to provide radio access to the UE 106. As one example, the RAN 104 may operate according to 3rd Generation Partnership Project (3GPP) New Radio (NR) specifications, often referred to as 5G or 5G NR. In some examples, the RAN 104 may operate under a hybrid of 5G NR and Evolved Universal Terrestrial Radio Access Network (eUTRAN) standards, often referred to as Long-Term Evolution (LTE) . 3GPP refers to this hybrid RAN as a next-generation RAN, or NG-RAN. Of course, many other examples may be utilized within the scope of the present disclosure.

As illustrated, the RAN 104 includes a plurality of base stations 108. Broadly, a base station is a network element in a radio access network responsible for radio transmission and reception in one or more cells to or from a UE. In different technologies, standards, or contexts, those skilled in the art may variously refer to a “base station” as a base transceiver station (BTS) , a radio base station, a radio transceiver, a transceiver function, a basic service set (BSS) , an extended service set (ESS) , an access point (AP) , a Node B (NB) , an evolved Node B (eNB) , a gNode B (gNB) , a 5G NB, a transmit receive point (TRP) , or some other suitable terminology.

The radio access network (RAN) 104 supports wireless communication for multiple mobile apparatuses. Those skilled in the art may refer to a mobile apparatus as a UE, as in 3GPP specifications, but may also refer to a UE as a mobile station (MS) , a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communication device, a remote device, a mobile subscriber station, an access terminal (AT) , a mobile terminal, a wireless terminal, a remote terminal, a handset, a terminal, a user agent, a mobile client, a client, or some other suitable terminology. A UE may be an apparatus that provides access to network services. A UE may take on many forms and can include a range of devices.

Within the present document, a “mobile” apparatus (aka a UE) need not necessarily have a capability to move, and may be stationary. The term mobile apparatus or mobile device broadly refers to a diverse array of devices and technologies. UEs may include a number of hardware structural components sized, shaped, and arranged to help in communication; such components can include antennas, antenna arrays, RF chains, amplifiers, one or more processors, etc. electrically coupled to each other. For example, some non-limiting examples of a mobile apparatus include a mobile, a cellular (cell) phone, a smart phone, a session initiation protocol (SIP) phone, a laptop, a personal computer (PC) , a notebook, a netbook, a smartbook, a tablet, a personal digital assistant (PDA) , and a broad array of embedded systems, e.g., corresponding to an “Internet of things” (IoT) . A mobile apparatus may additionally be an automotive or other transportation vehicle, a remote sensor or actuator, a robot or robotics device, a satellite radio, a global positioning system (GPS) device, an object tracking device, a drone, a multi-copter, a quad-copter, a remote control device, a consumer and/or wearable device, such as eyewear, a wearable camera, a virtual reality device, a smart watch, a health or fitness tracker, a digital audio player (e.g., MP3 player) , a camera, a game console, etc. A mobile apparatus may additionally be a digital home or smart home device such as a home audio, video, and/or multimedia device, an appliance, a vending machine, intelligent lighting, a home security system, a smart meter, etc. A mobile apparatus may additionally be a smart energy device, a security device, a solar panel or solar array, a municipal infrastructure device controlling electric power (e.g., a smart grid) , lighting, water, etc. ; an industrial automation and enterprise device; a logistics controller; and agricultural equipment; etc. Still further, a mobile apparatus may provide for connected medicine or telemedicine support, e.g., health care at a distance. Telehealth devices may include telehealth monitoring devices and telehealth administration devices, whose communication may be given preferential treatment or prioritized access over other types of information, e.g., in terms of prioritized access for transport of critical service data, and/or relevant QoS for transport of critical service data. A mobile apparatus may additionally include two or more disaggregated devices in communication with one another, including, for example, a wearable device, a haptic sensor, a limb movement sensor, an eye movement sensor, etc., paired with a smartphone. In various examples, such disaggregated devices may communicate directly with one another over any suitable communication channel or interface, or may indirectly communicate with one another over a network (e.g., a local area network or LAN) .

Wireless communication between a RAN 104 and a UE 106 may be described as utilizing an air interface. Transmissions over the air interface from a base station (e.g., base station 108) to one or more UEs (e.g., UE 106) may be referred to as downlink (DL) transmission. In accordance with certain aspects of the present disclosure, the term downlink may refer to a point-to-multipoint transmission originating at a scheduling entity (described further below; e.g., network node 108) . Another way to describe this scheme may be to use the term broadcast channel multiplexing. Transmissions from a UE (e.g., UE 106) to a base station (e.g., base station 108) may be referred to as uplink (UL) transmissions. In accordance with further aspects of the present disclosure, the term uplink may refer to a point-to-point transmission originating at a scheduled entity (described further below; e.g., UE 106) .

In some examples, access to the air interface may be scheduled, wherein a scheduling entity (e.g., a network node 108) allocates resources for communication among some or all devices and equipment within its service area or cell. Within the present disclosure, as discussed further below, a scheduling entity may be responsible for scheduling, assigning, reconfiguring, and releasing resources for one or more scheduled entities. That is, for scheduled communication, UEs 106, which may be scheduled entities, may utilize resources allocated by a scheduling entity 108.

Base stations are not the only entities that may function as scheduling entities. That is, in some examples, a UE or network node may function as a scheduling entity, scheduling resources for one or more scheduled entities (e.g., one or more UEs) .

As illustrated in FIG. 1, a network node 108 may broadcast downlink traffic 112 to one or more UEs 106. Broadly, the network node 108 is a node or device responsible for scheduling traffic in a wireless communication network, including downlink traffic 112 and, in some examples, uplink traffic 116 from one or more UEs 106 to the network node 108. On the other hand, the UE 106 is a node or device that receives downlink control information 114, including but not limited to scheduling information (e.g., a grant) , synchronization or timing information, or other control information from another entity in the wireless communication network such as the network node 108.

In general, network nodes 108 may include a backhaul interface for communication with a backhaul portion 120 of the wireless communication system. The backhaul 120 may provide a link between a network node 108 and the core network 102. Further, in some examples, a backhaul network may provide interconnection between the respective network nodes 108. Various types of backhaul interfaces may be employed, such as a direct physical connection, a virtual network, or the like using any suitable transport network.

The core network 102 may be a part of the wireless communication system 100 and may be independent of the radio access technology used in the RAN 104. In some examples, the core network 102 may be configured according to 5G standards (e.g., 5GC) . In other examples, the core network 102 may be configured according to a 4G evolved packet core (EPC) , or any other suitable standard or configuration.

Wireless transmissions to or from a UE may carry one or more physical channels, including control channels, shared channels, data channels, etc. Other transmissions may also carry pilots or reference signals. These pilots or reference signals may provide for a receiving device to perform channel estimation of the corresponding channel, which may enable coherent demodulation/detection of the control and/or data channels.

In a downlink transmission, the transmitting device (e.g., a network node 108) may allocate suitable resources to carry one or more downlink control channels. These downlink control channels include downlink control information 114 (DCI) that generally carries information originating from higher layers, such as a physical broadcast channel (PBCH) , a physical downlink control channel (PDCCH) , etc., to one or more UEs 106. In addition, the network node may allocate suitable downlink resources to carry downlink physical signals that generally do not carry information originating from higher layers. These downlink physical signals may include a primary synchronization signal (PSS) ; a secondary synchronization signal (SSS) ; demodulation reference signals (DM-RS) ; phase-tracking reference signals (PT-RS) ; channel-state information reference signals (CSI-RS) ; etc.

