Frequency shift in low power devices

Abstract

Methods, systems, and devices for wireless communication are described. A radio frequency identification (RFID) tag may receive continuous waves from a first wireless device via a first set of frequency resources and according to a set of transmit parameters. In some examples, the continuous wave may include a continuous waveform for activating the RFID tag. Based on receiving the continuous waveform for activation, the RFID tag may modulate the continuous wave with data and transmit a backscattered signal of the continuous wave via a second set of frequency resources based on modulating the continuous wave with data, where the second set of frequency resources may be offset in frequency relative to the first set of frequency resources. In some examples, the backscatter signal may be transmitted to a first wireless device. In some other examples, the backscatter signal may be transmitted to a third wireless device.

Description

Technical Field

[0001] The following relates to wireless communications, including frequency shifting in low-power devices. Background Art

[0002] Wireless communication systems are widely deployed to provide various types of communication content, such as voice, video, packet data, messaging, broadcast, and the like. These systems may be able to support communication with multiple users by sharing available system resources (e.g., time, frequency, and power). Examples of such multiple access systems include fourth generation (4G) systems (such as long term evolution (LTE) systems, advanced LTE (LTE-A) systems, or LTE-A Pro systems) and fifth generation (5G) systems (which may be referred to as new radio (NR) systems). These systems may employ techniques such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), or discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-S-OFDM). A wireless multiple access communication system may include one or more base stations, each of which supports wireless communication of communication devices, which may be referred to as user equipment (UE). In some wireless communication systems, a UE may communicate with or may be a radio frequency identification (RFID) tag. Summary of the Invention

[0003] The described technology relates to improved methods, systems, devices, and apparatuses for supporting frequency shifting in low-power devices. For example, the described technology provides a radio frequency identification (RFID) tag to perform frequency shifting in order to transmit a backscattered signal. For example, the RFID tag may receive a continuous wave from a first wireless device via a first set of frequency resources, wherein the continuous wave may include a continuous waveform for activating the RFID tag. Based on receiving the continuous waveform for activation, the RFID tag may modulate the continuous wave (for conveying data) and transmit a backscattered signal of the continuous wave via a second set of frequency resources, the continuous wave including or indicating the modulated data. In such examples, the second set of frequency resources may be offset in frequency relative to the first set of frequency resources.

[0004] A method for wireless communication at a first wireless device is described. The method may include transmitting a continuous wave to a second wireless device (e.g., an RFID tag) via a first set of frequency resources and in accordance with a set of transmission parameters, wherein the continuous wave comprises a continuous waveform for activating the second wireless device; and receiving a backscattered signal of the continuous wave from the second wireless device via a second set of frequency resources, wherein the second set of frequency resources is offset in frequency relative to the first set of frequency resources.

[0005] An apparatus for wireless communication at a first wireless device is described. The apparatus may include a processor, a memory coupled to the processor, and instructions stored in the memory. The instructions are executable by the processor to cause the apparatus to: transmit a continuous wave to a second wireless device via a first set of frequency resources and in accordance with a set of transmission parameters, wherein the continuous wave comprises a continuous waveform for activating the second wireless device; and receive a backscattered signal of the continuous wave from the second wireless device via a second set of frequency resources, wherein the second set of frequency resources is offset in frequency relative to the first set of frequency resources.

[0006] Another apparatus for wireless communication at a first wireless device is described. The apparatus may include: means for transmitting a continuous wave to a second wireless device via a first set of frequency resources and in accordance with a set of transmit parameters, wherein the continuous wave comprises a continuous waveform for activating the second wireless device; and means for receiving a backscattered signal of the continuous wave from the second wireless device via a second set of frequency resources, wherein the second set of frequency resources is offset in frequency relative to the first set of frequency resources.

[0007] A non-transitory computer-readable medium storing code for wireless communication at a first wireless device is described. The code may include instructions executable by a processor to: transmit a continuous wave to a second wireless device via a first set of frequency resources and in accordance with a set of transmission parameters, wherein the continuous wave comprises a continuous waveform for activating the second wireless device; and receive a backscattered signal of the continuous wave from the second wireless device via a second set of frequency resources, wherein the second set of frequency resources is offset in frequency relative to the first set of frequency resources.

[0008] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for performing the following actions: receiving a message from a network entity, the message including an indication to communicate with the second wireless device, a number of resource blocks (RBs) to be used in the first set of frequency resources, a target transmit power, a target receive power, a classification of the second wireless device, or a combination thereof, wherein sending the continuous wave via the first set of frequency resources may be based on the message.

[0009] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for receiving a message including an ability of the second wireless device to perform a frequency shift, wherein receiving the backscatter signal via the second set of frequency resources that is shifted in frequency relative to the first set of frequency resources may be based on the message.

[0010] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for receiving a message indicating a frequency shift value for the second set of frequency resources, wherein the second set of frequency resources may be offset in frequency relative to the first set of frequency resources based on the frequency shift value.

[0011] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for sending an indication of the first set of frequency resources, the frequency shift value, or both for the continuous wave to a third wireless device.

[0012] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for performing channel estimation of a channel between the first wireless device and the second wireless device based on the continuous wave; and performing time and frequency correction to decode the backscattered signal based on performing the channel estimation.

[0013] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the first set of frequency resources may be continuous in frequency; and the second set of frequency resources may be offset in frequency relative to the first set of frequency resources by a frequency shift value that may be greater than the number of RBs of the first set of frequency resources.

[0014] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the first set of frequency resources may be non-contiguous in frequency; and the second set of frequency resources may be offset in frequency relative to the first set of frequency resources by a frequency shift value that may be smaller than the interval between RBs of the first set of frequency resources.

[0015] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the number of RBs in the first frequency resource set may be based on the transmit parameter set, and the transmit parameter set includes a target transmit power, a target receive power, a power spectral density (PSD) constraint, or a combination thereof.

[0016] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the number of RBs in the first set of frequency resources may be based on a classification of the second wireless device.

[0017] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the classification of the second wireless device includes one of passive classification, semi-passive classification, semi-active classification, or active classification.

[0018] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the second set of frequency resources may be offset in frequency relative to the first set of frequency resources based on a frequency shift value, and the frequency shift value may be preconfigured at the first wireless device.

[0019] A method for wireless communication at a second wireless device is described. The method may include receiving a continuous wave via a first set of frequency resources and according to a set of transmit parameters, wherein the continuous wave includes a continuous waveform for activating the second wireless device; modulating the continuous wave with data based on the continuous waveform for activating the second wireless device; and transmitting a backscattered signal of the continuous wave via a second set of frequency resources based on modulating the continuous wave with the data, wherein the second set of frequency resources is offset in frequency relative to the first set of frequency resources.

[0020] An apparatus for wireless communication at a second wireless device is described. The apparatus may include a processor, a memory coupled to the processor, and instructions stored in the memory. The instructions are executable by the processor to cause the apparatus to: receive a continuous wave via a first set of frequency resources and in accordance with a set of transmit parameters, wherein the continuous wave includes a continuous waveform for activating the second wireless device; modulate the continuous wave with data based on the continuous waveform for activating the second wireless device; and transmit a backscattered signal of the continuous wave via a second set of frequency resources based on the modulation of the continuous wave with the data, wherein the second set of frequency resources is offset in frequency relative to the first set of frequency resources.

[0021] Another apparatus for wireless communication at a second wireless device is described. The apparatus may include: means for receiving a continuous wave via a first set of frequency resources and in accordance with a set of transmit parameters, wherein the continuous wave includes a continuous waveform for activating the second wireless device; means for modulating the continuous wave with data based on the continuous waveform for activating the second wireless device; and means for transmitting a backscattered signal of the continuous wave via a second set of frequency resources based on modulating the continuous wave with the data, wherein the second set of frequency resources is offset in frequency relative to the first set of frequency resources.

[0022] A non-transitory computer-readable medium storing code for wireless communication at a second wireless device is described. The code may include instructions executable by a processor to: receive a continuous wave via a first set of frequency resources and according to a set of transmit parameters, wherein the continuous wave includes a continuous waveform for activating the second wireless device; modulate the continuous wave with data based on the continuous waveform for activating the second wireless device; and transmit a backscatter signal of the continuous wave via a second set of frequency resources based on modulating the continuous wave with the data, wherein the second set of frequency resources is offset in frequency relative to the first set of frequency resources.

[0023] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for transmitting a message indicating an ability to perform a frequency shift, wherein transmitting the backscatter signal via the second set of frequency resources that is offset in frequency relative to the first set of frequency resources may be based on the ability to perform the frequency shift.

[0024] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the continuous wave can be received from the first wireless device and the backscattered signal can be transmitted to the third wireless device.

[0025] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the second set of frequency resources may be offset in frequency relative to the first set of frequency resources based on a frequency shift value.

[0026] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the number of RBs in the first frequency resource set may be based on the transmit parameter set, and the transmit parameter set includes a target transmit power, a target receive power, a PSD constraint, or a combination thereof.

[0027] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the number of RBs in the first set of frequency resources may be based on a classification of the second wireless device.

[0028] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the classification of the second wireless device includes one of passive classification, semi-passive classification, semi-active classification, or active classification.

[0029] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the first set of frequency resources may be continuous in frequency; and the second set of frequency resources may be offset in frequency relative to the first set of frequency resources by a frequency shift value that may be greater than the number of RBs of the first set of frequency resources.

[0030] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the first set of frequency resources may be non-contiguous in frequency; and the second set of frequency resources may be offset in frequency relative to the first set of frequency resources by a frequency shift value that may be smaller than the interval between RBs of the first set of frequency resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 An example of a wireless communication system supporting frequency shifting in low power devices according to one or more aspects of the present disclosure is illustrated.

[0032] Figure 2 An example of a wireless communication system supporting frequency shifting in low power devices according to one or more aspects of the present disclosure is illustrated.

[0033] Figure 3 and Figure 4 An example of a resource allocation map supporting frequency shifting in a low power device according to one or more aspects of the present disclosure is illustrated.

[0034] Figure 5 An example of a process flow for supporting frequency shifting in a low power device according to one or more aspects of the present disclosure is illustrated.

[0035] Figure 6 and Figure 7 A block diagram illustrating a device supporting frequency shifting in a low power device according to one or more aspects of the present disclosure is illustrated.

[0036] Figure 8 A block diagram illustrating a communication manager supporting frequency shifting in a low power device according to one or more aspects of the present disclosure is illustrated.

[0037] Figure 9 A diagram illustrating a system including a device supporting frequency shifting in a low power device in accordance with one or more aspects of the present disclosure is illustrated.

[0038] Figures 10 to 13 A flow chart illustrating a method of supporting frequency shifting in a low power device according to one or more aspects of the present disclosure is illustrated. DETAILED DESCRIPTION

[0039] In some wireless communication systems, a wireless device (e.g., such as a user equipment (UE) or a network entity) may communicate with one or more low-power devices (e.g., such as one or more radio frequency identification (RFID) tags, which may also be referred to as UEs). To facilitate such communication, the wireless device may transmit a continuous wave (e.g., a forward link signal) to the RFID tag, where the RFID tag may use the continuous wave to power or activate the RFID tag and transmit a backscattered signal to the wireless device. However, in some cases, power spectral density (PSD) constraints within a single frequency band (e.g., carrier, subcarrier, frequency range) may limit the total transmit power of the continuous wave, resulting in a limited communication coverage area. For example, a wireless device may transmit a continuous wave to an RFID tag according to the PSD constraints. However, due to one or more conditions (e.g., the distance between the wireless device and the RFID tag, obstacles, etc.), the power of the continuous wave may be insufficient to permit device activation, enable backscatter communication, or both. Consequently, the area over which the wireless device and the RFID tag can communicate may be limited, resulting in inefficient communication.

[0040] The techniques described herein may enable a wireless device to communicate with an RFID tag using an increased number of resource blocks (RBs) (e.g., subcarriers, frequency resources). For example, a wireless device may transmit a continuous wave using a different number of RBs to meet the RFID tag's target transmit and receive power while remaining within PSD constraints. To avoid interference caused by using an increased number of RBs, the RFID tag may perform a frequency shift on the backscattered signal so that the frequency resources used when transmitting the continuous wave differ from the frequency resources used when transmitting the backscattered signal (e.g., such that the frequency resources do not overlap, partially overlap, or are modulated according to frequency shift keying (FSK) with respect to frequency shifting). In some examples, the RFID tag may transmit capability information to the wireless device indicating the ability to perform frequency shifting and indicating a frequency shift value or a range of frequency shift values, such as a minimum frequency shift value, a maximum frequency shift value, or a discrete number of frequency shift values. In this way, communication between the RFID tag and the wireless device may have a larger communication area while also accounting for interference.

[0041] Various aspects of the present disclosure are first described in the context of a wireless communication system. Aspects of the present disclosure are further described in the context of resource allocation diagrams and process flows. Aspects of the present disclosure are further illustrated and described with reference to apparatus diagrams, system diagrams, and flow diagrams related to frequency shifting in low-power devices.

[0042] Figure 1An example of a wireless communication system 100 that supports frequency shifting in low-power devices according to one or more aspects of the present disclosure is illustrated. The wireless communication system 100 may include one or more network entities 105, one or more UEs 115, and a core network 130. In some examples, the wireless communication system 100 may be a Long Term Evolution (LTE) network, an Advanced LTE (LTE-A) network, an LTE-A Pro network, a New Radio (NR) network, or a network operating according to other systems and radio technologies, including future systems and radio technologies not explicitly mentioned herein.

