Methods and devices for positioning and beamforming in coverage enhancing device-assisted systems

Abstract

A method is disclosed, the method may be performed by a first wireless node (e.g., a CED controlling node, a wireless device, an access point, or a radio access network node), for improving communication via a CED (e.g., a reconfigurable intelligent surface, RIS) by using delay compensation. The method comprises obtaining a delay configuration indicative of a first delay caused by the CED and associated with a beam configuration of the CED. The delay configuration enables the first wireless node and / or a second wireless node to compensate for propagation delays associated with the CED.

Description

[0001] METHODS AND DEVICES FOR POSITIONING AND BEAMFORMING IN COVERAGE ENHANCING DEVICE-ASSISTED SYSTEMS

[0002] The present disclosure relates to methods for improving communication via a coverage enhancing device, CED, by using delay compensation, and to related devices.

[0003] BACKGROUND

[0004] Communication between devices in wireless communication systems may be challenging when a direct line-of-sight between two devices is obstructed. For example, ranging or positioning operations in wireless communication systems typically rely on a calculation for the time of flight of signals between sending and receiving devices. Such operations can be complicated when a direct line-of-sight between two devices is obstructed.

[0005] Attempts have been made to mitigate issues that arise from such line-of-sight obstructions. Yet some approaches, including employing certain intermediary devices to reflect or retransmit signals between devices, lead to unreliable results for certain ratios of signal-pulse duration and differences in propagation delay. For example, when differences in propagation delay are within the same order of magnitude as a symbol duration, certain assumptions or simplified approaches to positioning and / or ranging made in some systems yield unreliable results.

[0006] SUMMARY

[0007] Certain methods of operating systems can overcome such problems. By way of example, a CED, such as reconfigurable intelligent surfaces, RIS, may be operated by recognizing certain propagation characteristics within a system. For systems with very wide bandwidths, e.g., UWB systems, and for CEDs with large aperture, operating behavior may be different than similar devices operated in narrowband systems. Operational characteristics may also depend on other system parameters; for example, as described herein, operational assumptions or expectations may change when a propagation delay is within the same order of magnitude as the duration of symbols used in the system.

[0008] Accordingly, there is a need for devices and methods for improving communication via a CED by using delay compensation, which mitigate, alleviate or address the shortcomings existing and provide that devices can communicate with one another via a CED while compensating for propagation delays associated with or introduced by such communication. The improvement in communication may in turn provide accurate positioning without line-of-sight communication paths.

[0009] A method is disclosed, the method may be performed by a first wireless node (e.g., a CED controlling node, a wireless device, an access point, or a radio access network node), for improving communication via a CED (e.g., a RIS) by using delay compensation. The method comprises obtaining a delay configuration indicative of a first delay caused by the CED and associated with a beam configuration of the CED. The delay configuration may enable the first wireless node and / or a second wireless node to compensate for propagation delays associated with the CED.

[0010] Further, a device, referred to as a wireless node (such as the first wireless node as disclosed herein), is disclosed. The wireless node comprises memory circuitry, processor circuitry, and a wireless interface. The wireless node may be configured to perform any of the methods disclosed herein, such as any methods performed by the first wireless node.

[0011] It is an advantage of the present disclosure that the disclosed method and wireless node enable time-of-flight calculations supporting ranging / positioning operations among devices to be reliable despite lack of light-of-sight between devices and despite propagation delays introduced by intermediary devices, such as by a CED. In other words, it is an advantage of the present disclosure that devices may communicate with one another via a CED while compensating for propagation delays associated with or introduced by such communication.

[0012] It is a further advantage of the present disclosure that devices may be configured to communicate with a CED without a priori information of a delay configuration of the CED.

[0013] Further, a method performed by CED (e.g., a RIS) for communication via the CED using delay compensation is disclosed. The method comprises obtaining a first delay configuration based on a beam configuration associated with one or more delay configurations to be applied by the CED.

[0014] Further, a device, referred to as a CED, is disclosed. The CED comprises memory circuitry, processor circuitry, and a wireless interface. The CED may be configured to perform any of the methods disclosed herein, such as any methods performed by the CED. It is an advantage of the present disclosure that the disclosed method and CED enable time-of-flight calculations supporting ranging / positioning operations among devices to be reliable despite lack of light-of-sight between devices and despite propagation delays introduced by intermediary devices, such as by a CED. In other words, it is an advantage of the present disclosure that the disclosed method and CED enable devices to communicate with one another via a CED while compensating for propagation delays associated with or introduced by such communication.

[0015] It is a further advantage of the present disclosure beamforming gains, including double beamforming and / or full beam forming, may be realized in systems that employ a CED.

[0016] It is a further advantage of the present disclosure that certain use cases, such as effective management of crowded entries to public transit systems, may be enabled by deploying systems according to the present disclosure.

[0017] BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The above and other features and advantages of the present disclosure will become readily apparent to those skilled in the art by the following detailed description of example embodiments thereof with reference to the attached drawings, in which:

[0019] Fig. 1 A is a diagram illustrating an example wireless communication system comprising examples of wireless nodes, including network nodes, and an example CED according to this disclosure,

[0020] Fig. 1B illustrates an example scenario where an example technique as disclosed herein is applied,

[0021] Fig. 2 is a flowchart illustrating one or more example methods, performed by a wireless node, for improving communication via a CED according to this disclosure,

[0022] Fig. 3 is a flowchart illustrating one or more example methods, performed by a CED, for communication via the CED using delay compensation according to this disclosure, Fig. 4 is a block diagram illustrating an example wireless node according to this disclosure,

[0023] Fig. 5 is a block diagram illustrating an example CED according to this disclosure, Figs. 6A-6C are diagrams illustrating examples of one or more CEDs, or one or more aspects of CEDs, according to this disclosure, Figs. 7A-7B are signalling diagrams illustrating example signalling between example wireless nodes and / or an example CED, according to this disclosure,

[0024] Fig. 8 is a signalling diagram illustrating example signalling between example wireless nodes and / or an example CED, according to this disclosure,

[0025] Fig. 9 illustrates an example scenario where an example technique as disclosed herein is applied,

[0026] Figs. 10A-10C are plots illustrating examples of one or more advantages of wireless nodes and / or CEDs operating according to this disclosure.

[0027] DETAILED DESCRIPTION

[0028] Various example embodiments and details are described hereinafter, with reference to the figures when relevant. It should be noted that the figures may or may not be drawn to scale and that elements of similar structures or functions are represented by like reference numerals throughout the figures. It should also be noted that the figures are only intended to facilitate the description of the embodiments. They are not intended as an exhaustive description of the disclosure or as a limitation on the scope of the disclosure. In addition, an illustrated embodiment need not have all the aspects or advantages shown. An aspect or an advantage described in conjunction with a particular embodiment is not necessarily limited to that embodiment and can be practiced in any other embodiments even if not so illustrated, or if not so explicitly described.

[0029] The figures are schematic and simplified for clarity, and they merely show details which aid understanding the disclosure, while other details have been left out. Throughout, the same reference numerals are used for identical or corresponding parts.

[0030] In wireless communications, the narrowband assumption may be seen as an important premise. It is widely adopted in many technical analyses of modern systems. In particular, studies involving CEDs, such as reconfigurable intelligent surfaces RIS, often rely on this assumption. However, in systems with very wide bandwidths, such as Ultra-Wideband, UWB, systems, and for CEDs, such as RISs, with large apertures, the narrowband assumption may not hold. This presents new challenges that the present disclosure mitigates, alleviates, or addresses. For example, the integration of UWB and CEDs, such as RISs, presents significant challenges. This is primarily because UWB’s extensive bandwidth invalidates the narrowband assumption, even with a moderately sized CED, such as RIS. In other words, the propagation delays for signals reflected by different CED elements vary and cannot be assumed small in comparison with the signa-pulse duration, such as with the reciprocal of the bandwidth. For example, the CED may have to apply phase shifts to the reflected signals.

[0031] As a result, the beamforming gain of the CED, such as RIS, is diminished when applied to UWB signals. The extent of this loss depends on the relationship between the UWB bandwidth and the CED aperture. In the present disclosure, this issue is addressed, achieving improved beamforming gain, such as full beamforming gain and more, despite these limitations.

[0032] Fig. 1A is a diagram illustrating an example wireless communication system 1 according to this disclosure. The wireless communication system 1 comprises wireless nodes (e.g., wireless devices) 300 and 300A, a network node 400 and a core network (CN) node 600.