A network node may transmit the synchronization signals PSS and SSS (collectively referred to as SS) , and in some examples, the PBCH, in an SS block.

The PDCCH may carry downlink control information (DCI) for one or more UEs in a cell. This can include, but is not limited to, power control commands, scheduling information, a grant, and/or an assignment of resources for downlink and uplink transmissions.

In an uplink transmission, a transmitting device (e.g., a UE 106) may utilize suitable resources to carry one or more uplink control channels, such as a physical uplink control channel (PUCCH) , a physical random access channel (PRACH) , etc. These uplink control channels include uplink control information 118 (UCI) that generally carries information originating from higher layers. Further, uplink resources may carry uplink physical signals that generally do not carry information originating from higher layers, such as demodulation reference signals (DM-RS) , phase-tracking reference signals (PT-RS) , sounding reference signals (SRS) , etc. In some examples, the control information 118 may include a scheduling request (SR) , i.e., a request for the network node 108 to schedule uplink transmissions. Here, in response to the SR transmitted on the UL control channel 118 (e.g., a PUCCH) , the network node 108 may transmit downlink control information (DCI) 114 that may schedule resources for uplink packet transmissions.

In addition to control information, wireless resources may be allocated for user data or traffic data. Such traffic may be carried on one or more traffic channels, such as, for a downlink transmission, a physical downlink shared channel (PDSCH) ; or for an uplink transmission, a physical uplink shared channel (PUSCH) .

The channels or carriers described above are not necessarily all the channels or carriers that may be utilized between a network node 108 and UE 106, and those of ordinary skill in the art will recognize that other channels or carriers may be utilized in addition to those illustrated, such as other traffic, control, and feedback channels.

In some aspects of the disclosure, a network node and/or UE may be configured with multiple antennas for beamforming and/or multiple-input multiple-output (MIMO) technology. FIG. 2 illustrates an example of a wireless communication system 200 with multiple antennas, supporting beamforming and/or MIMO. The use of such multiple antenna technology enables the wireless communication system to exploit the spatial domain to support spatial multiplexing, beamforming, and transmit diversity.

Beamforming generally refers to directional signal transmission or reception. For a beamformed transmission, a transmitting device may precode, or control the amplitude and phase of each antenna in an array of antennas to create a desired (e.g., directional) pattern of constructive and destructive interference in the wavefront. In a MIMO system, a transmitter 202 includes multiple transmit antennas 204 (e.g., N transmit antennas) and a receiver 206 includes multiple receive antennas 208 (e.g., M receive antennas) . Thus, there are N × M signal paths 210 from the transmit antennas 204 to the receive antennas 208. Each of the transmitter 202 and the receiver 206 may be implemented, for example, within a scheduling entity 108, a scheduled entity 106, or any other suitable wireless communication device.

In a MIMO system, spatial multiplexing may be used to transmit multiple different streams of data, also referred to as layers, simultaneously on the same time-frequency resource. In some examples, a transmitter 202 may send multiple data streams to a single receiver. In this way, a MIMO system takes advantage of capacity gains and/or increased data rates associated with using multiple antennas in rich scattering environments where channel variations can be tracked. Here, the receiver 206 may track these channel variations and provide corresponding feedback to the transmitter 202. In one example case, as shown in FIG. 2, a rank-2 (i.e., including 2 data streams) spatial multiplexing transmission on a 2x2 MIMO antenna configuration will transmit two data streams via two transmit antennas 204. The signal from each transmit antenna 204 reaches each receive antenna 208 along a different signal path 210. The receiver 206 may then reconstruct the data streams using the received signals from each receive antenna 208.

A receiver (e.g., receiver 206) may transmit feedback including a quantized version of the channel so that the transmitter 202 can schedule the receiver with good channel separation between layers. The spatially precoded data streams arrive at the receiver with different spatial signatures, which enables the receiver (in some examples, in combination with known channel state information) to separate these streams from one another and recover the data streams destined for that receiver.

The number of data streams or layers in a MIMO or MU-MIMO (generally referred to as MIMO) system corresponds to the rank of the transmission. In general, the rank of a MIMO system is limited by the number of transmit or receive

antennas

204 or 208, whichever is lower. In addition, the channel conditions at the receiver 206, as well as other considerations, such as the available resources at the transmitter 202, may also affect the transmission rank.

The transmitter 202 determines the precoding of the transmitted data stream or streams based, e.g., on known channel state information of the channel on which the transmitter 202 transmits the data stream (s) . For example, the transmitter 202 may transmit one or more suitable reference signals (e.g., a channel state information reference signal, or CSI-RS) that the receiver 206 may measure. The receiver 206 may then report measured channel quality information (CQI) back to the transmitter 202. This CQI generally reports the current communication channel quality, and in some examples, a requested transport block size (TBS) for future transmissions to the receiver. In some examples, the receiver 206 may further report a precoding matrix indicator (PMI) to the transmitter 202. This PMI generally reports the receiver’s 206 preferred precoding matrix for the transmitter 202 to use and may be indexed to a predefined codebook. The transmitter 202 may then utilize this CQI/PMI to determine a suitable precoding matrix for transmissions to the receiver 206.

Turning now to FIG. 3, aspects of an exemplary test apparatus and methods for testing demodulation performance for an FR2 UE with multiple receive panels are described. FIG. 3 schematically illustrates a channel as seen by a signal transmitted from a signal generator to a UE/DUT 310. For example, a signal generator may generate a desired signal and noise 302. The baseband portion of a set of test equipment 304 may affect the channel in a known manner, and the RF portion of a set of test equipment 306 may also affect the channel in a known manner. A UE 310 (DUT) is positioned in a mmWave chamber 312 having a chamber over-the-air channel 308. The chamber 312 may be referred to as an OTA chamber, an FR2 chamber, an antenna measurement chamber, a test chamber, or any other suitable terminology. The chamber 312 may include a plurality of antenna probe configurations providing for testing beams from multiple angles of arrival (AoA) to the DUT. For example, FIG. 4 illustrates an example of a spherical grid of AoAs (illustrated by the points 402) that may be provided by different probe antenna configurations in a test chamber 312. The AoA may be the angle of arrival of a signal coming from test equipment. The AoA of a downlink transmission, from the UE point of view, may be referred to as the link angle.

According to some aspects of this disclosure, the UE/DUT 310 may be configured with a plurality of receive chains operable in FR2, and the test apparatus may be configured for testing UE demodulation performance under 4-layer downlink MIMO.

For a given subcarrier in the frequency domain, the baseband equivalent description of the signal model is as follows

Y=H _chamber· (H·P·X+N)

Here, H _chamber is the matrix that represents the quasi-static chamber OTA channel. H represents the baseband channel applied by the testing equipment. H is an empirical value based on the channel model of test cases. P represents the baseband precoding matrix applied to the signal, and X represents the vector of the baseband transmission signal. N represents the artificial noise vector added in baseband to control the signal-to-noise ratio (SNR) .

When the UE 310 is placed within the test chamber 312, the frequency response H _chamber of the test chamber 312 can adversely affect the UE measurements. Therefore, to remove the impact of the OTA chamber channel, a procedure for equalizing the OTA channel may be performed. In some examples, the equalizing procedure may be based on UE feedback of channel information, such as reference signal received power (RSRP) and/or reference signal antenna relative phase (RSARP) reporting. Based on this UE feedback, the inverse of the chamber OTA channel, denoted as

may be estimated according to the equation:

where

is the Hermitian transpose (i.e., the conjugate transpose) of the estimated OTA channel H _chamber.

