ULTRA WIDEBAND TEST SYSTEM

Abstract

A test system comprises a radio frequency (RF) shielded container for housing a UWB receiving device under test; an RF antenna accommodated within the RF shielded container; and a UWB transmitting device operatively coupled to the RF antenna. The UWB transmitting device is configured to transmit a UWB signal within the RF shielded container using the antenna, wherein the transmitted UWB signal is representative of multipath components (MPCs) of signals resulting in an end-use environment from the UWB receiving device transmitting a UWB range signal in the end-use environment.

Description

This application claims priority to the United States provisional application serial number 63 / 023,972, filed on May 13, 2020, the disclosure of which is incorporated herein in its entirety by reference. Technical field of the invention The modalities illustrated and described in this document generally refer to access control system architectures that include ultra-wideband enabled devices, and in particular to systems and methods for testing ultra-wideband enabled devices. Background of the invention Ultra-wideband (UWB) is a radio frequency (RF) technique that uses short, low-power pulses across a broad frequency spectrum. The pulses are on the order of millions of pulses per second. The width of the frequency spectrum is typically greater than 500 megahertz or greater than twenty percent of an arithmetic center frequency. Brief description of the drawings Figure 1 is an illustration of a basic physical access control system (PACS) structure. Figure 2 is a block diagram of an example of an ultra-wideband (UWB) capable device and a smart UWB device that includes angle-of-arrival capability. Figure 3 is a block diagram illustrating portions of an example of a continuous UWB PACS. Figures 4A and 4B are examples of radio packets that can be sent during a range operation. Figure 5 is an illustration of an example of a deconvolution operation of a scoped procedure by means of a continuous PACS. Figure 6 is a diagram of a test system for a continuous PACS device. Figure 7 graphically illustrates a simulation approach to determine a UWB test signal. Figure 8 shows waveforms associated with the development of a UWB test signal using simulation. Figure 9 is a flowchart of a continuous PACS operating method. Figure 10 is a schematic block diagram of portions of an example of a UWB-capable device. Detailed description of the invention UWB is a radio communication methodology that utilizes a wide signal bandwidth. Wide bandwidth is typically defined as either a bandwidth greater than 20% of the signal's center frequency (-10 decibels / dB) or a bandwidth greater than 500 megahertz (500 MHz) in absolute terms. Commercial UWB systems are intended for use in complex environments, such as residential, office, or industrial indoor areas. As an example, UWB radio communications can be used in a physical access control system (PACS). A PACS authenticates and authorizes a person to pass through a physical access point, such as a secured door. The architecture of a PACS can vary significantly depending on the application (e.g., a hotel, a residence, an office, etc.), the technology (e.g., access interface technology, door type, etc.), and the manufacturer. Figure 1 illustrates a basic PACS structure useful for an office application. The Access Credential is a data object, a piece of knowledge (e.g., PIN, password, etc.), or a facet of a person's physical being (e.g., face, fingerprint, etc.) that provides proof of the person's identity. The credential device 104 stores the access credential when the access credential is a data object. The credential device 104 can be a smart card or a smartphone.Other examples of credential devices include, but are not limited to, proximity radio frequency identifier (RFID-based) cards, access control cards, credit cards, debit cards, passports, ID cards, remote key fobs, near field communication (NFC) enabled devices, mobile phones, personal digital assistants (PDAs), tags, or any other device configurable to emulate a virtual credential. The credential device 104 can be referred to as the access credential. The reader device 102 retrieves and authenticates the access credential when a credential device is used and sends the access credential to the access controller 106. The access controller 106 compares the access credential to an access control list and grants or denies access based on the comparison, such as controlling an automatic door lock, for example. The functionality of an access controller (106) can be integrated into a reader (102). These reader devices are sometimes referred to as offline readers or standalone readers. If the unlocking mechanism is also included, the device is known as a smart door lock, which is most commonly used in residential applications. Devices such as smart door locks are often battery-powered, and power consumption and battery life can be key parameters for these devices. In a PACS, an access sequence consists of four parts: Proof of Presence, Intent