WO2025007206A1 - Ultra wideband (uwb) link and device configurations and methods - Google Patents

Abstract

Ultra-Wideband (UWB) wireless devices transmit and receive data as modulated coded impulses over a wide frequency spectrum. This allows for devices with low power consumption to communicate over short distances for multiple applications. Accordingly, techniques, devices, systems, processes and methods that improve the performance of UWB transmitters, UWB receivers and UWB transceivers directly or the performance of UWB links between them are provided which are beneficial to the exploitation and penetration of UWB wireless technology within these applications.

Description

ULTRA WIDEBAND (UWB) LINK AND DEVICE CONFIGURATIONS AND METHODS

CROSS-REFERENCE TO RELATED APPLICATIONS

[001] This patent claims the benefit of priority from U.S. Provisional Patent Application 63/511,953 filed July 5, 2023.

FIELD OF THE INVENTION

[002] This invention relates to ultra-wideband wireless radios and more particularly to configuring methods, processes, devices and systems relating to ultra-wideband transmitters, ultra-wideband receivers and ultra-wideband transceivers for enhanced ultra-wideband wireless links employing same.

BACKGROUND OF THE INVENTION

[003] Ultra-Wideband (UWB) technology is a wireless technology for the transmission of large amounts of digital data as modulated coded impulses over a very wide frequency spectrum with very low power over a short distance. Such pulse based transmission being an alternative to today’s wireless communication standards and systems such as IEEE 802.11 (WiFi), IEEE 802.15 wireless personal area networks (PANs), IEEE 802.16 (WiMAX), Universal Mobile Telecommunications System (UMTS), Global System for Mobile Communications (GSM), General Packet Radio Service (GPRS), and those accessing the Industrial, Scientific and Medical (ISM) bands, and International Mobile Telecommunications -2000 (IMT-2000).

[004] Accordingly, techniques, devices, systems, processes and methods that improve the performance of UWB transmitters, UWB receivers and UWB transceivers directly or the performance of links between them are beneficial to their exploitation and penetration within many applications.

[005] Other aspects and features of the present invention will become apparent to those ordinarily skilled in the art upon review of the following description of specific embodiments of the invention in conjunction with the accompanying figures.

SUMMARY OF THE INVENTION [006] It is an object of the present invention to mitigate limitations within the prior art relating to ultra-wideband wireless radios and more particularly to configuring methods, processes, devices and systems relating to ultra-wideband transmitters, ultra-wideband receivers and ultra-wideband transceivers for enhanced ultra-wideband wireless links employing same.

[007] In accordance with an embodiment of the invention there is provided an antenna comprising: a circuit board; a first microstrip line disposed on one side of a virtual axis of the circuit board on a first surface of the circuit board comprising an embedded open stub at a location along the first microstrip line between a first end of the first microstrip line and a second distal end of the first microstrip and a bent open stub at the location along the first microstrip line; a second microstrip line disposed on another side of the virtual axis of the circuit board on the first surface of the circuit board comprising another embedded open stub at a location along the second microstrip line between a first end of the second microstrip line and a second distal end of the second microstrip and a bent open stub at the location along the second microstrip line; a first ground plane slot disposed within a ground plane on one side of the virtual axis of the circuit board on a second surface of the circuit board distal to the first surface at a predetermined location relative to location along the first microstrip line; and a second ground plane slot disposed within the ground plane on the another side of the virtual axis of the circuit board on the second surface of the circuit board distal to the first surface at another predetermined location relative the location along the second microstrip line.

[008] In accordance with an embodiment of the invention there is provided a method comprising the steps of: establishing a wireless radio to listen to a defined channel; establishing an energy detection threshold; listening with the wireless radio to the defined channel for predefined period of time; determining whether the received energy detected whilst listening to the defined channel for predefined period of time exceeds the energy detection threshold; upon a positive determination the received energy detected whilst listening to the defined channel for predefined period of time exceeds the energy detection threshold executing a process comprising the steps of: determining whether a maximum number of listening retries has been exceed or not; upon a positive determination that the maximum number of listening retries has been exceeded either aborting the method or transmitting a frame of data to be transmitted upon the defined channel; and upon a negative determination that the maximum number of listening retries has been exceeded waiting for a defined wait-time and then returning to the step of listening; and upon a negative determination the received energy detected whilst listening to the defined channel for predefined period of time exceeds the energy detection threshold transmitting the frame of data immediately upon the defined channel.

[009] In accordance with an embodiment of the invention there is provided a method comprising the steps of: waiting by a controller of the wireless radio to receive a defined number of frames from a set of radios comprising at least an active radio and a non-active radio; computing with the controller a normalized received signal strength indication (RS SI) average of the defined number of frames for each radio within the set of radios; determining with the controller if the RS SI average of the non-active radio is greater than the RSSI average of the active radio by a defined margin; upon a negative determination that the RSSI average of the non-active radio is greater than the RSSI average of the active radio by the defined margin the method returns to the step of waiting; and upon a positive determination that the RSSI average of the non-active radio RSSI is greater than the active radio RSSI average of the active radio by the defined margin the controller reconfigures such that the non-active radio becomes the active radio and the previously active radio becomes the non-active radio before returning to the step of waiting.

[0010] In accordance with an embodiment of the invention there is provided a method comprising the steps of: waiting by a controller of the wireless radio to receive M frames from a set of N radios comprising an active radio and N-l non-active radios; computing with the controller a normalized received signal strength indication (RSSI) average of the M for each radio within the set of N radios; determining with the controller if an RSSI average of any non-active radio of the N-l non- active radios is greater than the RSSI average of the active radio by a defined margin; upon a negative determination that any RSSI average of any non-active radio RSSI of the N-l non- active radios is greater than the RSSI average of the active radio by the defined margin the method returns to the step of waiting; upon a positive determination that an RSSI average of a defined non-active radio RSSI is greater than the active radio RSSI average of the active radio by the defined margin the controller reconfigures such that the defined non-active radio becomes the active radio and the previously active radio becomes a non-active radio before returning to the step of waiting; and

M and N are positive integers, N > 2 and M > 1.

[0011] In accordance with an embodiment of the invention there is provided a method comprising the steps of: configurating a wireless radio to receive data upon a frequency band of a set of frequency bands; waiting a defined delay; performing a listen-before-talk process to determine whether the frequency band of a set of frequency bands is clear; determining whether the listen-before -talk process was aborted; upon determining that the listen-before-talk process was aborted configuring the wireless radio to another frequency band of a set of frequency bands and looping back to the step of waiting.

[0012] In accordance with an embodiment of the invention there is provided a method comprising the steps of: splitting with a processor an uncompressed audio stream to configure the payload of a wireless link between a wireless radio comprising the processor and another wireless radio; determining whether the wireless radio has enabled fallback; upon a positive determination that fallback has been enabled executing the steps of: compressing the split uncompressed audio to generate compressed audio; and transmitting the compressed audio; and upon a negative determination that fallback has been enabled transmitting the split uncompressed audio.

[0013] In accordance with an embodiment of the invention there is provided a method comprising the steps of: establishing a link between a wireless radio and another wireless radio according to a current transmission mode; determining a size of a transmission queue at the wireless radio for the link; determining whether the size of the transmission quote exceeds a threshold value; upon a negative determination that the size of the transmission quote exceeds the threshold value transmitting a frame according to the current transmission mode and returning to the step of determining the size of the transmission queue; and upon a positive determination that the size of the transmission quote exceeds the threshold value establishing a fallback trigger to thereby establish a fallback mode of the wireless radio wherein data to be transmitted within subsequent frames is compressed.

[0014] In accordance with an embodiment of the invention there is provided a method comprising the steps of: establishing a link between a wireless radio and another wireless radio according to a current transmission mode; determining current values of a link margin for the link and a clear channel assessment for the link; determining whether the current value of the link margin for the link exceeds a threshold value and the current value for the clear channel assessment is below another threshold value; upon a negative determination that the current value of the link margin for the link exceeds the threshold value and the current value for the clear channel assessment is below the another threshold value transmitting a frame according to the current transmission mode and returning to the step of determining the current values of the link margin for the link and the clear channel assessment for the link; and upon a positive determination that the current value of the link margin for the link exceeds the threshold value and the current value for the clear channel assessment is below the another threshold value clearing a fallback trigger to thereby establish transmission of data within subsequent frames uncompressed.

[0015] In accordance with an embodiment of the invention there is provided a method comprising the steps of: establishing a link between a wireless radio and another wireless radio according to a current transmission mode; transmitting a dummy frame one a retransmission timeslot of a set of retransmission timeslots defined for a channel N of M channels of the link; determining whether the dummy frame transmission was successful; upon a positive determination that the dummy frame transmission was successful proceeding to the step of determining whether all M channels have been established as clear; upon a negative determination that the dummy frame transmission was successful executing a wait of defined duration and returning to the step of transmitting the dummy frame; determining whether all M channels of the link have been established as clear; upon a positive determination that all M channels of the link have been established as clear clearing a fallback flag or fallback trigger associated with the link; and upon a negative determination that all M channels of the link have been established as clear executing a wait of another defined duration, changing the channel N to a channel not yet verified as clear of the M channels of the link and returning to the step of transmitting the dummy frame; wherein when the fallback flag or fallback trigger associated with the link is set the data to be transmitted is compressed prior to transmission and when the fallback flag or fallback trigger associated with the link is not set the data to be transmitted is not compressed prior to transmission.

[0016] Other aspects and features of the present invention will become apparent to those ordinarily skilled in the art upon review of the following description of specific embodiments of the invention in conjunction with the accompanying figures.

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Embodiments of the present invention will now be described, by way of example only, with reference to the attached Figures, wherein:

[0018] Figure 1 depicts applications of UWB transmitters, receivers, and systems according to embodiments of the invention;

[0019] Figure 2 depicts a block diagram of a UWB transmitter according to an embodiment of the invention;

[0020] Figure 3A depicts a block diagram of a UWB transmitter according to an embodiment of the invention supporting biphasic phase scrambling;

[0021] Figure 3B depicts a block diagram of a UWB transmitter according to an embodiment of the invention employing dynamically configurable and programmable pulse sequences;

[0022] Figure 3C depicts schematically a multi -pulse symbol UWB protocol according to an embodiment of the invention; [0023] Figure 4 depicts a block diagram of a UWB receiver according to an embodiment of the invention;

[0024] Figure 5 depicts a receiver circuit schematic for a UWB receiver according to an embodiment of the invention;

[0025] Figure 6 depicts a circuit schematic for a UWB transceiver according to an embodiment of the invention;

[0026] Figure 7 depicts exemplary regulatory spectral masks for different jurisdictions globally;

[0027] Figure 8 depicts schematics of an antenna module according to an embodiment of the invention employing embedded open stub, bent open stub and rear ground plane slot filters within the microstrip lines of a differential antenna;

[0028] Figure 9 depicts the differential loss, SI 1, of the antenna module depicted in Figure 8;

[0029] Figure 10 depicts the differential S parameter, S 11, of the antenna module depicted in Figure 8;

[0030] Figure 11 depicts the antenna peak gain of the antenna module depicted in Figure 8;

[0031] Figure 12 depicts the antenna radiation pattern of the antenna module depicted in Figure 8;

[0032] Figure 13 depicts a schematic of a compact differential antenna according to an embodiment of the invention;

[0033] Figures 14 and 15 depict antenna impedance matching of the differential antenna as function of width and length of the printed circuit board (PCB) of the compact differential antenna depicted in Figure 13;

[0034] Figures 16 and 17 depict the total radiation efficiency and peak realized antenna gain of the compact differential antenna depicted in Figure 13;

[0035] Figure 18 depicts the free space radiation patterns of the compact differential antenna depicted in Figure 13;

[0036] Figure 19 depicts an algorithm according to an embodiment of the invention with respect to a radio determining a clear-to-send decision;

[0037] Figure 20 depicts an algorithm according to an embodiment of the invention wherein a controller determines which radio of a set of active radios to employ;

[0038] Figure 21 depicts an algorithm according to an embodiment of the invention wherein a controller determines whether to switch between a currently active radio of a set of radios to another radio of radios; [0039] Figure 22 depicts an algorithm with respect to concurrent operation of radios according to an embodiment of the invention;

[0040] Figure 23 depicts an algorithm for an audio transmission process under a fallback condition according to an embodiment of the invention;

[0041] Figure 24 depicts an algorithm for a downstream fallback process according to an embodiment of the invention;

[0042] Figure 25 depicts an algorithm for an upstream fallback process according to an embodiment of the invention;

[0043] Figure 26 depicts an algorithm for an upstream fallback process according to an embodiment of the invention;

[0044] Figure 27 depicts an exemplary application of fallback processes applied to a computer peripheral, a gaming mouse;

[0045] Figure 28 depicts time of flight ranging measurements for a pair of antennas at in aligned and cross-polarizations; ANTENNA POSITIONING FROM RANGING INFORMATION

[0046] Figure 29 depicts a process flow for a determination of antenna positioning established from ranging information;

[0047] Figure 30 depicts detection of an “aggressor” node based upon clear channel assessments (CCA) as part of a listen before synchronisation process;

[0048] Figure 31 depicts graphically the validation steps of a power-up time finding algorithm according to an embodiment of the invention within a listen before synchronisation process according to an embodiment of the invention;

[0049] Figures 32 to 35 depict in detail the validation steps of the power-up time finding algorithm according to an embodiment of the invention;

[0050] Figure 36 depicts the results of repeatability and consistency tests for the power-up time finding algorithm according to an embodiment of the invention; and

[0051] Figures 37 and 38 depict exemplary scenarios for a distributed desynchronization system architecture (DDSA) according to an embodiment of the invention.

DETAILED DESCRIPTION

[0052] The present invention is directed to ultra-wideband wireless radios and more particularly to configuring ultra-wideband transmitters, ultra-wideband receivers and ultra- wideband transceivers for enhanced ultra-wideband wireless link performance. [0053] The ensuing description provides exemplary embodiment(s) only, and is not intended to limit the scope, applicability or configuration of the disclosure. Rather, the ensuing description of the exemplary embodiment(s) will provide those skilled in the art with an enabling description for implementing an exemplary embodiment. It being understood that various changes may be made in the function and arrangement of elements without departing from the spirit and scope as set forth in the appended claims.

[0054] An “artificial intelligence system” (referred to hereafter as artificial intelligence, Al) as used herein, and throughout disclosure, refers to machine intelligence or machine learning in contrast to natural intelligence. An Al may refer to analytical, human inspired, or humanized artificial intelligence. An Al may refer to the use of one or more machine learning algorithms and/or processes. An Al may employ one or more of an artificial network, decision trees, support vector machines, Bayesian networks, and genetic algorithms. An Al may employ a training model or federated learning.

[0055] “Machine Learning” (ML) or more specifically machine learning processes as used herein refers to, but is not limited, to programs, algorithms or software tools, which allow a given device or program to leam to adapt its functionality based on information processed by it or by other independent processes. These learning processes are in practice, gathered from the result of said process which produce data and or algorithms that lend themselves to prediction. This prediction process allows ML-capable devices to behave according to guidelines initially established within its own programming but evolved as a result of the ML. A machine learning algorithm or machining learning process as employed by an Al may include, but not be limited to, supervised learning, unsupervised learning, cluster analysis, reinforcement learning, feature learning, sparse dictionary learning, anomaly detection, association rule learning, inductive logic programming.