Once the inverse of the chamber OTA channel is estimated, the OTA channel may be equalized as follows:

Current specifications for NR specify demodulation performance testing for FR2 devices for up to two-layer MIMO. However, to test demodulation performance for four-layer MIMO in FR2 devices, new test procedures are desired. For example, with reference to FIG. 5, currently specified testing procedures consider only a single AoA 502. However, for 4-layer downlink MIMO as illustrated at 504, the signals arrive from two AoAs (AoA1 and AoA2) . Thus, some aspects of this disclosure provide for a testing procedure to identify two AoAs for a demodulation performance test.

Further, currently specified channel equalizing procedures only account for a single beam 502. That is, testing procedures only need UE reporting of RSRP/RSARP values within one beam, between two polarizations. Therefore, further aspects of this disclosure provide inter-beam and intra-beam characterization. Here, inter-beam refers to the correlation between two beams (e.g., AoA1 and AoA2) , and intra-beam refers to the correlation between two polarizations of the same beam.

FIG. 6 is a flow chart illustrating an exemplary process 600 for testing a mmWave device in accordance with some aspects of the present disclosure. As described below, a particular implementation may omit some or all illustrated features, and may not require some illustrated features to implement all embodiments. In some examples, the test apparatus 800 illustrated in FIG. 8 may be configured to carry out the process 600. In some examples, any suitable apparatus or means for carrying out the functions or algorithm described below may carry out the process 600.

At block 602, a device under test (DUT) , such as a wireless UE, may be positioned in a test chamber. The test chamber may be any suitable chamber, and in some examples is characterized as an OTA chamber having an OTA channel matrix. The DUT may be positioned within the test chamber in a known orientation such that an AoA of an incoming beam can be repeatable and reproducible.

At block 604, the test apparatus may determine a first OTA AoA for a first beam directed to the DUT, based on a first signal quality measurement of the first beam. And at block 606, while fixing the first OTA AoA, the test apparatus may determine a second OTA AoA for a second beam directed to the DUT, based on a second signal quality measurement of the second beam. Here, fixing the first OTA AoA refers to retaining the first beam at the selected grid point during the time when scanning for the second OTA AoA.

Blocks

604 and 606 may be performed utilizing a variety of different procedures. Two such procedures are described below: an EIS-based approach and an RSRPB-based approach.

EIS-Based Approach

Block 604: Once the DUT is positioned in the test chamber, the test apparatus may configure the UE/DUT for a first beam, or transmission configuration indication (TCI) state (TCI1) . TCI states are parameters configured at the UE that include information about a reference signal, such as a CSI-RS or an SS block. By associating a downlink test transmission with a certain TCI, the test apparatus can inform the UE/DUT that it can assume the forthcoming downlink transmission uses the same spatial filter (beam) as the reference signal associated with that TCI. The test apparatus may then find the RX beam peak direction by employing a 3D effective isotropic sensitivity (EIS) scan over a given set of search grid points. That is, at each grid point 402 (see, e.g., FIG. 4) , for a given polarization, the test apparatus may determine the EIS at which the throughput exceeds a given threshold by sweeping the downlink power level for that polarization. For a dual polarization beam, the test apparatus may calculate an average EIS based on the measured EIS for each polarization. The RX beam peak direction is the direction where the minimum average EIS is found. Once the RX beam peak direction is found, this direction corresponds to a first AoA.

Block 606: to find a second AoA, the test apparatus may configure the UE/DUT for a second beam, or TCI state (TCI2) . The test apparatus may then fix the first AoA and scan for the second AoA by employing a 3D EIS scan over a set of search grid points in a 3D test grid around the UE/DUT. That is, at each grid point 402, for a given polarization, the test apparatus may determine the EIS at which the throughput exceeds a given threshold by sweeping the downlink power level for that polarization. For a dual polarization beam, the test apparatus may calculate an average EIS based on the measured EIS for each polarization. The RX beam peak direction is the direction where the minimum average EIS is found. Once the RX beam peak direction is found, this direction corresponds to a second AoA.

RSRPB-Based Approach

Block 604: Once the DUT is positioned in the test chamber, the test apparatus may configure the UE/DUT for a first beam, or TCI state (TCI1) . The test apparatus may then enable periodic RSRP/RSRPB reporting from the UE/DUT. The test apparatus may then find a set (e.g., a plurality) of candidate RX beam peak directions by employing a 3D RSRP/RSRPB scan over a given set of search grid points. That is, at each grid point 402, the test apparatus may record the RSRP/RSRPB reported by the UE/DUT for each polarization. The test apparatus may then sort or rank the grid points based on the sum of 4 RSRP/RSRPB values per grid point (i.e., 2 each for each polarization) . The test apparatus may then select a set (e.g., 5, or any suitable number) of candidate RX beam peak directions according to their ranking. Here, the test apparatus may select a plurality of candidate RX beam peak directions, rather than selecting the highest peak, because UE reporting of RSRP/RSRPB measurements are configured at the UE and may be less accurate than use of the EIS-based approach. Once the set of candidate RX beam peak directions is found, these directions correspond to candidates for a first AoA.

Block 606: to find a second AoA, the test apparatus may configure the UE/DUT for a second beam, or TCI state (TCI2) . For each candidate for the first AoA, the test apparatus may fix the first AoA and scan for the second AoA by employing a 3D EIS scan over a set of search grid points in a 3D test grid around the UE/DUT. That is, at each grid point 402, the test apparatus may record the RSRPB reported by the UE/DUT for each polarization. The test apparatus may then sort or rank the grid points based on the sum of 4 RSRPB values per grid point (i.e., 2 each for each polarization) . The test apparatus may then select a set (e.g., 5, or any suitable number) of candidate RX beam peak directions according to their ranking. Once the set of candidate RX beam peak directions is found, these directions correspond to candidates for a second AoA.

Thus, in the example given above where the top 5 beam directions are selected as candidates for both the first and second AoA, these scans result in a total of 25 candidate pairs of AoAs. As an optional step 608, these candidate pairs can be narrowed down by determining whether the isolation between the respective pair of beams is greater than a suitable minimum threshold isolation, and eliminating as a candidate pair any pair that does not meet this minimum threshold isolation. In some examples, the isolation may be determined corresponding to an RSRPB measurement from one polarization/branch to the other within a beam. In some other examples, the isolation may be determined corresponding to an RSRPB measurement from one beam to the other. At block 610, the set of candidate pairs can be further narrowed down by determining whether each respective pair passes a reference receive sensitivity (REFSENS) test. The REFSENS power level is defined as the EIS level at the UE antenna in the RX beam peak directions at which the throughput meets or exceeds specified throughput requirements for the reference measurement channel. The REFSENS test may require the UE to reach a target throughput with a predefined modulation and coding scheme with a specified REFSENS power level.

While the RSRPB-based approach includes a greater number of measurements than the EIS-based approach, RSRPB searching is much more rapid than EIS searching. Thus, overall, the RSRPB-based approach can be performed more quickly than the EIS-based approach.

Equalizing the OTA Channel

At block 612, once AoA1 and AoA2 are identified, the test apparatus may equalize the OTA channel based on cross-interference between the first beam and the second beam, and based on cross-interference between the polarizations within each of the first beam and the second beam. Details of block 612 are provided in FIG. 7. That is, FIG. 7 is a flow chart illustrating an exemplary process 612 for equalizing an OTA channel in accordance with some aspects of this disclosure. As described below, a particular implementation may omit some or all illustrated features, and may not require some illustrated features to implement all embodiments. In some examples, the test apparatus 800 illustrated in FIG. 8 may be configured to carry out the process 612. In some examples, any suitable apparatus or means for carrying out the functions or algorithm described below may carry out the process 612.