Detection, Authentication, and Authorization. The user approaches the door and presents their access credential or credential device. This provides the Proof of Presence and Intent portions of the sequence. The reader device verifies the validity of the access credential (the Authentication portion) and sends it to the access controller (for example, using a local area network, or LAN), which grants or denies access (the Authorization portion). Seamless access control refers to granting physical access to an authorized user through a controlled portal without requiring intrusive user actions, such as inserting or swiping an access card into a card reader or entering a personal identification number (PIN) or password. Radio Pulse Wideband (IR-UWB, or simply UWB) can provide Proof of Presence information securely. The large bandwidth of UWB systems provides a high level of resilience to frequency-selective fading, an effect that can limit the performance of narrowband technologies. UWB's secure and accurate range capability makes it a suitable technology for enabling seamless access, as range can be used to determine Presence and Intent without requiring any action from the user. Figure 2 is a block diagram of an example of a UWB-capable device (e.g., a reader or reader / controller device) and a smart UWB-capable device (e.g., a smartphone credential device). The range of the UWB-capable devices can be used to determine user intent. Intent can be inferred from the change in distance between the UWB-capable device and the smart UWB-capable device, and from the change in angle between the UWB-capable device and the smart UWB-capable device. The UWB-capable device can perform rangefinding using two-way time-of-flight (TOF) rangefinding. In TWR, radio packets are exchanged between the UWB-capable device (e.g., the reader device) and the smart UWB-capable device (e.g., a UWB-capable smartphone). The timing differences for transmitting and receiving the packets between the reader device and the smartphone can be used to calculate range information, such as changes in one or both of the distance and angle, to determine intent. Figure 3 is a block diagram illustrating portions of an example of a continuous UWB PACS. The transmitting device 304 can be a user's smart UWB-capable device, and the receiving device 302 can be a UWB reader device. The transmitting device 304 transmits a UWB signal 312, and the receiving device 302 receives a UWB signal 314. The transmitted signal can be sent as part of a range operation. However, as noted earlier in this document, the environment for a UWB system can be complex. In these environments, signal reflection and diffraction play a very important role. The received UWB signal 314 may be the sum of attenuated, delayed, and possibly overlapping versions of the transmitted signal, and the received UWB signal may vary over time (due to receiver / transmitter movement or environmental changes). These different versions of the transmitted signal detected by the receiving device 302 can be called multipath components (MPCs). For continuous PACS range operations, it is important to identify the first path and determine the time of arrival (TOA) because it is the most representative of the distance between the transmitting device 304 and the receiving device 302. However, the strength of the first path component can depend on the environment. The received UWB signal 314 shows a first path component 318 with the largest amplitude and a first path component 320 with a smaller amplitude than the other components. The smaller amplitude can occur in the obstructed line-of-sight (LOS) scenario shown in Figure 3, where there is no direct path between the transmitting device 304 and the receiving device 302. To accurately detect the LOS TOA, the receiver's dynamic range is enhanced using correlation. In correlation operations, the channel impulse response (CIR) is determined or estimated by a correlator in the receiver device 302. The correlator performs deconvolution into a known pulse pattern associated with a radio packet of the incoming UWB signal. The symbols in the known pulse pattern have perfect periodic autocorrelation properties, allowing the CIR to be determined by direct correlation. Figures 4A and 4B are examples of radio packets that can be sent during a range operation. In Figure 4A, radio packet 420 includes a synchronization (SYNC) field and a start-of-frame delimiter (SFD) field. The SYNC field can include a repeated Ipatov sequence to provide the desired autocorrelation properties, and the SFD field can include an encrypted Ipatov sequence. Radio packet 420 also includes a physical layer (PHY) header (PHR) and a PHY service data unit (PSDU). In Figure 4B, the 422 radio packet includes the SYNC field and the SFD field as in Figure 4A, but it also includes an encrypted timestamp sequence (STS) field. Using an STS field provides an additional level of security because the STS field is unpredictable and does not cause periodicity-related spikes in the transmit signal's frequency spectrum. Figure 5 illustrates an example of