[0056] “Electronic content” (also referred to as “content” or “digital content”) as used herein may refer to, but is not limited to, any type of content that exists in the form of digital data as stored, transmitted, received and / or converted wherein one or more of these steps may be analog although generally these steps will be digital. Forms of digital content include, but are not limited to, information that is digitally broadcast, streamed or contained in discrete files. Viewed narrowly, types of digital content include popular media types such as MP3, JPG, AVI, TIFF, AAC, TXT, RTF, HTML, XHTML, PDF, XLS, SVG, WMA, MP4, FLV, and PPT, for example, as well as others. Within a broader approach digital content may include any type of digital information, e.g. digitally updated weather forecast, a GPS map, an eBook, a photograph, a video, a Vine™, a blog posting, a Facebook™ posting, a Twitter™ tweet, online TV, etc. The digital content may be any digital data that is at least one of generated, selected, created, modified, and transmitted in response to a user request, said request may be a query, a search, a trigger, an alarm, and a message for example.

[0057] 0. IMPULSE RADIO ULTRA WIDEBAND SYSTEM

[0058] As discussed supra UWB offers many potential advantages such as high data rate, low- cost implementation, and low transmit power, ranging, multipath immunity, and low interference. However, due to low emission levels permitted by regulatory agencies such UWB systems tend to be short-range indoor applications but it would be evident that a variety of other applications may be considered where such regulatory restrictions are relaxed and / or not present addressing military and civilian requirements for communications between individuals, electronic devices, control centers, and electronic systems for example.

[0059] Accordingly, UWB systems are well-suited to short-distance applications in a variety of environments, such as depicted in Figure 1 including peripheral and device interconnections, as exemplified by first Residential Environment 110, sensor networks, as exemplified by second Residential Environment 120, control and communications, as exemplified by Industrial Environment 130, Medical Systems 150, and personal area networks (PAN), as exemplified by PAN 140. For example, with PAN 140 a user may have associated with them, for example worn discretely, implanted or within an item of smart clothing etc. a variety of sensors including, but not limited to, those providing acoustic environment information via MEMS microphone, user breathing analysis through lung capacity sensor, global positioning via GPS sensor, their temperature and / or ambient temperature via thermometer, and blood oxygenation through pulse oximeter. These are augmented by exertion data acquired by muscle activity sensor, motion data via 3D motion sensor (e.g. 3D accelerometer), user weight / carrying data from pressure sensor and walking / running data from a pedometer. These may be employed in isolation or in conjunction with other data including, for example, data acquired from medical devices associated with the user such as depicted in Medical Systems 150. As depicted these medical devices may include, but are not limited to, deep brain neurostimulators /implants, cochlearimplant, cardiac defibrillator / pacemaker, gastric stimulator, insulin pump, and foot implants.

[0060] The Federal Communications Commission (FCC) regulations for UWB reserved the unlicensed frequency band between 3.1GHz and 10.6GHz for indoor UWB wireless communication system wherein the low regulated transmitted power allows such UWB systems to coexist with other licensed and unlicensed narrowband systems. Therefore, the limited resources of spectrum can be used more efficiently. On the other hand, with its ultra- wide bandwidth, a UWB system has a capacity much higher than the current narrowband systems for short range applications. Two possible techniques for implementing UWB communications are Impulse Radio (IR) UWB and multi -carrier or multi -band (MB) UWB. IR-UWB exploits the transmission of ultra-short (of the order of nanosecond) pulses, although in some instances in order to increase the processing gain more than one pulse represents a symbol. In contrast MB -UWB systems use orthogonal frequency division multiplexing (OFDM) techniques to transmit the information on each of the sub-bands. Whilst OFDM has several good properties, including high spectral efficiency, robustness to RF and multi-path interferences. However, it has several drawbacks such as up and down conversion, requiring mixers and their associated high power consumption, and is very sensitive to inaccuracies in frequency, clock, and phase. Similarly, nonlinear amplification destroys the orthogonality of OFDM. Accordingly, MB-UWB is not suitable for low-power and low cost applications.

[0061] In contrast IR-UWB offers several advantages, including unlicensed usage of several gigahertz of spectrum, offers great flexibility of spectrum usage, and adaptive transceiver designs can be used for optimizing system performance as a function of the data rate, operation range, available power, demanded quality of service, and user preference. Further, multi-Gb/s data-rate transmission over very short range is possible and due to the ultra-short pulses within IR-UWB it is very robust against multipath interference, and more multipath components can be resolved at the receiver in some implementations, resulting in higher performance. Further, the ultra-short pulses support sub-centimeter ranging whilst the lack of up and down conversion allows for reduced implementation costs and lower power transceiver implementations. Beneficially, ultra-short pulses and low power transmissions make IR-UWB communications hard to eavesdrop upon.

[0062] An IR-UWB transmitter as described below in respect of embodiments of the invention in with reference to Figures 2 and 3 respectively exploits an on-demand oscillator following a pulse generator in order to up-convert the pulses from the pulse generated whilst avoiding the requirement of a separate mixer. Implementable in standard CMOS logic both the pulse generator and the on-demand oscillator are digitally tunable in order to provide control over the pulse bandwidth and center frequency. Further, by exploiting a digitally controlled ring oscillator for the on-demand oscillator the IR-UWB transmitter is designed to allow very quick frequency adjustments on the order of the pulse repetition rate (PRR). Beneficially this technique provides the same advantages as MB -OFDM in respect of spectrum configurability, achieved by sequentially changing the transmitted spectrum using a frequency hopping scheme, whilst maintaining the benefits of IR-UWB. Further, by providing advanced duty cycling with fast power up time combined with On-Off Shift Keying (OOK) modulation the IR-UWB according to embodiments of the invention allows significant reductions in power consumption by exploiting the low duty cycle of a UWB symbol and the fact that only half the symbols require sending energy.

[0063] In addition to defining the operating frequency range for UWB systems the different regulatory bodies all specify and enforce a specific power spectral density (PSD) mask for UWB communications. A PSD mask as may be employed in respect of embodiments of the invention is the FCC mask for which mask data are summarized in Table 1 below for the 3100MHz- 10600MHz (3.1GHz-10.6GHz) range.

Table 1: FCC Masks for Indoor - Outdoor for Different Frequency Bands

[0064] Accordingly, it would be evident that the upper limit of -41.3 dB/MHz across the 3.1GHz-10.6GHz frequency range is the same limit imposed on unintentional radiation for a given frequency in order not to interfere with other radios. Basically, for a given frequency, the UWB radio operates under the allowed noise level which creates the relationship presented in Equation (1) between E_p, the transmitted energy per pulse, the maximum spectral power S' , the bandwidth B , the bit rate

and the number of pulses per bits N_ppl.

E_p N_ppb R_b <S B (1)

[0065] The IEEE has published a few standards for a physical layer (PHY) for UWB radio in Personal Area Networks (IEEE 802.15.4a- 2007), Body Area Networks (IEEE 802.15.4a-2007) and Radio-Frequency Identification (IEEE 802.15.4f-2012). These standards use mostly relatively large pulses resulting in relatively narrow bandwidth which is up converted to a specific center frequency in order to fill predetermined channels. The data is encoded using pulse-position-modulation (PPM) and bi-phasic shift keying (BPSK) is used to encode redundancy data. Every bit consists of one or more pulses scrambled in phase depending on the target data rate. These standards allow considerable flexibility on channel availability and data rates. The standard also defines the preamble, headers for the data packet and ranging protocol.

[0066] These IEEE standards are designed with multiple users in mind and use different channels to transmit the data, thereby putting a heavy constraint on pulse bandwidth and limiting the transmitted energy. Prior art on non-standard transmitter attempts to make better use of the available spectrum by using narrow pulses, which therefore have a larger bandwidth thereby increasing the maximum transmitted energy according to Equation (1). Accordingly, these transmitters are non-standard and were also designed for different data rates, frequencies, pulse width, etc. Additionally, they also used various encoding schemes, most notably PPM, OOK or BPSK.

[0067] Within the work described below the inventors have established improvements with respect to UWB systems, UWB transmitters and energy based UWB receivers which are capable of generating and adapting to a variety of IR-UWB pulses and bit encoding schemes thereby supporting communications from both IR-UWB transmitters compliant to IEEE standards as well as those that are non-standard. These improvements are made with respect to UWB transmitters, UWB receivers, UWB transceivers and UWB systems such as those described and depicted by the inventors within WO/2015/103,692 “Systems and Methods Relating to Ultra-Wideband Broadcasting comprising Dynamic Frequency and Bandwidth Hopping” (PCT/CA2015/000,007, filed January 7, 2015); WO/2016/191,851 “Systems and Methods for Spectrally Efficient and Energy Efficient Ultra-Wideband Impulse Radios with Scalable Data Rates” (PCT/CA2016/000, 161 filed May 31, 2016); WO/2019/000,075 “Energy Efficient Ultra-Wideband Impulse Radio Systems and Methods” (PCT/CA2018/000, 135 filed June 29, 2018); WO/2020/186,332 “Methods and Systems for Ultra-Wideband (UWB) Receivers” (PCT/CA2020/000,029 filed March 18, 2020); WO/2020/186,333 “Ultra- Wideband (UWB) Transmitter and Receiver Circuits” filed March 18, 2020; and WO/2020/186,334 “Ultra-Wideband (UWB) Link Configuration Methods and Systems” filed March 18, 2020.

[0068] 1. IR-UWB TRANSMITTER CIRCUIT

[0069] Referring to Figure 2 there is depicted schematically an exemplary architecture for an IR-UWB transmitter 200 according to embodiments of the invention which is composed of five main blocks plus the antenna. First a programmable impulse is produced by a pulse generator 230 at clocked intervals when the data signal from AND gate 210 is high based upon control signals presented to the AND gate 210. The pulses from the pulse generator 230 are then up converted with a programmable multi-loop digitally controlled ring oscillator (DCRO) 240. The output from the DCRO 240 is then coupled to a variable gain amplifier (VGA) 250 in order to compensate for any frequency dependency of the pulse amplitude. Finally, a driver 260 feeds the antenna 270, overcoming typical package parasitics, such as arising from packaging the transceiver within a quad-flat no-leads (QFN) package. In order to further reduce the power consumption of the IR-UWB transmitter (IR-UWB-Tx) 200 according to embodiments of the invention a power cycling controller 220 dynamically switches on or off these functional blocks when the data signal is low.

[0070] Now referring to Figure 3A there is depicted schematically a block diagram 300 of an exemplary IR-UWB transmitter according to embodiments of the invention supporting biphasic phase scrambling. In comparison to the IR-UWB transmitter 200 in Figure 2 for an IR-UWB according to embodiments of the invention without biphasic phase shifting rather than being composed of five main blocks plus the antenna the Biphasic Phase Shifting IR- UWB (BPS-IR-UWB) transmitter comprises 6 main blocks. First a programmable impulse is produced by a pulse generator 330 at clocked intervals when the data signal from AND gate 310 is high based upon control signals presented to the AND gate 310. The pulses from the pulse generator 330 are then up converted with a programmable multi-loop digitally controlled ring oscillator (DCRO) 340. The output from the DCRO 340 is then coupled to a dual-output amplifier (VGA) 350 both in order to compensate for any frequency dependency of the pulse amplitude but also to generate dual phase shifted output signals that are coupled to a switch 360 which selects one of the two signals to couple to the output power amplifier (driver) 380 under the action of the switch control signal “S” applied to the switch 360. Note that a similar phase selection scheme could be implemented by affecting the startup conditions for DCRO 340 in order to provide the two phases. This would preclude the need for switch 360 at the cost of an added control startup condition control signal on DCRO 340.

[0071] The output power amplifier 380 feeds the antenna 370, overcoming typical package parasitics, such as arising from packaging the transceiver within a quad-flat no-leads (QFN) package. In order to reduce the power consumption of the BPS-IR-UWB transmitter represented by block diagram 300 according to an embodiment of the invention a power cycling controller 320 dynamically switches on or off these functional blocks when the data signal “PC” is low. Accordingly, a BPS-IR-UWB transmitter according to embodiments of the invention transmits pulses with or without phase shift based upon the control signal “S” applied to Switch 360. If this control signal is now fed from a random data generator or a pseudorandom data generator then the resulting pulses coupled to the antenna of the BPS-IR-UWB transmitter will be pseudo-randomly or randomly phase shifted. [0072] Now referring to Figure 3B there is depicted schematically a block diagram 3000 of an exemplary IR-UWB transmitter according to embodiments of the invention. As depicted a Pulse Pattern block 3010 holds a configuration for the pulses used to represent the current symbol. From the symbol-rate clock (i.e. 20 MHz), multiple phases are generated by a Delay Locked Loop (DLL) 3030. The rising edge of each clock phase represents the start of one pulse in the symbol pulse bundle. A Multiplexer 3020 is triggered by the edges of the clock phases and selects the configuration of the current pulse out of the Pulse Pattern block 3010. A pulse generator (Pulser) 3050 generates pulses with a pulse width set by the multiplexer 3020 and enables the Digitally Controlled Oscillator (DCO) 3040 and Power Amplifier (PA) 3060. When enabled, the DCO 3040 generates a Gaussian shaped pulse with frequency set by the multiplexer 3020, which is then amplified by the PA 3060 and radiated by the antenna 3070.

[0073] Accordingly, the Pulse Pattern block 3010 establishes the pulses for a symbol or sequence of symbols. In this manner updating the Pulse Pattern block 3010 adjusts the pulse sequence employed for each symbol and accordingly the Pulse Pattern block 3010 may be dynamically updated based upon one or more factors including, but not limited to, network environment data, predetermined sequence, date, time, geographic location, signal-to-noise ratio (SNR) of received signals, and regulatory mask.

[0074] Referring to Figure 3C there is depicted schematically a multi-pulse symbol UWB protocol according to an embodiment of the invention. Referring to first image 3100 A there is depicted a bit 3160 comprising a series of sub-pulses 3160A to 3160F which are each at frequencies

f₃ ; f₂. Accordingly, the multi -pulse spectrum 3180 of a symbol (bit 3160) is depicted in second image 3100B as obtained conceptually (phase scrambling is omitted for clarity) by summing the individual pulse spectra of the sub-pulses 3160A to 3160C, which increases the bandwidth whilst increasing the total symbol duration, in contrast with single-pulse prior art methods, whilst maintaining the maximum power below the UWB mask 3120. This allows the symbol energy to be maximized while relaxing the timing requirements and level of synchronisation required at the receiver. An arbitrary number of pulses with different sets of parameters may be included within a bundle to tailor the pulse spectrum to a given requirement.

[0075] Accordingly, a bit may be transmitted as a UWB signal comprising a plurality of N pulses each pulse of the N pulses is at a predetermined frequency of a plurality of M frequencies, has a predetermined amplitude, and has a predetermined pulse length; where N>2 and M> 2 and M and N are integers. A pulse repetition rate of an RF signal generator of a UWB transmitter according to embodiments of the invention, such as Pulse Pattern block 3010, Multiplexer 3020, DLL 3030, DCO 3040 and Pulser 3050 in Figure 3B for example, is determined as a function of a clock frequency; the integer N depends on the duration of a bit of the data signal and the pulse repetition rate of the RF signal generator and the plurality of N pulses are transmitted within the duration of the data signal bit. Each bit comprising the plurality of N pulses may comply with an emitted power spectrum density profile

[0076] However, it would also be evident that an RF signal generator of a UWB transmitter according to embodiments of the invention may operate with N=1 and M=l, i.e. single pulse at single frequency within the duration of a bit of the data signal where length of the single pulse is a portion of the duration of the bit of the data signal which may for example be that defined by the pulse repetition rate of the RF signal generator which may be fixed or varied under the action of the clock provided etc.

[0077] However, it would also be evident that an RF signal generator of a UWB transmitter according to embodiments of the invention may operate with N>1 and M=1 where N is an integer, i.e. multiple pulses at the same frequency with the duration of a bit of the data signal.