[0043] The network entities 105 may be dispersed throughout a geographic area to form the wireless communication system 100 and may include devices that take different forms or have different capabilities. In various examples, the network entities 105 may be referred to as network elements, mobility elements, radio access network (RAN) nodes, or network equipment, among other nomenclature. In some examples, the network entities 105 and the UEs 115 may communicate wirelessly via one or more communication links 125 (e.g., radio frequency (RF) access links). For example, the network entities 105 may support a coverage area 110 (e.g., a geographic coverage area) within which the UEs 115 and the network entities 105 may establish one or more communication links 125. The coverage area 110 may be an example of a geographic area within which the network entities 105 and the UEs 115 may support signal communication according to one or more radio access technologies (RATs).

[0044] The UEs 115 may be dispersed throughout the coverage area 110 of the wireless communication system 100, and each UE 115 may be stationary or mobile or both stationary and mobile at different times. The UEs 115 may be devices that take different forms or have different capabilities. Figure 1 Some example UEs 115 are illustrated in FIG. The UEs 115 described herein may be capable of supporting communication with various types of devices such as Figure 1 Other UEs 115 or network entities 105 are shown communicating.

[0045] As described herein, a node of the wireless communication system 100 (which may be referred to as a network node or wireless node) may be a network entity 105 (e.g., any network entity described herein), a UE 115 (e.g., any UE described herein), a network controller, an apparatus, a device, a computing system, one or more components, or another suitable processing entity configured to perform any of the techniques described herein. For example, the node may be a UE 115. As another example, the node may be a network entity 105. As another example, a first node may be configured to communicate with a second node or a third node. In one aspect of this example, the first node may be a UE 115, the second node may be a network entity 105, and the third node may be a UE 115. In another aspect of this example, the first node may be a UE 115, the second node may be a network entity 105, and the third node may be a network entity 105. In other aspects of this example, the first node, the second node, and the third node may be different relative to these examples. Similarly, references to UE 115, network entity 105, apparatus, device, computing system, etc. may include disclosure of UE 115, network entity 105, apparatus, device, computing system, etc. as nodes. For example, a disclosure that UE 115 is configured to receive information from network entity 105 also discloses that the first node is configured to receive information from the second node.

[0046] In some examples, network entities 105 can communicate with core network 130, with each other, or both. For example, network entities 105 can communicate with core network 130 via one or more backhaul communication links 120 (e.g., according to S1, N2, N3, or other interface protocols). In some examples, network entities 105 can communicate with each other via backhaul communication links 120 (e.g., according to X2, Xn, or other interface protocols), directly (e.g., directly between network entities 105) or indirectly (e.g., via core network 130). In some examples, network entities 105 can communicate with each other via midhaul communication links 162 (e.g., according to a midhaul interface protocol) or fronthaul communication links 168 (e.g., according to a fronthaul interface protocol), or any combination thereof. Backhaul communication links 120, midhaul communication links 162, or fronthaul communication links 168 can be or include one or more wired links (e.g., electrical links, fiber optic links), one or more wireless links (e.g., radio links, wireless optical links), etc., or various combinations thereof. UE 115 may communicate with core network 130 via communication link 155 .

[0047] One or more of the network entities 105 described herein may include or may be referred to as a base station 140 (e.g., a transceiver base station, a radio base station, an NR base station, an access point, a radio transceiver, a Node B, an eNodeB (eNB), a next-generation Node B, or a gigabit Node B (any of which may be referred to as a gNB), a 5G NB, a next-generation eNB (ng-eNB), a Home Node B, a Home evolved Node B, or other suitable terminology). In some examples, the network entity 105 (e.g., a base station 140) may be implemented in a converged (e.g., monolithic, stand-alone) base station architecture that may be configured to utilize a protocol stack that is physically or logically integrated within a single network entity 105 (e.g., a single RAN node, such as the base station 140).

[0048] In some examples, the network entity 105 can be implemented in a disaggregated architecture (e.g., a disaggregated base station architecture, a disaggregated RAN architecture) that can be configured to utilize a protocol stack that is physically or logically distributed between two or more network entities 105, such as an integrated access backhaul (IAB) network, an open RAN (O-RAN) (e.g., a network configuration sponsored by the O-RAN Alliance), or a virtualized RAN (vRAN) (e.g., a cloud RAN (C-RAN)). For example, the network entity 105 can include one or more of the following: a central unit (CU) 160, a distributed unit (DU) 165, a radio unit (RU) 170, a RAN intelligent controller (RIC) 175 (e.g., a near real-time RIC (near RT RIC), a non-real-time RIC (non-RT RIC)), a service management and orchestration (SMO) 180 system, or any combination thereof. The RU 170 may also be referred to as a radio head, smart radio head, remote radio head (RRH), remote radio unit (RRU), or transmit receive point (TRP). One or more components of the network entity 105 in the disaggregated RAN architecture may be co-located, or one or more components of the network entity 105 may be located in distributed locations (e.g., separate physical locations). In some examples, one or more network entities 105 of the disaggregated RAN architecture may be implemented as virtual units (e.g., virtual CU (VCU), virtual DU (VDU), virtual RU (VRU)).

[0049] The functional split between CU 160, DU 165, and RU 170 is flexible and can support different functionalities depending on which functions (e.g., network layer functions, protocol layer functions, baseband functions, RF functions, and any combination thereof) are performed at CU 160, DU 165, or RU 170. For example, a functional split of the protocol stack can be employed between CU 160 and DU 165 such that CU 160 can support one or more layers of the protocol stack and DU 165 can support one or more different layers of the protocol stack. In some examples, CU 160 can host higher protocol layer (e.g., Layer 3 (L3), Layer 2 (L2)) functionality and signaling (e.g., Radio Resource Control (RRC), Service Data Adaptation Protocol (SDAP), Packet Data Convergence Protocol (PDCP)). The CU 160 may be connected to one or more DUs 165 or RUs 170, and the one or more DUs 165 or RUs 170 may host lower protocol layers, such as Layer 1 (L1) (e.g., physical (PHY) layer) or L2 (e.g., radio link control (RLC) layer, medium access control (MAC) layer) functionality and signaling, and may each be at least partially controlled by the CU 160. Additionally or alternatively, a functional split of the protocol stack may be employed between the DUs 165 and RUs 170, such that the DUs 165 may support one or more layers of the protocol stack and the RUs 170 may support one or more different layers of the protocol stack. The DUs 165 may support one or more different cells (e.g., via one or more RUs 170). In some cases, the functional split between the CU 160 and the DU 165 or between the DU 165 and the RU 170 may be within the protocol layer (e.g., some functions of the protocol layer may be performed by one of the CU 160, DU 165, or RU 170, while other functions of the protocol layer may be performed by a different one of the CU 160, DU 165, or RU 170). The CU 160 may be further functionally split into CU control plane (CU-CP) and CU user plane (CU-UP) functions. The CU 160 may be connected to one or more DUs 165 via midhaul communication links 162 (e.g., F1, F1-c, F1-u), and the DU 165 may be connected to one or more RUs 170 via fronthaul communication links 168 (e.g., an open fronthaul (FH) interface). In some examples, midhaul communication link 162 or fronthaul communication link 168 may be implemented according to an interface (e.g., a channel) between layers of a protocol stack supported by respective network entities 105 that communicate via such communication links.

[0050] In some wireless communication systems (e.g., wireless communication system 100), the infrastructure and spectrum resources used for radio access may support wireless backhaul link capabilities to supplement wired backhaul connections, thereby providing an IAB network architecture (e.g., to core network 130). In some cases, in an IAB network, one or more network entities 105 (e.g., IAB nodes 104) may be partially controlled by each other. One or more IAB nodes 104 may be referred to as a donor entity or IAB donor. One or more DUs 165 or one or more RUs 170 may be partially controlled by one or more CUs 160 associated with a donor network entity 105 (e.g., donor base station 140). One or more donor network entities 105 (e.g., IAB donors) may communicate with one or more additional network entities 105 (e.g., IAB nodes 104) via supported access and backhaul links (e.g., backhaul communication link 120). The IAB node 104 may include an IAB mobile terminal (IAB-MT) controlled (e.g., scheduled) by the DU 165 of the coupled IAB donor. The IAB-MT may include an independent set of antennas for relaying communications with the UE 115, or may share the same antennas of the IAB node 104 (e.g., of the RU 170) for access via the DU 165 of the IAB node 104 (e.g., referred to as a virtual IAB-MT (vIAB-MT)). In some examples, the IAB node 104 may include a DU 165 that supports communication links with additional entities (e.g., IAB node 104, UE 115) within a relay chain or configuration (e.g., downstream) of the access network. In such cases, one or more components of the decomposed RAN architecture (e.g., one or more IAB nodes 104 or components of the IAB node 104) may be configured to operate according to the techniques described herein.

[0051] Where the techniques described herein are applied to the context of a disaggregated RAN architecture, one or more components of the disaggregated RAN architecture may be configured to support frequency shifting in low-power devices as described herein. For example, some operations described as being performed by a UE 115 or a network entity 105 (e.g., a base station 140) may additionally or alternatively be performed by one or more components of the disaggregated RAN architecture (e.g., an IAB node 104, a DU 165, a CU 160, a RU 170, a RIC 175, a SMO 180).

[0052] UE 115 may include or may be referred to as a mobile device, a wireless device, a remote device, a handheld device, or a subscriber device, or some other suitable terminology, where "device" may also be referred to as a unit, a station, a terminal, or a client, etc. UE 115 may also include or may be referred to as a personal electronic device, such as a cellular phone, a personal digital assistant (PDA), a tablet computer, a laptop computer, or a personal computer. In some examples, UE 115 may include or may be referred to as a wireless local loop (WLL) station, an Internet of Things (IoT) device, an Internet of Everything (IoE) device, or a machine type communication (MTC) device, etc., which may be implemented in various objects, such as appliances or vehicles, meters, etc.

[0053] The UE 115 described herein may be capable of communicating with various types of devices, such as other UEs 115, which may sometimes act as relays, as well as network entities 105 and network equipment including macro eNBs or gNBs, small cell eNBs or gNBs, or relay base stations, etc. Figure 1 shown.

[0054] The UE 115 and the network entity 105 can wirelessly communicate with each other via one or more communication links 125 (e.g., access links) using resources associated with one or more carriers. The term "carrier" may refer to a set of RF spectrum resources having a physical layer structure defined for supporting the communication link 125. For example, a carrier used for the communication link 125 may include a portion of an RF spectrum band (e.g., a bandwidth part (BWP)) that operates according to one or more physical layer channels for a given radio access technology (e.g., LTE, LTE-A, LTE-A Pro, NR). Each physical layer channel may carry acquisition signaling (e.g., synchronization signals, system information), control signaling for coordinating carrier operations, user data, or other signaling. The wireless communication system 100 may support communications with the UE 115 using carrier aggregation or multi-carrier operation. Depending on the carrier aggregation configuration, the UE 115 may be configured with multiple downlink component carriers and one or more uplink component carriers. Carrier aggregation may be used for both frequency division duplex (FDD) and time division duplex (TDD) component carriers. Communication between the network entity 105 and other devices may refer to communication between those devices and any portion (e.g., entity, sub-entity) of the network entity 105. For example, the terms "send," "receive," or "communicate" when referring to the network entity 105 may refer to any portion of the network entity 105 (e.g., base station 140, CU 160, DU 165, RU 170) of the RAN communicating with another device (e.g., directly or via one or more other network entities 105).

[0055] The signal waveform transmitted via the carrier may include multiple subcarriers (e.g., using a multicarrier modulation (MCM) technique such as orthogonal frequency division multiplexing (OFDM) or discrete Fourier transform spread OFDM (DFT-S-OFDM)). In a system employing MCM techniques, a resource element (RE) may refer to a resource of one symbol period (e.g., the duration of one modulation symbol) and one subcarrier, in which case the symbol period and subcarrier spacing may be inversely related. The number of bits carried by each RE may depend on the modulation scheme (e.g., the order of the modulation scheme, the coding rate of the modulation scheme, or both), such that a relatively high number of REs (e.g., in the transmission duration) and a relatively high-order modulation scheme may correspond to a relatively high communication rate. Wireless communication resources may refer to a combination of RF spectrum resources, time resources, and spatial resources (e.g., spatial layers or beams), and the use of multiple spatial resources may increase the data rate or data integrity used for communications with UE 115.

[0056] The time interval for the network entity 105 or the UE 115 may be expressed as a multiple of a basic time unit, which may be, for example, a sampling period T s =1 / (Δf max ·N f ) seconds, where Δf max It can represent the supported subcarrier spacing, and N f The supported discrete Fourier transform (DFT) size may be indicated. Time intervals of communication resources may be organized according to radio frames, each having a specified duration (e.g., 10 milliseconds (ms)). Each radio frame may be identified by a system frame number (SFN) (e.g., ranging from 0 to 1023).

[0057] Each frame may include a plurality of consecutively numbered subframes or time slots, and each subframe or time slot may have the same duration. In some examples, a frame may be divided (e.g., in the time domain) into subframes, and each subframe may be further divided into a certain number of time slots. Alternatively, each frame may include a variable number of time slots, and the number of time slots may depend on the subcarrier spacing. Each time slot may include a certain number of symbol periods (e.g., depending on the length of the cyclic prefix appended to the front of each symbol period). In some wireless communication systems 100, the time slot may be further divided into a plurality of mini-time slots associated with one or more symbols. Excluding the cyclic prefix, each symbol period may be associated with one or more (e.g., N f The duration of a symbol period may depend on the subcarrier spacing or the operating frequency band.

