Configurable two-sided preamble for passive network device synchronization

Abstract

Certain aspects of the present disclosure provide techniques for uplink and / or downlink communication synchronization. A method generally includes receiving a first preamble in one or more first symbols; transmitting a first backscatter signal to the network entity based on the first preamble; and transmitting a carrier-based second backscatter signal to the network entity in one or more second symbols, the second backscatter signal comprising a second preamble, the second backscatter signal being transmitted in response to receiving the first preamble, wherein the one or more second symbols are offset in time relative to the one or more first symbols based on a timing offset configured at the device and a timing error offset of the device, and the second preamble is configured for synchronization of uplink communications between the device and the network entity.

Description

introduction Technical Field

[0001] Various aspects of this disclosure relate to wireless communication, and more specifically to techniques for uplink and / or downlink communication synchronization. Related technical descriptions

[0002] Wireless communication systems are widely deployed to provide a variety of telecommunications services, such as telephone, video, data, messaging, broadcasting, or other similar services. These wireless communication systems may employ multiple access technologies that enable communication with several users by sharing available wireless communication system resources.

[0003] Despite significant technological advancements in wireless communication systems over the years, challenges remain. For example, complex and dynamic environments can still attenuate or block signals between wireless transmitters and receivers. Therefore, there is a continuous expectation for improving the technical performance of wireless communication systems, including, for example: improving communication speed and data carrying capacity; improving the efficiency of shared communication media; reducing the power used by transmitters and receivers during 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; and increasing the number and types of available wireless communication media. Therefore, there is a need for further improvements to wireless communication systems to overcome the aforementioned technical challenges and other obstacles. Summary of the Invention

[0004] One aspect provides a method for wireless communication by a device. The method includes: receiving a first preamble in one or more first symbols; transmitting a first backscatter signal to a network entity based on the first preamble; and transmitting a carrier-based second backscatter signal to the network entity in one or more second symbols, the second backscatter signal including a second preamble, the second backscatter signal being transmitted in response to receiving the first preamble, wherein: the one or more second symbols are time-offset relative to the one or more first symbols based on a timing offset configured at the device and a timing error offset of the device, and the second preamble is configured for synchronization of uplink communication between the device and the network entity.

[0005] On the other hand, a method for wireless communication by a device is provided. The method includes: receiving a wake-up signal (WUS) in one or more first symbols while in a sleep state; transitioning from a sleep state to a wake-up state in response to receiving the WUS; and transmitting a carrier-based backscattered signal to a network entity in one or more second symbols, the backscattered signal including a preamble transmitted in response to receiving the WUS, wherein: the one or more second symbols are time-offset relative to the one or more first symbols based on a timing offset configured at the device and a timing error offset of the device, and the preamble is configured for synchronization of uplink communication between the device and the network entity.

[0006] On the other hand, a method for wireless communication by a device is provided. The method includes: transmitting a first preamble to at least one passive network device in one or more first symbols; receiving a first backscattered signal for the first preamble from at least one passive network device; calculating the round-trip time (RTT) of the first preamble; receiving a second backscattered signal from at least one passive network device in one or more second symbols, the second backscattered signal including the second preamble received in response to the transmission of the first preamble, wherein: the one or more second symbols are time-offset relative to one or more first symbols, and the second preamble is configured for synchronization of uplink communication between the device and at least one passive network device; determining a timing error offset of at least one passive network device based on the time offset between the one or more first symbols and the one or more second symbols, the RTT of the first preamble, and a timing offset configured at the device; and calculating a timing advance (TA) value for uplink communication between the device and at least one passive network device based on the RTT of the first preamble and the timing error offset of the at least one passive network device.

[0007] On the other hand, a method for wireless communication by a device is provided. The method includes: transmitting a WUS (Wireless Response System) to at least one passive network device in one or more first symbols while in a sleep state; receiving a backscattered signal from the at least one passive network device in one or more second symbols, the backscattered signal including a preamble received in response to the transmission of the WUS, wherein: the one or more second symbols are time-offset relative to the one or more first symbols, and the preamble is configured for synchronization of uplink communication between the device and the at least one passive network device; determining a timing error offset of the at least one passive network device based on the time offset between the one or more first symbols and the one or more second symbols and a timing offset configured at the at least one passive network device; and calculating a TA (Time Acquisition) value for uplink communication based on the timing error offset.

