Physical random access channel based on frequency hopping

Abstract

Various aspects of the present disclosure generally relate to wireless communications. In some aspects, a user equipment (UE) can receive a physical random access channel (PRACH) configuration indicating a set of resources for a random access channel (RACH) preamble. The UE can receive an input radio frequency (RF) signal. The UE can select a start frequency for a frequency hopping mode for the RACH preamble. The UE can transmit the RACH preamble in the set of resources at the starting frequency and according to the frequency hopping pattern, wherein transmitting the RACH preamble includes backscatter modulation of the input RF signal. Numerous other aspects are described.

Description

Technical Field

[0001] Aspects of the present disclosure generally relate to wireless communication and relate to techniques and apparatus for physical random access channel (PRACH) transmission based on frequency hopping. Background Art

[0002] Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, broadcasting, or other similar types of services. These wireless communication systems may employ multiple access techniques capable of supporting communication with those users by sharing available wireless communication system resources with multiple users.

[0003] Although wireless communication systems have made great technological progress over the years, challenges still remain. For example, complex and dynamic environments can still attenuate or block signals between a wireless transmitter and a wireless receiver. Accordingly, there is a continuing expectation to improve the technical performance of wireless communication systems, including for example: improving the speed and data carrying capacity of communication, improving the efficiency of using the shared communication medium, reducing the power used by the transmitter and receiver when performing communication, improving the reliability of wireless communication, avoiding redundant transmission and / or reception and related processing, improving the coverage area of wireless communication, increasing the number and types of devices that can access the wireless communication system, increasing the ability of different types of devices to communicate with each other, increasing the number and types of wireless communication media available for use, etc. Therefore, there is a need to further improve wireless communication systems to overcome the foregoing technical challenges and other challenges. Summary of the Invention

[0004] Some aspects described herein relate to a method of wireless communication performed by a user equipment (UE). The method may include receiving a physical random access channel (PRACH) configuration indicating a resource set for a random access channel (RACH) preamble. The method may include receiving an input radio frequency (RF) signal. The method may include selecting a starting frequency for a frequency hopping pattern for the RACH preamble. The method may include transmitting the RACH preamble in the resource set at the starting frequency and according to the frequency hopping pattern, wherein transmitting the RACH preamble includes backscatter modulation of the input RF signal.

[0005] Some aspects described herein relate to a method of wireless communication performed by a network entity. The method may include outputting a PRACH configuration indicating a resource set for a RACH preamble. The method may include receiving the RACH preamble on the resource set at a starting frequency and according to a frequency hopping pattern, wherein transmitting includes backscatter modulation of an input RF signal.

[0006] Other aspects provide: an apparatus operable to, configured to, or otherwise adapted to perform any one or more of the aforementioned methods and / or those described herein with reference to the accompanying drawings and as illustrated in the accompanying drawings; a non-transitory computer-readable medium comprising computer-executable instructions that, when executed by a processor of the apparatus, cause the apparatus to perform the aforementioned methods and / or those described herein with reference to the accompanying drawings and as illustrated in the accompanying drawings; a computer program product embodied on a computer-readable storage medium comprising code for performing the aforementioned methods and / or those described herein with reference to the accompanying drawings and as illustrated in the accompanying drawings; and / or an apparatus comprising components for performing the aforementioned methods and / or those described herein with reference to the accompanying drawings and as illustrated in the accompanying drawings. By way of example, an apparatus may comprise a processing system, a device having a processing system, or processing systems cooperating through one or more networks.

[0007] The features and technical advantages of the examples according to the present disclosure have been outlined quite broadly above so that the following detailed description may be better understood. Additional features and advantages will be described below. The concepts and specific examples disclosed may be readily utilized as a basis for modifying or designing other structures for achieving the same purposes of the present disclosure. Such equivalent constructions do not depart from the scope of the appended claims. The characteristics of the concepts disclosed herein, both in terms of their organization and method of operation, and the associated advantages will be better understood by considering the following description in conjunction with the accompanying drawings. Each of the figures in the drawings is provided for the purpose of illustration and description and not as a definition of limitations to the claims.

[0008] While aspects are described herein by way of illustration of some examples, those skilled in the art will understand that such aspects can be implemented in many different arrangements and scenarios. The techniques described herein can be implemented using different platform types, devices, systems, shapes, sizes, and / or packaging arrangements. For example, some aspects can be implemented via an integrated chip implementation or other devices based on non-module components (e.g., end-user devices, vehicles, communication devices, computing devices, industrial equipment, retail / shopping devices, medical devices, and / or artificial intelligence devices). Aspects can be implemented in chip-level components, modular components, non-modular components, non-chip-level components, device-level components, and / or system-level components. Devices incorporating the described aspects and features can include additional components and features for implementing and practicing the claimed and described aspects. For example, the transmission and reception of wireless signals can include one or more components for analog and digital purposes (e.g., hardware components including antennas, radio frequency (RF) chains, power amplifiers, modulators, buffers, processors, interleavers, adders, and / or summers). The aspects described herein are intended to be practiced in a wide variety of devices, components, systems, distributed arrangements, and / or end-user devices of various sizes, shapes, and configurations. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] To gain a more detailed understanding of the foregoing features of the present disclosure, a more specific description of the inventive concepts briefly summarized above can be obtained by reference to aspects, some of which are illustrated in the accompanying drawings. It should be noted, however, that the drawings illustrate only certain typical aspects of the present disclosure and are therefore not to be considered limiting of its scope, as the specification may admit other equally effective aspects. The same reference numerals in different drawings may identify the same or similar elements.

[0010] Figure 1 An example of a wireless communication network according to the present disclosure is depicted.

[0011] Figure 2 Aspects of an example base station (BS) and user equipment (UE) according to the present disclosure are depicted.

[0012] Figure 3 An example of a decomposed base station architecture is depicted.

[0013] Figure 4A 、 Figure 4B 、 Figure 4C and Figure 4D Aspects of a data structure for a wireless communication network according to the present disclosure are depicted.

[0014] Figure 5 is a diagram illustrating an example of the architecture of a radio frequency (RF) energy harvesting device according to some examples.

[0015] Figure 6 FIG. is an illustration showing an example of an ultra - light IoT device.

[0016] Figure 7 FIG. is an illustration showing an example of a Physical Random Access Channel (PRACH) signal transmission using inner - layer fixed - size frequency hopping and outer - layer pseudo - random frequency hopping according to some examples.

[0017] Figure 8 FIG. is an illustration showing an example of signaling for PRACH frequency hopping for ultra - light Internet of Things (IoT) according to the present disclosure.

[0018] Figure 9 FIG. is an illustration showing an example of synchronization before transmission of a Random Access Channel (RACH) preamble using backscatter modulation according to the present disclosure.

[0019] Figure 10 FIG. is an illustration showing an example of wake - up signaling and go - to - sleep signaling for RACH preamble transmission using backscatter modulation according to the present disclosure.

[0020] Figure 11 FIG. shows a method for wireless communication by a UE.

[0021] Figure 12 FIG. shows a method for wireless communication by a network entity.

[0022] Figure 13 FIG. is an illustration showing an example of a specific implementation of code and circuitry for a communication device according to the present disclosure.

[0023] Figure 14 FIG. is an illustration showing an example of a specific implementation of code and circuitry for a communication device according to the present disclosure. DETAILED DESCRIPTION

[0024] Aspects of the present disclosure provide apparatuses, methods, processing systems, and computer - readable media for random access channel transmission.

[0025] In various wireless communication networks, various client devices that can be associated with different signaling and communication capabilities can be utilized. For example, as the 5G network expands into industrial verticals and the number of deployed Internet of Things (IoT) devices grows, network service categories such as enhanced mobile broadband (eMBB), ultra - reliable low - latency communication (URLLC), and massive machine - type communication (mMTC) can be extended to better support various IoT devices, which can include passive IoT devices, semi - passive IoT devices, ultra - light IoT devices, etc.

[0026] For example, passive IoT devices and semi-passive IoT devices are relatively low-cost user equipments (UEs) that can be used to implement one or more sensing and communication capabilities in an IoT network or deployment. In some examples, passive and / or semi-passive IoT sensors (e.g., devices) can be used to provide sensing capabilities for various processes and use cases such as asset management, logistics, warehousing, manufacturing, etc. Passive and semi-passive IoT devices can include one or more sensors, processors, or microcontrollers, and an energy harvester for generating power from incident downlink radio frequency (RF) signals received at the passive or semi-passive IoT device.

[0027] Based on harvesting energy from incident downlink RF signals (e.g., sent by network devices such as base stations, gNBs, etc.), energy harvesting devices (e.g., passive IoT devices, semi-passive IoT devices) can be provided without an energy storage element and / or can be provided with a relatively small energy storage element (e.g., battery, capacitor, etc.). Energy harvesting devices can be deployed on a large scale based on the simplification of the manufacturing and deployment of these energy harvesting devices associated with implementing wireless energy harvesting (e.g., relative to eMBB UEs).

[0028] In a wireless communication network environment (e.g., cellular network, etc.), network devices (e.g., base stations or gNBs) can be used to send downlink RF signals to energy harvesting devices. In an illustrative example, a base station or gNB can read and / or write information stored on an energy harvesting IoT device by sending a downlink RF signal. The downlink RF signal can provide energy to the energy harvesting IoT device and can be used as a basis for an information-bearing uplink signal sent back to the network device (or sent back to another receiver) by the energy harvesting IoT device (e.g., based on reflecting or backscattering a portion of the incident downlink RF signal). The base station or gNB can read the reflected signal sent by the energy harvesting IoT device to decode the information sent by the IoT device (e.g., sensor information collected by one or more sensors included in the IoT device).

[0029] In some examples, for a given downlink signal with a given input RF power received at an energy harvesting device, a first portion of the input RF power is provided to the energy harvester of the device (e.g., where a certain percentage is converted into useful power based on the conversion efficiency of the harvester, while the remaining percentage is wasted or dissipated as heat). The remaining second portion of the input RF power can be used for backscattering in an uplink transmission (e.g., the second portion of the input power is reflected and modulated for uplink communication).

[0030] The ultra-light IoT device may include both a backscatter transmitter (e.g., a backscatter radio component) and an active transmitter (e.g., an active radio component). The backscatter transmitter may generate and transmit an uplink signal by reflecting and backscattering modulating an incident downlink signal. In some examples, the ultra-light IoT device may use the same or a similar backscatter transmitter as that utilized by a passive or semi-passive IoT device. The active transmitter may use a battery or other energy storage element included in the ultra-light IoT device to generate and transmit an uplink signal. To transmit an uplink signal, the backscatter transmitter of the ultra-light IoT device must first receive a downlink signal that can be reflected and backscattered modulated. For example, the backscatter transmitter may not be able to transmit an uplink signal unless or until a continuous sine wave is received as a downlink signal from a base station, gNB, or other network device. The active transmitter of the ultra-light IoT device may perform uplink communication triggered by the ultra-light IoT device (e.g., without relying on first receiving a downlink signal).

[0031] The ultra-light IoT device may include only a small battery or energy storage element and may not use the active transmitter of the ultra-light IoT device to maintain uplink communication for a longer period. For example, active transmission by the ultra-light IoT device may quickly deplete the on-board battery or other energy storage element included in the ultra-light IoT device.

[0032] A physical random access channel (PRACH) signal and communication may be used by a UE (e.g., an ultra-light IoT device) to align the UE's uplink transmission with a base station or gNB and obtain access to a wireless network associated with the base station or gNB (e.g., connect to the wireless network). For example, the PRACH signal may be used for an initial access request from the UE to the base station and may be used to obtain time synchronization. To access the network, the UE may request access by sending a random access (RA) preamble (sometimes referred to as a PRACH preamble) via the PRACH signal. The RA preamble may be detected by a PRACH receiver at the base station, which estimates the ID of the transmitted preamble and the propagation delay between the UE and the base station. Then, time synchronization is performed between the base station and the UE according to a time alignment (TA) value sent from the base station before the uplink transmission (e.g., determined based on the propagation delay estimation).

[0033] A UE (e.g., an ultra - light IoT device) can utilize frequency hopping, which improves frequency diversity and reduces inter - cell interference. Frequency hopping can involve switching the transmission frequency of a signal from one sub - carrier to another during the transmission of the signal. The UE and the network entity can benefit from mutual knowledge of the start time and frequency of the frequency hopping and the hopping pattern of the frequency hopping. However, there are cases where a UE (e.g., an ultra - light IoT device) may not be fully (e.g., perfectly) synchronized with the network in time and frequency. For example, the UE may exit a long sleep and send a PRACH preamble before being synchronized with the network. As another example, the UE may not perform a form of synchronization (e.g., frequency synchronization and / or time synchronization). If frequency hopping does not take into account a partially synchronized configuration or an asynchronous configuration, conflicts between UEs may occur or PRACH transmission or reception may fail. If both time synchronization and frequency synchronization are required, the UE (especially an ultra - light IoT device) may consume a large amount of power and may require higher - cost components compared to the case where it does not perform one or more of time synchronization or frequency synchronization.

[0034] Some of the techniques described herein implement PRACH transmission for partially synchronized UEs or asynchronous UEs (such as ultra - light IoT devices). For example, a UE can send a RACH preamble on a set of resources configured for the UE for the transmission of a random access channel (RACH) preamble. The UE can use backscatter modulation of an input RF signal to send the RACH preamble. The UE can send the RACH preamble according to a start frequency and using a hopping pattern (e.g., the first transmission of the RACH preamble can be at the start frequency). In addition, the UE can select the start frequency. By using frequency selection, the occurrence of conflicts between UEs (which may result in the inability to receive PRACH transmissions) can be reduced. Some of the techniques described herein provide group - based wake - up signaling and / or go - to - sleep signaling to indicate available PRACH resources (compared to being fully synchronized with the network to identify available PRACH resources), which reduces the power consumption and cost of the UE.

[0035] Aspects of the present disclosure are described more fully hereinafter with reference to the accompanying drawings. However, the present disclosure may be embodied in many different forms and should not be construed as limited to any specific structure or function presented throughout this disclosure. Rather, these aspects are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the present disclosure to those skilled in the art. Those skilled in the art will appreciate that the scope of the present disclosure is intended to cover any aspect of the present disclosure disclosed herein, whether implemented independently of or in combination with any other aspect of the present disclosure. For example, any number of the aspects set forth herein may be used to implement an apparatus or practice a method. In addition, the scope of the present disclosure is intended to cover such apparatus or methods implemented using other structures, functions, or a combination of structures and functions in addition to or different from the various aspects of the present 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 the claims.

[0036] Certain aspects of a telecommunications system will now be presented with reference to various apparatuses and techniques. These apparatuses and techniques will be described in the following detailed description and illustrated in the drawings by various blocks, modules, components, circuits, steps, processes, or algorithms, etc. (collectively referred to as "elements"). These elements may be implemented using hardware, software, or a combination thereof. Whether such elements are implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system.

[0037] Although terms generally associated with 5G or new radio (NR) radio access technology (RAT) may be used herein to describe aspects, aspects of the present disclosure may be applied to other RATs such as 3G RAT, 4G RAT, and / or post-5G (e.g., 6G) RATs.