[0078] Within Figure 3A a Biphasic Phase Shifting IR-UWB (BPS-IR-UWB) transmitter is described wherein a control signal “S” applied to a Switch 360 selects one of the two phases of the amplified signal from the VGA 350. Within other embodiments of the invention pseudorandom biphasic phase shifting may be established through affecting the start-up condition of the DCRO, such as DCRO 340 in Figure 3A.

[0079] However, it would also be evident that an IR-UWB may according to other embodiments of the invention be employed within a Wireless Radio (WR) supporting non-IR modulation and transmission protocols such as those employing coherent modulation techniques such as those within wireless standards which may include, but are not limited to IEEE 802.11, IEEE 802.15, IEEE 802.16, IEEE 802.20, UMTS, GSM 850, GSM 900, GSM 1800, GSM 1900, GPRS, ITU-R 5.138, ITU-R 5.150, ITU-R 5.280, IMT-1000, Bluetooth, WiFi, Ultra-Wideband and WiMAX. Some standards may be a conglomeration of sub-standards such as IEEE 802.11 which may refer to, but is not limited to, IEEE 802.1a, IEEE 802.11b, IEEE 802.11g, or IEEE 802.1 In as well as others under the IEEE 802.11 umbrella.

[0080] Within other embodiments of the invention additional elements may be employed to bypass the Switch 360 such that the dual phase offset outputs of the VGA 350 are coupled to a coherent transmitter functional block such that the dual phase offset outputs are employed within the coherent transmitter functional block as the in-phase and quadrature signals which are then encoded with data. This allows a UWB transmitter or UWB transceiver to exploit the low power signal generation of the IR-UWB comprising at least the Pulse Generator 330, DCRO 340 and VGA 350.

[0081] 2. IR-UWB RECEIVER

[0082] Referring to Figure 4 there is depicted schematically the architecture of an IR-UWB receiver 400 according to embodiments of the invention. Accordingly, the signal from an IR- UWB transmitter is received via an antenna 410 and coupled to a low noise amplifier (LNA) 420 followed by first amplifier 430 wherein the resulting signal is squared by squaring circuit 440 in order to evaluate the amount of energy in the signal. The output of the squaring circuit 440 is then amplified with second amplifier 450, integrated with integration circuit 460 and evaluated by a flash ADC 470 to generate the output signals. Also depicted is Power Cycling Controller 480 which, in a similar manner to the power cycling controller 220 of IR-UWB transmitter 200 in Figure 2, dynamically powers up and down the LNA 420, first and second amplifiers 430 and 450 respectively, squaring circuit 440, and flash ADC 470 to further reduce power consumption in dependence of the circuit’s requirements.

[0083] Referring to Figure 5 there is depicted a schematic of a receiver 500 according to an embodiment of the invention. The RF signal from the antenna 510 is initially amplified by a Low Noise Amplifier (LNA) 520 before being passed to a two stage RF amplifier (AMP1) 530. A first squaring mixer (MIX1) 540 multiplies the signal with itself to convert to the Intermediate Frequency (IF). A three-stage Variable Gain Amplifier (VGA) 550 amplifies the signal further and implements a bandpass filter function. The VGA 550 output is then coupled to a second squaring mixer (MIX2) 560 which down-converts the signal to the baseband frequency. An energy detection circuit 580 comprising a parallel of integrator (INTI and INT2) sums the signal energy, which is digitized by the Analog -to-Digital Converters (ADC1 and ADC2) and sent to a digital processor (not depicted for clarity).

[0084] 3. IR-UWB RECEIVER

[0085] As described within W0/2019/000,075 and WO 2016/191,851 the inventors have established design parameters of millisecond range start-up time from sleep mode and microsecond range start-up time from idle mode by establishing a custom integrated DC/DC converter and duty cycled transceiver circuitry that enables fast circuit start-up / shut-down for optimal power consumption under low (1 kbps) and moderate data rates (10 Mbps ).

[0086] In order to sustain good energy efficiency, the elements of a total UWB transceiver, such as depicted with transceiver 600 in Figure 6 according to embodiments of the invention, has been designed for low static sleep current and fast startup/sleep times. Referring to Figure 6, a battery (3.0 V < V_BATT < 3.6 V ) (not depicted for clarity) powers a low-frequency crystal oscillator 615, sleep counter 620 and bandgap reference 610, all of which are typically always operational although the bandgap reference 610 could be duty cycled within other embodiments of the invention without altering the scope of the claimed invention). Their power consumption limits the minimum power consumption of the system to sub-microwatt level. An integrated buck DC-DC converter 605 is powered by the battery when the system is not in sleep mode, and this provides the supply voltage to the rest of the system with high conversion efficiency. The startup time of the DC-DC converter 605 is on the order of several symbol periods in order to minimize wasted energy. Between sleep periods, the PLL 655 is active to provide the base clock for the system. The receiver 625 and DLL 660 have dedicated power down controls and are only activated during frame transmission / reception. Further, the transmitter is also power cycled through its all-digital architecture which is not depicted as having a separate control. The power consumption of the digital synthesized blocks is low due to the low base clock (e.g. 20 MHz).

[0087] In principle, a power-cycled transceiver achieves linear scaling of power consumption with data rate, thus achieving constant energy efficiency. With a fixed frame size, multiple data rates are obtained by adjusting the length of the sleep period, with the maximum attainable data rate determined by the symbol rate in the frame itself. In order to preserve energy efficiency, the power consumption during sleep must be lower than the average power consumption. For high data rates, powering down the PLL is not required when its consumption does not significantly degrade the overall efficiency. For low data rates, the whole system except the bandgap reference, crystal oscillator, and sleep counter can be shut down during sleep mode. In this case, the millisecond range startup time of the PLL can be insignificant compared to the sleep period, and overall efficiency is also not significantly degraded.

[0088] As depicted the UWB transceiver 600 also comprises a receive / transmit switch 690 coupled to the antenna to selectively couple the transmitter 6000 or receiver 625 to the antenna during transmission and reception respectively. The UWB transceiver 600 also comprises a spectrum configuration circuit 665 (equivalent to Pulse Pattern 3010 in transmitter 3000 in Figure 3B), PHY Processing circuit 650, Link Controller 645, Buffer and Interface circuit 640, and PHY Formatting circuit 635. The UWB transceiver 600 communicates via Link Controller 645 to the Client 605. As such, Link Controller 645 may communicate using a wired protocol (e.g., serial peripheral interface (SPI)) to Client 605, for example.

[0089] 4. COMPACT DIFFERENTIAL ANTENNA [0090] UWB transmitters, UWB receivers and UWB transceivers employ an antenna as a transducer between the wireless UWB signals and the electrical signals coupled to or generated by the UWB circuitry of a UWB transmitter, UWB receiver or UWB transceiver. Many antenna structures have been presented in the prior art for either discrete UWB antennas or UWB antennas supporting diversity techniques to help mitigate effects such as multipath interference. [0091] Accordingly, the inventors have established previously compact antenna diversity structure to employ with UWB transmitters, UWB receivers and UWB transceivers exploiting techniques according to embodiments of the invention which are described and depicted within patent applications including WO/2015/103,692; WO/2016/191,851; W0/2019/000,075, WO/2020/186,332; WO/2020/186,333, WO/2020/186,334, WO/2022/213,183 and

PCT/CA2022/051510 together with other aspects of these UWB devices not described here or elsewhere.

[0092] 5. DIFFERENTIAL ANTENNA WITH INTEGRATED BAND FILTER

[0093] IR-UWB transmitters in many applications must comply with one or more UWB spectral masks that are defined independently by the regulatory bodies around the world based on their currently implemented systems and future frequency plans. These UWB spectral masks defining the emitted and/or received RF power versus frequency for UWB transmitters, UWB receivers and UWB transceivers. Examples of such regulatory receiver UWB spectral masks are depicted in Figure 7 comprising those defined by the European Telecommunications Standards Institute (ETSI) in Europe, the Canadian Radio-television and Telecommunications Commission (CRTC) in Canada , the Federal Communications Commission (FCC) in the United States, and the Japanese and Korean regulatory authorities. As evident from these a common available band is that between 7.25GHz and 8.5 GHz. However, this band is not sufficient for many applications. Accordingly, one product methodology is to define UWB products that comply with each national regulatory requirement. However, this means that multiple stock keeping units (SKUs) are required to support a UWB product that can penetrate worldwide markets.

[0094] Multiple SKUs however create various complexities both in terms of cost of production, marketing, product supply chain management to the manufacturer, distributors and customers. Accordingly, it is beneficial to avoid this as far as possible. As discussed above the operating frequency of an IR-UWB radio can be controlled both by software (via firmware settings) and hardware (via the RF front-end). Accordingly, in order to minimize different hardware variations, it would be beneficial to have a single IR-UWB design that operate across the frequency bands required by different regions and select the appropriate frequency band based on regional regulations through firmware.

[0095] In order to address this the inventors designed and implemented an innovative differential antenna module which has an integrated filtering feature, as well as a wide enough pass band region from 6.5 GHz to 9.0 GHz. The integrated filter rejects undesired signals from 10.6 GHz to 12.75 GHz such that the antenna module complies with the regulatory spectral limits in this frequency range, such as those defined by ETSI and Japan.

[0096] First and second Images 800A and 800B in Figure 8 depict schematics of the antenna structure according to an embodiment of the invention. First Image 800A being a front view whilst second Image 800B is a rear view. The antenna module according to the embodiment of the invention depicted in Figure 8 being 15.47 mm (0.61“) wide and 24.67 mm (0.97“) long. The design being upon an FR4 substrate although other substrates for the antenna module may be employed. The design incorporates the integration of three tightly coupled band rejection filters into the structure. The pair of microstrip lines being disposed either side of a virtual axis of the antenna module which may or may not align with a physical axis of the antenna module. [0097] Each microstrip line of the differential antenna incorporates on the front side an embedded open stub (EOS) 810, a bent open stub (BOS) 820 and a rear ground plane slot (RGPS) 830. The resonant frequency and Q factor of each of these filters on each microstrip line is tuned to produce attenuation from 10.6 GHz to 12.75 GHz whilst keeping the in-band loss as low as possible over 6.5 GHz to 9.0 GHz. The bandwidth of the rejection band was designed to be sufficient to accommodate the specified variations of the permittivity of the FR4 substrate material.

[0098] Figure 9 depicts the radiation efficiency plot of the antenna module of Figure 8. As evident from this the EOS 810, BOS 820 and RGPS 830 provides at least 10 dB attenuation from 10.57 GHz to 13.24 GHz for the permittivity of 4.3. This covers the required rejection band to pass the Japanese regulatory mask. The filter has a good tolerance to permittivity variations and performs well within a range of Er between 4.6 and 4.1. The antenna has a maximum loss of 1.24 dB (radiation loss + insertion loss) at 6.5 GHz. Moreover, the antenna has a good rejection below 6 GHz which will help avoiding Wi-Fi interference as well as fitting the required spectral masks.

[0099] Figure 10 depicts the differential S parameter, Sil, of the antenna module depicted in Figure 8. As evident from this the antenna module delivers good impedance matching performance from 6.3 GHz to 9.8 GHz which covers the required frequency bands for worldwide operation of an IR-UWB device. Figures 11 and 12 depict the antenna peak realized gain and radiation patterns for the antenna module depicted in Figure 8. The antenna has a maximum peak realized gain of 2.3 dB at 9.0 GHz in free space as depicted in Figure 11 where the band rejection feature of this antenna module is also evident in this plot.

[00100] 6. UWB TRANSCEIVER LISTEN BEFORE TALK ALGORITHMS

[00101] Within many transmission protocols within the prior art a wireless transmitter is enabled to send data based upon it establishing a “clear-to-send” (CTS) condition. The CTS may be established in dependence upon a CTS frame or CTS data received via a wireless receiver, for example, associated with the wireless transmitter as part of an overall “handshake” between the device comprising the transmitter and another device, where the other device may be another device or a network controller. However, such handshake protocols take time to execute and can therefore limit the overall efficiency of data transmission by the wireless transmitter.

[00102] The inventors have previously described within PCT/CA2022/050510 an alternative methodology wherein a decision with respect to determining the CTS is made autonomously by the wireless transmitter where the CTS determination was based upon the receiver periodically waking up as defined by its protocol and performing a Clear Channel Assessment (CCA). The CCA Assessment being based upon determining whether a CCA threshold is exceeded where the CCA threshold is established in dependence upon a link quality indicator (LQI). The determination is made by comparing the CCA threshold and the average noise floor by monitoring the signal’s received number of signals indicator (RNSI) every time a frame is received and computing a running average. Whilst itself novel, where an IR-UWB employs energy detection of a UWB receiver to determine a clear to send decision, the determination that the CTS condition has been met is made for a current frame wherein the transmitter will transmit in the next frame. The novelty being that unlike the prior art there is no specific flag or data within a frame within the protocol. This approach may be applied to other radios without departing from the scope of the invention.

[00103] The inventors have extended this concept by employing energy detection within an IR-UWB, although it may be applied to other radios without departing from the scope of the invention, where the CTS determination is made by analysing a "frame" prior to an actual frame period. Upon establishing that the CTS determination is a “clear-to-send” then the transmitter within embodiments of the invention will immediately start to transmit data as it has determined the channel is clear. An exemplary process according to an embodiment of the invention is described below with respect to Figure 19. [00104] A “frame” with respect to this determination of CTS may be a dedicated guardband defined prior to an actual data frame. Within embodiments of the invention the “frame” may be a portion a “frame.” Within embodiments of the invention the concept described in Figure 19 a single channel is assumed but the processes may be applied to frequency hopping systems where transceivers follow a common pattern and accordingly, a radio may be analysing and determining the CTS on the next hop frequency or hop sub-band. Accordingly, a transmitter may, in principle, be transmitting on a current hop frequency or hop sub-band whilst determining whether it can continue transmitting on the next hop frequency or hop sub-band. Accordingly, a transmitter may, in principle, be currently blocked from transmitting on a current hop frequency or hop sub-band whilst determining whether it can continue transmitting on the next hop frequency or hop sub-band.

[00105] Referring to Figure 19 there is depicted a Flow 1900 according to an embodiment of the invention for a “Listen Before Talk” (LIBETA) process. Flow 1900 comprising first to eighth steps 1910 to 1980, which comprise:

• First Step 1910 “Set Radio in Rx” where the radio is configured to listen on a defined channel.

• Second Step 1920 “Set Threshold” wherein the energy detection threshold is set.

• Third Step 1930 “Listen To Channel” wherein the radio listens for a predefined period of time.

• Fourth Step 1940 “Above Threshold?” wherein a determination is made as to whether the received energy detected during third Step 1930 exceeds the threshold set in second Step 1920. Upon a positive determination the Flow 1900 proceeds to sixth Step 1960 otherwise it proceeds to fifth Step 1950.

• Fifth Step 1950 “Transmit Frame” where the radio transmits the next frame of data which is transmitted immediately the channel is available.

• Sixth Step 1960 “Max Retry?” where a determination is made as to whether a number of listening retries has been exceeded or not. Upon a positive determination the Flow 1900 proceeds to seventh Step 1970 otherwise it proceeds to eighth Step 1980.

• Seventh Step 1970 “Wait CCA_DELAY” wherein the Flow 1900 waits for a predefined or pseudo-random wait time before proceeding to third Step 1930 and listening again. • Eighth Step 1980 “Abort or TX Anyway” wherein if the channel is not available the Flow 1900 may abort, within some embodiments of the invention, or the transmitter can transmit anyway, within other embodiments of the invention.

