Apparatus and method for radio frequency front end tuning

Abstract

Embodiments of the present disclosure relate to a user equipment apparatus, method, and computer program for RF front end tuning. The UE apparatus comprises a tunable radio frequency (RF) front end (100), an observation receive system (117) configured to detect a property of an aggressor signal which drives the tunable RF front end into compression, and a correlator (114) configured to identify an aggressor signal pattern of the detected aggressor signal based on the detected property of the aggressor signal, and tune, based on the identified aggressor signal pattern, the tunable RF front end to suppress an interference of the aggressor signal with the tunable RF front end.

Description

APPARATUS AND METHOD FOR RADIO FREQUENCY FRONT END TUNING FIELD

[0001] Embodiments of the present disclosure generally relate to the field of wireless communication, and in particular to a device, method, and a computer program for radio frequency (RF) front end tuning.BACKGROUND

[0002] A communication network can be seen as a facility that enables communications between two or more communication devices, or provides communication devices access to a data network. A mobile or wireless communication network is one example of a communication network.

[0003] Such communication networks operate in accordance with standards, such as those promulgated by third generation partnership project (3 GPP) or European telecommunications standards institute (ETSI). Examples of such standards include the so-called 5th generation (5G) standard, 6th generation (6G), or other standards promulgated by 3 GPP.

[0004] Current modulation and coding schemes as defined in 3 GPP are not designed to be robust against non-linear effects in an RF hardware, which will contribute significantly to received signal quality, for example received signal to interference plus noise ratio (SINR) and error vector magnitude (EVM).SUMMARY

[0005] In general, example embodiments of the present disclosure provide devices, methods and a computer program for RF front end tuning.

[0006] In a first aspect, there is provided a user equipment (UE) apparatus. The UE apparatus comprises: a tunable radio frequency (RF) front end, an observation receive system configured to detect a property of an aggressor signal which drives the tunable RF front end into compression, and a correlator configured to identify an aggressor signal pattern of the detected aggressor signal based on the detected property of the aggressor signal, and tune, based on the identified aggressor signal pattern, the tunable RF front end to suppress an interference of the aggressor signal with the tunable RF front end.

[0007] In some embodiments, the observation receive system comprises a phase detector configured to detect a phase of the aggressor signal and an envelope detector for an envelope of the aggressor signal.

[0008] In some embodiments, the observation receive system comprises a wide band linear receiver.

[0009] In some embodiments, the correlator is configured to identify the aggressor signal pattern based on at least one of at least one pre-determined aggressor signal pattern; or a learning algorithm based on machine learning or artificial intelligence.

[0010] In some embodiments, the UE apparatus further comprises a baseband control system and wherein the at least one of the pre-determined aggressor signal patterns or the learning algorithm is programed or re-programed by the baseband control system.

[0011] In some embodiments, the aggressor signal is sensed via a coupler, wherein the coupler is connected to or within the tunable RF front end, a forward coupling path of the coupler is connected with observation receive system, a non-coupled path of the coupler is connected with the baseband control system.

[0012] In some embodiments, the UE apparatus further comprises a feedback receiver with an output terminal connected to the baseband control system, wherein the forward coupling path of the coupler is connected to an input terminal of the observation receive system and an input terminal of the feedback receiver via a power splitter.

[0013] In some embodiments, the UE apparatus further comprises a first selective switch with two terminals connected to an output of the phase detector and the non-coupled path of the coupler respectively and one terminal connected to a first input terminal of the baseband control system.

[0014] In some embodiments, the first selective switch is controlled by a control signal, wherein the control signal is dependent on an output of the envelope detector.

[0015] In some embodiments, the baseband control system comprises an analog-to-digital converter (ADC) or a RF transceiver connected to the first input terminal of the baseband control system, wherein the ADC is controlled by the control signal.

[0016] In some embodiments, the value of the control signal is determined based on whether the output of the envelope detector is above a predetermined threshold provided by the baseband control system.

[0017] In some embodiments, the value of the control signal is further dependent on at least one of an enable signal and a disable signal from the baseband control system, wherein the enablesignal is able to set the control signal to logical 1 and the disable signal is able to set the control signal to logical 0.

[0018] In some embodiments, an output terminal of the envelope detector is further connected to a second input terminal of the baseband control system, and an output of the envelope detector is used for a machine learning or artificial intelligence algorithm to identify the aggressor signal pattern.

[0019] In some embodiments, the wide band linear receiver is selectively connected to the coupler or a second front end via a second selective switch.

[0020] In a second aspect, there is provided a method implemented at a UE apparatus, wherein the UE apparatus comprises: a tunable radio frequency (RF) front end, an observation receive system, and a correlator, wherein the method comprises: detecting, by the observation receive system, a property of an aggressor signal which drives the tunable RF front end into compression; identifying, by the correlator, an aggressor signal pattern of the detected aggressor signal based on the detected property of the aggressor signal; and tuning, based on the identified aggressor signal pattern, the tunable RF front end to suppress an interference of the aggressor signal with the tunable RF front end.

[0021] In a third aspect, there is provided a computer program. The computer program comprises instructions which, when executed by an apparatus, cause the apparatus to perform the method according to the second aspect above.

[0022] In a fourth aspect, there is provided a non-transitory computer readable medium. The non-transitory computer readable medium comprises program instructions for causing the user equipment apparatus at least to perform the method according to the second aspect above.

[0023] It is to be understood that the summary section is not intended to identify key or essential features of embodiments of the present disclosure, nor is it intended to be used to limit the scope of the present disclosure. Other features of the present disclosure will become easily comprehensible through the following description.BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Some embodiments will now be described with reference to the accompanying drawings, in which:

[0025] Fig. 1 A illustrates an example network environment in which some embodiments of the present disclosure can be implemented;

[0026] Fig. 1B illustrates examples of devices and infrastructure that may make use of wireless interfaces of different kind potentially connected to a UE;

[0027] Fig. 2 illustrates an example circuit for RF front end tuning according to some embodiments of the present disclosure;

[0028] Fig. 3 illustrates an example circuit for RF front end tuning according to some embodiments of the present disclosure;

[0029] Fig. 4 illustrates an example circuit for RF front end tuning according to some embodiments of the present disclosure;

[0030] Fig. 5 illustrates a flowchart of a method implemented at a network device according to some embodiments of the present disclosure;

[0031] Fig. 6 illustrates a simplified block diagram of an apparatus that is suitable for implementing embodiments of the present disclosure; and

[0032] Fig. 7 illustrates a block diagram of an example computer readable medium in accordance with some embodiments of the present disclosure.