[0038] Figure 1 An example of a wireless communication network 100 in accordance with the present disclosure is depicted.

[0039] Generally speaking, the wireless communication network 100 includes various network entities (alternatively, network elements or network nodes). Network entities are typically communication devices and / or communication functions performed by communication devices (e.g., user equipment (UE), base stations (BS), components of a BS, servers, etc.). For example, the various functions of the network and the various devices associated with and interacting with the network may be considered network entities. In addition, the wireless communication network 100 includes terrestrial aspects and non-terrestrial aspects, terrestrial aspects such as terrestrial-based network entities (e.g., BS110), non-terrestrial aspects such as satellites 140 and aircraft 145, which non-terrestrial aspects may include airborne network entities (e.g., one or more BSs) capable of communicating with other network elements (e.g., terrestrial BSs) and UEs.

[0040] In the depicted example, wireless communication network 100 includes BS110, UE 120, and one or more core networks (such as evolved packet core (EPC) 160 and 5G core (5GC) 190), which interoperate to provide communication services over various communication links, including wired and wireless links.

[0041] Figure 1 Various example UEs 120 are depicted, which may include cellular phones, smart phones, session initiation protocol (SIP) phones, laptop computers, personal digital assistants (PDAs), satellite radios, global positioning systems (GPS), multimedia devices, video devices, digital audio players, cameras, game consoles, tablets, smart devices, wearable devices, vehicles, electricity meters, air pumps, kitchen appliances, healthcare devices, implants, sensors / actuators, displays, Internet of Things (IoT) devices, always-on (AON) devices, edge processing devices, or another similar device. UE 120 may also be referred to as a mobile device, wireless device, wireless communication device, station, mobile station, subscriber station, mobile subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, remote device, access terminal, mobile terminal, wireless terminal, remote terminal, or handset, among other things.

[0042] BS110 may communicate wirelessly with UE 120 via communication link 170 (e.g., send signals to or receive signals from the UE). The communication link 170 between BS110 and UE 120 may carry an uplink (UL) (also referred to as a reverse link) transmission from UE 120 to BS110 and / or a downlink (DL) (also referred to as a forward link) transmission from BS110 to UE 120. In various aspects, communication link 170 may use multiple-input multiple-output (MIMO) antenna technology, including spatial multiplexing, beamforming, and / or transmit diversity. BS110 and UE 120 may communicate with each other using RF signaling. An RF signal includes an electromagnetic wave of a given frequency that transmits information through the space between a transmitter and a receiver.

[0043] BS110 may include, for example, a NodeB, an enhanced NodeB (eNB), a next-generation enhanced NodeB (ng-eNB), a next-generation NodeB (gNB or gNodeB), an access point (AP), a transceiver base station, a radio base station, a radio transceiver, a transceiver function, a transmit receive point, and / or others. BS110 may provide communication coverage for a corresponding geographic coverage area 112, which may sometimes be referred to as a cell and which may, in some cases, overlap (e.g., a small cell provided by BS110a may have a coverage area 112' that overlaps the coverage area 112 of a macro cell). For example, BS110 may provide communication coverage for a macro cell (covering a relatively large geographic area), a pico cell (covering a relatively small geographic area, such as a stadium), a femto cell (covering a relatively small geographic area (e.g., a home)), and / or other types of cells.

[0044] Although BS110 is depicted as a single communication device in various aspects, BS110 may be implemented in various configurations. For example, one or more components of the base station may be decomposed, including a central unit (CU), one or more distributed units (DU), one or more radio units (RU), a near-real-time (near-RT) RAN intelligent controller (RIC), or a non-real-time (non-RT) RIC, to name a few examples. In another example, various aspects of the base station may be virtualized. More generally, a BS (e.g., BS110) may include components located at a single physical location or components located at various physical locations. In an example where the BS includes components located at various physical locations, the various components may each perform various functions such that the various components together achieve functions similar to those of a BS located at a single physical location. In some aspects, a BS including components located at various physical locations may be referred to as having a decomposed radio access network architecture, such as an open RAN (O-RAN) architecture or a virtualized RAN (VRAN) architecture. Figure 3 An example decomposed BS architecture is depicted and described.

[0045] The different BSs 110 within the wireless communication network 100 may also be configured to support different radio access technologies (such as 3G, 4G, and / or 5G, etc.). For example, the BS 110 configured for 4G LTE (collectively referred to as the evolved universal mobile telecommunications system (UMTS) terrestrial radio access network (E-UTRAN)) may interface with the EPC 160 via a first backhaul link 132 (e.g., the S1 interface). The BS 110 configured for 5G (e.g., 5G NR or next-generation RAN (NG-RAN)) may interface with the 5GC 190 via a second backhaul link 184. The BSs 110 may communicate with each other directly or indirectly (e.g., via the EPC 160 or 5GC 190) on a third backhaul link 134 (e.g., the X2 interface), which may be wired or wireless.

[0046] The wireless communication network 100 may subdivide the electromagnetic spectrum into various categories, frequency bands, channels, or other characteristics. In some aspects, the subdivision is based on wavelength and frequency, where frequency may also be referred to as carrier, sub-carrier, channel, tone, or sub-band. For example, 3GPP currently defines frequency range 1 (FR1) as including 410 MHz to 7125 MHz, which is commonly (interchangeably) referred to as "below 6 GHz". Similarly, 3GPP currently defines frequency range 2 (FR2) as including 24,250 MHz - 52,600 MHz, which is sometimes (interchangeably) referred to as "millimeter wave" ("mmW" or "mmWave"). A base station configured to communicate using a mmWave or near mmWave radio frequency band (e.g., a mmWave base station such as BS110b) may utilize beamforming with a UE (e.g., 120) (e.g., as shown by 182) to improve path loss and range.

[0047] The communication link 170 between the BS 110 and, for example, the UE 120 may be through one or more carriers, which may have different bandwidths (e.g., 5 MHz, 10 MHz, 15 MHz, 20 MHz, 100 MHz, 400 MHz, and / or other bandwidths) and may be aggregated in various aspects. The carriers may or may not be adjacent to each other. In some examples, the allocation of carriers may be asymmetric with respect to DL and UL (e.g., more or fewer carriers may be allocated for DL compared to UL).

[0048] Compared with communication at lower frequencies, communication using a higher frequency band may have higher path loss and shorter range. Accordingly, certain base stations (e.g., Figure 1The base station 110b) in [description] can utilize beamforming with the UE 120 to improve path loss and range, as shown at 182. For example, BS110b and UE 120 can each include multiple antennas, such as antenna elements, antenna panels, and / or antenna arrays, to facilitate beamforming. In some cases, BS110b can send beamformed signals to UE 120 in one or more transmission directions 182'. UE 120 can receive beamformed signals from BS110b in one or more reception directions 182". UE 120 can also send beamformed signals to BS110b in one or more transmission directions 182". BS110b can also receive beamformed signals from UE 120 in one or more reception directions 182'. Then, BS110b and UE 120 can perform beam training to determine the optimal reception and transmission directions for each of BS110b and UE 120. It is noted that the transmission direction and reception direction of BS110b may or may not be the same. Similarly, the transmission direction and reception direction of UE 120 may or may not be the same.

[0049] The wireless communication network 100 further includes a Wi-Fi AP 150 that communicates with a Wi-Fi station (STA) 152 via a communication link 154 in, for example, the 2.4 GHz and / or 5 GHz unlicensed spectrum.

[0050] Certain UEs 120 can communicate with each other using device-to-device (D2D) communication links 158. The D2D communication links 158 can use one or more sidelink channels, such as the Physical Sidelink Broadcast Channel (PSBCH), Physical Sidelink Discovery Channel (PSDCH), Physical Sidelink Shared Channel (PSSCH), Physical Sidelink Control Channel (PSCCH), and / or Physical Sidelink Feedback Channel (PSFCH).

[0051] The EPC 160 can include various functional components, including: a Mobility Management Entity (MME) 161, other MMEs 162, a Serving Gateway 163, a Multimedia Broadcast Multicast Service (MBMS) Gateway 164, a Broadcast Multicast Service Center (BM-SC) 165, and / or a Packet Data Network (PDN) Gateway 166, such as in the depicted example. The MME 161 can communicate with a Home Subscriber Server (HSS) 167. The MME 161 is a control node that processes the signaling between the UE 120 and the EPC 160. Generally speaking, the MME 161 provides bearer and connection management.

[0052] Generally, user Internet Protocol (IP) packets are delivered through the Serving Gateway 163, which is connected to the PDN Gateway 166. The PDN Gateway 166 provides UE IP address allocation and other functions. The PDN Gateway 166 and the BM-SC 165 are connected to the IP Service 168, 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.

[0053] The BM-SC 165 may provide functions for MBMS user service provisioning and delivery. The BM-SC 165 may serve as an entry point for content provider MBMS transmissions, 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. The MBMS Gateway 164 may distribute MBMS services to the BSs 110 belonging to a Multicast Broadcast Single Frequency Network (MBSFN) area for a particular service being broadcast, and / or may be responsible for session management (start / stop) and for collecting eMBMS-related charging information.

[0054] The 5GC 190 may include various functional components, including: an Access and Mobility Management Function (AMF) 191, other AMFs 192, a Session Management Function (SMF) 193, and a User Plane Function (UPF) 194. The AMF 191 may communicate with the Unified Data Management (UDM) 195.

[0055] The AMF 191 is a control node that processes the signaling between the UE 120 and the 5GC 190. The AMF 191 provides, for example, Quality of Service (QoS) flow and session management.

[0056] IP packets are delivered through the UPF 194, which is connected to the IP Service 196 and provides UE IP address allocation and other functions for the 5GC 190. The IP Service 196 may include, for example, the Internet, an intranet, IMS, a PS streaming service, and / or other IP services.

[0057] In various aspects, a network entity or network node may be implemented as an aggregated base station, a disaggregated base station, a component of a base station, an Integrated Access and Backhaul (IAB) node, a relay node, a sidelink node, a Transmission and Reception Point (TRP), or a combination thereof, to name a few examples.

[0058] As indicated above, Figure 1 is provided as an example. Other examples may be different from the examples described with respect to Figure 1 and are provided as examples. Other examples may be different from the examples described with respect to

[0059] Figure 2 depicts aspects of an example BS 110 and UE 120 in accordance with the present disclosure.

[0060] Generally, BS110 includes various processors (e.g., 220, 230, 238, and 240), antennas 234a - 234t (collectively 234), transceivers 232a - 232t (collectively 232) including modulators and demodulators, and other aspects that implement wireless transmission of data (e.g., data source 212) and wireless reception of data (e.g., data sink 239). For example, BS110 can transmit and receive data between BS110 and UE 120. BS110 includes a controller / processor 240 that can be configured to implement various functions described herein related to wireless communication.

[0061] Generally, UE 120 includes various processors (e.g., 258, 264, 266, and 280), antennas 252a - 252r (collectively 252), transceivers 254a - 254r (collectively 254) including modulators and demodulators, and other aspects that implement wireless transmission of data (e.g., retrieved from data source 262) and wireless reception of data (e.g., provided to data sink 260). UE 120 includes a controller / processor 280 that can be configured to implement various functions described herein related to wireless communication.

[0062] Regarding an example downlink transmission, BS110 includes a transmission processor 220 that can receive data from data source 212 and control information from controller / processor 240. The control information can be for a physical broadcast channel (PBCH), a physical control format indicator channel (PCFICH), a physical hybrid automatic repeat request (HARQ) indicator channel (PHICH), a physical downlink control channel (PDCCH), a group common PDCCH (GC PDCCH), and / or other channels. In some examples, the data can be for a physical downlink shared channel (PDSCH).

[0063] The transmission processor 220 can process (e.g., encode and symbol map) the data and control information to obtain data symbols and control symbols, respectively. The transmission processor 220 can also generate reference symbols such as for a primary synchronization signal (PSS), a secondary synchronization signal (SSS), a PBCH demodulation reference signal (DMRS), or a channel state information reference signal (CSI - RS).

[0064] The transmit (TX) multiple-input multiple-output (MIMO) processor 230 may perform spatial processing (e.g., precoding) on data symbols, control symbols, and / or reference symbols when applicable, and may provide an output symbol stream to a modulator (MOD) in the transceiver 232a - 232t. Each modulator in the transceiver 232a - 232t may process the corresponding output symbol stream to obtain an output sample stream. Each modulator may further process (e.g., convert to analog, amplify, filter, and up-convert) the output sample stream to obtain a downlink signal. The downlink signals from the modulators in the transceiver 232a - 232t may be transmitted via the antennas 234a - 234t, respectively.

[0065] The UE 120 includes antennas 252a - 252r, which may receive downlink signals from the BS110 and may provide the received signals to a demodulator (DEMOD) in the transceiver 254a - 254r, respectively. Each demodulator in the transceiver 254a - 254r may condition (e.g., filter, amplify, down-convert, and digitize) the corresponding received signal to obtain input samples. Each demodulator may further process the input samples to obtain the received symbols.

[0066] The MIMO detector 256 may obtain the received symbols from all the demodulators in the transceiver 254a - 254r, perform MIMO detection on the received symbols when applicable, and provide the detected symbols. The receive processor 258 may process (e.g., demodulate, de-interleave, and decode) the detected symbols, provide the decoded data for the UE 120 to the data sink 260, and provide the decoded control information to the controller / processor 280.

[0067] For example, for an uplink transmission, the UE 120 further includes a transmit processor 264, which may receive and process data from a data source 262 (e.g., for a physical uplink shared channel (PUSCH)) and control information from the controller / processor 280 (e.g., for a physical uplink control channel (PUCCH)). The transmit processor 264 may also generate reference symbols for a reference signal (e.g., for a sounding reference signal (SRS)). The symbols from the transmit processor 264 may be precoded by the TX MIMO processor 266 when applicable, further processed by a modulator in the transceiver 254a - 254r (e.g., for SC-FDM), and transmitted to the BS110.

[0068] At BS110, the uplink signal from UE 120 can be received by antennas 234a - 234t, processed by the demodulators in transceivers 232a - 232t, detected by the MIMO detector 236 when applicable, and further processed by the receive processor 238 to obtain the decoded data and control information transmitted by UE 120. The receive processor 238 can provide the decoded data to the data sink 239 and the decoded control information to the controller / processor 240. Memories 242 and 282 can store data and program codes (e.g., processor - executable instructions, computer - executable instructions) for BS110 and UE 120 respectively. The scheduler 244 can schedule the UE for data transmission on the downlink and / or uplink.

[0069] In various aspects, BS110 can be described as transmitting and receiving various types of data associated with the methods described herein. In these contexts, "transmitting" can refer to various mechanisms for outputting data, such as outputting data from data source 212, scheduler 244, memory 242, transmit processor 220, controller / processor 240, TX MIMO processor 230, transceivers 232a - 232t, antennas 234a - 234t, and / or other aspects described herein. Similarly, "receiving" can refer to various mechanisms for obtaining data, such as obtaining data from antennas 234a - 234t, transceivers 232a - 232t, RX MIMO detector 236, controller / processor 240, receive processor 238, scheduler 244, memory 242, network interface, and / or other aspects described herein.