[0058] A subframe, slot, mini-slot, or symbol may be the smallest scheduling unit (e.g., in the time domain) of the wireless communication system 100 and may be referred to as a Transmit Time Interval (TTI). In some examples, the TTI duration (e.g., the number of symbol periods in a TTI) may be variable. Additionally or alternatively, the smallest scheduling unit of the wireless communication system 100 may be dynamically selected (e.g., in bursts of shortened TTIs (sTTIs)).

[0059] According to various techniques, physical channels may be multiplexed using carriers for communication. Physical control channels and physical data channels may be multiplexed for signaling over downlink carriers, for example, using one or more of time division multiplexing (TDM), frequency division multiplexing (FDM), or hybrid TDM-FDM techniques. A control region (e.g., a control resource set (CORESET)) of a physical control channel may be defined by a set of symbol periods and may extend across the system bandwidth of a carrier or a subset of the system bandwidth. One or more control regions (e.g., CORESETs) may be configured for a set of UEs 115. For example, one or more of UEs 115 may monitor or search the control region for control information according to one or more search space sets, and each search space set may include one or more control channel candidates in one or more aggregation levels arranged in a cascaded manner. The aggregation level of a control channel candidate may refer to the amount of control channel resources (e.g., control channel elements (CCEs)) associated with coded information for a control information format having a given payload size. The search space sets may include a common search space set configured for transmitting control information to multiple UEs 115 and a UE-specific search space set for transmitting control information to a specific UE 115 .

[0060] In some examples, network entities 105 (e.g., base stations 140, RUs 170) can be mobile and, therefore, provide communication coverage for mobile coverage areas 110. In some examples, different coverage areas 110 associated with different technologies can overlap, but the different coverage areas 110 can be supported by the same network entity 105. In some other examples, overlapping coverage areas 110 associated with different technologies can be supported by different network entities 105. The wireless communication system 100 can include, for example, a heterogeneous network in which different types of network entities 105 provide coverage for various coverage areas 110 using the same or different radio access technologies.

[0061] The wireless communication system 100 may be configured to support ultra-reliable communication or low-latency communication or various combinations thereof. For example, the wireless communication system 100 may be configured to support ultra-reliable low-latency communication (URLLC). The UE 115 may be designed to support ultra-reliable or low-latency or critical functions. Ultra-reliable communication may include private or group communication and may be supported by one or more services such as push-to-talk, video, or data. Support for ultra-reliable, low-latency functionality may include prioritization of services, and such services may be used for public safety or general commercial applications. The terms "ultra-reliable," "low latency," and "ultra-reliable low latency" are used interchangeably herein.

[0062] In some examples, a UE 115 can be configured to support communication directly with other UEs 115 via a device-to-device (D2D) communication link 135 (e.g., according to a peer-to-peer (P2P), D2D, or sidelink protocol). In some examples, one or more UEs 115 in a group performing D2D communication can be within a coverage area 110 of a network entity 105 (e.g., a base station 140, a RU 170), which can support aspects of such D2D communication configured by the network entity 105 (e.g., scheduled by the network entity). In some examples, one or more UEs 115 in such a group can be outside the coverage area 110 of the network entity 105 or can otherwise be unable or not configured to receive transmissions from the network entity 105. In some examples, a group of UEs 115 communicating via D2D communication can support a one-to-many (1:M) system, in which each UE 115 transmits to each of the other UEs 115 in the group. In some examples, network entity 105 may facilitate scheduling of resources for D2D communications. In some other examples, D2D communications may be performed between UEs 115 without involving network entity 105.

[0063] The core network 130 may provide user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions. The core network 130 may be an evolved packet core (EPC) or a 5G core (5GC), which may include at least one control plane entity (e.g., a mobility management entity (MME), an access and mobility management function (AMF)) for managing access and mobility and at least one user plane entity (e.g., a serving gateway (S-GW), a packet data network (PDN) gateway (P-GW), or a user plane function (UPF)) for routing packets or interconnecting to external networks. The control plane entity may manage non-access stratum (NAS) functions such as mobility, authentication, and bearer management for UEs 115 served by network entities 105 (e.g., base stations 140) associated with the core network 130. User IP packets may be delivered through the user plane entity, which may provide IP address allocation and other functions. The user plane entity may be connected to the IP services 150 of one or more network operators. IP services 150 may include access to the Internet, an intranet, an IP Multimedia Subsystem (IMS), or packet-switched streaming services.

[0064] The wireless communication system 100 can operate using one or more frequency bands that can range from 300 megahertz (MHz) to 300 gigahertz (GHz). Generally speaking, the region from 300 MHz to 3 GHz is referred to as the ultra-high frequency (UHF) region or decimeter band because the wavelengths range from about one decimeter to one meter in length. UHF waves can be blocked or redirected by buildings and environmental features (which can be referred to as clusters), but these waves can penetrate structures sufficiently for a macro cell to provide service to a UE 115 located indoors. Communication using UHF waves can be associated with smaller antennas and a shorter range (e.g., less than 100 kilometers) than communication using the lower frequencies and longer waves in the high frequency (HF) or very high frequency (VHF) portions of the spectrum below 300 MHz.

[0065] The wireless communication system 100 can utilize licensed and unlicensed RF spectrum bands. For example, the wireless communication system 100 can use unlicensed bands (such as the 5 GHz Industrial, Scientific, and Medical (ISM) band) to employ license assisted access (LAA), LTE unlicensed (LTE-U) radio access technology, or NR technology. When operating using unlicensed RF spectrum bands, devices such as the network entity 105 and the UE 115 can employ carrier sensing for conflict detection and avoidance. In some examples, operations using unlicensed bands can be based on carrier aggregation configuration (e.g., LAA) in combination with component carriers operating using licensed bands. Operations using unlicensed spectrum can include downlink transmissions, uplink transmissions, P2P transmissions, or D2D transmissions, among others.

[0066] A network entity 105 (e.g., base station 140, RU 170) or UE 115 may be equipped with multiple antennas that can be used to employ techniques such as transmit diversity, receive diversity, multiple-input, multiple-output (MIMO) communications, or beamforming. The antennas of the network entity 105 or UE 115 may be located within one or more antenna arrays or antenna panels, which may support MIMO operations or transmit or receive beamforming. For example, one or more base station antennas or antenna arrays may be co-located at an antenna assembly, such as an antenna tower. In some examples, the antennas or antenna arrays associated with the network entity 105 may be located at different geographical locations. The network entity 105 may include an antenna array having a set of multiple rows and columns of antenna ports that the network entity 105 can use to support beamforming for communications with the UE 115. Similarly, the UE 115 may include one or more antenna arrays that may support various MIMO or beamforming operations. Additionally or alternatively, the antenna panels may support RF beamforming for signals transmitted via the antenna ports.

[0067] Beamforming (which may also be referred to as spatial filtering, directional transmission, or directional reception) is a signal processing technique that can be used at a transmitting device or a receiving device (e.g., a network entity 105, a UE 115) to shape or steer an antenna beam (e.g., a transmit beam, a receive beam) along a spatial path between the transmitting device and the receiving device. Beamforming can be achieved by combining signals communicated via antenna elements of an antenna array so that some signals propagating along a particular orientation relative to the antenna array experience constructive interference, while other signals experience destructive interference. Adjustments to signals communicated via antenna elements can include the transmitting device or the receiving device applying an amplitude offset, a phase offset, or both to signals carried via antenna elements associated with the device. The adjustments associated with each of these antenna elements can be defined by a set of beamforming weights associated with a particular orientation (e.g., relative to the antenna array of the transmitting device or the receiving device or relative to some other orientation).

[0068] In some cases, the UE 115 or the network entity 105 may communicate with one or more passive Internet of Things (IoT) devices (e.g., such as RFID tags of different classifications). For example, a passive IoT device may rely on passive communication techniques, such as backscatter communication. Using such techniques, low-power and low-cost devices can be implemented. Using current technology, ultra-high frequency RFID (UHF RFID) systems can be established and widely used. Such systems can also be based on backscatter communication. However, current UHF RFID systems may be incompatible with NR systems. For example, current RFID systems may operate in the ISM band, while NR systems may operate in a licensed band. Therefore, there may not be technology for handling interference between these two different systems (e.g., interference handling between the ISM band and the NR licensed band), and new designs for passive IoT in NR may be used.

[0069] Furthermore, in unlicensed bands (e.g., NR unlicensed bands (NR-U)), the PSD limit may be equivalent to 8 dBm per 3 kHz (e.g., up to 8 dBm of power per 3 kHz band). Such PSD limits may limit the total transmit power of a radio frequency source (e.g., a continuous wave source), which may result in a limited coverage area. For example, in RFID communications, an RFID reader (e.g., or an RFID source, if different from the reader) may use a single tone (e.g., a single subband or a single RB) to transmit a continuous wave (e.g., a forward link). Therefore, an RFID tag may use the power received from the single tone to transmit a backscatter link. However, in unlicensed bands, one or more regulatory agencies (e.g., such as the FCC) may implement regulations regarding PSD per 3 kHz subband. Therefore, in zero-power IoT (ZP-IoT) in NR-U, if the RFID source uses a single subcarrier (e.g., a single RB), the total transmit power of the RFID source may be limited, thereby limiting the coverage area of RFID communications in NR-U. Furthermore, PSD constraints associated with the licensed NR domain may limit the transmit power of the RFID source, thereby limiting the coverage in the licensed NR domain (e.g., licensed NR subbands).

[0070] The techniques described herein may enable a wireless device (e.g., such as UE 115 or network entity 105) to use a single subcarrier or multiple subcarriers (e.g., multiple tones, multiple RBs, multiple REs, etc.) to increase the transmit power of a continuous wave, thereby increasing the coverage area of such communications. Furthermore, the wireless device may determine the number of RBs to use for a reader-to-RFID tag communication link based on the classification of the RFID tag. That is, the wireless device may use the influence of the RFID tag type when considering the resources allocated for reader-to-RFID tag communications. Furthermore, introducing multiple subcarriers for such communications may result in interference cancellation (e.g., which may be difficult to achieve). Accordingly, the RFID tag may perform a frequency shift based on a frequency shift value so that the frequency resources of the continuous wave do not interfere with the frequency resources of the backscattered signal.

[0071] For example, a wireless device may transmit continuous waves using a different number of RBs to meet the RFID tag's target transmit and receive power while remaining within the PSD constraints. To avoid interference caused by using an increased number of RBs, the RFID tag may perform a frequency shift on the backscattered signal, such that the frequency resources used when transmitting the continuous wave differ from (e.g., do not overlap or partially overlap) the frequency resources used when transmitting the backscattered signal. In some examples, the RFID tag may send capability information to the wireless device indicating the ability to perform the frequency shift and indicating the frequency shift value. In this way, communication between the RFID tag and the wireless device may have a larger communication area while also accounting for interference.

[0072] In some other examples, in scenarios where there may not be a PSD constraint, the wireless device may be enabled to use a single subcarrier (e.g., a single tone, a single RB, or a single RE) with increased power. In this way, the wireless device may transmit a continuous wave at a power that meets the RFID tag's target transmit power, target receive power, or both.

[0073] Figure 2 An example of a wireless communication system 200 that supports frequency shifting in low-power devices according to one or more aspects of the present disclosure is illustrated. In some examples, the wireless communication system 200 can support aspects of the wireless communication system 100. For example, the wireless communication system 200 can include a wireless device 205-a and a wireless device 205-c, which can be reference Figure 2 In addition, the wireless communication system 200 may include a wireless device 205-b, which may be a reference Figure 1 Example of UE 115.

[0074] In some examples, wireless device 205-b can be an example of an RFID tag that can communicate with wireless device 205-a, wireless device 205-c, or both via continuous wave 245 (e.g., forward link) and backscatter signal 255 (e.g., reverse link). Thus, wireless device 205-b can be one or more types of RFID tags. A system that supports communication between wireless device 205-a, wireless device 205-b, and wireless device 205-c can be referred to as an RFID system and can operate in the ISM band, the NR licensed band, or the NR-U band.

[0075] In some examples, wireless device 205-b can be a passive tag, which can be a lightweight IoT device without a battery. Therefore, the passive tag can capture power from radio waves (e.g., such as continuous wave 245) and use radio frequency backscatter communication to communicate with wireless device 205-a. For example, wireless device 205-b can include a modulated retroreflector (MRR) 215, which can allow wireless device 205-b to reflect and modulate the received light beam 210 (e.g., with high bandwidth). MRR 215 can include a modulator 225 and a reflector 220. There can be many different types of modulators 225, such as deformable microelectromechanical systems (MEMs), liquid crystals, electro-optic phase modulators, and multiple quantum wells (MQWs). In addition, there can be many different types of reflectors 220, such as corner cubes or cat's eyes. Wireless device 205-b may receive light beam 210 from wireless device 205-a and redirect light beam 210 using reflector 220 (e.g., reflect the light beam in the same or similar direction as received light beam 210). The reflected light beam 210 (e.g., light beam 210-a) may pass through modulator 225, and the modulated light beam 210 (e.g., modulated light beam 210-b) may continue in the direction specified by reflector 220. In such an example, modulated light beam 210 may be an example of backscattered signal 255.