[0033] Throughout the drawings, the same or similar reference numerals represent the same or similar elements.DETAILED DESCRIPTION

[0034] Principles of the present disclosure will now be described with reference to some example embodiments. It is to be understood that these embodiments are described only for the purpose of illustration and help those skilled in the art to understand and implement the present disclosure, without suggesting any limitation as to the scope of the disclosure. The disclosure described herein can be implemented in various manners other than the ones described below.

[0035] In the following description and claims, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skills in the art to which this disclosure belongs.

[0036] References in the present disclosure to “one embodiment,” “an embodiment,” “an example embodiment,” and the like indicate that the embodiment described may include a particular feature, structure, or characteristic, but it is not necessary that every embodiment includes the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, orcharacteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

[0037] It shall be understood that although the terms “first” and “second” etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and similarly, a second element could be termed a first element, without departing from the scope of example embodiments. As used herein, the term “and / or” includes any and all combinations of one or more of the listed terms.

[0038] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises”, “comprising”, “has”, “having”, “includes” and / or “including”, when used herein, specify the presence of stated features, elements, and / or components etc., but do not preclude the presence or addition of one or more other features, elements, components and / or combinations thereof. As used herein, “at least one of the following: ” and “at least one of ” and similar wording, where the list of two or more elements are joined by “and” or “or”, mean at least any one of the elements, or at least any two or more of the elements, or at least all the elements.

[0039] As used in this application, the term “circuitry” may refer to one or more or all of the following:(a) hardware-only circuit implementations (such as implementations in only analog and / or digital circuitry) and(b) combinations of hardware circuits and software, such as (as applicable):(i) a combination of analog and / or digital hardware circuit(s) with software / firmware and(ii) any portions of hardware processor(s) with software (including digital signal processor(s)), software, and memory(ies) that work together to cause an apparatus, such as a mobile phone or server, to perform various functions) and(c) hardware circuit(s) and or processor(s), such as a microprocessor s) or a portion of a microprocessor(s), that requires software (e.g., firmware) for operation, but the software may notbe present when it is not needed for operation.

[0040] This definition of circuitry applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or portion of a hardware circuit or processor and its (or their) accompanying software and / or firmware. The term circuitry also covers, for example and if applicable to the particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in server, a cellular network device, or other computing or network device.

[0041] As used herein, the term “communication network” refers to a network following any suitable communication standards, such as long term evolution (LTE), LTE-advanced (LTE-A), wideband code division multiple access (WCDMA), high-speed packet access (HSPA), narrow band internet of things (NB-IoT) and so on. Furthermore, the communications between a terminal device and a network device in the communication network may be performed according to any suitable generation communication protocols, including, but not limited to, the first generation (1G), the second generation (2G), 2.5G, 2.75G, the third generation (3G), the fourth generation (4G), 4.5G, the future fifth generation (5G) communication protocols, and / or any other protocols either currently known or to be developed in the future. Embodiments of the present disclosure may be applied in various communication systems. Given the rapid development in communications, there will of course also be future type communication technologies and systems with which the present disclosure may be embodied. It should not be seen as limiting the scope of the present disclosure to only the aforementioned system.

[0042] As used herein, the term “network device” refers to a node in a communication network via which a terminal device accesses the network and receives services therefrom. The network device may refer to a base station (BS) or an access point (AP), for example, a node B (NodeB or NB), an evolved NodeB (eNodeB or eNB), a NRNB (also referred to as a gNB), a remote radio unit (RRU), a radio header (RH), a remote radio head (RRH), a relay, a low power node such as a femto, a pico, and so forth, depending on the applied terminology and technology.

[0043] As used herein, the term “terminal device” refers to any end device that may be capable of wireless communication. By way of example rather than limitation, a terminal device may also be referred to as a communication device, user equipment (UE), a subscriber station (SS), a portable subscriber station, a mobile station (MS), or an access terminal (AT). The terminal device may include, but not limited to, a mobile phone, a cellular phone, a smart phone, voice over IP (VoIP) phones, wireless local loop phones, a tablet, a wearable terminal device, a personaldigital assistant (PDA), portable computers, desktop computer, image capture terminal devices such as digital cameras, gaming terminal devices, music storage and playback appliances, vehiclemounted wireless terminal devices, wireless endpoints, mobile stations, laptop-embedded equipment (LEE), laptop-mounted equipment (LME), USB dongles, smart devices, wireless customer-premises equipment (CPE), an Internet of Things (loT) device, a watch or other wearable, a head-mounted display (HMD), a vehicle, a drone, a medical device and applications (e.g., remote surgery), an industrial device and applications (e.g., a robot and / or other wireless devices operating in an industrial and / or an automated processing chain contexts), a consumer electronics device, a device operating on commercial and / or industrial wireless networks, and the like. In the following description, the terms “terminal device”, “communication device”, “terminal”, “user equipment” and “UE” may be used interchangeably.

[0044] Principles and embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings.

[0045] Reference is first made to Fig. 1A, which illustrates an example communication system 100A in which embodiments of the present disclosure may be implemented. The system 100A includes a network device 110. The network device 110 serves an area 130 (also called as cell 130). The system 100A also includes one or more terminal devices, such as terminal devices 120, 121. The terminal devices 120, 121 are capable of connecting and communicating in an uplink (UL) and a downlink (DL) with the network device 110. In communication systems, an UL refers to a link in a direction from a terminal device to a network device, and a DL refers to a link in a direction from the network device to the terminal device.

[0046] It is to be understood that the terminal devices 120, 121 may implement the solution as proposed in the present disclosure and function as the UE apparatus as disclosed herein.

