WO2025189481A1

WO2025189481A1 - Frequency shift associated with backscattering transmission

Info

Publication number: WO2025189481A1
Application number: PCT/CN2024/082055
Authority: WO
Inventors: Yonggang Wang; Yong Liu; Tao Tao; Yan Meng; Jianguo Liu
Original assignee: Nokia Shanghai Bell Co Ltd; Nokia Solutions and Networks Oy; Nokia Technologies Oy
Current assignee: Nokia Shanghai Bell Co Ltd; Nokia Solutions and Networks Oy; Nokia Technologies Oy
Priority date: 2024-03-15
Filing date: 2024-03-15
Publication date: 2025-09-18
Anticipated expiration: 2026-09-15

Abstract

Embodiments of the present disclosure relate to a frequency shift associated with a backscattering transmission. In one aspect, a first apparatus receives an indication of performing a frequency shift associated with a backscattering transmission of the first apparatus. Based on the indication, the first apparatus performs the frequency shift of an activation signal to a target subband. Based on the frequency shifted activation signal on the target subband, the first apparatus performs a backscattering transmission. In this way, the original activation signal may be isolated from the backscattering signal through frequency division multiplexing. Therefore, interference between the activation signal and the backscattering transmission can be minimized.

Description

FREQUENCY SHIFT ASSOCIATED WITH BACKSCATTERING TRANSMISSION

FIELD

Various example embodiments relate to the field of communication and in particular, to devices, methods, apparatuses and a computer readable storage medium for a frequency shift associated with a backscattering transmission.

BACKGROUND

With the development of communication technology, Internet of Things (IoT) has been introduced for ultra-low cost and ultra-low power devices. The IoT is a network of interrelated devices that connect and exchange data with other IoT devices and the cloud. IoT devices are typically embedded with technology such as sensors and software and can include mechanical and digital machines and consumer objects.

With IoT, accessing to information from anywhere at any time on any device is enabled, and large amounts of data may be collected from multiple devices. In addition, communications between connected electronic devices are improved. However, there are still some issues associated with the backscattering transmission to be addressed.

SUMMARY

In general, example embodiments of the present disclosure provide a solution for a frequency shift related to a backscattering transmission.

In a first aspect, there is provided a first apparatus. The first apparatus comprises at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the first apparatus at least to: receive an indication of performing a frequency shift associated with a backscattering transmission of the first apparatus, perform the frequency shift of an activation signal to a target subband based on the indication, and perform the backscattering transmission based on the frequency shifted activation signal on the target subband.

In a second aspect, there is provided a second apparatus. The second apparatus comprises at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the second apparatus at least to: receive an indication from a third apparatus for receiving a backscattering transmission of a first apparatus, and receive the backscattering transmission on the target subband from the first apparatus based on the indication. The indication indicates a target subband for a frequency shift associated with the backscattering transmission.

In a third aspect, there is provided a third apparatus. The third apparatus comprises at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the third apparatus at least to: determine a target subband for a frequency shift associated with a backscattering transmission of a first apparatus, and transmit an indication for receiving the backscattering transmission to a second apparatus. The indication indicates the target subband.

In a fourth aspect, there is provided a fourth apparatus. The fourth apparatus comprises at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the fourth apparatus at least to: store capability information of a first apparatus on a frequency shift distance associated with a backscattering transmission of the first apparatus, and transmit the capability information of the first apparatus to a third apparatus.

In a fifth aspect, there is provided a method. The first apparatus receives an indication of performing a frequency shift associated with a backscattering transmission of the first apparatus. Based on the indication, the first apparatus performs the frequency shift of an activation signal to a target subband. Based on the frequency shifted activation signal on the target subband, the first apparatus performs the backscattering transmission.

In a sixth aspect, there is provided a method. The second apparatus receives from a third apparatus an indication for receiving a backscattering transmission of a first apparatus, and the indication indicates a target subband for a frequency shift associated with the backscattering transmission. Based on the indication, the second apparatus receives the backscattering transmission on the target subband from the first apparatus.

In a seventh aspect, there is provided a method. The third apparatus determines a target subband for a frequency shift associated with a backscattering transmission of a first apparatus. The third apparatus then transmits an indication for receiving the backscattering transmission to a second apparatus. The indication indicates the target subband.

In an eighth aspect, there is provided a method. The fourth apparatus stores capability information of a first apparatus on a frequency shift distance associated with a backscattering transmission of the first apparatus. The fourth apparatus then transmits the capability information of the first apparatus to a third apparatus.

In a ninth aspect, there is provided a first apparatus. The first apparatus comprises means for receiving an indication of performing a frequency shift associated with a backscattering transmission of the first apparatus, means for performing the frequency shift of an activation signal to a target subband based on the indication; and means for performing the backscattering transmission based on the frequency shifted activation signal on the target subband.

In a tenth aspect, there is provided a second apparatus. The second apparatus comprises means for receiving an indication from a third apparatus for receiving a backscattering transmission of a first apparatus, and the indication indicates a target subband for a frequency shift associated with the backscattering transmission; and means for receiving the backscattering transmission on the target subband from the first apparatus based on the indication.

In an eleventh aspect, there is provided a third apparatus. The third apparatus comprises means for determining a target subband for a frequency shift associated with a backscattering transmission of a first apparatus, and means for transmitting an indication for receiving the backscattering transmission to a second apparatus, and the indication indicates the target subband.

In twelfth aspect, there is provided a fourth apparatus. The fourth apparatus comprises means for storing capability information of a first apparatus on a frequency shift distance associated with a backscattering transmission of the first apparatus, and means for transmitting the capability information of the first apparatus to a third apparatus.

In a thirteenth aspect, there is provided a non-transitory computer readable medium comprising program instructions for causing an apparatus to perform at least the method according to any one of the above fifth to eighth aspect.

In a fourteenth aspect, there is provided a computer program comprising instructions, which, when executed by an apparatus, cause the apparatus at least to: receive an indication of performing a frequency shift associated with a backscattering transmission of the first apparatus, perform the frequency shift of an activation signal to a target subband based on the indication; and perform the backscattering transmission based on the frequency shifted activation signal on the target subband.

In a fifteenth aspect, there is provided a computer program comprising instructions, which, when executed by an apparatus, cause the apparatus at least to: receive an indication from a third apparatus for receiving a backscattering transmission of a first apparatus, and receive the backscattering transmission on the target subband from the first apparatus based on the indication. The indication indicates a target subband for a frequency shift associated with the backscattering transmission.

In a sixteenth aspect, there is provided a computer program comprising instructions, which, when executed by an apparatus, cause the apparatus at least to: determine a target subband for a frequency shift associated with a backscattering transmission of a first apparatus, and transmit an indication for receiving the backscattering transmission to a second apparatus. The indication indicates the target subband.

In a seventeenth aspect, there is provided a computer program comprising instructions, which, when executed by an apparatus, cause the apparatus at least to: store capability information of a first apparatus on a frequency shift distance associated with a backscattering transmission of the first apparatus, and transmit the capability information of the first apparatus to a third apparatus.

In an eighteenth aspect, there is provided a first apparatus. The first apparatus comprises receiving circuitry configured to receive an indication of performing a frequency shift associated with a backscattering transmission of the first apparatus; first performing circuitry configured to perform the frequency shift of an activation signal to a target subband based on the indication; and second performing circuitry configured to perform the backscattering transmission based on the frequency shifted activation signal on the target subband.