[00106] Within first Step 1910 the channel listened to may be current channel, a next frequency within a frequency hopping pattern, a next sub-band of band hopping pattern or another channel the radio will move to. Optionally, within an embodiment of the invention multiple channels may be sensed sequentially or according to the capabilities of the UWB transceiver concurrently. Where the UWB transceiver is working on a portion of a frame then it can monitor multiple channels within an overall frame.

[00107] Within second Step 1920 the energy detection threshold may be fixed or a dynamic value may be employed. The dynamic value may be established in dependence upon analysis of channel data, including for example RNSI and/or RSSI history. The analysis may be performed by one or more ML and/or Al processes. Within an embodiment of the invention the threshold value may be established in dependence upon data relating to channels and/or links relating to packet error rate such that the threshold is set such that the subsequent transmissions have minimum packet error rate.

[00108] Within third step 1930 the predefined period of time the radio listens for may be a subset of a frame or a complete frame.

[00109] Within an alternate embodiment of the invention the determinations made in fourth Step 1940 may be employed as part of an additional process to predict future frame probability. This may employ on or more ML or Al processes.

[00110] The number of listening retries in sixth Step 1960 may be fixed or it may be varied based upon one or more factors including, for example, historical data and channel data.

[00111] The delay, CCA_DELAY, in step 1970 may be fixed, variable or random. Whether the delay is established as fixed, variable or random may be established in dependence upon one or more factors including, but not limited to, historical data, recent channel data and current channel data. What type of delay is established and where the delay is fixed or variable the magnitude of the delay may be defined by one or more ML or Al processes.

[00112] Within an embodiment of the invention the Flow 1900 the threshold to determine if CCA triggers a deferral or not can be programmed in at link initiation. However, it could also be dynamically adjusted based on channel data, such as the RNSI value, received signal strength indication (RSSI) value etc. in order to allow Flow 1900 to be agile in some application environments. [00113] The enhanced process supports a UWB device transmitting immediately upon determining a clear to send condition. This allows for latency to be reduced within UWB systems.

[00114] 7. HYBRID UWB - NARROWBAND (COHERENT - NON COHERENT) ARCHITECTURES

[00115] Non-coherent radio systems are simple in design and generally do not require expensive hardware or sophisticated signal processing. Accordingly, non-coherent radios generally consume less power and generate less heat making them ideal for many applications, particularly within battery-operated devices. However, coherent radios can be more sensitive allowing them to receive weaker signals and provide improved coverage. Coherent radios also offer improved interference rejection and can maintain signal quality even in noisy environments.

[00116] An IR-UWB transmitter as described above can support operation within noncoherent links through energy detection receivers whether the transmitted signals are single frequency or multi -pulse bundles with pulses at a plurality of frequencies. However, as also outlined above such an IR-UWB transmitter operating at a single frequency, and optionally as outlined below with respect to section 21, with fine frequency offset, can support transmission of signals to a coherent receiver. Simple amplitude modulation can be implemented through the self-mixing properties of the IR-UWB receivers described within this specification or more complex modulation schemes can be employed with dedicated coherent receiver circuits etc.

[00117] A wireless transceiver that supports both a coherent and a non-coherent mode offers several advantages. Firstly, it provides flexibility in choosing the best mode for a specific application. For example, when high sensitivity is required, the transceiver can operate in coherent mode to support faster/higher performance transmission and receipt of data. On the other hand other applications, such as those in low power battery-operated devices, the noncoherent mode can be used to conserve power and reduce heat.

[00118] Secondly, the ability to switch between modes allows for enhanced adaptation to changing conditions in the environment. In noisy environments, for example, the transceiver can operate in coherent mode to reject interference and maintain signal quality. The presence of both modes also enables the transceiver to adjust its performance based on the available resources, such as power or processing capacity. Overall, a wireless transceiver with both coherent and non-coherent mode provides a versatile solution that can meet the demands of various applications while offering improved performance and reliability. [00119] This mode switching can be made from frame to frame dynamically by monitoring link conditions and having the receiver adapt its detector dynamically as required by channel conditions.

[00120] The choice between coherent and non-coherent mode can be based on several metrics that may be used discretely or combined, including, but not limited to:

• 1. Sensitivity: A coherent mode can provide improved sensitivity, allowing the transceiver to receive weaker signals and provide improved coverage.

• 2. Interference rejection: In noisy environments, coherent mode can reject interference and maintain signal quality.

• 3. Power consumption: For low power, battery-operated devices, a non-coherent mode may be preferred as it generally consumes less power and generates less heat.

• 4. Data rate: For high data rate applications, coherent mode may be preferred as these generally can support higher data rates.

• 5. Processing requirements: Coherent transmission modes requires more sophisticated signal processing and resources which may not be available at a certain time, while non-coherent mode requires less processing.

[00121] Coherent and non-coherent modes within a single transceiver can also use correlation to increase link budget at the expense of airtime. Clear channel Assessment (CCA) can also be used with each of these two modes to improve co-existence with other wireless devices. For instance CCA can be used in coherent mode to render it more sensitive and less prone to hidden nodes, while higher duty cycle data communication can be done through the lower power noncoherent mode.

[00122] Accordingly, the inventors have established a hybrid PHY combining IEEE PHY with the PHY techniques of IR-UWB as described within this specification. The embodiments of the invention described within this specification support the integration of a narrow band radio with a UWB radio for example. This hybrid PHY (i.e. a PHY supporting coherent and non-coherent operational modes of data transmission) provides transceivers with the ability to manage low power low accuracy ranging / communications with discrete or dynamic swapping to high power high accuracy ranging / communications, discrete or dynamic operating in coherent and/or non-coherent modes. Accordingly, a transceiver may form part of a device that employs low power non-coherent communications for a period of time and then high power coherent communications for another period of time. Such a transceiver could therefore support data accumulation from a number of local devices, sensors etc. via short-range non-coherent links and then transmit this to IEEE PHY compatible devices via medium or long range coherent link(s).

[00123] For example, a transceiver may support non-coherent audio and Bluetooth Low Energy (BLE) where it may fallback to BLE on link degradation or non-coherent on power limitations, employs timing / channel plans / etc.

[00124] Accordingly, a hybrid PHY according to an embodiment of the invention would support wireless devices dynamically switching between standard UWB and non-standard UWB to reduce power consumption and latency (standard -> non-standard) or increase range/support IEEE PHY (non-standard -> standard).

[00125] Accordingly, a hybrid PHY would support wireless devices dynamically switching between narrowband radio and non-standard UWB to reduce power consumption and latency (narrowband -> non-standard) or increase range/support (non-standard -> narrowband) where narrowband equates to IEEE PHY protocols or other international wireless standard protocols that are coherence based.

[00126] It would be evident that one or more parameters may be monitored and evaluated against thresholds or presets in order to determine when a transceiver supporting multiple modes compliant to a hybrid PHY would swap between modes.

[00127] 8. ISI PREAMBLE DETECTION

[00128] Within PCT/CA2022/051510 the inventors disclosed a method of performing intersymbol interference (ISI) detection. The disclosed method employs multiple accumulators, which hold phase data which is the accumulated values for the preamble employed by a ranging function by the IR-UWB, in conjunction with an appropriate preamble pattern length. However, the inventors have extended this wherein by using a predefined preamble sequence the IR-UWB can determine if there is bleeding from one symbol to the next symbol. Accordingly, if bleed-over is determined, i.e. there is ISI, then a guard band employed between sequential symbols can be increased. If no bleed-over is detected, i.e. there is no ISI, then the guard band can be decreased. The guard band may, within other embodiments of the invention be reduced if a measure of the bleed-over reduces. Within embodiments of the invention a PHY header within the transmitted data from the transmitter may include an indication of the degree of ISI mitigation being employed, e.g. the length of the guard-band, such that the receiving UWB device can factor this guard band into its timing process for transmitting.

[00129] 9. COMPACT DIFFERENTIAL ANTENNA WITH GROUND PLANE TUNING [00130] Within many applications of IR-UWB devices a compact differential UWB antenna is beneficial in order to reduce the overall footprint of the IR-UWB device itself and/or the device or system the IR-UWB device is associated with or integrated within. Referring to Figure 13 there is depicted a schematic of a compact differential UWB antenna according to an embodiment of the invention. The embodiment depicted in Figure 13 being designed for direct connection to the output ports (RFN and RFP) of a commercial IR-UWB radio, SRI 020 as marketed by Spark Microsystems Inc. of Montreal, Canada.

[00131] As depicted the differential antenna is 9.0 mm (0.35“) by 9.0 mm (0.35”) formed upon a printed circuit board (PCB) with a PCB ground plane dimension of 25.0 mm (0.98“) by 25.0 mm (0.98”). In this configuration the antenna provides an impedance matching bandwidth of 7.25 GHz to 9.2 GHz. However, the impedance bandwidth of the antenna is a function of the ground plane width. The Vivaldi antenna, similar to the differential Vivaldi antennae described by the inventors within PCT/CA2022/051510 “Ultra Wideband Radio Devices and Methods”, has a horizontal polarization in the ±Z orientations as well as +Y orientation. In the ±X orientations it exhibits a vertical polarization.

[00132] A benefit of the antenna according to these embodiments of the invention when compared to the previously presented differential Vivaldi antenna is that it does not require a clearance on the PCB which facilitates its integration into different products. Moreover, its total occupied area is 9.0 mm (0.35“) by 9.0 mm (0.35”), i.e. 81 mm² (0.1225 square inches) and the remainder of the PCB can be populated. This is a significant size reduction from 12.0 mm (0.47“) X15.0 mm (0.59“), i.e. 180 mm2 (0.277 square inches) required for the previous version of the differential Vivaldi antenna (i.e. about 50%) in PCT/CA2022/051510. The elements of the inventors design innovations in achieving the footprint reduction include folding the exciting transmission lines and slot lines as well as tuning the design so that the surrounding ground plane becomes part of the antenna itself. The reduced footprint allows for the antenna to be integrated into small footprint products directly such as UWB “dongles” etc. [00133] The embodiment of the inventive antenna depicted in Figure 13 was tuned to provide good impedance matching to the output impedance of the Spark™ SR1020 radio (i.e. 30 +i9 Q at 7.5 GHz). As the innovative antenna now incorporates the surrounding ground plane as part of the antenna the impedance matching of the antenna and its operating frequency are now a function of the PCB geometry and can be tuned accordingly such that the antenna gain and efficiency can also be tuned with the dimensional parameters of the ground plane and therein the PCB if its footprint is limited by the antenna ground plane. As depicted in Figure 13 the inventors define W_Port to represent the antenna ground plane width (along the X-axis) and L_Port to represent the antenna ground plane length (along the Y-axis).

[00134] Referring to Figure 14 there are depicted the plots of antenna differential impedance matching (Sil) as W_port is varied from 20.0 mm (0.79“) to 50.0 mm (1.97“). It is worth noting that, as observed in Figure 14, for W_Port = 45.0 mm (1.77“), this antenna covers a large frequency band from 6.8 GHz to 9.76 GHz with a differential SI 1 below -10 dB. Figure 15 depicts plots of the antenna differential impedance matching (SI 1) as L_Port is varied from 20.0 mm (0.79”) to 45.0 mm (1.77”). It is evident from Figure 15 that the length of the ground plane (L_Port) does not affect the impedance matching of the antenna.

[00135] Accordingly, the innovative antenna the impedance matching of the antenna and its operating frequency are primarily dependent upon the ground plane width (W_Port) with a weak dependency upon ground plane length (L_Port) which provides flexibility in the integration of the antenna into UWB PCBs and UWB devices.

[00136] The antenna radiation efficiency and peak realized gain are depicted in Figures 16 and 17 respectively for an antenna according to the design of Figure 13 with W_Port = 25.0 mm (0.98”) and L_port = 25.0 (0.98”). The antenna peak realized gain remains below 4.0 dB and the radiation efficiency loss remains below 1.0 dB over the frequency range 7.2 GHz to 8.75 GHz. The free space radiation pattern of the innovative differential antenna at 7.5 GHz is depicted in Figure 18. The innovative differential antenna depicted in Figure 13 exhibits good omni-directionality in the ZY and XZ planes. In the XY plane the antenna has a higher gain at +Y orientation.

[00137] 10. BIT SELECTIVE EQUALIZATION

[00138] Within an IR-UWB as described above data symbols are transmitted using a number of UWB impulses within the duration of the data symbol (bit) and the receiver detects the symbols using the received energy that is integrated within a particular time period. However, the energy of the impulse within a time period can leak to the next time period increasing the apparent energy of the next symbol in the next time period. This leakage arising for example from ISI. Accordingly, this leakage can cormpt the next symbol’s reception.

[00139] The inventors have established therefore low complexity decision-feedback equalization (DFE) process. Within the inventive DFE process it is assumed that a portion of the energy detected within a time period will “leak” to the next time period as a result of ISI. This energy may be subtracted from the measured energy in the next period. The remaining energy after the correction being the “true” energy of the next period that should be analyzed to determine its symbol. The portion of the detected energy in a time period to be subtracted from the detected energy in the next time period may be established in dependence upon one or more factors relating to the link including, for example, the data rate, the received energy, RSSI, RNSI, SNR, bit error rate (BER), frame error rate (FER), data within a preamble, or based upon the UWB device employing one or more AI/ML processes to dynamically define this level.

[00140] Within embodiments of the invention the DFE process may be enabled / disabled dynamically during frame reception based upon the IR-UWB dynamically establishing a decision to enable or disable the DFE based upon continuous analysis of received frames, data etc. Optionally, the DFE may be enabled / disabled per frame based upon a decision made during receipt of a preamble within each frame.

[00141] Within embodiments of the invention the DFE may be bit specific, what the inventors refer to as BS-DFE, where the correction by subtraction is only performed when the IR-UWB determines that there is a symbol within a time period, e.g. a “1.” A “0” or no symbol having low received energy has little impact upon the next time period. Within other embodiments of the invention the DFE may be applied to every time period without consideration of the symbol being received.

[00142] Within embodiments of the invention the subtraction may be extended over multiple subsequent time periods with different portions applied to each subsequent time period of the N time periods, where N>1 and is an integer.

[00143] As noted the DFE may be enabled / disabled based upon data rate such that the IR- UWB selectively employs the correction and thereby lowers power consumption when DFE is disabled. Where other factors form the basis of the decision to enable / disable the DFE then the IR-UWB lowers power consumption by selectively switching in/out or on/off an equalizer during reception.

[00144] 11. DUAL IR-UWB

[00145] An IR-UWB such as described and depicted with respect to Figures 1 and 6 and with respect to embodiments of the invention whilst being ultra wideband in frequency of operation relative to other radios supporting other standards typically only cover a portion of the available spectrum permitted within a region. For example, the US FCC allows UWB devices to operate between 3.1 GHz and 10.6 GHz. Accordingly, IR-UWBs whilst operating over wideband are generally unable to support a full 7.5 GHz of operation. Accordingly, if we consider IR-UWBs capable of operating over a 3 GHz region then a first IR-UWB may be designed to support operation over 3 GHz - 6 GHz whilst a second IR-UWB may be designed to support operation over 6 GHz - 9 GHz.

[00146] Accordingly, a device may incorporate multiple IR-UWBs with different operating frequency ranges either to support a single SKU globally or to support increased data rates, reduced latency, and provide / improve channel diversity to enhance multi-path immunity etc. Multiple IR-UWBs thereby supporting multiple input multiple output (MIMO) radio links.

[00147] Within an embodiment of the invention a device incorporates a controller which communicates with N IR-UWBs, where N>2 and is an integer, and establishes M, where 1<M<N and is an integer, links with M other devices incorporating IR-UWBs.