[0033] As discussed in detail herein, the present disclosure relates to a wireless communication system 1 comprising a cellular system, for example, a 3GPP wireless communication system. Additionally or alternatively, system 1, or portions of it, may be configured for ultrawideband, UWB, communication according to an IEEE 802.15.4 specification.

[0034] A network node disclosed herein refers to a radio access network (RAN) node operating in the radio access network, such as a base station, an evolved Node B, eNBs, a global Node B, gNBs in NR, and / or a transmission and reception point (TRP). In one or more examples, the RAN node is a functional unit which may be distributed in several physical units.

[0035] A CN node disclosed herein refers to a network node operating in the core network, such as in the Evolved Packet Core Network, EPC, and / or a 5G Core Network, 5GC. Examples of CN nodes in EPC include a Mobility Management Entity, MME.

[0036] In one or more examples, the CN node is a functional unit which may be distributed in several physical units. The wireless communication system 1 described herein may comprise one or more wireless devices 300, and / or one or more network nodes 400, such as one or more of: a base station, an eNB, a global Node B, gNB, and / or an access point.

[0037] The wireless communication system 1 may comprise a coverage enhancing device (CED) 800, such as a CED as disclosed herein. The CED 800 may be one or more of a smart repeater, a reflective intelligent surface (RIS), a network controlled repeater (NCR), and / or another wireless device (WD). The CED 800 may provide coverage enhancement for devices using 5G and beyond. In one or more examples, the CED 800 provides coverage enhancement for devices communicating with UWB signals. The CED 800 may be configurable by a wireless node 300, the network node 400 and / or the CN node 600, and may be used to improve signal coverage in the wireless communication system 1. CN node 600 may communicate with network node 400 via link 12, which may be a wired or wireless link.

[0038] The CED 800 may be used to retransmit, such as forward, signals, such as data and / or control signals, between the network node 400 and the wireless node 300. The retransmission can be advantageous when the wireless node 300 is located at hard-to-reach locations, such as at a border of a coverage area of the network node 400 and / or when a direct link between wireless node 300A and wireless node 300 or between the network node 400 and the wireless node 300 is obstructed. It may be appreciated that the CED 800 can also be used to increase the multiple components and / or channel rank to support MIMO communication between the network node 400 and the wireless node 300, even in a well-covered area.

[0039] The present disclosure may take advantage of a CED with an adjustable delay configuration. The delay configuration may enable the wireless node 300 and / or wireless node 300A to compensate for propagation delays associated with communications via CED 800. Such compensation may allow wireless node 300 and / or wireless node 300A to perform a reliable positioning or ranging operation when LOS between wireless nodes is not available.

[0040] The CED 800 may comprise a plurality of antenna elements that can be configured with a respective phase shift. By controlling the phase shifts, such as jointly controlling the phase shifts, an incoming and / or outgoing angle of a signal received and / or transmitted by the CED 800 can be controlled and / or adapted. Additionally or alternatively, the CED 800 may comprise a plurality of delay elements that can be configured to change the actual or apparent propagation delay of signals transmitted from and / or received by a wireless node 300, 300A and / or a network node 400. For example, when the CED applies a phase shift, it may be seen as the CED applying a delay being less than, such as shorter than, a wavelength c / f, where c is the speed of light and f is the frequency, such as carrier frequency. On the other hand, a delay as disclosed herein, such as the first delay, may be seen as the CED applying a delay of more than, such as longer than, a wavelength c / f, where c is the speed of light and f is the frequency, such as carrier frequency. It may be appreciated that the wavelength is a distance in meter, m, and therefore the delay applied is in seconds, s. Therefore, in the present disclosure, when a delay is applied, such as the first delay, it may be understood that a longer delay than a delay resulting from a phase shift is applied, such as a delay longer than a wavelength. The configurable delay of the CED 800 is described in further detail herein.

[0041] In one or more examples or embodiments, the CED 800 receives signals at a plurality of antenna elements, such as a plurality of first antenna elements. The signals are then phase shifted and / or delayed as explained earlier and then retransmitted from the CED 800. The signals may be retransmitted by the same plurality of first antenna elements and alternatively or additionally, the signals may be retransmitted by a different plurality of antenna elements, such as a plurality of second antenna elements. It may be appreciated that each antenna element of the antenna elements may be configured with an individual delay associated with a respective antenna element. For example, each antenna element of the plurality of antenna elements may apply different delays. This may be for configuring the focus of the signal to be retransmitted and / or forwarded, such as configuring the focus of a wideband signal.

[0042] For example, a CED of the type NCR may be enabled for full duplex. An NCR may have two separate antenna arrays, one array toward an access side (such as toward an object) and another array toward a backhaul side (such as toward a NN). In one or more example methods, the angle of incoming and outgoing signals can be controlled by controlling the relative phase between antenna elements of the CED 800. The phase shift may be a capacitor-based phase shift and / or a true time delay line, such as a time domain shift, between antenna elements of the CED 800. The wireless node 300 may be configured to communicate with wireless node 300A and / or the network node 400 directly via the wireless link (or radio access link) 10 and / or via the CED 800 via wireless link 10A. The wireless link 10A may herein be referred to as a reflected, such as retransmitted, wireless link. The CED 800 may be controlled by one or more network nodes, such as the network node 400, or one or more wireless devices, such as the wireless nodes 300 and / or 300A.

[0043] In one or more example embodiments or examples, the network node 400 may be seen as the CED controlling node, such as CED controlling node 700. The one or more network nodes or wireless devices controlling the CED 800 may herein be referred to as coverage enhancing device controlling nodes. In one or more examples, the coverage enhancing device controlling node can be a CN node, such as the CN node 600 in Fig 1A. In one or more examples, the coverage enhancing device controlling node can be a node in an external network that can access the CED 800, for example through the internet via a gateway function.

[0044] CED 800 may have a reference point, such as reference point 50 (e.g., a point on CED 800) or reference point 50A (e.g., a point external to CED 800). The reference point 50 and / or 50A may be at least one of an antenna elements of the CED, a portion of the CED between antenna elements, a portion of the CED exclusive of antenna elements, ora location external to the CED, or any combination thereof. In one or more examples, reference 50A is at an access point or wireless device. The reference point 50 and / or 50A may be defined by an operator of system 1, the CED controlling node 400, or by other nodes within system 1. The location of reference point 50 and / or 50A may depend on the relative locations of wireless nodes 300 and 300A, and such locations of the reference point may be used in delay compensation to enable ranging or position calculations as described herein.

[0045] According to the current disclosure, the operation of system 1 and respective nodes of the system may affect the accuracy ranging or positioning operations by wireless nodes 300 and / or 300A. For example, engineering or technical principles to anticipate, calculate, or estimate certain aspects of time delays associated with bearing signals in narrowband systems, which may be referred to as a “narrowband assumption” may yield inaccurate or undesirable results for a positioning operation when a system employs wideband signals or when other characteristics of a system is present. Whether a system is narrowband system or whether applying a narrowband assumption is desirable is relative. The skilled person will recognize that the solutions described herein, and the particular problems solved, will apply for a variety of bandwidths and signals. Technical problems identified herein, and the solutions proposed (and the advantages of such solutions), are not limited to any specific bandwidth.

[0046] For example, a signal s(t) may be transmitted via wireless link 10 from wireless node 300, towards an N-element CED, such as CED 800, and the reflected signal received via wireless link 10A at a receiver point, such as wireless node 300A. The transmitted signal may be expressed as

[0047] s(t) = exp(j2πfct)β(t) (1)

[0048] where fcis the RF carrier and β(t) is the information bearing signal whose bandwidth, W, satisfies W ≪ fc. Each of the N elements of CED 800 receives the signal, applies a phase shift, and then re-radiates the signal. This may produce a signal at the receiver, in the absence of noise, which reads

[0049]

[0050] where α is a common path loss for all elements, τnis the total propagation delay the signal undergoes through CED 800 element n, and θnis a phase shift at element n.

[0051] In the example, inserting Equation 1 into Equation 2 produces

[0052]

[0053] For the narrowband assumption, it may be assumed that τn≪ 1 / W. The quantity 1 / W measures the rate of change of the signal

[0054]

[0055] and the narrowband assumption implies that the signal / ?(t) remains largely unchanged during Tnseconds. Thus, β(t − τn) ≈ β(t which yields r(t) ≈ α exp

[0056]

[0057] For an example CED 800, it may be understood that θn= 2πfcτnwhich results in

[0058] r(t) ≈ αN exp(j2πfct)β(t) = αNs(t). (4)

[0059] The received signal r(t) is an undistorted version of the transmit signal s(t), but where an amplitude scaling of N is achieved.