[0047] It is also to be understood that the number of network device and terminal devices is only for the purpose of illustration without suggesting any limitations. The system 100 A may include any suitable number of network device and terminal devices adapted for implementing embodiments of the present disclosure.

[0048] Communications in the communication system 100 A may be implemented according to any proper communication protocol(s), comprising, but not limited to, cellular communication protocols of the first generation (1G), the second generation (2G), the third generation (3G), the fourth generation (4G) and the fifth generation (5G) and on the like, wireless local network communication protocols such as Institute for electrical and electronics engineers (IEEE) 802.11 and the like, and / or any other protocols currently known or to be developed in the future.Moreover, the communication may utilize any proper wireless communication technology, comprising but not limited to: code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), frequency division duplex (FDD), time division duplex (TDD), multiple-input multiple-output (MIMO), orthogonal frequency division multiple (OFDM), discrete fourier transform spread OFDM (DFT-s-OFDM) and / or any other technologies currently known or to be developed in the future.

[0049] With advance of 5G and upcoming 6G, several new enhancements have been identified in a scenario wherein a potential victim receiver could be hit with a strong interference arising from intermodulation products and adjacent channel interference (ACI) from a transmitter which is placed in close vicinity to a victim receiver and thus further enhancements are required.

[0050] In addition, simultaneous use of Wi-Fi or similar systems that make use of spectrum adjacent to licensed spectrum allocated to 3GPP is expected to be more frequently used in the future due to evolution of applications like augmented reality, video calls, online gaming as well as applications and wireless interfaces related to it.

[0051] The transmitter and receiver can be within same device as is a case of gNB operating in sub-band full duplex (SBFD) mode or they can be two different devices as is a case of side link or two UEs in SBFD mode. The same physical problem arises in RF front ends for use cases where use of adjacent industrial, scientific, and medical (ISM) band causes interference to 3 GPP bands as a frequency separation is not sufficient to enable practical RF isolation using filters.

[0052] Furthermore, future use of higher order modulation and wider bandwidth as envisioned for 6G as well as for future Wi-Fi standards make the problem more challenging.

[0053] Reference is now made to Fig. IB, which illustrates examples of devices and infrastructure that make use of wireless interfaces of different kind potentially connected to a UE or interconnected between any. In wireless communication systems, various system entities serve as primary master communication link between the network infrastructure and UEs, such as smartphones, tablets, and other connected devices. These entities manage network access, signal routing, data transmission, and overall connectivity.

[0054] Various system entities in current and future wireless communication systems that controls the UEs may include for example, next-generation NodeB (xgNB) in 6G networks; enhanced Wi-Fi networks (Wi-Fi 7 / 8); integrated access and backhaul (IAB) networks: cloud-edge Integration, etc.

[0055] UE’s RF performance related to its robustness to interference generated due tointermodulation is according to 3GPP, tested with unwanted signal levels of -46 dBm, while a wanted signal for some bands is set to about -91 dBm. Legacy devices can therefore not be expected to function properly if adjacent power from interfering signals is above -46 dBm within a few dB. Other 3 GPP requirements seem to imply that linearity can be expected in case a signal level of -25 dBm is present at the receiver; however, in case the nature of such signal can cause 3rd order intermodulation products, expected de-sense can be high and likely be more than 60 dB.

[0056] RF components, like mixers and amplifiers, typically have much higher third order intermodulation intercept point than compression point, that is IIP3 and 1-dB compression point. For this reason, the numbers above make a lot of sense (-25 dBm & -46 dBm) as it correctly reflects real physical behavior.

[0057] Base band receive circuitry only measures and detects in-band signals. For this reason, it is not possible to determine if received in-band noise and distortion is caused by:• High order intermodulation products due to strong RF signals in adjacent spectrum. • In-band noise from adjacent systems, harmonics, or noise due to out of band aggressor noise floor.• adjacent channel leakage ratio (ACLR) contributions from transmitters using adjacent spectrum.

[0058] Linear reception may not be possible if there is clear interfering component caused by some of the above effects. Baseband circuitry and RF drivers are in such cases not able to determine if the RF front end circuitry is driven in compression causing gain and noise figure compression or if the problem is caused by strong RF signals in adjacent spectrum that cause intermodulation distortion (IMD) products that falls directly into the wanted band.

[0059] Some analogue tuning and RF isolation means have been developed to deal with and enhance RF isolation; however, there is not any intelligent metric to tune yet. Tuning adaptable antenna systems or analogue tunable self-interference cancellation (SIC) hardware require accurate knowledge about the signal characteristics and root cause of the interference that causes the problem. The parameters and means described in the existing standards do not seem to be sufficient to solve the problem in an efficient way.

[0060] Among others, an issue addressed by some embodiments of the present disclosure is how to identify an aggressor that cause interference and mitigate the interference based on the identified aggressor.

[0061] According to embodiments of the present disclosure, there is provided a UE apparatus for RF front end tuning. In an aspect of the UE apparatus, the UE apparatus comprises a tunable radio frequency (RF) front end, an observation receive system configured to detect a property of an aggressor signal which drives the tunable RF front end into compression, and a correlator configured to identify an aggressor signal pattern of the detected aggressor signal based on the detected property of the aggressor signal, and tune, based on the identified aggressor signal pattern, the tunable RF front end to suppress an interference of the aggressor signal with the tunable RF front end.

[0062] With the solution as proposed herein, the property of an aggressor signal which drives the tunable RF front end into compression can be detected by an observation receive system, and an aggressor signal pattern of the detected aggressor signal may be identified by the correlator based on the detected property of the aggressor signal, and then the tunable RF front end may be tuned based on the identified aggressor signal pattern to suppress an interference of the aggressor signal with the tunable RF front end. In this way, interference may be mitigated based on the identified aggressor. Therefore, power consumption may be improved since handover and retransmission of data due to the interference may be avoided.Example Circuits

[0063] Reference is now made to Fig. 2, which illustrates an example circuit 200 for RF front end tuning according to some embodiments of the present disclosure. The example circuit 200 may be implemented in a UE, for example, the terminal device 120 as illustrated in Fig. 1 A.