[0008] On the other hand, a method for wireless communication by a device is provided. The method includes: receiving a backscattered signal from at least one passive network device in one or more first symbols, the backscattered signal including a first preamble transmitted to the at least one passive network device by a radio frequency (RF) entity; determining the RTT of the first preamble; receiving a second backscattered signal including a second preamble from the at least one passive network device in one or more second symbols, wherein: the one or more second symbols are time-offset relative to one or more first symbols, and the second preamble is configured for synchronization of uplink communication between the device and the at least one passive network device; determining a timing error offset of the at least one passive network device based on the time offset between the one or more first symbols and the one or more second symbols, the RTT of the first preamble, and a timing offset configured at the device; and calculating a TA value for uplink communication between the device and the at least one passive network device based on the RTT of the first preamble and the timing error offset of the at least one passive network device.

[0009] On the other hand, a method for wireless communication by a device is provided. The method includes: determining that an RF entity transmits a WUS to at least one passive network device in one or more first symbols; receiving a backscattered signal from the at least one passive network device in one or more second symbols, the backscattered signal including a preamble received in response to the transmission of the WUS by the RF entity, wherein: the one or more second symbols are time-offset relative to one or more first symbols, and the preamble is configured for synchronization of uplink communication between the device and the at least one passive network device; determining a timing error offset of the at least one passive network device based on the time offset between the one or more first symbols and the one or more second symbols and a timing offset configured at the at least one passive network device; and calculating a TA value for uplink communication based on the timing error offset.

[0010] Other aspects provide: one or more means capable of operating to, configured to, or otherwise adapted to perform any portion of any method described herein (e.g., such that execution can be performed by only one means or in a distributed manner across multiple means); one or more non-transitory computer-readable media comprising instructions that, when executed by one or more processors of the one or more means, cause the one or more means to perform any portion of any method described herein (e.g., such that instructions can be included in only one computer-readable medium or in a distributed manner across multiple computer-readable media, such that instructions can be executed by only one processor or by multiple processors in a distributed manner, such that the one or more means can perform any portion of any method described herein). Each device in the apparatus may include one or more processors, and / or enable execution to be performed by only one device or in a distributed manner across multiple devices; one or more computer program products embodied on one or more computer-readable storage media including code for performing any part of any method described herein (e.g., enabling the code to be stored in only one computer-readable medium or in a distributed manner across computer-readable media); and / or one or more devices including one or more components for performing any part of any method described herein (e.g., enabling execution to be performed by only one device or by multiple devices in a distributed manner). By way of example, an apparatus may include a processing system, a device having a processing system, or a processing system cooperating via one or more networks.

[0011] For illustrative purposes, the following description and figures illustrate certain features. Attached Figure Description

[0012] The accompanying drawings depict certain features of the various aspects described herein and should not be considered as limiting the scope of this disclosure.

[0013] Figure 1 An example wireless communication network is depicted.

[0014] Figure 2 An example decomposed base station architecture is described.

[0015] Figure 3 Various aspects of the example base station and example user equipment (UE) are described.

[0016] Figure 4A , Figure 4B , Figure 4C and Figure 4D Various example aspects of data structures used in wireless communication networks are described.

[0017] Figure 5A An example passive network device is described.

[0018] Figures 5B to 5F An example deployment scenario for passive network devices is described.

[0019] Figure 6 The process flow is described for communication between network entities and passive network devices in a network to achieve synchronization when the preamble sent by the network entity is enabled.

[0020] Figure 7 The process flow is described for communication between radio frequency entities, network entities, and passive network devices in a network to achieve synchronization when the preamble transmitted by the radio frequency entity is enabled.

[0021] Figure 8 The process flow for achieving synchronization between network entities and passive network devices in a network is described when the preamble sent by the network entity is disabled.

[0022] Figure 9 The process flow is described for achieving synchronization in a network by communicating between radio frequency entities, network entities, and passive network devices when the preamble transmitted by the radio frequency entity is disabled.

