Techniques for increasing energy utilization of storage capacitors

Abstract

Certain aspects of the present disclosure are directed towards an apparatus for energy harvesting (700). The apparatus (700) generally includes: an energy harvesting circuit (702); a reconfigurable capacitor circuit (710) coupled to an output (704) of the energy harvesting circuit (702); a voltage converter (706) having an input coupled to the output (704) of the energy harvesting circuit (702); and a controller (708) circuit having a supply input coupled to an output (716) of the voltage converter (706) and an output coupled to at least one control input of the reconfigurable capacitor circuit (710).

Description

Qualcomm Ref. No.: 2405563WO 1TECHNIQUES FOR INCREASING ENERGY UTILIZATION OF STORAGECAPACITORSCROSS-REFERENCE TO RELATED APPLICATION(S)

[0001] This application claims priority to U.S. Patent Application No. 18 / 890,639, filed September 19, 2024, which is hereby incorporated by reference herein.BACKGROUNDField of the Disclosure

[0002] Aspects of the present disclosure relate to electronic devices, and more particularly, to techniques for increasing energy utilization of storage capacitorsDescription of Related Art

[0003] Wireless communications systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, broadcasts, or other similar types of services. These wireless communications systems may employ multiple-access technologies capable of supporting communications with multiple users by sharing available wireless communications system resources with those users. In some cases, wireless communications systems may be implemented with energy harvesting.

[0004] Although wireless communications systems have made great technological advancements over many years, challenges still exist. For example, complex and dynamic environments can still attenuate or block signals between wireless transmitters and wireless receivers. Accordingly, there is a continuous desire to improve the technical performance of wireless communications systems, including, for example: increasing energy harvesting efficiency, improving speed and data carrying capacity of communications, improving efficiency of the use of shared communications mediums, reducing power used by transmitters and receivers while performing communications, improving reliability of wireless communications, avoiding redundant transmissions and / or receptions and related processing, improving the coverage area of wireless communications, increasing the number and types of devices that can access wireless communications systems, increasing the ability for different types of devices to intercommunicate, increasing the number and type of wireless communications mediums available for use, and the like.P+S Ref. No.: QUAL / 2405563PCQualcomm Ref. No.: 2405563WO 2SUMMARY

[0005] Certain aspects of the present disclosure are directed towards an apparatus for energy harvesting. The apparatus generally includes: an energy harvesting circuit; a reconfigurable capacitor circuit coupled to an output of the energy harvesting circuit; a voltage converter having an input coupled to the output of the energy harvesting circuit; and a controller circuit having a supply input coupled to an output of the voltage converter and an output coupled to at least one control input of the reconfigurable capacitor circuit.

[0006] Certain aspects of the present disclosure are directed towards a method for energy harvesting. The method generally includes: generating, via an energy harvesting circuit, an energy harvesting voltage at an output of the energy harvesting circuit; generating, via a converter, a supply voltage based on the energy harvesting voltage; and controlling, via a controller circuit, a reconfigurable capacitor circuit coupled to the output of the energy harvesting circuit using the supply voltage.

[0007] Certain aspects of the present disclosure are directed towards a wireless device. The wireless device generally includes: an antenna; an energy harvesting circuit coupled to the antenna; a reconfigurable capacitor circuit coupled to an output of the energy harvesting circuit; a voltage converter having an input coupled to the output of the energy harvesting circuit; and a controller circuit having a supply input coupled to an output of the voltage converter and an output coupled to at least one control input of the reconfigurable capacitor circuit.

[0008] The following description and the appended figures set forth certain features for purposes of illustration.BRIEF DESCRIPTION OF DRAWINGS

[0009] The appended figures depict certain features of the various aspects described herein and are not to be considered limiting of the scope of this disclosure.

[0010] FIG. 1 depicts an example wireless communications network.

[0011] FIG. 2 depicts an example disaggregated base station architecture.

[0012] FIG. 3 depicts aspects of an example base station and an example user equipment.P+S Ref. No.: QUAL / 2405563PCQualcomm Ref. No.: 2405563WO 3

[0013] FIGS. 4A, 4B, 4C, and 4D depict various example aspects of data structures for a wireless communications network.

[0014] FIG. 5 depicts an example radio frequency identification (RFID) system.

[0015] FIG. 6 depicts an example system that utilizes a network entity to communicate with ambient internet of things (loT) devices.

[0016] FIG. 7 illustrates an electronic device implemented with energy harvesting, in accordance with certain aspects of the present disclosure.

[0017] FIG. 8 illustrates different configurations of a reconfigurable storage capacitor circuit, in accordance with certain aspects of the present disclosure.

[0018] FIG. 9 is a graph illustrating an output voltage when a reconfigurable storage capacitor circuit is in parallel and series configurations, in accordance with certain aspects of the present disclosure.

[0019] FIG. 10 illustrates different configurations of a reconfigurable storage capacitor circuit implemented with four capacitive elements, in accordance with certain aspects of the present disclosure.

[0020] FIG. 11 is a flow diagram illustrating example operations for energy harvesting, in accordance with certain aspects of the present disclosure.

[0021] To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements disclosed in one aspect may be beneficially utilized on other aspects without specific recitation.DETAILED DESCRIPTION

[0022] Certain aspects are directed towards a reconfigurable storage capacitor network that facilitates a greater amount of energy harvested and stored in capacitive elements to be used to power a load. For example, the reconfigurable storage capacitor circuit may include capacitive elements that may be configurable via switches to be either in parallel or in series. The capacitive elements may be in parallel until the voltage provided to the load reaches some lower threshold, at which point the capacitive elementsP+S Ref. No.: QUAL / 2405563PCQualcomm Ref. No.: 2405563WO 4 may be coupled in series to increase the voltage provided to the load and allow for continued operation of the load. In some aspects, the electronic device may be implemented without a battery. Thus, the electronic device may also include a converter to power control logic for the reconfigurable storage capacitor circuit using the harvested energy, as described in more detail herein. Thus, some aspects increase the utilization of energy stored in capacitive elements in a manner that can be implemented in devices (e.g., tags) without batteries.

[0023] In some cases, the multi-stage rectifier may be used for energy harvesting. A new generation of wireless devices may overcome conventional drawbacks of onboard energy storage by harvesting energy from wireless signals (e.g., radio frequency (RF) signals) to perform various circuit operations such as wireless communications. Such energy harvesting devices (e.g., user equipment (UE)) may include, for example, RFID devices (e.g., RFID tags) that are capable of receiving signals and “backscattering” these received signals to another device to perform wireless communications. RFID devices are generally categorized into three type of devices: passive, semi-passive, and active. Passive RFID devices typically have no energy storage and communicate via backscattering. Semi-passive RFID devices have limited energy storage and communicate via backscattering. Active RFID devices have energy storage and are capable of active transmission (generating RF signals).

[0024] These aforementioned passive and semi-passive RFID devices may rely partially or entirely on harvested energy from received signals to perform wireless communications (e.g., via backscattering signals). Thus, energy-harvesting (EH) devices (e.g., passive internet of things (IoT) / ambient loT devices) may be considered a type of UE that provides low-cost and low-power solutions for many applications in a wireless communications system.

[0025] In some use cases, EH is used for tasks like data decoding, data reception, data encoding, and data transmission. In such cases, the EH device may have a small energy storage unit to store the harvested energy, and the stored energy may be used to perform data decoding, encoding, filtering, processing, and the like. In other cases, the purpose is not to charge a phone battery in full, but to charge the battery of a device (such as a wearable, smartwatch, or UE with low power or use a dedicated battery for EH) in a way that enables some tasks to be performed using the harvested energy. Various tasks suchP+S Ref. No.: QUAL / 2405563PCQualcomm Ref. No.: 2405563WO 5 as data decoding, operating some filters, data encoding, transmitting, or receiving data may be performed through the accumulation of energy harvested over time. In some cases, the EH mode of operation can occur when a UE battery is at low levels, and energyharvesting modes can be used. In some cases, the EH device can work in low-power modes by the UE or when the UE decides to use such low-power modes.Introduction to Wireless Communications Networks

[0026] The techniques and methods described herein may be used for various wireless communications networks. While aspects may be described herein using terminology commonly associated with 3G, 4G, and / or 5G wireless technologies, aspects of the present disclosure may likewise be applicable to other communications systems and standards not explicitly mentioned herein.

[0027] FIG. 1 depicts an example of a wireless communications network 100, in which aspects described herein may be implemented.