[0070] In various aspects, UE 120 can similarly be described as transmitting and receiving various types of data associated with the methods described herein. In these contexts, "transmitting" can refer to various mechanisms for outputting data, such as outputting data from data source 262, memory 282, transmit processor 264, controller / processor 280, TX MIMO processor 266, transceivers 254a - 254t, antennas 252a - 252t, and / or other aspects described herein. Similarly, "receiving" can refer to various mechanisms for obtaining data, such as obtaining data from antennas 252a - 252t, transceivers 254a - 254t, RX MIMO detector 256, controller / processor 280, receive processor 258, memory 282, and / or other aspects described herein.

[0071] In some aspects, the processor can be configured to perform various operations (such as those associated with the methods described herein) and send (output) data to or receive (obtain) data from another interface configured to send or receive data respectively.

[0072] Although Figure 2 the boxes in Figure 2 are illustrated as separate components, the functions described above with respect to these boxes can be implemented in a single hardware, software, or combined component or in various combinations of components. For example, the functions described with respect to the transmit processor 264, receive processor 258, and / or TX MIMO processor 266 can be performed by or under the control of the controller / processor 280.

[0073] As indicated above, Figure 2 is provided as an example. Other examples may be different from the example described with respect to Figure 2 .

[0074] The deployment of a communication system (such as a 5G NR system) can be arranged with various components or constituent parts in a variety of ways. In a 5G NR system or network, network nodes, network entities, mobility elements of the network, RAN nodes, core network nodes, network elements, base stations, or network equipment can be implemented in a centralized architecture or a split architecture. For example, a base station (such as a Node B (NB), evolved NB (eNB), NR BS, 5G NB, access point (AP), TRP, or cell, etc.) or one or more units (or one or more components) performing base station functions can be implemented as a centralized base station (also referred to as a stand-alone base station or a monolithic base station) or a split base station. A "network entity" or "network node" can refer to a split base station or one or more units of a split base station (such as one or more CUs, one or more DUs, one or more RUs, or a combination thereof).

[0075] A centralized base station (e.g., a centralized network node) can be configured to utilize a radio protocol stack that is physically or logically integrated within a single RAN node (e.g., within a single device or unit). A split base station (e.g., a split network node) can be configured to utilize a protocol stack that is physically or logically distributed between two or more units (such as one or more CUs, one or more DUs, or one or more RUs). In some examples, a CU can be implemented within a network node, and one or more DUs can be co-located with the CU, or alternatively, can be geographically or virtually spread across one or more other network nodes. A DU can be implemented to communicate with one or more RUs. Each of the CU, DU, and RU can also be implemented as a virtual unit, such as a virtual central unit (VCU), virtual distributed unit (VDU), or virtual radio unit (VRU), etc.

[0076] Base station type operations or network design may consider the aggregation characteristics of base station functions. For example, a split base station can be utilized in an IAB network, an open radio access network (O-RAN (such as a network configuration initiated by the O-RAN Alliance)), or a virtualized radio access network (vRAN, also known as cloud radio access network (C-RAN)) to facilitate the scaling of a communication system by separating base station functions into one or more units that can be deployed separately. The split base station may include functions implemented across two or more units at various physical locations, as well as functions implemented virtually for at least one unit, which can achieve flexibility in network design. The various units of the split base station may be configured for wired or wireless communication with at least one other unit of the split base station.

[0077] Figure 3 An example split base station 300 architecture is depicted. The split base station 300 architecture may include one or more central units (CUs) 310, which may communicate directly with the core network 320 via a backhaul link, or indirectly with the core network 320 through one or more split base station units (such as a near real-time (near RT) RAN intelligent controller (RIC) 325 via an E2 link, or a non-real-time (non RT) RIC 315 associated with a service management and orchestration (SMO) framework 305, or both). The CU 310 may communicate with one or more distributed units (DUs) 330 via respective midhaul links (such as an F1 interface). The DU 330 may communicate with one or more radio units (RUs) 340 via respective fronthaul links. The RU 340 may communicate with a respective UE 120 via one or more radio frequency (RF) access links. In some specific implementations, the UE 120 may be served simultaneously by multiple RUs 340.

[0078] Each of the units (e.g., CU 310, DU 330, RU 340, and the near RT RIC 325, non-RT RIC 315, and SMO framework 305) may include one or more interfaces or be coupled to one or more interfaces that are configured to receive or transmit signals, data, or information (collectively referred to as signals) via a wired or wireless transmission medium. Each unit in the unit or the associated processor or controller that provides instructions to the communication interface of the unit may be configured to communicate with one or more of the other units via the transmission medium. For example, the units may include a wired interface that is configured to receive or transmit signals to one or more of the other units via a wired transmission medium. Additionally or alternatively, the unit may include a wireless interface that may include a receiver, a transmitter, or a transceiver (such as an RF transceiver) that is configured to receive or transmit signals or both to one or more of the other units over a wireless transmission medium.

[0079] In some aspects, the CU 310 may host one or more higher layer control functions. Such control functions may include radio resource control (RRC), packet data convergence protocol (PDCP), service data adaptation protocol (SDAP), etc. Each control function may utilize an interface that is configured to convey signals to other control functions hosted by the CU 310. The CU 310 may be configured to handle user plane functions (e.g., central unit - user plane (CU-UP)), control plane functions (e.g., central unit - control plane (CU-CP)), or a combination thereof. In some embodiments, the CU 310 may be logically split into one or more CU-UP units and one or more CU-CP units. When implemented in an O-RAN configuration, the CU-UP units may communicate bi-directionally with the CU-CP units via an interface (such as an E1 interface). As needed, the CU 310 may be implemented to communicate with the DU 330 for network control and signaling.

[0080] The DU 330 may correspond to a logical unit that includes one or more base station functions for controlling the operation of one or more RUs 340. In some aspects, the DU 330 may host one or more of the radio link control (RLC) layer, the media 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, etc.) at least partially depending on a functional split (such as the functional split defined by the 3rd Generation Partnership Project (3GPP)). In some aspects, the DU 330 may further host one or more low PHY layers. Each layer (or module) may be implemented using an interface that is configured to communicate signals with other layers (and modules) hosted by the DU 330 or with control functions hosted by the CU 310.

[0081] Lower layer functions may be implemented by one or more RUs 340. In some deployments, the RUs 340 controlled by the DU 330 may correspond to logical nodes that host 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, etc.) or both at least partially based on a functional split (such as a lower layer functional split). In such an architecture, the RUs 340 may be implemented to handle over-the-air (OTA) communication with one or more UEs 120. In some embodiments, the real-time and non-real-time aspects of control plane and user plane communication with the RUs 340 may be controlled by the corresponding DU 330. In some scenarios, this configuration may enable the implementation of the DU 330 and the CU 310 in a cloud-based RAN architecture (such as a vRAN architecture).

[0082] The SMO framework 305 can be configured to support the RAN deployment and orchestration of non-virtualized network elements and virtualized network elements. For non-virtualized network elements, the SMO framework 305 can be configured to support the deployment of dedicated physical resources for RAN coverage requirements, and these dedicated physical resources can be managed via an operation and maintenance interface (such as the O1 interface). For virtualized network elements, the SMO framework 305 can be configured to interact with a cloud computing platform (such as the Open Cloud (O-Cloud) 390) to perform network element lifecycle management (such as to instantiate virtualized network elements) via a cloud computing platform interface (such as the O2 interface). Such virtualized network elements can include, but are not limited to, the CU 310, DU 330, RU 340, and the Near RT RIC 325. In some specific implementations, the SMO framework 305 can communicate with the hardware aspect of the 4G RAN (such as the Open eNB (O-eNB) 311) via the O1 interface. Additionally, in some specific implementations, the SMO framework 305 can communicate directly with one or more RUs 340 via the O1 interface. The SMO framework 305 can also include a Non-RT RIC 315 configured to support the functions of the SMO framework 305.

[0083] The Non-RT RIC 315 can be configured to include logical functions that can enable non-real-time control and optimization of RAN elements and resources, artificial intelligence / machine learning (AI / ML) workflows including model training and updating, or policy-based guidance of applications / features in the Near RT RIC 325. The Non-RT RIC 315 can be coupled to or communicate with the Near RT RIC 325 (such as via the A1 interface). The Near RT RIC 325 can be configured to include logical functions that can enable near-real-time control and optimization of RAN elements and resources through an interface (such as via the E2 interface) via data collection and actions, and this interface connects one or more CUs 310, one or more DUs 330, or both, and the O-eNB to the Near RT RIC 325.

[0084] In some specific implementations, to generate the AI / ML models to be deployed in the near RT RIC 325, the non-RT RIC 315 may receive parameters or external enrichment information from an external server. Such information can be utilized by the near RT RIC 325 and can be received from non-network data sources or from network functions at the SMO framework 305 or the non-RT RIC 315. In some examples, the non-RT RIC 315 or the near RT RIC 325 may be configured to tune the RAN behavior or performance. For example, the non-RT RIC 315 may monitor the long-term trends and patterns of performance and employ AI / ML models to perform corrective actions via the SMO framework 305 (such as reconfiguration via O1) or via creating RAN management policies (such as A1 policies).

[0085] As indicated above, Figure 3 is provided as an example. Other examples may be different from the examples described with respect to Figure 3 described.

[0086] Figure 4A , Figure 4B , Figure 4C and Figure 4D depict aspects of data structures for a wireless communication network (such as Figure 1 wireless communication network 100) in accordance with the present disclosure. Figure 4A is a diagram 400 illustrating an example of a first subframe within a 5G (e.g., 5G NR) frame structure, Figure 4B is a diagram 430 illustrating an example of a DL channel within a 5G subframe, Figure 4C is a diagram 450 illustrating an example of a second subframe within a 5G frame structure, and Figure 4D is a diagram 480 illustrating an example of a UL channel within a 5G subframe.

[0087] A wireless communication system may utilize orthogonal frequency division multiplexing (OFDM) with a cyclic prefix (CP) on both the uplink and the downlink. Such systems may also support half-duplex operation using time division duplexing (TDD). OFDM and single carrier frequency division multiplexing (SC-FDM) divide (e.g., as depicted in Figure 4B and Figure 4D ) the system bandwidth into multiple orthogonal subcarriers. Each subcarrier can be modulated with data. Modulation symbols can be transmitted in the frequency domain using OFDM and / or in the time domain using SC-FDM.

[0088] The wireless communication frame structure can be frequency division duplexing (FDD), where for a specific set of subcarriers, the subframes within that set of subcarriers are dedicated to either DL or UL. The wireless communication frame structure can also be time division duplexing, where for a specific set of subcarriers, the subframes within that set of subcarriers are dedicated to both DL and UL.

[0089] exist Figure 4A and Figure 4C In the embodiment of the present invention, the wireless communication frame structure is TDD, where D is DL, U is UL, and F is flexibly used between DL / UL. The UE can be configured with a time slot format (dynamically configured by DL control information (DCI) or semi-statically / statically configured by RRC signaling) through a received time slot format indicator (SFI). In the depicted example, the 10ms frame is divided into 10 equally sized 1ms subframes. Each subframe may include one or more time slots. In some examples, each time slot may include 7 or 14 symbols, depending on the time slot format. The subframe may also include micro slots, which typically have fewer symbols than a whole time slot. Other wireless communication technologies may have different frame structures and / or different channels.

[0090] In certain aspects, the number of slots within a subframe is based on the slot configuration and parameter set. For example, for slot configuration 0, different parameter sets (μ) 0 through 5 allow for 1, 2, 4, 8, 16, and 32 slots per subframe, respectively. For slot configuration 1, different parameter sets 0 through 2 allow for 2, 4, and 8 slots per subframe, respectively. Accordingly, for slot configuration 0 and parameter set μ, there are 14 symbols per slot and 2 per subframe. μ time slots. The subcarrier spacing and symbol length / duration are functions of the parameter set. The subcarrier spacing can be equal to 2 μ × 15 kHz, where μ is the parameter set index, which can be selected from values 0 to 5. Thus, the subcarrier spacing for parameter set μ = 0 is 15 kHz, and the subcarrier spacing for parameter set μ = 5 is 480 kHz. Other parameter sets and subcarrier spacings can be used. The symbol length / duration is inversely related to the subcarrier spacing. Figure 4A 、 Figure 4B 、 Figure 4C and Figure 4D An example is provided for slot configuration 0 with 14 symbols per slot and parameter set μ = 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 μs.

[0091] like Figure 4A 、 Figure 4B 、 Figure 4C and Figure 4D As depicted in FIG, a resource grid can be used to represent the frame structure. Each time slot includes a resource block (RB) (also called a physical RB (PRB)) extending over, for example, 12 consecutive subcarriers. The resource grid is divided into a plurality of resource elements (REs). The number of bits carried by each RE depends on the modulation scheme.

[0092] like Figure 4AAs illustrated, some of the REs in the RE carry reference (pilot) signals (RSs) for a UE (e.g., UE 120). The RSs may include demodulation RSs (DMRSs) and / or channel state information reference signals (CSI-RSs) for channel estimation at the UE. The RSs may also include beam measurement RSs (BRSs), beam refinement RSs (BRRSs), and / or phase tracking RSs (PT-RSs).

[0093] Figure 4B Examples of various DL channels within a subframe of a frame are illustrated. The physical downlink control channel (PDCCH) carries DCI within one or more control channel elements (CCEs), each CCE including, for example, nine resource element groups (REGs), each REG including, for example, four consecutive REs in an OFDM symbol.

[0094] The primary synchronization signal (PSS) may be in symbol 2 of a particular subframe of a frame. The PSS is used by a UE (e.g., UE 120) to determine subframe / symbol timing and the physical layer identity.

[0095] The secondary synchronization signal (SSS) may be in symbol 4 of a particular subframe of a frame. The SSS is used by the UE to determine the physical layer cell identity group number and radio frame timing.

[0096] Based on the physical layer identity and the physical layer cell identity group number, the UE may determine the physical cell identifier (PCI). Based on the PCI, the UE may determine the location of the aforementioned DMRS. The physical broadcast channel (PBCH) carrying the master information block (MIB) may be logically grouped with the PSS and the SSS to form a synchronization signal (SS) / PBCH block (SSB). The MIB provides the system frame number (SFN) and the number of resource blocks (RBs) in the system bandwidth. The physical downlink shared channel (PDSCH) carries user data, broadcast system information not transmitted via the PBCH (such as system information blocks (SIBs)), and / or paging messages.

[0097] As Figure 4CAs illustrated, some of the REs in the RE carry DMRS for channel estimation at the base station (indicated as R for one specific configuration, but other DMRS configurations are possible). The UE can transmit DMRS for the physical uplink control channel (PUCCH) and DMRS for the physical uplink shared channel (PUSCH). The PUSCH DMRS can be transmitted, for example, in the previous one or two symbols of the PUSCH. The PUCCH DMRS can be transmitted in different configurations depending on whether a short PUCCH or a long PUCCH is transmitted and depending on the specific PUCCH format used. The UE 120 can transmit a sounding reference signal (SRS). The SRS can be transmitted, for example, in the last symbol of the subframe. The SRS can have a comb structure, and the UE can transmit the SRS on one of these teeth. The SRS can be used by the base station for channel quality estimation to enable frequency-dependent scheduling of the UL.