[0064] The example circuit 200 may comprise a tunable RF front end 100, an observation receive system 117, and a correlator 114. The observation receive system 117 may be configured to detect a property (e.g. phase and / or envelope) of an aggressor signal which drives the tunable RF front end 100 into compression. As the power of a victim signal may be lower than the power of the aggressor signal, the observation receive system 117 may receive non-linear portion of a mixed signal of the aggressor signal, from which a property of the aggressor signal may be further detected. A hardware implementation of the observation receive system 117 may consume relatively low power since an ADC as well as complete demodulation and decoding is not needed.

[0065] The correlator 114 may be configured to identify an aggressor signal pattern of the detected aggressor signal based on the detected property of the aggressor signal, and tune, based on the identified aggressor signal pattern, the tunable RF front end 100 to suppress an interference of the aggressor signal with the tunable RF front end 100.

[0066] In some embodiments, the tunable RF front end 100 may also be referred to as a configurable or adaptable RF front end 100. Tunable components of the tunable RF front end 100 may be one or more of: antennas & RF filters matching circuitry, “selectable filter bank”, or tunable bias settings used to adjust linearity of an active circuitry. Tunable settings of the tunable RF front end 100 could be one or more of: any analogue RF interference tuning or selection, antenna tuning, null steering in an antenna radiation pattern, simple antenna direction or directivity steering, front to back ratio tuning or switching to different antenna panels, and / or bias settings of amplifiers (e.g., LNA).

[0067] In some embodiments, the correlator 114 may be configured to identify the aggressor signal pattern based on at least one pre-determined aggressor signal pattern. For example, the correlator 114 may correlate an output of the observation receive system 117 with an aggressor signal pattern, and if a result of the correlation is larger than a pre-determined detection threshold level, the received signal may be identified as a signal type associated with the aggressor signal pattern associated with pre-determined detection threshold level. In some embodiments, the correlator 114 may be configured to identify the aggressor signal pattern based on a learning algorithm based on machine learning or artificial intelligence. The learning algorithm may be used to learn and identify interfering signals and RF systems and thereby control and tune the tunable RF front end 100 and optimize quality of service.

[0068] In some embodiments, the correlator 114 may tune the tunable RF front end 100 by configuring tunable components of the tunable RF front end 100 as described herein, for example, changing a filter bank selection that is suitable for the identified aggressor signal pattern, etc. In this way, adjacent channel power from a transmitter may be reduced due to improved filter performance.

[0069] In some embodiments, the UE apparatus may further comprise a baseband control system 115, wherein the at least one of the pre-determined aggressor signal patterns or the learning algorithm may be programed or re-programed by the baseband control system 115. In other words, the correlator 114 may potentially be programmed “on the fly” by the baseband control system 115. In some embodiments, the correlator 114 may be programmed by the baseband control system 115 via any type of signal, serial bit stream, 3 wire I2C busses. In some embodiments, the baseband control system 115 may comprise at least one micro controller. As aggressor signal patterns may be programmed beforehand into the correlator 114, the correlator 114 may tune, before a real problem arises, the tunable RF front end 100 to mitigate the problem. Because of the fast configuration of the RF Front end 100 when interference is detected, Qualityof Service may be improved since simultaneous use of multiple systems or radio access technologies (RATs) is enabled.

[0070] In some embodiments, the pre-determined aggressor signal patterns (also referred to as aggressor IDs) may be programmed into memory during production or configured for end user depending on location region and operator. For example, in case the operator that the SIM is locked to is not using band 7, 39, 40 & 41, there should not be any coexistence problems with the 2.4 GHz ISM band. In case of travel to another country or region and roaming to a network that do use the spectrum adjacent to ISM bands the algorithm should be changed accordingly. In addition, aggressor signal patterns may automatically be updated and learnt during use of the UE based on information captured during nonlinear reception and RF settings as described above.

[0071] Here are some examples of synchronization patterns and bands that can be configured during production or when a UE is configured for use for specific operators:Example 1: Bluetooth:

[0072] 4 bits Preamble pattern followed by 64 bits SYNC word and 4 bits trailer. UE should know its own Bluetooth SYNC word and the timing between preamble and trailer is also unique, so that detection of Bluetooth interference may be possible.Example 2: Digital enhanced cordless telecommunications (DECT)

[0073] DECT uses unique synchronization patterns that are the same for all RFPs (Radio Fixed Part) and differs from handsets that a different unique synchronization pattern, but exact same one is used for all handsets.

[0074] Source of DECT interference can in this way be uniquely identified as being handset or RFP’s. DECT is standardized for 2.4 GHz ISM band as well as for a band originally specified for DECT: 1880 MHz to 1900 MHz (EU).Example 3: Wi-Fi

[0075] For Wi-Fi 802.11 OFDM systems, short preamble, long preamble, signal field are all part of the first information in a Wi-Fi frame, they are not scrambled and are all BPSK modulated, which in turn means that the phase detector 106 is sufficient to demodulate such signal.

[0076] Since the Wi-Fi Signal field contains information about: data rate, length of the physical service data unit (PSDU) (actual payload) an exact length of the Wi-Fi frame may be detected once the signal field has been decoded.Example 4: 3GPP Systems

[0077] Reference signals like primary synchronization signals (PSS) as used for 5G in the downlink direction make use of binary phase shift keying (BPSK) modulation which is detectable using a phase / frequency detector followed by hardware-based correlator 114. Reference signals, SRS as used for uplink in 3 GPP systems make use of modulation schemes that can also be detected by use of phase / frequency detector.

[0078] It is to be noted that the embodiments of the present disclosure may be used to mitigate coexistence of any combination of systems, and aggressor / victim can be swapped between the examples listed above and are not limited to the listed examples.

[0079] In some embodiments, as illustrated in Fig. 3, the aggressor signal may be sensed via a coupler 102, wherein the coupler 102 is connected to or within the tunable RF front end 100, a forward coupling path of the coupler 102 is connected with observation receive system 117, a noncoupled transmission path of the coupler 102 is connected with the baseband control system 115. In some embodiments, the coupler 102 may be located inside the tunable RF front end 100 or directly at an antenna port. Coupling loss of 20 to 30 dB can be tolerable since low noise figure is not critical for the observation receive system 117 connected to the forward coupling path of the coupler 102.