[0028] Generally, wireless communications network 100 includes various network entities (alternatively, network elements or network nodes). A network entity is generally a communications device and / or a communications function performed by a communications device (e.g., a user equipment (UE), a base station (BS), a component of a BS, a server, etc.). For example, various functions of a network as well as various devices associated with and interacting with a network may be considered network entities. Further, wireless communications network 100 includes terrestrial aspects, such as ground-based network entities (e.g., BSs 102), and non-terrestrial aspects, such as satellite 140 and aircraft 145, which may include network entities on-board (e.g., one or more BSs) capable of communicating with other network elements (e.g., terrestrial BSs) and user equipments.

[0029] In the depicted example, wireless communications network 100 includes BSs 102, UEs 104, and one or more core networks, such as an Evolved Packet Core (EPC) 160 and 5G Core (5GC) network 190, which interoperate to provide communications services over various communications links, including wired and wireless links.

[0030] FIG. 1 depicts various example UEs 104, which may more generally include: a cellular phone, smart phone, session initiation protocol (SIP) phone, laptop, personal digital assistant (PDA), satellite radio, global positioning system, multimedia device,P+S Ref. No.: QUAL / 2405563PCQualcomm Ref. No.: 2405563WO 6 video device, digital audio player, camera, game console, tablet, smart device, wearable device, vehicle, electric meter, gas pump, large or small kitchen appliance, healthcare device, implant, sensor / actuator, display, internet of things (loT) devices, always on (AON) devices, edge processing devices, or other similar devices. UEs 104 may also be referred to more generally as a mobile device, a wireless device, a wireless communications device, a station, a mobile station, a subscriber station, a mobile subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a remote device, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, a handset, and others.

[0031] BSs 102 wirelessly communicate with (e.g., transmit signals to or receive signals from) UEs 104 via communications links 120. The communications links 120 between BSs 102 and UEs 104 may include uplink (UL) (also referred to as reverse link) transmissions from a UE 104 to a BS 102 and / or downlink (DL) (also referred to as forward link) transmissions from a BS 102 to a UE 104. The communications links 120 may use multiple-input and multiple-output (MIMO) antenna technology, including spatial multiplexing, beamforming, and / or transmit diversity in various aspects.

[0032] BSs 102 may generally include: a NodeB, enhanced NodeB (eNB), next generation enhanced NodeB (ng-eNB), next generation NodeB (gNB or gNodeB), access point, base transceiver station, radio base station, radio transceiver, transceiver function, transmission reception point, and / or others. Each of BSs 102 may provide communications coverage for a respective geographic coverage area 110, which may sometimes be referred to as a cell, and which may overlap in some cases (e.g., small cell 102’ may have a coverage area 110’ that overlaps the coverage area 110 of a macro cell). A BS may, for example, provide communications coverage for a macro cell (covering relatively large geographic area), a pico cell (covering relatively smaller geographic area, such as a sports stadium), a femto cell (relatively smaller geographic area (e.g., a home)), and / or other types of cells.

[0033] While BSs 102 are depicted in various aspects as unitary communications devices, BSs 102 may be implemented in various configurations. For example, one or more components of a base station may be disaggregated, including a central unit (CU), one or more distributed units (DUs), one or more radio units (RUs), a Near-Real Time (Near-RT) RAN Intelligent Controller (RIC), or a Non-Real Time (Non-RT) RIC, toP+S Ref. No.: QUAL / 2405563PCQualcomm Ref. No.: 2405563WO 7 name a few examples. In another example, various aspects of a base station may be virtualized. More generally, a base station (e.g., BS 102) may include components that are located at a single physical location or components located at various physical locations. In examples in which a base station includes components that are located at various physical locations, the various components may each perform functions such that, collectively, the various components achieve functionality that is similar to a base station that is located at a single physical location. In some aspects, a base station including components that are located at various physical locations may be referred to as a disaggregated radio access network architecture, such as an Open RAN (O-RAN) or Virtualized RAN (VRAN) architecture. FIG. 2 depicts and describes an example disaggregated base station architecture.

[0034] Different BSs 102 within wireless communications network 100 may also be configured to support different radio access technologies, such as 3G, 4G, and / or 5G. For example, BSs 102 configured for 4G LTE (collectively referred to as Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E- UTRAN)) may interface with the EPC 160 through first backhaul links 132 (e.g., an SI interface). BSs 102 configured for 5G (e.g., 5G New Radio (NR) or Next Generation RAN (NG-RAN)) may interface with 5GC network 190 through second backhaul links 184. BSs 102 may communicate directly or indirectly (e.g., through the EPC 160 or 5GC network 190) with each other over third backhaul links 134 (e.g., X2 interface), which may be wired or wireless.

[0035] Wireless communications network 100 may subdivide the electromagnetic spectrum into various classes, bands, channels, or other features. In some aspects, the subdivision is provided based on wavelength and frequency, where frequency may also be referred to as a carrier, a subcarrier, a frequency channel, a tone, or a subband. For example, 3GPP currently defines Frequency Range 1 (FR1) as including 410 MHz - 7125 MHz, which is often referred to (interchangeably) as “Sub-6 GHz.” Similarly, 3GPP currently defines Frequency Range 2 (FR2) as including 24,250 MHz - 71,000 MHz, which is sometimes referred to (interchangeably) as a “millimeter wave” (“mmW” or “mmWave”). In some cases, FR2 may be further defined in terms of sub-ranges, such as a first sub-range FR2-1 including 24,250 MHz - 52,600 MHz and a second sub-range FR2-2 including 52,600 MHz - 71,000 MHz. A base station configured to communicateP+S Ref. No.: QUAL / 2405563PCQualcomm Ref. No.: 2405563WO 8 using mmWave / near mmWave radio frequency bands (e.g., a mmWave base station such as BS 180) may utilize beamforming (e.g., 182) with a UE (e.g., 104) to improve path loss and range.

[0036] The communications links 120 between BSs 102 and, for example, UEs 104, may be through one or more carriers, which may have different bandwidths (e.g., 5, 10, 15, 20, 100, 400, and / or other MHz), and which may be aggregated in various aspects. Carriers may or may not be adjacent to each other. Allocation of carriers may be asymmetric with respect to DL and UL (e.g., more or fewer carriers may be allocated for DL than for UL).

[0037] Communications using higher frequency bands may have higher path loss and a shorter range compared to lower frequency communications. Accordingly, certain base stations (e.g., 180 in FIG. 1) may utilize beamforming 182 with a UE 104 to improve path loss and range. For example, BS 180 and the UE 104 may each include a plurality of antennas, such as antenna elements, antenna panels, and / or antenna arrays to facilitate the beamforming. In some cases, BS 180 may transmit a beamformed signal to UE 104 in one or more transmit directions 182’. UE 104 may receive the beamformed signal from the BS 180 in one or more receive directions 182”. UE 104 may also transmit a beamformed signal to the BS 180 in one or more transmit directions 182”. BS 180 may also receive the beamformed signal from UE 104 in one or more receive directions 182’. BS 180 and UE 104 may then perform beam training to determine the best receive and transmit directions for each of BS 180 and UE 104. Notably, the transmit and receive directions for BS 180 may or may not be the same. Similarly, the transmit and receive directions for UE 104 may or may not be the same.

[0038] Wireless communications network 100 further includes a Wi-Fi access point (AP) 150 in communication with Wi-Fi stations (STAs) 152 via communications links 154 in, for example, a 2.4 GHz and / or 5 GHz unlicensed frequency spectrum.

[0039] Certain UEs 104 may communicate with each other using device-to-device (D2D) communications link 158. D2D communications link 158 may use one or more sidelink channels, such as a physical sidelink broadcast channel (PSBCH), a physical sidelink discovery channel (PSDCH), a physical sidelink shared channel (PSSCH), aP+S Ref. No.: QUAL / 2405563PCQualcomm Ref. No.: 2405563WO 9 physical sidelink control channel (PSCCH), and / or a physical sidelink feedback channel (PSFCH).

[0040] EPC 160 may include various functional components, including: a Mobility Management Entity (MME) 162, other MMEs 164, a Serving Gateway 166, a Multimedia Broadcast Multicast Service (MBMS) Gateway 168, a Broadcast Multicast Service Center (BM-SC) 170, and / or a Packet Data Network (PDN) Gateway 172, such as in the depicted example. MME 162 may be in communication with a Home Subscriber Server (HSS) 174. MME 162 is the control node that processes the signaling between the UEs 104 and the EPC 160. Generally, MME 162 provides bearer and connection management.

[0041] Generally, user Internet protocol (IP) packets are transferred through Serving Gateway 166, which itself is connected to PDN Gateway 172. PDN Gateway 172 provides UE IP address allocation as well as other functions. PDN Gateway 172 and the BM-SC 170 are connected to IP Services 176, which may include, for example, the Internet, an intranet, an IP Multimedia Subsystem (IMS), a Packet Switched (PS) streaming service, and / or other IP services.