[0023] Figure 10 The process flow for communicating between network entities and passive network devices in a network using group-specific wake-up signals is described.

[0024] Figure 11 Example correlation peaks for detecting preamble collisions are depicted.

[0025] Figure 12 A method for wireless communication is described.

[0026] Figure 13 Another method for wireless communication is described.

[0027] Figure 14 Another method for wireless communication is described.

[0028] Figure 15 Another method for wireless communication is described.

[0029] Figure 16 Another method for wireless communication is described.

[0030] Figure 17 Another method for wireless communication is described.

[0031] Figure 18 Various aspects of the example communication device are described.

[0032] Figure 19 Various aspects of the example communication device are described. Detailed Implementation

[0033] This disclosure provides apparatus, methods, processing systems, and computer-readable media for synchronization of passive network devices. Specifically, certain aspects introduce a two-sided preamble (e.g., a preamble is a signal used in network communications to synchronize transmission timing between two or more devices), which can be configured for synchronization of uplink and / or downlink communications between network entities and passive network devices, such as Ambient Internet of Things (A-IoT) devices (e.g., A-IoT User Equipment (UE)). Uplink communication synchronization (or simply "uplink synchronization") is a process for determining the exact timing for transmitting uplink data. Downlink communication synchronization (or simply "downlink synchronization") is a process for detecting radio boundaries (i.e., the exact timing of the start of a radio frame) and Orthogonal Frequency Division Multiplexing (OFDM) symbol boundaries (i.e., the exact timing of the start of an OFDM symbol).

[0034] While this paper discusses certain aspects of using configurable two-sided preambles for A-IoT device synchronization, it should be noted that configurable two-sided preambles can be used for synchronization of other suitable passive network devices. As used herein, a passive network device can refer to a wireless device that supports ambient-powered transmission, energy harvesting, passive transmission, and / or backscatter communication. Passive network devices may also be referred to as tags, passive user equipment (UE), passive devices, and / or other similar devices of any shape or form. In some cases, passive network devices act as network entities acting as relays.

[0035] A-IoT devices typically have a low-complexity design configured to transmit (e.g., send and / or receive) wireless signals using low power. For example, A-IoT devices may often have limited energy storage capabilities, such as limited batteries or capacitors, or other short-term energy storage devices. In some cases, A-IoT devices rely on energy harvesting from one or more external sources. These external sources may include, for example, solar energy, thermal energy, kinetic energy, RF energy, electromagnetic radiation (EMR), and other types of ambient energy. For example, an A-IoT device may include one or more components that allow it to harvest energy, such as solar cells and RF power converters. Example A-IoT devices include tags, such as radio frequency identification (RFID) tags, passive UEs, and backscatter UEs.

[0036] A-IoT devices may not include active RF components, but instead can communicate using passive radio equipment (e.g., backscatter radio components). For example, A-IoT devices may not have power amplifiers or low-noise amplifiers. A-IoT devices typically utilize lightweight protocol stacks.

[0037] Some existing communication systems for passive network devices (such as RFID) are asynchronous to reduce complexity, but at the cost of inefficiency. However, when these passive network devices (e.g., A-IoT devices) are deployed in radio access networks (RANs) (such as 3G, 4G, 5G, 6G, and / or other generations of RAN architectures), asynchronous communication capabilities exhibit compatibility issues and impact system efficiency. Specifically, accurate and reliable synchronization has long been a fundamental prerequisite for high efficiency / performance in RANs. Furthermore, the importance of synchronization has grown with the emergence of new radio technologies and network architectures used to improve efficiency and support demanding 5G and / or 6G use cases. For example, synchronization enables the alignment of communications between devices to help prevent interference and thus helps ensure seamless and efficient communication between devices within the RAN architecture. Therefore, it may be necessary to consider techniques for synchronizing communication with passive network devices to utilize them in the RAN while maintaining efficient communication between devices within these networks.