[0080] It is to be understood that a UE noise figure as agreed in 3GPP is 10 dB. Assuming 25 dB loss in the coupler 102, this would result in noise levels illustrated on Table 1. A noise bandwidth for a B41 RF front end 100 filter is approximately 220 MHz since bandwidth for B41 is 196 MHz and practical filter would have roll off due to temperature drift and finite Q value of the used resonators. Thermal noise level (kTB noise) in 220 MHz bandwidth can be calculated to -55 dBm and for a 20 MHz bandwidth the noise level is -66 dBm assuming a noise temperature of 300 K. 300 K is commonly used for terrestrial radio communications when calculating link budgets. As stated above the receive system which is designed to comply with 3GPP requirements would run into linearity problems when the in-band blocking signals (or test signals for intermodulation) are above about -46 dBm. It is therefore possible to receive such interfering signals without any problems since the interfering signal is at least 9 dB above the noise floor at the input of the observation receive system 117.Table 1Noise bandwidth vs frequency / FE NFFE NF =0 FE NF, dB FE NF, dBBW [Hz] ktb [dBm / Hz] 35 101.00E+00 -174 -139 -1641.41E+06 -112 -77 -1025.00E+06 -107 -72 -971.00E+07 -104 -69 -942.00E+07 -101 -66 -914.00E+07 -98 -63 -888.00E+07 -95 -60 -851.60E+08 -92 -57 -822.20E+08 -90 -55 -804.00E+08 -88 -53-788.00E+08 -85 -50 -751.00E+09 -84 -49 -74

[0081] As only strong RF signals that are well above the noise floor and strong enough to drive LNA’s and ADC’s into compression need to be fed into the non-linear receive paths such high coupling loss (20 to 30 dB) can possibly be considered since only RF signals stronger than about -50 dBm need to be decoded in the nonlinear receive circuitry described below. The coupling loss of coupler 102 is for this reason not a problem and even for some embodiments there might be LNA’s integrated in the RF Front end 100 whereby the coupling loss of the coupler 102 is not a problem at all.

[0082] In some embodiments, the coupler 102 may reuse a coupler 102 for other purpose, for example, transmit envelope tracking, predistortion and other transmit closed loop tuning or control means. In this way, there is no need for additional coupler 102.

[0083] In some embodiments, the UE apparatus may further comprise a feedback receiver with an output terminal connected to the baseband control system 115. The forward coupling path of the coupler 102 may be connected to an input terminal of the observation receive system 117 and an input terminal of the feedback receiver via a power splitter.

[0084] Reference is now made to Fig. 3, which illustrates an example circuit 300 for RF front end tuning according to some embodiments of the present disclosure. The example circuit 300 may be implemented in a UE, for example, the terminal device 120 as illustrated in Fig. 1 A. The example circuit 300 may be based on the example circuit 200.

[0085] In some embodiments, the observation receive system 117 may comprise a phase detector 106 configured to detect a phase of the aggressor signal and an envelope detector 105 for detecting an envelope of the aggressor signal. In some embodiments, the phase detector 106 and the envelope detector 105 may be connected to the coupler 102 via a power splitter 104.

[0086] In frequency modulation (FM) receivers (such as FM radio, nordic mobile telephone (NMT), global system for mobile communications (GSM)), the signal is on purpose driven into compression (limiter amplifier) before being fed into a discriminator detector which provide an output signal which is proportional to the phase or frequency of the input signal.

[0087] In some embodiments, the phase detector 106 may comprise a 90-degree phase shifter and a s-curve detector. With a FM signal input to the phase detector 106, the phase of the FM signal may be detected by the following steps:1. FM Signal Representation: The FM signal can be represented as:( fta>ct + Aa> I m(r)dT'owhere:o A is the amplitude of the carrier signal.o o)cis the carrier angular frequency.o Am is the frequency deviation.o m(t) is the modulating signal.2. Phase Shifting: The FM signal is split into two paths. One path is phase-shifted by 90 degrees: ( fta>ct + Aw I m(r)dT'o3. Mixing: The original signal, s(t), and the phase-shifted signal, s90(t), are mixed using a multiplier:Fmi W = s(t) - S90(0Substituting the expressions for s(t) and s90(t):( ft \ / ft 'a>ct + Aw I m(r)dT I - A sin I a)ct + Aw I m(r)dTIo / \ Io4. Trigonometric Identity: Rewriting using trigonometric identity:A2( ( rfFmix(t)=“5“ sin I 2 I a)ct + Aw I m(r)dT2 \ \ Io5. Low-pass filtering: The mixed signal is passed through a low-pass filter to remove high-frequency components, leaving the baseband signal:FLPF(t) « Aw • m(t)6. S-curve detector: The s-curve detector produces an output voltage Vout(t) that is proportional to the frequency deviation:>ut( = k - f - m t)where k is a constant of proportionality.

[0088] The 90-degree phase shifter and s-curve detector work together to convert the frequency variations of the FM signal into amplitude variations. The phase shifter creates a quadrature signal, the mixer combines the original and phase-shifted signals, and the low-pass filter extracts the baseband signal. The s-curve detector then produces an output proportional to the frequency deviation, recovering the original modulating signal m(t).

[0089] For example, a sounding reference signal (SRS) in 3GPP 5G NR uplink is transmitted by UE to provide gNB with information about an uplink channel. Here we utilize the SRS for detection of an interfering 3 GPP signal by correlating Vout(t) from the S-curve detector with a known SRS sequence. If the output of the correlator 114 is larger than a pre-determined detection threshold level a control signal is sent to the filter bank (of the tunable RF front end 100) to indicate 3GPP interference presence. A filter bank selection may be changed according to the control signal.

[0090] In some embodiments, the envelope detector 105 may provide an output signal that is proportional to envelope or amplitude of an input signal. It can be implemented as a rectifier or diode detector or any other implementation that provide a base band signal that is proportional to the RF power of the input signal.