[0060] But this narrowband assumption may not hold for systems that employ wide bandwidth and / or for CEDs with a large aperture. Nor does it hold, for example, in systems that have a certain ratio of signal-pulse duration to difference propagation delay, such as that observable in ultrawideband, UWB, systems or certain frequency ranges or configurations of cellular systems, including, for example, Frequency Range 1, FR1, and Frequency Range 2, FR2, specified in 3GPP Release 18.

[0061] As described in more detail herein, to address these and other problems, a first wireless node, such as wireless node 300, wireless node 300A, or CED controlling node 600, may be configured for and operate to improve communication via CED 800 by using delay compensation. This may include obtaining a delay configuration indicative of a first delay caused by CED 800 and associated with a beam configuration of CED 800. The delay configuration may enable the wireless node 300, wireless node 300A, and or network node 400 to compensate for propagation delays associated with CED 800. The delay configuration may be associated with a reference point relative to CED 800, such as reference point 50 or reference point 50A.

[0062] Likewise, CED 800 may communicate using delay compensation. CED 800 may obtain a first delay configuration based on a beam configuration associated with one or more delay configurations to be applied by CED 800.

[0063] Fig. 1B illustrates an example scenario where an example technique as disclosed herein is applied, Fig. 1B is a diagram illustrating an example wireless communication system comprising examples of wireless nodes and an example CED according to this disclosure. System 2 of Fig. 1B includes wireless node 300 (such as a UE), wireless node 300A, and CED 800 having an associated reference point 50 and / or 50A. Wireless nodes 300 and 300A may communicate with one another via CED 800 on wireless links 10, 10A, 11, and / or 11 A. Wireless links 11 and 11 A represent different signal paths between the same transmitter and receiver pair as wireless links 10 and 10A; wireless links 10, 10A, 11 and 11A may thus be understood as examples or instances of similar wireless communication signals. Wireless node 300, wireless node 300A, and CED 800 may be examples of the wireless nodes and CED described with reference to FIG. 1A.

[0064] Although described with reference to wireless nodes 300 and 300A, a network node, such as network node 400 and / or 700, as shown in Fig. 1A may likewise communicate via the CED 800 using similar techniques. For example, wireless node 300A may represent or understood as a network node 400.

[0065] Further benefits of the present disclosure are described in the context of problems understood by reference to Fig. 1B. By way of example, wireless links 10 and 10A and wireless links 11 and 11A may have a bandwidth around W = 500MHz and a signal-pulse shape with 2ns duration. System 2 may represent a room with various obstructions, including crowds of people, or other closed environment that has a ceiling 3 meters above a floor, and in which CED 800 is 2 meters long and centered in a room having a length of about 6 meters. Wireless node 300A may have an effective height above the floor of about 1.5 meters. In one or more examples, the signal comprising wireless link 10, which may be understood to have a value β(t) formed as a data-weighted signal-pulse train of such signal-pulses. In one or more examples, wireless node 300 is attempting to connect to a hub at wireless node 300A by means of wireless links 10, 10A, 11, and 11A (e.g., UWB links) in a crowded environment in which a direct path between wireless nodes 300 and 300A, or line-of-sight, LOS, is obstructed or blocked.

[0066] In such examples, the propagation path via wireless links 11 and 11 A is about 0.77m longer than propagation path of wireless links 10 and 10A. Converting the difference in lengths of propagation paths to a difference of propagation delay results in an approximately 2.6ns time difference between these two paths. With a 2ns signal-pulse duration, it may be seen that the narrowband assumption β(t − 2.6 × 10-9) ≈ β(t) is not applicable. In other words, the narrowband assumption applied to some scenarios described herein may yield unreliable results. In the example of system 2 depicted in Fig. 1 B, the difference in propagation delay across CED 800, i.e., the difference in propagation delay between wireless links 10 and 10A and wireless links 11 and 11 A, is not a consequence of the distance between the CED 800 and wireless devices 300. Rather, the difference in propagation delay occurs irrespective of the relative locations of wireless nodes 300 (i.e., independent of the location of the receiver and transmitter). The delay as seen or experienced at wireless node 300 may be understood as the perceived delay (joint or accumulated) originating from all elements of the CED 800. As described herein, reliability of the narrowband assumption with respect to CED 800 may thus depend on bandwidth W and the aperture of CED 800.

[0067] Technical challenges may arise when systems operate in a manner that does not support the narrowband assumption. Several such examples and issues are described herein.

[0068] For instance, application of the narrowband assumption (or implementation of a system employing the narrowband assumption) may result in loss of beamforming gain. In Equation 3, above, the amplitude gain of an N-element CED 800 is N. In terms of signal power, this corresponds to an N2-fold gain. For example, with N = 100, one may expect a 40db gain. But if this does not occur, a significant or meaningful reduction of beamforming gain may result. Further, such a system may not realize beamforming gain because signal-pulses overlap.

[0069] Another potential problem that may arise from application of the narrowband assumption in the wideband context is loss of positioning and synchronization accuracy. Prior to communication, a synchronization step may be executed. In UWB contexts, this may include or be referred to as positioning. In such cases, the receiver may perform a correlation of the received signal with the waveform used by the transmitter. But the received waveform may be distorted due to the difference in propagation delays. This may result in a loss of both positioning and synchronization performance. As the aperture and / or bandwidth grow large, signals from CED 800 may superimpose destructively, rendering the signal at the receiver unreliable or unusable.

[0070] A third potential problem that may arise from the application of the narrowband assumption in the wideband context is an increase in complexity at the receiver and relatively worse throughput. Large propagation delay differences may cause signal-pulses to overlap in the time-domain. Unmitigated, such inter-symbol interference, ISI, at the receiver may have significant consequences; for strong ISI, including ISI induced by large CED aperture or bandwidth, the uncorrected or unmitigated bit error rate may be 50%. But certain countermeasures to address such issues may involve significant computational complexity, which may be impractical or unachievable in certain scenarios. Furthermore, such countermeasures may cause performance degradation that may be substantial and itself undesirable. The stronger the ISI, the more narrowband its transfer function may become. This reduces the overall bandwidth of the transmission. For data throughput, this may be more detrimental than the loss of beamforming gain as throughput reacts linearly to bandwidth but only logarithmically to power. ISI is thus unfavorable or undesirable in most cases, and thus it is often something to be avoided.

[0071] A fourth potential problem that may arise from the application of the narrowband assumption in the wideband context is the possibility of more complicated protocols to achieve reliable ranging. Many systems operating according to a UWB standard (e.g., IEEE802.15.4) operate on a basis or assumption that the first signal that arrives at the receiver is the one of interest. This would correspond to the LOS signal and may, for example, be used for time-of-flight computations. With CED-induced propagation delay differences, many or all CED-induced signal components are of interest and may include sufficient signal-to-noise ratio, SNR. But there may exist further multipath components with delays of their own that also interfere with the desired signal. To separate these undesired components from the CED-induced, desired components may involve significant computational complexity and may be challenging to integrate into standardized frameworks.

[0072] These and other technical issues may be apparent in a variety of use cases or practical applications. For example, in many cities, public transport networks form a critical part of the infrastructure that allows the inhabitants to travel to their wanted destinations. Public transport networks are strained during peak transit times. Thousands of passengers densely arranged (e.g., two or more passengers per square meter) may need to pass through a limited number of gates, in very short time periods (e.g., on the order of one second), with minimal disruptions. For efficiency, the gates need to collect fares, admit a traveler, and close to secure the entry within the allotted time period, which may be only a second. A framework for touchless gate operation may better manage heavy traffic than systems that rely on manual tap-to-admit systems or system that require insertion of a physical ticket. In such a system, a user may simply walk through a gate, obtaining access and conducting necessary transactions without additional manual processes. The system may use UWB to connect with a user’s payment device, such as a mobile phone or other UWB-enabled wireless device. This does, however, present a challenge when designing a UWB-based transport fare collection system is to achieve sufficient performance to allow the UWB devices in the gates to position and communicate with the devices of several passengers that are blocking the LOS path for each other as they approach the gates. Employing CED 800 as described herein can address the issue from an obstructed LOS.

[0073] Similar issues are seen in cellular networks as well. For example, in a 3GPP NR system, the single carrier bandwidth can be up to 100 MHz in, FR1, and 2000 MHz in, FR2.