In a nineteenth aspect, there is provided a second apparatus. The second apparatus comprises first receiving circuitry configured to receive an indication from a third apparatus for receiving a backscattering transmission of a first apparatus, and the indication indicates a target subband for a frequency shift associated with the backscattering transmission; and second receiving circuitry configured to receive the backscattering transmission on the target subband from the first apparatus based on the indication.

In a twentieth aspect, there is provided a third apparatus. The third apparatus comprises determining circuitry configured to determine a target subband for a frequency shift associated with a backscattering transmission of a first apparatus; and transmitting circuitry configured to transmit an indication for receiving the backscattering transmission to a second apparatus, and the indication indicates the target subband.

In a twenty-first aspect, there is provided a fourth apparatus. The fourth apparatus comprises storing circuitry configured to store capability information of a first apparatus on a frequency shift distance associated with a backscattering transmission of the first apparatus; and transmitting circuitry configured to transmit the capability information of the first apparatus to a third apparatus.

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 example embodiments of the present disclosure will become easily comprehensible through the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

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

Fig. 1A illustrates an example network environment in which example embodiments of the present disclosure may be implemented;

Fig. 1B illustrates a first example of topology associated with aspects of the present disclosure;

Fig. 1C illustrates a second example of topology associated with aspects of the present disclosure;

Fig. 1D illustrates a third example of topology associated with aspects of the present disclosure;

Fig. 1E illustrates example bi-static scenarios associated with aspects of the present disclosure;

Fig. 2 illustrates an example signaling chart illustrating an example process according to some embodiments of the present disclosure;

Fig. 3 illustrates an example of frequency shift according to some embodiments of the present disclosure;

Fig. 4 illustrates an example of transmitter structure of filtered based orthogonal frequency division multiplexing (OFDM) according to some embodiments of the present disclosure;

Fig. 5 illustrates a simulation of the interference suppression of universal filtered OFDM (UF-OFDM) according to some embodiments of the present disclosure;

Fig. 6 illustrates an example procedure of proposed solution according to some embodiments of the present disclosure;

Fig. 7 illustrates another example procedure of proposed solution according to some embodiments of the present disclosure;

Fig. 8 illustrates a flowchart of a method implemented at a first apparatus according to some embodiments of the present disclosure;

Fig. 9 illustrates a flowchart of a method implemented at a second apparatus according to some embodiments of the present disclosure;

Fig. 10 illustrates a flowchart of a method implemented at a third apparatus according to some embodiments of the present disclosure;

Fig. 11 illustrates a flowchart of a method implemented at a fourth apparatus according to some embodiments of the present disclosure;

Fig. 12 illustrates a simplified block diagram of an apparatus that is suitable for implementing embodiments of the present disclosure; and

Fig. 13 illustrates a block diagram of an example computer readable medium in accordance with some embodiments of the present disclosure.

Throughout the drawings, the same or similar reference numerals represent the same or similar element.

DETAILED DESCRIPTION

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 example embodiments of the present disclosure, without suggesting any limitation as to the scope of the disclosure. The example embodiments of the present disclosure described herein can be implemented in various manners other than the ones described below.

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.

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, or characteristic 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.

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.

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: <a list of two or more elements>” and “at least one of <a list of two or more elements>” 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.

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 not be present when it is not needed for operation.

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.

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 example embodiments of the present disclosure may be embodied. It should not be seen as limiting the scope of the present disclosure to only the aforementioned system.

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 new radio (NR) NB (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.

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 personal digital assistant (PDA) , portable computers, desktop computer, image capture terminal devices such as digital cameras, gaming terminal devices, music storage and playback appliances, vehicle-mounted 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.

The term “A-IoT device” refers to a Ambient IoT device without batteries or with limited energy storage capabilities. For A-IoT device, energy is provided by harvesting radio waves, light, motion, heat, or any other suitable source. A-IoT device can also be called zero-power terminals, near-zero power terminals, passive IoT device, ambient backscatter communication (AmBC) device, tag, etc. Compared with low-power and wide-coverage services, such as narrow band (NB) IoT, enhance machine type communication (eMTC) , A-IoT has lower complexity and lower power consumption, and is suitable for more application scenarios.

A-IoT in 3GPP may enable ultra-low cost and ultra-low power A-IoT devices. The density of the A-IoT device deployment can be expected to be many orders of magnitudes higher compared to any known 3GPP deployment. Thus, a key element for such deployment is the localization of A-IoT devices. It is not only required to know the identity of the A-IoT device and to communicate with the device, but equally important is knowledge of the position of the A-IoT device.

Fig. 1A illustrates an example network environment 100A in which example embodiments of the present disclosure may be implemented. The environment 100A, which may be a part of a communication network, comprises terminal devices, network devices. As illustrated in Fig. 1A, the network environment 100A may comprise a first apparatus 110, a second apparatus 120, a third apparatus 130, and a fourth apparatus 140. The first apparatus 110 may be a device with the capability of backscattering transmission and frequency shift, such as an A-IoT device. The second apparatus 120 may be a terminal device. The third apparatus 130 may be a base station. The fourth apparatus 140 may be a core network node. The first apparatus 110, the second apparatus 120 and the third apparatus 130 may communicate with each other.

It is to be understood that the number of devices is only for the purpose of illustration without suggesting any limitations. The system 100A may include any suitable number of devices adapted for implementing embodiments of the present disclosure. Although not shown, it would be appreciated that one or more terminal devices or second network devices may be located in the environment 100A.

Communications in the communication system 100A 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.

A-IoT study relies on ultra-low complexity devices with ultra-low power consumption for the very-low end IoT applications. Three different device types are defined below based on whether there is energy storage or not, and whether there is backscattering transmissions or active radio frequency (RF) transmissions. The first device type may be Device A, for which there are no energy storage, no independent signal generation or amplification, i.e., the device A can perform backscattering transmission. The second device type may be Device B, for which there is no independent signal generation but energy storage, i.e., the device B can perform backscattering transmission. The stored energy may be use for an amplification for reflected signals. The third device type may be Device C, for which there are energy storage, independent signal generation, i.e., the device C have active radio frequency (RF) components for transmission.

The topologies for A-IoT networks and devices are defined for the purposes of the study. In all these topologies, the A-IoT device may be provided with a carrier wave from other node (s) either inside or outside the topology. The links in each topology may be bidirectional or unidirectional. The BS, UE, assisting node, or intermediate node could be multiple BSs or UEs, respectively.

Fig. 1B illustrates a first example of topology associated with aspects of the present disclosure. As shown in Fig. 1B, the ambient IoT device 131 communicates bi-directionally with an intermediate node 132 between the ambient IoT device 131 and the BS 133. In the first example of topology, the intermediate node 132 can be a relay, IAB node, UE, repeater, etc. which is capable of an ambient IoT. The intermediate node 131 transfers ambient IoT data and/or signaling between the BS 133 and the ambient IoT device 131.

Fig. 1C illustrates a second example of topology associated with aspects of the present disclosure. As shown in Fig. 1C, the ambient IoT device 141 receives data and/or signalling from the assisting node 142 and transmits data and/or signalling to the BS 143.

Fig. 1D illustrates a third example of topology associated with aspects of the present disclosure. The ambient IoT device 141 receives data and/or signalling from the BS 143 and transmits data/signalling to the assisting node 142. In the second and third topology, the assisting node 142 can be a relay node, a IAB node, a UE, a repeater, etc., which is capable of ambient IoT.