[0042] BM-SC 170 may provide functions for MBMS user service provisioning and delivery. BM-SC 170 may serve as an entry point for content provider MBMS transmission, may be used to authorize and initiate MBMS Bearer Services within a public land mobile network (PLMN), and / or may be used to schedule MBMS transmissions. MBMS Gateway 168 may be used to distribute MBMS traffic to the BSs 102 belonging to a Multicast Broadcast Single Frequency Network (MBSFN) area broadcasting a particular service, and / or may be responsible for session management (start / stop) and for collecting MBMS-related charging information.

[0043] 5GC network 190 may include various functional components, including: an Access and Mobility Management Function (AMF) 192, other AMFs 193, a Session Management Function (SMF) 194, and a User Plane Function (UPF) 195. AMF 192 may be in communication with Unified Data Management (UDM) 196.

[0044] AMF 192 is a control node that processes signaling between UEs 104 and 5GC network 190. AMF 192 provides, for example, quality of service (QoS) flow and session management.P+S Ref. No.: QUAL / 2405563PCQualcomm Ref. No.: 2405563WO 10

[0045] Internet protocol (IP) packets are transferred through UPF 195, which is connected to the IP Services 197, and which provides UE IP address allocation as well as other functions for 5GC network 190. IP Services 197 may include, for example, the Internet, an intranet, an IMS, a PS streaming service, and / or other IP services.

[0046] In various aspects, a network entity or network node can be implemented as an aggregated base station, as a disaggregated base station, a component of a base station, an integrated access and backhaul (IAB) node, a relay node, a sidelink node, to name a few examples.

[0047] FIG. 2 depicts an example disaggregated base station 200 architecture. The disaggregated base station 200 architecture may include one or more central units (CUs) 210 that can communicate directly with a core network 220 via a backhaul link, or indirectly with the core network 220 through one or more disaggregated base station units (such as a Near-Real Time (Near-RT) RAN Intelligent Controller (RIC) 225 via an E2 link, or a Non-Real Time (Non-RT) RIC 215 associated with a Service Management and Orchestration (SMO) Framework 205, or both). A CU 210 may communicate with one or more distributed units (DUs) 230 via respective midhaul links, such as an Fl interface. The DUs 230 may communicate with one or more radio units (RUs) 240 via respective fronthaul links. The RUs 240 may communicate with respective UEs 104 via one or more radio frequency (RF) access links. In some implementations, the UE 104 may be simultaneously served by multiple RUs 240.

[0048] Each of the units, e.g., the CUs 210, the DUs 230, the RUs 240, as well as the Near-RT RICs 225, the Non-RT RICs 215 and the SMO Framework 205, may include one or more interfaces or be coupled to one or more interfaces configured to receive or transmit signals, data, or information (collectively, signals) via a wired or wireless transmission medium. Each of the units, or an associated processor or controller providing instructions to the communications interfaces of the units, can be configured to communicate with one or more of the other units via the transmission medium. For example, the units can include a wired interface configured to receive or transmit signals over a wired transmission medium to one or more of the other units. Additionally or alternatively, the units can include a wireless interface, which may include a receiver, a transmitter or transceiver (such as a radio frequency (RF) transceiver), configured toP+S Ref. No.: QUAL / 2405563PCQualcomm Ref. No.: 2405563WO 11 receive or transmit signals, or both, over a wireless transmission medium to one or more of the other units.

[0049] In some aspects, the CU 210 may host one or more higher layer control functions. Such control functions can include radio resource control (RRC), packet data convergence protocol (PDCP), service data adaptation protocol (SDAP), or the like. Each control function can be implemented with an interface configured to communicate signals with other control functions hosted by the CU 210. The CU 210 may be configured to handle user plane functionality (e.g., Central Unit - User Plane (CU-UP)), control plane functionality (e.g., Central Unit - Control Plane (CU-CP)), or a combination thereof. In some implementations, the CU 210 can be logically split into one or more CU-UP units and one or more CU-CP units. The CU-UP unit can communicate bidirectionally with the CU-CP unit via an interface, such as the El interface when implemented in an O- RAN configuration. The CU 210 can be implemented to communicate with the DU 230 for network control and signaling.

[0050] The DU 230 may correspond to a logical unit that includes one or more base station functions to control the operation of one or more RUs 240. In some aspects, the DU 230 may host one or more of a radio link control (RLC) layer, a medium access control (MAC) layer, and one or more high physical (PHY) layers (such as modules for forward error correction (FEC) encoding and decoding, scrambling, modulation and demodulation, or the like) depending, at least in part, on a functional split, such as those defined by the 3rdGeneration Partnership Project (3GPP). In some aspects, the DU 230 may further host one or more low PHY layers. Each layer (or module) can be implemented with an interface configured to communicate signals with other layers (and modules) hosted by the DU 230, or with the control functions hosted by the CU 210.

[0051] Lower-layer functionality can be implemented by one or more RUs 240. In some deployments, an RU 240, controlled by a DU 230, may correspond to a logical node that hosts RF processing functions, or low-PHY layer functions (such as performing fast Fourier transform (FFT), inverse FFT (iFFT), digital beamforming, physical random access channel (PRACH) extraction and filtering, or the like), or both, based at least in part on the functional split, such as a lower layer functional split. In such an architecture, the RU(s) 240 can be implemented to handle over the air (OTA) communications with one or more UEs 104. In some implementations, real-time and non-real-time aspects ofP+S Ref. No.: QUAL / 2405563PCQualcomm Ref. No.: 2405563WO 12 control and user plane communications with the RU(s) 240 can be controlled by the corresponding DU 230. In some scenarios, this configuration can enable the DU(s) 230 and the CU 210 to be implemented in a cloud-based RAN architecture, such as a VRAN architecture.

[0052] The SMO Framework 205 may be configured to support RAN deployment and provisioning of non-virtualized and virtualized network elements. For nonvirtualized network elements, the SMO Framework 205 may be configured to support the deployment of dedicated physical resources for RAN coverage which may be managed via an operations and maintenance interface (such as an 01 interface). For virtualized network elements, the SMO Framework 205 may be configured to interact with a cloud computing platform (such as an open cloud (O-Cloud) 290) to perform network element life cycle management (such as to instantiate virtualized network elements) via a cloud computing platform interface (such as an 02 interface). Such virtualized network elements can include, but are not limited to, CUs 210, DUs 230, RUs 240 and Near-RT RICs 225. In some implementations, the SMO Framework 205 can communicate with a hardware aspect of a 4G RAN, such as an open eNB (O-eNB) 211, via an 01 interface. Additionally, in some implementations, the SMO Framework 205 can communicate directly with one or more RUs 240 via an 01 interface. The SMO Framework 205 also may include a Non-RT RIC 215 configured to support functionality of the SMO Framework 205.

[0053] The Non-RT RIC 215 may be configured to include a logical function that enables non-real-time control and optimization of RAN elements and resources, artificial intelligence / machine learning (AI / ML) workflows including model training and updates, or policy -based guidance of applications / features in the Near-RT RIC 225. The Non-RT RIC 215 may be coupled to or communicate with (such as via an Al interface) the Near- RT RIC 225. The Near-RT RIC 225 may be configured to include a logical function that enables near-real-time control and optimization of RAN elements and resources via data collection and actions over an interface (such as via an E2 interface) connecting one or more CUs 210, one or more DUs 230, or both, as well as an O-eNB, with the Near-RT RIC 225.

[0054] In some implementations, to generate AI / ML models to be deployed in the Near-RT RIC 225, the Non-RT RIC 215 may receive parameters or external enrichmentP+S Ref. No.: QUAL / 2405563PCQualcomm Ref. No.: 2405563WO 13 information from external servers. Such information may be utilized by the Near-RT RIC 225 and may be received at the SMO Framework 205 or the Non-RT RIC 215 from nonnetwork data sources or from network functions. In some examples, the Non-RT RIC 215 or the Near-RT RIC 225 may be configured to tune RAN behavior or performance. For example, the Non-RT RIC 215 may monitor long-term trends and patterns for performance and employ AI / ML models to perform corrective actions through the SMO Framework 205 (such as reconfiguration via 01) or via creation of RAN management policies (such as Al policies).

[0055] FIG. 3 depicts aspects of an example BS 102 and a UE 104.

[0056] Generally, BS 102 includes various processors (e.g., 320, 330, 338, and 340), antennas 334a-t (collectively “antennas 334”), transceivers 332a-t (collectively “transceivers 332”), which include modulators and demodulators, and other aspects, which enable wireless transmission of data (e.g., data source 312) and wireless reception of data (e.g., data sink 339). For example, BS 102 may send and receive data between BS 102 and UE 104. BS 102 includes controller / processor 340, which may be configured to implement various functions described herein related to wireless communications.