[0076] In some examples, wireless device 205-b can be a semi-passive tag, which can be a lightweight IoT device that uses radio frequency backscatter communication to communicate with wireless device 205-a. In some cases, the semi-passive tag can include a rechargeable battery. Additionally or alternatively, the semi-passive tag can perform energy harvesting (e.g., harvesting energy from received wireless transmissions, harvesting energy from wind power, harvesting energy from solar power, etc.) and store the harvested energy in an energy storage circuit. Additionally or alternatively, the semi-passive tag can include a power amplifier, which can be embedded in the receiving component of the tag or the transmitting component of the tag.

[0077] In some examples, wireless device 205-b can be a semi-active tag, which can be a lightweight IoT device that uses radio frequency backscatter communication to communicate with wireless device 205-a. Additionally or alternatively, a semi-active tag can perform active communication. For example, wireless device 205-b can receive wireless transmissions at antenna 230 and transmit responses to the wireless transmissions using antenna 230. Thus, a semi-active tag can include a battery that can be rechargeable or can perform energy harvesting and store the harvested energy in an energy storage circuit.

[0078] In some examples, wireless device 205-b may be an active tag, which may be a lightweight IoT device that uses active communication to communicate with wireless device 205-a. Thus, the active tag may include a battery that may be rechargeable or may perform energy harvesting and store the harvested energy in an energy storage circuit.

[0079] like Figure 2 As illustrated, wireless device 205-b may include an oscillator 235 that may be used to generate transmissions (e.g., backscatter or active transmissions) from wireless device 205-b to wireless device 205-a. For example, oscillator 235 may be tuned so as to generate transmissions within a given frequency range. In some examples, wireless device 205-b may include a frequency-locked loop (FLL) 240. FLL 240 may be a circuit that compares the frequency of oscillator 235 to a reference frequency and may automatically increase or decrease the frequency of oscillator 235 until the frequency of oscillator 235 matches the frequency of the reference frequency.

[0080] In some cases, wireless device 205-a may communicate with wireless device 205-b via a single RB (e.g., a single subband). For example, wireless device 205-a may transmit a continuous wave 245-a (e.g., a forward link signal) to wireless device 205-b using a single RB. Based on receiving the continuous wave 245-a, wireless device 205-b may use (e.g., in the case of a passive or semi-passive RFID tag) or collect (e.g., in the case of a semi-active or active RFID tag) energy from the continuous wave 245-a to modulate the continuous wave 245-a with data and transmit a backscatter signal 255 (e.g., a modulated continuous wave 245-a) to wireless device 205-a via the single RB. That is, wireless device 205-a may continuously transmit the continuous wave 245-a so that wireless device 205-b may use or collect power associated with the continuous wave 245-a to transmit the backscatter signal 255. However, PSD constraints associated with a single RB (eg, a single subband or RE) may limit the transmit power of the continuous wave 245-a, thereby limiting the communication coverage area between the wireless device 205-a and the wireless device 205-b and resulting in less efficient communication.

[0081] As described herein, the wireless device 205-a may transmit the continuous wave 245-a using different numbers of RBs (e.g., multiple subcarriers) (e.g., for use in a forward link from a reader to an RFID tag). That is, the wireless device 205-a may transmit the continuous wave 245-a using different numbers of RBs in order to meet the target transmit and receive power of the wireless device 205-b while complying with a PSD constraint per RB (e.g., a PSD constraint per subcarrier). That is, the wireless device 205-a may transmit the continuous wave 245-a using a certain number of RBs, where the certain number of RBs is configured to meet the transmit or receive power constraint of the wireless device 205-b. Alternatively, in scenarios where there may not be a PSD limit for a single RB, the wireless device 205-a may be enabled to use a single subcarrier (e.g., a single tone, a single RB, or a single RE) with increased power (e.g., an increased power that exceeds the PSD limit). In this manner, the wireless device 205 - a may transmit the continuous wave 245 - a at a power that meets the target transmit power, target receive power, or both, of the wireless device 205 - b .

[0082] In some examples, wireless device 205-a may transmit continuous wave 245-a using different numbers of RBs based on the classification type (e.g., tag type) of wireless device 205-b. For example, different types of RFID tags (e.g., the classification of wireless device 205-b) may have different receive sensitivities (e.g., the receive power required to activate and use the RFID tag). Therefore, wireless device 205-a (e.g., the RF source of wireless device 205-b) may transmit continuous wave 245-a at different transmit powers to meet the power constraints of the different types of classification of wireless device 205-b. In this way, the target transmit power and target receive power may be configured according to the classification type of wireless device 205-b.

[0083] As an illustrative example, if wireless device 205-b is classified as a passive RFID tag, wireless device 205-a may transmit continuous wave 245-a using a first number of RBs to meet a target received power of -20 dBm. In another example, if wireless device 205-b is classified as a semi-passive RFID tag, wireless device 205-a may transmit continuous wave 245-a using a second number of RBs to meet a target received power of -35 dBm. Furthermore, if wireless device 205-b is classified as a semi-passive tag with a power amplifier, wireless device 205-a may transmit continuous wave 245-a using a third number of RBs to meet a target received power of -55 dBm. Therefore, if the distance between wireless device 205-a and wireless device 205-b is the same, wireless device 205-a may control the transmit power of continuous wave 245-a by allocating (e.g., controlling) a different number of RBs based on the classification of wireless device 205-b, thereby achieving power savings at wireless device 205-a.

[0084] In some examples, to meet the target power associated with each classification type, the wireless device 205-a can be configured with a table or formula (e.g., passive RFID tag = x power or x RBs, semi-passive tag = y RBs or y power) so that the wireless device 205-a can look up or calculate the transmit power. For example, the wireless device 205-a can be pre-configured with a table indicating the power, number of RBs, or both associated with each classification type (e.g., passive, semi-passive, semi-active, active). Additionally or alternatively, the wireless device 205-a can use one or more formulas to calculate the target power, number of RBs, or both based on the classification of the wireless device 205-b.

[0085] In some examples, wireless device 205-c (e.g., a network entity or a sidelink UE) may transmit control signaling 260 instructing wireless device 205-a (e.g., a UE) to communicate with wireless device 205-b. Thus, if wireless device 205-c indicates to wireless device 205-a that it intends to communicate with wireless device 205-b, wireless device 205-c may dynamically indicate to wireless device 205-a via control signaling 260 the target transmit and receive power, the number of RBs, the classification type of wireless device 205-b, the number of RBs per classification type, or a combination thereof. Furthermore, wireless device 205-c may configure wireless device 205-a with a table (e.g., a table indicating target transmit power, number of RBs, or both per classification type). In such cases, wireless device 205-a may dynamically determine the transmit power (e.g., number of RBs) of continuous wave 245-a based on the configured table. Alternatively, wireless device 205-a may be preconfigured with a transmit power per RFID tag classification.

[0086] Based on the determined number of RBs (e.g., transmit power), wireless device 205-a may transmit continuous wave 245-a using a first set of frequency resources including the determined number of RBs. Wireless device 205-b may receive continuous wave 245-a, modulate continuous wave 245-a with data to generate backscatter signal 255, and transmit backscatter signal 255 to wireless device 205-a using energy or power obtained or collected (e.g., via energy harvesting) from continuous wave 245-a. In other words, the wireless device may transmit backscatter signal 255 via the first set of resources using the number of RBs used for continuous wave 245-a.

[0087] However, if wireless device 205-b uses the same RB (e.g., the same subcarrier) as continuous wave 245-a for backscatter signal 255, then at wireless device 205-a, backscatter signal 255 may interfere with (e.g., overwhelm) continuous wave 245-a. That is, to enable wireless device 205-b to transmit backscatter signal 255, wireless device 205-a may continuously transmit continuous wave 245-a (e.g., an unmodulated wave in a forward link) to provide a carrier for backscatter signal 255 (e.g., a backscatter link). However, if backscatter signal 255 is transmitted using the same RB as continuous wave 245-a, wireless device 205-a may experience interference, which may result in wireless device 205-a not successfully receiving backscatter signal 255.

[0088] As described herein, the wireless device 205-b can be configured to perform frequency shifting to achieve a certain frequency division multiplexing (FDM) of the backscatter signal 255 and the continuous wave 245-a. Thus, the wireless device 205-a can filter out the RBs associated with the continuous wave 245-a (e.g., the unmodulated reference signal tones) and receive the backscatter signal 255. That is, the wireless device 205-b can receive the continuous wave 245-a via a first set of frequency resources (e.g., including a number of RBs determined to meet the target transmit and receive power) and transmit the backscatter signal 255 via a second set of frequency resources that is offset relative to the first set of frequency resources (e.g., including the same number of RBs as the first set of frequency resources).

[0089] For example, to avoid frequency overlap (e.g., overlap between RBs used for continuous wave 245-a and backscatter signal 255), wireless device 205-b may perform frequency shifting on the RBs used for the backscatter signal. Wireless device 205-b may shift the backscatter signal in frequency relative to continuous wave 245-a based on a frequency shift value. This frequency shift value may be provided in units of RBs, REs, or frequency units. Furthermore, the ability to perform frequency shifting may be associated with the classification type of wireless device 205-b. As an illustrative example, if wireless device 205-b is classified as passive, wireless device 205-b may not perform frequency shifting (e.g., may not have the ability to perform frequency shifting). In another example, if wireless device 205-b is classified as semi-passive, wireless device 205-a may perform frequency shifting (e.g., may have the ability to perform frequency shifting).

[0090] In some examples, a frequency shift value may be preconfigured at wireless device 205-a based on the classification of wireless device 205-b. That is, wireless device 205-a may be preconfigured with one or more tables indicating frequency shift capabilities and frequency shift values associated with each classification type. In some other examples, wireless device 205-b may send a capability message 250-a to wireless device 205-a, where capability message 250-a may indicate the ability of wireless device 205-b to perform frequency shifting, the classification of wireless device 205-b, the frequency shift value, or a combination thereof. In some examples, wireless device 205-a (e.g., acting as both a radio frequency source and a reader in full-duplex mode) may dynamically configure the frequency shift value of wireless device 205-b. That is, wireless device 205-a may send a frequency shift message 265-a indicating the frequency shift value to wireless device 205-b.

[0091] In some examples, wireless device 205-c may be a radio frequency source (e.g., a transmitter of continuous wave 245-b), while wireless device 205-a may be a reader (e.g., a receiver of backscatter signal 255). In such examples, wireless device 205-c may dynamically configure a frequency shift value to wireless device 205-b. That is, wireless device 205-c may send a frequency shift message 265-b indicating the frequency shift value to wireless device 205-b. Thus, wireless device 205-c may send a capability message 250-b to wireless device 205-a, the capability message indicating the ability of wireless device 205-b to perform frequency shifting, the classification of wireless device 205-b, the frequency shift value, or a combination thereof.

[0092] In some examples, wireless device 205-c may indicate to wireless device 205-a that it is communicating with wireless device 205-b. In such examples, wireless device 205-c may send a capability message 250-b indicating a frequency shift value to be used in communicating with wireless device 205-b. Furthermore, capability message 250-b may include an allocation of RBs for transmitting continuous wave 245-b and an allocation of RBs to be used after wireless device 205-b performs backscatter (e.g., an offset RB for transmitting backscatter signal 255).

[0093] That is, wireless device 205-c (e.g., a radio frequency source) may signal continuous wave 245-b (e.g., an unmodulated continuous waveform) to wireless device 205-a (e.g., a reader). Accordingly, wireless device 205-a may use the information received in capability message 250-b and the signaled allocation of continuous wave 245-b to determine allocation of backscatter signals. For example, wireless device 205-a may use the classification of wireless device 205-b (e.g., a given RFID tag class), the ability of wireless device 205-b to perform frequency shifting, a frequency shift value (e.g., a frequency shift configuration), or a combination thereof to determine allocation of backscatter signals 255. Wireless device 205-c may transmit continuous wave 245-b to wireless device 205-b via a first set of frequency resources, wherein wireless device 205-b may use or collect power from continuous wave 245-b to modulate continuous wave 245-b with data, generate backscatter signal 255, and transmit backscatter signal 255 according to the frequency shift value. Wireless device 205-a may monitor the number of RBs used for backscatter signals based on the information indicated in capability message 250-b. That is, wireless device 205-a may monitor a second set of frequency resources that has been shifted relative to the first set of frequency resources by the frequency shift value. Based on the monitoring, wireless device 205-a may receive backscatter signals 255 via the second set of frequency resources.

[0094] In some examples, wireless device 205-a (e.g., a reader) can estimate the channel between wireless device 205-a and wireless device 205-b using continuous wave 245 (e.g., a signaled unmodulated forward link signal). In such examples, wireless device 205-a can perform time and frequency correction based on the channel estimate in order to decode backscatter signal 255.

[0095] Figure 3 An example of a resource allocation diagram 300 for supporting frequency shifting in low power devices according to one or more aspects of the present disclosure is illustrated. The resource allocation diagram 300 may implement or be implemented by aspects of the wireless communication system 100 and the wireless communication system 200. For example, the resource allocation diagram may be implemented by a method as described herein. Figure 1 and Figure 2 The described UE 115, RFID tag, and network entity 105 implement the resource allocation map 300. The resource allocation map 300 may include frequency resources 305 and frequency resources 310, which may be as described herein. Figure 2 Examples of the described first and second frequency resource sets. As described herein, the term RB may refer to any of a frequency tone, a subcarrier, a subband, a RE, a frequency unit, etc.