[0038] Therefore, certain aspects of this document provide solutions for synchronization of passive network devices, such as A-IoT device synchronization. Specifically, these solutions introduce configurable bilateral preambles that can be used for synchronization of uplink and / or downlink communications between a network entity and a passive network device. As used herein, a downlink may be associated with a “forward link” representing a link from a network entity to a passive network device, and an uplink may be associated with a “reverse link” representing a link from a passive network device to a network entity. Bilateral preambles may include: (1) a first preamble sent by a network entity or radio frequency (RF) entity (e.g., another network entity) to a passive network device for downlink synchronization and, in some cases, for assisting uplink synchronization; and (2) a second preamble sent by a passive network device to a network entity for uplink synchronization. The first preamble may be configurable such that, in some cases, the first preamble is disabled and only the second preamble is sent. In other cases, both the first and second preambles are sent.

[0039] In some aspects, passive network devices (e.g., A-IoT devices) are configured to transmit a second preamble in response to receiving a first preamble (e.g., if the first preamble is enabled). The passive network device may transmit the second preamble based on a timing offset configured at the passive network device, where the timing offset is the time period the passive network device expects to wait between receiving the first preamble and transmitting the second preamble. In some other aspects, passive network devices (e.g., A-IoT devices) are configured to transmit the second preamble in response to receiving a Wake-Up Signal (WUS) indicating that transmission is disabled for the first preamble. The passive network device may transmit the second preamble based on a timing offset configured at the passive network device, where the timing offset is the time period the passive network device expects to wait after receiving the WUS and before transmitting the second preamble. In either case, the passive network device transmits the second preamble by modulating the second preamble in the reflection (i.e., backscatter) of a carrier received at the passive network device. For example, using passive radio equipment, a passive network device is configured to backscatter and modulate an incident RF signal (e.g., a carrier). For example, another device (e.g., a network entity, an RF entity, etc.) may transmit the carrier in the direction of the passive network device. The passive network device uses passive radio equipment to backscatter the carrier (e.g., backscatter the carrier as a backscatter signal) and modulates a second preamble in the backscatter to transmit the second preamble to the network entity for uplink synchronization.

[0040] The network entity receiving the second preamble can expect the passive network device to transmit the second preamble after a configured timing offset (e.g., also known to the network entity); however, due to the low power and complexity of the passive network device, the clock at the passive network device may have low accuracy. Therefore, the transmission of the second preamble by the passive network device may actually occur later (or earlier) than expected. The time difference between the actual transmission time of the second preamble and the expected transmission time can represent the timing error offset of the passive network device. The network entity receiving the second preamble can determine this timing error offset based at least on the timing of receiving the second preamble and the configured timing offset, and use this timing error offset to synchronize uplink communication between the network entity and the passive network device.

[0041] Therefore, the configurable two-sided preamble described herein allows for synchronization between passive network devices (such as A-IoT devices) and other network devices. This synchronization helps improve the efficiency and reliability of communication within networks in which devices are deployed, resulting in numerous beneficial technical effects. Introduction to wireless communication networks

[0042] The techniques and methods described herein can be used in a variety of wireless communication networks. Although aspects herein may be described using terms commonly associated with 3G, 4G, 5G, 6G, and / or other generations of wireless technologies, aspects of this disclosure are equally applicable to other communication systems and standards not explicitly mentioned herein.

[0043] Figure 1 An example of a wireless communication network 100 in which the aspects described herein can be implemented is depicted.

[0044] Generally, 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 station (BS), components of a BS, servers, etc.). Since such communication devices are part of wireless communication network 100 and facilitate wireless communication, they may be referred to as wireless communication devices. For example, various functions of the network and various devices associated with and interacting with the network may be considered network entities. Furthermore, wireless communication network 100 includes terrestrial aspects (also referred to herein as non-terrestrial network entities) and non-terrestrial aspects. Terrestrial aspects include ground-based network entities (e.g., BS 102), and non-terrestrial aspects include satellite 140 and aircraft 145, which may include onboard network entities (e.g., one or more BSs) capable of communicating with other network elements (e.g., terrestrial BSs) and UEs.

[0045] In the depicted example, wireless communication network 100 includes BS 102, UE 104 and one or more core networks (such as Evolved Packet Core (EPC) 160 and 5G Core (5GC) network 190) that interoperate to provide communication services over various communication links, including wired and wireless links.