At block 702, the test apparatus may configure the UE/DUT for a first beam/TCI state (TCI1) , and may transmit a downlink reference signal (e.g., SS or CSI-RS) utilizing the first beam/AoA corresponding to the first TCI state TCI1. Thus, the UE may report a quality of the first beam (e.g., RSRPB and RSARP) between a plurality of polarizations while configured for receiving the first beam. In this manner, the test apparatus may obtain the correlation or impact between two polarizations on the first beam, including both amplitude and phase information.

At block 704, the test apparatus may configure the UE/DUT for a second beam/TCI state (TCI2) , and may transmit a downlink reference signal (e.g., SS or CSI-RS) utilizing the second beam/AoA corresponding to the second TCI state TCI2. Thus, the UE may report a quality of the second beam (e.g., RSRPB and RSARP) between a plurality of polarizations while configured for receiving the second beam. In this manner, the test apparatus may obtain the correlation or impact between two polarizations on the second beam, including both amplitude and phase information.

At block 706, the test apparatus may configure the UE/DUT for the first beam/TCI state (TCI1) , and may transmit a downlink reference signal (e.g., SS or CSI-RS) utilizing the second beam/AoA corresponding to the second TCI state TCI2. Thus, the UE may report a quality of the second beam (e.g., RSRPB and RSARP) between a plurality of polarizations while configured for receiving the first beam. In this manner, the test apparatus may obtain the correlation or impact between the two beams, including both amplitude and phase information.

At block 708, the test apparatus may configure the UE/DUT for the second beam/TCI state (TCI2) , and may transmit a downlink reference signal (e.g., SS or CSI-RS) utilizing the first beam/AoA corresponding to the first TCI state TCI1. Thus, the UE may report a quality of the first beam (e.g., RSRPB and RSARP) between a plurality of polarizations while configured for receiving the second beam. In this manner, the test apparatus may obtain the correlation or impact between the two beams, including both amplitude and phase information.

In various examples, blocks 702, 704, 706, and 708 may be performed in sequence, or may be performed sequentially (e.g., one-by-one) . Further, in some examples, blocks 702, 704, 706, and 708 may be triggered by multiple TCI states.

At block 710, the test apparatus may construct the OTA channel of the test chamber H _chamber. The channel H _chamber is a 4x4 matrix populated with the values straightforwardly from the UE reporting values described above. For example, if layers 1 and 2 correspond to beam 1, and layers 3 and 4 correspond to beam 2, then the channel matrix H _chamber may be constructed as follows:

Here, H _ij represents the channel coefficient from layer i to layer j consisting of amplitude and phase. The amplitude of the channel coefficients may be based on the RSRPB reporting, and the phase may be based on the RSARP reporting.

At block 712, the test apparatus may estimate the inverse of the channel matrix

as described above. For example:

At block 714, the test apparatus may equalize the OTA chamber channel as described above. That is, by multiplying the inverse of the channel matrix

the impact of the OTA chamber channel can be equalized. In other words, an identity matrix may be obtained by multiplying

resulting in the following:

Returning to FIG. 6, at block 614, the test apparatus may perform an isolation check across dual polarizations and across dual beams. For example, the test apparatus may first determine whether the isolation between two polarizations within one beam is greater than a first minimum threshold isolation. The test apparatus may then determine whether the isolation between two beams (i.e., the isolation between any polarization from the two beams) is greater than a second minimum threshold isolation. Here, the first and second minimum threshold isolation values may be the same or may differ from one another. To determine the isolation between polarizations of a beam or between beams, the test apparatus may transmit a test signal in the desired test direction with a pre-defined downlink power level. The test apparatus may then perform the isolation of the branches, e.g., utilizing an inverse channel matrix approach as detailed in 3GPP TS 38.101-3. Once the isolation is determined, the test apparatus may verify that the isolation is greater than the above-described minimum threshold isolation value.

FIG. 8 is a block diagram illustrating an example of a hardware implementation for a test apparatus 800 employing a processing system 814. For example, the test apparatus 800 may include a test equipment baseband 304 and test equipment RF 306 as illustrated in FIG. 3.

The test apparatus 800 may include a processing system 814 having one or more processors 804. Examples of processors 804 include microprocessors, microcontrollers, digital signal processors (DSPs) , field programmable gate arrays (FPGAs) , programmable logic devices (PLDs) , state machines, gated logic, discrete hardware circuits, and other suitable hardware configured to perform the various functionality described throughout this disclosure. In various examples, the network node 800 may be configured to perform any one or more of the functions described herein. For example, the processor 804, as utilized in a test apparatus 800, may be configured (e.g., in coordination with the memory 805) to implement any one or more of the processes and procedures described above and illustrated in FIGs. 6 and 7.

The processing system 814 may be implemented with a bus architecture, represented generally by the bus 802. The bus 802 may include any number of interconnecting buses and bridges depending on the specific application of the processing system 814 and the overall design constraints. The bus 802 communicatively couples together various circuits including one or more processors (represented generally by the processor 804) , a memory 805, and computer-readable media (represented generally by the computer-readable medium 806) . The bus 802 may also link various other circuits such as timing sources, peripherals, voltage regulators, and power management circuits, which are well known in the art, and therefore, will not be described any further. A bus interface 808 provides an interface between the bus 802 and a baseband component 304. The baseband component 304 provides various baseband functions to the test apparatus. The bus interface 808 further provides an interface between the bus 802 and an RF component 306. The RF component 306 provides various RF functions to the test apparatus. The RF component is coupled to a plurality of test antenna probes 810. The test antenna probes 810 may include any suitable configuration for any suitable number of antennas, and provide a communication interface or means for communicating with a DUT over a transmission medium. Depending upon the nature of the test apparatus, a user interface 812 (e.g., keypad, display, speaker, microphone, joystick) may also be provided.

The processor 804 is responsible for managing the bus 802 and general processing, including the execution of software stored on the computer-readable medium 806. The software, when executed by the processor 804, causes the processing system 814 to perform the various functions described below for any particular apparatus. The processor 804 may also use the computer-readable medium 806 and the memory 805 for storing data that the processor 804 manipulates when executing software.

In some aspects of the disclosure, the processor 804 may include UE configuration circuitry 840 configured (e.g., in coordination with the memory 805) for various functions, including, e.g., triggering a UE/DUT to report one or more signal quality measurements or parameters, including but not limited to RSRP, RSRPB, and RSARP; configuring TCI states at the UE/DUT, etc. In various examples, the UE configuration circuit 840 may send OTA wireless signals to the UE/DUT to provide suitable configuration. In other examples, the UE configuration circuit 840 may be coupled to a wired interface (not illustrated) for sending signals over a suitable cable or wire to the UE/DUT. For example, the UE configuration circuitry 840 may be configured to implement one or more of the functions described above in relation to FIG. 6, including, e.g., blocks 604, 606, and/or 612. The UE configuration circuitry may further be configured to implement one or more of the functions described above in relation to FIG. 7, including, e.g., blocks 702, 704, 706, and/or 708.

The processor 804 may further include UE communication circuitry 842 configured (e.g., in coordination with the memory 805) for various functions, including, e.g., transmitting a downlink data stream or flow to the UE/DUT, controlling the power of a downlink transmission (e.g., sweeping the power) , receiving feedback relating to the downlink data stream, and determining a throughput of the UE/DUT. For example, the UE communication circuitry 842 may be configured to implement one or more of the functions described above in relation to FIG. 6, including, e.g., blocks 604 and/or 606.