[0098] Figure 4D Examples of various UL channels within a subframe of a frame are illustrated. The PUCCH can be located at the position indicated in one configuration. The PUCCH carries uplink control information (UCI), such as a scheduling request, a channel quality indicator (CQI), a precoding matrix indicator (PMI), a rank indicator (RI), and a hybrid automatic repeat request (HARQ) acknowledgement and / or negative acknowledgement (ACK / NACK) feedback. The PUSCH carries data and can additionally be used to carry a buffer status report (BSR), a power headroom report (PHR), and / or UCI.

[0099] Figure 5 FIG. is a diagram illustrating an example of the architecture of an RF energy harvesting device 500 according to some examples. The RF energy harvesting device 500 can harvest RF energy from one or more RF signals received using the antenna 590. As used herein, the term "energy harvesting" can be used interchangeably with "power harvesting". In some aspects, the energy harvesting device 500 can be implemented as an IoT device, can be implemented as a sensor, etc., as will be described in more depth below. In other examples, the energy harvesting device 500 can be implemented as an RF identification (RFID) tag or various other RFID devices.

[0100] The energy harvesting device 500 includes one or more antennas 590 that can be used to transmit and receive one or more wireless signals. For example, the energy harvesting device 500 can use the antenna 590 to receive one or more downlink signals and transmit one or more uplink signals. The impedance matching component 510 can be used to match the impedance of the antenna 590 with the impedance of one or more (or all) receiving components included in the energy harvesting device 500. In some examples, the receiving components of the energy harvesting device 500 can include a demodulator 520 (e.g., for demodulating the received downlink signals), an energy harvester 530 (e.g., for harvesting RF energy from the received downlink signals), a regulator 540, a microcontroller unit (MCU) 550, and / or a modulator 560 (e.g., for generating uplink signals). In some cases, the receiving components of the energy harvesting device 500 can also include one or more sensors 570.

[0101] The downlink signals can be received from one or more transmitters. For example, the energy harvesting device 500 can receive downlink signals from a network node or network entity (e.g., the network node or network entity may or may not be included in the same wireless network as the energy harvesting device 500). In some cases, the network entity can be a base station, gNB, etc. that communicates with the energy harvesting device 500 using a cellular communication network. For example, the cellular communication network can be implemented according to 3G, 4G, 5G, and / or other cellular standards (e.g., including future standards such as 6G and above).

[0102] In some cases, the energy harvesting device 500 can be implemented as a passive or semi - passive energy harvesting device that performs passive uplink communication by modulating and reflecting the downlink signals received via the antenna 590. For example, passive and semi - passive energy harvesting devices may not be able to generate and transmit uplink signals without first receiving downlink signals that can be modulated and reflected. In other examples, the energy harvesting device 500 can be implemented as an active energy harvesting device that performs active uplink communication using a powered transceiver. The active energy harvesting device is capable of generating and transmitting uplink signals without first receiving a downlink signal (e.g., by using a power source on the device to power its powered transceiver).

[0103] An active or semi-passive energy harvesting device may include one or more energy storage elements 585 (e.g., collectively referred to as an “energy reservoir”). For example, the one or more energy storage elements 585 may include a battery, a capacitor, etc. In some examples, the one or more energy storage elements 585 may be associated with a boost converter 580. The boost converter 580 may receive at least a portion of the energy harvested by the energy harvester 530 as an input (e.g., the remaining portion of the harvested energy is provided as instantaneous power for operating the energy harvesting device 500). In some aspects, the boost converter 580 may be a converter that raises the voltage from its input to its output (e.g., and reduces the current from its input to its output). In some examples, the boost converter 580 may be used to raise the harvested energy generated by the energy harvester 530 to a voltage level associated with charging the one or more energy storage elements 585. An active or semi-passive energy harvesting device may include one or more energy storage elements 585 and may include one or more boost converters 580. The number of energy storage elements 585 may be the same as or different from the number of boost converters 580 included in the active or semi-passive energy harvesting device.

[0104] A passive energy harvesting device does not include an energy storage element 585 or other on-device power source. For example, a passive energy harvesting device may be powered only by RF energy harvested from a downlink signal (e.g., using the energy harvester 530). As mentioned above, a semi-passive energy harvesting device may include one or more energy storage elements 585 and / or other on-device power source. The energy storage element 585 of the semi-passive energy harvesting device may be used to augment or supplement the RF energy harvested from the downlink signal. In some cases, the energy storage element 585 of the semi-passive energy harvesting device may not store enough energy to transmit an uplink communication without first receiving a downlink communication (e.g., the minimum transmit power of the semi-passive device > the capacity of the energy storage element). An active energy harvesting device may include one or more energy storage elements 585 and / or other on-device power source, which may power an uplink communication without using supplementary harvested RF energy (e.g., the minimum transmit power of the active device < the capacity of the energy storage element). The energy storage element 585 included in an active energy harvesting device and / or a semi-passive energy harvesting device may be charged using the harvested RF energy.

[0105] As mentioned above, passive and semi-passive energy harvesting devices transmit uplink communications by performing backscatter modulation to modulate and reflect the received downlink signal. The received downlink signal is used for both providing power (e.g., performing demodulation, local processing, and modulation) and a carrier for uplink communications (e.g., reflection of the downlink signal). For example, a portion of the downlink signal can be backscattered as the uplink signal, while the remaining portion of the downlink signal can be used to perform energy harvesting.

[0106] Active energy harvesting devices can transmit uplink communications without performing backscatter modulation and without receiving a corresponding downlink signal (e.g., the active energy harvesting device includes an energy storage element for providing power and a powered transceiver for generating a carrier for uplink communications). In the absence of a downlink signal, passive and semi-passive energy harvesting devices cannot transmit uplink signals (e.g., passive communications). Active energy harvesting devices do not rely on receiving a downlink signal to transmit uplink signals and can transmit uplink signals as needed (e.g., active communications).

[0107] In some aspects, an ultra-light IoT device can include both a backscatter transmitter (e.g., backscatter radio components) and an active transmitter (e.g., active radio components). The ultra-light IoT device can also be referred to as an energy harvesting device. For example, in some cases, the ultra-light IoT device can be implemented as a combination of a passive or semi-passive energy harvesting device and an active energy harvesting device. Example ultra-light IoT devices will be described in more detail below with respect to Figure 6 Example ultra-light IoT devices will be described in more detail below with respect to

[0108] Returning to Figure 5 the discussion, in an example where the energy harvesting device 500 is implemented as a passive or semi-passive energy harvesting device, an antenna 590 can be used to receive a continuous carrier downlink signal and modulate (e.g., re-modulate) the continuous carrier downlink signal for uplink communications. In some cases, a modulator 560 can be used to modulate the reflected (e.g., backscattered) portion of the downlink signal. For example, the continuous carrier can be a continuous sine wave (e.g., sine or cosine waveform), and the modulator 560 can perform modulation based on changing one or more of the amplitude and phase of the backscattered reflection. Based on modulating the backscattered reflection, the modulator 560 can encode digital symbols (e.g., binary symbols or more complex symbol systems) indicative of uplink communications. For example, the uplink communications can indicate sensor data, control data, or other information associated with one or more sensors 570 included in the energy harvesting device 500.

[0109] As mentioned above, the impedance matching component 510 can be used to match the impedance of the antenna 590 with the receiving component of the energy harvesting device 500 when receiving a downlink signal (e.g., when receiving a continuous carrier). In some examples, during backscatter operation (e.g., when transmitting an uplink signal), modulation can be performed based on intentionally mismatching the antenna input impedance so that a portion of the incident downlink signal is scattered back. The phase and amplitude of the backscattered reflection can be determined based on the impedance load on the antenna 590. Based on changing the antenna impedance (e.g., changing the impedance mismatch between the antenna 590 and the remaining components of the energy harvesting device 500), digital symbols and / or binary information can be encoded (e.g., modulated) onto the backscattered reflection. A modulator 560 can be used to perform changing the antenna impedance to modulate the phase and / or amplitude of the backscattered reflection.

[0110] As Figure 5 Illustrated, a portion of the downlink signal received using the antenna 590 can be provided to the demodulator 520, which performs demodulation and provides the downlink communication (e.g., carried or modulated on the downlink signal) to a processor such as a microcontroller unit (MCU) 550 or another processor included in the energy harvesting device 500. The remaining portion of the downlink signal received using the antenna 590 can be provided to the energy harvester 530, which harvests RF energy from the downlink signal. For example, the energy harvester 530 can harvest RF energy based on performing AC to DC (alternating current to direct current) conversion, where an AC current is generated from the sine carrier of the downlink signal and the converted DC current is used to power the energy harvesting device 500. In some aspects, the energy harvester 530 can include one or more rectifiers for performing AC to DC conversion. The rectifier can include one or more diodes or thin film transistors (TFTs). In one illustrative example, the energy harvester 530 can include one or more Schottky diode-based rectifiers. In some cases, the energy harvester 530 can include one or more TFT-based rectifiers.

[0111] The output of the energy harvester 530 is a DC current that is generated (e.g., harvested) from a portion of the downlink signal provided to the energy harvester 530. In some aspects, the DC current output of the energy harvester 530 can vary with the input provided to the energy harvester 530. For example, an increase in the input current to the energy harvester 530 can be associated with an increase in the output DC current generated by the energy harvester 530. In some cases, the MCU 550 can be associated with a band of acceptable DC current values. The regulator 540 can be used to eliminate or otherwise reduce variations in the DC current output by the energy harvester 530. For example, the regulator 540 can eliminate or smooth out spikes (e.g., increases) in the DC current output by the energy harvester 530 (e.g., such that the DC current provided as an input to the MCU 550 by the regulator 540 remains below a first threshold). In some cases, the regulator 540 can eliminate or otherwise compensate for a decrease or reduction in the DC current output by the energy harvester 530 (e.g., such that the DC current provided as an input to the MCU 550 by the regulator 540 remains above a second threshold).

[0112] In some aspects, the harvested DC current (e.g., generated by the energy harvester 530 and up or down regulated by the regulator 540 as needed) can be used to power the MCU 550 and one or more additional components included in the energy harvesting device 500. For example, the harvested DC current can additionally be used to power one or more (or all) of the impedance matching 510, the demodulator 520, the regulator 540, the MCU 550, the sensor 570, the modulator 560, and / or other components of the energy harvesting device 500. For example, the sensor 570 and the modulator 560 can receive at least a portion of the harvested DC current remaining after the MCU 550 (e.g., not consumed by the MCU 550). In some cases, the harvested DC current output by the regulator 540 can be provided to the MCU 550, the modulator 560, and the sensor 570 in series, in parallel, or a combination thereof.

[0113] In some examples, sensor 570 can be used to obtain sensor data (e.g., sensor data associated with the environment in which energy harvesting device 500 is located). Sensor 570 can include one or more sensors, which can be of the same type or different types. In some aspects, one or more (or all) of the sensors in sensor 570 can be configured to obtain sensor data based on control information included in the downlink signal received using antenna 590. For example, one or more of the sensors in sensor 570 can be configured based on downlink communication obtained by demodulating the received downlink signal using demodulator 520. In an illustrative example, sensor data can be transmitted based on modulating the backscatter reflection (e.g., changing one or more of its amplitude and / or phase) of a continuous carrier received at antenna 590 using modulator 560. Based on modulating the backscatter reflection, modulator 560 can encode digital symbols (e.g., binary symbols or more complex symbol systems) indicative of uplink communication or data messages. In some examples, modulator 560 can generate an uplink backscatter modulation signal based on directly receiving sensor data from sensor 570. In some examples, modulator 560 can generate an uplink backscatter modulation signal based on sensor data received from MCU 550 (e.g., based on MCU 550 directly receiving sensor data from sensor 570).

[0114] As indicated above, Figure 5 is provided as an example. Other examples may be different from the examples described with respect to Figure 5 those described.

[0115] Figure 6 is a diagram illustrating an example of ultra-light IoT device 600. Ultra-light IoT device 600 can include energy harvester 630, which can be used to harvest energy from one or more downlink energy signals (e.g., RF signals) received as input. In some examples, energy harvester 630 can be the same as or similar to the energy harvester 530 illustrated in Figure 5 In some cases, energy harvester 630 can include one or more components of the components included in the energy harvesting device 500 illustrated in Figure 5 For example, energy harvester 630 can include one or more (or all) of energy harvester 530, regulator 540, boost converter 580, energy storage element 585, etc.

[0116] As mentioned above, an ultra-light IoT device (e.g., ultra-light IoT device 600) may include both a backscatter transmitter (e.g., a backscatter radio component) and an active transmitter (e.g., an active radio component). For example, ultra-light IoT device 600 includes a backscatter transmitter 660 and an active transmitter 670. In one illustrative example, the backscatter transmitter 660 may generate and transmit an uplink signal by reflecting and backscattering modulating an incident downlink signal (e.g., received at the energy harvester 630 and subsequently provided to the backscatter transmitter 660). The backscatter transmitter 660 may include Figure 5 one or more (or all) of a demodulator 520, a modulator 560, an antenna 590, an MCU 550, etc., as illustrated by the energy harvesting device 500.

[0117] The active transmitter 670 may use a battery or other energy storage element included in the ultra-light IoT device 600 (e.g., the same or similar to the energy storage element 585 illustrated by Figure 5 to generate and transmit an uplink signal. For example, the ultra-light IoT device 600 may include a battery or other energy storage element, the energy harvester 630 may include a battery or other energy storage element, and / or the active transmitter 670 may include a battery or other energy storage element, etc.

[0118] To transmit an uplink signal, the backscatter transmitter 660 may first receive a downlink signal that can be reflected and backscattered modulated. In some aspects, the uplink communication performed using the backscatter transmitter 660 may be referred to as "reader-initiated" communication (e.g., based on the backscatter transmitter 660 receiving a downlink RF signal from a network device, a base station, a gNB, or other "reader"). To use the active transmitter 670 to transmit an uplink signal, the ultra-light IoT device 600 does not need to receive a corresponding downlink RF signal. The ultra-light IoT device 600 may use the active transmitter 670 to perform uplink communication triggered by the ultra-light IoT device 600 (e.g., in an example where the ultra-light IoT device 600 is implemented as a tag, also referred to as "device-initiated" communication or "tag-initiated" communication).

[0119] In some examples, the energy harvester 630 can supply power (e.g., electrical energy or current) to the ultra - light IoT device 600 based on performing energy harvesting and / or using one or more batteries or energy storage elements. In an illustrative example, the ultra - light IoT device 600 can utilize the active transmitter 670 (e.g., along with the stored energy from the battery or energy storage element) to perform device - initiated communication with a network node (e.g., a base station, a gNB). In some cases, the device - initiated communication can include or indicate an uplink (UL) trigger for communication scheduling and / or for energy scheduling. For example, the active transmitter 670 can be used to perform device - initiated communication with a network node to request immediate scheduling or execution of energy transmission, to request one or more modifications or updates to the energy signal sent from the network node to the ultra - light IoT device 600, etc. In some cases, the active transmitter 670 can be used to perform device - initiated communication with a network node to schedule one or more communications between the ultra - light IoT device 600 and the network node.