[0096] In some examples, frequency resources 305 may be used for communication between an RFID source, an RFID reader, and an RFID tag (e.g., the RFID source and the RFID reader may be the same device or different devices). For example, frequency resources 305 may include one or more RBs 315 allocated for transmitting a continuous wave (e.g., such as the continuous wave 245 described herein). That is, the RFID source may use a different number of RBs 315 in order to transmit the continuous wave and meet the target transmit and receive power of the RFID tag. The RFID source may use a different number of RBs 315 according to the embodiments described herein. Figure 2 The described techniques determine the number of RBs 315. Additionally, the frequency resources may include one or more blank RBs 320. Such blank RBs 320 may be allocated for use by other devices in the wireless communication system.

[0097] The RFID tag may receive the continuous wave and use or harvest power from the continuous wave to modulate the continuous wave with data and generate a backscatter signal (e.g., such as backscatter signal 255 as described herein). According to the techniques described herein, the RFID tag may shift resource 310 in frequency relative to frequency resource 305 by frequency shift value 325 to avoid frequency overlap between reflected RB 330 (which may refer to an RB for backscatter signals and, in some cases, may be referred to as a backscatter RB) and RB 315 (for the continuous wave).

[0098] In some examples, the size of frequency shift value 325 can be based on the structure of RBs 315 in resource 305. For example, if RBs 315 used for continuous waves (e.g., forward link subcarriers) are continuous in frequency resource 305, frequency shift value 325 can be at least greater than the number of RBs 315 used for continuous waves (e.g., unmodulated signals used by the RF source). Thus, if the RFID reader is different from the RFID source, the RFID reader can receive an indication of the allocated RBs 315 for continuous waves and frequency shift value 325 in order to determine the frequency allocation of backscattered signals in frequency resource 310. If the RFID reader and the RFID source are the same device, the RFID reader can monitor reflected RBs 330 based on the frequency shift value 325 known at the RFID reader.

[0099] For example, an RFID source may continuously allocate and transmit RBs 315 in frequency resource 305. Therefore, the RFID tag may shift the reflected RBs 330 by a frequency shift value 325 that is greater than the number of RBs 315. As illustrated in resource allocation diagram 300, the RFID source may allocate four consecutive RBs 315 in frequency resource 305 for transmitting a continuous wave. Therefore, the frequency shift value 325 at the RFID tag may be at least greater than four. As illustrated in the figure, the frequency shift value 325 may be seven. In this way, the RFID tag can transmit a backscattered signal via the reflected RBs 330 that have been shifted in frequency relative to the RBs 315 used to transmit the continuous wave, thereby avoiding interference between the two signals.

[0100] Figure 4 An example of a resource allocation diagram 400 for supporting frequency shifting in low-power devices according to one or more aspects of the present disclosure is illustrated. Aspects of the resource allocation diagram 400 may implement or be implemented by aspects of the wireless communication system 100, the wireless communication system 200, and the resource allocation diagram 300 as described herein. For example, the resource allocation diagram may be implemented by the UE 115, the network entity 105, and the RFID tag. In addition, the resource allocation diagram 400 may include frequency resources 405 and frequency resources 410, which may be as described herein with reference to Figure 2 and Figure 3 Examples of the described first set of frequency resources and the second set of frequency resources.

[0101] In some examples, frequency resources 405 may be used for communication between an RFID source, an RFID reader, and an RFID tag (e.g., the RFID source and the RFID reader may be the same device or different devices). For example, frequency resources 405 may include one or more RBs 415 allocated for transmitting a continuous wave (e.g., such as the continuous wave 245 described herein). That is, the RFID source may use a different number of RBs 415 in order to transmit the continuous wave and meet the target transmit and receive power of the RFID tag. The RFID source may use a different number of RBs 415 according to the embodiments described herein. Figure 2 A technique is described to determine the number of RB 415.

[0102] The RFID tag can receive the continuous wave and use or harvest power from the continuous wave to modulate the continuous wave with data and generate a backscatter signal (e.g., such as backscatter signal 255 as described herein). According to the techniques described herein, the RFID tag can shift resource 410 in frequency relative to frequency resource 405 by a frequency shift value 420 to avoid frequency overlap between reflected RB 425 (for the backscatter signal) and RB 415 (for the continuous wave).

[0103] In some examples, the size of the frequency shift value 420 can be based on the structure of the RBs 415 in the resource 405. For example, the RBs 415 can be allocated in a comb-like structure in the frequency resource 405. That is, if the RBs 415 in the frequency resource 405 are discretely allocated and transmitted at intervals or comb-tooth levels (e.g., similar to a sounding reference signal), the frequency shift value 420 can be smaller than the intervals in the frequency resource 405. In general, the granularity of the frequency shift value 420 can be given based on RBs.

[0104] For example, RBs 415 may be allocated in a comb-like structure within resource 405. Therefore, the frequency shift value 420 used by the RFID tag may be smaller than the spacing between RBs 415. As an illustrative example, the RFID source may allocate RBs 415 in increments of five RBs. Therefore, the frequency shift value 420 may be configured to be smaller than five. As illustrated, the frequency shift value 420 used in frequency resource 410 may be equal to one. In this manner, the RFID tag may transmit a backscattered signal via a reflected RB 425 that has been shifted in frequency relative to RB 415 used to transmit the continuous wave, thereby avoiding interference between the two signals.

[0105] Figure 5An example of a process flow 500 for supporting frequency shifting in low-power devices according to one or more aspects of the present disclosure is illustrated. Aspects of the process flow 500 may implement or be implemented by aspects of the wireless communication system 100, the wireless communication system 200, the resource allocation map 300, and the resource allocation map 400. For example, the process flow 500 may include a wireless device 505-a, which may be an example of a wireless device 205-a, a UE 115, or a network entity 105 that can operate as both an RFID source and an RFID reader as described herein. Additionally, the process flow 500 may include a wireless device 505-b, which may be an example of a wireless device 205-b or an RFID tag. The process flow 500 may also include a wireless device 505-c, which may be an example of a wireless device 205-c operating as an RFID source.

[0106] In the following description of process flow 500, operations may be performed in an order different from that shown. Certain operations may also be excluded from process flow 500, or other operations may be added to process flow 500. In addition, although some operations or signaling are shown as occurring at different times for discussion purposes, these operations may actually occur simultaneously.

[0107] The process flow 500 may illustrate one or more operations that support the use of various numbers of RBs in order to meet the target transmit and receive power of a low-power device. In addition, the process flow 500 may illustrate operations that implement frequency shifting in a low-power device. In some other examples, the process flow may illustrate one or more operations that support the use of a single subcarrier (e.g., a single tone, a single RB, or a single RE) with increased power in scenarios where PSD limitations may not exist in a wireless communication system. In this way, when a single RB is used to transmit a continuous wave, the target transmit power, target receive power, or both of the low-power device can be met.

[0108] At 510, wireless device 505-c may send control signaling (e.g., such as a control message) to wireless device 505-a, the control signaling including an indication that wireless device 505-b is to communicate. The control signaling may include a first set of frequency resources for transmitting a continuous wave, a number of RBs to be used in the first set of frequency resources for transmitting a continuous wave, a target transmit power for wireless device 505-b, a target receive power, a classification of wireless device 505-b (e.g., a tag type), or a combination thereof. In some examples, wireless device 505-c may include in the control signaling a frequency shift value for a second set of resources to be used by wireless device 505-b to transmit a backscatter signal.

[0109] At 515-a, wireless device 505-c may optionally send a message including the capability of wireless device 505-b to perform frequency shifting. In some examples, wireless device 505-c may include a frequency shift value in the capability message. At 515-b, wireless device 505-b may optionally send a message including the capability of wireless device 505-b to perform frequency shifting. Wireless device 505-b may include a frequency shift value to be used in the capability message.

[0110] At 520, wireless device 505-b may receive a continuous wave via the first set of frequency resources according to the set of transmission parameters. In such examples, the continuous wave may include a continuous waveform for activating wireless device 505-b. That is, the continuous wave may be continuously received for wireless device 505-b to generate a backscatter signal. In some examples, at 520-a, a continuous wave may be transmitted from wireless device 505-a (e.g., wireless device 505-a is both an RFID source and an RFID reader). Alternatively, at 520-b, a continuous wave may be transmitted from wireless device 505-c (e.g., wireless device 505-c is an RFID source and wireless device 505-a is an RFID reader).

[0111] In some examples, the number of RBs used in the first set of frequency resources may be based on a set of transmission parameters, where the transmission parameters include a target transmit power, a target receive power, a PSD constraint, or a combination thereof. In some other examples, the number of RBs used in the first set of frequency resources may be based on a classification of the wireless device 505-b. The classification of the wireless device 505-b may be one of a passive classification, a semi-passive classification, a semi-active classification, or an active classification. Furthermore, the RBs of the first set of frequency resources may be transmitted continuously (e.g., continuously in the frequency domain) or non-continuously (e.g., discretely in the frequency domain).

[0112] At 525, the wireless device 505-b may modulate the continuous wave with data based on receiving the continuous waveform that activates the wireless device 505-b. The wireless device 505-b may transmit a backscatter signal of the continuous wave via a second set of frequency resources. That is, the wireless device 505-b may use or collect energy from the continuous waveform to modulate the continuous wave with data and transmit the backscatter signal (e.g., the continuous wave modulated with data) via the second set of resources. In such an example, the second set of resources may be offset in frequency relative to the first set of frequency resources according to a frequency shift value.

[0113] For example, the wireless device 505-b may use a frequency shift value based on the structure of the first frequency resource set. That is, if the wireless device 505-b receives the RBs of the first frequency resource set continuously (e.g., in the frequency domain), the wireless device 505-b may use a frequency shift value that is at least greater than the number of RBs in the first frequency resource set. Alternatively, if the wireless device 505-b receives the RBs of the first frequency resource set in a non-contiguous manner, the wireless device 505-b may use a frequency shift value that is less than the interval between the RBs of the first frequency resource set.

[0114] At 530 , the wireless device 505 - a may receive a continuous wave backscatter signal from the wireless device 505 - b via a second set of frequency resources, wherein the second set of frequency resources is offset in frequency relative to the first set of frequency resources.

[0115] At 535, wireless device 505-a may optionally perform channel estimation on a channel between wireless device 505-a and wireless device 505-b based on the continuous wave. In such an example, wireless device 505-a may perform time and frequency correction to decode the backscattered signal based on performing the channel estimation.

[0116] Figure 6 A block diagram 600 illustrates a device 605 that supports frequency shifting in low-power devices according to one or more aspects of the present disclosure. The device 605 can be an example of aspects of the UE 115 as described herein. The device 605 can include a receiver 610, a transmitter 615, and a communication manager 620. The device 605 can also include a processor. Each of these components can communicate with each other (e.g., via one or more buses).

[0117] Receiver 610 may provide means for receiving information (such as packets, user data, control information, or any combination thereof) associated with various information channels (e.g., control channels, data channels, information channels related to frequency shifts in low-power devices). The information may be passed to other components of device 605. Receiver 610 may utilize a single antenna or a collection of multiple antennas.

[0118] The transmitter 615 may provide means for transmitting signals generated by other components of the device 605. For example, the transmitter 615 may transmit information (such as packets, user data, control information, or any combination thereof) associated with various information channels (e.g., control channels, data channels, information channels related to frequency shifts in low-power devices). In some examples, the transmitter 615 may be co-located with the receiver 610 in a transceiver module. The transmitter 615 may utilize a single antenna or a collection of multiple antennas.

[0119] The communication manager 620, the receiver 610, the transmitter 615, or various combinations thereof, or various components thereof, may be examples of means for performing various aspects of frequency shifting in a low-power device as described herein. For example, the communication manager 620, the receiver 610, the transmitter 615, or various combinations thereof, or components thereof, may support methods for performing one or more of the functions described herein.

[0120] In some examples, the communication manager 620, the receiver 610, the transmitter 615, or various combinations or components thereof may be implemented in hardware (e.g., in a communication management circuit). The hardware may include a processor, a digital signal processor (DSP), a central processing unit (CPU), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, a microcontroller, discrete gate or transistor logic components, discrete hardware components, or any combination thereof that is configured as or otherwise supports components for performing the functions described in this disclosure. In some examples, the processor and a memory coupled to the processor may be configured to perform one or more of the functions described herein (e.g., by executing instructions stored in the memory by the processor).

[0121] Additionally or alternatively, in some examples, the communication manager 620, receiver 610, transmitter 615, or various combinations or components thereof may be implemented in code executed by a processor (e.g., as communication management software or firmware). If implemented in code executed by a processor, the functionality of the communication manager 620, receiver 610, transmitter 615, or various combinations or components thereof may be performed by a general-purpose processor (e.g., configured as or otherwise supporting means for performing the functions described in this disclosure), a DSP, a CPU, an ASIC, an FPGA, a microcontroller, or any combination of these or other programmable logic devices.

[0122] In some examples, communication manager 620 can be configured to perform various operations (e.g., receive, obtain, monitor, output, transmit) using or otherwise cooperating with receiver 610, transmitter 615, or both. For example, communication manager 620 can receive information from receiver 610, transmit information to transmitter 615, or be integrated with receiver 610, transmitter 615, or both to obtain information, output information, or perform various other operations as described herein.

[0123] The communication manager 620 may support wireless communications at a first wireless device according to examples as disclosed herein. For example, the communication manager 620 may be configured to or otherwise support means for transmitting a continuous wave to a second wireless device via a first set of frequency resources and in accordance with a set of transmission parameters, wherein the continuous wave comprises a continuous waveform for activating the second wireless device. The communication manager 620 may be configured to or otherwise support means for receiving a backscatter signal of the continuous wave from the second wireless device via a second set of frequency resources, wherein the second set of frequency resources is offset in frequency relative to the first set of frequency resources.