[0057] Generally, UE 104 includes various processors (e.g., 358, 364, 366, and 380), antennas 352a-r (collectively “antennas 352”), transceivers 354a-r (collectively “transceivers 354”), which include modulators and demodulators, and other aspects, which enable wireless transmission of data (e.g., retrieved from data source 362) and wireless reception of data (e.g., provided to data sink 360). UE 104 includes controller / processor 380, which may be configured to implement various functions described herein related to wireless communications.

[0058] In regards to an example downlink transmission, BS 102 includes a transmit processor 320 that may receive data from a data source 312 and control information from a controller / processor 340. The control information may be for the physical broadcast channel (PBCH), physical control format indicator channel (PCFICH), physical hybrid automatic repeat request (HARQ) indicator channel (PHICH), physical downlink control channel (PDCCH), group common PDCCH (GC PDCCH), and / or others. The data may be for the physical downlink shared channel (PDSCH), in some examples.P+S Ref. No.: QUAL / 2405563PCQualcomm Ref. No.: 2405563WO 14

[0059] Transmit processor 320 may process (e.g., encode and symbol map) the data and control information to obtain data symbols and control symbols, respectively. Transmit processor 320 may also generate reference symbols, such as for the primary synchronization signal (PSS), secondary synchronization signal (SSS), PBCH demodulation reference signal (DMRS), and channel state information reference signal (CSI-RS).

[0060] Transmit (TX) multiple-input multiple-output (MIMO) processor 330 may perform spatial processing (e.g., precoding) on the data symbols, the control symbols, and / or the reference symbols, if applicable, and may provide output symbol streams to the modulators (MODs) in transceivers 332a-332t. Each modulator in transceivers 332a- 332t may process a respective output symbol stream to obtain an output sample stream. Each modulator may further process (e.g., convert to analog, amplify, filter, and upconvert) the output sample stream to obtain a downlink signal. Downlink signals from the modulators in transceivers 332a-332t may be transmitted via the antennas 334a-334t, respectively.

[0061] In order to receive the downlink transmission, UE 104 includes antennas 352a- 352r that may receive the downlink signals from the BS 102 and may provide received signals to the demodulators (DEMODs) in transceivers 354a-354r, respectively. Each demodulator in transceivers 354a-354r may condition (e.g., filter, amplify, downconvert, and digitize) a respective received signal to obtain input samples. Each demodulator may further process the input samples to obtain received symbols.

[0062] MIMO detector 356 may obtain received symbols from all the demodulators in transceivers 354a-354r, perform MIMO detection on the received symbols if applicable, and provide detected symbols. Receive processor 358 may process (e.g., demodulate, deinterleave, and decode) the detected symbols, provide decoded data for the UE 104 to a data sink 360, and provide decoded control information to a controller / processor 380.

[0063] In regards to an example uplink transmission, UE 104 further includes a transmit processor 364 that may receive and process data (e.g., for the physical uplink shared channel (PUSCH)) from a data source 362 and control information (e.g., for the physical uplink control channel (PUCCH)) from the controller / processor 380. TransmitP+S Ref. No.: QUAL / 2405563PCQualcomm Ref. No.: 2405563WO 15 processor 364 may also generate reference symbols for a reference signal (e.g., for the sounding reference signal (SRS)). The symbols from the transmit processor 364 may be precoded by a TX MIMO processor 366 if applicable, further processed by the modulators in transceivers 354a-354r (e.g., for single-carrier frequency division multiplexing (SC- FDM)), and transmitted to BS 102.

[0064] At BS 102, the uplink signals from UE 104 may be received by antennas 334a- t, processed by the demodulators in transceivers 332a-332t, detected by a MIMO detector 336 if applicable, and further processed by a receive processor 338 to obtain decoded data and control information sent by UE 104. Receive processor 338 may provide the decoded data to a data sink 339 and the decoded control information to the controller / processor 340.

[0065] Memories 342 and 382 may store data and program codes for BS 102 and UE 104, respectively.

[0066] Scheduler 344 may schedule UEs for data transmission on the downlink and / or uplink.

[0067] In various aspects, BS 102 may be described as transmitting and receiving various types of data associated with the methods described herein. In these contexts, “transmitting” may refer to various mechanisms of outputting data, such as outputting data from data source 312, scheduler 344, memory 342, transmit processor 320, controller / processor 340, TX MIMO processor 330, transceivers 332a-t, antenna 334a-t, and / or other aspects described herein. Similarly, “receiving” may refer to various mechanisms of obtaining data, such as obtaining data from antennas 334a-t, transceivers 332a-t, receive (RX) MIMO detector 336, controller / processor 340, receive processor 338, scheduler 344, memory 342, and / or other aspects described herein.

[0068] In various aspects, UE 104 may likewise be described as transmitting and receiving various types of data associated with the methods described herein. In these contexts, “transmitting” may refer to various mechanisms of outputting data, such as outputting data from data source 362, memory 382, transmit processor 364, controller / processor 380, TX MIMO processor 366, transceivers 354a-t, antenna 352a-t, and / or other aspects described herein. Similarly, “receiving” may refer to various mechanisms of obtaining data, such as obtaining data from antennas 352a-t, transceiversP+S Ref. No.: QUAL / 2405563PCQualcomm Ref. No.: 2405563WO 16354a-t, RX MIMO detector 356, controller / processor 380, receive processor 358, memory 382, and / or other aspects described herein.

[0069] In some aspects, one or more processors may be configured to perform various operations, such as those associated with the methods described herein, and transmit (output) to or receive (obtain) data from another interface that is configured to transmit or receive, respectively, the data.

[0070] FIGS. 4A, 4B, 4C, and 4D depict aspects of data structures for a wireless communications network, such as wireless communications network 100 of FIG. 1.

[0071] In particular, FIG. 4A is a diagram 400 illustrating an example of a first subframe within a 5G (e.g., 5GNR) frame structure, FIG. 4B is a diagram 430 illustrating an example of DL channels within a 5G subframe, FIG. 4C is a diagram 450 illustrating an example of a second subframe within a 5G frame structure, and FIG. 4D is a diagram 480 illustrating an example of UL channels within a 5G subframe.

[0072] Wireless communications systems may utilize orthogonal frequency division multiplexing (OFDM) with a cyclic prefix (CP) on the uplink and downlink. Such systems may also support half-duplex operation using time division duplexing (TDD). OFDM and single-carrier frequency division multiplexing (SC-FDM) partition the system bandwidth (e.g., as depicted in FIGS. 4B and 4D) into multiple orthogonal subcarriers. Each subcarrier may be modulated with data. Modulation symbols may be sent in the frequency domain with OFDM and / or in the time domain with SC-FDM.

[0073] A wireless communications frame structure may be frequency division duplex (FDD), in which, for a particular set of subcarriers, subframes within the set of subcarriers are dedicated for either DL or UL. Wireless communications frame structures may also be time division duplex (TDD), in which, for a particular set of subcarriers, subframes within the set of subcarriers are dedicated for both DL and UL.

[0074] In FIG. 4A and 4C, the wireless communications frame structure is TDD where D is DL, U is UL, and X is flexible for use between DL / UL. UEs may be configured with a slot format through a received slot format indicator (SFI) (dynamically through DL control information (DCI), or semi-statically / statically through radio resource control (RRC) signaling). In the depicted examples, a 10 ms frame is divided into 10P+S Ref. No.: QUAL / 2405563PCQualcomm Ref. No.: 2405563WO 17 equally sized 1 ms subframes. Each subframe may include one or more time slots. In some examples, each slot may include 7 or 14 symbols, depending on the slot format. Subframes may also include mini-slots, which generally have fewer symbols than an entire slot. Other wireless communications technologies may have a different frame structure and / or different channels.

[0075] In certain aspects, the number of slots within a subframe is based on a slot configuration and a numerology. For example, for slot configuration 0, different numerol ogies (p) 0 to 6 allow for 1, 2, 4, 8, 16, 32, and 64 slots, respectively, per subframe. For slot configuration 1, different numerol ogies 0 to 2 allow for 2, 4, and 8 slots, respectively, per subframe. Accordingly, for slot configuration 0 and numerology p, there are 14 symbols / slot and 2p slots / subframe. The subcarrier spacing and symbol length / duration are a function of the numerology. The subcarrier spacing may be equal to 2^ X 15 kHz, where p is the numerology 0 to 6. As such, the numerology p = 0 has a subcarrier spacing of 15 kHz and the numerology p = 6 has a subcarrier spacing of 960 kHz. The symbol length / duration is inversely related to the subcarrier spacing. FIGS. 4A, 4B, 4C, and 4D provide an example of slot configuration 0 with 14 symbols per slot and numerology p = 2 with 4 slots per subframe. The slot duration is 0.25 ms, the subcarrier spacing is 60 kHz, and the symbol duration is approximately 16.67 ps.