deconvolution operation of a range procedure using a continuous PACS. Waveform 510 represents a transmit signal. The pulses in the waveform represent bits within the transmitted radio packets. Waveform 530 represents the theoretical CIR that would be received by a receiving device. The signal from the first path has the highest amplitude and is used to determine the time of flight (TOF) for the range procedure. Waveform 514 represents an actual received signal due to reflections in the continuous PACS environment. Waveform 532 represents the estimated theoretical IRC constructed using deconvolution, and waveform 532 is used by the receiving device to determine information. MA / t / ZUZÓ / UU41Ί U of TOF. One challenge in implementing a UWB system, such as a PACS, is that because the received signal is a sum of the components from multiple reflected and direct paths, the total received signal can be unique to each environment. The circuitry for receiving the signals and the algorithms for deconvolution may need to be optimized for a particular environment. However, it would be desirable for the UWB system to be ready to use without time-consuming installation procedures for system optimization. Figure 6 is a diagram of a 600 test system for a UWB-capable device (e.g., a continuous PACS). The 600 test system includes an RF-shielded enclosure (e.g., a box) to house a UWB receiving device under test. The UWB receiving device can be a UWB reader or a smart UWB-capable device. The 600 test system also includes an RF antenna housed within the RF-shielded enclosure and a UWB transmitting device. The UWB transmitting device is operatively coupled to the RF antenna and configured to transmit a UWB signal within the RF-shielded enclosure using the antenna. The UWB transmitting device may include a UWB physical layer (PHY) that transmits signals in the UWB signal band.Additional layers can be implemented in the processing circuitry of the UWB 640 transmitter device. The RF-shielded container 636 can be approximately half a cubic meter in size and can include RF attenuators to attenuate signals transmitted by the antenna inside the container. As explained earlier in this document, a UWB range signal transmitted in an end-use environment will result in attenuated, delayed, time-varying, and possibly overlapping versions of the UWB range signal transmitted in the environment. The signal received by a UWB receiving device in the environment will include MPCs due to the various paths that reflected signals can take in the environment. Using the antenna, the UWB 640 transmitting device transmits a UWB signal within the RF-shielded enclosure that is representative of the MPCs that occur as a result of transmitting a UWB range signal in the unique end-use environment in which the UWB receiving device will be used. To determine the representative signal, electromagnetic field simulation software can be used. Using the software, the user can configure a model of the end-use environment and then simulate the transmission of one or more range signals within the model environment. The transmitted range signal(s) can include one or more of a specified pulse pattern, a radio packet containing a specified preamble, or a radio packet containing a timestamp sequence encrypted to match the range signals used in the environment. Figure 7 graphically illustrates a simulation approach in which the UWB test signal transmitted by the UWB transmitter is determined by electromagnetic field simulation. The model environment 750 is developed using software and shows the position of the UWB receiver device 758 within the model environment. Simulation 752 simulates the UWB range signal transmitted within the model environment to determine the OIR for environment 754. Figure 7 shows the simulated CIR waveform 756. Figure 8 shows waveforms from the simulation. The top waveform, 805, is the UWB transmission signal. It includes a radio packet preamble but does not show the carrier frequency. The middle waveform, 810, is the CIR determined by the simulation, and the bottom waveform, 815, is the signal to be transmitted by the UWB transmitter in the test system, representing the signal that will be seen by the UWB receiver in the real-world environment. The UWB receiver under test determines range information, such as the range distance for the UWB range signal, while the receiver is in the RF-shielded enclosure. In some examples, the receiver deconvolutes the received UWB signal in the RF-shielded enclosure to estimate the channel impulse response (CIR) of the transmitted UWB signal and calculates time-of-flight (TOF) information. If the receiver is a UWB-capable PACS reader, the reader can calculate the distance or angle according to normal operation, and a test result can be made available on a test port of the reader.If the UWB receiving device under test is a smart UWB-capable device, such as a smartphone, a test app or Test App may have been downloaded onto the smart UWB-capable device to implement the test. Another approach to determining the signal to be transmitted by the UWB transmitter