[0124] Additionally or alternatively, the communication manager 620 may support wireless communications at a second wireless device according to examples as disclosed herein. For example, the communication manager 620 may be configured to or otherwise support means for receiving a continuous wave via a first set of frequency resources and in accordance with a set of transmit parameters, wherein the continuous wave comprises a continuous waveform for activating the second wireless device. The communication manager 620 may be configured to or otherwise support means for modulating the continuous wave with data based on the continuous waveform for activating the second wireless device. The communication manager 620 may be configured to or otherwise support means for transmitting a backscatter signal of the continuous wave via a second set of frequency resources based on modulating the continuous wave with data, wherein the second set of frequency resources is offset in frequency relative to the first set of frequency resources.

[0125] By including or configuring a communication manager 620 according to examples as described herein, the device 605 (e.g., a processor controlling the receiver 610, the transmitter 615, the communication manager 620, or a combination thereof or otherwise coupled thereto) may support techniques for receiving backscattered signals via RBs that have been shifted in frequency that may result in more efficient utilization of communication resources.

[0126] Figure 7 A block diagram 700 illustrates a device 705 that supports frequency shifting in a low-power device according to one or more aspects of the present disclosure. The device 705 can be an example of aspects of the device 605 or UE 115 as described herein. The device 705 can include a receiver 710, a transmitter 715, and a communication manager 720. The device 705 can also include a processor. Each of these components can communicate with each other (e.g., via one or more buses).

[0127] Receiver 710 may provide means for receiving information (such as packets, user data, control information, or any combination thereof) associated with various information channels (e.g., control channels, data channels, information channels related to frequency shifts in low-power devices). The information may be passed to other components of device 705. Receiver 710 may utilize a single antenna or a collection of multiple antennas.

[0128] The transmitter 715 may provide means for transmitting signals generated by other components of the device 705. For example, the transmitter 715 may transmit information (such as packets, user data, control information, or any combination thereof) associated with various information channels (e.g., control channels, data channels, information channels related to frequency shifts in low-power devices). In some examples, the transmitter 715 may be co-located with the receiver 710 in a transceiver module. The transmitter 715 may utilize a single antenna or a collection of multiple antennas.

[0129] Device 705 or its various components may be examples of components for performing various aspects of frequency shifting in low-power devices as described herein. For example, communication manager 720 may include continuous wave component 725, backscatter signal component 730, modulation component 735, or any combination thereof. Communication manager 720 may be an example of aspects of communication manager 620 as described herein. In some examples, communication manager 720 or its various components may be configured to perform various operations (e.g., receive, obtain, monitor, output, transmit) using or otherwise coordinating with receiver 710, transmitter 715, or both. For example, communication manager 720 may receive information from receiver 710, transmit information to transmitter 715, or be integrated with receiver 710, transmitter 715, or both to obtain information, output information, or perform various other operations as described herein.

[0130] The communication manager 720 can support wireless communications at a first wireless device according to examples as disclosed herein. The continuous wave component 725 can be configured to or otherwise support means for transmitting a continuous wave to a second wireless device via a first set of frequency resources and in accordance with a set of transmission parameters, wherein the continuous wave comprises a continuous waveform for activating the second wireless device. The backscatter signal component 730 can be configured to or otherwise support means for receiving a backscatter signal of the continuous wave from the second wireless device and via a second set of frequency resources, wherein the second set of frequency resources is offset in frequency relative to the first set of frequency resources.

[0131] Additionally or alternatively, the communication manager 720 can support wireless communications at the second wireless device according to examples as disclosed herein. The continuous wave component 725 can be configured to or otherwise support means for receiving a continuous wave via a first set of frequency resources and in accordance with a set of transmit parameters, wherein the continuous wave comprises a continuous waveform for activating the second wireless device. The modulation component 735 can be configured to or otherwise support means for modulating the continuous wave with data based on the continuous waveform for activating the second wireless device. The backscatter signal component 730 can be configured to or otherwise support means for transmitting a backscatter signal of the continuous wave based on modulating the continuous wave with data via a second set of frequency resources, wherein the second set of frequency resources is offset in frequency relative to the first set of frequency resources.

[0132] Figure 8 A block diagram 800 illustrates a communication manager 820 that supports frequency shifting in a low-power device in accordance with one or more aspects of the present disclosure. The communication manager 820 can be an example of aspects of the communication manager 620, the communication manager 720, or both, as described herein. The communication manager 820 or its various components can be examples of components for performing various aspects of frequency shifting in a low-power device as described herein. For example, the communication manager 820 can include a continuous wave component 825, a backscatter signal component 830, a modulation component 835, a receiving component 840, a capability component 845, a frequency shift component 850, a transmitting component 855, a channel estimation component 860, a time and frequency correction component 865, or any combination thereof. Each of these components can communicate directly or indirectly with each other (e.g., via one or more buses).

[0133] The communication manager 820 can support wireless communications at a first wireless device according to examples as disclosed herein. The continuous wave component 825 can be configured to or otherwise support means for transmitting a continuous wave to a second wireless device via a first set of frequency resources and in accordance with a set of transmission parameters, wherein the continuous wave comprises a continuous waveform for activating the second wireless device. The backscatter signal component 830 can be configured to or otherwise support means for receiving a backscatter signal of the continuous wave from the second wireless device and via a second set of frequency resources, wherein the second set of frequency resources is offset in frequency relative to the first set of frequency resources.

[0134] In some examples, receiving component 840 may be configured to or otherwise support components for receiving a message from a network entity, the message including an indication to communicate with a second wireless device, a number of RBs to use in the first set of frequency resources, a target transmit power, a target receive power, a classification of the second wireless device, or a combination thereof, wherein transmitting the continuous wave via the first set of frequency resources is based on the message.

[0135] In some examples, capability component 845 may be configured to or otherwise support components for receiving a message including an ability of the second wireless device to perform a frequency shift, wherein receiving a backscatter signal via a second set of frequency resources that is shifted in frequency relative to the first set of frequency resources is based on the message.

[0136] In some examples, the frequency shift component 850 may be configured as or otherwise support components for receiving a message indicating a frequency shift value for a second set of frequency resources, where the second set of frequency resources is offset in frequency relative to the first set of frequency resources based on the frequency shift value.

[0137] In some examples, transmitting component 855 may be configured as or otherwise support means for transmitting an indication of the first set of frequency resources for the continuous wave, the frequency shift value, or both to the third wireless device.

[0138] In some examples, channel estimation component 860 can be configured or otherwise support means for performing channel estimation on a channel between a first wireless device and a second wireless device based on a continuous wave. In some examples, time and frequency correction component 865 can be configured or otherwise support means for performing time and frequency correction to decode the backscattered signal based on performing the channel estimation.

[0139] In some examples, the first set of frequency resources is continuous in frequency. In some examples, the second set of frequency resources is offset in frequency relative to the first set of frequency resources by a frequency shift value that is greater than the number of RBs in the first set of frequency resources.

[0140] In some examples, the first set of frequency resources is non-contiguous in frequency. In some examples, the second set of frequency resources is offset in frequency relative to the first set of frequency resources by a frequency shift value that is smaller than the interval between RBs of the first set of frequency resources.

[0141] In some examples, the number of RBs in the first frequency resource set is based on a set of transmission parameters. In some examples, the set of transmission parameters includes a target transmit power, a target receive power, a PSD constraint, or a combination thereof.

[0142] In some examples, the number of RBs in the first set of frequency resources is based on a classification of the second wireless device.

[0143] In some examples, the classification of the second wireless device includes one of passive classification, semi-passive classification, semi-active classification, or active classification.

[0144] In some examples, the second set of frequency resources is offset in frequency relative to the first set of frequency resources based on a frequency shift value. In some examples, the frequency shift value is preconfigured at the first wireless device.

[0145] Additionally or alternatively, the communication manager 820 can support wireless communications at the second wireless device according to examples as disclosed herein. In some examples, the continuous wave component 825 can be configured to or otherwise support means for receiving a continuous wave via a first set of frequency resources and in accordance with a set of transmit parameters, wherein the continuous wave comprises a continuous waveform for activating the second wireless device. The modulation component 835 can be configured to or otherwise support means for modulating the continuous wave with data based on the continuous waveform for activating the second wireless device. In some examples, the backscatter signal component 830 can be configured to or otherwise support means for transmitting a backscatter signal of the continuous wave based on modulating the continuous wave with data via a second set of frequency resources, wherein the second set of frequency resources is offset in frequency relative to the first set of frequency resources.

[0146] In some examples, capability component 845 may be configured as or otherwise support components for transmitting a message indicating an ability to perform a frequency shift, wherein transmitting a backscatter signal via a second set of frequency resources that is offset in frequency relative to a first set of frequency resources is based on the ability to perform the frequency shift.

[0147] In some examples, a continuous wave is received from a first wireless device and a backscattered signal is transmitted to a third wireless device.

[0148] In some examples, the second set of frequency resources is offset in frequency relative to the first set of frequency resources based on a frequency shift value.

[0149] In some examples, the number of RBs in the first frequency resource set is based on a set of transmission parameters. In some examples, the set of transmission parameters includes a target transmit power, a target receive power, a PSD constraint, or a combination thereof.

[0150] In some examples, the number of RBs in the first set of frequency resources is based on a classification of the second wireless device.

[0151] In some examples, the classification of the second wireless device includes one of passive classification, semi-passive classification, semi-active classification, or active classification.

[0152] In some examples, the first set of frequency resources is continuous in frequency. In some examples, the second set of frequency resources is offset in frequency relative to the first set of frequency resources by a frequency shift value that is greater than the number of RBs in the first set of frequency resources.

[0153] In some examples, the first set of frequency resources is non-contiguous in frequency. In some examples, the second set of frequency resources is offset in frequency relative to the first set of frequency resources by a frequency shift value that is smaller than the interval between RBs of the first set of frequency resources.

[0154] Figure 9 A diagram illustrating a system 900 including a device 905 that supports frequency shifting in low-power devices according to one or more aspects of the present disclosure is shown. Device 905 may be an example of device 605, device 705, or UE 115 as described herein, or may include components of such devices. Device 905 may communicate (e.g., wirelessly) with one or more network entities 105, one or more UEs 115, or any combination thereof. Device 905 may include components for two-way voice and data communication, including components for sending and receiving communications, such as a communication manager 920, an input / output (I / O) controller 910, a transceiver 915, an antenna 925, a memory 930, code 935, and a processor 940. These components may be in electronic communication or otherwise coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more buses (e.g., bus 945).

[0155] I / O controller 910 can manage input and output signals for device 905. I / O controller 910 can also manage peripheral devices that are not integrated into device 905. In some cases, I / O controller 910 can represent a physical connection or port to an external peripheral device. In some cases, I / O controller 910 can utilize an operating system, such as or another known operating system. Additionally or alternatively, I / O controller 910 may represent or interact with a modem, keyboard, mouse, touch screen, or similar device. In some cases, I / O controller 910 may be implemented as part of a processor, such as processor 940. In some cases, a user may interact with device 905 via I / O controller 910 or via hardware components controlled by I / O controller 910.

[0156] In some cases, the device 905 may include a single antenna 925. However, in some other cases, the device 905 may have more than one antenna 925, which may be capable of concurrently transmitting or receiving multiple wireless transmissions. The transceiver 915 may communicate bidirectionally via one or more antennas 925, wired, or wireless links, as described herein. For example, the transceiver 915 may represent a wireless transceiver and may communicate bidirectionally with another wireless transceiver. The transceiver 915 may also include a modem for modulating packets; providing the modulated packets to the one or more antennas 925 for transmission; and demodulating packets received from the one or more antennas 925. The transceiver 915, or the transceiver 915 and the one or more antennas 925, may be examples of the transmitter 615, the transmitter 715, the receiver 610, the receiver 710, or any combination thereof, or components thereof, as described herein.

[0157] The memory 930 may include random access memory (RAM) and read-only memory (ROM). The memory 930 may store computer-readable, computer-executable code 935 including instructions that, when executed by the processor 940, cause the device 905 to perform the various functions described herein. The code 935 may be stored in a non-transitory computer-readable medium such as system memory or another type of memory. In some cases, the code 935 may not be directly executable by the processor 940, but may (e.g., when compiled and executed) cause the computer to perform the functions described herein. In some cases, the memory 930 may also contain, among other things, a basic I / O system (BIOS) that controls basic hardware or software operations, such as interaction with peripheral components or devices.

[0158] The processor 940 may include an intelligent hardware device (e.g., a general-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof). In some cases, the processor 940 may be configured to operate a memory array using a memory controller. In some other cases, the memory controller may be integrated into the processor 940. The processor 940 may be configured to execute computer-readable instructions stored in a memory (e.g., memory 930) to cause the device 905 to perform various functions (e.g., functions or tasks that support frequency shifting in low-power devices). For example, the device 905 or a component of the device 905 may include a processor 940 and a memory 930 coupled to or coupled to the processor 940, the processor 940 and the memory 930 being configured to perform the various functions described herein.