[0120] In an illustrative example, the ultra - light IoT device 600 can use the active transmitter 670 to schedule upcoming backscatter modulation communication performed by the ultra - light IoT device 600. For example, based on the communication scheduling information sent via the active transmitter 670 of the ultra - light IoT device 600, the network node can then send a downlink RF signal to the ultra - light IoT device 600 at the scheduled time (e.g., using one or more scheduled time - frequency resources). By using the active transmitter 670 to request a downlink RF signal from the network node at a future time, the ultra - light IoT device 600 can then use the backscatter transmitter 660 to perform the scheduled communication with the network node.

[0121] In some aspects, the ultra - light IoT device 600 can perform backscattering with frequency shift and / or can perform backscattering without frequency shift. For example, backscattering without frequency shift can be performed based on performing amplitude - shift keying (ASK) modulation and / or phase - shift keying (PSK) modulation of the reflected (e.g., backscattered) downlink RF signal using the backscatter transmitter 660 (e.g., and a modulator included in or associated with the backscatter transmitter 660). In some cases, backscattering without frequency shift can be associated with self - interference. For example, the backscatter modulation signal and the corresponding downlink RF signal used to generate the backscatter modulation signal are transmitted and received at the same frequency or frequency band, respectively. The backscatter modulation signal and the corresponding downlink RF signal also partially or fully overlap in time (e.g., because the backscatter modulation signal is generated and transmitted only when the corresponding downlink RF signal is received at the ultra - light IoT device 600).

[0122] In an illustrative example, the ultra - light IoT device 600 may perform backscattering with one or more frequency shifts. In some aspects, one or more frequency shifts may be used to implement additional modulation schemes (e.g., modulation schemes other than ASK or PSK) at the backscatter transmitter 660. In some cases, implementing frequency shifts and / or additional modulation schemes may be associated with increased complexity and / or energy consumption at the ultra - light IoT device 600. For example, a larger frequency shift (e.g., a larger Δf) may be associated with a larger energy consumption compared to a smaller frequency shift (e.g., a smaller Δf) or no frequency shift (e.g., zero Δf).

[0123] In some aspects, one or more square waves (e.g., or multiple parts of a square wave) may be used to implement backscatter frequency shifts. For example, the ultra - light IoT device 600 (e.g., and / or other UEs including the backscatter transmitter) may use one or more square waves to frequency - shift a backscatter signal (e.g., a reflected downlink RF signal). In an illustrative example, for an incoming signal S including multiple symbols in , the ultra - light IoT device 600 may perform a frequency shift based on combining the symbols included in the incoming signal S including multiple symbols in , or the ultra - light IoT device 600 may perform a frequency shift based on combining the symbols to be included in the incoming signal S in with a corresponding or respective square wave (e.g., or a part of that square wave). For example, the incoming symbol S in,0 may be combined with (square wave) 0, the incoming symbol S in,1 may be combined with (square wave) 1... and the incoming symbol S in,n may be combined with (square wave) n . In some cases, the Fourier approximation of the square - wave function square(t) used to implement the backscatter frequency shift f shift may be given as:

[0124]

[0125] As mentioned above, a UE (e.g., the ultra - light IoT device 600) can use PRACH signals and communication to align the uplink transmission of the UE with a base station or gNB, and obtain access to the wireless network associated with the base station or gNB (e.g., connect to the wireless network), or perform other types of operations. For example, the PRACH signal can be used for an initial access request from the UE to the base station and can be used to obtain time synchronization. To access the network, the UE can request access by transmitting a random access preamble via the PRACH signal. The RA preamble can be detected by a PRACH receiver at the base station, which estimates the ID of the transmitted preamble and the propagation delay between the UE and the base station. Then, the base station and the UE are time - synchronized according to the time alignment value (e.g., determined based on the propagation delay estimate) sent from the base station before the uplink transmission.

[0126] Based on the PRACH configuration information received from a network node (e.g., using the active transmitter 670 and / or using the backscatter transmitter 660), the ultra - light IoT device 600 can transmit a PRACH signal to the network node using one or more determined or selected time - frequency resources by backscatter - modulating the PRACH signal onto the reflected downlink RF signal received from the network node using the backscatter transmitter 660.

[0127] In some aspects, frequency hopping can be used to transmit the backscatter - modulated PRACH signal. For example, the ultra - light IoT device 600 can use one or more frequency - hopping patterns to transmit the backscatter - modulated PRACH signal, as will be described in more depth below.

[0128] As indicated above, Figure 6 is provided as an example. Other examples may be different from the examples described with respect to Figure 6 what is described.

[0129] Figure 7 is a diagram illustrating an example PRACH signal transmission using inner - layer fixed - size frequency hopping and outer - layer pseudo - random frequency hopping according to some examples. The time - frequency grid 700 includes a plurality of time - frequency resources that can be used for (e.g., are available for) PRACH transmission. As shown, the vertical axis of the time - frequency grid 700 corresponds to frequency (e.g., different frequency resources), and the horizontal axis of the time - frequency grid 700 corresponds to time (e.g., different time resources). Each box within the 12×7 time - frequency grid 700 can be used to transmit a symbol group. In some aspects, each symbol group can include a cyclic prefix (CP) and five symbols.

[0130] In Figure 7In the example of, a frequency hopping pattern involving multiple groups among four consecutive symbol groups can be used to implement PRACH frequency hopping. For example, the first group 710 includes symbol groups 712, 714, 716, and 718; the second group 720 includes symbol groups 722, 724, 726, and 728; and the third group 730 includes symbol groups 732, 734, 736, and 738. Inner-layer fixed-size frequency hopping can be performed by using one or more (e.g., fixed) frequency hopping steps within each of the three groups 710, 720, 730. For example, Figure 7 The inner-layer fixed-size frequency hopping pattern depicted in is based on a first-level single-subcarrier hop between the first and second symbol groups and between the third and fourth symbol groups included in each of the three groups 710, 720, 730, and a second-level six-subcarrier hop between the second and third symbol groups included in each of the three groups 710, 720, 730.

[0131] For example, with respect to the first group 710, the first-level single-subcarrier hop (e.g., with a hop step of one) is performed between the first symbol group 712 and the second symbol group 714, and is also performed between the third symbol group 716 and the fourth symbol group 718. The second-level six-subcarrier hop is performed between the second symbol group 714 and the third symbol group 716.

[0132] In some aspects, the two first-level single-subcarrier hops can be mirrored or inverted relative to each other. For example, if the first single-subcarrier hop (e.g., from the first symbol group 712 to the second symbol group 714) is a frequency hop up, the second single-subcarrier hop (e.g., from the third symbol group 716 to the fourth symbol group 718) can be in the opposite direction (e.g., a frequency hop down). If the first single-subcarrier hop is a frequency hop down, the second single-subcarrier hop can be a frequency hop up. In some examples, the mirroring or inversion of the directions of the first single-subcarrier hop and the second single-subcarrier hop can be performed based on cell coverage requirements. For example, the first-level hop can be used to ensure cell coverage, and the mirroring of the hop can be used to compensate for frequency carrier offset. In some cases, the alternation of the up single-subcarrier hop and the down single-subcarrier hop can extend across the grouping of symbol groups. For example, if the first group 710 is associated with an "up" single-subcarrier hop and a "down" single-subcarrier hop, the second group 720 can be associated with an "up" single-subcarrier hop and a "down" single-subcarrier hop, the third group 730 can be associated with an "up" single-subcarrier hop and a "down" single-subcarrier hop, and so on.

[0133] A second - level six - subcarrier hop (e.g., from the second symbol group 714 to the third symbol group 716) can be used to improve timing - estimation accuracy. In some cases, for a given two - consecutive packets of four symbol groups (e.g., between group 710 and group 720, between group 720 and group 730, etc.), the second - level six - subcarrier hop can be mirrored or reversed in direction. For example, the second - level six - subcarrier hop between the second symbol group 714 and the third symbol group 716 included in the first packet 710 is a frequency up - hop. The second - level six - subcarrier hop between the second symbol group 724 and the third symbol group 726 included in the second packet 720 can be in the opposite direction (e.g., a frequency down - hop). The second - level six - subcarrier hop between the second symbol group 734 and the third symbol group 736 included in the third packet 730 can also be in the opposite or reverse direction (e.g., a frequency up - hop).

[0134] In some examples, an outer - layer pseudo - random hop - step can be applied between consecutive groups of the four symbol groups (e.g., between group 710 and group 720, between group 720 and group 730, etc.). In an illustrative example, an outer - layer pseudo - random hop - step can be applied between the last group (e.g., the fourth symbol group) included in a given packet and the first group (e.g., the first symbol group) included in the next packet. For example, an outer - layer pseudo - random hop can be performed between the fourth symbol group 718 included in the first packet 710 and the first symbol group 722 included in the second packet 720, and an outer - layer pseudo - random hop can be performed between the fourth symbol group 728 included in the second packet 720 and the first symbol group 732 included in the third packet 730, and so on. In some examples, the outer - layer pseudo - random hop can have a pseudo - random hop - step and a pseudo - random hop - direction. For example, between the first packet 710 and the second packet 720, the pseudo - random hop can have a step of five and a direction of "up". Between the second packet 720 and the third packet 730, the pseudo - random hop can have a step of two and a direction of "down".

[0135] In some examples, each hop - step associated with PRACH signal transmission (e.g., Figure 7 the transmission illustrated by the example of

[0136] s(t)=sin(2πf i t)Rect(t) Equation (2)

[0137] S(f)=F(s(t))=sinc(f - f i ) - sinc(f + f i ) Equation (3)

[0138] Here, s(t) is the time-domain representation of the backscatter signal transmitted by an ultra-light IoT device (e.g., or other UEs with a backscatter transmitter). The sin(2πf i t) term in Equation (2) represents the continuous-wave downlink signal received at the ultra-light IoT device. Rect(t) represents a square wave or square wave function applied to frequency-shift the continuous-wave downlink signal. In Equation (3), S(f) is the frequency-domain representation of s(t) based on the Fourier transform F(s(t)).

[0139] For a signal duration τ, the bandwidth of S(f) is 2 / τ. In some cases, the time delay can be reduced by selecting the minimum frequency interval based on the duration τ. For example, if the duration τ is less than or equal to one millisecond, the minimum hopping frequency interval can be Δf hop,min > 2 kHz to minimize or eliminate inter-carrier interference. In some aspects, when using multi-hopping, the minimum frequency interval can be reduced.

[0140] As indicated above, Figure 7 is provided as an example. Other examples may be different from the examples described with respect to Figure 7 .

[0141] Figure 8 FIG. 800 is a diagram illustrating an example 800 of signaling for PRACH hopping for ultra-light IoT according to the present disclosure. Example 800 includes a UE (e.g., UE 120, energy harvesting device 500, ultra-light IoT device 600) and a network entity (e.g., BS 110, CU 310, DU 330, RU 340).

[0142] As indicated by reference numeral 805, the network entity may output (e.g., transmit or provide to another network entity for transmission) a PRACH configuration, and the UE may receive the PRACH configuration. For example, the network entity may use RRC signaling, MAC signaling, DCI, or a combination thereof to provide the PRACH configuration. In some aspects, the PRACH configuration may include information related to the transmission of a RACH preamble (such as the transmission of a RACH preamble using frequency hopping, parameters for a frequency hopping pattern, and / or the transmission of a RACH preamble by an ultra-light IoT device).

[0143] In some aspects, a resource set may define a window in which a UE may transmit a RACH preamble (e.g., a time resource set, a time and frequency (time-frequency or time-frequency) resource set, or a frequency resource set). A hopping pattern may indicate a pattern of resources (e.g., time slots, symbols, subcarriers, RACH resources) within the window on which the UE may transmit a RACH preamble. In some aspects, a network entity may indicate a common window (e.g., a common RACH resource) for all UEs (e.g., all ultra-light IoT devices, all UEs covered by the network entity). In some other aspects, the network entity may configure different windows for different UEs. For example, the network entity may divide a resource grid (e.g., a frequency grid, a time / frequency grid) into multiple subsets, and configure different subsets of the frequency grid for different UEs.

[0144] In some aspects, the resource set includes a frequency resource set for RACH preambles. For example (e.g., in a case where the UE synchronizes with the network entity before transmitting a RACH preamble), the network entity may configure the frequency resources for RACH preambles. In this case, RACH preamble transmission may conflict with data transmission. To avoid conflicts, the network entity may avoid scheduling data in a frequency range that overlaps with the frequency resources configured for RACH preamble transmission.

[0145] In some aspects, the resource set includes a time-frequency resource set for RACH preambles. For example, (e.g., in a case where the UE synchronizes with the network entity before transmitting a RACH preamble), the network entity may configure the time-frequency resources for RACH preambles (e.g., both frequency resources and duration). In some aspects, the PRACH configuration may indicate a time gap between the reception of the synchronization signal and the time-frequency resource set, as described below in conjunction with Figure 9 as described.

[0146] In some aspects, the resource set may include predefined resources. For example (e.g., in a case where the UE does not perform synchronization with the network entity, such as after waking up from a dormant state such as a long sleep), the resource set may be defined by a wireless communication specification (e.g., before establishing an RRC configuration or receiving a wake-up signal or other signaling from the network entity), which reduces overhead and processing and eliminates the need to perform synchronization to locate the resource set.

[0147] In some aspects, a PRACH configuration or a configuration received separately from the PRACH configuration or other signaling may indicate one or more parameters for a wake-up signal (e.g., a group-based wake-up signal) or a go-to-sleep signal (e.g., a group-based go-to-sleep signal). A wake-up signal is a signal that indicates a set of resources for the transmission of RACH preambles, such as based on a configuration indicating the time and / or frequency relationship between the wake-up signal and the set of resources. A go-to-sleep signal is a signal that indicates that a set of resources is not available for RACH preamble transmission, indicates the end of a set of resources for RACH preamble transmission, or indicates the stop of RACH preamble transmission. The use of one or more of the wake-up signal or the go-to-sleep signal may indicate available (or unavailable) PRACH resources, which may reduce the power consumption and processing overhead of the UE. Additionally, the use of the wake-up signal or the go-to-sleep signal may enable the identification of a set of resources for RACH preamble transmission without performing synchronization, thereby reducing the overhead and latency associated with RACH preamble transmission. In combination with Figure 10 The wake-up signal and the go-to-sleep signal are described in more detail.

[0148] As mentioned, in some aspects, a PRACH configuration or other signaling may indicate one or more parameters for the wake-up signal, including at least one of the following: the periodicity of the wake-up signal, the frequency location of the wake-up signal, or the duration of a time window for the transmission of RACH preambles (e.g., the duration of the set of resources indicated by the PRACH configuration). Additionally or alternatively, the PRACH configuration may indicate one or more parameters for the go-to-sleep signal, which may include at least one of the following: the periodicity of the go-to-sleep signal, the frequency location of the go-to-sleep signal, or the duration of a time window during which the transmission of RACH preambles is prohibited. In some other aspects, one or more parameters of the wake-up signal or the go-to-sleep signal (such as one or more of the parameters described as being configured above) may be pre-configured (e.g., indicated in a wireless communication specification).