in the test system is a measurement approach. In this approach, the first stage of the test is performed in the actual environment where the UWB receiver will be used. A UWB signal, such as a UWB range signal, can be transmitted into the environment using a first antenna and a UWB transmitter. A second antenna or multiple stages are then used to measure the electromagnetic response in the environment. The measured MPCs resulting from the transmission can be added to the signal to be transmitted by the UWB transmitter in the test system. While this approach is more time-consuming than the simulation approach, the measurement approach results in the generation of a UWB test signal, which can then be stored in memory or otherwise recorded. The test can be run multiple times using the generated UWB test signal. This generated UWB test signal is portable and can be sent to different test systems. This is useful when there are different development areas in different geographical locations. Once the UWB test signal is generated, it can be used by other test units at different development sites for the UWB receiving device. Figure 9 is a flowchart of a 900 method test for a UWB receiver device. The UWB device can be integrated into a continuous PACS. The UWB receiver device can be a UWB-capable device, such as a UWB-capable reader or a reader / control device. In some examples, the UWB receiver device is a smart UWB-capable device, such as a smartphone, for use by someone seeking physical access to a controlled access area. In 905, a UWB signal is transmitted within an RF-shielded enclosure containing the UWB receiver under test. The transmitted signal is representative of the multipath components (MPCs) of the signals resulting in an end-use environment for the UWB receiver, resulting from the transmission of a UWB range signal within that environment. In some instances, the transmitted signal is representative of the MPCs resulting in the end-use environment due to reflections of a UWB range signal that would be transmitted by a separate UWB receiver. The transmitted signal within the RF-shielded enclosure can be determined through simulation or prior measurement. In 910, the UWB receiver in the RF-shielded container determines a range using the signal received within the RF-shielded container. This determines whether the UWB receiver would have any difficulty determining the range when a UWB range signal is transmitted in the end-use environment. The devices, systems, and methods described in this document can provide a repeatable technique for testing UWB-capable devices, leading to faster development of UWB devices even when development occurs in different areas and geographical locations. Examples described pertain to UWB-capable physical access control systems, but the devices, systems, and methods can be used to expedite UWB device development for other UWB system applications. Figure 10 is a schematic block diagram of several exemplary components of a UWB 1000-capable device (e.g., an embedded device) to support the device architectures described and illustrated herein. The 1000 device in Figure 10 could be, for example, a UWB-capable reader device that authenticates credential information regarding authority, status, entitlements, and / or privilege rights for the holder of a UWB-capable credential device. At a basic level, a reader device may include an interface (e.g., one or more antennas and integrated circuit (IC) chip(s)) that allows the reader device to exchange data with another device, such as a credential device or another reader device.An example of a credential device is an RFID smart card that has data stored on it that allows a credential device holder to access a secure area or asset protected by the reader device. With reference again to Figure 10, additional examples of a UWB-capable device 1000 to support the device architecture described and illustrated herein may generally include one or more of a memory 1002, a processor 1004, one or more antennas 1006, a communication port or communication module 1008, a network interface device 1010, a user interface 1012, and a power source 1014 or power supply. Memory 1002 can be used in connection with the execution of program or application instructions by means of processing circuitry, and for the temporary or long-term storage of program instructions or instruction sets 1016 and / or authorization data 1018, such as credential data, credential authorization data, or access control data and instructions, as well as any data, data structure, and / or computer-executable instructions that are needed or desired to support the device architecture described above.For example, memory 1002 may contain executable instructions 1016 that are used by a processor 1004 of the processing circuitry to execute other components of device 1000, to make access determinations based on credential or authorization data 1018, and / or to perform any of the functions or operations described herein, such as the method in Figure 9, for example. Memory 1002 may comprise a computer-readable medium, which