There are monostatic and bi-static scenarios for the backscattering transmission. In other words, the backscattering transmission may comprise monostatic backscattering and/or bi-static backscattering. For the monostatic scenario, there may be a configuration consists of two components, i.e., an activator and a backscatter device, e.g., a tag. The activator as the carrier emitter first releases RF signals to activate the backscatter device. Once activated, the backscatter device performs modulation utilizing the same RF signals from an interrogator. The reflected modulated backscatter signals are then captured by the activator which also acts as the reader. Since the carrier emitter and the backscatter reader are co-located, the backscattered signal suffers from a round-trip path loss. The monostatic configuration is mostly adopted for short-range radio frequency identification (RFID) applications.

For the bi-static backscattering, compared to the monostatic counterpart, the single activator is replaced by a separate carrier emitter and a separate reader. The configuration of bi-static backscattering allows setting up more flexible network topologies. For example, a carrier emitter can be placed at an optimal location for backscatter device and readers. Fig. 1E illustrates example bi-static scenarios associated with aspects of the present disclosure. as shown in Fig. 1E, the base station 151 and 154 may be a carrier emitter, the base station 153 and the UE 156 may be a reader, and the device 152 and 155 may be a backscatter device.

Bi-static scenario introduces flexibility to device-reader distance by allowing the adjusting of activator location and can provide longer device-reader distance (e.g., the distance between device 152 and base station 153 or the distance between device 155 and UE 156) . The activator-device distance is limited by received power at device, which should be adequate to wake up the device and decode command message. On the other hand, the device-reader distance is not constrained by this requirement. The activator-device distance and device-reader distance depend on each other. The main advantage of the bi-static scenario is that it provides longer range compared to monostatic so as to allow operation in commercial cellular deployments.

For the first example of Topology shown in Fig. 1B, the communication between the intermedia node 132 and ambient IoT device 131 is the typical monostatic scenario, and the activator is the intermedia node 132. The second and third Topology shown in Fig. 1C or Fig. 1D are the typical bi-static scenario and the ambient IoT data is activated by the BS 143 or the assisting node 142, and the backscattering signal is received by another node among the BS 143 and the assisting node 142.

Frequency shift is a popular technique in the wireless communication, such as frequency shift keying (FSK) and frequency shift modulation (FSM) and so on. The frequency shifting has been introduced into the A-IoT to solve to the interference problem of incident signals on reflected signals.

It has been proposed that device B can include low power oscillator (e.g., resistance &capacitance, RC, ring oscillator) to implement backscatter frequency shifting and timekeeping for time shifting. Frequency shift is beneficial at the reader since the downlink (DL) and uplink (UL) can be frequency separated to match FDD duplex distance or reduce activator direct path interference, then the dynamic range can be maximized.

It also proposed that a key aspect is to solve the carrier-wave interference to the uplink receiver by applying e.g. FDD frequency shifter for backscatter modulation or RF local oscillator for internal carrier-wave generation. Correspondingly, A-IoT device with a few 100 μW peak power consumption is expected to include one or more of the following additional basic blocks: a power amplifier in analog demodulator; a power amplifier in analog modulator; a FDD frequency shifter, optionally in backscatter modulator; a RF local oscillator and mixer, only for heterodyne transmitter or receiver. In addition, whether an A-IoT device has the frequency shifting capability should also be considered.

As backscattering IoT devices co-exist with other devices in 3GPP networks, the A-IoT and 5G NR share the 5G time-frequency resources., if an A-IoT device is far from the gNB, the distance may be much larger than the maximum working range (e.g., 10m) in RFID, the A-IoT device still can be activated by a base station, i.e., the gNB using the topology depicted in Fig. 1E which requires downlink transmission by the base station such that bi-static scenario will share the downlink resources with limited capacity.

To coexist with 3GPP technologies, the activation signal could be the OFDM signal transmitted from a gNB or a UE. The activation signal will naturally generate interference at the receiver node. For example, interference at the receiver node may be generated when the assisting UE in the serving cell is receiving the backscatter signal, or another gNB in the other cell is receiving the backscatter signal due to the spatial propagation of wireless activator signal directly to the assisting UE.

In an interference cancellation method, the data in activation signal is detected, the generated identical interference is subtracted from the total received signal in reader. If an OFMD signal has been used for modulating the original data, it is complex to eliminate such interference from the activator to the reader, e.g., gNB to UE, since the data is agnostic.

According to some embodiments of the present disclosure, a solution is provided for the frequency shift related to the backscattering transmission. In one aspect of this solution, a first apparatus receives an indication of performing a frequency shift associated with a backscattering transmission of the first apparatus. Based on the indication, the first apparatus performs the frequency shift of an activation signal to a target subband. Based on the frequency shifted activation signal on the target subband, the first apparatus performs a backscattering transmission. In this way, the original activation signal may be isolated from the backscattering signal through frequency division multiplexing. Therefore, interference between the activation signal and the backscattering transmission can be minimized. Principles and implementations of embodiments of the present disclosure will be described in detail below with reference to Figs. 2-13.

Fig. 2 illustrates a signaling chart illustrating an example process 200 according to some embodiments of the present disclosure. For the purpose of discussion, the process 200 will be described with reference to Fig. 1A. The process 200 may involve the first apparatus 110, the second apparatus 120, the third apparatus 130, and the fourth apparatus 140. It would be appreciated that although the process 200 has been described in the communication environment 100A of Fig. 1A, this process may be likewise applied to other communication scenarios with similar issues.

In the process 200, the fourth apparatus 140 stores 201 capability information of the first apparatus 110 on a frequency shift distance. The frequency shift distance is associated with a backscattering transmission of the first apparatus 110. In some embodiments, the fourth apparatus may comprise a core network (CN) node. In some embodiments, the first apparatus 110 may comprise an A-IoT device. A-IoT devices have the capability to process the signals at specific frequencies, so as to frequency shift the activation signal and backscatter.

Additionally, the capability information may be stored during a registration procedure for the first apparatus 110. In an example, the frequency shift distance may be informed to network and stored in a CN node (e.g., network exposure function, NEF) when the A-IoT device is registered in the network. In some embodiments, the first apparatus 110 may transmit the capability information to the fourth apparatus 140, so that the fourth apparatus 140 can store the capability information of the first apparatus 110. For instance, the capability information on a frequency shift distance may be transmitted during a registration procedure for the first apparatus 110.

Continuing with reference to Fig. 2, the fourth apparatus 140 transmits 202 the capability information 203 to the third apparatus 130. In some embodiments, the third apparatus 130 may comprise a base station (e.g., a gNB) . In addition, the capability information 203 may be transmitted in a service request for the first apparatus 110, and the frequency shift distance may be a parameter of the service request. For example, when a service for A-IoT is initiated, as one parameter of the service request, the frequency shift distance may be carried in a signaling of the service request and sent to a gNB, i.e., the third apparatus 130. Correspondingly, the third apparatus 130 may receive 204 the capability information 203 from the fourth apparatus 140. As an example, the capability information may be received in a service request for the first apparatus 110, and the frequency shift distance may be a parameter of the service request. Additionally, the capability information may be stored in the third apparatus 130 when the second apparatus 120 is in inactive state. The capability information may be used in the next time if an activator/reader UE (i.e., the second apparatus 120) does not enter the idle state and wake again.

The third apparatus 130 determines 205 a target subband for a frequency shift associated with a backscattering transmission of the first apparatus 110. In some embodiments, the target subband may comprise a guard band, a reserved in-band, or the guard band and the reserved in-band. In some embodiments, the frequency shift may comprise a single sideband conversion. However, in other embodiments, the frequency shift may also be any other frequency conversion that is suitable for performing the frequency shift associated with the backscattering transmission. An illustrative example of the frequency shift is described with reference to Fig. 3.