[0074] Systems supporting carrier aggregation may also large effective bandwidth — up to 400 MHz in FR1 in Release 18, and even larger carrier aggregation bandwidths are likely to be supported in future systems. Such large relative bandwidths create expectations of similar challenges as described above.

[0075] The present disclosure thus describes methods and devices for wireless communication that provide solutions for, among other things, positioning / ranging problems arising from different propagation delays. These solutions may address issues associated with UWB positioning, such as in the public transit gate scenario, and various cellular networks, as described above.

[0076] Fig. 2 is a flowchart illustrating one or more example methods 100, e.g., performed by a wireless node, for improving communication via a CED according to this disclosure. For example, the method 100 may be a method of wireless communication according to this disclosure. In other words, the method 100 may be a method for improving communication via a CED by using delay compensation, such as a method for improving beamforming gain in a CED. The method 100 may be for a positioning or ranging operation for one or more wireless nodes, such as described with reference to Figs. 7B and 8. The method 100 may also provide for additional beamforming, as described with reference to Figs. 9, 10A, 10B, and 10C. The CED and wireless nodes are the CED 800 and wireless nodes 300 and 300A disclosed herein, such as in Figs. 1A, 1 B, 4, and 5. The method 100, which may be performed by a first wireless node (e.g., wireless node 300), comprises obtaining S108 a delay configuration indicative of a first delay caused by a CED (e.g., CED 800) and associated with a beam configuration of the CED. The delay configuration may be, for example, an indication of a processing delay for a reference point (e.g., reference point 50 and / or 50A). The delay configuration may comprise the first delay. In one or more examples, the first delay comprises a time value (such as a delay value) that may be used to compensate for propagation delays associated with the CED, such as used to determine a time of flight of a received signal. The first delay may be a value delta, as described herein, including with reference to Equation 9, below. It may be appreciated that the CED may compensate for propagation delays by introducing further delays to signals retransmitted, reflected, and / or forwarded by the CED. For example, each signal may be retransmitted, reflected, and / or forwarded by the CED with its own specific delay, e.g., to compensate for that signal’s specific propagation delay. In one or more example embodiments, each antenna element of the CED may retransmit, reflect, and / or forward a signal with its own specific delay, e.g., to compensate for that signal’s specific propagation delay. These further delays may result in a common global delay, e.g., the first delay, for all the signals received at the first wireless node and / or the second wireless node. In other words, the first delay may be seen as a global delay from the perspective of the first wireless node and / or the second wireless node. The first delay caused by the CED may be understood as a result of undefined propagation time due to various elements of the CED (e.g., as described with reference to Equation 8, below). The first delay being associated with the beam configuration of the CED may be understood as the delay configuration (e.g., the first delay) being beam specific. As described below with reference to Figs. 7B and 8, when the CED beam (e.g., the beam of a signal reflected from a CED) changes, the associated delay configuration may change. The delay configuration thus enables the first wireless node and / or a second wireless node (e.g., wireless node 300A) to compensate for propagation delays associated with the CED, as may be seen from the discussion of Fig. 7B below.

[0077] The first wireless node and / or the second wireless node may be a CED controlling node, a wireless device, an access point, or a radio access network node in various examples. The CED may be a reconfigurable intelligent surface, RIS. In one or more example embodiments, the delay configuration is associated with a reference point (e.g., reference point 50 and / or 50A) relative to the CED. In one or more example embodiments, the reference point is a point on the CED. In one or more example embodiments, the reference point is a point external to the CED. The reference point may be an antenna element of the CED, or it may be a different element that is between antenna elements, or it may be a different physical or intangible feature on the CED array. In one or more examples, the reference point is based on a location of a second wireless node. The reference point may, for example, be the second wireless node.

[0078] In one or more examples of the method, obtaining the delay configuration comprises receiving S108A, from the CED, signalling indicative of the delay configuration. In one or more examples, obtaining the delay configuration comprises retrieving S108B the delay configuration from memory of the first wireless device. In one or more examples, obtaining the delay configuration comprises obtaining S108C information associated with a lookup table that comprises the delay configuration. The information associated with the lookup table may comprise the lookup table. Or the information associated with the lookup table may comprise an index to, or configuration associated with, a value in the lookup table.

[0079] In one or more examples, the method comprises obtaining S104 first information associated with a first direction of a first signal transmitted to the CED from the first wireless node and / or from the second wireless node. The first information may be an angle or other characteristic of a signal transmitted from, for example, a wireless node 300, to the CED. In some examples, the first information may be understood as the initial signal 720A or the response signal 722A described with reference to Fig. 7. Additionally or alternatively, the method comprises receiving S102, from the CED, capability information that indicates the CED is configurable with the delay compensation configuration.

[0080] Capability information may be RRC signalling or other signalling that configures user and / or control planes of a wireless node. In one or more examples, capability information is information shared between nodes on, for example, a network layer, transport layer, or higher layer of a system protocol. In one or more examples, the method comprises transmitting S106 to the CED the beam configuration for the CED.

[0081] In one or more examples, the method comprises performing S110 a ranging operation based on the delay configuration. Fig. 3 is a flowchart illustrating one or more example methods 200 of wireless communication according to this disclosure. In other words, the method 200 may be a method for improving communication via a CED by using delay compensation. The method 200 may be for tuning a CED for delay compensation, such as described with reference to Figs. 6A, 6B, and 6C. The method 200 may be for a positioning or ranging operation for one or more wireless nodes, such as described with reference to Figs. 7B, and 8. The method 200 may also provide for additional beamforming, as described with reference to Figs. 9, 10A, 10B, and 10C.

[0082] The method 200, which may be performed by a CED (e.g., CED 800), comprises obtaining S210 a first delay configuration based on a beam configuration associated with one or more delay configurations to be applied by the CED. The first delay configuration is based on a reference point (e.g., reference point 50 and / or 50A) relative to the CED. The reference point may comprise a point on the CED. Or the reference point may comprise a point external to the CED. In one or more examples, the reference point is based on a location of a first wireless node and / or a second wireless node. The reference point may be one of the first wireless node or the second wireless node. The first wireless node and / or the second wireless node may be a CED controlling node, a wireless device, a user equipment, UE, an access point, or a global NodeB, gNB. The CED may be a reconfigurable intelligent surface, RIS.

[0083] In one or more examples, the method comprises obtaining S204 first information associated with a first direction of a first signal transmitted to the CED from the first wireless node and / or from the second wireless node. Additionally or alternatively, the method may comprise transmitting S202, from the CED to the first wireless node and / or the second wireless node, capability information that indicates the CED is configurable with the delay compensation configuration. The delay configuration may enable the first wireless node and / or the second wireless node to compensate for propagation delays associated with the CED.

[0084] The method may comprise receiving S206, from the first wireless node and / or the second wireless node, the beam configuration for the CED. In one or more examples, the method comprises establishing S808, at the CED, the beam configuration for the CED; the beam configuration may correspond to different positions of the first wireless node and / or the second wireless node in relation to the CED. In one or more examples, the method comprises transmitting S214, to the first wireless node and / or the second wireless node, capability signalling indicative of the delay configuration. The capability signalling indicative of the delay configuration may be transmitted S214A via a third wireless node to the first wireless node and / or the second wireless node. The capability signalling indicative of the delay configuration may comprise information associated with a lookup table that comprises the delay configuration. In one or more examples, the information associated with the lookup table comprises the lookup table. In one or more examples, the information associated with the lookup table comprises an index to, or configuration associated with, a value in the lookup table.

[0085] In one or more examples, the method comprises tuning S212 the CED based on the delay configuration and the first information.

[0086] It may be appreciated that any of the definitions and terms used in the description of Figs.

[0087] 1A-1B may also apply to the description of Fig. 2, Fig. 3, Fig. 4, Fig. 5, Figs. 6A-6C, Figs.

[0088] 7A-7B, Fig. 8, Fig. 9, and Figs. 10A-10C and vice versa. For example, any definitions and terms associated with the method performed by the wireless node (such as the first wireless node) and the wireless node itself disclosed herein may also apply and / or be used to the definitions and terms relating to the methods performed by the CED and the CED itself as disclosed herein and vice versa.

[0089] Fig. 4 is a block diagram of an example wireless node 300 according to the present disclosure. The wireless node 300 comprises memory circuitry 301, processor circuitry 302, and a wireless interface 303. The wireless node 300 may be configured to perform any of the methods disclosed and describe with reference to Fig. 3. In other words, the wireless node 300 may be configured for improving communication via a coverage enhancing device, CED, by using delay compensation. Wireless node 300 may also be referred to as a device or a wireless device. The wireless node 300 may be configured to communicate with another wireless device, such as the CED 800 disclosed herein, using a wireless communication system.