may be any medium capable of containing, storing, communicating, or transporting data, program code, or instructions for use by or in connection with device 1000. The computer-readable medium may be, for example, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device.More specific examples of suitable computer-readable media include, but are not limited to, an electrical connection having one or more wires or a tangible storage medium such as a laptop floppy disk, a hard disk, random-access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or Flash memory), dynamic RAM (DRAM), any solid-state storage device, generally a compact disc read-only memory (CD-ROM), or other optical or magnetic storage device. Computer-readable media includes, but should not be confused with, computer-readable storage media, which is proposed to cover all physical, non-transient, or similar forms of computer-readable media. The processor 1004 may correspond to one or more computer processing devices or resources. For example, the processor 1004 may be provided as silicon, as a field-programmable gate array (FPGA), an application-specific integrated circuit (ASIO), any other type of integrated circuit (IC) chip, a collection of IC chips, or the like. More specifically, the processor 1004 may be provided as a microprocessor, central processing unit (CPU), or a plurality of microprocessors or CPUs configured to execute instruction sets stored in internal memory 1020 and / or memory 1002. Antenna 1006 can consist of one or more antennas and can be configured to provide wireless communication between device 1000 and another device. Antenna 1006 can be coupled to one or more physical layers (PHY) 1024 to operate using one or more wireless communication protocols and operating frequencies, including, but not limited to, IEEE 802.15.1, Bluetooth, Bluetooth Low Energy (BLE), Near Field Communication (NFC), ZigBee, GSM, CDMA, Wi-Fi, RF, UWB, and similar protocols. For example, antenna 1006 could include one or more antennas coupled to one or more physical layers 1024 to operate using UWB for in-band activity / communication and Bluetooth (e.g., BLE) for out-of-band (OOB) activity / communication. However, any RFID or personal area network (PAN) technology, such as IEEE 502.15.1. Near field communications (NFC), ZigBee, GSM, CDMA, Wi-Fi, etc., may be used alternatively or additionally for the OOB activity / communication described herein. The 1000 device may additionally include a 1008 communication module and / or a 1010 network interface device. The 1008 communication module can be configured to communicate according to any suitable communication protocol with one or more different systems or devices, whether remote or local to the 1000 device. The 1010 network interface device includes hardware to facilitate communication with other devices over a communication network using any of a number of transfer protocols (e.g., frame relay, Internet Protocol (IP), Transmission Control Protocol (TCP), User Datagram Protocol (UDP), Hypertext Transfer Protocol (HTTP), etc.).Example communication networks might include a local area network (LAN), a wide area network (WAN), a packet data network (e.g., the Internet), mobile phone networks (e.g., cellular networks), simple old telephone (POTS) networks, wireless data networks (e.g., the IEEE 802.11 family of standards known as Wi-Fi, the IEEE 802.16 family of standards known as WiMAX), the IEEE 802.15.4 family of standards, and peer-to-peer (P2P) networks, among others. In some examples, the 1010 network interface device might include an Ethernet port or other physical connector, a Wi-Fi card, a network interface card (NIC), a cellular interface (e.g., antenna, filters, and associated circuitry), or similar components.In some examples, the network interface device 1010 may include a plurality of antennas for wireless communication using at least one of the following techniques: single-input multiple-output (SIMO), multiple-input multiple-output (MIMO), or multiple-input single-output (MISO). In some exemplary embodiments, one or more of the antenna 1006, communication module 1008, and / or network interface device 1010, or subcomponents thereof, may be integrated as a single module or device, function or operate as if they were a single module or device, or may comprise elements shared among them. User Interface 1012 may include one or more input and / or display devices. Examples of suitable user input devices that may be included in User Interface 1012 include, but are not limited to, one or more buttons, a keyboard, a mouse, a touch surface, a stylus, a camera, a microphone, etc. Examples of suitable user output devices that may be included in User Interface 1012 include, but are not limited to, one or more LEDs, an LCD panel, a display screen, a touchscreen, one or more lights, a speaker, etc. It should be noted that User Interface 1012 may also include a combined user input and user output device, such as a touchscreen or similar. The power source 1014 can be any suitable internal power source, such as a battery, capacitive