The processor 804 may further include AoA determination circuitry 844 configured (e.g., in coordination with the memory 805) for various functions, including, e.g., configuring the test antenna probes 810 to transmit to the UE/DUT from a given grid point in a suitable (e.g., spherical) grid; determining the EIS at which the throughput exceeds a given threshold; calculating an average EIS based on the measured EIS for each of a plurality of polarizations; and identifying a beam peak direction based on the determined AoA where the minimum averaged EIS is found. In another example, the AoA determination circuitry 844 may be configured (e.g., in coordination with the memory 805) for functions including, e.g., sorting the grid points based on RSRPB measurements, and selecting a set of top grid points based on the highest RSRPB measured values. For example, the AoA determination circuitry 844 may be configured to implement one or more of the functions described above in relation to FIG. 6, including, e.g., blocks 604 and/or 606.

The processor 804 may further include channel equalizing circuitry 846 configured (e.g., in coordination with the memory 805) for various functions, including, e.g., equalizing a channel matrix of an OTA channel of a test chamber based on cross-interference between beams with different AoAs. In some examples, equalizing the channel matrix may include operating in coordination with the UE configuration circuitry 840 and/or the UE communication circuitry 842 to configure the UE/DUT with a TCI state corresponding to a given beam, and to trigger the UE/DUT to report a signal quality of a beam (e.g., RSRPB and/or RSARP) . In further examples, the channel equalizing circuitry 846 may be configured for constructing an inverse of a measured channel matrix to reduce or remove the impact of the test chamber OTA channel. For example, the channel equalizing circuitry 846 may be configured to implement one or more of the functions described above in relation to FIG. 6, including, e.g., block 612. The channel equalizing circuitry 846 may further be configured to implement one or more of the functions described above in relation to FIG. 7.

The processor 804 may further include isolation determination circuitry 848 configured (e.g., in coordination with the memory 805) for various functions, including, e.g., determining whether the isolation between two polarizations within one beam is greater than a first minimum threshold isolation, determining whether the isolation between two beams (i.e., the isolation between any polarization from the two beams) is greater than a second minimum threshold isolation. For example, the isolation determination circuitry 848 may be configured to implement one or more of the functions described above in relation to FIG. 6, including, e.g., blocks 608 and/or 614.

The processor 804 may further include reference sensitivity (REFSENS) determination circuitry 849 configured (e.g., in coordination with the memory 805) for various functions, including, e.g., determining the EIS level at which the downlink throughput meets or exceeds the requirements for the specified reference measurement channel. For example, the REFSENS determination circuitry 849 may be configured to implement one or more of the functions described above in relation to FIG. 6, including, e.g., block 610.

One or more processors 804 in the processing system may execute software. Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise. The software may reside on a computer-readable medium 806. The computer-readable medium 806 may be a non-transitory computer-readable medium. A non-transitory computer-readable medium includes, by way of example, a magnetic storage device (e.g., hard disk, floppy disk, magnetic strip) , an optical disk (e.g., a compact disc (CD) or a digital versatile disc (DVD) ) , a smart card, a flash memory device (e.g., a card, a stick, or a key drive) , a random access memory (RAM) , a read only memory (ROM) , a programmable ROM (PROM) , an erasable PROM (EPROM) , an electrically erasable PROM (EEPROM) , a register, a removable disk, and any other suitable medium for storing software and/or instructions that may be accessed and read by a computer. The computer-readable medium 806 may reside in the processing system 814, external to the processing system 814, or distributed across multiple entities including the processing system 814. The computer-readable medium 806 may be embodied in a computer program product. By way of example, a computer program product may include a computer-readable medium in packaging materials. Those skilled in the art will recognize how best to implement the described functionality presented throughout this disclosure depending on the particular application and the overall design constraints imposed on the overall system.

In one or more examples, the computer-readable storage medium 806 may store computer-executable code that includes UE configuration instructions 860 that configure a test apparatus 800 for various functions, including, e.g., triggering a UE/DUT to report one or more signal quality measurements or parameters, including but not limited to RSRP, RSRPB, and RSARP; configuring TCI states at the UE/DUT, etc. In various examples, the UE configuration instructions 860 may cause the test antenna probes 810 to send OTA wireless signals to the UE/DUT to provide suitable configuration. In other examples, the UE configuration instructions 840 may cause a wired interface (not illustrated) to send signals over a suitable cable or wire to the UE/DUT. For example, the UE configuration instructions 860 may be configured to cause a test apparatus 800 to implement one or more of the functions described above in relation to FIG. 6, including, e.g., blocks 604, 606, and/or 612. The UE configuration instructions 860 may further be configured to implement one or more of the functions described above in relation to FIG. 7, including, e.g., blocks 702, 704, 706, and/or 708.

The computer-readable storage medium 806 may further store computer-executable code that includes UE communication instructions 862 that configure a test apparatus 800 for various functions, including, e.g., causing a test antenna probe 810 to transmit a downlink data stream or flow to the UE/DUT, controlling the power of a downlink transmission (e.g., sweeping the power) , receiving feedback relating to the downlink data stream, and determining a throughput of the UE/DUT. For example, the UE communication instructions 862 may be configured to implement one or more of the functions described above in relation to FIG. 6, including, e.g., blocks 604 and/or 606.

The computer-readable storage medium 806 may further store computer-executable code that includes AoA determination instructions 864 that configure a test apparatus 800 for various functions, including, e.g., configuring the test antenna probes 810 to transmit to the UE/DUT from a given grid point in a suitable (e.g., spherical) grid; determining the EIS at which the throughput exceeds a given threshold; calculating an average EIS based on the measured EIS for each of a plurality of polarizations; and identifying a beam peak direction based on the determined AoA where the minimum averaged EIS is found. In another example, the AoA determination instructions 864 may configure a test apparatus 800 for functions including, e.g., sorting the grid points based on RSRPB measurements, and selecting a set of top grid points based on the highest RSRPB measured values. For example, the AoA determination instructions 844 may be configured to implement one or more of the functions described above in relation to FIG. 6, including, e.g., blocks 604 and/or 606.

The computer-readable storage medium 806 may further store computer-executable code that includes channel equalizing instructions 866 that configure a test apparatus 800 for various functions, including, e.g., equalizing a channel matrix of an OTA channel of a test chamber based on cross-interference between beams with different AoAs. In some examples, equalizing the channel matrix may include operating in coordination with the UE configuration instructions 860 and/or the UE communication instructions 862 to configure the UE/DUT with a TCI state corresponding to a given beam, and to trigger the UE/DUT to report a signal quality of a beam (e.g., RSRPB and/or RSARP) . In further examples, the channel equalizing instructions 866 may be configured for constructing an inverse of a measured channel matrix to reduce or remove the impact of the test chamber OTA channel. For example, the channel equalizing instructions 866 may be configured to implement one or more of the functions described above in relation to FIG. 6, including, e.g., block 612. The channel equalizing instructions 866 may further be configured to implement one or more of the functions described above in relation to FIG. 7.