[0090] The wireless node 300 may be configured to transmit (such as via the wireless interface 303) to a CED 800 a beam configuration for the CED 800. The wireless node may be configured to perform a ranging operation based on a delay compensation from a CED. The wireless node 300 may be configured to receive (such as via the wireless interface 303), from a CED capability information that indicates the CED is configurable with a delay compensation configuration. The wireless node 300 may be further configured to obtain (such as via the wireless interface 303) first information associated with a first direction of a first signal transmitted to the CED. The wireless node 300 is configured to obtain (such as via the wireless interface 303 and / or from memory circuity 301) the delay configuration indicative of a first delay caused by a CED and associated with a beam configuration of the CED. The delay configuration enables the wireless node (such as first wireless node) and / or a second wireless node to compensate for propagation delays associated with the CED.

[0091] The wireless interface 303 is configured for wireless communications via a wireless communication system, such as a UWB system and / or a 3GPP system, such as a 3GPP system supporting one or more of: New Radio, NR, Narrow-band IoT, NB-IoT, and Long Term Evolution - enhanced Machine Type Communication, LTE-M, millimeter-wave communications, such as millimeter-wave communications in licensed bands, such as device-to-device millimeter-wave communications in licensed bands.

[0092] The wireless node 300 is optionally configured to perform any of the operations disclosed in Fig. 2 (such as any one or more of S102, S104, S106, S108A, S108B, S108C, S110). The operations of the wireless node 300 may be embodied in the form of executable logic routines (for example, lines of code, software programs, etc.) that are stored on a non-transitory computer readable medium (for example, memory circuitry 301) and are executed by processor circuitry 302).

[0093] Furthermore, the operations of the wireless node 300 may be considered a method that the wireless node 300 is configured to carry out. It will be understood that some examples of network node 400, as described with reference to Fig. 1 A, may likewise be configured to carry out such method(s). Also, while the described functions and operations may be implemented in software, such functionality may as well be carried out via dedicated hardware or firmware, or some combination of hardware, firmware and / or software.

[0094] Memory circuitry 301 may be one or more of a buffer, a flash memory, a hard drive, a removable media, a volatile memory, a non-volatile memory, a random-access memory (RAM), or another suitable device. In a typical arrangement, memory circuitry 301 may include a non-volatile memory for long term data storage and a volatile memory that functions as system memory for processor circuitry 302. Memory circuitry 301 may exchange data with processor circuitry 302 over a data bus. Control lines and an address bus between memory circuitry 301 and processor circuitry 302 also may be present (not shown in Fig. 4). Memory circuitry 301 is considered a non-transitory computer readable medium.

[0095] Memory circuitry 301 may be configured to store information (such as beam configuration information, delay configuration information, a lookup table, or the like) in a part of the memory.

[0096] Fig. 5 is a block diagram of an example CED 800 according to the disclosure. The CED 800 comprises memory circuitry 401, processor circuitry 402, and a wireless interface 403. The CED 800 may be configured to perform any of the methods disclosed in and described with reference to Fig. 3. In other words, the CED 800 may be configured for communication via the CED using delay compensation.

[0097] The CED 800 may be configured to communicate with a wireless node, such as the wireless nodes 300 and 300A disclosed herein, using a wireless communication system. The wireless interface 403 is configured for wireless communications via a wireless communication system, such as a UWB system and / or a 3GPP system supporting one or more of: New Radio, NR, Narrow-band IoT, NB-IoT, and Long Term Evolution - enhanced Machine Type Communication, LTE-M, millimeter-wave communications, such as millimeter-wave communications in licensed bands, such as device-to-device millimeter-wave communications in licensed bands.

[0098] The CED 800 is configured to obtain (such as via wireless interface 403 and / or using the processor circuitry 402) a first delay configuration based on a beam configuration associated with one or more delay configurations to be applied by the CED.

[0099] In one or more examples, the CED 800 is configured to (such as via wireless interface 403) transmit capability information that indicates the CED is configurable with the delay compensation configuration. In one or more examples, the CED 800 is configured to receive (such as via the wireless interface 403) the beam configuration for the CED. Additionally or alternatively, the CED 800 is configured to transmit (such as via wireless interface 403) capability signaling indicative of the delay compensation.

[0100] Processor circuitry 402 is optionally configured (such in combination with wireless interface 403) to perform any of the operations disclosed in Fig. 3 (such as any one or more of S204, S208, S212). The operations of the CED 800 may be embodied in the form of executable logic routines (for example, lines of code, software programs, etc.) that are stored on a non-transitory computer readable medium (for example, memory circuitry 401) and are executed by processor circuitry 402).

[0101] Furthermore, the operations of the CED 800 may be considered a method that the CED 800 is configured to carry out. Also, while the described functions and operations may be implemented in software, such functionality may as well be carried out via dedicated hardware or firmware, or some combination of hardware, firmware and / or software.

[0102] Memory circuitry 401 may be one or more of a buffer, a flash memory, a hard drive, a removable media, a volatile memory, a non-volatile memory, a random-access memory (RAM), or another suitable device. In a typical arrangement, memory circuitry 401 may include a non-volatile memory for long term data storage and a volatile memory that functions as system memory for processor circuitry 402. Memory circuitry 401 may exchange data with processor circuitry 402 over a data bus. Control lines and an address bus between memory circuitry 401 and processor circuitry 402 also may be present (not shown in Fig. 5). Memory circuitry 401 is considered a non-transitory computer readable medium.

[0103] Memory circuitry 401 may be configured to store information (such as beam configuration information, delay configuration information, a lookup table, or the like) in a part of the memory.

[0104] Figs. 6A-6C are diagrams illustrating examples of one or more CEDs, or one or more aspects of CEDs, according to this disclosure. Such examples depict delay configurations that may allow for compensation of propagation delays. For example, CED-induced propagation path often coexists with an LOS path; or in one or more examples, with a natural reflection path. In such examples, the CED-induced path may be time delayed to allow for alignment in time of signals at a receiver. Such delay may be implemented by means of physical measures applied to the elements or circuity of a CED.

[0105] Fig. 6A shows an example element CED 800A according to the disclosure with a normal or “no delay” configuration 602, and an example element CED 800B with the altered or “delay” configuration 604 having a long wire. CED 800A and CED 800B may be examples of CED 800 described with reference to the Figs. 1A, 1B, and 5, and as elsewhere disclosed herein. The length of this additional signal path may be equivalent to the difference in propagation distances, except that the speed of propagation may differ in free space and in, e.g., copper. However, introducing 10-50 meters of wires to CED elements may be challenging to implement and may not be a practical solution in many cases.

[0106] Moreover, with UWB and 3GPP systems, not all elements of a CED can be considered to have the same propagation delay. Further, the difference is propagation delay may be such that other solutions, including the approach shown in Fig. 6B, may be preferrable.

[0107] Figs. 6B and 6C show example elements of a CED 800C and CED 800D according to the disclosure, each with tunable delay 606 and 606A, respectively. CED 800C and CED 800D may be examples of CED 800 described with reference to Figs. 1A, 1B, and 5, and as elsewhere disclosed herein. As noted with reference to the example described in Figs.

[0108] 1A and 1B, the difference in propagation delay may be 0.77m. This would correspond to an additional delay line of approximately 0.385m, which may be possible to implement.

[0109] As noted above, the differences in propagation delay depend on the geometry. If a CED 800 beamforms to another direction (configurable through the parameters 0n), the propagation delays may change. Thus, it may desirable that the delay compensation is tunable. A CED element with L different delays is shown in Figs. 6B and 6C. The CED element may be tuned by configuration of the L - 1 switches. Once the reflection direction of the CED is determined, then the switch configuration can be configured, which In one or more examples, includes employing a look-up-table; thus, it may be implemented in a fashion complementary to determining other system parameters, such as phase shifts θn.

[0110] Delay lines of tunable delay 606 and or 606A, may be implemented in a variety of ways, including microstrip delay lines, lumped element delay line, surface acoustic wave, SAW, delay lines, or similar structure. Various use cases and design constraints may benefit from different implementations.

[0111] As disclosed herein, in one or more examples, a CED 800 may obtain a first delay configuration based on a beam configuration associated with one or more delay configurations to be applied by the CED 800. The CED may obtain first information associated with a first direction of a first signal transmitted to the CED 800 from the first wireless node and / or from the second wireless node. The CED 800 may tune itself (e.g., elements of the CED 800) based on the delay configuration and the first information. The delay configuration may enable the first wireless node and / or the second wireless node to compensate for propagation delays associated with the CED.