power source, or similar type of charge storage device, etc., and / or can include one or more power conversion circuits suitable for converting external power into suitable power (e.g., converting externally supplied AC power into DC power) for components of device 1000. The 1000 device may also include one or more operable 1022 concatenations or buses for transmitting communications between the device's various hardware components. A 1022 system bus can be any of several commercially available bus structures or bus architectures. The system bus may be capable of providing time-of-flight (TOF) information available to a 1026 test port. Additional disclosure and examples Example 1 includes object matter (such as a test system) comprising a radio frequency (RF) shielded container, the shielded container accommodating a UWB receiving device under test; an RF antenna accommodated within the RF shielded container; and a UWB transmitting device operatively coupled to the RF antenna and configured to transmit a UWB signal within the RF shielded container using the antenna, wherein the transmitted UWB signal is representative of multipath components (MPCs) of resulting signals in an end-use environment of the UWB receiving device resulting from transmitting a UWB range signal in the end-use environment. In Example 2, the subject matter of Example 1 optionally includes a UWB transmitting device configured to transmit a UWB signal representing, in the end-use environment, a UWB range signal that includes a specified pulse pattern. In Example 3, the subject matter of one or both of Examples 1 and 2 optionally includes a UWB transmitting device configured to transmit a UWB signal representing transmitting, in the end-use environment, a UWB range signal that includes a radio packet having a specified preamble. In Example 4, the subject matter of one or both of Examples 1 and 3 optionally includes a UWB transmitting device configured to transmit a UWB signal representing transmitting, in the end-use environment, a UWB range signal that includes a radio packet that includes an encrypted timestamp sequence. In Example 5, the subject matter of one or any combination of Examples 1 to 4 optionally includes a UWB transmitting device configured to transmit a UWB signal generated using electromagnetic field simulation software. In Example 6, the subject matter of one or any combination of Examples 1 to 4 optionally includes a UWB transmitting device configured to transmit a UWB signal that is an aggregate of measured MPCs resulting from transmitting the UWB range signal in the end-use environment. In Example 7, the subject matter of one or any combination of Examples 1 to 6 optionally includes an RF-shielded container that includes one or more RF attenuators. In Example 8, the subject matter of one or any combination of Examples 1 to 7 optionally includes an operable UWB receiving device within the RF shielded container to determine a range distance for the UWB range signal. In Example 9, the subject matter of Example 8 optionally includes a UWB receiving device configured to perform deconvolution of a received UWB signal within the RF-shielded container to estimate a channel impulse response (CIR) of the transmitted UWB signal and determine time-of-flight information using the estimated CIR. Example 10 includes subject matter (such as a method for testing a UWB receiving device of a continuous physical access control system) or may optionally be combined with one or any combination of Examples 1 to 9 to include such subject matter comprising transmitting a UWB signal within an RF-shielded container containing the UWB receiving device, wherein the UWB signal transmitted within the container is representative of multipath components (MPCs) of resulting signals in an end-use environment for the UWB receiving device resulting from transmitting a UWB range signal in the end-use environment; and determining, by means of the UWB receiving device, a range distance for the UWB range signal. In Example 11, the subject matter of Example 10 optionally includes the UWB receiving device that performs deconvolution of a received UWB signal to estimate a channel impulse response (CIR) of the transmitted UWB signal and determine time-of-flight information using the estimated CIR. In Example 12, the subject matter of one or both of Examples 10 and 11 optionally includes transmitting a UWB signal representing transmitting, in the end-use environment, a UWB range signal that includes a specified pulse pattern. In Example 13, the subject matter of one or any combination of Examples 10 to 12 optionally includes transmitting a UWB signal representing transmitting, in the end-use environment, a UWB range signal that includes a radio packet having a specified preamble. In Example 14, the subject matter of one or any combination of Examples 10 to 12 optionally includes transmitting a UWB signal representing transmitting, in the end-use environment, a UWB range signal that includes a radio packet that includes an encrypted timestamp sequence. In Example 15, the subject matter of one or