[0091] In some embodiments, the observation receive system 117 may further comprise a limiter amplifier 103 connected serially with the phase detector 106. Regardless of any input signal amplified to same amplitude at an output of the limiter amplifier 103, phase information of the signal may be maintained in this way. The limiter amplifier 103 is used to provide a signal strong enough to drive the phase detector 106 in a stable way. Even white noise is amplified and fed into the phase detector 106 with same power level, the phase detection can still work as for the strong deterministic RF signals.

[0092] In some embodiments, the observation receive system 117 may further comprise a tunable low pass filter 116 connected serially with the phase detector 106. The tunable low pass filter 116 may adapt a noise bandwidth to a bandwidth of an interfering RF signal that cause nonlinear problems. In this manner the sensitivity may be adapted at any time according to the conditions.

[0093] In some embodiments, the observation receive system 117 may further comprise a low pass filter 107 connected serially with the envelope detector 105. The low pass filter 107 may limit a bandwidth of an output from the envelope detector 105.

[0094] In some embodiments, the UE apparatus may further comprise a first selective switch 111with two terminals connected to an output of the phase detector 106 and the non-coupled transmission path of the coupler 102 respectively and one terminal connected to a first input terminal of the baseband control system 115.

[0095] In some embodiments, the first selective switch 111 is controlled by a control signal Ctr4, and wherein the control signal Ctr4 is dependent on an output of the envelope detector 105.

[0096] In some embodiments, the baseband control system 115 may comprise an analog-to-digital converter (ADC) or a RF transceiver 112 connected to the first input terminal of the baseband control system 115, wherein the ADC is controlled by the control signal Ctr4. If the first selective switch 111 is set to connect with the output of the phase detector 106, a setpoint or dynamic range of the ADC may be set automatically and autonomously, as when nonlinear reception is enabled hardware is designed such that signal amplitude at the output of the phase detector 106 is constant.

[0097] In some embodiments, the value of the control signal Ctr4 is determined based on whether the output of the envelope detector 105 is above a predetermined threshold Thrl provided by the baseband control system 115. In some embodiments, the threshold may be programmed by the baseband control system 115 and changed dynamically depending on nature of interference, used frequency band and / or other parameters. The value of the control signal may be determined to be logical 0 or logical 1, wherein determination is implemented by a comparator 108. For example, if the output of the envelope detector 105 is above the predetermined threshold, the value of the control signal may be logical 1, otherwise value of the control signal may be logical 0.

[0098] In some embodiments, the value of the control signal Ctr4 is further dependent on at least one of control signals Ctrl and Ctr2 from the baseband control system 115, used to disable or enable the automatic control of the first selective switch 111 as the control signal Ctr4 can be forced to logical 1 regardless of the output from the comparator 108. In case Ctrl=l (true) and Ctr2=l (true) is the result that Ctr4=l (true) and a path of the phase detector 106 is selected as the first selective switch 111 is connected to an output of the tunable low pass filter 116. And the output from comparator 108 is ignored. This feature enables the system to function in cases where the desired signal is strong enough to trig the comparator 108 while maintaining very good signal quality, high SINR.

[0099] In case Ctrl=l (true) and Ctr2=0 (false) is control of the first selective switch 111 done from the output of the comparator 108 since “1” (true) at the output from the comparator 108 will propagate to the first selective switch 111 through the OR gate 109 and the AND gate 110.

[0100]

[0101] In some embodiments, an output terminal of the envelope detector 105 is further connected to a second input terminal of the baseband control system 115, and an output of the envelope detector 105 is used for a machine learning or artificial intelligence algorithm to identify the aggressor signal pattern. In some embodiments, the machine learning or artificial intelligence algorithm may also use the output of the phase detector 106 or other quality metrices to control and optimize the circuit as data is being collected during normal use and operation of the circuit. The second input terminal of the baseband control system 115 may connect to a second ADC or transceiver 113.

[0102] In some embodiments, a feedback receiver already implemented and used in current designs could be reused in TDD mode and the input to the power splitter 104 could be to the feedback receiver.

[0103] In some embodiments, the element described above may be implemented by digital or analog hardware. In some embodiments, latency requirements as well as power consumption and costs may determine where an optimum split between digital and analog implementation of the circuit should be.

[0104] In some embodiments, the power splitter 104, the envelope detector 105, the limiter amplifier 103, the low pass filter 107, the comparator 108, the OR gate 109, and / or the AND gate 110 may imply simple signal processing (digital or analog hardware) that should be fast and use low power since the bandwidth of the signals to be decoded is most likely relatively small.

[0105] Reference is now made to Fig. 4, which illustrates an example circuit 400 for RF front end tuning according to some embodiments of the present disclosure. The example circuit 300 may be implemented in a UE, for example, the terminal device 120 as illustrated in Fig. 1 A. The example circuit 400 may be based on the example circuit 200.

[0106] In some embodiments, the wide band linear receiver is selectively connected to the coupler 102 or a second front end via a second selective switch.

[0107] In some embodiments, the observation receive system 117 may comprise a wide band linear receiver 210. High linearity is obtained due to high coupling loss which increases IIP3 point of the wide band linear receiver 210 by same factor as a loss in the coupler 102 by maybe up to 35 dB.