[0076] As depicted in FIGS. 4 A, 4B, 4C, and 4D, a resource grid may be used to represent the frame structure. Each time slot includes a resource block (RB) (also referred to as physical RBs (PRBs)) that extends, for example, 12 consecutive subcarriers. The resource grid is divided into multiple resource elements (REs). The number of bits carried by each RE depends on the modulation scheme.

[0077] As illustrated in FIG. 4A, some of the REs carry reference (pilot) signals (RS) for aUE (e.g., UE 104 of FIGS. 1 and 3). The RS may include demodulation RS (DMRS) and / or channel state information reference signals (CSI-RS) for channel estimation at the UE. The RS may also include beam measurement RS (BRS), beam refinement RS (BRRS), and / or phase tracking RS (PT-RS).

[0078] FIG. 4B illustrates an example of various DL channels within a subframe of a frame. The physical downlink control channel (PDCCH) carries DCI within one or moreP+S Ref. No.: QUAL / 2405563PCQualcomm Ref. No.: 2405563WO 18 control channel elements (CCEs), each CCE including, for example, nine RE groups (REGs), each REG including, for example, four consecutive REs in an OFDM symbol.

[0079] A primary synchronization signal (PSS) may be within symbol 2 of particular subframes of a frame. The PSS is used by a UE (e.g., 104 of FIGS. 1 and 3) to determine subframe / symbol timing and a physical layer identity.

[0080] A secondary synchronization signal (SSS) may be within symbol 4 of particular subframes of a frame. The SSS is used by a UE to determine a physical layer cell identity group number and radio frame timing.

[0081] Based on the physical layer identity and the physical layer cell identity group number, the UE can determine a physical cell identifier (PCI). Based on the PCI, the UE can determine the locations of the aforementioned DMRS. The physical broadcast channel (PBCH), which carries a master information block (MIB), may be logically grouped with the PSS and SSS to form a synchronization signal (SS) / PBCH block. The MIB provides a number of RBs in the system bandwidth and a system frame number (SFN). The physical downlink shared channel (PDSCH) carries user data, broadcast system information not transmitted through the PBCH such as system information blocks (SIBs), and / or paging messages.

[0082] As illustrated in FIG. 4C, some of the REs carry DMRS (indicated as R for one particular configuration, but other DMRS configurations are possible) for channel estimation at the base station. The UE may transmit DMRS for the PUCCH and DMRS for the PUSCH. The PUSCH DMRS may be transmitted, for example, in the first one or two symbols of the PUSCH. The PUCCH DMRS may be transmitted in different configurations depending on whether short or long PUCCHs are transmitted and depending on the particular PUCCH format used. UE 104 may transmit sounding reference signals (SRS). The SRS may be transmitted, for example, in the last symbol of a subframe. The SRS may have a comb structure, and a UE may transmit SRS on one of the combs. The SRS may be used by a base station for channel quality estimation to enable frequency-dependent scheduling on the UL.

[0083] FIG. 4D illustrates an example of various UL channels within a subframe of a frame. The PUCCH may be located as indicated in one configuration. The PUCCH carries uplink control information (UCI), such as scheduling requests, a channel qualityP+S Ref. No.: QUAL / 2405563PCQualcomm Ref. No.: 2405563WO 19 indicator (CQI), a precoding matrix indicator (PMI), a rank indicator (RI), and HARQ acknowledged / not acknowledged (ACK / NACK) feedback. The PUSCH carries data, and may additionally be used to carry a buffer status report (BSR), a power headroom report (PHR), and / or UCI.Introduction to Energy Harvesting in RFID Systems

[0084] Radio frequency identification (RFID) is a rapidly growing technology impacting many industries due to its economic potential for inventory / asset management within warehouses, internet of things (loT), sustainable sensor networks in factories and / or agriculture, and smart homes, to name a few example applications. RFID technology includes RFID devices (or backscatter devices), such as transponders, or tags, that emit an information-bearing signal upon receiving an energizing signal.

[0085] In certain aspects, RFID devices may be operated without a battery. Generally, RFID devices that are operated without a battery are known as passive RFID devices. Passive RFID devices may operate by harvesting energy from received radio frequency signals (e.g., “over the air”), thereby powering reception and transmission circuitry within the RFID devices. This harvested energy allows passive RFID devices to transmit information, sometimes referred to as backscatter-modulated information, without using a local power source within the RFID device. On the other hand, in certain aspects, an RFID device may be semi-passive and include on-board energy storage to supplement the RFID device’s ability to harvest energy from received signals (however, at higher cost).

[0086] In certain aspects, in addition to harvesting power from RF sources, energyharvesting devices may accumulate energy from other direct energy sources, such as solar energy, in order to supplement these devices’ power demands. Semi-passive energyharvesting devices may, in some cases, include power-consuming components, such as analog-to-digital converters (ADCs), mixers, and oscillators.

[0087] Thus, RFID devices are a type of user equipment (UE) that provides low-cost and low-power solutions for many applications in a wireless communications system. Such devices may be power efficient, sometimes consuming less than 0.1 mW of power to operate. Further, their relatively simple architectures and, in some cases, lack of battery, mean that such devices can be small, lightweight, and easily installed orP+S Ref. No.: QUAL / 2405563PCQualcomm Ref. No.: 2405563WO 20 integrated in many types of environments or host devices. Generally speaking then, RFID devices provide practical solutions to many networking applications that use low-cost, small -footprint, durable, maintenance-free, and long-lifespan communications devices. For example, RFID devices may be configured as long endurance industrial sensors, which mitigate the problems of replacing batteries in and around dangerous machinery.

[0088] FIG. 5 shows an example RFID system 500. As shown, RFID system 500 includes a reader 510 and an RFID tag 550. Reader 510 may also be referred to as an interrogator or a scanner. RFID tag 550 may also be referred to as an interrogator, RFID label, or an electronics label. In certain aspects, reader 510 is a network entity (e.g., such as a gNB), and RFID tag 550 is a user equipment (UE).

[0089] Reader 510 includes an antenna 520 and an electronics unit 530. Antenna 520 radiates signals transmitted by reader 510 and receives signals from RFID tags and / or other devices. Electronics unit 530 may include a transmitter and a receiver for reading RFID tags such as RFID tag 550. The same pair of transmitter and receiver (or another pair of transmitter and receiver) may support bi-directional communication with wireless networks, wireless devices, etc. Electronics unit 530 may include processing circuitry (e.g., a processor) to perform processing for data being transmitted and received by the RFID reader 510.

[0090] As shown, RFID tag 550 includes an antenna 560 and a data storage element 570. Antenna 560 radiates signals transmitted by RFID tag 550 and receives signals from RFID reader 510 and / or other devices. Data storage element 570 stores information for RFID tag 550, for example, in an electrically erasable programmable read-only memory (EEPROM) or another type of memory. RFID tag 550 may also include an electronics unit that can process the received signal and generate the signals to be transmitted.

[0091] In certain aspects, RFID tag 550 may be a passive RFID tag having no battery. In this case, induction may be used to power the RFID tag 550. For example, in some cases, a magnetic field from a signal transmitted by reader 510 may induce an electrical current in RFID tag 550, which may then operate based on the induced current. RFID tag 550 can radiate its signal in response to receiving a signal from RFID reader 510 or some other device. In certain other aspects, RFID tag 550 may optionally include an energyP+S Ref. No.: QUAL / 2405563PCQualcomm Ref. No.: 2405563WO 21 storage device 590, such as a battery, capacitor, etc., for storing energy harvested using energy harvesting circuitry 555, as described below.

[0092] In some examples, RFID tag 550 may be read by placing the reader 510 within close proximity to RFID tag 550. Reader 510 may radiate a first signal 525 via the antenna 520. In some cases, the first signal 525 may be known as an interrogation signal or energy signal. In some cases, energy of the first signal 525 may be coupled from reader antenna 520 to RFID tag antenna 560 via magnetic coupling and / or other phenomena. In other words, the RFID tag 550 may receive the first signal 525 from reader 510 via antenna 560, and energy of the first signal 525 may be harvested using energy harvesting circuitry 555 (e.g., an RF transducer) and used to power RFID tag 550. For example, energy of the first signal 525 received by RFID tag 550 may be used to power a microprocessor 545 of RFID tag 550. Microprocessor 545 may, in turn, retrieve information stored in the data storage element 570 of RFID tag 550 and the antenna 560 transmits the retrieved information via a second signal 535. For example, in some cases, microprocessor 545 may generate the second signal 535 by modulating a baseband signal (e.g., generated using energy of the first signal 525) with the information retrieved from the data storage element 570. In some cases, this second signal 535 may be known as a backscatter modulated information signal. Thereafter, as noted, microprocessor 545 provides the second signal 535 to reader 510. Reader 510 may receive the second signal 535 from RFID tag 550 via antenna 520 and may process (e.g., demodulate) the received signal to obtain the information of data storage element 570 sent in second signal 535.