any combination of Examples 10 to 14 optionally includes transmitting a UWB signal generated using electromagnetic field simulation software. In Example 16, the subject matter of one or any combination of Examples 10 to 14 optionally includes transmitting a UWB ranging signal using a first antenna; measuring MPCs of resulting signals that result from transmitting the UWB ranging signal; and adding the MPCs of the resulting signals to the UWB signal transmitted to the RF-shielded container. In Example 17, the subject matter of one or any combination of Examples 10 to 16 optionally includes the UWB receiving device, which is a UWB-capable reading device. Example 18 includes subject matter (or may optionally be combined with one or any combination of Examples 1 to 17 to include such subject matter) such as a computer-readable storage medium that includes instructions that, when executed by processing circuitry of an ultra-wideband (UWB) device test unit, cause the test unit to perform actions comprising transmitting a UWB signal into an RF-shielded enclosure containing the UWB device, wherein the UWB signal transmitted into the enclosure is representative of multipath components (MPCs) of resulting signals in an end-use environment for the UWB device resulting from transmitting a UWB range signal into the end-use environment; and receiving a range signal from the UWB device for the UWB range signal. In Example 19, the subject matter of Example 18 optionally includes instructions that cause the test unit to perform actions that include transmitting a UWB signal that represents transmitting, in the end-use environment, a UWB range signal that includes a specified timing pattern. In Example 20, the subject matter of one or both of Examples 18 and 19 optionally includes instructions that cause the test unit to perform actions that include transmitting a UWB signal that represents transmitting, in the end-use environment, a UWB range signal that includes a radio packet that includes an encrypted timestamp sequence. The preceding Examples may be combined in any permutation or combination. The detailed description above includes references to the accompanying drawings, which form a part of the detailed description. The drawings show, by way of illustration, specific embodiments in which the invention may be practiced. These embodiments are also referred to herein as “examples.” All publications, patents, and patent documents cited herein are incorporated herein by reference in their entirety, as if individually incorporated by reference. In the event of inconsistent uses between this document and those documents so incorporated by reference, the use in the incorporated reference(s) shall be deemed supplementary to that in this document; for irreconcilable inconsistencies, the use in this document shall control. In this document, the terms "one" or "an" are used, as is common in patent documents, to include one or more of the following, irrespective of any other instance or use of "at least one" or "one or more." In this document, the term "or" is used to denote a non-exclusive or, such that "A or B" includes "A but not B," "B but not A," and "A and B," unless otherwise stated. In this document, the terms "including" and "in which" are used as the plain English equivalents of the respective terms "comprising" and "wherein." Also, in the following claims, the terms "including" and "comprising" are open-ended, meaning that a system, device, article, composition, formulation, or process that includes elements in addition to those listed after such term in a claim is still deemed to fall within the scope of that claim.Furthermore, in the following claims, the terms “first”, “second”, and “third”, etc. are used simply as labels, and are not intended to impose numerical requirements on their objects. The foregoing description is intended to be illustrative, not restrictive. For example, the examples described above (or one or more aspects thereof) may be used in combination with each other. Other embodiments may be used, such as those determined by a person skilled in the art after reviewing the foregoing description. The summary is provided to enable the reader to quickly ascertain the nature of the technical disclosure. It is presented with the understanding that it shall not be used to interpret or limit the scope or significance of the claims. In the detailed description above, several features may be grouped together to optimize disclosure. This should not be construed as proposing that a disclosed but unclaimed feature is essential to any claim. Rather, the subject matter may be found in fewer than all the features of a particular disclosed embodiment.Accordingly, the following claims are hereby incorporated into the detailed description, each claim standing alone as a separate embodiment, and it is contemplated that these embodiments may be combined with one another in various combinations or permutations. The scope shall be determined by reference to the appended claims, together with the full scope of equivalents to which such claims are entitled.