[0149] In some aspects, a synchronization signal (e.g., Figure 9 the synchronization signal) may indicate a set of resources for RACH preambles. For example, the synchronization signal may include information indicating the set of resources. The UE may receive the synchronization signal before entering the sleep state. Thus, in some examples, the timing and frequency information at the UE may drift during the sleep state. The UE may transmit a RACH preamble after exiting the sleep state.

[0150] In some aspects, the UE may perform continuous frequency hopping such that the resource set on which the RACH preamble is transmitted includes a set of contiguous time resources (e.g., there is no time gap between the transitions of the frequency hopping pattern). Continuous frequency hopping may reduce the latency and resource usage of RACH transmissions and may be beneficial for UEs with threshold clock stability and that can switch the transmission frequency fast enough to perform continuous frequency hopping. In some aspects, the UE may perform continuous frequency hopping at least in part based on the UE having threshold clock stability and being able to switch the transmission frequency fast enough to perform continuous frequency hopping.

[0151] In some aspects, the UE may perform frequency hopping with a time gap between transitions. For example, the frequency hopping pattern (or PRACH configuration) may indicate the time gap between transitions of the frequency hopping pattern. In this example, the resource set may include a first time resource and a second time resource that is separated in time from the first time resource. The time gap may provide the UE with time to switch frequencies (e.g., warm-up duration), which may enable frequency switching for UEs that are unable to perform continuous frequency hopping due to limitations in the UE's frequency switching capabilities. Additionally, the time gap may reduce collisions between RACH preamble transmissions of different UEs that may (e.g., due to having low clock stability) have different local clock times, thereby reducing inter-UE interference.

[0152] In some aspects, the PRACH configuration indicates the length of the frequency hopping pattern. For example, a network entity may configure different UEs (e.g., different groups of UEs) to have different lengths for the frequency hopping pattern (e.g., Figure 7 for the frequency hopping pattern). A frequency hopping pattern with a larger length may have longer individual hops. By configuring different lengths of the frequency hopping pattern, the network entity may distinguish which UE is transmitting the RACH preamble based on the length of the frequency hopping of the RACH preamble. In one example, a higher priority group of UEs may be configured with a longer frequency hopping pattern, while a lower priority group of UEs may be configured with a shorter frequency hopping pattern. Thus, the length of the frequency hopping pattern is associated with the group (e.g., UE group) indicated by the PRACH configuration.

[0153] As indicated by reference numeral 810, in some examples, a network entity may transmit a synchronization signal or cause the transmission of a synchronization signal, and the UE may receive the synchronization signal. Synchronization signals are described in more detail Figure 9 below.

[0154] As indicated by reference numeral 815, in some examples, a network entity may transmit a wake-up signal or cause the transmission of a wake-up signal, and the UE may receive the wake-up signal. Wake-up signals are described in more detail Figure 10 below.

[0155] As indicated by reference numeral 820, a network entity may transmit an input RF signal or cause the transmission of an input RF signal, and the UE may receive the input RF signal. The input RF signal may include a signal from which the UE may harvest energy for the transmission of a RACH preamble.

[0156] As indicated by reference numeral 825, the UE may select a starting frequency for a frequency hopping pattern for the transmission of a RACH preamble. For example, the frequency hopping pattern may be defined relative to the starting frequency such that the UE's transmission of the RACH preamble hops from a first resource at the starting frequency to a second resource at a frequency offset defined relative to the starting frequency of the first resource. In Figure 7 this case, the starting resource is shown by symbol group 712.

[0157] In some aspects, the UE may select the starting frequency at least in part based on a random function or a hash. For example, the hash may use the UE's identifier as an input. Selecting at least in part based on a random function or a hash may save UE resources that would otherwise be used for sensing the frequency grid.

[0158] In some aspects, the UE may perform sensing of multiple frequencies. For example, the UE may sense the frequencies of a frequency grid (such as time - frequency grid 700). The frequencies may include, for example, a set of sub - carriers of a resource set indicated by a PRACH configuration. The sensing may include, for example, determining measurement values (e.g., reference signal received power, signal - to - interference - plus - noise ratio (SINR), etc.). The UE may select the starting frequency at least in part based on the sensing, as described below. In some aspects, the UE may sense each frequency of the frequency grid. For example, the UE may sense each sub - carrier included in the resource set and may select the starting frequency as the sub - carrier having the most favorable measurement value (e.g., a measurement value indicating that the sub - carrier is associated with low interference (such as the lowest SINR)) or a sub - carrier having a measurement value that meets a threshold. For example, the UE may select the starting frequency at least in part based on the starting frequency having the lowest interference value among the interference values of multiple frequencies. As another example, the UE may select the starting frequency from starting frequencies having interference values below a threshold (e.g., randomly, according to a rule). In this example, the UE may select the starting frequency at least in part based on the threshold and the interference value.

[0159] In some aspects, the UE may select the starting frequency at least in part based on a group indicated by a PRACH configuration. For example, UE groups may be mapped to starting frequencies in a resource set by the PRACH configuration. Different UE groups may be mapped to different starting frequencies.

[0160] As indicated by reference numeral 830, a UE may transmit a RACH preamble, and a network entity may obtain (e.g., receive from the UE, receive from another network entity) the RACH preamble. The transmission of the RACH preamble by the UE may be according to a frequency hopping pattern. For example, the transmission of the RACH preamble by the UE may occupy time and frequency resources defined by the frequency hopping pattern. Additionally, the transmission of the RACH preamble by the UE may be at a starting frequency. For example, the starting frequency may be used to initiate the frequency hopping pattern, and the frequency hopping pattern may identify time resources and / or frequency resources for one or more frequency hops after the initial transmission of the frequency hopping pattern. The UE may transmit the initial transmission and one or more frequency hops as indicated by the frequency hopping pattern. For example, the UE may use the energy collected from an input RF signal to perform backscatter modulation to transmit the RACH preamble.

[0161] As indicated by reference numeral 835, in some examples, a network entity may transmit a go-to-sleep signal or cause the transmission of a go-to-sleep signal, and the UE may receive the go-to-sleep signal. In connection with Figure 10 the go-to-sleep signal is described in more detail.

[0162] As indicated above, Figure 8 is provided as an example. Other examples may be different from the examples described with respect to Figure 8 that.

[0163] Figure 9 FIG. 900 is a diagram illustrating an example 900 of synchronization prior to the transmission of a RACH preamble using backscatter modulation in accordance with the present disclosure. In example 900, a network entity may transmit a synchronization signal 905 or cause the transmission of the synchronization signal, and the UE may receive the synchronization signal. The UE may use the synchronization signal 905 to synchronize with the network entity. For example, the UE may derive the clock timing of the UE from the synchronization signal 905. Additionally or alternatively, the UE may synchronize (e.g., synchronize a local oscillator) to a transmit and / or receive frequency derived from the synchronization signal 905. The synchronization signal 905 may include any form of signal. As indicated by reference numeral 910, in some aspects, the UE may identify a resource set 915 for the RACH preamble based at least in part on a time gap (T) between the synchronization signal 905 and the resource set 915. In some aspects, the PRACH configuration of the UE may indicate the time gap.

[0164] As indicated above, Figure 9 is provided as an example. Other examples may be different from the examples described with respect to Figure 9 that.

[0165] Figure 10 FIGS. 1000, 1005, and 1010 are diagrams illustrating wake-up signaling and go-to-sleep signaling for the transmission of a RACH preamble using backscatter modulation in accordance with the present disclosure.

[0166] In Example 1000, the UE receives a Wake-Up Signal (WUS) before transmitting a RACH preamble. The UE may receive the WUS based on one or more parameters of the WUS, such as the periodicity and / or frequency position of the WUS. In some aspects, the WUS may be a group-based WUS for a group of UEs including the UE. In some aspects, the UE may identify a set of resources (shown as "configured time window") for RACH preamble transmission based on the WUS. For example, the parameter may indicate the length of the set of resources corresponding to the WUS. Thus, the time window (i.e., the set of resources) may be associated with the WUS. In Example 1005, the UE receives a Go-to-Sleep Signal (GTS). The GTS may indicate a set of resources on which RACH preamble transmission is prohibited (e.g., not allowed, not permitted, pre-empted, excluded). Thus, the UE may refrain from transmitting a RACH preamble during the set of resources. In some aspects, the UE may receive the GTS based at least in part on one or more parameters configured for the GTS, such as periodicity and / or frequency position. In some aspects, the length of the set of resources on which RACH preamble transmission is performed may be indicated by a parameter, as described elsewhere herein. In Example 1010, the UE receives both the WUS (as in Example 1000) and the GTS (as in Example 1005).

[0167] As indicated above, Figure 10 is provided as an example. Other examples may be different from the examples described with respect to Figure 10 .

[0168] Figure 11 FIG. 1100 illustrates a method for wireless communication by a UE, such as UE 120.

[0169] Method 1100 begins at 1110, receiving a Physical Random Access Channel (PRACH) configuration indicating a set of resources for a Random Access Channel (RACH) preamble.

[0170] Method 1100 then proceeds to step 1120, receiving an input Radio Frequency (RF) signal.

[0171] Method 1100 then proceeds to step 1130, selecting a starting frequency for a frequency hopping pattern for the RACH preamble.

[0172] Method 1100 then proceeds to step 1140, transmitting a RACH preamble in the set of resources at the starting frequency and according to the frequency hopping pattern, wherein transmitting the RACH preamble includes backscatter modulation of the input RF signal.

[0173] In a first aspect, the set of resources includes a set of frequency resources for the RACH preamble.

[0174] In a second aspect, alone or in combination with the first aspect, the resource set includes a time-frequency resource set for RACH preambles.

[0175] In a third aspect, alone or in combination with one or more of the first and second aspects, the PRACH configuration indicates a time gap between the reception of the synchronization signal and the time-frequency resource set.

[0176] In a fourth aspect, alone or in combination with one or more of the first to third aspects, the resource set includes predefined resources.

[0177] In a fifth aspect, alone or in combination with one or more of the first to fourth aspects, method 1100 includes receiving a wake-up signal before transmitting a RACH preamble, wherein transmitting the RACH preamble includes transmitting the RACH preamble at least partially based on the wake-up signal.

[0178] In a sixth aspect, alone or in combination with one or more of the first to fifth aspects, the PRACH configuration indicates one or more parameters for the wake-up signal.

[0179] In a seventh aspect, alone or in combination with one or more of the first to sixth aspects, the one or more parameters include at least one of the following: the periodicity of the wake-up signal, the frequency position of the wake-up signal, or the duration of the time window for transmitting the RACH preamble.

[0180] In an eighth aspect, alone or in combination with one or more of the first to seventh aspects, transmitting the RACH preamble at least partially based on the wake-up signal further includes transmitting the RACH preamble in a time window associated with the wake-up signal.

[0181] In a ninth aspect, alone or in combination with one or more of the first to eighth aspects, method 1100 includes receiving a sleep entry signal and suppressing the transmission of the RACH preamble during a time period associated with the sleep entry signal.

[0182] In a tenth aspect, alone or in combination with one or more of the first to ninth aspects, the PRACH configuration indicates one or more parameters for the sleep entry signal.

[0183] In an eleventh aspect, alone or in combination with one or more of the first to tenth aspects, the one or more parameters include at least one of the following: the periodicity of the sleep entry signal, the frequency position of the sleep entry signal, or the duration of the time window for transmitting the RACH preamble.

[0184] In a twelfth aspect, either alone or in combination with one or more of the first to eleventh aspects, receiving a PRACH configuration further includes receiving the PRACH configuration before entering the sleep mode, and transmitting a RACH preamble further includes transmitting the RACH preamble after exiting the sleep mode.

[0185] In a thirteenth aspect, either alone or in combination with one or more of the first to twelfth aspects, selecting a starting frequency includes selecting the starting frequency at least in part based on a random function or a hash.

[0186] In a fourteenth aspect, either alone or in combination with one or more of the first to thirteenth aspects, method 1100 includes selecting the starting frequency at least in part based on sensing.

[0187] In a fifteenth aspect, either alone or in combination with one or more of the first to fourteenth aspects, selecting the starting frequency at least in part based on sensing further includes selecting the starting frequency according to an interference threshold.

[0188] In a sixteenth aspect, either alone or in combination with one or more of the first to fifteenth aspects, selecting the starting frequency at least in part based on sensing further includes selecting the starting frequency at least in part based on the lowest interference value among the interference values of multiple frequencies of the starting frequency.

[0189] In a seventeenth aspect, either alone or in combination with one or more of the first to sixteenth aspects, selecting the starting frequency at least in part based on sensing further includes selecting the starting frequency according to the interference threshold and at least in part based on the interference value of the starting frequency.

[0190] In an eighteenth aspect, either alone or in combination with one or more of the first to seventeenth aspects, selecting the starting frequency includes selecting the starting frequency at least in part based on a group indicated by the PRACH configuration.

[0191] In a nineteenth aspect, either alone or in combination with one or more of the first to eighteenth aspects, a resource set includes a first time resource and a second time resource consecutive to the first time resource.

[0192] In a twentieth aspect, either alone or in combination with one or more of the first to nineteenth aspects, a resource set includes a first time resource and a second time resource separated from the first time resource in time.

[0193] In a twenty - first aspect, either alone or in combination with one or more of the first to twentieth aspects, the PRACH configuration indicates the length of a frequency hopping pattern.

[0194] In a twenty-second aspect, alone or in combination with one or more of the first aspect to the twenty-first aspect, the length of the frequency hopping pattern is associated with a group indicated by the PRACH configuration.

[0195] In a twenty-third aspect, alone or in combination with one or more of the first aspect to the twenty-second aspect, transmitting the RACH preamble further includes transmitting the RACH preamble without having performed time synchronization after exiting the sleep mode.

[0196] In a twenty-fourth aspect, alone or in combination with one or more of the first aspect to the twenty-third aspect, transmitting the RACH preamble further includes transmitting the RACH preamble without having performed time synchronization or frequency synchronization after exiting the sleep mode.

[0197] In one aspect, method 1100 or any aspect related thereto may be performed by a device (such as Figure 13 communication device 1300), which includes various components operable to, configured to, or adapted to perform method 1100. Communication device 1300 is described in more detail below.

[0198] Note that Figure 11 is merely an example of a method, and according to the present disclosure, other methods including fewer, additional, or alternative steps are possible.

[0199] Figure 12 A method 1200 for wireless communication by a network entity such as BS110 or a decomposed base station as discussed with respect to Figure 3 is shown.

[0200] Method 1200 starts at 1210, outputting a PRACH configuration indicating a resource set for the RACH preamble.

[0201] Then, method 1200 proceeds to step 1220, receiving the RACH preamble on the resource set at the starting frequency and according to the frequency hopping pattern, where the transmission includes backscatter modulation of the input RF signal.

[0202] In a first aspect, the resource set includes a frequency resource set for the RACH preamble.

[0203] In a second aspect, alone or in combination with the first aspect, the resource set includes a time-frequency resource set for the RACH preamble.

[0204] In a third aspect, alone or in combination with one or more of the first aspect and the second aspect, the PRACH configuration indicates a time gap between the reception of the synchronization signal and the time-frequency resource set.