[0112] Figs. 7A is a signalling diagram illustrating example signalling 702 between example wireless nodes 300 and 300A, according to this disclosure. Wireless nodes 300 and 300A may be single antenna devices, which may be referred to as first and second wireless nodes, primary and second wireless devices, or the like, engaging in two-way ranging in which they establish the distance between them, which may be different from their relative positions. Wireless nodes 300 and 300A may be examples of wireless nodes 300 and 300A described with reference to the preceding figures.

[0113] In one or more examples, wireless node 300 transmits an initial signal 706, which may be referred to as a “poll” signal, at time Tsp. This poll is received at wireless node 300A at time TRP, which, after a fixed processing time, transmits a response signal 708 at time TSR towards wireless node 300. Wireless node 300 receives the response signal 708 at TRR, and transmits another, final signal 710 at time TSF, after a fixed processing time. Wireless node 300A receives the final signal 710 at time TRF. Wireless nodes 300 and 300A can then determine the distance between them using the equations:

[0114] Distance = T OF x (speed of light), and (5)

[0115]

[0116] These computations may not, however, hold or yield reliable results when a delay-compensating CED is present. For example, each element of a CED, such as a CED 800, may add a delay νn. The signal at receiving device, e.g., wireless node 300A, stemming from a transmitted signal from another device, e.g., wireless node 300 via a CED (not depicted in Fig. 7A) is thus:

[0117]

[0118] One benefit of introducing the delays νnis to align all signals β(t − τn− νn) in time. By way of example, τmax= maxnτnmay represent the largest delay across a CED and may represent the longest propagation distance between devices via any of the CED elements. In such cases, νnmay be understood as νn= τmax− τnto reach

[0119]

[0120] To maximize the SNR, the phase shifts may be understood as θn= 2nfcTmax, / n, which yields r(t) = αN exp(j2πfct)β(t — τmax). The entire CED may thus be seen as a single reflection point from the perspective of the receiving device. As such, a single reception time TRpfor the “poll” signal may be well defined. However, the difference TRP− TSPmay no longer correspond to the actual propagation time between devices (e.g., wireless nodes 300 and 300A). In fact, such propagation time may not even be well defined as every CED element may yield its own propagation time.

[0121] To resolve the situation, a reference point (e.g., reference point 50 or 50A as described with reference to the preceding figures) may be defined at, near, or associated with a CED. The reference point may be an antenna element of the CED, or it may be a different element that is between antenna elements, or it may be a different physical or intangible feature on the CED array. In some cases, the reference point is physically outside or external to the CED. A processing delay for this reference point may be defined as

[0122] Δ = τmax− τ1. (9) Quantity TRP− TSP- A represents the time of flight between devices via the CED, where the CED is treated as a single point located at the reference element. In such cases, a TOF may be calculated in a manner like Equation 6, above.

[0123] This is more apparent when considered with reference to Fig. 7B, which is a signalling diagram illustrating example signalling 712 between example wireless nodes 300 and 300A and CED 800, according to this disclosure. In one or more examples, the network node 400 and / or CED controlling node 700 may exchange signalling with CED 800. Fig.

[0124] 6B depicts a CED-assisted, two-way ranging protocol with corresponding computations in Equation 10.

[0125] In the example, wireless node 300 transmits an initial signal 720A, or “poll” signal, at time Tsp. This poll is reflected or relayed after a delay of A from CED 800 as initial signal 720B and received at wireless node 300A at time TRP, which, after a fixed processing time, transmits a response signal 722A at time TSR via CED 800 toward wireless node 300. The delay of A may be seen as and / or be associated with the first delay as described herein. CED 800 reflects or relays, after a delay of A, response signal 722B. Wireless node 300 receives the response signal 722B at TRR, and transmits another, final signal 724A at time TSF, after a fixed processing time. CED 800 reflects or relays, after a delay of A, final signal 724B. Wireless node 300A receives the final signal 724B at time TRF. Wireless nodes 300 and 300A can then determine the distance between them using the equations:

[0126] Distance = TOF x (speed of light), and (10)

[0127]

[0128] To utilize the TOF calculation of Equation 11 for positioning applications the value A must be known. But this value depends on the CED 800 geometry and the configured beam direction, as well as a reference point, and may be known only to certain devices within the system, such as the CED 800 or a CED controlling node. In certain scenarios this may not pose any issues. For example, in private networks, where the CED and other nodes are jointly installed, the value of A may be know. But in other applications, the devices may have no knowledge of the CED implementation wherefore A is not known without being communicated to other nodes in the system. Moreover, the value of A can be beam specific. When the CED beam changes, the associated value of A may also change. This may have consequences for positioning applications and may be addressed with certain system configurations or signaling protocols.

[0129] For example, Fig. 8 is a signalling diagram illustrating example signalling 802 between example wireless nodes 300 and 300A and an example CED 800, according to this disclosure. In one or more examples, the network node 400 and / or CED controlling node 700 may exchange signalling with CED 800.

[0130] Wireless node 300 may try to position another device, such as wireless node 300A. CED 800 is present in the environment, but wireless node 300 may have no prior information, or inaccurate prior information, about CED 800. CED 800 may transmit and wireless node 300 may receive capability signalling 804. Wireless node 300 may transmit, in response, and CED 800 may receive beam configuration signalling 806. CED 800 may transmit and wireless node 300 may receive delay configuration 808, which may be or include the value A described with reference to the prior figures. In one or more examples, delay configuration 808 may be referred to as signalling indicative of the delay configuration. In one or more examples, this includes obtaining information associated with a lookup table that comprises the delay configuration. In one or more examples, the information associated with the lookup table comprises the lookup table. In one or more examples, the information associated with the lookup table comprises an index to, or configuration associated with, a value in the lookup table.

[0131] Wireless node 300, wireless node 300A, and CED 800 may then exchange signaling or engage in a ranging or positioning process 810 as described above with reference to Fig.

[0132] 6B.

[0133] Whenever LOS is present between wireless node 300 and wireless node 300A, either or both devices may combine the LOS TOF and the CED-assisted TOF into an accurate position of the other device. Those skilled in the art will appreciate that without information of A on a per beam basis, the computation may be less precise as the ranging result for the CED path may be less accurate. The present disclosure thus provides solutions that share a delay configuration, A, on a per beam basis — e.g., a delay configuration that is based on a beam configuration. In one or more examples, wireless node 300 may transmit and CED 800 may receive beam configuration signalling 806A. This may be different from or updated relative to beam configuration signalling 806. In response, CED 800 may transmit and wireless node 300 may receive delay configuration 808A. This signaling exchange may be referred to as signaling indicative of a delay or signaling indicative of a delay configuration; or it may be referred to as signaling indicative of another delay, a different delay, or a second delay, in various examples.

[0134] In the event of a signaling exchange or protocol execution that employs signalling 806A and 808A, wireless nodes 300 and 300A, and CED 800 may then exchange signaling or engage in another ranging or positioning process 810A as described above with reference to Fig. 6B.

[0135] Elements of CEDs, such as CED 800 described with reference to the preceding figures, may experience different delays (in relation to the reciprocal of the baseband bandwidth), which may be an advantage in some cases. A CED 800 may offer a beamforming power gain of N2. According to the present disclosure, additional benefits, such as a further beamforming gain, may also be available from a delay-compensating CED 800.

[0136] By way of example, for a signal β(t) acting as a synchronization signal, a receiver or receiving device, such as wireless node 300, may seek to determine when (and if) the transmitter, such as wireless node 300A, has transmitted signal

[0137]

[0138] After a down conversion to baseband, wireless node 300 may perform a correlation between the received baseband signal and β(t).

[0139]

[0140] Ignoring noise and the path loss a, the output of the correlator may thus be

[0141]

[0142] In systems for which the narrowband assumption is valid

[0143]

[0144] The receiver, such as wireless node 300, may analyze the signal pNB(t) and determine that a signal is present at time t = t0, where

[0145] t0= arg maxtρNB(t) (15)

[0146] if IPNB(^O) I > T. From the Cauchy-Schwarz inequality, it readily follows that a maximum of PNBC occurs at t = T. Thus, according to the present disclosure, error performance of this detector, may be understood as: (i) the beamforming gain (represented by the sum in the expression for pNB(t)), and (ii) the sharpness of the function 2(t). As the function 2(t) is not impacted by the number of RIS elements, N, it follows that the SNR experiences a “single” beamforming effect, namely, that from the sum.