The computer-readable storage medium 806 may further store computer-executable code that includes isolation determination instructions 868 that configure a test apparatus 800 for various functions, including, e.g., determining whether the isolation between two polarizations within one beam is greater than a first minimum threshold isolation, determining whether the isolation between two beams (i.e., the isolation between any polarization from the two beams) is greater than a second minimum threshold isolation. For example, the isolation determination instructions 868 may be configured to implement one or more of the functions described above in relation to FIG. 6, including, e.g., blocks 608 and/or 614.

computer-readable storage medium 806 may further store computer-executable code that includes reference sensitivity (REFSENS) determination instructions 869 that configure a test apparatus 800 for various functions, including, e.g., determining the EIS level at which the downlink throughput meets or exceeds the requirements for the specified reference measurement channel. For example, the REFSENS determination instructions 869 may be configured to implement one or more of the functions described above in relation to FIG. 6, including, e.g., block 610.

In one configuration, a test apparatus 800 includes means for determining a plurality of AoAs, means for determining isolation across polarizations and across beams, means for testing UE/DUT throughput, and means for equalizing an OTA channel. In one aspect, the aforementioned means may be the processor (s) 804 shown in FIG. 8 configured to perform the functions recited by the aforementioned means. In another aspect, the aforementioned means may be a circuit or any apparatus configured to perform the functions recited by the aforementioned means.

Of course, in the above examples, the circuitry included in the processor 804 is merely provided as an example, and other means for carrying out the described functions may be included within various aspects of the present disclosure, including but not limited to the instructions stored in the computer-readable storage medium 806, or any other suitable apparatus or means described in any one of the FIGs. 2, 3, and/or 5, and utilizing, for example, the processes and/or algorithms described herein in relation to FIGs. 6 and/or 7.

Further Examples Having a Variety of Features:

Example 1: A method, apparatus, and non-transitory computer-readable medium for testing a device under test (DUT) positioned in a test chamber, comprising: determining a first over-the-air (OTA) angle of arrival (AoA) for a first beam directed from the first antenna probe to the DUT, based on a first signal quality measurement of the first beam; while fixing the first OTA AoA, determining a second OTA AoA for a second beam directed from the second antenna probe to the DUT, based on a second signal quality measurement of the second beam; and equalizing a channel matrix of an OTA channel of the test chamber based on cross-interference between the first beam and the second beam, and based on cross-interference between a plurality of polarizations within each of the first beam and the second beam.

Example 2: A method, apparatus, and non-transitory computer-readable medium of Example 1, wherein determining the first OTA AoA comprises: selecting a first beam direction having a highest effective isotropic sensitivity (EIS) from among a first plurality of beam directions, and wherein determining the second OTA AoA comprises: while fixing the first OTA AoA, selecting a second beam direction having a highest EIS from among a second plurality of beam directions.

Example 3: A method, apparatus, and non-transitory computer-readable medium of any of Examples 1 to 2, wherein determining the first OTA AoA comprises selecting a first set of beam directions having a highest reference signal received power (RSRP) or reference signal received power per branch (RSRPB) from among a first plurality of beam directions, and wherein determining the second OTA AoA comprises: while fixing the first OTA AoA, for each beam direction of the first set of beam directions, select a second set of beam directions having a highest RSRP or RSRPB from among a second plurality of beam directions, and further comprising selecting the first OTA AoA and the second OTA AoA from among the first set of beam directions and the second set of beam directions based on the highest combined RSRP.

Example 4: A method, apparatus, and non-transitory computer-readable medium of any of Examples 1 to 3, further comprising determining that the selected first OTA AoA and the second OTA AoA pass a reference sensitivity power level (REFSENS) test.

Example 5: A method, apparatus, and non-transitory computer-readable medium of any of Examples 1 to 4, further comprising determining that an isolation between the first beam and the second beam is greater than a threshold isolation.

Example 6: A method, apparatus, and non-transitory computer-readable medium of any of Examples 1 to 5, wherein the equalizing the channel matrix comprises triggering the DUT to report a first reference signal received power per branch (RSRPB) and reference signal antenna relative phase (RSARP) of the first beam between a plurality of polarizations while configured for receiving the first beam; triggering the DUT to report a second RSRPB and RSARP of the second beam between a plurality of polarizations while configured for receiving the first beam; triggering the DUT to report a third RSRPB and RSARP of the first beam between a plurality of polarizations while configured for receiving the second beam; triggering the DUT to report a fourth RSRPB and RSARP of the second beam between a plurality of polarizations while configured for receiving the second beam; and constructing an inverse of the channel matrix based on the first RSRPB and RSARP, the second RSRPB and RSARP, the third RSRPB and RSARP, and the fourth RSRPB and RSARP.

Example 7: A method, apparatus, and non-transitory computer-readable medium of any of Examples 1 to 6, wherein the first beam and the second beam are triggered by multiple transmission configuration indicators (TCIs) , and wherein the first beam and the second beam are: transmitted simultaneously, or transmitted sequentially.

Example 8: A method, apparatus, and non-transitory computer-readable medium of any of Examples 1 to 7, wherein the first RSRPB and RSARP, the second RSRPB and RSARP, the third RSRPB and RSARP, and the fourth RSRPB and RSARP are each based on respective synchronization signals (SS) or channel state information reference signals (CSI-RS) .

The detailed description set forth above in connection with the appended drawings is intended as a description of various configurations and is not intended to represent the only configurations in which the concepts described herein may be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of various concepts. However, those skilled in the art will readily recognize that these concepts may be practiced without these specific details. In some instances, this description provides well known structures and components in block diagram form in order to avoid obscuring such concepts.

While this description describes certain aspects and examples with reference to some illustrations, those skilled in the art will understand that additional implementations and use cases may come about in many different arrangements and scenarios. Innovations described herein may be implemented across many differing platform types, devices, systems, shapes, sizes, packaging arrangements. For example, implementations and/or uses may come about via integrated chip (IC) embodiments and other non-module-component based devices (e.g., end-user devices, vehicles, communication devices, computing devices, industrial equipment, retail/purchasing devices, medical devices, artificial intelligence (AI) -enabled devices, etc. ) . While some examples may or may not be specifically directed to use cases or applications, a wide assortment of applicability of described innovations may occur. Implementations may span over a spectrum from chip-level or modular components to non-modular, non-chip-level implementations and further to aggregate, distributed, or original equipment manufacturer (OEM) devices or systems incorporating one or more aspects of the disclosed technology. In some practical settings, devices incorporating described aspects and features may also necessarily include additional components and features for implementation and practice of claimed and described embodiments. For example, transmission and reception of wireless signals includes a number of components for analog and digital purposes (e.g., hardware components including antenna, radio frequency (RF) chains, power amplifiers, modulators, buffer, processor (s) , interleaver, adders/summers, etc. ) . It is intended that the disclosed technology may be practiced in a wide variety of devices, chip-level components, systems, distributed arrangements, end-user devices, etc. of varying sizes, shapes, and constitution.

By way of example, various aspects of this disclosure may be implemented within systems defined by 3GPP, such as fifth-generation New Radio (5G NR) , Long-Term Evolution (LTE) , the Evolved Packet System (EPS) , the Universal Mobile Telecommunication System (UMTS) , and/or the Global System for Mobile (GSM) . Various aspects may also be extended to systems defined by the 3rd Generation Partnership Project 2 (3GPP2) , such as CDMA2000 and/or Evolution-Data Optimized (EV-DO) . Other examples may be implemented within systems employing IEEE 802.11 (Wi-Fi) , IEEE 802.16 (WiMAX) , IEEE 802.20, Ultra-Wideband (UWB) , Bluetooth, and/or other suitable systems. The actual telecommunication standard, network architecture, and/or communication standard employed will depend on the specific application and the overall design constraints imposed on the system.