[0093] In some cases, RFID system 500 may be designed to operate at 13.56 MHz or some other frequency (e.g., an ultra-high frequency (UHF) band at 900 MHz). Reader 510 may have a specified maximum transmit power level, which may be imposed by the Federal Communication Commission (FCC) in the United Stated or other regulatory bodies in other countries. The specified maximum transmit power level of reader 510 may limit the distance at which RFID tag 550 can be read by reader 510.

[0094] Wireless technology is increasingly useful in industrial applications, such as ultra-reliable low-latency communication (URLLC) and machine type communication (MTC). In such domains, and others, it is desirable to support devices (e.g., passive RFID tags) that are capable of harvesting energy from wireless energy sources (e.g., in lieu ofP+S Ref. No.: QUAL / 2405563PCQualcomm Ref. No.: 2405563WO 22 or in combination with a battery or other energy storage device, such as a capacitor), such as RF signals, thermal energy, solar energy, and the like.

[0095] FIG. 6 depicts an example system 600 that utilizes a network entity (e.g., BS 102) to communicate with ambient loT devices 650. The ambient loT devices 650 may be used to monitor a variety of devices and processes. For example, loT devices may be used to report sensor measurements, video signal s / images, light readings, and control devices (e.g., actuators).

[0096] Typical networks may not be able to efficiently support the most pervasive RFID-type of sensors, implemented as passive loT devices. Such devices may be used extensively in future use cases, such as asset management, logistics, warehousing, and manufacturing.

[0097] As illustrated in FIG. 6, a gNB may be able to read information stored on ambient loT devices and / or write information to ambient loT devices. The gNB can provide energy to the ambient loT devices (e.g., via a continuous wave signal) and an information-bearing signal may be reflected back (“backscattered) to the gNB. The gNB may read the reflected signal from the ambient loT device to decode the information transmitted by the loT devices 650.Aspects Related to Energy Harvesting

[0098] Battery-less energy harvesting tags used for inventory management or asset tracking applications have little stored energy due to capacitor size and cost. For a given storage capacitor size, the energy utilization of the storage capacitive element should be increased to enable longer operation time of tag sensors and transmitters and lower the device’ s effective cost. A tag may be turned on when the capacitor voltage is greater than an upper threshold voltage (e.g., also referred to as a maximum voltage (Vmax)). The tag may be turned off once the stored voltage decreases below a lower threshold voltage (e.g., also referred to as a minimum voltage (Vmin))

[0099] FIG. 7 illustrates an electronic device 700 implemented with energy harvesting, in accordance with certain aspects of the present disclosure. The electronic device 700 may include an energy harvesting circuit 702. The energy harvesting circuit 702 may use any suitable energy harvesting technique — such as energy harvesting from a radio frequency (RF) signal, solar energy, wind energy, tidal energy, mechanical energyP+S Ref. No.: QUAL / 2405563PCQualcomm Ref. No.: 2405563WO 23(e.g., vibration), or thermal energy — to capture energy from the ambient environment and convert this captured energy to electrical energy for use by the electronic device 700. For example, the energy harvesting circuit 702 may be implemented as an energy transducer, such as a solar cell or an antenna. The output of the energy harvesting circuit 702 may provide an output voltage (Vout) and may be coupled to a capacitive element 704. The Vout node may be selectively coupled to a load 714 via a switch 712 that may be controlled via a switch enable (SW EN) signal. The load 714 may be any circuit to be powered, such as a receiver (RX), a transmitter (TX), a sensor, or any logic.

[0100] The SW_EN signal may be used to enable the load 714 by closing the switch 712 when Vout is greater than Vmax (e.g., 1 V) and disable the load 714 by opening the switch 712 when Vout is less than Vmin (e.g., 0.6 V). In this case, the energy extracted from the capacitive element 704 may be equal to:C(Vmax2— Vmin2)2 where C is the capacitance of the capacitive element 704. However, when switch 712 is opened to disable the load, some energy is still stored in the capacitive element 704. That is, when Vout is equal to Vmin, the amount of energy still stored in the capacitive element 704 may be equal to:C x Vmin22The energy in the capacitive element 704 may remain unused if the switch 712 remains open. The remaining energy may be drained due to the leakage of the capacitive element 704 after the switch 712 is opened without powering the load 714. For example, if C is 1 pF, Vmax is 1 V, and Vmin 0.6 V, 36% of the energy stored in the capacitive element 704 may be unused and lost due to current leakage.

[0101] Certain aspects are directed towards a reconfigurable storage capacitor network that facilitates the usage of more energy stored in the capacitive element 704. For example, the electronic device 700 may include a reconfigurable storage capacitor circuit 710. The capacitor circuit 710 may include a capacitive element Ci and a capacitive element C2 that may be configurable via switches Si, S2, S3 to be either in parallel or in series. With the capacitor circuit 710, the capacitive element 704 may be removed or replaced with a small on-chip capacitive element.P+S Ref. No.: QUAL / 2405563PCQualcomm Ref. No.: 2405563WO 24

[0102] FIG. 8 illustrates different configurations of the reconfigurable storage capacitor circuit 710, in accordance with certain aspects of the present disclosure. As shown, in a parallel configuration 800, the capacitive elements may be configured in parallel by closing switches Si and S3 and opening switch S2. Thus, the voltage Vi on capacitive element Ci may be equal to voltage V2 on capacitive element C2, which may be equal to Vout. Vout may be equal to Vmax. The capacitor circuit 710 may remain in the parallel configuration 800 until Vout reaches Vmin. Then, the capacitor circuit 710 may configured in a series configuration 850 by opening switches Si and S3 and closing switch S2. Thus, assuming the capacitances of Ci and C2 are equal, Vout is now equal Vi plus V2. Assuming Vi and V2 are equal to Vmin, Vout is now equal to two times Vmin, as shown.

[0103] FIG. 9 is a graph 900 illustrating Vout when the capacitor circuit 710 is in parallel and series configurations, in accordance with certain aspects of the present disclosure. Initially, the capacitor circuit 710 may be in the parallel configuration and Vout may be equal to Vmax. Vout may reduce due to power consumption from the load until Vout reaches Vmin. Then, the capacitor circuit 710 may be reconfigured in the series configuration, increasing Vout to two times Vmin, allowing at least a portion of the remaining stored energy in the capacitor circuit 710 to power the load 714.

[0104] Referring back to FIG. 7, the electronic device 700 may also include a converter 706 and voltage sense and control logic 708 (e.g., a control circuit including a voltage sense circuit). The converter 706 may be implemented using any suitable voltage converter circuit such as a switched-mode power supply (SMPS) (e.g., a boost converter or a charge pump, such as a nanowatt charge pump). The converter 706 may generate a power supply voltage (Vsupply) for the voltage sense and control logic 708 based on Vout, enabling the control of the capacitor circuit 710 without the usage of a battery. A capacitive element 716 may be coupled to an output of the converter 706 and to a power supply input of the voltage sense and control logic 708 and may be used to store Vsupply. Using Vsupply, the voltage sense and control logic 708 may be used to sense Vout and control the switches Si, S2, and S3 of the capacitor circuit 710 in either parallel or series configurations, as described herein.

[0105] The amount of additional energy that can be extracted by configuring the capacitor circuit in the series configuration may be calculated based on expression:P+S Ref. No.: QUAL / 2405563PCQualcomm Ref. No.: 2405563WO 25’ / 2CiC2 / (Ci+C2)(Vmax2- Vmin2)For example, if Cl= C2 = 0.5 pF, the unused energy in the capacitor circuit 710 may be reduced to 20%. This process can be repeated further by using a greater number of smaller capacitive elements that can then be sequentially placed in series to extract more energy.