[0108] In some embodiments, the observation receive system 117 may further comprise a tunable filter 213. The tunable filter 213 may reuse a filter normally used in front of the ADC or other baseband input circuitry and could be implemented as a band pass filter or low pass filterdepending on the exact RF architecture: Low IF, Zero IF or direct RF sampling of the RF carrier frequency. Part of the receive selectivity is normally implemented in this filter, which in turn means that it must be adaptable to the various bandwidths that the system needs to support. In addition, the filter needs to be tuned to a bandwidth that is large enough to enable the features described above. In one example, it is likely that 400 MHz or 800 MHz bandwidth can be supported in case the ADC and base band used for the auxiliary linear receiver are intended for FR2 bands, as in a millimeter wave (MM wave) FE Module. In such case the entire spectrum covering 3 GPP frequency bands B7, B38, B40, and B41 as well as the 2.4 GHz ISM band can be monitored. The wanted signal, W, may not be detectable by the baseband. “UW” refer to the unwanted strong signals that cause the strong IMD3 product. For the wide band linear receiver 210, the IMD3 product may not be detectable and only the two unwanted signals may be detectable due to the high noise figure introduced with high coupling loss (30 dB in this example). Two tone intermodulation and IIP3 is usually considered, however any number of tones can potentially cause similar problems, like: One tone (IMD1), IMD3... IMDn. It is expected for practical systems that the 4th or 5th order may be the highest order of intermodulation products that can cause problems.Example Method

[0109] Fig. 5 shows a flowchart of an example method 500 implemented at a UE apparatus in accordance with some embodiments of the present disclosure. The UE apparatus comprises a tunable RF front end 100, an observation receive system 117, and a correlator 114.

[0110] At block 510, the observation receive system 117 detects a property of an aggressor signal interfering with the tunable RF front end 100.

[0111] At block 520, the correlator 114 identifies an aggressor signal pattern of the detected aggressor signal based on the detected property of the aggressor signal.

[0112] At block 530, the correlator 114 tunes, based on the identified aggressor signal pattern, the tunable RF front end 100 to suppress an interference of the aggressor signal with the tunable RF front end 100.

[0113] In some embodiments, the observation receive system comprises a phase detector configured to detect a phase of the aggressor signal and an envelope detector for an envelope of the aggressor signal.

[0114] In some embodiments, the observation receive system comprises a wide band linear receiver.

[0115] In some embodiments, the correlator is configured to identify the aggressor signal pattern based on at least one of at least one pre-determined aggressor signal pattern; a learning algorithm based on machine learning or artificial intelligence.

[0116] In some embodiments, the UE apparatus further comprises a baseband control system and wherein the at least one of the pre-determined aggressor signal patterns or the learning algorithm is programed or re-programed by the baseband control system.

[0117] In some embodiments, the aggressor signal is sensed via a coupler, wherein the coupler is connected to or within the tunable RF front end, a forward coupling path of the coupler is connected with observation receive system, a non-coupled transmission path of the coupler is connected with the baseband control system.

[0118] In some embodiments, the UE apparatus further comprises a feedback receiver with an output terminal connected to the baseband control system, wherein the forward coupling path of the coupler is connected to an input terminal of the observation receive system and an input terminal of the feedback receiver via a power splitter.

[0119] In some embodiments, the UE apparatus further comprises a first selective switch with two terminals connected to an output of the phase detector and the non-coupled transmission path of the coupler respectively and one terminal connected to a first input terminal of the baseband control system.

[0120] In some embodiments, the first selective switch is controlled by a control signal, and wherein the control signal is dependent on an output of the envelope detector.

[0121] In some embodiments, the baseband control system comprises an analog-to-digital converter (ADC) or a RF transceiver connected to the first input terminal of the baseband control system, wherein the ADC is controlled by the control signal.

[0122] In some embodiments, the value of the control signal is determined based on whether the output of the envelope detector is above a predetermined threshold provided by the baseband control system.

[0123] In some embodiments, the value of the control signal is further dependent on at least one of an enable signal and a disable signal from the baseband control system, wherein the enable signal is able to set the control signal to logical 1 and the disable signal is able to set the control signal to logical 0.

[0124] In some embodiments, an output terminal of the envelope detector is further connected to a second input terminal of the baseband control system, and an output of the envelope detector isused for a machine learning or artificial intelligence algorithm to identify the aggressor signal pattern.

[0125] In some embodiments, the wide band linear receiver is selectively connected to the coupler or a second front end via a second selective switch.

[0126] Fig. 6 is a simplified block diagram of a device 600 that is suitable for implementing embodiments of the present disclosure. The device 600 may be provided to implement the communication device, for example the terminal device 120 or the network device 110 as shown in Fig. 1. As shown, the device 600 includes one or more processors 610, one or more memories 620 coupled to the processor 610, and one or more communication modules 640 coupled to the processor 610.

[0127] The communication module 640 is for bidirectional communications. The communication module 640 has at least one antenna to facilitate communication. The communication interface may represent any interface that is necessary for communication with other network elements.

[0128] The processor 610 may be of any type suitable to the local technical network and may include one or more of the following: general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs) and processors based on multicore processor architecture, as non-limiting examples. The device 600 may have multiple processors, such as an application specific integrated circuit chip that is slaved in time to a clock which synchronizes the main processor.

[0129] The memory 620 may include one or more non-volatile memories and one or more volatile memories. Examples of the non-volatile memories include, but are not limited to, a read only memory (ROM) 624, an electrically programmable read only memory (EPROM), a flash memory, a hard disk, a compact disc (CD), a digital video disk (DVD), and other magnetic storage and / or optical storage. Examples of the volatile memories include, but are not limited to, a random access memory (RAM) 622 and other volatile memories that will not last in the powerdown duration.

[0130] A computer program 630 includes computer executable instructions that are executed by the associated processor 610. The program 630 may be stored in the ROM 624. The processor 610 may perform any suitable actions and processing by loading the program 630 into the RAM 622.

[0131] The communication module 640 is for bidirectional communications. Thecommunication module 640 has at least one antenna to facilitate communication. The communication interface may represent any interface that is necessary for communication with other network elements.

[0132] The embodiments of the present disclosure may be implemented by means of the program 630 so that the device 600 may perform any process of the disclosure as discussed with reference to Figs. 2 to 5. The embodiments of the present disclosure may also be implemented by hardware or by a combination of software and hardware.

[0133] In some embodiments, the program 630 may be tangibly contained in a computer readable medium which may be included in the device 600 (such as in the memory 620) or other storage devices that are accessible by the device 600. The device 600 may load the program 630 from the computer readable medium to the RAM 622 for execution. The computer readable medium may include any types of tangible non-volatile storage, such as ROM, EPROM, a flash memory, a hard disk, CD, DVD, and the like. Fig. 7 shows an example of the computer readable medium 700 in form of CD or DVD. The computer readable medium has the program 630 stored thereon.