Fig. 3 illustrates an example of frequency shift according to some embodiments of the present disclosure. As shown in Fig. 3, the backscattering signal is the frequency shifted activation signal and on the guard band. The guard band is embedded in the OFDM tones.

In some cases, backscattering communication overload makes guard band unable to accommodate the whole reflected signal. For example, performance deteriorates sharply due to the reflected signal conflicts. Some in-band tones of OFDM may be reserved for backscattering transmission. Such reserved in-band tones could be considered as the target band, and may be considered as nominal “guard-band” . The gNB may determine the appropriate OFDM subband as the activation signal to illuminate the A-IoT device based on the frequency shift distance. The A-IoT device frequency shifts the activation signal to the aforementioned reserved in-band tones of OFDM and additionally applies the OOK/ASK modulation. For example, this can be referred to as “frequency shift (FS) + OOK/ASK” .

Additionally, the target subband may be determined based on the capability information of the first apparatus 110 on a frequency shift distance associated with the backscattering transmission.

In some embodiments, the frequency shift distance may be fixed and limited number. For instance, the capability of the frequency shift distance may be fixed during manufacture for cost consideration and stored in the A-IoT device for a fixed characteristic. If the A-IoT devices has several different capabilities of the frequency shift distance, it shall support that the network to configure the actual frequency shift distance on demand for device.

In some embodiments, based on the capability information, the third apparatus 130 may further determine a source subband of an activation signal for the first apparatus 110. In an example, based on the parameter of frequency shift distance, the gNB determines the source subband for activation and the target subband for backscattering.

In this case of the A-IoT backscattering transmission co-existing with 3GPP systems, the A-IoT device is activated by signal which is one subband of OFDM signal. The gNB may determine which subband is used as the activation signal. In additional, the gNB may also determine which subband is the target subband the frequency shifts to, for example guard band or in-band tones reserved to the A-IoT device.

Reference is made back to Fig. 2, the third apparatus 130 transmits 210 an indication 215 for receiving the backscattering transmission to the second apparatus 120, and the indication 215 indicates the target subband. For instance, the gNB sends a backscatter receiving indication to a selected reader UE. As an example, the scheduling information to the selected reader UE is applied. On the other side of the communication, the second apparatus 120 receives 220 the indication 215 from the third apparatus 130. In addition, the second apparatus 120 may comprise a user equipment.

In some embodiments, the indication 215 may comprise first scheduling information for the second apparatus 120 receiving the backscattering transmission. Additionally, the first scheduling information may further indicate: an occasion for receiving the backscattering transmission, a duration for receiving the backscattering transmission, or a combination of above two items. In other words, the indication 215 includes the backscattering detection information, such as the reception occasion, reception duration, and which subband receiving backscattering transmission on.

In some embodiments, the indication 215 may comprise second scheduling information for transmitting an activation signal to the first apparatus and receiving the backscattering transmission. Additionally, the second scheduling information may further indicate: an occasion for transmitting the activation signal, a duration for transmitting the activation signal, an occasion for receiving the backscattering transmission, a duration for receiving the backscattering transmission, a source subband for transmitting the activation signal, or any combination of two or more the above-mentioned items.

Continuing with reference to Fig. 2, the first apparatus 110 receives an indication 230 of performing the frequency shift associated with a backscattering transmission of the first apparatus 110. In some embodiments, the indication 230 and the activation signal may be received 235 from the second apparatus 120, and the backscattering transmission is received by the second apparatus 120. For example, if a UE (i.e., the second apparatus 120) is the activator, the gNB may schedule the UE to send the appropriate OFDM subband to activate the A-IoT device. The activator selects some subcarriers of the OFDM symbol, i.e., subband, to transmit the activation signal. These subcarriers are also used to transmit the UL/DL data of a normal UE.

Correspondingly, the indication 215 is a first indication, the second apparatus 120 may transmit 225 a second indication (i.e., the indication 230) of performing the frequency shift associated with the backscattering transmission to the first apparatus 110. In addition, the second indication (i.e., the indication 230) may further indicate whether the frequency shift is an up conversion or a down conversion.

Additionally or alternatively, the second apparatus 120 may transmit an activation signal to the first apparatus 110, and the second apparatus 120 may further perform filtering on at least one subband adjacent to the target subband. To reduce the interference from the side lobe of OFDM signal, filter based OFDM may be considered to suppress the leakage power of OFDM subband.

In some embodiments, the indication 230 and the activation signal may be received 245 from the third apparatus 130, and the backscattering transmission is received by the second apparatus 120. In an example, if the gNB is the activator, the gNB may schedule and send the appropriate OFDM subband to activate the A-IoT device and indicate the A-IoT device to shift the signal to a prescriptive target subband.

Correspondingly, the indication 215 is a first indication, the third apparatus 130 may transmit 240 a second indication (i.e., the indication 230) to the first apparatus 110. In addition, the second indication (i.e., the indication 230) may further indicate whether the frequency shift is an up conversion or a down conversion.

Additionally or alternatively, the third apparatus 130 may transmit an activation signal to the first apparatus 110, and the third apparatus 130 may further perform filtering on at least one subband adjacent to the target subband.

The signal of backscattering transmission is the frequency shift of the in-band OFDM subband signal. In filtered based OFDM, the activator filters the subcarriers (or subband) adjacent to the guard band to suppress leakage power in the side lobe of OFDM. The guard band support to be embedded the waveform of the shifted activation and modulation signal from A-IoT device. In addition, it does not preclude that the A-IoT device to embed the signal in the in-band which is reserved to A-IoT communication. The subcarriers (or subband) adjacent to these reserved in-band tones also need be filtered by activator to suppress the leakage power. It is to be understood that the activator also is the transmitter of the UL/DL data transmission.

Fig. 4 illustrates an example of transmitter structure of filtered based OFDM according to some embodiments of the present disclosure. In a transmitter structure of filtered based OFDM, each subband is filtered when it converts to the OFDM signals. Different from such transmitter structure, in the filtered based OFDM of some embodiments of the present disclosure, not all subbands need to be filtered but only which adjacent to the target band of shifting, e.g., guard band or in-band tones which reserved to the A-IoT device backscattering signal. As shown in Fig. 4, the signals S_1k, S_2k, S_3k are input into the IDFT spreaders 410, 420, 430 respectively. The signals S_1k, S_2k, S_3k are converted into the OFDM signals. The OFDM signal x_1k is on the target band for the backscattering transmission, in which the signals S_1k being zero could reserve these carriers for the target band of backscattering transmission, and the OFDM signal x_2k on the subband adjacent to the guard band are filtered by the filter 440 with length L. For example, the subband (with three subcarriers) on the left side and the subband (with three subcarriers) on the right side of the guard band in Fig. 3 may be filtered to express the leakage power in the side lobe of OFDM.

Fig. 5 illustrates a simulation of the interference suppression of UF-OFDM according to some embodiments of the present disclosure. As shown in Fig. 5, the simulation curve 510 is the simulation of cyclic prefix OFDM (CP-OFDM) , i.e., the unfiltered OFDM signal, the simulation curve 520 is the simulation of UF-OFDM, i.e., the filtered OFDM signal. UF-OFDM filtering is performed per-subband. It can be seen that the interference on subbands adjacent to the guard band is reduced by 20dB.

Reference is made back to Fig. 2, based on the indication 230, the first apparatus 110 performs 250 the frequency shift of the activation signal to the target subband. In an example, the A-IoT device receives and filters the prescribed in-band OFDM symbols as the activation signal, the A-IoT device may then shift the activation signal to the guard band of OFDM.