[00148] Accordingly, within an embodiment of the invention the controller (first controller) can dynamically receive data, split the data to N data streams, and couple the N data streams to the N IR-UWBs which are received by another device comprising another controller (second controller) and another N IR-UWBs wherein the received N data streams are combined by the other controller to reconstruct the data. The N IR-UWBs each operate upon different frequency bands.

[00149] For example, consider N=2 where the first IR-UWB supports operation over 3 GHz - 6 GHz whilst the second IR-UWB supports operation over 6 GHz - 9 GHz. The first controller splits the data into 2 streams coupled to the first and second IR-UWBs. In this scenario the effective data rate from the device is increased as it transmits upon both IR-UWBs concurrently and latency of transmission is reduced.

[00150] Within another embodiment of the invention N IR-UWBs each operate within the same band, e.g. 3 GHz - 6 GHz, but each of the IR-UWBs operates upon different channels and/or sub-bands so that there is no interference from one IR-UWB to another. The N IR- UWBs may each support channel hopping according to predefined plans.

[00151] Within another embodiment of the invention the N=2 and the first and second IR- UWBs may operate upon different polarisations such that the device supports polarisation diversity.

[00152] 12. CONCURRENT RANGING - DATA TRANSMISSION

[00153] The inventors have previously established methods for IR-UWBs to implement ranging using UWB pulse bundles as described within WO/ 2019/000,075. These being time of flight (TOF) range finding between a pair of synchronised IR-UWB transceivers, integration time window (ITW) range finding between a pair of unsynchronised IR-UWB transceivers, and a digital signal processing (DSP) TOF exploiting the multiple integration windows within the IR-UWB energy detectors.

[00154] The inventors have extended these concepts so that the IR-UWBs automatically capture ranging information whilst transmitting / receiving data. This being achieved within embodiments of the invention by employing the preamble within each frame to provide the pulse bundles exploited within the ranging protocols. This thereby provides enhanced functionality without an increased overhead by leveraging the common PHY for ranging and data transmission.

[00155] Accordingly, it would be evident to one of skill in the art that an IR-UWB that can concurrently transmit / receive data and range to the other IR-UWB may support additional processing, decision making, functionality.

[00156] Within embodiments of the invention one or more functions of the IR-UWB may be adjusted dynamically in dependence upon the determined range. For example, the IR-UWB may dynamically adjust the data rate in dependence upon the established range or it may dynamically adjust the transmitter output power and/or receiver gain. Within another embodiment of the invention it may adjust a guard band for ISI mitigation.

[00157] The concurrent automatic capture of ranging whilst transmitting / receiving through exploitation of the preamble to provide the pulse bundles employed in the ranging protocols. This allows for reduce latency of ranging but also for an increased rate of ranging measurements as the ranging can be performed at the frame level and for every frame.

[00158] 13. DUAL - MULTIPLE RADIO MODE

[00159] As noted above in section Il a controller may control two or more radios. In addition to the innovative ideas outlined above, then the controller may simultaneously receive frames on N IR-UWBs, N>2 and an integer, then the controller may dynamically select the best IR- UWB to employ using, for example, a cyclic redundancy check (CRC) and link margin. The controller can therefore dynamically select the current best radio to transmit an acknowledged (ACK), next frame, etc. Accordingly, this dual / multiple radio structure allows for reduced processing time by using one radio at a time and changing the current radio on link parameters such as number of lost packets, link margin, RSSI etc.

[00160] Optionally, where N=2 then the antenna of the IR-UWBs may be orientated in order to provide polarisation diversity and/or spatial diversity.

[00161] Now referring to Figure 20 there is depicted a Dual Radio Algorithm (DRA) 2000 according to an embodiment of the invention wherein a controller is employing two IR-UWB transceivers to simultaneously receive wireless transmissions. The received payload is pulled from the IR-UWB showing the best reception quality. If the device also needs to transmit (bidirectional data stream), the transceiver chosen for best reception will be used for transmission. Within this embodiment of the invention the transmission is performed with only 1 transceiver to prevent over-the-air interference. The objective being to widen over-the-air coverage, for both reception and transmission by said device, with 2 antennas (1 per transceiver) offering complementary radiation patterns. Accordingly, DRA 2000 comprises first to fourth Steps 2010 to 2040 respectively, these being:

• First Step 2010 wherein the controller waits to receive 4 frames from each radio

(active and inactive) before progressing to second Step 2020;

• Second Step 2020 where the controller computes normalized RS SI averages of the 4 frames for each radio;

• Third Step 2030 wherein the controller determines if the non-active radio RSSI is greater than the active radio RSSI by 3dB or not wherein upon a negative determination the process loops back to first Step 2010 or upon a positive determination proceeds to fourth Step 2040; and

• Fourth Step 2040 wherein the controller swaps radios so that the non-active radio becomes the active radio and then loops back to first Step 2010.

[00162] DRA 2000 depicts an exemplary embodiment of the invention which may be generalized to N radios, where N>2 and is an integer, and M frames, where M>1 and is an integer.

[00163] Within another embodiment of the invention DRA 2000 the first and second Steps 2010 and 2020, be replaced with an ongoing process wherein a rolling average of the normalized RSSI is being automatically calculated such that the reaction time of transitioning from a non-active radio to active radio through DRA 2000 is reduced.

[00164] Referring to Figure 21 there is depicted a Single Radio Algorithm (SRA) 2100 according to an embodiment of the invention. Accordingly, SRA 2100 comprises first to fourth Steps 2110 to 2140 respectively, these being:

• First Step 2110 wherein the controller waits to receive 4 frames from the active radio before progressing to second Step 2120;

• Second Step 2120 where the controller computes normalized RSSI averages of the 4 frames received; • Third Step 2130 wherein the controller determines if the active radio RSSI is lower than 3dB or not wherein upon a negative determination the process loops back to first Step 2110 or upon a positive determination proceeds to fourth Step 2140; and

• Fourth Step 2140 wherein the controller swaps radios so that the non-active radio becomes the active radio and then loops back to first Step 2110.

[00165] SRA 2100 depicts an exemplary embodiment of the invention which may be generalized to N radios, where N>2 and is an integer, and M frames, where M>1 and is an integer. Where N>2 then the determination of which radio to swap to may be based upon, for example, historical data relating to the performance of the different radios, randomly or a round-robin selection. The RSSI threshold of 3dB within third Step 2130 may be another threshold for the determination of whether to maintain the current radio or not. This threshold may be fixed within some embodiments of the invention or dynamically established within other embodiments of the invention. The dynamic threshold being defined, for example, in dependence upon one or more factors including, for example, RSSI, number of dropped frames, data rate, and a CRC.

[00166] With respect to DRA 2000 and SRA 2100 then an implementation according to an embodiment of the invention may employ within a controller a wireless core (stack) that duplicates the logic required to drive each IR-UWB independently. However, it would be evident that SRA 2100 allows the duplication of logic for the IR-UWB s to be removed as only one IR-UWB is active at any time. SRA 2100 swapping to another IR-UWB when the current active one shows degrading reception quality.

[00167] 14. DYNAMIC PHY RATE SWITCHING

[00168] An IR-UWB such as described and depicted with respect to Figures 1 and 6 and with respect to embodiments of the invention supports dynamic data rate adjustment without requiring a re-locking of a phase locked loop (PUU). Within an IR-UWB according to an embodiment of the invention the pulse repetition rate (PRR) of the pulses is determined by the clock signal frequency and the period of the data signal determines the data rate. As the data rate adjusts then the IR-UWB transmitter generates a number of pulses per bit in dependence upon the PRR and the length of the data signal high time. No other configuration of the IR- UWB transmitter is adjusted as the data rate is varied. Accordingly, an IR-UWB transmitter according to an embodiment of the invention can change from one data rate to a second data rate simply based upon the external controller simply changing the data rate provided to the IR-UWB. [00169] The switch from one data rate to another can be made from one frame to another or between the header of the frame and the payload of the frame as no reconfiguration of the IR- UWB transmitter is required. As evident from Figure 6 an IR-UWB according to embodiments of the invention employs the same underlying clock generation methodology wherein the 20MHz clock is generated for both the transmit and receive chains from the same 32kHz low- frequency crystal oscillator 615. A “reset switch” within the IR-UWB is employed to control the integration windows of the energy detection portion of the IR-UWB receiver and is held open only during the actual integration. The reset switch being controlled via a SYNC control signal. Accordingly, the IR-UWB receiver by adjusting this SYNC control signal can dynamically adjust the length of the integration windows and accordingly dynamically adjust the receiver for different data rates.

[00170] Within an embodiment of the invention the PHY header can include data relating to data rate such that the receiver can adjust the integration window duration through the SYNC control, for example.

[00171] As the adjustment of the data rate of the IR-UWB transmitter is essentially automatic based upon the data received and receiver adjusted based upon a control signal, a dynamic adjustment of the PHY can be undertaken with low latency. With a PHY header incorporating data relating to PHY information then not only can the data rate be adjusted but other PHY aspects dynamically adjusted according to a metric of a combination of metrics. For example, dynamically changing the PHY whilst a link is active may include, for example, dynamically changing data rate, modulation, forward error correction (FEC), and output power. The metric or combination of metrics may be selected, for example, from link budget, packet error rate (PER), and “Listen before talk” or CCA results.

[00172] Accordingly, dynamic adjustment of the PHY can be undertaken with low latency to address bursty traffic, ISI etc.

[00173] 15. AUTOMATIC ANTENNA DIVERSITY

[00174] Within some wireless applications and scenarios polarisation diversity, spatial diversity or radiation pattern diversity can beneficially address or mitigate aspects of a link environment impacting link performance. Accordingly, a pair of antennas are employed, which are coupled to the same IR-UWB transmitter chain. Within polarisation diversity the two antennas, one for each polarisation, overlap spatially whilst within spatial diversity the two antennas, generally the same polarisation, have different spatial radiation patterns.

[00175] However, where there is a requirement for selective drive one antenna, the other antenna or both antenna concurrently then the antenna circuit driving the polarisation diverse or spatial diverse antenna pairs employs a Balun, which allow for the balanced and unbalanced lines of the IR-UWB transmitter and antenna to be interfaced without disturbing the impedance arrangement of either line, with a routing switch to couple the output of the Balun to one antenna or another or to both.

[00176] However, the inventors have established an alternative design wherein the output amplifier is replaced with a differential low noise amplifier (LNA) and a pair of open/closed 1:1 (e.g. PIN) switches thereby removing the requirement of the Balun / routing switch. Accordingly, the differential output signals of the IR-UWB transmit chain, referred to as RFN and RFP, are coupled to the input of the differential LNA via the two PIN switches, or other switching elements providing simple 1:1 functionality, then the circuit provides for three operating modes:

• Mode 1 : Only the RFN output is amplified whilst the RFP path is turned off;

• Mode 2: Only the RFP output is amplified and RFN path is turned off; and

• Mode 3: Both the RFN and RFP outputs are amplified.

[00177] Using a pair of antennas (differential antenna), each coupled to an output port of the differential LNA the circuit provides programmable antenna diversity. Using a differential antenna with the proposed technique provides for switchable polarisation diversity and/or spatial diversity and/or radiation pattern diversity. The determination of which mode to operate in may be made by a controller in dependence upon one or more factors relating to a link the IR-UWB transmitter forms part of.

[00178] 16. TRISTATE ANTENNA DIVERSITY

[00179] As noted in section 15 polarisation diversity, spatial diversity or radiation pattern diversity can beneficially address or mitigate aspects of a link environment impacting link performance. Within section 15 the diversity was described from the perspective of a transmitter forming part of an IR-UWB. However, these benefits of polarisation diversity, spatial diversity or radiation pattern diversity can relate to the receiver forming part of an IR- UWB.

[00180] Within Figures 4 and 5 a LNA 420 or LNA 520 is employed to amplify the received signal. Within embodiments of the invention the inventors have established IR-UWBs, such as the SRI 010 and SR 1020, which have differential input ports, RFN and RFP, which are coupled to the subsequent receiver chain / energy detection circuitry and subsequent digital circuits etc. Accordingly, a differential LNA is employed as part of the front end of the IR-UWB. This, rather than being connected to a single differential antenna, may be coupled to a pair of antennas and provides what the inventors refer to as tristate antenna diversity. The pair of antennas may be different polarisations, cover different spatial regions or have different radiation patterns. By disposing a pair of open/closed switches (e.g. PIN switches) between the RFN and RFP ports and the differential LNA then three modes of tristate antenna diversity are supported:

• Mode 1 : Only the signal coupled to the RFN port is amplified and signal coupled to the RFP path is turned off (blocked);

• Mode 2: Only the signal coupled to the RFP port is amplified and signal coupled to the RFN path is turned off (blocked);

• Mode 3: The differential signals coupled to both the RFN and RFP ports are amplified.

[00181] Depending on particular configuration of the pair of antennas, i.e. different polarisations, different spatial regions, different radiation patterns, and other aspects such as the over-the-air signal properties, direction, polarisation etc. then the power coupled to one of the RFN, RFP, or the pair of RFN-RFP ports may be higher than the other two cases. Accordingly, the IR-UWB may execute an antenna-diversity selection algorithm upon establishing the link or periodically, aperiodically, or during the receipt of a header of a frame in order to establish which of the three modes has the highest received power and configure the IR-UWB accordingly.

[00182] 17. CONCURRENT OPERATION

[00183] Concurrent operation of multiple radios within the prior art is typically not allowed by the communications architecture and protocol. Within the prior art with respect to UWB radios then typical methods are based upon beacons transmitted by each device and associating pre-determined timeslots to each device, see for example such as US7454218. Whilst US7454218 does allow for band hopping all devices move as one. Accordingly, prior art UWB protocols are essentially direct extensions of other wireless protocols into the UWB space.

[00184] However, with many of the anticipated of UWB radios within many applications the density of devices can be large and the number of concurrent systems similarly large such that the management overhead would be significant limiting either the number of devices or the timeslots accessible. Accordingly, the inventors have established processes relating to concurrent operation of IR-UWB radios with minimal overhead and without centralized network control. [00185] Within section 6 a method I process of “Listen Before Talk” is outlined wherein an IR-UWB radio can verify if a channel is available and start using it immediately. Within this section the inventors have extended this to reduce the probability of collision between IR-UWB radios. This process described and depicted with respect to Figure 22 adds a predefined delay or random delay to the IR-UWB transmitter schedule to reduce the probability of collision(s). [00186] This can be applied to radios operating upon fixed channels as well as radios using frequency hopping. In a similar manner the inventors also consider that different radios will configure to different frequency hopping patterns that may be predefined or random to similarly reduce the probability of collision. The inventors within PCT/CA2020/000031 established the concept of sub-bands within an operating bandwidth of an IR-UWB radio or the UWB spectrum and that an IR-UWB radio may transmit sequentially in a predefined sequence of sub-bands. These sub-bands may have common bandwidth or different bandwidths and the number of sub-bands may vary within different systems as may the bandwidth(s) or portion of UWB spectrum occupied. The sequence of bands for the IR-UWB radio being defined either in dependence upon a configuration setting provided to the IR-UWB radio or through a spectrum sensing process.