[0046] Figure 1Various example UEs 104 are described, which may more generally include: cellular phones, smartphones, Session Initiation Protocol (SIP) phones, laptops, personal digital assistants (PDAs), satellite radios, global positioning systems, multimedia devices, video devices, digital audio players, cameras, game consoles, tablets, smart devices, wearable devices, vehicles, electricity meters, air pumps, large or small kitchen appliances, healthcare devices, implants, sensors / actuators, displays, Internet of Things (IoT) devices, always-on (AON) devices, edge processing devices, data centers, or other similar devices. UE 104 may also be more generally referred to as mobile devices, wireless devices, stations, mobile stations, subscriber stations, mobile subscriber stations, mobile units, subscriber units, wireless units, remote units, remote devices, access terminals, mobile terminals, wireless terminals, remote terminals, mobile phones, and others.

[0047] BS 102 communicates wirelessly with UE 104 via communication link 120 (e.g., sending or receiving signals to or from UE 104). Communication link 120 between BS 102 and UE 104 may include uplink (UL) transmission (also referred to as reverse link) from UE 104 to BS 102 and / or downlink (DL) transmission (also referred to as forward link) transmission from BS 102 to UE 104. In various aspects, communication link 120 may utilize multiple-input multiple-output (MIMO) antenna technologies, including spatial multiplexing, beamforming, and / or transmit diversity.

[0048] BS 102 may typically include: NodeB, enhanced NodeB (eNB), next-generation enhanced NodeB (ng-eNB), next-generation NodeB (gNB or gNodeB), access point, transceiver base station, radio base station, radio transceiver, transceiver functionality, transmit / receive point, and / or others. Each of BS 102 provides communication coverage for a corresponding coverage area 110, which may sometimes be referred to as a cell, and in some cases may overlap (e.g., a small cell 102' may have a coverage area 110' that overlaps with the coverage area 110 of a macro cell). For example, BS may provide communication coverage for macro cells (covering a relatively large geographic area), pico cells (covering a relatively small geographic area, such as a stadium), femtocells (covering a relatively small geographic area (e.g., a home)), and / or other types of cells.

[0049] Generally, a cell can refer to a portion, partition, or segment of wireless communication coverage served by network entities within a wireless communication network. A cell can have geographical characteristics (such as a geographical coverage area) and radio frequency characteristics (such as time and / or frequency resources dedicated to the cell). For example, multiple cells employing different frequency resources (e.g., bandwidth portions) and / or different time resources can cover a specific geographical coverage area. As another example, a single cell can cover a specific geographical coverage area. In some contexts (e.g., carrier aggregation scenarios and / or multi-connectivity scenarios), the terms "cell" or "serving cell" can refer to or correspond to a specific carrier frequency (e.g., component carrier) used for wireless communication, and "cell group" can refer to or correspond to multiple carriers used for wireless communication. As an example, in a carrier aggregation scenario, a UE can communicate on multiple component carriers corresponding to multiple (serving) cells in the same cell group, and in a multi-connectivity (e.g., dual-connectivity) scenario, a UE can communicate on multiple component carriers corresponding to multiple cell groups.

[0050] Although BS 102 is described as a single communication device in various aspects, it can be implemented in a variety of configurations. For example, to give a few examples, one or more components of the base station can 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. In another example, various aspects of the base station can be virtualized. More generally, a base station (e.g., BS 102) can include components located at a single physical location or components located at various physical locations. In examples where the base station includes components located at various physical locations, the various components can each perform functions, such that the various components collectively achieve functionality similar to a base station located at a single physical location. In some aspects, a base station including components located at various physical locations can be referred to as a decomposed radio access network architecture (such as an open RAN (O-RAN) or virtualized RAN (VRAN) architecture). Figure 2 An example decomposed base station architecture is depicted and described.