Additionally or alternatively, the first apparatus 110 may modulate data on the frequency shifted activation signal based on OOK, ASK, or OOK and ASK. For example, the frequency shift is single sideband conversion, and the OOK/ASK on shifted signal is used to modulate the data of the A-IoT device. In another words, the single sideband frequency shift and OOK/ASK are used to modulate the data of the A-IoT device.

In some embodiments, the first apparatus 110 may be one of a plurality of first apparatuses activated by the activation signal. In an example, different types of A-IoT devices may be activated by different OFDM subband, which may be the fixed feature of the A-IoT device.

In some embodiments, the plurality of first apparatuses may have different capabilities on a frequency shift distance. In an example, different types of devices have the different frequency shift distance capability, which also may be the fixed feature of the device.

In some embodiments, the plurality of first apparatuses may shift the activation signal to a same subband or different target subbands. If there are a guard band and multiple reserved in-bands for A-IoT transmission, multiple A-IoT devices may rely on (be scheduled) the activation signal on the same subband and then the multiple A-IoT devices may the shift activation signal to different locations. In another use case, multiple A-IoT devices may rely on (be scheduled) the activation signal on the different subband and then the multiple A-IoT devices may the shift activation signal to the same locations.

Based on the frequency shifted activation signal on the target subband, the first apparatus 110 performs 255 the backscattering transmission. Based on the indication, the second apparatus 120 receives 270 the backscattering transmission 265 on the target subband from the first apparatus 110.

In general, through the example embodiments as shown in Fig. 2, a solution can be provided for e.g., type A/B A-IoT backscattering transmission co-existing with 3GPP systems the interference of the activation signal direct path to the backscattering path is avoided. The framework of the solution is to activate the A-IoT device with the NR OFDM signal, and the A-IoT device frequency shifts the backscattering signal to the guard band or reserved in-band of NR to reach the purpose of interference avoidance. Signaling aspects related to a method of realizing the frequency division multiplexing and the detailed implementation in the gNB are mainly considered. The solution may be applied in bi-static topologies of from a UE to an A-IoT device then to a gNB (corresponding to the NR UL transmission in Fig. 1C) , and from a gNB to an A-IoT device and then to a UE (corresponding to the NR DL transmission in Fig. 1D) . The solution may also be applied in monostatic topology to suppress the interference in the backscattering transmission.

The key point of this solution may be that A-IoT devices have the capability to frequency shift the activation signal and backscatter the reflective signal on the guard-band of OFDM. Such A-IoT deployments could be considered as activation on in-band of NR but backscattering on guard-band of NR. This is an in-band/out-band mixed scheme. The design of in-band/out-band mixed scheme coexistence with 3GPP technologies could improve the radio resource efficiency and avoid the impact of interference from activation signal.

Fig. 6 illustrates an example procedure of proposed solution according to some embodiments of the present disclosure. The procedure 600 may involve a device 601, a UE reader 602, a gNB activator 603, and a CN node 604. It is understood that the process 600 can be considered as a more specific example of the process 200 in Fig. 2. Thus, the device 601 in Fig. 6 may be an example of the first apparatus 110 in Fig. 2, the UE reader 602 in Fig. 6 may be an example of the second apparatus 120 in Fig. 2, and the gNB activator 603 in Fig. 6 may be an example of the third apparatus 130 in Fig. 2.

As shown in Fig. 6, at 610, when the device 601 is registered in the network, the CN node 604 stores some characteristics of the device 601 during the registration of the device 601. For example, if the device 601 has the frequency shift capability, the frequency shift distance is stored in the CN node 604.

At 615, once a service request for the device 601 is initiated, the CN node 604 sends a signaling, for example a query request of device service, to the gNB activator 603. As one parameter of the service request, the frequency shift distance is carried in the query request. The ID of the device 601 may be further carried in the query request.

At 620, the gNB activator 603 determines one or more UE as the reader UE (s) for this backscattering transmission. The network knows the association relationship between reader UEs and devices. The association information implies that UEs are aware of devices in their surroundings through a procedure established in advance.

At 625, the gNB activator 603 determines the activation subband of the activation signal (i.e., the source subband) and a target subband of the frequency shift. At 630, the gNB activator 603 sends scheduling information used for the backscattering detection to the UE reader 602. The scheduling information comprise a reception occasion, a reception duration and the target subband.

At 635, the gNB activator 603 sends the query indication to the device 601 in addition to the activation signal on the activation subband. The gNB activator 603 may indicate the device 601 to perform frequency shift in the query indication. In addition, whether to perform up conversion or down conversion may also be included in the query indication unless it is fixed in frequency shift capability of the device 601.

At 640, the device 601 applies the single sideband conversion and frequency shifts to the target suband (e.g., a guard band or in-band tones reserved to the device 601) . In addition, the OOK or ASK is used on shifted signal to modulate the data of device. In other words, frequency shift and OOK/ASK are used for modulating the data of device.

At 645, the device 601 backscatters the shifted and modulated signal on the target subband to the UE reader 602. At 650, the UE reader 602 detects the data of the device 601 according to the detection information. At 655, the UE reader 602 transmits the data to the gNB activator 603. At 660, the gNB activator 603 transmits the data to the CN node 604.

Fig. 7 illustrates an example procedure of proposed solution according to some embodiments of the present disclosure. The procedure 700 may involve a device 701, a UE activator/reader 702, a gNB 703, and a CN node 704. It is understood that the process 700 can be considered as a more specific example of the process 200 in Fig. 2. Thus, the device 701 in Fig. 7 may be an example of the first apparatus 110 in Fig. 2, the UE activator/reader 702 in Fig. 7 may be an example of the second apparatus 120 in Fig. 2, and the gNB 703 in Fig. 7 may be an example of the third apparatus 130 in Fig. 2.

As shown in Fig. 7, at 710, when the device 701 is registered in the network, the CN node 704 stores some characteristics of the device 701 (e.g., frequency shift capability) during the registration of the device 701.

At 715, once a service request for the device 701 is initiated, the CN node 704 sends a signaling, for example a query request of device service, to the gNB 703. As one parameter of the service request, the frequency shift distance is carried in the query request. The ID of the device 701 may be further carried in the query request.

At 720, the gNB 703 determines one or more UE as the activator and reader UE (s) for this backscattering transmission. The network knows the association relationship between activator/reader UEs and devices. The association information implies that UEs are aware of devices in their surroundings through a procedure established in advance.

At 725, the gNB 703 determines the activation subband of the activation signal (i.e., a source subband) and the target subband of the frequency shift. At 730, the gNB 703 sends scheduling information used for the backscattering detection to the UE activator/reader 702. The scheduling information comprise a reception occasion, a reception duration, the source subband and the target subband.

At 735, the UE activator/reader 702 sends the query indication to the device 701 in addition to the activation signal on the activation subband. The UE activator/reader 702 may indicate the device 701 to perform frequency shift in the query indication. In addition, whether to perform up conversion or down conversion may also be included in the query indication unless it is fixed in frequency shift capability of the device 701.

At 740, the device 701 applies the single sideband conversion and frequency shifts to the target suband (e.g., a guard band or in-band tones reserved to the device 701) . In addition, the OOK or ASK is used on shifted signal to modulate the data of device. In other words, frequency shift and OOK/ASK are used for modulating the data of device.

At 745, the device 701 backscatters the shifted and modulated signal on the target subband to the UE activator/reader 702. At 750, the UE activator/reader 702 detects the data of the device 701 according to the detection information. At 755, the UE activator/reader 702 transmits the data to the gNB 703. At 760, the gNB 703 transmits the data to the CN node 704.