[00187] However, PCT/CA2020/000031 is silent to concurrent operation between multiple IR-UWB radios within a region. Within PCT/CA2020/000031 an embodiment of the invention assumed the frequency range to be that of the FCC as defined by the lower and upper limits of 3.1 GHz and 10.6GHz, namely 7.5 GHz, and a 500 MHz sub-band is assumed so that there are 15 bands, namely Bands I, II, III. . .XIV and XV. The number of bands, their bandwidths, the total frequency etc. may vary without departing from the scope of the invention. The number of sub-bands within a cyclic pattern may be 2, 3, 4 or more. Then as per PCT/CA2020/000031 each radio has a cyclic hop sequence of 5 sub-bands. Some radios will run I, II, III, IV, V; others VI, VII, VIII, IX, X; and so on. The determination of the hop sequence (hop pattern) for each radio may be based upon a configuration setting provided to the IR-UWB radio, through a spectrum sensing process, or through a pseudo-random selection of a sequence from sequences stored by the radio, for example.

[00188] If we consider those that are configured to run I, II, III, IV, V then some may start at I, others II, and so on. The determination of where in a selected hop pattern the radio starts its hop sequence may similarly be based upon a configuration setting provided to the IR-UWB radio, through a spectrum sensing process, or through a pseudo-random selection of a sequence from sequences stored by the radio, for example. Other radios may run other non-sequential sequences.

- 1 - [00189] However, as the number of devices increases then the probability of collision increases. Accordingly, the inventors established the process described and depicted with respect to Figure 22 to further reduce the probability of collision(s). Referring to Figure 22 Algorithm 2200 comprises first to fifth Steps 2210 to 2250, these being:

• First Step 2210 - “Set Frequency Band” where the IR-UWB selects the frequency band of operation;

• Second Step 2220 - “Add Delay” where a predefined or pseudo-random delay is added to reduce a probability of link synchronizations failure;

• Third Step 2230 - “Listen Before Talk” where the “Listen Before Talk” algorithm of Figure 19 is executed;

• Fourth Step 2240 - “Tx Abort?” wherein if the transmit process is aborted as a result of the “Listen Before Talk” of third Step 2230 the process loops to first Step 2210 and the IR- UWB retries at a different band otherwise the process proceeds to fifth Step 2250; and

• Fifth Step 2250 where in the frame is transmitted.

[00190] Within first Step 2210 the frequency band setting may be according to a pseudorandom determination, for example, or a pseudo-random point within a sequence, or a pseudorandom point within a pseudo-random sequence for example to reduce the probability of collision. Further, integrity of the data transmission is provided by allocating (dedicating) a percentage of the total channel to retransmissions. It would be evident that the process defined by Algorithm 2200 may be applied to the sub-band hopping processes described above without departing from the scope of the invention.

[00191] 18. DYNAMIC AUDIO AND FALLBACK

[00192] Amongst the applications of IR-UWB devices transmitting or streaming audio content is one. Within the prior art audio content is transmitted in compressed form through audio coders/decoders (codecs) where these are present or in uncompressed form. Whilst in some applications such as security monitoring, environmental monitoring etc. latency is not a significant issue for audio content being rendered to a user it is. Accordingly, it may be beneficial in such instances to dynamically swap between compressed and uncompressed formats in order to manage the volume of data transmitted versus the latency in the compression/decompression. It may also be beneficial to dynamically adjust the degree or level of compression applied in dependence upon the link / channel conditions.

[00193] Accordingly, the inventors have established processes for either dynamically switching between uncompressed and compressed audio or adjusting the extent of encoding employed. The switching being undertaken whilst maintaining the integrity of the audio at low latency (below 10 ms) and achieving imperceptible transitions to a user. An exemplary process is depicted in Figure 23 by Flow 2300 comprising first to fifth Steps 2310 to 2350 respectively. Flow 2300 may be applied to upstream and downstream audio transmission although as will be evident with respect to Figures 24 to 26 the “fallback” from one transmission state (uncompressed) to another (compressed) may be enabled discretely for either the upstream and downstream or that different fallback processes may be applied for example to the upstream. Accordingly, with respect to Flow 2300 these steps comprise:

• First Step 2310 wherein initial uncompressed audio is split to fit the pay load of the wireless link (channel);

• Second Step 2320 wherein a determination is made as to whether a fallback has been enabled or not and upon a positive determination the process proceeds to fourth Step 2340 otherwise it proceeds to third Step 2330;

• Third step 2330 wherein the split uncompressed audio is transmitted;

• Fourth Step 2340 wherein the split uncompressed audio is compressed; and

• Fifth Step 2350 the compressed audio is transmitted.

[00194] The dynamic encoding also allows for reduced power consumption as the codec is unpowered if it is not required. As the determination of whether to enable or disable fallback on each of the upstream and downstream can be performed per frame there is time to enact the necessary power up of the codec when required prior to the next frame. Fallback may be triggered differently for upstream and downstream as for example, downstream may be continuous streaming audio whilst upstream is sporadic content or nothing.

[00195] A determination on the fallback may be made as outlined below in respect of Figures 24 to 26 or it may be based upon one or more other factors including, but not limited to, buffer size, PER, RSSI, Listen Before Talk results, whether dummy frames are being transmitted etc. With respect to Figures 24 to 26 the determination of enabling fallback is based upon the downstream link performance (as typically downstream audio content dominates many applications such as streaming audio, video, gaming etc.) however it would be evident that fallback may be determined for the upstream in other applications.

[00196] Now referring to Figure 24 there is presented a Flow 2400 with respect to the determination of whether to enable fallback on the downstream. Flow 2400 comprising first to fifth Steps 2410 to 2450, these being: • First Step 2410 wherein a link is established with a currently selected transmission mode.

• Second Step 2420 wherein a frame is transmitted according to the current mode and predefined concurrency mechanism. This transmission may be successful or not.

• Third Step 2430 wherein a value relating to the size of the transmission (Tx) queue is established. Unsuccessful transmissions will lead to an increase of this value.

• Fourth Step 2440 wherein it is determined if the value relating to the size of the Tx queue is above a predefined threshold. This threshold value may be selected to optimize the speed of the algorithm, meet the latency requirement etc. whilst avoiding false trigger. Upon a determination that the value is not above the predetermined threshold the process proceeds to loop back to second Step 2420 otherwise it proceeds to fifth Step 2540.

• Fifth Step 2450 wherein having determined that the value relating to the size of the

Tx queue is above a predefined threshold the fallback flag / trigger is set to ON.

[00197] Now referring to Figure 25 there is presented a Flow 2500 with respect to the determination of whether to disable fallback on the downstream. Flow 2500 comprising first to fifth Steps 2510 to 2550 respectively, these being:

• First Step 2510 wherein a link is established with a currently selected transmission mode.

• Second Step 2520 wherein a frame is transmitted according to the current mode and predefined concurrency mechanism. This transmission may be successful or not.

• Third Step 2530 wherein the current values of the Uink Margin and CCA are established.

• Fourth Step 2540 wherein determinations are made as to whether both the Uink

Margin is above a predetermined threshold and the CCA is below another predefined threshold wherein upon determination that both conditions are met the process proceeds to fifth Step 2540 otherwise the process loops back to second Step 2520.

• Fifth Step 2550 where based upon the determination that both the Uink Margin is above a predetermined threshold and the CCA is below another predefined threshold the fallback flag / trigger is set to OFF. [00198] Within Flow 2500 an average over N frames, N>2 and a positive integer, for the link Margin and CCA values may be employed in order to reduce the risk of a false decision to set the fallback flag / trigger to OFF.

[00199] Now referring to Figure 26 there is presented a Flow 2600 with respect to the determination of whether to disable fallback on the downstream. Flow 2600 comprising first to seventh Steps 2610 to 2670, these being:

• First Step 2610 wherein a link is established with a currently selected transmission mode.

• Second Step 2620 wherein a dummy frame is transmitted in one of the retransmission timeslots on a channel, channel N, is made when the retransmission timeslot is not required.

• Third Step 2630 wherein a determination is made whether the dummy frame transmission was successful and upon a positive determination the process proceeds to fifth Step 2650 otherwise it proceeds to fourth Step 2640.

• Fourth Step 2640 wherein the process executes a “long wait” upon an unsuccessful transmission and returns to second Step 2620 later to verify if the channel is now clear.

• Fifth Step 2650 wherein as determination is made as to whether all channels have been established as clear wherein if all channels are verified as clear then the process proceeds to seventh Step 2670 otherwise it proceeds to sixth Step 2660.

• Sixth Step 2660 wherein a “short wait” is undertaken where the channel to be transmitted upon for the dummy frame is changed and the process waits until the next retransmission timeslot is available in order to return to second Step 2620 and now transmit upon the next channel.

• Seventh Step 2670 wherein if all channels have been verified as clear then the fallback flag / trigger is set to OFF.

[00200] Whilst Flow 2600 is described as performing the process until all channels are complete the IR_UWB will have a setting defining the number of channels etc. As such the number of channels may be one or it may be more. Within other embodiments of the invention the number of channels may be a subset of all channels the IR-UWB can transmit upon. Within other embodiments of the invention the flows presented in Figures 24 to 26 a channel may be a sub-band such as described above. [00201] Whilst the processes described and depicted with respect to Figure 23 and Figures 24-26 have been described with respect to transmitting compressed or uncompressed content based upon a determination to fallback from uncompressed to compressed it would be evident that multiple decision thresholds may be established such that the fallback may be from uncompressed to one level of compression of a series of levels of compression.

[00202] Whilst the processes described and depicted with respect to Flow 2300 in Figure 23 and Flows 2400, 2500 and 2600 in Figures 24-26 have been presented in respect of audio it would be evident that the processes are applicable to the downloading of any content, namely, audio, video, data, etc. where encoding of the content varies based upon the link performance and can be dynamically enabled / disabled. The emphasis in the inventors determination of processes is presented with respect to audio as this typically has the lowest threshold of perception in respect of latency / quality for users.

[00203] Within embodiments of the invention the fallback enable / disable processes employ input qualities to dynamically either enable compression, dynamically disable compression or adjust a level of compression employed in transmitting the content. However, within other embodiments of the invention the fallback may be another aspect of the data transmission process other than compression. For example, the fallback may be a change to the data rate or one or other PHY parameters, such as symbol rate, modulation format, output power, etc. Within other embodiments of the invention the parameters monitored may be varied or added to such as monitoring frame collisions or link budget breakdowns etc. to make adjustments in real-time to maintain the link active or active with lowest latency or active with maximum data throughput etc. Metrics may include, but not be limited to, PER, RSSI, RNSI, Listen Before Talk results, number of “Dummy Frames” successfully transmitted, Listen Before Talk retries or CCA value. Within other embodiments of the invention the adjustment may be increase range, improve ranging accuracy, link margin etc.

[00204] Within embodiments of the invention the thresholds to enable fallback and disable fallback may be different so that there is “hysteresis” in the process after the fallback is enabled and the process returns to normal and disables the fallback.

[00205] Within the preceding description with respect to Figures 23 to 26 the fallback technique has been presented with respect to audio applications only. However, the inventors has established that the same methods and processes may be employed to implement fallback for other data transmissions of electronic content as well as electronic data being communicated between electronic devices. For example, the users have demonstrated introducing fallback for communications between a computer mouse and another electronic device. Within embodiments of the invention different metrics may be employed and/or combined to develop an ultra-fast fallback mechanism relying on Clear Channel Assessment results.

[00206] Accordingly, embodiments of the invention address limitations within the prior art by:

• using Clear Channel Assessment (CCA) results as a metric to enter a fallback mode;

• combining CCA with one or more other metrics to trigger entry into a fallback mode, such metrics may include, but not be limited to, PER, RSSI, RNSI, Listen Before Talk results, and Dummy Frames;

• an application data-rate is dynamically adjusted in real-time according to the CCA results; and

• employing fallback to increase concurrency using dummy frames transmissions to sense channel availability to return to normal.

[00207] Within the following description as part of Section 18, Dynamic Audio and Fallback, an exemplary scenario of the fallback mechanism to a computer peripheral, specifically what the inventors refer to as an “8k gaming mouse.” The parameters of this exemplary embodiment being:

Table 2: Data Rate and Parameters of “8k Gaming Mouse”

[00208] FALLBACK_TXQ_MAX_SIZE (85): Maximum Tx queue length. If the Tx queue reaches this value, it means the link is disconnected and that the mouse will immediately switch to Fallback 2 (FB2). This threshold is less than the actual maximum size of the Tx queue (90), due to the fact that when the queue is full, a flush is done for each send attempt. This causes the queue threshold to never quite reach its maximum length.

[00209] FALLBACK_TXQ_THRESHOLD (33): Along with CCA Try Count, it used to determine when to return from fallback based on the Tx queue length. The value here is xlO the desired threshold. [00210] TXQ_FALLBACK1_TRIGGER_THRESHOLD (30): Along with

CCA_TX_FAIL_THRESHOLD, it is used to determine when to into the first fallback level based on the Tx queue load.

[00211] TXQ_FALLBACK2_TRIGGER_THRESHOLD (60): Along with

CCA_TX_FAIL_THRESHOLD, it is used to determine when to into the second fallback level based on the Tx queue load.

[00212] CCA_TX_FAIL_THRESHOLD (5): Used to determine when to go into fallback. This value is compared to a running average of (Tx Fail Values x 10). The TXQ_FAEEB ACK1/2_TRIGGER_THRESHOED must also be met at the same time to trigger a fallback.

[00213] CCA_RATIO_SWITCH_BACK_THRESHOED (25): Along with

FAEEBACK_TXQ_THRESHOED, it is used to determine when to return from fallback based on the try count. This is the percentage of the maximum number of CCA Try attempts under which the link is considered good.

[00214] Fallback Update Rate: A fallback module is updated at every connection Tx event (success, fail and packet dropped). The cca tx fail metric, used to determine when to trigger fallback, is processed at every Tx event. Other metrics are processed at a nominal 250ms rate, more precisely at (max_packets_per_second/4). This implies that for these metrics, the 250ms updates may go beyond 0.25s if the Tx rate is below the maximum.

[00215] Fallback Trigger Mechanism: Fallback is triggered based on the cca_tx_fail_count and tx_queue_load. cca_tx_fail_count is incremented whenever AEE of the cca trys have failed in a given timeslot. tx_queue_load mirrors the number of packets that are queued for transmission and it increases when the link throughput is insufficient.

[00216] Within an exemplary embodiment of the invention there are 4 elements in the cca tx fail array and a running average is calculated at every Tx event. At every Tx event, the cca_tx_fail_count either incremented by 1 or not at all. The values are multiplied by 10 for the purpose of determining the threshold.

[00217] For example, when the 4 elements of the CCA TX FAIE running average array are (0, 1, 0 and 0) then the average is calculated as (0 + 10 + 0 + 0) / 4 = 2.5 or 2. Accordingly, in this the average is 2 and below the CCA_TX_FAIE_THRESHOED of 5 which is calculated using the array (1, 0, 0, 1) and thereby average = (10 + 0 + 0 + 10) / 4 = 5.

[00218] Here the average has reached the threshold and will thus trigger a switch to the first fallback level, Fallback 1, if the tx_queue_load is also > 30. Otherwise, we consider the link to be in a good condition and the process stays within the normal mode. Note that when in 8k mode, FBI and FB2 correspond to the 4k mode. When in 4k mode, FBI corresponds to 2k rate and FB2 corresponds to Ik rate.

[00219] Accordingly, fallback proceed through the following levels of Normal(8k)- >Normal(4k)-> FBI -> FB2. This being depicted in Figure 27.

[00220] Fallback Return Mechanism: The return from fallback is based on 2 metrics which are sampled every 250mS and if they are below their respective thresholds, their count is incremented up to a maximum count representing 15 seconds, or 15 * 4 = 60. If during the sampling time a metric is below the threshold, the count is reset. Thus, the metric must have passed the threshold continuously for about 15 seconds.