[0106] FIG. 10 illustrates different configurations of a capacitor circuit implemented with four capacitive elements, in accordance with certain aspects of the present disclosure. The capacitor circuit shown in FIG. 10 may be used in place of the capacitor circuit 710 of FIG. 7. As shown, the capacitor circuit may include capacitive elements Ci, C2, C3, and C4. The capacitor circuit may be in a parallel configuration 1000 by closing switches Si, S3, S4, Se, S7, and S9 and opening switches S2, Ss, and Ss. Voltage Vi, V2, V3, and V4 across respective capacitive elements Ci, C2, C3, and C4 may be equal to Vout and Vout may be equal to Vmax. Due to power consumption from the load, Vout decreases. When Vout reaches Vmin, the capacitor circuit may be reconfigured in a series-parallel configuration 1010 with the switches Si, S3, Ss, S7, and S9 open and switches S2, S4, Se, and Ss closed. In the series-parallel configuration 1010, the capacitive elements Ci and C2 are in series and capacitive elements C3 and C4 are in series, wherein the series circuit including capacitive elements Cl and C2 are in parallel with the series circuit including capacitive elements C3 and C4. Once in the series-parallel configuration 1010, Vout increases to two times Vmin. Vout may continue to decrease until Vout reaches Vmin again, at which point the capacitor circuit may be reconfigured in a series configuration 1020, as shown. In the series configuration 1020, switches Si, S4, Se, and S7 are open and the switches S2, Ss, and Ss are closed. Again, Vout may increase to two times Vmin, allowing more energy to be consumed from the capacitor circuit.Example Operations for Energy Harvesting

[0107] FIG. 11 is a flow diagram illustrating example operations 1100 for energy harvesting, in accordance with certain aspects of the present disclosure. The operations 1100 may be performed by an electronic device such as the electronic device 700 of FIG. 7.

[0108] At block 1102, the electronic device generates, via an energy harvesting circuit (e.g., energy harvesting circuit 702), an energy harvesting voltage (e.g., Vout shown in FIG. 7) at an output of the energy harvesting circuit. At block 1104, the electronic deviceP+S Ref. No.: QUAL / 2405563PCQualcomm Ref. No.: 2405563WO 26 generates, via a converter (e.g., converter 706), a supply voltage (e.g., Vsupply shown in FIG. 7) based on the energy harvesting voltage. At block 1106, the electronic device controls, via a controller circuit (e.g., control logic 708), a reconfigurable capacitor circuit (e.g., capacitor circuit 710) coupled to the output of the energy harvesting circuit using the supply voltage.

[0109] In some aspects, the electronic device stores, via the reconfigurable capacitor circuit, the energy harvesting voltage from the energy harvesting circuit. The electronic device may sense, via the controller circuit, the energy harvesting voltage, the reconfigurable capacitor circuit being controlled based on the sensed energy harvesting voltage.

[0110] In some aspects, controlling the reconfigurable capacitor circuit may include controlling one or more switches (e.g., Si, S2, S3 shown in FIG. 7) of the reconfigurable capacitor circuit. In some aspects, controlling the one or more switches may include: configuring the reconfigurable capacitor circuit (e.g., Ci and C2) with a first set of capacitive elements in parallel based on the energy harvesting voltage being greater than a first threshold voltage (e.g., Vmin) and configuring the reconfigurable capacitor circuit with the first set of capacitive elements in series based on the energy harvesting voltage being equal to or less than the first threshold voltage. A switch may be coupled between the output of the energy harvesting circuit and a load circuit (e.g., the load 714). The electronic device may close the switch when the energy harvesting voltage at the output of the energy harvesting circuit is greater than a second threshold voltage (e.g., Vmax), the second threshold voltage being greater than the first threshold voltage. In some aspects, the electronic device may maintain the switch in a closed state until the energy harvesting voltage at the output of the energy harvesting circuit is less than the first threshold voltage.Example Clauses

[0111] Aspect 1 : An apparatus for energy harvesting, comprising: an energy harvesting circuit; a reconfigurable capacitor circuit coupled to an output of the energy harvesting circuit; a voltage converter having an input coupled to the output of the energy harvesting circuit; and a controller circuit having a supply input coupled to an output of the voltage converter and an output coupled to at least one control input of the reconfigurable capacitor circuit.P+S Ref. No.: QUAL / 2405563PCQualcomm Ref. No.: 2405563WO 27

[0112] Aspect 2: The apparatus of Aspect 1, wherein the voltage converter comprises a charge pump.

[0113] Aspect 3: The apparatus of Aspect 1 or 2, wherein the reconfigurable capacitor circuit is configurable in a first configuration including parallel capacitive elements or in a second configuration including series capacitive elements.

[0114] Aspect 4: The apparatus of Aspect 3, wherein the reconfigurable capacitor circuit is configurable in a third configuration including a first set of series capacitive elements in parallel with a second set of series capacitive elements.

[0115] Aspect 5: The apparatus according to any of Aspects 1-4, wherein: the reconfigurable capacitor circuit is configured to store an energy harvesting voltage from the energy harvesting circuit; and the controller circuit comprises a voltage sense circuit configured to sense the energy harvesting voltage and control the reconfigurable capacitor circuit based on the sensed energy harvesting voltage.

[0116] Aspect 6: The apparatus of Aspect 5, wherein the controller circuit is configured to control one or more switches of the reconfigurable capacitor circuit.

[0117] Aspect 7: The apparatus of Aspect 6, wherein the controller circuit is configured to control the one or more switches to: configure the reconfigurable capacitor circuit with a first set of capacitive elements in parallel based on the sensed energy harvesting voltage being greater than a first threshold voltage; and configure the reconfigurable capacitor circuit with the first set of capacitive elements in series based on the sensed energy harvesting voltage being equal to or less than the first threshold voltage.

[0118] Aspect 8: The apparatus of Aspect 7, further comprising a switch coupled between the output of the energy harvesting circuit and a load circuit, wherein the switch is configured to be closed when the sensed energy harvesting voltage is greater than a second threshold voltage, the second threshold voltage being greater than the first threshold voltage.

[0119] Aspect 9: The apparatus of Aspect 8, wherein the switch is configured to remain closed until the sensed energy harvesting voltage is less than the first threshold voltage.P+S Ref. No.: QUAL / 2405563PCQualcomm Ref. No.: 2405563WO 28

[0120] Aspect 10: A method for energy harvesting, comprising: generating, via an energy harvesting circuit, an energy harvesting voltage at an output of the energy harvesting circuit; generating, via a converter, a supply voltage based on the energy harvesting voltage; and controlling, via a controller circuit, a reconfigurable capacitor circuit coupled to the output of the energy harvesting circuit using the supply voltage.

[0121] Aspect 11 : The method of Aspect 10, further comprising: storing, via the reconfigurable capacitor circuit, the energy harvesting voltage from the energy harvesting circuit; and sensing, via the controller circuit, the energy harvesting voltage, the reconfigurable capacitor circuit being controlled based on the sensed energy harvesting voltage.

[0122] Aspect 12: The method of Aspect 10 or 11, wherein controlling the reconfigurable capacitor circuit comprises controlling one or more switches of the reconfigurable capacitor circuit.

[0123] Aspect 13: The method of Aspect 12, wherein controlling the one or more switches comprises: configuring the reconfigurable capacitor circuit with a first set of capacitive elements in parallel based on the energy harvesting voltage being greater than a first threshold voltage; and configuring the reconfigurable capacitor circuit with the first set of capacitive elements in series based on the energy harvesting voltage being equal to or less than the first threshold voltage.

[0124] Aspect 14: The method of Aspect 13, wherein a switch is coupled between the output of the energy harvesting circuit and a load circuit, the method further comprising closing the switch when the energy harvesting voltage at the output of the energy harvesting circuit is greater than a second threshold voltage, the second threshold voltage being greater than the first threshold voltage.

[0125] Aspect 15: The method of Aspect 14, further comprising maintaining the switch in a closed state until the energy harvesting voltage at the output of the energy harvesting circuit is less than the first threshold voltage.

[0126] Aspect 16: A wireless device, comprising: an antenna; an energy harvesting circuit coupled to the antenna; a reconfigurable capacitor circuit coupled to an output of the energy harvesting circuit; a voltage converter having an input coupled to the outputP+S Ref. No.: QUAL / 2405563PCQualcomm Ref. No.: 2405563WO 29 of the energy harvesting circuit; and a controller circuit having a supply input coupled to an output of the voltage converter and an output coupled to at least one control input of the reconfigurable capacitor circuit.

[0127] Aspect 17: The wireless device of Aspect 16, wherein the voltage converter comprises a charge pump.

[0128] Aspect 18: The wireless device of Aspect 16 or 17, wherein the reconfigurable capacitor circuit is configurable in a first configuration including parallel capacitive elements or in a second configuration including series capacitive elements.

[0129] Aspect 19: The wireless device of Aspect 18, wherein the reconfigurable capacitor circuit is configurable in a third configuration including a first set of series capacitive elements in parallel with a second set of series capacitive elements.