[0205] In a fourth aspect, alone or in combination with one or more of the first to third aspects, the resource set includes predefined resources.

[0206] In a fifth aspect, alone or in combination with one or more of the first to fourth aspects, method 1200 includes outputting a wake-up signal before receiving a RACH preamble, where receiving the RACH preamble includes receiving the RACH preamble at least partially based on the wake-up signal.

[0207] In a sixth aspect, alone or in combination with one or more of the first to fifth aspects, the PRACH configuration indicates one or more parameters for the wake-up signal.

[0208] In a seventh aspect, alone or in combination with one or more of the first to sixth aspects, the one or more parameters include at least one of the following: the periodicity of the wake-up signal, the frequency position of the wake-up signal, or the duration of the time window for transmitting the RACH preamble.

[0209] In an eighth aspect, alone or in combination with one or more of the first to seventh aspects, receiving the RACH preamble at least partially based on the wake-up signal further includes receiving the RACH preamble in a time window associated with the wake-up signal.

[0210] In a ninth aspect, alone or in combination with one or more of the first to eighth aspects, method 1200 includes outputting a sleep entry signal.

[0211] In a tenth aspect, alone or in combination with one or more of the first to ninth aspects, the PRACH configuration indicates one or more parameters for the sleep entry signal.

[0212] In an eleventh aspect, alone or in combination with one or more of the first to tenth aspects, the one or more parameters include at least one of the following: the periodicity of the sleep entry signal, the frequency position of the sleep entry signal, or the duration of the time window for transmitting the RACH preamble.

[0213] In a twelfth aspect, alone or in combination with one or more of the first to eleventh aspects, the starting frequency is at least partially based on a random function or a hash.

[0214] In a thirteenth aspect, alone or in combination with one or more of the first to twelfth aspects, the starting frequency is at least partially based on the UE sensing multiple frequencies.

[0215] In a fourteenth aspect, alone or in combination with one or more of the first to thirteenth aspects, the starting frequency is at least partially based on an interference threshold.

[0216] In a fifteenth aspect, alone or in combination with one or more of the first to fourteenth aspects, the starting frequency is at least partially based on the lowest interference value among the interference values of a plurality of frequencies having the starting frequency.

[0217] In a sixteenth aspect, alone or in combination with one or more of the first to fifteenth aspects, the starting frequency is at least partially based on an interference threshold and an interference value of the starting frequency.

[0218] In a seventeenth aspect, alone or in combination with one or more of the first to sixteenth aspects, the starting frequency is at least partially based on a group indicated by a PRACH configuration.

[0219] In an eighteenth aspect, alone or in combination with one or more of the first to seventeenth aspects, the resource set includes a first time resource and a second time resource consecutive to the first time resource.

[0220] In a nineteenth aspect, alone or in combination with one or more of the first to eighteenth aspects, the resource set includes a first time resource and a second time resource separated in time from the first time resource.

[0221] In a twentieth aspect, alone or in combination with one or more of the first to nineteenth aspects, the PRACH configuration indicates the length of a frequency hopping pattern.

[0222] In a twenty - first aspect, alone or in combination with one or more of the first to twentieth aspects, the length of the frequency hopping pattern is associated with a group indicated by the PRACH configuration.

[0223] In a twenty - second aspect, alone or in combination with one or more of the first to twenty - first aspects, receiving a RACH preamble further includes receiving a RACH preamble after the UE's sleep mode without having performed time synchronization with the UE.

[0224] In a twenty - third aspect, alone or in combination with one or more of the first to twenty - second aspects, receiving a RACH preamble further includes receiving a RACH preamble after the UE's sleep mode without having performed time synchronization or frequency synchronization with the UE.

[0225] In one aspect, method 1200 or any aspect related thereto may be performed by a device (such as Figure 14 communication device 1400) that includes various components operable to, configured to, or adapted to perform method 1200. Communication device 1400 is described in more detail below.

[0226] Note that Figure 12This is merely an example of a method, and according to the present disclosure, other methods including fewer, additional, or alternative steps are possible.

[0227] Figure 13 FIG. is an illustration of an example of a specific implementation of code and circuitry for a communication device 1300 according to the present disclosure. The communication device 1300 can be a UE, or the UE can include the communication device 1300.

[0228] The communication device 1300 includes a processing system 1302 coupled to a transceiver 1308 (e.g., a transmitter and / or a receiver). The transceiver 1308 is configured to transmit and receive signals for the communication device 1300 via an antenna 1310, such as the various signals described herein. The processing system 1302 can be configured to perform the processing functions of the communication device 1300, including processing signals received by and / or to be transmitted by the communication device 1300.

[0229] The processing system 1302 includes one or more processors 1320. In various aspects, the one or more processors 1320 can represent one or more of a receiving processor 258, a transmitting processor 264, a TX MIMO processor 266, and / or a controller / processor 280, as described with respect to Figure 2 The one or more processors 1320 are coupled to a computer-readable medium / memory 1330 via a bus 1306. In various aspects, the computer-readable medium / memory 1330 can represent a memory 282, as described with respect to Figure 2 In certain aspects, the computer-readable medium / memory 1330 is configured to store instructions (e.g., computer-executable code, processor-executable code) that, when executed by the one or more processors 1320, cause the one or more processors 1320 to perform the method 1100 described with respect to Figure 11 or any aspect associated therewith. Note that the reference to a processor that performs the functions of the communication device 1300 can include one or more processors that perform the functions of the communication device 1300.

[0230] As Figure 13 shown, the communication device 1300 can include circuitry (circuitry 1335) for receiving a PRACH configuration indicating a resource set for RACH preambles.

[0231] As Figure 13 shown, the communication device 1300 can include code (code 1340) stored in the computer-readable medium / memory 1330 for receiving a PRACH configuration indicating a resource set for RACH preambles.

[0232] As Figure 13As shown, the communication device 1300 may include circuitry (circuitry 1345) for receiving an input RF signal.

[0233] As Figure 13 shown, the communication device 1300 may include code (code 1350) stored in a computer-readable medium / memory 1330 for receiving an input RF signal.

[0234] As Figure 13 shown, the communication device 1300 may include circuitry (circuitry 1355) for selecting a starting frequency for a frequency hopping pattern for a RACH preamble.

[0235] As Figure 13 shown, the communication device 1300 may include code (code 1360) stored in a computer-readable medium / memory 1330 for selecting a starting frequency for a frequency hopping pattern for a RACH preamble.

[0236] As Figure 13 shown, the communication device 1300 may include circuitry for transmitting a RACH preamble in a resource set at the starting frequency and according to the frequency hopping pattern, where transmitting the RACH preamble includes backscatter modulation of the input RF signal (circuitry 1365).

[0237] As Figure 13 shown, the communication device 1300 may include code (code 1370) stored in a computer-readable medium / memory 1330 for transmitting a RACH preamble in a resource set at the starting frequency and according to the frequency hopping pattern, where transmitting the RACH preamble includes backscatter modulation of the input RF signal.

[0238] Various components of the communication device 1300 may provide components for performing the method 1100 described with respect to Figure 11 or any aspect related thereto. For example, components for transmitting, conveying, or outputting for transmission may include the transceiver 254 and / or antenna 252 of the UE 120, and / or Figure 13 the transceiver 1308 and antenna 1310 of the communication device 1300 in Figure 13 . Components for receiving or obtaining may include the transceiver 254 and / or antenna 252 of the UE 120, and / or

[0239] Figure 13 are provided as examples. Other examples may be different from the examples described in connection with Figure 13 .

[0240] Figure 14FIG. illustrates an example of a specific implementation of code and circuitry for a communication device 1400 in accordance with the present disclosure. The communication device 1400 may be a network entity (such as the BS110 or the split base station described with respect to Figure 3 ), or the network entity may include the communication device 1400.

[0241] The communication device 1400 includes a processing system 1402 coupled to a transceiver 1408 (e.g., a transmitter and / or a receiver). The transceiver 1408 is configured to transmit and receive signals for the communication device 1400 via an antenna 1410, such as the various signals described herein. The network interface 1412 is configured to obtain and transmit signals for the communication device 1400 via a communication link (such as the backhaul link, midhaul link, and / or fronthaul link described herein with respect to Figure 3 ). The processing system 1402 may be configured to perform the processing functions of the communication device 1400, including processing signals received by the communication device 1400 and / or to be transmitted by the communication device.

[0242] The processing system 1402 includes one or more processors 1420. In various aspects, the one or more processors 1420 may represent one or more of the receive processor 238, transmit processor 220, TX MIMO processor 230, and / or controller / processor 240, as described with respect to Figure 2 . The one or more processors 1420 are coupled to a computer-readable medium / memory 1430 via a bus 1406. In various aspects, the computer-readable medium / memory 1430 may represent the memory 242, as described with respect to Figure 2 . In certain aspects, the computer-readable medium / memory 1430 is configured to store instructions (e.g., computer-executable code, processor-executable code) that, when executed by the one or more processors 1420, cause the one or more processors 1420 to perform the method 1200 described with respect to Figure 12 or any aspect related thereto. Note that the reference to a processor that performs the functions of the communication device 1400 may include one or more processors that perform the functions of the communication device 1400.

[0243] As Figure 14 shown, the communication device 1400 may include circuitry (circuitry 1435) for outputting a PRACH configuration indicating a set of resources for a RACH preamble.

[0244] As Figure 14 shown, the communication device 1400 may include code (code 1440) stored in the computer-readable medium / memory 1430 for outputting a PRACH configuration indicating a set of resources for a RACH preamble.

[0245] As shown Figure 14 in FIG. 14, communication device 1400 may include circuitry for receiving a RACH preamble at a starting frequency and over a resource set according to a frequency hopping pattern, where transmission includes backscatter modulation of an input RF signal (circuitry 1445).

[0246] As shown Figure 14 in FIG. 14, communication device 1400 may include code stored in a computer-readable medium / memory 1430 for receiving a RACH preamble at a starting frequency and over a resource set according to a frequency hopping pattern, where transmission includes backscatter modulation of an input RF signal (code 1450).

[0247] Various components of communication device 1400 may provide components for performing the method 1100 described herein or any aspect associated therewith. For example, components for transmitting, conveying, or outputting for transmission may include transceiver 232 and / or antenna 234 of BS 110, and / or Figure 12 transceiver 1408 and antenna 1410 of communication device 1400 in FIG. 14. Components for receiving or obtaining may include transceiver 232 and / or antenna 234 of BS 110, and / or Figure 14 transceiver 1408 and antenna 1410 of communication device 1400 in FIG. 14. Figure 14 These are provided as examples. Other examples may be different from the examples described in conjunction with

[0248] Figure 14 FIG. 14. Figure 14 These examples are provided for illustrative purposes only. Other examples may be different from the examples described in conjunction with

[0249] An overview of some aspects of the present disclosure is provided below:

[0250] Aspect 1: A method of wireless communication performed by a user equipment (UE), the method comprising: receiving a physical random access channel (PRACH) configuration indicating a resource set for a random access channel (RACH) preamble; receiving an input radio frequency (RF) signal; selecting a starting frequency for a frequency hopping pattern for the RACH preamble; and transmitting the RACH preamble in the resource set at the starting frequency and according to the frequency hopping pattern, where transmitting the RACH preamble includes backscatter modulation of the input RF signal.

[0251] Aspect 2: The method according to aspect 1, wherein the resource set includes a frequency resource set for the RACH preamble.

[0252] Aspect 3: The method according to any one of aspects 1 to 2, wherein the resource set includes a time-frequency resource set for the RACH preamble.

[0253] Aspect 4: The method according to aspect 3, wherein the PRACH configuration indicates a time gap between reception of the synchronization signal and the set of time-frequency resources.

[0254] Aspect 5: The method according to any one of aspects 1 to 4, wherein the set of resources includes predefined resources.

[0255] Aspect 6: The method according to any one of aspects 1 to 5, the method further comprising receiving a wake-up signal before transmitting the RACH preamble, wherein transmitting the RACH preamble includes transmitting the RACH preamble at least partially based on the wake-up signal.

[0256] Aspect 7: The method according to aspect 6, wherein the PRACH configuration indicates one or more parameters for the wake-up signal.

[0257] Aspect 8: The method according to aspect 7, wherein the one or more parameters include at least one of the following: the periodicity of the wake-up signal, the frequency position of the wake-up signal, or the duration of the time window for transmitting the RACH preamble.

[0258] Aspect 9: The method according to aspect 6, wherein transmitting the RACH preamble at least partially based on the wake-up signal further includes transmitting the RACH preamble in a time window associated with the wake-up signal.

[0259] Aspect 10: The method according to any one of aspects 1 to 9, the method further comprising: receiving a go-to-sleep signal; and suppressing transmission of the RACH preamble during a time period associated with the go-to-sleep signal.

[0260] Aspect 11: The method according to aspect 10, wherein the PRACH configuration indicates one or more parameters for the go-to-sleep signal.

[0261] Aspect 12: The method according to aspect 11, wherein the one or more parameters include at least one of the following: the periodicity of the go-to-sleep signal, the frequency position of the go-to-sleep signal, or the duration of the time window for transmitting the RACH preamble.

[0262] Aspect 13: The method according to any one of aspects 1 to 12, wherein receiving the PRACH configuration further includes receiving the PRACH configuration before entering the sleep mode, and wherein transmitting the RACH preamble further includes transmitting the RACH preamble after exiting the sleep mode.

[0263] Aspect 14: The method according to any one of Aspects 1 to 13, wherein selecting the starting frequency includes selecting the starting frequency at least partially based on a random function or a hash.

[0264] Aspect 15: The method according to any one of Aspects 1 to 14, the method further comprising performing sensing of a plurality of frequencies, wherein selecting the starting frequency further includes selecting the starting frequency at least partially based on the sensing.

[0265] Aspect 16: The method according to Aspect 15, wherein selecting the starting frequency at least partially based on the sensing further includes selecting the starting frequency according to an interference threshold.

[0266] Aspect 17: The method according to Aspect 15, wherein selecting the starting frequency at least partially based on the sensing further includes selecting the starting frequency at least partially based on the starting frequency having the lowest interference value among the interference values of the plurality of frequencies.

[0267] Aspect 18: The method according to Aspect 15, wherein selecting the starting frequency at least partially based on the sensing further includes selecting the starting frequency according to an interference threshold and at least partially based on the interference value of the starting frequency.

[0268] Aspect 19: The method according to any one of Aspects 1 to 18, wherein selecting the starting frequency includes selecting the starting frequency at least partially based on a group indicated by the PRACH configuration.

[0269] Aspect 20: The method according to any one of Aspects 1 to 19, wherein the resource set includes a first time resource and a second time resource consecutive to the first time resource.

[0270] Aspect 21: The method according to any one of Aspects 1 to 20, wherein the resource set includes a first time resource and a second time resource separated from the first time resource in time.

[0271] Aspect 22: The method according to any one of Aspects 1 to 21, wherein the PRACH configuration indicates the length of the frequency hopping pattern.

[0272] Aspect 23: The method according to Aspect 22, wherein the length of the frequency hopping pattern is associated with a group indicated by the PRACH configuration.