Fig. 8 shows a flowchart of an example method 800 implemented at a first apparatus in accordance with some embodiments of the present disclosure. For the purpose of discussion, the method 800 will be described from the perspective of the first apparatus 110 with reference to Fig. 1A.

At block 810, the first apparatus receives an indication of performing a frequency shift associated with a backscattering transmission of the first apparatus. At block 820, the first apparatus 110 performs, based on the indication, the frequency shift of an activation signal to a target subband. At block 830, the first apparatus 110 performs the backscattering transmission based on the frequency shifted activation signal on the target subband.

In some embodiments, the indication and the activation signal may be received from a second apparatus or a third apparatus, and the backscattering transmission may be received by the second apparatus.

In some embodiments, the frequency shift may comprise a single sideband conversion. In some embodiments, the indication may further indicate whether the frequency shift is an up conversion or a down conversion.

In some embodiments, the first apparatus may further modulate data on the frequency shifted activation signal based on at least one of on-off keying (OOK) or amplitude shift keying (ASK) . In some embodiments, the target subband may comprise at least one of the following: a guard-band; or a reserved in-band.

In some embodiments, the first apparatus may further transmit, to a fourth apparatus, capability information on a frequency shift distance associated with the backscattering transmission. In some embodiments, capability information on a frequency shift distance may be transmitted during a registration procedure for the first apparatus. In some embodiments, the frequency shift distance may be fixed and limited number.

In some embodiments, the first apparatus may be one of a plurality of first apparatuses activated by the activation signal. In some embodiments, the plurality of first apparatuses may have different capabilities on a frequency shift distance. In some embodiments, the plurality of first apparatuses may shift the activation signal to a same subband or different target subbands.

In some embodiments, the first apparatus may comprise an ambient Internet of Things (A-IoT) apparatus. In some embodiments, the second apparatus may comprise a user equipment. In some embodiments, the third apparatus may comprise a base station.

Fig. 9 shows a flowchart of an example method 900 implemented at a second apparatus in accordance with some embodiments of the present disclosure. For the purpose of discussion, the method 900 will be described from the perspective of the second apparatus 120 with reference to Fig. 1A.

At block 910, the second apparatus receives, from a third apparatus, an indication for receiving a backscattering transmission of a first apparatus, wherein the indication indicates a target subband for a frequency shift associated with the backscattering transmission. At block 920, the second apparatus receives, based on the indication, the backscattering transmission on the target subband from the first apparatus.

In some embodiments, the indication may comprise first scheduling information for receiving the backscattering transmission. In some embodiments, the first scheduling information may further indicate at least one of the following: an occasion for receiving the backscattering transmission, or a duration for receiving the backscattering transmission.

In some embodiments, the indication may comprise second scheduling information for transmitting an activation signal to the first apparatus and receiving the backscattering transmission.

In some embodiments, the second scheduling information may further indicate at least one of the following: an occasion for transmitting the activation signal, a duration for transmitting the activation signal, an occasion for receiving the backscattering transmission; a duration for receiving the backscattering transmission, or a source subband for transmitting the activation signal.

In some embodiments, the indication is a first indication, and the second apparatus may further transmit, to the first apparatus, a second indication of performing the frequency shift associated with the backscattering transmission.

In some embodiments, the second indication may further indicate whether the frequency shift is an up conversion or a down conversion. In some embodiments, the target subband may comprise at least one of the following: a guard-band; or a reserved in-band.

In some embodiments, the second apparatus may transmit an activation signal to the first apparatus, and the second apparatus may further perform filtering on at least one subband adjacent to the target subband.

In some embodiments, the first apparatus may be one of a plurality of first apparatus activated by an activation signal. In some embodiments, the plurality of first apparatuses may have different capabilities on a frequency shift distance. In some embodiments, the plurality of first apparatus may shift the activation signal to a same subband or different target subbands.

Fig. 10 shows a flowchart of an example method 1000 implemented at a third apparatus in accordance with some embodiments of the present disclosure. For the purpose of discussion, the method 1000 will be described from the perspective of the third apparatus 130 with reference to Fig. 1A.

At block 1010, the third apparatus determines a target subband for a frequency shift associated with a backscattering transmission of a first apparatus. At block 1020, the third apparatus transmits, to a second apparatus, an indication for receiving the backscattering transmission, wherein the indication indicates the target subband.

In some embodiments, the indication may comprise first scheduling information for the second apparatus to receive the backscattering transmission. In some embodiments, the first scheduling information may further indicate at least one of the following: an occasion for receiving the backscattering transmission, or a duration for receiving the backscattering transmission.

In some embodiments, the indication may be a first indication, and the third apparatus may transmit, to the first apparatus, a second indication of performing the frequency shift associated with the backscattering transmission. In some embodiments, the second indication may further indicate whether the frequency shift is an up conversion or a down conversion.

In some embodiments, the indication may comprise second scheduling information for the second apparatus to transmit an activation signal and receive the backscattering transmission. In some embodiments, the second scheduling information may further indicate at least one of the following: an occasion for transmitting the activation signal, a duration for transmitting the activation signal, an occasion for receiving the backscattering transmission, a duration for receiving the backscattering transmission, or a source subband for transmitting the activation signal.

In some embodiments, the third apparatus may further receive, from a fourth apparatus, capability information of the first apparatus on a frequency shift distance associated with the backscattering transmission.

In some embodiments, the capability information may be received in a service request for the first apparatus. In some embodiments, the frequency shift distance may be a parameter of the service request.

In some embodiments, the target subband may be determined based on capability information of the first apparatus on a frequency shift distance associated with the backscattering transmission.

In some embodiments, the third apparatus may further determine a source subband of an activation signal for the first apparatus, based on capability information of the first apparatus on a frequency shift distance associated with the backscattering transmission.

In some embodiments, the target subband may comprise at least one of the following: a guard-band, or a reserved in-band. In some embodiments, the third apparatus may transmit an activation signal to the first apparatus, and the third apparatus may further perform filtering on at least one subband adjacent to the target subband.

In some embodiments, the first apparatus may be one of a plurality of first apparatuses activated by the activation signal, the plurality of first apparatuses may have different capabilities on a frequency shift distance, and the plurality of first apparatuses may shift the activation signal to a same subband or different target subbands.

In some embodiments, the first apparatus may comprise an ambient Internet of Things (A-IoT) apparatus, the second apparatus may comprise a user equipment, the third apparatus may comprise a base station, or the fourth apparatus may comprise a core network node.

Fig. 11 shows a flowchart of an example method 1100 implemented at a fourth apparatus in accordance with some embodiments of the present disclosure. For the purpose of discussion, the method 1100 will be described from the perspective of the fourth apparatus 140 with reference to Fig. 1A.

At block 1110, the fourth apparatus stores capability information of a first apparatus on a frequency shift distance associated with a backscattering transmission of the first apparatus. At block 1120, the fourth apparatus transmits, to a third apparatus, the capability information of the first apparatus.

In some embodiments, the capability information may be stored during a registration procedure for the first apparatus. In some embodiments, the capability information may be transmitted in a service request for the first apparatus, and the frequency shift distance may be a parameter of the service request.

In some embodiments, the first apparatus may comprise an ambient Internet of Things (A-IoT) apparatus. In some embodiments, the third apparatus may comprise a base station. In some embodiments, the fourth apparatus may comprise a core network node.

In some embodiments, a first apparatus capable of performing any of the method 800 (for example, the first apparatus 110) is provided. The first apparatus may comprise means for performing the respective steps of the method 800. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module.