[0051] Different BSs 102 within the wireless communication network 100 can also be configured to support different radio access technologies (such as 3G, 4G, and / or 5G). For example, a BS 102 configured for 4G LTE (collectively referred to as Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN)) can interface with EPC 160 via a first backhaul link 132 (e.g., S1 interface). A BS 102 configured for 5G (e.g., 5G NR or Next Generation RAN (NG-RAN)) can interface with 5GC 190 via a second backhaul link 184. BSs 102 can communicate directly or indirectly (e.g., via EPC 160 or 5GC 190) on a third backhaul link 134 (e.g., X2 interface), which can be wired or wireless.

[0052] Wireless communication network 100 can subdivide the electromagnetic spectrum into various categories, bands, channels, or other characteristics. In some aspects, subdivision is provided based on wavelength and frequency, where frequency may also be referred to as carrier, subcarrier, channel, tone, or subband. For example, 3GPP currently defines frequency range 1 (FR1) as including 410MHz to 7125MHz, which is often (interchangeably) referred to as “sub-6GHz”. Similarly, 3GPP currently defines frequency range 2 (FR2) as including 24,250MHz to 71,000MHz, which is sometimes (interchangeably) referred to as “millimeter wave” (“mmW” or “mmWave”). In some cases, FR2 can be further defined according to subranges (such as a first subrange FR2-1 including 24,250MHz to 52,600MHz and a second subrange FR2-2 including 52,600MHz to 71,000MHz). Base stations configured to communicate using mmWave / near mmWave radio bands (e.g., mmWave base stations such as BS 180) can utilize beamforming (e.g., 182) with UEs (e.g., 104) to improve path loss and range.

[0053] The communication link 120 between BS 102 and, for example, UE 104 can be via one or more carriers, which may have different bandwidths (e.g., 5MHz, 10MHz, 15MHz, 20MHz, 100MHz, 400MHz and / or other MHz) and may be aggregated in various ways. The carriers may be adjacent to each other or may not be adjacent to each other. The allocation of carriers may be asymmetric with respect to DL and UL (e.g., more or fewer carriers may be allocated to DL compared to UL).

[0054] Compared to lower-frequency communication, communication using higher frequency bands may have higher path loss and shorter range. Therefore, some base stations (e.g., Figure 1 The beamforming 182 of the BS 180 (180) with the UE 104 can be used to improve path loss and range. For example, the BS 180 and UE 104 may each include multiple antennas, such as antenna elements, antenna panels, and / or antenna arrays, to facilitate beamforming. In some cases, the BS 180 may transmit beamformed signals to the UE 104 in one or more transmit directions 182''. The UE 104 may receive beamformed signals from the BS 180 in one or more receive directions 182''. The UE 104 may also transmit beamformed signals to the BS 180 in one or more transmit directions 182''. The BS 180 may also receive beamformed signals from the UE 104 in one or more receive directions 182''. The BS 180 and UE 104 may then perform beamforming training to determine the optimal receive and transmit directions for each of the BS 180 and UE 104. It is worth noting that the transmit and receive directions of the BS 180 may be the same or different. Similarly, the sending and receiving directions of UE 104 may be the same or different.

[0055] The wireless communication network 100 also includes a Wi-Fi AP 150 that communicates with a Wi-Fi station (STA) 152 via a communication link 154 in, for example, unlicensed spectrum in 2.4 GHz and / or 5 GHz.

[0056] Some UEs 104 may use device-to-device (D2D) communication link 158 to communicate with each other. The D2D communication link 158 may use one or more sidelink channels, such as 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).

[0057] EPC 160 may include various functional components, including: Mobility Management Entity (MME) 162, other MMEs 164, Serving Gateway 166, Multimedia Broadcast Multicast Service (MBMS) Gateway 168, Broadcast Multicast Service Center (BM-SC) 170, and / or Packet Data Network (PDN) Gateway 172, as in the illustrated example. MME 162 may communicate with Home Subscriber Server (HSS) 174. MME 162 is the control node that handles signaling between UE 104 and EPC 160. Generally, MME 162 provides bearer and connectivity management.

[0058] Generally, user Internet Protocol (IP) packets are transmitted through Serving Gateway 166, which is itself connected to PDN Gateway 172. PDN Gateway 172 provides UE IP address allocation and other functions. PDN Gateway 172 and BM-SC 170 are connected to IP services 176, which may include, for example, the Internet, intranets, IP Multimedia Subsystem (IMS), packet-switched (PS) streaming services, and / or other IP services.