[0147] In another example, a double beamforming is possible, including when CED 800 beamforming weights are fixed and targets a specific location in physical space. The receiver, such as wireless node 300, may be located at a position such that pNB(t) = 2(t - T N. For a perturbation of the receiver’s position; this alters the delays Tninto variables tn. As the variable 0nremains constant, it follows that

[0148]

[0149] where N is beamforming gain at the new position, and where |tv| < N. Further, since 0n= 27ifcTn, it is observed that

[0150]

[0151] Error performance may thus be a function of the beamforming gain N and the sharpness of 2(t), which may hold regardless of the receiver’s location.

[0152] With CED 800 delays, as disclosed herein, other benefits may be realized. After the perturbation, for example,

[0153]

[0154] As noted above, since θn= 2πfcτmax, ∀n, this reduces to

[0155]

[0156] The skilled person will thus recognize that Equation 19 represents a double beamforming effect, which may be advantageous. For example, when the receiver, such as wireless node 300, is not in the location of the CED 800 beam, the correlation properties of the signal-pulse β(t) may change. Complex exponentials, which describe the traditional beamforming effect, may remain unaltered compared with the narrow band assumption. But unlike the narrowband assumption, there is not a unique time point where all signalpulses 2(-) are aligned. Thus, the magnitude of PRisdeiayC is in general smaller than that of PNBC whenever the receiver is not at the exact center of the RIS beam. Producing a desired effect in one or more examples.

[0157] For example, in applications where the system should determine whether or not a device is in an exact spot, it may be beneficial that the statistic forming the basis of the detection peaks when the device is at the spot and reduces sharply whenever it is not. With the narrowband assumption, the beamforming effect accomplishes this, and with CED delays, there is an additional effect that the signal-pulses λ(·) are misaligned outside of the RIS beam center, which is a beneficial technical effect. Fig. 9 is a diagram illustrating an example wireless communication system 3 comprising examples of a wireless node 300 and an example CED 800 according to this disclosure. In the system 3, wireless node 300 is located about 8 meters from the center of CED 800, which may be, for example, a 41-element CED 800 that spans 1.2 meters. CED 800 may have a reference point 50, which may be on or external to the CED 800. CED 800 may be separated from wireless node 300 by a blockage 902, which may represent a barrier, a person or people, or some other LOS obstruction. In the example, system 3 is in a room that is 9 meters long where the CED 800 is 2 meters above the floor. CED 800 is positioned about 7 meters away from wireless node 300. Wireless node 300 may transmit or receive a signal on wireless link 10, which may have a 5GHz carrier frequency with 500MHz bandwidth. CED 800 may reflect or relay signals as wireless links 10A.

[0158] According to the example, the beamforming configuration of CED 800 is set to point downwards. A user may be assumed to move along the axis x0along the floor. For example, a user may move from a position 7 meters from wireless node 800 to a position 9 meters from CED 800. In doing so, the user will pass by the CED 800 center, which is about 8 meters from wireless node 300.

[0159] Functions ρ(t) and ρRISdelay(t) may be calculated using Equations 12 and 18 to determine performance for a CED 800 with and without delay, respectively. Doing so, it is readily observable that performance of a CED 800 without delay is reduced as compared to CED 800 with delay.

[0160] Figs. 10A-10C are plots illustrating examples of one or more advantages, such as those described with reference to Fig. 9, of wireless nodes and / or CEDs operating according to this disclosure. For example, the double beamforming effect is visible by comparing the sidelobes of plots 1000A and 1000B, respectively. The more pronounced main peak indicates better performance in detecting when a user is exactly under the CED 800. Plot 1000C depicts a relatively reduced performance compared with a delay-compensating CED according to the present disclosure. Thus, for ranging and positioning applications, advantages of the present disclosure are observable by comparing plots 1000A and 1000C, and the peak in plot 1000A is less prone to noise, as indicated by the relatively higher curvature. Embodiments of methods and products (e.g., wireless nodes and CED) according to the disclosure are set out in the following items:

[0161] Item 1. A method, performed by a first wireless node, for improving communication via a coverage enhancing device, CED, by using delay compensation, the method comprising:

[0162] obtaining a delay configuration indicative of a first delay caused by the CED and associated with a beam configuration of the CED,

[0163] wherein the delay configuration enables the first wireless node and / or a second wireless node to compensate for propagation delays associated with the CED.

[0164] Item 2. The method of item 1, wherein the delay configuration is associated with a reference point relative to the CED.

[0165] Item 3. The method of item 2, wherein the reference point comprises a point on the CED.

[0166] Item 4. The method of item 2, wherein the reference point comprises a point external to the CED.

[0167] Item 5. The method of item 4, wherein the reference point is based on a location of a second wireless node.

[0168] Item 6. The method of any of items 4 or 5, wherein the reference point is the second wireless node.

[0169] Item 7. The method of any of the preceding items, the method comprising obtaining first information associated with a first direction of a first signal transmitted to the CED from the first wireless node and / or from the second wireless node.

[0170] Item 8. The method of any of the preceding items, the method comprising performing a ranging operation based on the delay configuration.

[0171] Item 9. The method of any of the preceding items, the method comprising receiving, from the CED, capability information that indicates the CED is configurable with the delay compensation configuration. Item 10. The method of any of the preceding items, the method comprising transmitting to the CED the beam configuration for the CED.

[0172] Item 11. The method of any of the preceding items, wherein obtaining the delay configuration comprises receiving, from the CED, signalling indicative of the delay configuration.

[0173] Item 12. The method of any of items 1-10, wherein obtaining the delay configuration comprises retrieving the delay configuration from memory of the first wireless device.

[0174] Item 13. The method of any of the items 11 or 12, wherein obtaining the delay configuration comprises obtaining information associated with a lookup table that comprises the delay configuration.

[0175] Item 14. The method of item 13, wherein the information associated with the lookup table comprises the lookup table.

[0176] Item 15. The method of item 13, wherein the information associated with the lookup table comprises an index to, or configuration associated with, a value in the lookup table.

[0177] Item 16. The method of any of the preceding items, wherein the first wireless node and / or the second wireless node is a CED controlling node, a wireless device, an access point, or a radio access network node.

[0178] Item 17. The method of any of the preceding items, wherein the CED is a reconfigurable intelligent surface, RIS.

[0179] Item 18. A method performed by a coverage enhancing device, CED, for communication via the CED using delay compensation, the method comprising:

[0180] obtaining a first delay configuration based on a beam configuration associated with one or more delay configurations to be applied by the CED.

[0181] Item 19. The method of item 18, wherein the first delay configuration is based on a reference point relative to the CED. Item 20. The method of item 19, wherein the reference point comprises a point on the CED.

[0182] Item 21. The method of item 19, wherein the reference point comprises a point external to the CED

[0183] Item 22. The method of item 21, wherein the reference point is based on a location of a first wireless node and / or a second wireless node.

[0184] Item 23. The method of any of items 21 or 22, wherein the reference point is one of the first wireless node or the second wireless node.

[0185] Item 24. The method of any of items 18-23, the method comprising obtaining first information associated with a first direction of a first signal transmitted to the CED from the first wireless node and / or from the second wireless node.

[0186] Item 25. The method of any of items 18-24, the method comprising tuning the CED based on the delay configuration and the first information.

[0187] Item 26. The method of any of items 18-25, the method comprising transmitting, from the CED to the first wireless node and / or the second wireless node, capability information that indicates the CED is configurable with the delay compensation configuration.

[0188] Item 27. The method of any of items 18-26, wherein the delay configuration enables the first wireless node and / or the second wireless node to compensate for propagation delays associated with the CED.

[0189] Item 28. The method of any of items 18-27, the method comprising establishing, at the CED, the beam configuration for the CED, wherein the beam configuration corresponds to different positions of the first wireless node and / or the second wireless node in relation to the CED.

[0190] Item 29. The method of any of items 18-28, the method comprising receiving, from the first wireless node and / or the second wireless node, the beam configuration for the CED. Item 30. The method of any of items 18-29, the method comprising transmitting, to the first wireless node and / or the second wireless node, capability signalling indicative of the delay configuration.

[0191] Item 31. The method of item 30, wherein the capability signalling indicative of the delay configuration is transmitted via a third wireless node to the first wireless node and / or the second wireless node.

[0192] Item 32. The method of item 31, wherein the capability signalling indicative of the delay configuration comprises information associated with a lookup table that comprises the delay configuration.