[0130] Aspect 20: The wireless device according to any of Aspects 16-19, wherein: the reconfigurable capacitor circuit is configured to store an energy harvesting voltage from the energy harvesting circuit; and the controller circuit comprises a voltage sense circuit configured to sense the energy harvesting voltage and control the reconfigurable capacitor circuit based on the sensed energy harvesting voltage.Additional Considerations

[0131] The preceding description is provided to enable any person skilled in the art to practice the various aspects described herein. The examples discussed herein are not limiting of the scope, applicability, or aspects set forth in the claims. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects. For example, changes may be made in the function and arrangement of elements discussed without departing from the scope of the disclosure. Various examples may omit, substitute, or add various procedures or components as appropriate. For instance, the methods described may be performed in an order different from that described, and various actions may be added, omitted, or combined. Also, features described with respect to some examples may be combined in some other examples. For example, an apparatus may be implemented or a method may be practiced using any number of the aspects set forth herein. In addition, the scope of the disclosure is intended to cover such an apparatus or method that is practiced using other structure, functionality, or structure and functionality in addition to,P+S Ref. No.: QUAL / 2405563PCQualcomm Ref. No.: 2405563WO 30 or other than, the various aspects of the disclosure set forth herein. It should be understood that any aspect of the disclosure disclosed herein may be embodied by one or more elements of a claim.

[0132] The various illustrative logical blocks, modules, and circuits described in connection with the present disclosure may be implemented or performed with a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device (PLD), discrete gate or transistor logic, 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 commercially available 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, a system on a chip (SoC), or any other such configuration.

[0133] As used herein, “a processor,” “at least one processor” or “one or more processors” generally refers to a single processor configured to perform one or multiple operations or multiple processors configured to collectively perform one or more operations. In the case of multiple processors, performance of the one or more operations could be divided amongst different processors, though one processor may perform multiple operations, and multiple processors could collectively perform a single operation. Similarly, “a memory,” “at least one memory” or “one or more memories” generally refers to a single memory configured to store data and / or instructions, multiple memories configured to collectively store data and / or instructions.

[0134] As used herein, a phrase referring to “at least one of’ a list of items refers to any combination of those items, including single members. As an example, “at least one of: a, b, or c” is intended to cover a, b, c, a-b, a-c, b-c, and a-b-c, as well as any combination with multiples of the same element (e.g., a-a, a-a-a, a-a-b, a-a-c, a-b-b, a-c-c, b-b, b-b-b, b-b-c, c-c, and c-c-c or any other ordering of a, b, and c).

[0135] As used herein, the term “determining” encompasses a wide variety of actions. For example, “determining” may include calculating, computing, processing, deriving,P+S Ref. No.: QUAL / 2405563PCQualcomm Ref. No.: 2405563WO 31 investigating, looking up (e.g., looking up in a table, a database or another data structure), ascertaining, and the like. Also, “determining” may include receiving (e.g., receiving information), accessing (e.g., accessing data in a memory), and the like. Also, “determining” may include resolving, selecting, choosing, establishing, and the like.

[0136] The methods disclosed herein comprise one or more actions for achieving the methods. The method actions may be interchanged with one another without departing from the scope of the claims. In other words, unless a specific order of actions is specified, the order and / or use of specific actions may be modified without departing from the scope of the claims. Further, the various operations of methods described above may be performed by any suitable means capable of performing the corresponding functions. The means may include various hardware and / or software component(s) and / or module(s), including, but not limited to a circuit, an ASIC, or processor.

[0137] The following claims are not intended to be limited to the aspects shown herein, but are to be accorded the full scope consistent with the language of the claims. Within a claim, reference to an element in the singular is not intended to mean “one and only one” unless specifically so stated, but rather “one or more.” Unless specifically stated otherwise, the term “some” refers to one or more. No claim element is to be construed under the provisions of 35 U.S.C. § 112(f) unless the element is expressly recited using the phrase “means for.” All structural and functional equivalents to the elements of the various aspects described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims.P+S Ref. No.: QUAL / 2405563PC

Claims

Qualcomm Ref. No.: 2405563WO 32WHAT IS CLAIMED IS:

1. An apparatus for energy harvesting, comprising: an energy harvesting circuit; a reconfigurable capacitor circuit coupled to an output of the energy harvesting circuit; a voltage converter having an input coupled to the output of the energy harvesting circuit; and a controller circuit having a supply input coupled to an output of the voltage converter and an output coupled to at least one control input of the reconfigurable capacitor circuit.

2. The apparatus of claim 1, wherein the voltage converter comprises a charge pump.

3. The apparatus of claim 1, wherein the reconfigurable capacitor circuit is configurable in a first configuration including parallel capacitive elements or in a second configuration including series capacitive elements.

4. The apparatus of claim 3, wherein the reconfigurable capacitor circuit is configurable in a third configuration including a first set of series capacitive elements in parallel with a second set of series capacitive elements.

5. The apparatus of claim 1, wherein: the reconfigurable capacitor circuit is configured to store an energy harvesting voltage from the energy harvesting circuit; and the controller circuit comprises a voltage sense circuit configured to sense the energy harvesting voltage and control the reconfigurable capacitor circuit based on the sensed energy harvesting voltage.

6. The apparatus of claim 5, wherein the controller circuit is configured to control one or more switches of the reconfigurable capacitor circuit.P+S Ref. No.: QUAL / 2405563PCQualcomm Ref. No.: 2405563WO 337. The apparatus of claim 6, wherein the controller circuit is configured to control the one or more switches to: configure the reconfigurable capacitor circuit with a first set of capacitive elements in parallel based on the sensed energy harvesting voltage being greater than a first threshold voltage; and configure the reconfigurable capacitor circuit with the first set of capacitive elements in series based on the sensed energy harvesting voltage being equal to or less than the first threshold voltage.

8. The apparatus of claim 7, further comprising a switch coupled between the output of the energy harvesting circuit and a load circuit, wherein the switch is configured to be closed when the sensed energy harvesting voltage is greater than a second threshold voltage, the second threshold voltage being greater than the first threshold voltage.

9. The apparatus of claim 8, wherein the switch is configured to remain closed until the sensed energy harvesting voltage is less than the first threshold voltage.

10. A method for energy harvesting, comprising: generating, via an energy harvesting circuit, an energy harvesting voltage at an output of the energy harvesting circuit; generating, via a converter, a supply voltage based on the energy harvesting voltage; and controlling, via a controller circuit, a reconfigurable capacitor circuit coupled to the output of the energy harvesting circuit using the supply voltage.

11. The method of claim 10, further comprising: storing, via the reconfigurable capacitor circuit, the energy harvesting voltage from the energy harvesting circuit; and sensing, via the controller circuit, the energy harvesting voltage, the reconfigurable capacitor circuit being controlled based on the sensed energy harvesting voltage.P+S Ref. No.: QUAL / 2405563PCQualcomm Ref. No.: 2405563WO 3412. The method of claim 10, wherein controlling the reconfigurable capacitor circuit comprises controlling one or more switches of the reconfigurable capacitor circuit.

13. The method of claim 12, wherein controlling the one or more switches comprises: configuring the reconfigurable capacitor circuit with a first set of capacitive elements in parallel based on the energy harvesting voltage being greater than a first threshold voltage; and configuring the reconfigurable capacitor circuit with the first set of capacitive elements in series based on the energy harvesting voltage being equal to or less than the first threshold voltage.

14. The method of claim 13, wherein a switch is coupled between the output of the energy harvesting circuit and a load circuit, the method further comprising closing the switch when the energy harvesting voltage at the output of the energy harvesting circuit is greater than a second threshold voltage, the second threshold voltage being greater than the first threshold voltage.

15. The method of claim 14, further comprising maintaining the switch in a closed state until the energy harvesting voltage at the output of the energy harvesting circuit is less than the first threshold voltage.

16. A wireless device, comprising: an antenna; an energy harvesting circuit coupled to the antenna; a reconfigurable capacitor circuit coupled to an output of the energy harvesting circuit; a voltage converter having an input coupled to the output of the energy harvesting circuit; and a controller circuit having a supply input coupled to an output of the voltage converter and an output coupled to at least one control input of the reconfigurable capacitor circuit.P+S Ref. No.: QUAL / 2405563PCQualcomm Ref. No.: 2405563WO 3517. The wireless device of claim 16, wherein the voltage converter comprises a charge pump.

18. The wireless device of claim 16, wherein the reconfigurable capacitor circuit is configurable in a first configuration including parallel capacitive elements or in a second configuration including series capacitive elements.

19. The wireless device of claim 18, wherein the reconfigurable capacitor circuit is configurable in a third configuration including a first set of series capacitive elements in parallel with a second set of series capacitive elements.

20. The wireless device of claim 16, wherein: the reconfigurable capacitor circuit is configured to store an energy harvesting voltage from the energy harvesting circuit; and the controller circuit comprises a voltage sense circuit configured to sense the energy harvesting voltage and control the reconfigurable capacitor circuit based on the sensed energy harvesting voltage.P+S Ref. No.: QUAL / 2405563PC

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