Claims

1. A test system, comprising: a radio frequency (RF) shielded container, the shielded container for housing a UWB receiving device under test; an RF antenna accommodated within the RF shielded container; and a UWB transmitting device operatively coupled to the RF antenna and configured to transmit a UWB signal within the RF shielded container using the antenna, wherein the transmitted UWB signal is representative of multipath components (MPCs) of signals resulting in an end-use environment of the UWB receiving device resulting from transmitting a UWB range signal in the end-use environment.

2. The test system according to claim 1, wherein the UWB transmitting device is configured to transmit a UWB signal representing, in the end-use environment, a UWB range signal that includes a specified pulse pattern.

3. The test system according to claim 1, wherein the UWB transmitting device is configured to transmit a UWB signal representing, in the end-use environment, a UWB range signal that includes a radio packet having a specified preamble.

4. The test system according to claim 1, wherein the UWB transmitting device is configured to transmit a UWB signal representing, in the end-use environment, a UWB range signal that includes a radio packet that includes an encrypted timestamp sequence.

5. The test system according to claim 1, wherein the UWB transmitter device is configured to transmit a UWB signal generated using electromagnetic field simulation software.

6. The test system according to claim 1, wherein the UWB transmitting device is configured to transmit a UWB signal that is an aggregate of measured MPCs resulting from transmitting the UWB range signal in the end-use environment.

7. The test system according to claim 1, wherein the RF shielded container includes one or more RF attenuators.

8. The test system according to any of claims 1 to 7, including the UWB receiving device, wherein the UWB receiving device is operable within the RF shielded container to determine a range distance for the UWB ranging signal.

9. The test system according to claim 8, wherein the UWB receiving device is configured to perform deconvolution of a received UWB signal within the RF shielded container to estimate a channel impulse response (CIR) of the transmitted UWB signal and determine time-of-flight information using the estimated CIR.

10. A method for testing an ultra-wideband (UWB) receiver device of a continuous physical access control system, the method comprising: transmitting a UWB signal into an RF-shielded enclosure containing the UWB receiver device, wherein the UWB signal transmitted into the enclosure is representative of multipath component (MPC) signals resulting in an end-use environment for the UWB receiver device resulting from transmitting a UWB range signal into the end-use environment; and determining, by means of the UWB receiver device, a range distance for the UWB range signal.

11. The method according to claim 10, wherein determining the range distance includes the UWB receiving device that performs deconvolution of a received UWB signal to estimate a channel impulse response (CIR) of the transmitted UWB signal and determine time-of-flight information using the estimated CIR.

12. The method according to claim 10, wherein transmitting the UWB signal includes transmitting a UWB signal representing transmitting, in the end-use environment, a UWB range signal that includes a specified pulse pattern.

13. The method according to claim 10, wherein transmitting the UWB signal includes transmitting a UWB signal representing transmitting, in the end-use environment, a UWB range signal that includes a radio packet having a specified preamble.

14. The method according to claim 10, wherein transmitting the UWB signal includes transmitting a UWB signal representing transmitting, in the end-use environment, a UWB range signal that includes a radio packet that includes an encrypted timestamp sequence.

15. The method according to claim 10, wherein transmitting the UWB signal includes transmitting a UWB signal generated using electromagnetic field simulation software.

16. The method according to claim 10, wherein transmitting the UWB signal includes: transmitting a UWB range signal using a first antenna; measuring MPCs of resulting signals from transmitting the UWB range signal; and adding the MPCs of the resulting signals to the UWB signal transmitted to the RF-shielded container.

17. The method according to any of claims 10 to 16, wherein the UWB receiving device is a UWB-capable reading device.

18. A computer-readable storage medium that includes instructions that, when executed by processing circuitry of an ultra-wideband (UWB) device test unit, cause the test unit to perform actions comprising: transmitting a UWB signal into an RF-shielded enclosure containing the UWB device, wherein the UWB signal transmitted into the enclosure is representative of multipath components (MPCs) of signals resulting in an end-use environment for the UWB device resulting from transmitting a UWB range signal into the end-use environment; and receiving a range distance from the UWB device for the UWB range signal.

19. The computer-readable storage medium according to claim 18, further comprising instructions causing the test unit to perform actions including transmitting a UWB signal representing transmitting, in the end-use environment, a UWB range signal including a specified timing pattern.

20. The computer-readable storage medium according to any of claims 18 and 19, further comprising instructions causing the test unit to perform actions including transmitting a UWB signal representing transmitting, in the end-use environment, a UWB range signal comprising a radio packet comprising an encrypted timestamp sequence.

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