[00221] Only when both metrics have passed is a return from fallback triggered. Fallback return steps through the levels: FB2 -> (15 seconds) -> FBI -> (15 seconds) -> Normal (4k). It should be notes that this fallback mechanism will not recover the 8k mode; it will stop at 4k.

[00222] CCA Try Fail Count: The cca_try_fail_count is incremented every time a cca try has failed. The CCA_RATIO_SWITCH_BACK_THRESHOLD is a percentage of the maximum number of cca trys under which the link is considered good. The maximum number of cca trys in every sampling interval is given by Equation (2).

(Data Rate(8k, 4k, 2k or Ik) * CCA_try_count) 14 (2)

[00223] Accordingly, with this example, at 4k, the maximum number of try counts is (4000 * 2) = 8000. So, a threshold of 25 (%) means that when the try count falls below 2000/second for 15 seconds, this metric is considered good.

[00224] TX Queue Len: The TX Queue Len is calculated from a running average array of 3 elements, similar to the CCA TX FAIL running average array. This value is xlO the actual tx queue len. Based on the FALLBACK_TXQ_THRESHOLD of 33, the tx queue len must be below 3.3 for 15 seconds for the metric to be considered good. It should be noted that the Tx queue load used for triggering fallback is an instantaneous value, unlink the averaged value used for recovery.

[00225] It should be noted that whenever there is a switch to/from fallback within this example a sequence is performed wherein all metrics are cleared, the fallback module enters a wait period of 5 Tx events before resuming metric processing in order to allow the link to stabilize, and the application re-initializes certain fallback parameters due to a change, such as data rate.

[00226] 19. AVERAGING RECEIVED UWB IMPULSE ENERGY TO IMPROVE THE SENSITIVITY [00227] As outlined above within an IR-UWB data symbols are transmitted using a series of UWB impulses and the receiver detects the symbols using an energy detector which integrates the received power within each time period (integration window) of a series of time periods (integration windows). Within an embodiment of the invention a symbol may be sent multiple times and the detected energies within their corresponding time periods are averaged in order to improve the signal detection accuracy. However, unlike averaging of the actual signal within coherent radio systems this innovative technique averages the output of the integrator(s) that calculates the received energy within the symbol period. Accordingly, the innovative process performs at a lower clock frequency (the symbol frequency).

[00228] 20. FREQUENCY OFFSET

[00229] Within an IR-UWB transmitter or transceiver as described and depicted within this specification a symbol is transmitted as a series of pulses where each pulse is at a predetermined frequency. At the IR-UWB receiver, as depicted in Figure 5, the received amplified pulses (received amplified signal) are initially provided to a first squaring mixer (MIX1) 540 which multiplies the received amplified signal with itself where the resulting IF signal, after further amplification (which also implements a bandpass filter function), is then coupled to a second squaring mixer (MIX2) 560 which down-converts the IF signal to a baseband (BB) signal at BB frequency. The baseband frequency converted signal is then coupled to the energy detection circuit 580.

[00230] Accordingly, the IR-UWB receiver by self-mixing generates IF and BB without requiring knowledge of the received signal a-priori. The bandpass filter function of the amplifiers between the IF and BB stages however gives the receiver in essence a center frequency. Accordingly, what the inventors refer to as a sphere of influence (SOI) between the transmitter and receiver can be controlled by using an “offset” in frequency between the transmitter (TX) and receiver (RX).

[00231] Accordingly, this SOI can be adjusted precisely by increasing or decreasing the effective frequency offset between TX and RX (what the inventors refer to as transmitter offset). This SOI control affects the link budget and is achieved through digital control of the center pulse frequency of the transmitted pulses. As evident from the embodiments of the invention described within this specification the IR-UWB transmitter by virtue of “frequency hopping” to generate the pulses at different frequencies already supports digital control of the transmitter frequency. All that is required is to provide increased resolution in the digital setting to offset the frequency slightly rather than hop a significant offset away. [00232] The fine control of this transmitter offset allows for improvements to be made with respect to the coexistence of multiple links in a constrained space by either reducing the SOI to a minimum SOI needed for a given link or reducing the number of received reflections that impact performance due to multi-path effects.

[00233] Within embodiments of the invention the transmitter offset may be employed within a dynamic loop that can modify the SOI in real time to increase or decrease the SOI as needed a link. This being possible through the IR-UWB devices described within the specification supporting frequency changing (i.e. sub-band to sub-band or the frequencies within symbols or RX allocation) at the frame by frame level.

[00234] This transmit offset can be used in the context of a frequency hopping sequence with a built in transmit offset between TX and RX frequency or within a single frequency link with a frequency offset. As noted the transmitter offset, offset, can be pre-configured or dynamically established.

[00235] 21. ANTENNA POSITIONING FROM RANGING INFORMATION

[00236] As described above UWB devices and processes / algorithms employed by UWB devices according to embodiments of the invention may be employed in providing ranging functionality to determine the distance between two radios using time of flight (ToF). The accuracy of the measurement is, however, reduced by multipath propagation. Multipath propagation becomes the dominant transmission path when the polarizations of the antenna are orthogonal. Within the embodiment of the invention presented here the inventors employ the ranging information to determine if the antennas are properly polarized with respect to one another, e.g. aligned. If the distance between the device is known then the value of the ranging provides information as to whether the direct path propagation or the multipath propagation was used to transfer the information. If multipath propagation was used then the two antennas were not properly aligned.

[00237] Accordingly, this embodiment of the invention addresses limitations within the prior art by providing an antenna displacement detection technique based on ToF ranging. For example, consider the scenario of a wireless dongle for a peripheral, e.g. gaming mouse. Accordingly, where the dongle and peripheral each include an ultra wideband transceiver according to an embodiment of the invention then a time of flight (ToF) feature may be employed to establish the dongle’s antenna position relative the mouse’s when the user initializes the setup. Within an embodiment of the invention a user may via a user interface enter the distance between the dongle and the mouse. If this is below a given threshold L_THD, e.g. L_THD = 2 meters, then ToF ranging may be bypassed as there should be no connection problem even in the case of antenna cross-polarization. Otherwise, a ToF ranging sequence is triggered to measure the distance between dongle and mouse, d_T0F is initiated. If the latter is not within an accepted error margin, M_THD, the system establishes that the mouse and the dongle are not properly positioned and that their antennas are probably misplaced. The user is then prompted to properly position the antennas and once that is done, another ToF ranging is initiated. Referring to first and second Graphs 2800 and 2850 in Figure 28 it is evident that the ToF ranging sequence with cross-polarized antennas (second Graph 2850) would render a distance measurement which is considerably higher than the actual distance (aligned antennas in first Graph 2800).

[00238] Referring to Figure 29 there is depicted a Flowchart 2900 that describes a logic flow for such a system according to an embodiment of the invention.

[00239] Within another embodiment of the invention an initialization may be one wherein the dongle and mouse are adjacent to one another and the system knows that initially d_T0F < L_THD . Accordingly, ToF ranging may be combined with other metrics such as RSSI to establish cross- polarization of the antennas as the measured RSSI reduction may not agree with that predicted based upon the ToF ranging measurement.

[00240] 22. LISTEN BEFORE SYNC

[00241] Time Division Multiplexing Access (TDMA) is a technique used in telecommunications to allow multiple users to share the same frequency channel by dividing a predefined time frame into multiple time slots. In prior art systems, each user is assigned a specific time slot within the predefined time frame within which to transmit independent of whether or not other users transmit in their time slots. However, this fixed, predetermined time slot assignment can consume significant resources, e.g. time and power, that may not be available in low-power and/or low-latency systems.

[00242] In order to address this the inventors have established a method to improve upon the prior art by establishing the starting time of a device rather than it being predefined. Within an embodiment of the invention the inventors process employs Listen Before Talk during an interval of time consisting of multiple timeslots. The number of listen to time slots may be fixed or it may be adjusted dynamically. While listening, the UWB device records any moments that is or are transmissions on the channel. Once the listening period is completed the starting position for transmissions of that UWB device can be determined in order to reduce the likelihood of collision. [00243] Embodiments of the invention address limitations within the prior art by employing CCA to determine an initial transmit schedule for a UWB device and subsequently to determine whether schedule adjustments are required. Within other embodiments of the invention this determination may be combined with a Distributed Desync algorithm / process, as presented below in Section 23, and/or a Listen Before Talk algorithm / process, as presented above in Section 6.

[00244] Within a UWB transceiver (UWB radio) a clear channel assessment (CCA) may established by CCA sensing, for example, every 5 ps, wherein once the UWB radio detects another UWB radio (hereinafter an aggressor) the UWB radio begins to probe the network every 2.5 ps non-stop until the aggressor is no longer detected. The timings presented within this specification are examples only and the specific timing etc. dependent upon the UWB radio. Within Figure 30 detection of an aggressor is displayed by a toggle DETECT where SO shows the actual Rx of the CCA checks. The threshold used was 25. Figure 30 depicts the results obtained by an embodiment of the invention for an aggressor employing inverted on- off keying (IOOK) with long frames. The inventors have demonstrated good detection results for other scenarios including an IOOK aggressor with short frame results (good precision and the beginning of the frame is not missed), 2-bit pulse-position modulation (PPM) long frames and 2-bit PPM short frames.

[00245] Accordingly, the inventors have established a link power up time finding algorithm comprising the following steps for an exemplary UWB radio with OOK:

• Translate a 1 ms schedule window into a bit vector, each bit representing on or off for an increment of 2.5 us;

• Translate the 1 ms schedule detected through CCA sensing into a bit vector, each bit representing on or off for an increment of 2.5 us (transmission time may be increased by a configurable factor to provide a safety margin);

• Bit shift one of the schedules until all possible superpositions are done (1ms / 2.5 us = 400 bit shifts) and for each bit vector superposition performing an exclusive OR (XOR) between the bit vectors, counting the number of ones in the resulting vector and computing a maximum;

• Register the offset for which the number of ones was maximum; and

• Whilst CCA sensing starting the link at the exact time corresponding to the registered offset.

[00246] For example, consider the following. UWB Radio Schedule: 000000001111000000001111

Sensed Schedule: 000000001111000000001111

[00247] If we shift the sensed schedule right, let’s look at a few offsets:

[00248] Offset 0 (NOT OPTIMAL):

UWB Radio Schedule: 000000001111000000001111

Sensed schedule: 000000001111000000001111

Xor: 000000000000000000000000

One count: 0

[00249] Offset 1 (NOT OPTIMAL):

UWB Radio Schedule: 000000001111000000001111

Sensed schedule: 100000000111100000000111

Xor: 100000001000100000001000

One count: 4

[00250] Offset 2 (NOT OPTIMAL):

UWB Radio Schedule: 000000001111000000001111

Sensed schedule: 110000000011110000000011

Xor: 110000001100110000001100

One count: 8

[00251] Offset 3 (NOT OPTIMAL):

UWB Radio Schedule: 000000001111000000001111

Sensed schedule: 111000000001111000000001

Xor: 111000001110111000001110

One count: 12

[00252] Offset 4 (OPTIMAL):

UWB Radio Schedule: 000000001111000000001111

Sensed schedule: 111100000000111100000000

Xor: 111100001111111100001111

One count: 16

[00253] Accordingly, it is event that the optimal offset results in a maximum number of ones on the XOR bit vector or a minimum number of ones by performing an AND operation on the resulting vectors.

[00254] Within this section the link power up time finding algorithm implementation and test description are presented. The algorithm assumes a periodicity over 1ms for any aggressor’s schedule and the UWB radio’s schedule, Granularity of the CCA sensing is 10 ps, the UWB radio is represented as 100 ps on and 150 ps off, repeated 4 times for a total of 1 ms. The reality is about 95 pus on and 155 ps off. The total delay added for performing the sensing and algorithm being about 4 ms.

[00255] GPIOs were implemented to validate the different steps of the algorithm, the different validation steps are shown in the following figure. These upon the test instrumentation were identified between colored flags which are numbered in the plots presented with Figure 31 by numbers representing the step where:

• Step 0 consists of CCA sensing every 10 us, the trace shows the on/off states that are registered in a table inside the firmware (FW);

• Step 1 consists of displaying the registered sense schedule state for the aggressor on the trace and for the UWB radio (our) schedule on its trace; and

• Step 2 consists in showing the offset selected by the algorithm on the trace; and

• Step 3 where the offset between the actual radio transmission between the aggressor and our device is shown.

[00256] STEP 0: Presented by Figure 32 wherein it is evident on trace D15 that the aggressor transmissions (D4) was detected properly. The time measured for the total sensing is exactly 1 ms. The detected airtime of the aggressor is 103 ps.

[00257] STEP 1 : Presented in Figure 33 where the representation of the sensed schedule and our schedule inside the FW tables are on traces D14 and DI 5. This will be the startup synchronization between the signals if no algorithmic intervention is performed. We can see on trace DI 5 that our schedule is about to start just after the aggressor schedule (DI 4) where the algorithm should correct that.

[00258] STEP 2: Presented in Figure 34 where the the number of pulses on D13 minus 1 represents the offset chosen by the algorithm, it is equal to 10. As seen on step 0, the detected airtime of the aggressor is 103 us. As seen on step 1, our schedule was about to start just after the aggressor's schedule. Therefore, our schedule should be delayed by almost the totality of the 103 ps aggressor airtime. Hence an offset of 10 was chosen because 10 * 10 ps = 100 ps. (10 ps being our radio’s granularity)

[00259] STEP 3: Presented in Figure 35 where it is evident that the delay between the end of the aggressor transmission (D4 going high), and the start of our schedule transmission (DI 2 going low) is equal to 14 ps. We know that the actual transmission started about 6 ps before that (preamble and sync word are not shown on IDLE pin). So our transmission started exactly 8 ps after the end of the aggressor transmission, as expected the first transmission was delayed by 100 ps.

[00260] The results described in the preceding steps is the definition of success used in the next portion of this section. It would be evident that if no collision is detected between the aggressor and our schedule, no intervention is done and the schedules will be interleaved in a random manner.

[00261] Figure 36 depicts results of link power up time finding algorithm repeatability and consistency tests (based upon single band schedule/sensing) where a sweep of attenuation in steps of 5 dB was performed with the threshold set to 25. For each attenuation step, the test described above was performed 10 times. The number of successful results is noted in % in Figure 36.

[00262] 23. DISTRIBUTED DESYNC ALGORITHM

[00263] As noted above prior art TDMA systems assign a specific time slot within a predefined time frame to each device. This assignment, however, consumes significant resources and accordingly the inventors have established a method that can maximize channel utilisation without the requirement of a centralize determination of time slot usage. The method employs the Listen Before Talk (Clear Channel Assessment or CCA) result in order to drift the network schedule in a manner that reduces the likelihoods of collisions. When a transmitter is ready to transmit, it performs a CCA. If the channel is currently used then this information us used to delay the next timeslot in order to desynchronize the link.

[00264] The delay may be fixed, variable or random. Whether the delay is established as fixed, variable or random may be established in dependence upon one or more factors including, but not limited to, historical data, recent channel data and current channel data. What type of delay is established and where the delay is fixed or variable the magnitude of the delay may be defined by one or more ML or Al processes. Within an exemplary algorithm implementing the method one or more other metrics including, but not limited to, PER, NACK, Rejected Frame Ratio, etc. may also be used in the exemplary novel algorithm.

[00265] Embodiments of the invention address limitations within the prior art by employing CCA to determine when a schedule adjustment is required. As noted above this Distributed Desync algorithm may be combined with a Listen Before Talk algorithm such as described in Section 6.