In some embodiments, the first apparatus comprises means for receiving an indication of performing a frequency shift associated with a backscattering transmission of the first apparatus, means for performing the frequency shift of an activation signal to a target subband based on the indication, and means for performing the backscattering transmission based on the frequency shifted activation signal on the target subband.

In some embodiments, the indication and the activation signal may be received from a second apparatus or a third apparatus; and the backscattering transmission may be received by the second apparatus.

In some embodiments, the frequency shift may comprise a single sideband conversion; or the indication may further indicate whether the frequency shift is an up conversion or a down conversion.

In some embodiments, the first apparatus may further comprise means for modulating data on the frequency shifted activation signal based on at least one of on-off keying (OOK) or amplitude shift keying (ASK) . In some embodiments, the target subband may comprise at least one of the following: a guard-band; or a reserved in-band.

In some embodiments, the first apparatus may further comprise means for transmitting, to a fourth apparatus, capability information on a frequency shift distance associated with the backscattering transmission.

In some embodiments, capability information on a frequency shift distance may be transmitted during a registration procedure for the first apparatus. In some embodiments, the frequency shift distance may be fixed and limited number.

In some embodiments, the first apparatus may further comprise an ambient Internet of Things (A-IoT) device. In some embodiments, the second apparatus may comprise a user equipment. In some embodiments, the third apparatus may comprise a base station.

In some embodiments, the first apparatus further comprises means for performing other steps in some embodiments of the method 800. In some embodiments, the means comprises at least one processor; and at least one memory including computer program code, the at least one memory and computer program code configured to, with the at least one processor, cause the performance of the apparatus.

In some embodiments, a second apparatus capable of performing any of the method 900 (for example, the second apparatus 120) is provided. The apparatus may comprise means for performing the respective steps of the method 900. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module.

In some embodiments, the second apparatus comprises means for receiving, from a third apparatus, an indication for receiving a backscattering transmission of a first apparatus, wherein the indication indicates a target subband for a frequency shift associated with the backscattering transmission, and means for receiving the backscattering transmission on the target subband from the first apparatus based on the indication.

In some embodiments, the indication is a first indication, and the apparatus may further comprise means for transmitting, to the first apparatus, a second indication of performing the frequency shift associated with the backscattering transmission.

In some embodiments, the second apparatus transmits an activation signal to the first apparatus, and the second apparatus may further comprise means for performing filtering on at least one subband adjacent to the target subband.

In some embodiments, the first apparatus may comprise an ambient Internet of Things (A-IoT) device, the second apparatus may comprise a user equipment, or the third apparatus may comprise a base station.

In some embodiments, the second apparatus further comprises means for performing other steps in some embodiments of the method 900. In some embodiments, the means comprises at least one processor; and at least one memory including computer program code, the at least one memory and computer program code configured to, with the at least one processor, cause the performance of the apparatus.

In some embodiments, a third apparatus capable of performing any of the method 900 (for example, the third apparatus 130) is provided. The apparatus may comprise means for performing the respective steps of the method 1000. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module.

In some embodiments, the third apparatus comprises means for determining a target subband for a frequency shift associated with a backscattering transmission of a first apparatus, and means for transmitting, to a second apparatus, an indication for receiving the backscattering transmission, wherein the indication indicates the target subband.

In some embodiments, the indication may be a first indication, and the apparatus may further comprise means for transmitting, to the first apparatus, a second indication of performing the frequency shift associated with the backscattering transmission.

In some embodiments, the second indication may further indicate whether the frequency shift is an up conversion or a down conversion. In some embodiments, the indication may comprise second scheduling information for the second apparatus to transmit an activation signal and receive the backscattering transmission.

In some embodiments, the second scheduling information may further indicate at least one of the following: an occasion for transmitting the activation signal, a duration for transmitting the activation signal, an occasion for receiving the backscattering transmission, a duration for receiving the backscattering transmission, or a source subband for transmitting the activation signal.

In some embodiments, the third apparatus may further comprise means for receiving, from a fourth apparatus, capability information of the first apparatus on a frequency shift distance associated with the backscattering transmission.

In some embodiments, the capability information may be received in a service request for the first apparatus, and the frequency shift distance may be a parameter of the service request.

In some embodiments, the third apparatus may further comprise means for determining a source subband of an activation signal for the first apparatus, based on capability information of the first apparatus on a frequency shift distance associated with the backscattering transmission. In some embodiments, the target subband may comprise at least one of the following: a guard-band, or a reserved in-band.

In some embodiments, the third apparatus may transmit an activation signal to the first apparatus, the third apparatus may further comprise means for perform filtering on at least one subband adjacent to the target subband.

In some embodiments, the first apparatus may comprise an ambient Internet of Things (A-IoT) device. In some embodiments, the second apparatus may comprise a user equipment. In some embodiments, the third apparatus may comprise a base station, or the fourth apparatus may comprise a core network node.

In some embodiments, the third apparatus further comprises means for performing other steps in some embodiments of the method 1000. In some embodiments, the means comprises at least one processor; and at least one memory including computer program code, the at least one memory and computer program code configured to, with the at least one processor, cause the performance of the apparatus.

In some embodiments, a fourth apparatus capable of performing any of the method 1100 (for example, the fourth apparatus 140) is provided. The apparatus may comprise means for performing the respective steps of the method 1100. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module.

In some embodiments, the fourth apparatus comprises means for storing capability information of a first apparatus on a frequency shift distance associated with a backscattering transmission of the first apparatus, and means for transmitting, to a third apparatus, the capability information of the first apparatus.

In some embodiments, the first apparatus may comprise an ambient Internet of Things (A-IoT) device, the third apparatus may comprise a base station, or the fourth apparatus may comprise a core network node.

In some embodiments, the fourth apparatus further comprises means for performing other steps in some embodiments of the method 1100. In some embodiments, the means comprises at least one processor; and at least one memory including computer program code, the at least one memory and computer program code configured to, with the at least one processor, cause the performance of the apparatus.

FIG. 12 is a simplified block diagram of a device 1200 that is suitable for implementing embodiments of the present disclosure. The device 600 may be provided to implement the communication device, for example a first apparatus 110, a second apparatus 120, a third apparatus 130, or a fourth apparatus 140 as shown in Fig. 1A. As shown, the device 1200 includes one or more processors 1210, one or more memories 1220 coupled to the processor 1210, and one or more communication modules 1240 coupled to the processor 1210.

The communication modules 1240 is for bidirectional communications. The communication modules 1240 has at least one antenna to facilitate communication. The communication interface may represent any interface that is necessary for communication with other network elements.

The processor 1210 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 1200 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.

The memory 1220 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) 1224, 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) 1222 and other volatile memories that will not last in the power-down duration.

A computer program 1230 includes computer executable instructions that are executed by the associated processor 1210. The program 1230 may be stored in the ROM 1224. The processor 1210 may perform any suitable actions and processing by loading the program 1230 into the RAM 1222.

The embodiments of the present disclosure may be implemented by means of the program 1230 so that the device 1200 may perform any process of example embodiments of the disclosure as discussed with reference to Figs. 2 to 11. The embodiments of the present disclosure may also be implemented by hardware or by a combination of software and hardware.

In some embodiments, the program 1230 may be tangibly contained in a computer readable medium which may be included in the device 1200 (such as in the memory 1220) or other storage devices that are accessible by the device 1200. The device 1200 may load the program 1230 from the computer readable medium to the RAM 1222 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. 13 shows an example of the computer readable medium 1300 in form of CD or DVD. The computer readable medium has the program 1230 stored thereon.

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.