[0193] Item 33. The method of item 32, wherein the information associated with the lookup table comprises the lookup table.

[0194] Item 34. The method of any of items 32 or 33, wherein the information associated with the lookup table comprises an index to, or configuration associated with, a value in the lookup table.

[0195] Item 35. The method of any of items 22-34, wherein the first wireless node and / or the second wireless node is a CED controlling node, a wireless device, a user equipment, UE, an access point, or a global NodeB, gNB.

[0196] Item 36. The method of any of items 18-34, wherein the CED is a reconfigurable intelligent surface, RIS.

[0197] Item 37. A wireless node comprising memory circuitry, processor circuitry, and a wireless interface, wherein the wireless node is configured to perform any of the methods according to any of items 1 -17.

[0198] Item 38. A coverage enhancing device, CED, comprising memory circuitry, processor circuitry, and a wireless interface, wherein the CED is configured to perform any of the methods according to any of items 18-36.

[0199] The use of the terms “first”, “second”, “third” and “fourth”, “primary”, “secondary”, “tertiary” etc. does not imply any particular order, but are included to identify individual elements. Moreover, the use of the terms “first”, “second”, “third” and “fourth”, “primary”, “secondary”, “tertiary” etc. does not denote any order or importance, but rather the terms “first”, “second”, “third” and “fourth”, “primary”, “secondary”, “tertiary” etc. are used to distinguish one element from another. Note that the words “first”, “second”, “third” and “fourth”, “primary”, “secondary”, “tertiary” etc. are used here and elsewhere for labelling purposes only and are not intended to denote any specific spatial or temporal ordering. Furthermore, the labelling of a first element does not imply the presence of a second element and vice versa.

[0200] It may be appreciated that the figures comprise some circuitries or operations which are illustrated with a solid line and some circuitries, components, features, or operations which are illustrated with a dashed line. Circuitries or operations which are comprised in a solid line are circuitries, components, features or operations which are comprised in the broadest example. Circuitries, components, features, or operations which are comprised in a dashed line are examples which may be comprised in, or a part of, or are further circuitries, components, features, or operations which may be taken in addition to circuitries, components, features, or operations of the solid line examples. It should be appreciated that these operations need not be performed in order presented.

[0201] Furthermore, it should be appreciated that not all of the operations need to be performed. The example operations may be performed in any order and in any combination. It should be appreciated that these operations need not be performed in order presented.

[0202] Circuitries, components, features, or operations which are comprised in a dashed line may be considered optional.

[0203] Other operations that are not described herein can be incorporated in the example operations. For example, one or more additional operations can be performed before, after, simultaneously, or between any of the described operations.

[0204] Certain features discussed above as separate implementations can also be implemented in combination as a single implementation. Conversely, features described as a single implementation can also be implemented in multiple implementations separately or in any suitable sub-combination. Moreover, although features may be described above as acting in certain combinations, one or more features from a claimed combination can, in some cases, be excised from the combination, and the combination may be claimed as any subcombination or variation of any sub-combination.

[0205] It is to be noted that the word "comprising" does not necessarily exclude the presence of other elements or steps than those listed. It is to be noted that the words "a" or "an" preceding an element do not exclude the presence of a plurality of such elements.

[0206] It is to be noted that the term "indicative of may be seen as “associated with”, “related to”, “descriptive of’, “characterizing”, and / or “defining”. The terms “indicative of”, “associated with”, “related to”, “descriptive of”, “characterizing”, and “defining” can be used interchangeably. The term “indicative of” can be seen as indicating a relation. For example, weight data indicative of weight may comprise one or more weight parameters. It is to be noted that the word "based on" may be seen as “as a function of” and / or “derived from”. The terms “based on” and “as a function of” can be used interchangeably. For example, a parameter determined “based on” a data set can be seen as a parameter determined “as a function of’ the data set. In other words, the parameter may be an output of one or more functions with the data set as an input.

[0207] A function may be characterizing a relation between an input and an output, such as mathematical relation, a database relation, a hardware relation, logical relation, and / or other suitable relations.

[0208] It should further be noted that any reference signs do not limit the scope of the claims, that the example embodiments may be implemented at least in part by means of both hardware and software, and that several "means", "units" or "devices" may be represented by the same item of hardware.

[0209] The various example methods, devices, nodes and systems described herein are described in the general context of method steps or processes, which may be implemented in one aspect by a computer program product, embodied in a computer-readable medium, including computer-executable instructions, such as program code, executed by computers in networked environments. A computer-readable medium may include removable and non-removable storage devices including, but not limited to, Read Only Memory (ROM), Random Access Memory (RAM), compact discs (CDs), digital versatile discs (DVD), etc. Generally, program circuitries may include routines, programs, objects, components, data structures, etc. that perform specified tasks or implement specific abstract data types. Computer-executable instructions, associated data structures, and program circuitries represent examples of program code for executing steps of the methods disclosed herein. The particular sequence of such executable instructions or associated data structures represents examples of corresponding acts for implementing the functions described in such steps or processes.

[0210] Although features have been shown and described, it will be understood that they are not intended to limit the claimed disclosure, and it will be made obvious to those skilled in the art that various changes and modifications may be made without departing from the scope of the claimed disclosure. The specification and drawings are, accordingly, to be regarded in an illustrative rather than restrictive sense. The claimed disclosure is intended to cover all alternatives, modifications, and equivalents.

Claims

CLAIMS1. A method, performed by a first wireless node, for improving communication via a coverage enhancing device, CED, by using delay compensation, the method comprising:obtaining a delay configuration indicative of a first delay caused by the CED and associated with a beam configuration of the CED,wherein the delay configuration enables the first wireless node and / or a second wireless node to compensate for propagation delays associated with the CED.

2. The method of claim 1, wherein the delay configuration is associated with a reference point relative to the CED.

3. The method of claim 2, wherein the reference point comprises a point on the CED.

4. The method of claim 2, wherein the reference point comprises a point external to the CED; and / or wherein the reference point is based on a location of a second wireless node.

5. The method of any of the preceding claims, the method comprising obtaining first information associated with a first direction of a first signal transmitted to the CED from the first wireless node and / or from the second wireless node.

6. The method of any of the preceding claims, the method comprising performing a ranging operation based on the delay configuration.

7. The method of any of the preceding claims, the method comprising receiving, from the CED, capability information that indicates that the CED is configurable with the delay compensation configuration.

8. The method of any of the preceding claims, the method comprising transmitting to the CED the beam configuration for the CED.

9. The method of any of the preceding claims, wherein obtaining the delay configuration comprises:- receiving, from the CED, signalling indicative of the delay configuration; and / orretrieving the delay configuration from memory of the first wireless device; and / orwherein obtaining the delay configuration comprises obtaining information associated with a lookup table that comprises the delay configuration.

10. The method of claim 9, wherein the information associated with the lookup table comprises the lookup table, or an index to, or configuration associated with, a value in the lookup table.

11. The method of any of the preceding claims, wherein the first wireless node and / or the second wireless node is a CED controlling node, a wireless device, an access point, or a radio access network node.

12. The method of any of the preceding claims, wherein the CED is a reconfigurable intelligent surface, RIS.

13. A method performed by a coverage enhancing device, CED, for communication via the CED using delay compensation, the method comprising:obtaining a first delay configuration based on a beam configuration associated with one or more delay configurations to be applied by the CED.

14. The method of claim 13, wherein the first delay configuration is based on a reference point relative to the CED.

15. The method of claim 14, wherein the reference point comprises a point on the CED.

16. The method of claim 14, wherein the reference point comprises a point external to the CED; and / or wherein the reference point is based on a location of a first wireless node and / or a second wireless node.

17. The method of any of claims 13-16, the method comprising obtaining first information associated with a first direction of a first signal transmitted to the CED from the first wireless node and / or from the second wireless node.

18. The method of any of claims 13-17, the method comprising tuning the CED based on the delay configuration and the first information.

19. The method of any of claim 13-18, the method comprising transmitting, from the CED to the first wireless node and / or the second wireless node, capability information that indicates the CED is configurable with the delay compensation configuration, wherein the delay configuration enables the first wireless node and / or the second wireless node to compensate for propagation delays associated with the CED.

20. The method of any of claims 13-19, the method comprising:receiving, from the first wireless node and / or the second wireless node, a beam configuration for the CED; wherein the beam configuration corresponds to different positions of the first wireless node and / or the second wireless node in relation to the CED; and / ortransmitting, to the first wireless node and / or the second wireless node, capability signalling indicative of the delay configuration.

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