[0134] Generally, various embodiments of the present disclosure may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. Some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device. While various aspects of embodiments of the present disclosure are illustrated and described as block diagrams, flowcharts, or using some other pictorial representations, it is to be understood that the block, apparatus, system, technique or method described herein may be implemented in, as non-limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.

[0135] The present disclosure also provides at least one computer program product tangibly stored on a non-transitory computer readable storage medium. The computer program product includes computer-executable instructions, such as those included in program modules, being executed in a device on a target real or virtual processor, to carry out the method as described above with reference to Figs. 2-5. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, or the like that perform particular tasks or implement particular abstract data types. The functionality of the program modules may be combined or split between program modules as desired in various embodiments. Machineexecutable instructions for program modules may be executed within a local or distributed device. In a distributed device, program modules may be located in both local and remote storage media.

[0136] Program code for carrying out methods of the present disclosure may be written in any combination of one or more programming languages. These program codes may be provided to a processor or controller of a general purpose computer, special purpose computer, or other programmable data processing apparatus, such that the program codes, when executed by the processor or controller, cause the functions / operations specified in the flowcharts and / or block diagrams to be implemented. The program code may execute entirely on a machine, partly on the machine, as a stand-alone software package, partly on the machine and partly on a remote machine or entirely on the remote machine or server.

[0137] In the context of the present disclosure, the computer program codes or related data may be carried by any suitable carrier to enable the device, apparatus or processor to perform various processes and operations as described above. Examples of the carrier include a signal, computer readable medium, and the like.

[0138] The computer readable medium may be a computer readable signal medium or a computer readable storage medium. A computer readable medium may include but not limited to an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples of the computer readable storage medium would include an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. The term “non-transitory,” as used herein, is a limitation of the medium itself (i.e., tangible, not a signal) as opposed to a limitation on data storage persistency (e.g., RAM vs. ROM).

[0139] Further, while operations are depicted in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In certain circumstances, multitasking and parallel processing may be advantageous. Likewise, while several specific implementation details are contained in the above discussions, these should not be construed as limitations on the scope of the present disclosure, but rather as descriptions of features that may be specific to particular embodiments. Certain features that are described in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment may also be implemented in multiple embodiments separately or in any suitable sub-combination.

[0140] Although the present disclosure has been described in languages specific to structural features and / or methodological acts, it is to be understood that the present disclosure defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

Claims

WHAT IS CLAIMED IS:

1. A user equipment (UE) apparatus, comprising:a tunable radio frequency (RF) front end,an observation receive system configured to detect a property of an aggressor signal which drives the tunable RF front end into compression, anda correlator configured to identify an aggressor signal pattern of the detected aggressor signal based on the detected property of the aggressor signal, and tune, based on the identified aggressor signal pattern, the tunable RF front end to suppress an interference of the aggressor signal with the tunable RF front end.

2. The UE apparatus of claim 1, wherein the observation receive system comprises a phase detector configured to detect a phase of the aggressor signal and an envelope detector for detecting an envelope of the aggressor signal; orwherein the observation receive system comprises a wide band linear receiver.

3. The UE apparatus of claim 1, wherein the correlator is configured to identify the aggressor signal pattern based on at least one of:at least one pre-determined aggressor signal pattern; ora learning algorithm based on machine learning or artificial intelligence.

4. The UE apparatus of claim 2, wherein the UE apparatus further comprises a baseband control system and wherein the at least one of the pre-determined aggressor signal patterns or the learning algorithm is programed or re-programed by the baseband control system.

5. The UE apparatus of claim 4, wherein the aggressor signal is sensed via a coupler, wherein the coupler is connected to or within the tunable RF front end, a forward coupling path of the coupler is connected with observation receive system, a non-coupled transmission path of the coupler is connected with the baseband control system.

6. The UE apparatus of claim 5, wherein the UE apparatus further comprises a feedback receiver with an output terminal connected to the baseband control system, wherein the forward coupling path of the coupler is connected to an input terminal of the observation receive system and an input terminal of the feedback receiver via a power splitter.

7. The UE apparatus of claim 5, wherein the UE apparatus further comprises a first selective switch with two terminals connected to an output of the phase detector and the noncoupled transmission path of the coupler respectively and one terminal connected to a first input terminal of the baseband control system.

8. The UE apparatus of claim 7, wherein the first selective switch is controlled by a control signal, and wherein the control signal is dependent on an output of the envelope detector.

9. The UE apparatus of claim 8, wherein the baseband control system comprises an analog-to-digital converter (ADC) or a RF transceiver connected to the first input terminal of the baseband control system, wherein the ADC is controlled by the control signal.

10. The UE apparatus of claim 8 or 9, wherein the value of the control signal is determined based on whether the output of the envelope detector is above a predetermined threshold provided by the baseband control system.

11. The UE apparatus of claim 10, wherein the value of the control signal is further dependent on at least one of an enable signal and a disable signal from the baseband control system, wherein the enable signal is able to set the control signal to logical 1 and the disable signal is able to set the control signal to logical 0.

12. The UE apparatus of any of claims 6 to 11, wherein an output terminal of the envelope detector is further connected to a second input terminal of the baseband control system, and an output of the envelope detector is used for a machine learning or artificial intelligence algorithm to identify the aggressor signal pattern.

13. The UE apparatus of claim 2, wherein the wide band linear receiver is selectively connected to the coupler or a second front end via a second selective switch.

14. A method implemented at a user equipment (UE) apparatus, wherein the UE apparatus comprises a tunable radio frequency (RF) front end, an observation receive system, and a correlator, wherein the method comprises:detecting, by the observation receive system, a property of an aggressor signal which drives the tunable RF front end into compression;identifying, by the correlator, an aggressor signal pattern of the detected aggressor signal based on the detected property of the aggressor signal; andtuning, based on the identified aggressor signal pattern, the tunable RF front end to suppress an interference of the aggressor signal with the tunable RF front end.

15. A computer program comprising instructions which, when executed by an apparatus, cause the apparatus to perform the method of claim 14.

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