[0273] Aspect 24: The method according to any one of Aspects 1 to 23, wherein transmitting the RACH preamble further includes transmitting the RACH preamble after exiting the sleep mode without having performed time synchronization.

[0274] Aspect 25: The method according to any one of Aspects 1 to 24, wherein transmitting the RACH preamble further comprises transmitting the RACH preamble after exiting the sleep mode without having performed time synchronization or frequency synchronization.

[0275] Aspect 26: A method of wireless communication performed by a network entity, the method comprising: outputting a physical random access channel (PRACH) configuration indicating a set of resources for a random access channel (RACH) preamble; and receiving the RACH preamble on the set of resources at a starting frequency and according to a frequency hopping pattern, wherein transmitting comprises backscatter modulation of an input RF signal.

[0276] Aspect 27: The method according to Aspect 26, wherein the set of resources comprises a set of frequency resources for the RACH preamble.

[0277] Aspect 28: The method according to any one of Aspects 26 to 27, wherein the set of resources comprises a set of time-frequency resources for the RACH preamble.

[0278] Aspect 29: The method according to Aspect 28, wherein the PRACH configuration indicates a time gap between reception of a synchronization signal and the set of time-frequency resources.

[0279] Aspect 30: The method according to any one of Aspects 26 to 29, wherein the set of resources comprises predefined resources.

[0280] Aspect 31: The method according to any one of Aspects 26 to 30, the method further comprising outputting a wake-up signal before receiving the RACH preamble, wherein receiving the RACH preamble comprises receiving the RACH preamble at least partially based on the wake-up signal.

[0281] Aspect 32: The method according to Aspect 31, wherein the PRACH configuration indicates one or more parameters for the wake-up signal.

[0282] Aspect 33: The method according to Aspect 32, wherein the one or more parameters comprise at least one of the following: the periodicity of the wake-up signal, the frequency position of the wake-up signal, or the duration of a time window for transmission of the RACH preamble.

[0283] Aspect 34: The method according to Aspect 31, wherein receiving the RACH preamble at least partially based on the wake-up signal further comprises receiving the RACH preamble in a time window associated with the wake-up signal.

[0284] Aspect 35: The method according to any one of aspects 26 to 34, the method further comprising: outputting a sleep entry signal.

[0285] Aspect 36: The method according to aspect 35, wherein the PRACH configuration indicates one or more parameters for the sleep entry signal.

[0286] Aspect 37: The method according to aspect 36, wherein the one or more parameters include at least one of the following: the periodicity of the sleep entry signal, the frequency position of the sleep entry signal, or the duration of the time window for transmitting the RACH preamble.

[0287] Aspect 38: The method according to any one of aspects 26 to 37, wherein the starting frequency is at least partially based on a random function or a hash.

[0288] Aspect 39: The method according to any one of aspects 26 to 38, wherein the starting frequency is at least partially based on a user equipment (UE) sensing multiple frequencies.

[0289] Aspect 40: The method according to any one of aspects 26 to 39, wherein the starting frequency is at least partially based on an interference threshold.

[0290] Aspect 41: The method according to any one of aspects 26 to 40, wherein the starting frequency is at least partially based on the lowest interference value among the interference values of multiple frequencies of the starting frequency.

[0291] Aspect 42: The method according to any one of aspects 26 to 41, wherein the starting frequency is at least partially based on the interference threshold and the interference value of the starting frequency.

[0292] Aspect 43: The method according to any one of aspects 26 to 42, wherein the starting frequency is at least partially based on a group indicated by the PRACH configuration.

[0293] Aspect 44: The method according to any one of aspects 26 to 43, wherein the resource set includes a first time resource and a second time resource consecutive to the first time resource.

[0294] Aspect 45: The method according to any one of aspects 26 to 44, wherein the resource set includes a first time resource and a second time resource separated in time from the first time resource.

[0295] Aspect 46: The method according to any one of aspects 26 to 45, wherein the PRACH configuration indicates the length of the frequency hopping pattern.

[0296] Aspect 47: The method according to aspect 46, wherein the length of the frequency hopping pattern is associated with a group indicated by the PRACH configuration.

[0297] Aspect 48: The method according to any one of aspects 26 to 47, wherein receiving the RACH preamble further comprises receiving the RACH preamble after a sleep mode of the user equipment (UE) without having performed time synchronization with the UE.

[0298] Aspect 49: The method according to any one of aspects 26 to 48, wherein receiving the RACH preamble further comprises receiving the RACH preamble after a sleep mode of the user equipment (UE) without having performed time synchronization or frequency synchronization with the UE.

[0299] Aspect 50: An apparatus for wireless communication at a 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 the method according to one or more of aspects 1 to 49.

[0300] Aspect 51: A device for wireless communication, the device comprising a memory and one or more processors coupled to the memory, the one or more processors configured to perform the method according to one or more of aspects 1 to 49.

[0301] Aspect 52: An apparatus for wireless communication, the apparatus comprising at least one component for performing the method according to one or more of aspects 1 to 49.

[0302] Aspect 53: A non-transitory computer-readable medium storing code for wireless communication, the code comprising instructions executable by a processor to perform the method according to one or more of aspects 1 to 49.

[0303] Aspect 54: A non-transitory computer-readable medium storing a set of instructions for wireless communication, the set of instructions comprising one or more instructions that, when executed by one or more processors of a device, cause the device to perform the method according to one or more of aspects 1 to 49.

[0304] While the foregoing disclosure provides illustration and description, it is not intended to be exhaustive or to limit the aspects to the precise forms disclosed. Modifications and variations may be made in light of the above disclosure, or may be obtained from practice of these aspects.

[0305] As used herein, the term "component" is intended to be broadly construed as hardware and / or a combination of hardware and software. "Software" should be broadly construed to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, processes, and / or functions, etc., regardless of whether it is referred to as software, firmware, middleware, microcode, hardware description language, or other names. As used herein, a "processor" is implemented in hardware and / or a combination of hardware and software. It will be apparent that the systems and / or methods described herein can be implemented by different forms of hardware and / or combinations of hardware and software. The actual specific control hardware or software code used to implement these systems and / or methods does not limit the various aspects. Thus, the operation and behavior of the systems and / or methods are not described herein with reference to specific software code, as those skilled in the art will understand that the software and hardware can be designed at least in part based on the description herein to implement the systems and / or methods.

[0306] As used herein, depending on the context, "meeting a threshold" can mean a value greater than the threshold, greater than or equal to the threshold, less than the threshold, less than or equal to the threshold, equal to the threshold, not equal to the threshold, etc.

[0307] Although specific combinations of features are recited in the claims and / or disclosed in the specification, these combinations are not intended to limit the disclosure of the various aspects. Many of these features can be combined in ways not specifically recited in the claims and / or not disclosed in the specification. The disclosure of the various aspects includes each dependent claim in combination with every other claim in the set of claims. As used herein, the phrase referring to "at least one of" a list of items means any combination of those items (which includes a single member). By way of 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 multiple 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).

[0308] None of the elements, acts, or instructions used herein should be construed as critical or essential unless explicitly described as such. Additionally, as used herein, the articles "a" and "an" are intended to include one or more items and may be used interchangeably with "one or more." Further, as used herein, the article "the" is intended to include one or more items mentioned in connection with the article "the" and may be used interchangeably with "one or more." Additionally, as used herein, the terms "group" and "set" are intended to include one or more items and may be used interchangeably with "one or more." If only one item is intended, the phrase "only one" or similar language is used. Additionally, as used herein, the terms "has," "have," "having," etc. are intended to be open-ended terms that do not limit the elements they modify (e.g., an element that "has" A may also have B). Further, the phrase "based on" is intended to mean "at least partially based on" unless otherwise explicitly stated. Additionally, as used herein, the term "or" when used in a series is intended to be open-ended and may be used interchangeably with "and / or" unless otherwise explicitly stated (e.g., if used in conjunction with "either" or "only one").

[0309] The foregoing description is provided to enable any person skilled in the art to practice the various aspects described herein. The examples discussed herein do not limit the scope, applicability, or aspects set forth in the claims. Various modifications to these aspects will be apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects. For example, the functions and arrangements of the elements discussed may be changed without departing from the scope of the disclosure. Various examples may omit, substitute, or add various processes or components as appropriate. For example, the methods described may be performed in a different order than described, and various actions may be added, omitted, or combined. Additionally, features described with respect to some examples may be combined in some other examples. For example, any number of the aspects set forth herein may be used to implement a device or practice a method. Additionally, the scope of the disclosure is intended to cover such devices or methods practiced using other structures, functions, or a combination of structures and functions that supplement or substitute for the various aspects of the disclosure set forth herein. It should be understood that any aspect of the disclosure herein may be embodied by one or more elements of the claims.

[0310] 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. While a general-purpose processor may be a microprocessor, in the alternative, the processor may be any commercially available processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, a system on a chip (SoC), or any other such configuration).

[0311] As used herein, the term "determine" covers a variety of actions. For example, "determine" may include computing, calculating, processing, deriving, investigating, looking up (e.g., looking up in a table, a database, or another data structure), ascertaining, etc. Further, "determine" may include receiving (e.g., receiving information), accessing (e.g., accessing data in a memory), etc. Still further, "determine" may include parsing, selecting, choosing, establishing, etc.

[0312] The methods disclosed herein include one or more actions for implementing 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 the 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 the methods described above may be performed by any suitable component capable of performing the corresponding functions. These components may include various hardware and / or software components and / or modules, including but not limited to circuits, application specific integrated circuits (ASICs), or processors.

[0313] The following claims are not intended to be limited to the aspects shown herein but should be accorded the full scope consistent with the claim language. In the claims, unless specifically stated otherwise, the recitation of a singular element is not intended to mean "one and only one" but rather "one or more." The term "some," unless specifically stated otherwise, 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 of the elements of the various aspects described throughout this disclosure that are known or later become known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be covered by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public, whether or not such disclosure is explicitly recited in the claims.

Claims

1. A method of wireless communication performed by a user equipment (UE), the method comprising: Receiving a physical random access channel (PRACH) configuration indicating a resource set for a random access channel (RACH) preamble; Receiving an input radio frequency (RF) signal; Selecting a starting frequency for a frequency hopping pattern for the RACH preamble; And Transmitting the RACH preamble in the resource set at the starting frequency and according to the frequency hopping pattern, wherein transmitting the RACH preamble includes backscatter modulation of the input RF signal.

2. The method according to claim 1, wherein the resource set includes a frequency resource set for the RACH preamble.

3. The method according to claim 1, wherein the resource set includes a time-frequency resource set for the RACH preamble.

4. The method according to claim 3, wherein the PRACH configuration indicates a time gap between reception of a synchronization signal and the time-frequency resource set.

5. The method according to claim 1, wherein the resource set includes predefined resources.

6. The method according to claim 1, the method further comprising receiving a wake-up signal before transmitting the RACH preamble, wherein transmitting the RACH preamble includes transmitting the RACH preamble at least partially based on the wake-up signal.

7. The method according to claim 6, wherein the PRACH configuration indicates one or more parameters for the wake-up signal.

8. The method according to claim 7, wherein the one or more parameters include at least one of the following: The periodicity of the wake-up signal, The frequency position of the wake-up signal, or The duration of a time window for transmission of the RACH preamble.

9. The method according to claim 6, wherein transmitting the RACH preamble at least partially based on the wake-up signal further includes transmitting the RACH preamble in a time window associated with the wake-up signal.

10. The method according to claim 1, the method further comprising: Receiving a go-to-sleep signal; And Suppressing transmission of the RACH preamble during a time period associated with the go-to-sleep signal.

11. The method according to claim 10, wherein the PRACH configuration indicates one or more parameters for the go-to-sleep signal.

12. The method according to claim 11, wherein the one or more parameters include at least one of the following: The periodicity of the go-to-sleep signal, The frequency position of the go-to-sleep signal, or The duration of a time window for transmission of the RACH preamble.

13. The method according to claim 1, wherein receiving the PRACH configuration further includes receiving the PRACH configuration before entering a sleep mode, and wherein transmitting the RACH preamble further includes transmitting the RACH preamble after exiting the sleep mode.

14. The method according to claim 1, wherein selecting the starting frequency includes selecting the starting frequency at least partially based on a random function or a hash.

15. The method according to claim 1, the method further comprising performing sensing of a plurality of frequencies, wherein selecting the starting frequency further comprises selecting the starting frequency at least in part based on the sensing.

16. The method according to claim 15, wherein selecting the starting frequency at least in part based on the sensing further comprises selecting the starting frequency according to an interference threshold.

17. The method according to claim 15, wherein selecting the starting frequency at least in part based on the sensing further comprises selecting the starting frequency at least in part based on the starting frequency having the lowest interference value among the interference values of the plurality of frequencies.

18. The method according to claim 15, wherein selecting the starting frequency at least in part based on the sensing further comprises selecting the starting frequency according to an interference threshold and at least in part based on the interference value of the starting frequency.

19. The method according to claim 1, wherein selecting the starting frequency comprises selecting the starting frequency at least in part based on a group indicated by the PRACH configuration.

20. The method according to claim 1, wherein the resource set comprises a first time resource and a second time resource consecutive to the first time resource.

21. The method according to claim 1, wherein the resource set comprises a first time resource and a second time resource separated in time from the first time resource.

22. The method according to claim 1, wherein the PRACH configuration indicates the length of the frequency hopping pattern.

23. A method of wireless communication performed by a network entity, the method comprising: outputting a physical random access channel (PRACH) configuration indicating a resource set for a random access channel (RACH) preamble; and receiving the RACH preamble on the resource set at a starting frequency and according to a frequency hopping pattern, wherein transmitting comprises backscatter modulation of an input radio frequency (RF) signal.

24. The method according to claim 23, wherein the resource set comprises a frequency resource set for the RACH preamble. The method according to claim 23, wherein the resource set comprises a time-frequency resource set for the RACH preamble.

26. The method according to claim 25, wherein the PRACH configuration indicates a time gap between reception of a synchronization signal and the time-frequency resource set.

27. The method according to claim 23, wherein the resource set comprises predefined resources.

28. The method according to claim 23, the method further comprising outputting a wake-up signal before receiving the RACH preamble, wherein receiving the RACH preamble comprises receiving the RACH preamble at least in part based on the wake-up signal.

29. A user equipment (UE) for wireless communication, the user equipment (UE) comprising: a memory; and one or more processors coupled to the memory and configured to: Receive a physical random access channel (PRACH) configuration indicating a resource set for a random access channel (RACH) preamble; Receive an input radio frequency (RF) signal; Select a starting frequency for a frequency hopping pattern for the RACH preamble; And Transmit the RACH preamble in the resource set at the starting frequency and according to the frequency hopping pattern, wherein transmitting the RACH preamble includes backscatter modulation of the input RF signal.

30. A network entity for wireless communication, the network entity comprising: A memory; And One or more processors coupled to the memory and configured to: Output a physical random access channel (PRACH) configuration indicating a resource set for a random access channel (RACH) preamble; and Receive the RACH preamble on the resource set at a starting frequency and according to a frequency hopping pattern, wherein transmitting includes backscatter modulation of an input radio frequency (RF) signal.

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