The present disclosure uses the word “exemplary” to mean “serving as an example, instance, or illustration. ” Any implementation or aspect described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other aspects of the disclosure. Likewise, the term “aspects” does not require that all aspects of the disclosure include the discussed feature, advantage, or mode of operation. The present disclosure uses the terms “coupled” and/or “communicatively coupled” to refer to a direct or indirect coupling between two objects. For example, if object A physically touches object B, and object B touches object C, then objects A and C may still be considered coupled to one another-even if they do not directly physically touch each other. For instance, a first object may be coupled to a second object even though the first object is never directly physically in contact with the second object. The present disclosure uses the terms “circuit” and “circuitry” broadly, to include both hardware implementations of electrical devices and conductors that, when connected and configured, enable the performance of the functions described in the present disclosure, without limitation as to the type of electronic circuits, as well as software implementations of information and instructions that, when executed by a processor, enable the performance of the functions described in the present disclosure.

One or more of the components, steps, features and/or functions illustrated in FIGs. 1–8 may be rearranged and/or combined into a single component, step, feature, or function or embodied in several components, steps, or functions. Additional elements, components, steps, and/or functions may also be added without departing from novel features disclosed herein. The apparatus, devices, and/or components illustrated in FIGs. 1–8 may be configured to perform one or more of the methods, features, or steps described herein. The novel algorithms described herein may also be efficiently implemented in software and/or embedded in hardware.

It is to be understood that the specific order or hierarchy of steps in the methods disclosed is an illustration of exemplary processes. Based upon design preferences, it is understood that the specific order or hierarchy of steps in the methods may be rearranged. The accompanying method claims present elements of the various steps in a sample order and are not meant to be limited to the specific order or hierarchy presented unless specifically recited therein.

Applicant provides this description to enable any person skilled in the art to practice the various aspects described herein. Those skilled in the art will readily recognize various modifications to these aspects and may apply the generic principles defined herein to other aspects. Applicant does not intend the claims to be limited to the aspects shown herein, but to be accorded the full scope consistent with the language of the claims, wherein reference to an element in the singular is not intended to mean “one and only one” unless specifically so stated, but rather “one or more. ” Unless specifically stated otherwise, the present disclosure uses the term “some” to refer to one or more. A phrase referring to “at least one of” a list of items refers to any combination of those items, including single members. As an example, “at least one of: a, b, or c” is intended to cover: a; b; c; a and b; a and c; b and c; and a, b and c. All structural and functional equivalents to the elements of the various aspects described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims.

Claims

A test apparatus for testing a device under test (DUT) positioned in a test chamber, the test apparatus comprising:

a processor;

a memory coupled to the processor;

a first test antenna probe coupled to the processor; and

a second test antenna probe coupled to the processor,

wherein the processor is configured to:

determine a first over-the-air (OTA) angle of arrival (AoA) for a first beam directed from the first antenna probe to the DUT, based on a first signal quality measurement of the first beam;

while fixing the first OTA AoA, determine a second OTA AoA for a second beam directed from the second antenna probe to the DUT, based on a second signal quality measurement of the second beam; and

equalize a channel matrix of an OTA channel of the test chamber based on cross-interference between the first beam and the second beam, and based on cross-interference between a plurality of polarizations within each of the first beam and the second beam.
The test apparatus of claim 1,

wherein the processor, being configured to determine the first OTA AoA, is configured to:

select a first beam direction having a highest effective isotropic sensitivity (EIS) from among a first plurality of beam directions, and

wherein the processor, being configured to determine the second OTA AoA, is configured to:

while fixing the first OTA AoA, select a second beam direction having a highest EIS from among a second plurality of beam directions.
The test apparatus of claim 1,

wherein the processor, being configured to determine the first OTA AoA, is configured to select a first set of beam directions having a highest reference signal received power (RSRP) or reference signal received power per branch (RSRPB) from among a first plurality of beam directions, and

wherein the processor, being configured to determine the second OTA AoA, is configured to: while fixing the first OTA AoA, for each beam direction of the first set of beam directions, select a second set of beam directions having a highest RSRP or RSRPB from among a second plurality of beam directions, and

wherein the processor is further configured to select the first OTA AoA and the second OTA AoA from among the first set of beam directions and the second set of beam directions based on the highest combined RSRP.
The test apparatus of claim 3, wherein the processor is further configured to:

determine that the selected first OTA AoA and the second OTA AoA pass a reference sensitivity power level (REFSENS) test.
The test apparatus of claim 3, wherein the processor is further configured to:

determine that an isolation between the first beam and the second beam is greater than a threshold isolation.
The test apparatus of claim 1, wherein the processor, being configured to equalize the channel matrix, is further configured to:

trigger the DUT to report a first reference signal received power per branch (RSRPB) and reference signal antenna relative phase (RSARP) of the first beam between a plurality of polarizations while configured for receiving the first beam;

trigger the DUT to report a second RSRPB and RSARP of the second beam between a plurality of polarizations while configured for receiving the first beam;

trigger the DUT to report a third RSRPB and RSARP of the first beam between a plurality of polarizations while configured for receiving the second beam;

trigger the DUT to report a fourth RSRPB and RSARP of the second beam between a plurality of polarizations while configured for receiving the second beam; and

construct an inverse of the channel matrix based on the first RSRPB and RSARP, the second RSRPB and RSARP, the third RSRPB and RSARP, and the fourth RSRPB and RSARP.
The test apparatus of claim 6, wherein the first beam and the second beam are triggered by multiple transmission configuration indicators (TCIs) , and wherein the first beam and the second beam are: transmitted simultaneously, or transmitted sequentially.
The test apparatus of claim 6, wherein the first RSRPB and RSARP, the second RSRPB and RSARP, the third RSRPB and RSARP, and the fourth RSRPB and RSARP are each based on respective synchronization signals (SS) or channel state information reference signals (CSI-RS) .
A method for testing a device under test (DUT) positioned in a test chamber, the method comprising:

determining a first over-the-air (OTA) angle of arrival (AoA) for a first beam directed to the DUT, based on a first signal quality measurement of the first beam;

while fixing the first OTA AoA, determining a second OTA AoA for a second beam directed to the DUT, based on a second signal quality measurement of the second beam; and

equalizing a channel matrix of an OTA channel of the test chamber based on cross-interference between the first beam and the second beam, and based on cross-interference between a plurality of polarizations within each of the first beam and the second beam.
The method of claim 9,

wherein determining the first OTA AoA comprises:

selecting a first beam direction having a highest effective isotropic sensitivity (EIS) from among a first plurality of beam directions, and

wherein determining the second OTA AoA comprises:

while fixing the first OTA AoA, selecting a second beam direction having a highest EIS from among a second plurality of beam directions.
The method of claim 9,

wherein determining the first OTA AoA comprises selecting a first set of beam directions having a highest reference signal received power (RSRP) or reference signal received power per branch (RSRPB) from among a first plurality of beam directions, and

wherein determining the second OTA AoA comprises: while fixing the first OTA AoA, for each beam direction of the first set of beam directions, selecting a second set of beam directions having a highest RSRP or RSRPB from among a second plurality of beam directions,

the method further comprising selecting the first OTA AoA and the second OTA AoA from among the first set of beam directions and the second set of beam directions based on the highest combined RSRP.
The method of claim 11, further comprising:

determining that the selected first OTA AoA and the second OTA AoA pass a reference sensitivity power level (REFSENS) test.
The method of claim 11, further comprising:

determining that an isolation between the first beam and the second beam is greater than a threshold isolation.
The method of claim 9, wherein the equalizing the channel matrix comprises:

triggering the DUT to report a first reference signal received power per branch (RSRPB) and reference signal antenna relative phase (RSARP) of the first beam between a plurality of polarizations while configured for receiving the first beam;

triggering the DUT to report a second RSRPB and RSARP of the second beam between a plurality of polarizations while configured for receiving the first beam;

triggering the DUT to report a third RSRPB and RSARP of the first beam between a plurality of polarizations while configured for receiving the second beam;

triggering the DUT to report a fourth RSRPB and RSARP of the second beam between a plurality of polarizations while configured for receiving the second beam; and

constructing an inverse of the channel matrix based on the first RSRPB and RSARP, the second RSRPB and RSARP, the third RSRPB and RSARP, and the fourth RSRPB and RSARP.
The method of claim 14, wherein the first beam and the second beam are triggered by multiple transmission configuration indicators (TCIs) , and wherein the first beam and the second beam are: transmitted simultaneously, or transmitted in sequence.
The method of claim 14, wherein the first RSRPB and RSARP, the second RSRPB and RSARP, the third RSRPB and RSARP, and the fourth RSRPB and RSARP are each based on respective synchronization signals (SS) or channel state information reference signals (CSI-RS) .
A test apparatus for testing a device under test (DUT) positioned in a test chamber, the test apparatus comprising:

means for determining a first over-the-air (OTA) angle of arrival (AoA) for a first beam directed to the DUT, based on a first signal quality measurement of the first beam;

means for, while fixing the first OTA AoA, determining a second OTA AoA for a second beam directed to the DUT, based on a second signal quality measurement of the second beam; and

means for equalizing a channel matrix of an OTA channel of the test chamber based on cross-interference between the first beam and the second beam, and based on cross-interference between a plurality of polarizations within each of the first beam and the second beam.
The test apparatus of claim 17,

wherein the means for determining the first OTA AoA comprises:

means for selecting a first beam direction having a highest effective isotropic sensitivity (EIS) from among a first plurality of beam directions, and

wherein the means for determining the second OTA AoA comprises:

means for, while fixing the first OTA AoA, selecting a second beam direction having a highest EIS from among a second plurality of beam directions.
The test apparatus of claim 17,

wherein the means for determining the first OTA AoA comprises means for selecting a first set of beam directions having a highest reference signal received power (RSRP) or reference signal received power per branch (RSRPB) from among a first plurality of beam directions, and

wherein the means for determining the second OTA AoA comprises: means for, while fixing the first OTA AoA, for each beam direction of the first set of beam directions, selecting a second set of beam directions having a highest RSRP or RSRPB from among a second plurality of beam directions,

the test apparatus further comprising means for selecting the first OTA AoA and the second OTA AoA from among the first set of beam directions and the second set of beam directions based on the highest combined RSRP.
The test apparatus of claim 19, further comprising:

means for determining that the selected first OTA AoA and the second OTA AoA pass a reference sensitivity power level (REFSENS) test.
The test apparatus of claim 19, further comprising:

means for determining that an isolation between the first beam and the second beam is greater than a threshold isolation.
The test apparatus of claim 17, wherein the means for equalizing the channel matrix comprises:

means for triggering the DUT to report a first reference signal received power per branch (RSRPB) and reference signal antenna relative phase (RSARP) of the first beam between a plurality of polarizations while configured for receiving the first beam;

means for triggering the DUT to report a second RSRPB and RSARP of the second beam between a plurality of polarizations while configured for receiving the first beam;

means for triggering the DUT to report a third RSRPB and RSARP of the first beam between a plurality of polarizations while configured for receiving the second beam;

means for triggering the DUT to report a fourth RSRPB and RSARP of the second beam between a plurality of polarizations while configured for receiving the second beam; and

means for constructing an inverse of the channel matrix based on the first RSRPB and RSARP, the second RSRPB and RSARP, the third RSRPB and RSARP, and the fourth RSRPB and RSARP.
The test apparatus of claim 22, wherein the first beam and the second beam are triggered by multiple transmission configuration indicators (TCIs) , and wherein the first beam and the second beam are: transmitted simultaneously, or transmitted in sequence.
The test apparatus of claim 22, wherein the first RSRPB and RSARP, the second RSRPB and RSARP, the third RSRPB and RSARP, and the fourth RSRPB and RSARP are each based on respective synchronization signals (SS) or channel state information reference signals (CSI-RS) .
A non-transitory computer-readable medium storing computer-executable code, comprising instructions for causing a test apparatus for testing a device under test (DUT) positioned in a test chamber, to:

determine a first over-the-air (OTA) angle of arrival (AoA) for a first beam directed from the first antenna probe to the DUT, based on a first signal quality measurement of the first beam;

while fixing the first OTA AoA, determine a second OTA AoA for a second beam directed from the second antenna probe to the DUT, based on a second signal quality measurement of the second beam; and

equalize a channel matrix of an OTA channel of the test chamber based on cross-interference between the first beam and the second beam, and based on cross-interference between a plurality of polarizations within each of the first beam and the second beam.
The non-transitory computer-readable medium of claim 25,

wherein the instructions for causing the test apparatus to determine the first OTA AoA, comprise instructions for causing the test apparatus to:

select a first beam direction having a highest effective isotropic sensitivity (EIS) from among a first plurality of beam directions, and

wherein the instructions for causing the test apparatus to determine the second OTA AoA, comprise instructions for causing the test apparatus to:

while fixing the first OTA AoA, select a second beam direction having a highest EIS from among a second plurality of beam directions.
The test apparatus of claim 25,

wherein the instructions for causing the test apparatus to determine the first OTA AoA, comprise instructions for causing the test apparatus to select a first set of beam directions having a highest reference signal received power (RSRP) or reference signal received power per branch (RSRPB) from among a first plurality of beam directions, and

wherein the instructions for causing the test apparatus to determine the second OTA AoA, comprise instructions for causing the test apparatus to: while fixing the first OTA AoA, for each beam direction of the first set of beam directions, select a second set of beam directions having a highest RSRP or RSRPB from among a second plurality of beam directions, and

wherein the computer-executable code further comprises instructions for causing the test apparatus to select the first OTA AoA and the second OTA AoA from among the first set of beam directions and the second set of beam directions based on the highest combined RSRP.
The non-transitory computer-readable medium of claim 27, wherein the computer-executable code further comprises instructions for causing the test apparatus to:

determine that the selected first OTA AoA and the second OTA AoA pass a reference sensitivity power level (REFSENS) test.
The non-transitory computer-readable medium of claim 25, wherein the instructions for causing the test apparatus to equalize the channel matrix, comprise instructions for causing the test apparatus to:

trigger the DUT to report a first reference signal received power per branch (RSRPB) and reference signal antenna relative phase (RSARP) of the first beam between a plurality of polarizations while configured for receiving the first beam;

trigger the DUT to report a second RSRPB and RSARP of the second beam between a plurality of polarizations while configured for receiving the first beam;

trigger the DUT to report a third RSRPB and RSARP of the first beam between a plurality of polarizations while configured for receiving the second beam;

trigger the DUT to report a fourth RSRPB and RSARP of the second beam between a plurality of polarizations while configured for receiving the second beam; and

construct an inverse of the channel matrix based on the first RSRPB and RSARP, the second RSRPB and RSARP, the third RSRPB and RSARP, and the fourth RSRPB and RSARP.
The non-transitory computer-readable medium of claim 29, wherein the first RSRPB and RSARP, the second RSRPB and RSARP, the third RSRPB and RSARP, and the fourth RSRPB and RSARP are each based on respective synchronization signals (SS) or channel state information reference signals (CSI-RS) .