[0159] The communication manager 920 may support wireless communications at a first wireless device according to examples as disclosed herein. For example, the communication manager 920 may be configured to or otherwise support means for transmitting a continuous wave to a second wireless device via a first set of frequency resources and in accordance with a set of transmission parameters, wherein the continuous wave comprises a continuous waveform for activating the second wireless device. The communication manager 920 may be configured to or otherwise support means for receiving a backscatter signal of the continuous wave from the second wireless device via a second set of frequency resources, wherein the second set of frequency resources is offset in frequency relative to the first set of frequency resources.

[0160] Additionally or alternatively, the communication manager 920 may support wireless communications at a second wireless device according to examples as disclosed herein. For example, the communication manager 920 may be configured to or otherwise support means for receiving a continuous wave via a first set of frequency resources and in accordance with a set of transmit parameters, wherein the continuous wave comprises a continuous waveform for activating the second wireless device. The communication manager 920 may be configured to or otherwise support means for modulating the continuous wave with data based on the continuous waveform for activating the second wireless device. The communication manager 920 may be configured to or otherwise support means for transmitting a backscatter signal of the continuous wave via a second set of frequency resources based on modulating the continuous wave with data, wherein the second set of frequency resources is offset in frequency relative to the first set of frequency resources.

[0161] By including or configuring the communication manager 920 according to examples as described herein, the device 905 can support techniques for receiving backscatter signals via RBs that have been shifted in frequency, which can result in increased communication reliability, reduced latency, and improved inter-device coordination.

[0162] In some examples, the communication manager 920 can be configured to use or otherwise cooperate with the transceiver 915, one or more antennas 925, or any combination thereof to perform various operations (e.g., receive, monitor, transmit). Although the communication manager 920 is illustrated as a separate component, in some examples, one or more functions described with reference to the communication manager 920 can be supported or performed by the processor 940, the memory 930, the code 935, or any combination thereof. For example, the code 935 can include instructions that can be executed by the processor 940 to cause the device 905 to perform various aspects of frequency shifting in a low-power device as described herein, or the processor 940 and the memory 930 can be otherwise configured to perform or support such operations.

[0163] Figure 10 A flow chart illustrating a method 1000 for supporting frequency shifting in a low power device according to one or more aspects of the present disclosure is illustrated. The operations of the method 1000 may be implemented by a UE or components thereof as described herein. For example, the operations of the method 1000 may be implemented by a UE or components thereof as described herein. Figures 1 to 9 The described UE 115 performs. In some examples, the UE may execute an instruction set to control the functional elements of the UE to perform the described functions. Additionally or alternatively, the UE may use dedicated hardware to perform various aspects of the described functions.

[0164] At 1005, the method may include: transmitting a continuous wave to a second wireless device via a first set of frequency resources and according to a set of transmission parameters, wherein the continuous wave includes a continuous waveform for activating the second wireless device. The operations of 1005 may be performed according to the examples disclosed herein. In some examples, aspects of the operations of 1005 may be performed as described in reference to Figure 8 The continuous wave component 825 performs as described.

[0165] At 1010, the method may include receiving a continuous wave backscatter signal from a second wireless device and via a second set of frequency resources, wherein the second set of frequency resources is offset in frequency relative to the first set of frequency resources. The operations of 1010 may be performed according to examples disclosed herein. In some examples, aspects of the operations of 1010 may be performed as described in reference to Figure 8 The backscatter signal component 830 is described as performing.

[0166] Figure 11 A flow chart illustrating a method 1100 for supporting frequency shifting in a low power device according to one or more aspects of the present disclosure is illustrated. The operations of the method 1100 may be implemented by a UE or components thereof as described herein. For example, the operations of the method 1100 may be implemented by a UE or components thereof as described herein. Figures 1 to 9 The described UE 115 performs. In some examples, the UE may execute an instruction set to control the functional elements of the UE to perform the described functions. Additionally or alternatively, the UE may use dedicated hardware to perform various aspects of the described functions.

[0167] At 1105, the method may include receiving a message from a network entity, the message including an indication to communicate with a second wireless device, a number of RBs to be used in a first set of frequency resources, a target transmit power, a target receive power, a classification of the second wireless device, or a combination thereof. The operations of 1105 may be performed according to examples as disclosed herein. In some examples, aspects of the operations of 1105 may be performed by a method as described with reference to Figure 8 The receiving component 840 is described as executing.

[0168] At 1110, the method may include: transmitting a continuous wave to a second wireless device via a first set of frequency resources and according to a set of transmission parameters, wherein the continuous wave includes a continuous waveform for activating the second wireless device. The operations of 1110 may be performed according to examples disclosed herein. In some examples, aspects of the operations of 1110 may be performed as described in reference to Figure 8 The continuous wave component 825 performs as described.

[0169] At 1115, the method may include receiving a continuous wave backscatter signal from a second wireless device and via a second set of frequency resources, wherein the second set of frequency resources is offset in frequency relative to the first set of frequency resources. The operations of 1115 may be performed according to examples disclosed herein. In some examples, aspects of the operations of 1115 may be performed as described in reference to Figure 8 The backscatter signal component 830 is described as performing.

[0170] Figure 12 A flow chart illustrating a method 1200 for supporting frequency shifting in a low power device according to one or more aspects of the present disclosure is illustrated. The operations of the method 1200 may be implemented by a UE or components thereof as described herein. For example, the operations of the method 1200 may be implemented by a UE or components thereof as described herein. Figures 1 to 9 The described UE 115 performs. In some examples, the UE may execute an instruction set to control the functional elements of the UE to perform the described functions. Additionally or alternatively, the UE may use dedicated hardware to perform various aspects of the described functions.

[0171] At 1205, the method may include: receiving a continuous wave via a first set of frequency resources and according to a set of transmission parameters, wherein the continuous wave includes a continuous waveform for activating a second wireless device. The operations of 1205 may be performed according to examples disclosed herein. In some examples, aspects of the operations of 1205 may be performed as described in reference to Figure 8 The continuous wave component 825 performs as described.

[0172] At 1210, the method may include modulating a continuous wave with data based on a continuous waveform for activating a second wireless device. The operations of 1210 may be performed according to examples as disclosed herein. In some examples, aspects of the operations of 1210 may be performed as described in reference to Figure 8 The modulation component 835 performs as described.

[0173] At 1215, the method may include transmitting a backscatter signal of a continuous wave via a second set of frequency resources based on modulating the continuous wave with data, wherein the second set of frequency resources is offset in frequency relative to the first set of frequency resources. The operations of 1215 may be performed according to examples disclosed herein. In some examples, aspects of the operations of 1215 may be performed as described in reference to Figure 8 The backscatter signal component 830 is described as performing.

[0174] Figure 13 A flow chart illustrating a method 1300 for supporting frequency shifting in a low power device according to one or more aspects of the present disclosure is illustrated. The operations of the method 1300 may be implemented by a UE or components thereof as described herein. For example, the operations of the method 1300 may be implemented by a UE or components thereof as described herein. Figures 1 to 9The described UE 115 performs. In some examples, the UE may execute an instruction set to control the functional elements of the UE to perform the described functions. Additionally or alternatively, the UE may use dedicated hardware to perform various aspects of the described functions.

[0175] At 1305, the method may include transmitting a message indicating the ability to perform frequency shifting. The operations of 1305 may be performed according to examples as disclosed herein. In some examples, aspects of the operations of 1305 may be performed as described in reference to Figure 8 The described capability component 845 performs.

[0176] At 1310, the method may include: receiving a continuous wave via a first set of frequency resources and according to a set of transmission parameters, wherein the continuous wave includes a continuous waveform for activating a second wireless device. The operations of 1310 may be performed according to examples disclosed herein. In some examples, aspects of the operations of 1310 may be performed as described in reference to Figure 8 The continuous wave component 825 performs as described.

[0177] At 1315, the method may include modulating the continuous wave with data based on the continuous waveform used to activate the second wireless device. The operations of 1315 may be performed according to the examples disclosed herein. In some examples, aspects of the operations of 1315 may be performed as described in reference to Figure 8 The modulation component 835 performs as described.

[0178] At 1320, the method may include transmitting a continuous wave backscatter signal via a second set of frequency resources based on modulating the continuous wave with data, wherein the second set of frequency resources is offset in frequency relative to the first set of frequency resources. The operations of 1320 may be performed according to examples disclosed herein. In some examples, aspects of the operations of 1320 may be performed as described in reference to Figure 8 The backscatter signal component 830 is described as performing.

[0179] The following provides an overview of various aspects of the disclosure:

[0180] Aspect 1: A method for wireless communication at a first wireless device, the method comprising: transmitting a continuous wave to a second wireless device via a first set of frequency resources and according to a set of transmission parameters, wherein the continuous wave comprises a continuous waveform for activating the second wireless device; and receiving a backscattered signal of the continuous wave from the second wireless device and via a second set of frequency resources, wherein the second set of frequency resources is offset in frequency relative to the first set of frequency resources.

[0181] Aspect 2: According to the method according to Aspect 1, the method also includes: receiving a message from a network entity, the message including an indication to communicate with the second wireless device, the number of RBs to be used in the first frequency resource set, the target transmit power, the target receive power, the classification of the second wireless device, or a combination thereof, wherein sending the continuous wave via the first frequency resource set is at least partially based on the message.

[0182] Aspect 3: According to the method described in any one of Aspects 1 to 2, the method further includes: receiving a message including the ability of the second wireless device to perform frequency shift, wherein receiving the backscatter signal via the second frequency resource set that is offset in frequency relative to the first frequency resource set is at least partially based on the message.

[0183] Aspect 4: According to the method described in any one of Aspects 1 to 3, the method further includes: receiving a message indicating a frequency shift value of the second frequency resource set, wherein the second frequency resource set is shifted in frequency relative to the first frequency resource set at least in part based on the frequency shift value.

[0184] Aspect 5: The method according to any one of aspects 1 to 4, further comprising: sending an indication of the first set of frequency resources, the frequency shift value, or both for the continuous wave to a third wireless device.

[0185] Aspect 6: According to the method described in any one of Aspects 1 to 5, the method further includes: performing channel estimation on the channel between the first wireless device and the second wireless device based at least in part on the continuous wave; and performing time and frequency correction to decode the backscattered signal based at least in part on performing the channel estimation.

[0186] Aspect 7: A method according to any one of Aspects 1 to 6, wherein the first frequency resource set is continuous in frequency; and the second frequency resource set is offset in frequency relative to the first frequency resource set by a frequency shift value greater than the number of RBs of the first frequency resource set.

[0187] Aspect 8: A method according to any one of Aspects 1 to 6, wherein the first frequency resource set is non-continuous in frequency; and the second frequency resource set is offset in frequency relative to the first frequency resource set by a frequency shift value that is smaller than the interval between RBs of the first frequency resource set.

[0188] Aspect 9: A method according to any one of Aspects 1 to 8, wherein the number of RBs in the first frequency resource set is at least partially based on the transmission parameter set, and the transmission parameter set includes a target transmission power, a target reception power, a PSD constraint or a combination thereof.

[0189] Aspect 10: The method according to any one of aspects 1 to 9, wherein the number of RBs in the first set of frequency resources is based at least in part on the classification of the second wireless device.

[0190] Aspect 11: The method of aspect 10, wherein the classification of the second wireless device comprises one of passive classification, semi-passive classification, semi-active classification, or active classification.

[0191] Aspect 12: The method according to any one of aspects 1 to 11, wherein the second set of frequency resources is offset in frequency relative to the first set of frequency resources based at least in part on a frequency shift value, the frequency shift value being preconfigured at the first wireless device.

[0192] Aspect 13: A method for wireless communication at a second wireless device, the method comprising: receiving a continuous wave via a first set of frequency resources and based on a set of transmission parameters, wherein the continuous wave comprises a continuous waveform for activating the second wireless device; modulating the continuous wave with data based at least in part on the continuous waveform for activating the second wireless device; and transmitting a backscattered signal of the continuous wave via the second set of frequency resources based at least in part on modulating the continuous wave with data, wherein the second set of frequency resources is offset in frequency relative to the first set of frequency resources.

[0193] Aspect 14: The method according to Aspect 13 further includes: transmitting a message indicating the ability to perform frequency shift, wherein transmitting the backscatter signal via the second set of frequency resources that are offset in frequency relative to the first set of frequency resources is at least partially based on the ability to perform the frequency shift.

[0194] Aspect 15: The method according to any one of aspects 13 to 14, wherein the continuous wave is received from a first wireless device and the backscattered signal is transmitted to a third wireless device.

[0195] Aspect 16: The method according to any one of aspects 13 to 15, wherein the second set of frequency resources is offset in frequency relative to the first set of frequency resources based at least in part on a frequency shift value.

[0196] Aspect 17: A method according to any one of Aspects 13 to 16, wherein the number of RBs in the first frequency resource set is at least partially based on the transmission parameter set, and the transmission parameter set includes a target transmission power, a target reception power, a PSD constraint or a combination thereof.

[0197] Aspect 18: The method according to any one of aspects 13 to 17, wherein the number of RBs in the first set of frequency resources is based at least in part on the classification of the second wireless device.

[0198] Aspect 19: The method of aspect 18, wherein the classification of the second wireless device comprises one of passive classification, semi-passive classification, semi-active classification, or active classification.

[0199] Aspect 20: A method according to any one of Aspects 13 to 19, wherein the first frequency resource set is continuous in frequency; and the second frequency resource set is offset in frequency relative to the first frequency resource set by a frequency shift value greater than the number of RBs of the first frequency resource set.