[00266] This inventive mechanism provides a replacement for an existing Random Datarate Offset (RDO) mechanism. The existing RDO mechanism adds drift to avoid devices performing CCA checks at the same time and not seeing each other. The amount of drift would increased by 1 phase locked loop (PLL) cycle (48.83 ns) every 10 ms. This mechanism relies heavily on the number of CCA retries possible and could result in situations where a link would not have sufficient CCA retries to avoid a collision. The inventors also established that the existing mechanism did not completely resolve network locking issues either.

[00267] Accordingly, to address this the inventors added a random offset at each transmission, TX Jitter. This mechanism adds a random offset to the transmission (between -1.5625 ps to 1.5625 ps although other ranges may be employed without departing from the scope of the invention) to enable devices or networks to each other when they are locked together. The inventors have further enhanced this concept to establish the distributed desynchronization (desync) (DDS) mechanism below which seeks to drift a network or radio(s) based on the number of CCA retries required for a successful transmission. The distributed desynchronization system (DDS) architecture relies to an increased degree on metrics of the network state rather than simply adding randomness to timing. Accordingly, the DDS allows networks / radios to de-synchronize themselves from other networks / radios.

[00268] In order to desynchronize networks (used herein for simplicity but may refer to networks, a radio or set of radios) the number of CCA retries and the time between each of CCA retries is used as a metric to define how much drift is required for each network. For example, Figure 37 depicts the scenario where Network 2 requires 1 CCA retry to transmit its payload and Network 3 requires 2 CCA retry to transmit its payload. After the DDS process the networks are de-phased as depicted in Figure 38.

[00269] Within the following paragraphs specific aspects of the DDS are described.

[00270] CCA Metric. Within the DDS the CCA metric is employed as an indicator for the distributed desync mechanism. If a link does not have CCA retry capabilities, the distributed desync cannot be implemented. When CCA retry is enabled it must be employed correctly. For instance, only the CCA retry count of a successful transmission should be used as an indicator for the network drift. Otherwise, there is no way to know if the CCA retry value is valid. Furthermore, the CCA settings must be set properly to allow for a valid reading. A CCA threshold of 25 (for an exemplary UWB radio designed and implemented by the inventors at Spark Microsystems, the SR1020) seems to be an optimal value.

[00271] Link Synchronization'. Adding offsets to a transmission can impact the synchronization between the coordinator and its nodes. To ensure synchronization is not lost, the offset of a transmission must be limited to make sure that its stays within the receiver’s receive window. Furthermore, an offset should not be applied if the last transmission was not successful. Otherwise, the synchronization could be lost during a packet loss burst (due for example to either collisions or high attenuation).

[00272] Non-Symmetric Link: A concurrency mechanism is particularly effective when all networks are symmetric as all transmissions will be de-phased to optimize air-time usage. When two networks are not symmetric, they can still de-phase themselves to reduce the amount of CCA retries required, but there is a higher chance of getting some collisions on some of the transmissions. Accordingly, the offset on the network may, for example, only be applied when a certain ratio of transmission is established using CCA retry. The number of CCA retry used could be accumulated over a fixed amount of time. This would represent the rolling average of CCA retry and a threshold could be set based on that.

[00273] Low Datarate Coordinator: As the DDS mechanism depends on CCA retry metrics obtained when transmitting packets, the ability to find other networks is linked to the framerate of the TX connections of the coordinator. One way to improve this, may for example, be to add feedback from the nodes to the coordinator of their average CCA retry count.

[00274] Hidden Node Problem: One of the biggest concurrency problems when using CCA is the hidden node problem. This is when two devices cannot detect each other but can cormpt each other’s transmissions by transmitting at the same time. A solution to this can be the same as for the “low datarate coordinator” problem as if nodes share their CCA metrics to the coordinator, the coordinator has a better overview of the whole network.

[00275] Simultaneous Transmissions: On network startup or with non-symmetric networks an issue may arise where both networks try to transmit at the same time. In that case, they would both do the CCA check at the same time and not see each other. To address this issue, the DDS introduces some randomness into the network transmission time. This makes it unlikely that networks will stay locked together for a long time. The induced randomness should not be at a level sufficient to block the ability of the DDS to drift the network nor cause link desynchronization either.

[00276] Specific details are given in the above description to provide a thorough understanding of the embodiments. However, it is understood that the embodiments may be practiced without these specific details. For example, circuits may be shown in block diagrams in order not to obscure the embodiments in unnecessary detail. In other instances, well-known circuits, processes, algorithms, structures, and techniques may be shown without unnecessary detail in order to avoid obscuring the embodiments.

[00277] Implementation of the techniques, blocks, steps and means described above may be done in various ways. For example, these techniques, blocks, steps and means may be implemented in hardware, software, or a combination thereof. For a hardware implementation, the processing units may be implemented within one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, controllers, micro-controllers, microprocessors, other electronic units designed to perform the functions described above and/or a combination thereof.

[00278] The foregoing disclosure of the exemplary embodiments of the present invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Many variations and modifications of the embodiments described herein will be apparent to one of ordinary skill in the art in light of the above disclosure. The scope of the invention is to be defined only by the claims appended hereto, and by their equivalents.

[00279] Further, in describing representative embodiments of the present invention, the specification may have presented the method and/or process of the present invention as a particular sequence of steps. However, to the extent that the method or process does not rely on the particular order of steps set forth herein, the method or process should not be limited to the particular sequence of steps described. As one of ordinary skill in the art would appreciate, other sequences of steps may be possible. Therefore, the particular order of the steps set forth in the specification should not be constmed as limitations on the claims. In addition, the claims directed to the method and/or process of the present invention should not be limited to the performance of their steps in the order written, and one skilled in the art can readily appreciate that the sequences may be varied and still remain within the spirit and scope of the present invention.

Claims

CLAIMS What is claimed is:

1. A method comprising the steps of: establishing a wireless radio to listen to a defined channel; establishing an energy detection threshold; listening with the wireless radio to the defined channel for predefined period of time; determining whether the received energy detected whilst listening to the defined channel for predefined period of time exceeds the energy detection threshold; upon a positive determination the received energy detected whilst listening to the defined channel for predefined period of time exceeds the energy detection threshold executing a process comprising the steps of: determining whether a maximum number of listening retries has been exceed or not; upon a positive determination that the maximum number of listening retries has been exceeded either aborting the method or transmitting a frame of data to be transmitted upon the defined channel; and upon a negative determination that the maximum number of listening retries has been exceeded waiting for a defined wait-time and then returning to the step of listening; and upon a negative determination the received energy detected whilst listening to the defined channel for predefined period of time exceeds the energy detection threshold transmitting the frame of data immediately upon the defined channel.

2. The method according to claim 1, wherein the defined channel is one of a current channel, a next frequency within a frequency hopping pattern, a next sub-band of a band hopping pattern and another channel the radio will move to.

3. The method according to claim 1, wherein at least one of: the channel is one of a set of channels which are sensed sequentially by the wireless radio; the channel is one of the set of channels which are sensed concurrently by the wireless radio; and the channel is one of a set of channels the wireless radio is currently transmitting a portion of a frame of data upon and the channel is one of a set of channels the wireless radio senses during the duration of the frame of data.

4. The method according to claim 1 , wherein the energy detection threshold is a dynamic value established in dependence upon analysis of channel data relating to the defined channel, the channel data comprising at least one of received number of signals indicator data and received signal strength indication data; and the analysis is performed by at least one of a machine learning process and an artificial intelligence process.

5. The method according to claim 1, wherein the defined wait time is one of fixed, variable and pseudo-random; which of the fixed, variable and pseudo-random is established by at least one of a machine learning process and an artificial intelligence process applied upon data associated with one or more factors selected from the group comprising historical channel data of the defined channel, recent channel data of the defined channel and current channel data of the defined channel; the magnitude of the fixed wait time, range of the variable wait time and range of the pseudorandom wait time is defined by at least one of a machine learning process and an artificial intelligence process applied to data associated with the one or more factors.

6. A method comprising the steps of: waiting by a controller of the wireless radio to receive a defined number of frames from a set of radios comprising at least an active radio and a non-active radio; computing with the controller a normalized received signal strength indication (RS SI) average of the defined number of frames for each radio within the set of radios; determining with the controller if the RSSI average of the non-active radio is greater than the RSSI average of the active radio by a defined margin; upon a negative determination that the RSSI average of the non-active radio is greater than the RSSI average of the active radio by the defined margin the method returns to the step of waiting; and upon a positive determination that the RSSI average of the non-active radio RSSI is greater than the active radio RSSI average of the active radio by the defined margin the controller reconfigures such that the non-active radio becomes the active radio and the previously active radio becomes the non-active radio before returning to the step of waiting.

7. A method comprising the steps of: waiting by a controller of the wireless radio to receive M frames from a set of N radios comprising an active radio and N-l non-active radios; computing with the controller a normalized received signal strength indication (RSSI) average of the M for each radio within the set of N radios; determining with the controller if an RSSI average of any non-active radio of the N-l non- active radios is greater than the RSSI average of the active radio by a defined margin; upon a negative determination that any RSSI average of any non-active radio RSSI of the N-l non-active radios is greater than the RSSI average of the active radio by the defined margin the method returns to the step of waiting; upon a positive determination that an RSSI average of a defined non-active radio RSSI is greater than the active radio RSSI average of the active radio by the defined margin the controller reconfigures such that the defined non-active radio becomes the active radio and the previously active radio becomes a non-active radio before returning to the step of waiting; and

M and N are positive integers, N > 2 and M > 1.

8. The method according to claim 8, wherein if the determination with the controller determines that there is more than one non-active radio RSSI average of the N-l non-active radios greater than the RSSI average of the active radio by the defined margin then the controller determines which non-active radio of the non-active radios with RSSI averages greater than the RSSI average of the active radio to employ either: based upon historical data of the non-active radios having RSSI averages greater than the RSSI average of the active radio; pseudo-randomly; or upon a round robin selection.

9. The method according to claim 8, wherein the defined margin is dynamically established; and the defined margin is established by at least one of a machine learning process and an artificial intelligence process applied upon data associated with one or more factors selected from the group comprising recent RSSI measurements, historical RSSI measurements, a number of dropped frames within a link between the wireless radio and the active radio, a data rate of the link and a cyclic redundancy check of the link.

10. A method comprising the steps of: configurating a wireless radio to receive data upon a frequency band of a set of frequency bands; waiting a defined delay; performing a listen-before-talk process to determine whether the frequency band of a set of frequency bands is clear; determining whether the listen-before -talk process was aborted; and upon determining that the listen-before-talk process was aborted configuring the wireless radio to another frequency band of a set of frequency bands and looping back to the step of waiting.

11. The method according to claim 10, wherein the listen-before-talk process comprises the steps of: establishing an energy detection threshold; listening with the wireless radio to the frequency band of the set of frequency bands for predefined period of time; determining whether the received energy detected whilst listening to the frequency band of the set of frequency bands for predefined period of time exceeds the energy detection threshold; upon a positive determination the received energy detected whilst listening to the frequency band of the set of frequency bands for predefined period of time exceeds the energy detection threshold executing a process comprising the steps of: determining whether a maximum number of listening retries has been exceed or not; upon a positive determination that the maximum number of listening retries has been exceeded aborting the method; upon a negative determination that the maximum number of listening retries has been exceeded waiting for a defined wait-time and then returning to the step of listening; upon a negative determination the received energy detected whilst listening to the frequency band of the set of frequency bands for predefined period of time exceeds the energy detection threshold transmitting the frame of data immediately upon the frequency band of the set of frequency bands.

12. The method according to claim 10, wherein the frequency band of the set of frequency bands is established according to one of: a pseudo-random determination; a pseudo-random point within a sequence; a pseudo-random point within a pseudo-random sequence.

13. The method according to claim 10, wherein the frequency band of the set of frequency bands and the another frequency band of the set of frequency bands are each established according to one of: a pseudo-random determination; a pseudo-random point within a sequence; a pseudo-random point within a pseudo-random sequence.

14. A method comprising the steps of: splitting with a processor an uncompressed audio stream to configure the payload of a wireless link between a wireless radio comprising the processor and another wireless radio; determining whether the wireless radio has enabled fallback; upon a positive determination that fallback has been enabled executing the steps of: compressing the split uncompressed audio to generate compressed audio; and transmitting the compressed audio; and upon a negative determination that fallback has been enabled transmitting the split uncompressed audio.

15. A method comprising the steps of: establishing a link between a wireless radio and another wireless radio according to a current transmission mode; determining a size of a transmission queue at the wireless radio for the link; determining whether the size of the transmission quote exceeds a threshold value; upon a negative determination that the size of the transmission quote exceeds the threshold value transmitting a frame according to the current transmission mode and returning to the step of determining the size of the transmission queue; and upon a positive determination that the size of the transmission quote exceeds the threshold value establishing a fallback trigger to thereby establish a fallback mode of the wireless radio wherein data to be transmitted within subsequent frames is compressed.

16. The method according to claim 15, wherein the threshold value is established in dependence upon either increasing a speed of the process or meeting a latency requirement of the link and reducing a likelihood of falsely setting the fallback trigger.

17. A method comprising the steps of: establishing a link between a wireless radio and another wireless radio according to a current transmission mode; determining current values of a link margin for the link and a clear channel assessment for the link; determining whether the current value of the link margin for the link exceeds a threshold value and the current value for the clear channel assessment is below another threshold value; upon a negative determination that the current value of the link margin for the link exceeds the threshold value and the current value for the clear channel assessment is below the another threshold value transmitting a frame according to the current transmission mode and returning to the step of determining the current values of the link margin for the link and the clear channel assessment for the link; and upon a positive determination that the current value of the link margin for the link exceeds the threshold value and the current value for the clear channel assessment is below the another threshold value clearing a fallback trigger to thereby establish transmission of data within subsequent frames uncompressed.

18. A method comprising the steps of: establishing a link between a wireless radio and another wireless radio according to a current transmission mode; transmitting a dummy frame one a retransmission timeslot of a set of retransmission timeslots defined for a channel N of M channels of the link; determining whether the dummy frame transmission was successful; upon a positive determination that the dummy frame transmission was successful proceeding to the step of determining whether all M channels have been established as clear; upon a negative determination that the dummy frame transmission was successful executing a wait of defined duration and returning to the step of transmitting the dummy frame; determining whether all M channels of the link have been established as clear; upon a positive determination that all M channels of the link have been established as clear clearing a fallback flag or fallback trigger associated with the link; and upon a negative determination that all M channels of the link have been established as clear executing a wait of another defined duration, changing the channel N to a channel not yet verified as clear of the M channels of the link and returning to the step of transmitting the dummy frame; wherein when the fallback flag or fallback trigger associated with the link is set the data to be transmitted is compressed prior to transmission and when the fallback flag or fallback trigger associated with the link is not set the data to be transmitted is not compressed prior to transmission.

19. An antenna comprising: a circuit board; a first microstrip line disposed on one side of a virtual axis of the circuit board on a first surface of the circuit board comprising an embedded open stub at a location along the first microstrip line between a first end of the first microstrip line and a second distal end of the first microstrip and a bent open stub at the location along the first microstrip line; a second microstrip line disposed on another side of the virtual axis of the circuit board on the first surface of the circuit board comprising another embedded open stub at a location along the second microstrip line between a first end of the second microstrip line and a second distal end of the second microstrip and a bent open stub at the location along the second microstrip line; a first ground plane slot disposed within a ground plane on the one side of the virtual axis of the circuit board on a second surface of the circuit board distal to the first surface at a predetermined location relative to location along the first microstrip line; and a second ground plane slot disposed within the ground plane on the another side of the virtual axis of the circuit board on the second surface of the circuit board distal to the first surface at another predetermined location relative the location along the second microstrip line.