Example embodiments of 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 800, 900, 1000, and 1100 as described above with reference to Figs. 8-11. 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. Machine-executable 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.

Program code for carrying out methods of example embodiments 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.

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.

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) .

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.

Although example embodiments of the present disclosure have been described in languages specific to structural features and/or methodological acts, it is to be understood that the example embodiments of 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

A first apparatus comprising:

at least one processor; and

at least one memory storing instructions that, when executed by the at least one processor, cause the first apparatus at least to:

receive an indication of performing a frequency shift associated with a backscattering transmission of the first apparatus;

perform, based on the indication, the frequency shift of an activation signal to a target subband; and

perform the backscattering transmission based on the frequency shifted activation signal on the target subband.
The first apparatus of claim 1, wherein one of the following:

the indication and the activation signal are received from a second apparatus or a third apparatus, and the backscattering transmission is received by the second apparatus.
The first apparatus of claim 1 or 2, wherein capability information on a frequency shift distance is transmitted during a registration procedure for the first apparatus.
The first apparatus of claim 3, wherein the frequency shift distance is fixed and limited number.
The first apparatus of any of claims 1-4, wherein:

the first apparatus is one of a plurality of first apparatuses activated by the activation signal;

the plurality of first apparatuses have different capabilities on a frequency shift distance; and

the plurality of first apparatuses shift the activation signal to a same subband or different target subbands.
A second apparatus comprising:

at least one processor; and

at least one memory storing instructions that, when executed by the at least one processor, cause the second apparatus at least to:

receive, from a third apparatus, an indication for receiving a backscattering transmission of a first apparatus, wherein the indication indicates a target subband for a frequency shift associated with the backscattering transmission; and

receive, based on the indication, the backscattering transmission on the target subband from the first apparatus.
The second apparatus of claim 6, wherein the indication comprises first scheduling information for receiving the backscattering transmission.
The second apparatus of claim 7, wherein the first scheduling information further indicates at least one of the following:

an occasion for receiving the backscattering transmission; or

a duration for receiving the backscattering transmission.
The second apparatus of claim 6, wherein the indication comprises second scheduling information for transmitting an activation signal to the first apparatus and receiving the backscattering transmission.
The second apparatus of claim 9, wherein the second scheduling information further indicates at least one of the following:

an occasion for transmitting the activation signal;

a duration for transmitting the activation signal;

an occasion for receiving the backscattering transmission;

a duration for receiving the backscattering transmission; or

a source subband for transmitting the activation signal.
The second apparatus of claim 6, 9 or 10, wherein the indication is a first indication, and the second apparatus is further caused to:

transmit, to the first apparatus, a second indication of performing the frequency shift associated with the backscattering transmission.
The second apparatus of any of claims 6-11, wherein the second apparatus transmits an activation signal to the first apparatus, and the second apparatus is further caused to:

perform filtering on at least one subband adjacent to the target subband.
The second apparatus of any of claims 6-12, wherein:

the first apparatus is one of a plurality of first apparatuses activated by an activation signal;

the plurality of first apparatuses have different capabilities on a frequency shift distance; and

the plurality of first apparatuses shift the activation signal to a same subband or different target subbands.
A third apparatus comprising:

at least one processor; and

at least one memory storing instructions that, when executed by the at least one processor, cause the third apparatus at least to:

determine a target subband for a frequency shift associated with a backscattering transmission of a first apparatus; and

transmit, to a second apparatus, an indication for receiving the backscattering transmission, wherein the indication indicates the target subband.
The third apparatus of claim 14, wherein the indication comprises first scheduling information for the second apparatus to receive the backscattering transmission.
The third apparatus of claim 15, wherein the first scheduling information further indicates at least one of the following:

an occasion for receiving the backscattering transmission; or

a duration for receiving the backscattering transmission.
The third apparatus of any of claims 14-16, wherein the indication is a first indication, and the third apparatus is further caused to:

transmit, to the first apparatus, a second indication of performing the frequency shift associated with the backscattering transmission.
The third apparatus of claim 14, wherein the indication comprises second scheduling information for the second apparatus to transmit an activation signal and receive the backscattering transmission.
The third apparatus of claim 18, wherein the second scheduling information further indicates at least one of the following:

an occasion for transmitting the activation signal;

a duration for transmitting the activation signal;

an occasion for receiving the backscattering transmission;

a duration for receiving the backscattering transmission; or

a source subband for transmitting the activation signal.
The third apparatus of any of claims 14-19, wherein the third apparatus is further caused to:

receive, from a fourth apparatus, capability information of the first apparatus on a frequency shift distance associated with the backscattering transmission.
The third apparatus of any of claims 14-19, wherein the target subband is determined based on capability information of the first apparatus on a frequency shift distance associated with the backscattering transmission.
The third apparatus of any of claims 14-21, wherein the third apparatus is further caused to:

determine a source subband of an activation signal for the first apparatus, based on capability information of the first apparatus on a frequency shift distance associated with the backscattering transmission.
The third apparatus of any of claims 14-22, wherein the third apparatus transmits an activation signal to the first apparatus, and the third apparatus is further caused to:

perform filtering on at least one subband adjacent to the target subband.
The third apparatus of any of claims 14-23, wherein:

the first apparatus is one of a plurality of first apparatuses activated by the activation signal;

the plurality of first apparatuses have different capabilities on a frequency shift distance; and

the plurality of first apparatuses shift the activation signal to a same subband or different target subbands.
A fourth apparatus comprising:

at least one processor; and

at least one memory storing instructions that, when executed by the at least one processor, cause the fourth apparatus at least to:

store capability information of a first apparatus on a frequency shift distance associated with a backscattering transmission of the first apparatus; and

transmit, to a third apparatus, the capability information of the first apparatus.
The fourth apparatus of claim 25, wherein:

the capability information is transmitted in a service request for the first apparatus, and

the frequency shift distance is a parameter of the service request.
A method comprising:

receiving, at a first apparatus, an indication of performing a frequency shift associated with a backscattering transmission of the first apparatus;

performing, based on the indication, the frequency shift of an activation signal to a target subband; and

performing the backscattering transmission based on the frequency shifted activation signal on the target subband.
A method comprising:

receiving, at a second apparatus from a third apparatus, an indication for receiving a backscattering transmission of a first apparatus, wherein the indication indicates a target subband for a frequency shift associated with the backscattering transmission; and

receiving, based on the indication, the backscattering transmission on the target subband from the first apparatus.
A method comprising:

determining, at a third apparatus, a target subband for a frequency shift associated with a backscattering transmission of a first apparatus; and

transmitting, to a second apparatus, an indication for receiving the backscattering transmission, wherein the indication indicates the target subband.
A first apparatus comprising:

means for receiving an indication of performing a frequency shift associated with a backscattering transmission of the first apparatus;

means for performing, based on the indication, the frequency shift of an activation signal to a target subband; and

means for performing the backscattering transmission based on the frequency shifted activation signal on the target subband.
A second apparatus comprising:

means for receiving, from a third apparatus, an indication for receiving a backscattering transmission of a first apparatus, wherein the indication indicates a target subband for a frequency shift associated with the backscattering transmission; and

means for receiving, based on the indication, the backscattering transmission on the target subband from the first apparatus.
A third apparatus comprising:

means for determining a target subband for a frequency shift associated with a backscattering transmission of a first apparatus; and

means for transmitting, to a second apparatus, an indication for receiving the backscattering transmission, wherein the indication indicates the target subband.
A non-transitory computer readable medium comprising program instructions that, when executed by an apparatus, cause the apparatus to perform at least the method of any of claims 27-29.