[0200] Aspect 21: A method according to any one of Aspects 13 to 19, wherein the first frequency resource set is non-continuous in frequency; and the second frequency resource set is offset in frequency relative to the first frequency resource set by a frequency shift value that is smaller than the interval between RBs of the first frequency resource set.

[0201] Aspect 22: An apparatus for wireless communication at a first wireless device, the apparatus comprising: a processor; a memory coupled to the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform a method according to any one of aspects 1 to 12.

[0202] Aspect 23: An apparatus for wireless communication at a first wireless device, the apparatus comprising at least one means for performing the method according to any one of aspects 1 to 12.

[0203] Aspect 24: A non-transitory computer-readable medium storing code for wireless communication at a first wireless device, the code comprising instructions executable by a processor to perform the method according to any one of aspects 1 to 12.

[0204] Aspect 25: An apparatus for wireless communication at a second wireless device, the apparatus comprising: a processor; a memory coupled to the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform a method according to any one of Aspects 13 to 21.

[0205] Aspect 26: An apparatus for wireless communication at a second wireless device, the apparatus comprising: at least one component for performing the method according to any one of aspects 13 to 21.

[0206] Aspect 27: A non-transitory computer-readable medium storing code for wireless communication at a second wireless device, the code comprising instructions executable by a processor to perform the method according to any one of aspects 13 to 21.

[0207] It should be noted that the methods described herein describe possible implementations, and that the operations and steps may be rearranged or otherwise modified and that other implementations are possible. Furthermore, aspects of two or more of these methods may be combined.

[0208] Although aspects of LTE, LTE-A, LTE-A Pro, or NR systems may be described for example purposes, and LTE, LTE-A, LTE-A Pro, or NR terminology may be used throughout much of the description, the techniques described herein may also be applicable to networks other than LTE, LTE-A, LTE-A Pro, or NR networks. For example, the techniques described may be applicable to various other wireless communication systems, such as Ultra Mobile Broadband (UMB), Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDM, and other systems and radio technologies not explicitly mentioned herein.

[0209] The information and signals described herein may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips referred to throughout the description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0210] The various illustrative blocks and components described in conjunction with the disclosure herein may be implemented or executed using a general purpose processor, a DSP, an ASIC, a CPU, an FPGA or other programmable logic device, discrete gate or transistor logic components, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration).

[0211] The functions described herein may be implemented using hardware, software executed by a processor, firmware, or any combination thereof. When implemented using software executed by a processor, the functions may be stored as one or more instructions or codes of a computer-readable medium or sent using one or more instructions or codes of a computer-readable medium. Other examples and specific implementations are within the scope of this disclosure and the appended claims. For example, due to the nature of software, the functions described herein may be implemented using software executed by a processor, hardware, firmware, hard wiring, or a combination of any of these. Features that implement the functions may also be physically located at different locations, including being distributed so that parts of the functions are implemented at different physical locations.

[0212] Computer-readable medium includes both non-transient computer storage media and communication media, and it includes any medium that promotes a computer program to be transferred from one location to another location.Non-transient storage medium can be any available medium that can be accessed by a general or special-purpose computer.By way of example and not limitation, non-transient computer-readable medium can include RAM, ROM, electrically erasable programmable ROM (EEPROM), flash memory, compact disc (CD) ROM or other optical disc storage, disk storage or other magnetic storage device or can be used for carrying or storing desired program code components and any other non-transient medium that can be accessed by a general or special-purpose computer or a general or special-purpose processor in the form of an instruction or data structure.Moreover, any connection is appropriately referred to as computer-readable medium.For example, if software is sent from a website, server or other remote source using coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL) or wireless technologies such as infrared, radio and microwave, then coaxial cable, fiber optic cable, twisted pair, DSL or wireless technologies such as infrared, radio and microwave are included in the definition of computer-readable medium. As used herein, disk and optical disc include CD, laser disc, optical disc, digital versatile disc (DVD), floppy disk and Blu-ray disc. Magnetic disk can reproduce data magnetically, and optical disc can reproduce data optically using lasers. Combinations of the above are also included within the scope of computer-readable media.

[0213] As used herein (including in the claims), "or" used in a list of items (e.g., a list of items followed by a phrase such as "at least one of" or "one or more of") indicates an inclusive list, so that, for example, a list of at least one of A, B, or C means A or B or C or AB or AC or BC or ABC (i.e., A and B and C). Moreover, as used herein, the phrase "based on" should not be interpreted as a reference to a closed set of conditions. For example, an example step described as "based on condition A" can be based on both condition A and condition B without departing from the scope of this disclosure. In other words, as used herein, the phrase "based on" should be interpreted in the same manner as the phrase "based at least in part on."

[0214] The term "determining" encompasses a variety of actions, and thus, "determining" may include calculating, computing, processing, deriving, investigating, looking up (such as via looking up in a table, database, or other data structure), ascertaining, and the like. Furthermore, "determining" may include receiving (e.g., receiving information), accessing (e.g., accessing data stored in a memory), etc. Furthermore, "determining" may include parsing, retrieving, selecting, choosing, establishing, and other such similar actions.

[0215] In the accompanying drawings, similar components or features may have the same reference label. In addition, various components of the same type may be distinguished by following the reference label with a dash and a second label to distinguish between similar components. If only the first reference label is used in the specification, the description applies to any of the similar components having the same first reference label, regardless of the second reference label or other subsequent reference labels.

[0216] The description set forth herein in conjunction with the accompanying drawings describes example configurations and does not represent all examples that may be implemented or within the scope of the claims. The term "example" as used herein means "serving as an example, instance, or illustration," rather than "preferred" or "having advantages over other examples." The detailed description includes specific details to provide an understanding of the described technology. However, these technologies may be practiced without these specific details. In some cases, known structures and devices are shown in block diagram form to avoid obscuring the concepts of the described examples.

[0217] The description herein is provided to enable one of ordinary skill in the art to make or use the present disclosure. Various modifications to the present disclosure will be apparent to those of ordinary skill in the art, and the general principles defined herein may be applied to other variations without departing from the scope of the present disclosure. Thus, the present disclosure is not limited to the examples and designs described herein, but should be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An apparatus for wireless communication at a first wireless device, the apparatus comprising: Memory; and a processor coupled to the memory and configured to: transmitting a continuous wave to a second wireless device via a first set of frequency resources and according to a set of transmission parameters, wherein the continuous wave comprises a continuous waveform for activating the second wireless device; as well as The continuous wave backscatter signal is received from the second wireless device and via a second set of frequency resources, wherein the second set of frequency resources is offset in frequency relative to the first set of frequency resources.

2. The apparatus of claim 1 , wherein the processor is further configured to: A message is received from a network entity, the message including an indication to communicate with the second wireless device, a number of resource blocks to use in the first set of frequency resources, a target transmit power, a target receive power, a classification of the second wireless device, or a combination thereof, wherein transmitting the continuous wave via the first set of frequency resources is based at least in part on the message.

3. The apparatus of claim 1 , wherein the processor is further configured to: A message is received including an ability of the second wireless device to perform a frequency shift, wherein receiving the backscatter signal via the second set of frequency resources offset in frequency relative to the first set of frequency resources is based at least in part on the message.

4. The apparatus of claim 1 , wherein the processor is further configured to: A message is received indicating a frequency shift value for the second set of frequency resources, wherein the second set of frequency resources is offset in frequency relative to the first set of frequency resources based at least in part on the frequency shift value.

5. The apparatus of claim 1 , wherein the processor is further configured to: An indication of the first set of frequency resources, a frequency shift value, or both for the continuous wave is sent to a third wireless device.

6. The apparatus of claim 1 , wherein the processor is further configured to: performing channel estimation on a channel between the first wireless device and the second wireless device based at least in part on the continuous wave; and Time and frequency corrections are performed to decode the backscatter signal based at least in part on performing the channel estimation.

7. The apparatus according to claim 1, wherein: The first frequency resource set is continuous in frequency; and The second frequency resource set is shifted in frequency relative to the first frequency resource set by a frequency shift value that is greater than the number of resource blocks in the first frequency resource set.

8. The apparatus according to claim 1, wherein: The first frequency resource set is non-contiguous in frequency; and The second frequency resource set is shifted in frequency relative to the first frequency resource set by a frequency shift value that is smaller than an interval between resource blocks of the first frequency resource set.

9. The apparatus according to claim 1, wherein: The number of resource blocks in the first set of frequency resources is based at least in part on the set of transmit parameters, the set of transmit parameters comprising a target transmit power, a target receive power, a power spectral density constraint, or a combination thereof.

10. The apparatus of claim 1, wherein a number of resource blocks in the first set of frequency resources is based at least in part on a classification of the second wireless device.

11. The apparatus of claim 10, wherein the classification of the second wireless device comprises one of passive classification, semi-passive classification, semi-active classification, or active classification.

12. The apparatus of claim 1, wherein the second set of frequency resources is offset in frequency relative to the first set of frequency resources based at least in part on a frequency shift value, the frequency shift value being preconfigured at the first wireless device.

13. An apparatus for wireless communication at a second wireless device, the apparatus comprising: Memory; and a processor coupled to the memory and configured to: receiving a continuous wave via a first set of frequency resources and according to a set of transmission parameters, wherein the continuous wave comprises a continuous waveform for activating the second wireless device; modulating the continuous wave with data based at least in part on the continuous waveform used to activate the second wireless device; and A backscatter signal of the continuous wave is transmitted via a second set of frequency resources based at least in part on modulating the continuous wave with data, wherein the second set of frequency resources is offset in frequency relative to the first set of frequency resources.

14. The apparatus of claim 13, wherein the processor is further configured to: A message is transmitted indicating an ability to perform a frequency shift, wherein transmitting the backscatter signal via the second set of frequency resources offset in frequency relative to the first set of frequency resources is based at least in part on the ability to perform the frequency shift.

15. The apparatus of claim 13, wherein the continuous wave is received from a first wireless device and the backscattered signal is transmitted to a third wireless device.

16. The apparatus of claim 13, wherein the second set of frequency resources is offset in frequency relative to the first set of frequency resources based at least in part on a frequency shift value.

17. The apparatus of claim 13, wherein: The number of resource blocks in the first set of frequency resources is based at least in part on the set of transmit parameters, the set of transmit parameters comprising a target transmit power, a target receive power, a power spectral density constraint, or a combination thereof.

18. The apparatus of claim 13, wherein a number of resource blocks in the first set of frequency resources is based at least in part on a classification of the second wireless device.

19. The apparatus of claim 18, wherein the classification of the second wireless device comprises one of passive classification, semi-passive classification, semi-active classification, or active classification.

20. The apparatus of claim 13, wherein: The first frequency resource set is continuous in frequency; and The second frequency resource set is shifted in frequency relative to the first frequency resource set by a frequency shift value that is greater than the number of resource blocks in the first frequency resource set.

21. The apparatus of claim 13, wherein: The first frequency resource set is non-contiguous in frequency; and The second frequency resource set is shifted in frequency relative to the first frequency resource set by a frequency shift value that is smaller than an interval between resource blocks of the first frequency resource set.

22. A method for wireless communication at a first wireless device, the method comprising: transmitting a continuous wave to a second wireless device via a first set of frequency resources and according to a set of transmission parameters, wherein the continuous wave comprises a continuous waveform for activating the second wireless device; as well as The continuous wave backscatter signal is received from the second wireless device and via a second set of frequency resources, wherein the second set of frequency resources is offset in frequency relative to the first set of frequency resources.

23. The method according to claim 22, further comprising: A message is received from a network entity, the message including an indication to communicate with the second wireless device, a number of resource blocks to use in the first set of frequency resources, a target transmit power, a target receive power, a classification of the second wireless device, or a combination thereof, wherein transmitting the continuous wave via the first set of frequency resources is based at least in part on the message.

24. The method according to claim 22, further comprising: A message is received including an ability of the second wireless device to perform a frequency shift, wherein receiving the backscatter signal via the second set of frequency resources shifted in frequency relative to the first set of frequency resources is based at least in part on the message.

25. The method according to claim 22, further comprising: A message is received indicating a frequency shift value for the second set of frequency resources, wherein the second set of frequency resources is offset in frequency relative to the first set of frequency resources based at least in part on the frequency shift value.

26. The method according to claim 22, further comprising: An indication of the first set of frequency resources, a frequency shift value, or both for the continuous wave is sent to a third wireless device.

27. The method according to claim 22, further comprising: performing channel estimation on a channel between the first wireless device and the second wireless device based at least in part on the continuous wave; as well as Time and frequency corrections are performed to decode the backscatter signal based at least in part on performing the channel estimation.

28. The method of claim 22, wherein: The first frequency resource set is continuous in frequency; and The second frequency resource set is shifted in frequency relative to the first frequency resource set by a frequency shift value that is greater than the number of resource blocks in the first frequency resource set.

29. A method for wireless communication at a second wireless device, the method comprising: receiving a continuous wave via a first set of frequency resources and according to a set of transmission parameters, wherein the continuous wave comprises a continuous waveform for activating the second wireless device; modulating the continuous wave with data based at least in part on the continuous waveform used to activate the second wireless device; and A backscatter signal of the continuous wave is transmitted via a second set of frequency resources based at least in part on modulating the continuous wave with data, wherein the second set of frequency resources is offset in frequency relative to the first set of frequency resources.

30. The method of claim 29, further comprising: A message is transmitted indicating an ability to perform a frequency shift, wherein transmitting the backscatter signal via the second set of frequency resources offset in frequency relative to the first set of frequency resources is based at least in part on the ability to perform the frequency shift.

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