[0059] The BM-SC 170 provides functionality for MBMS user service dispatch and delivery. The BM-SC 170 can serve as an entry point for content provider MBMS transmissions, authorize and initiate MBMS bearer services within a Public Land Mobile Network (PLMN), and / or schedule MBMS transmissions. The MBMS Gateway 168 can distribute MBMS services to BS 102 within a Broadcast-Specific Service Single Frequency Network (MBSFN) area, and / or be responsible for session management (start / stop) and collecting eMBMS-related billing information.

[0060] 5GC 190 may include various functional components, including: Access and Mobility Management Function (AMF) 192, other AMFs 193, Session Management Function (SMF) 194, and User Plane Function (UPF) 195. AMF 192 may communicate with Unified Data Management (UDM) 196.

[0061] AMF 192 is the control node that handles signaling between UE 104 and 5GC 190. AMF 192 provides services such as Quality of Service (QoS) flow and session management.

[0062] Internet Protocol (IP) packets are transmitted via UPF 195, which connects to IP service 197 and provides UE IP address allocation and other functions for 5GC 190. IP service 197 may include, for example, the Internet, intranet, IMS, PS streaming service, and / or other IP services.

[0063] In various aspects, to give a few examples, network entities or network nodes can be implemented as aggregated base stations, decomposed base stations, components of base stations, integrated access and backhaul (IAB) nodes, relay nodes, and sidelink nodes.

[0064] Figure 2An example decomposed base station 200 architecture is depicted. The decomposed base station 200 architecture may include one or more central units (CUs) 210, which may communicate directly with the core network 220 via a backhaul link, or indirectly with the core network 220 through one or more decomposed base station units, such as a near real-time (near-RT) RAN Intelligent Controller (RIC) 225 via an E2 link, or a non-real-time (non-RT) RIC 215 associated with a Service Management and Orchestration (SMO) framework 205, or both. CUs 210 may communicate with one or more distributed units (DUs) 230 via corresponding midhaul links (such as F1 interfaces). DUs 230 may communicate with one or more radio units (RUs) 240 via corresponding fronthaul links. RUs 240 may communicate with a corresponding UE 104 via one or more radio frequency (RF) access links. In some specific implementations, UE 104 may be served simultaneously by multiple RUs 240.

[0065] Each unit in a cell (e.g., CU 210, DU 230, RU 240, and near-RT RIC 225, non-RT RIC 215, and SMO frame 205) may include or be coupled to one or more interfaces configured to receive or transmit signals, data, or information (collectively, signals) via a wired or wireless transmission medium. Each of the cells, or an associated processor or controller that provides instructions to the cell's communication interface, may be configured to communicate with one or more other cells via the transmission medium. For example, these cells may include a wired interface configured to receive signals or transmit signals to one or more other cells via a wired transmission medium. Additionally or alternatively, a cell may include a wireless interface that may include a receiver, transmitter, or transceiver (such as a radio frequency (RF) transceiver) configured to receive signals on a wireless transmission medium or transmit signals to one or more other cells, or both.

[0066] In some aspects, CU 210 can host one or more higher-level control functions. Such control functions may include Radio Resource Control (RRC), Packet Data Convergence Protocol (PDCP), Serving Data Adaptation Protocol (SDAP), etc. Each control function can be implemented using an interface configured to signal to other control functions hosted by CU 210. CU 210 can 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 combinations thereof. In some implementations, CU 210 can be logically divided into one or more CU-UP units and one or more CU-CP units. When implemented in an O-RAN configuration, CU-UP units can communicate bidirectionally with CU-CP units via an interface such as an E1 interface. CU 210 can be implemented to communicate with DU 230 for network control and signaling transmission as needed.

[0067] DU 230 may correspond to a logical unit that includes one or more base station functions for controlling the operation of one or more RU 240s. In some aspects, DU 230 may host one or more of the Radio Link Control (RLC) layer, Medium Access Control (MAC) layer, and one or more high physical (PHY) layers (such as modules for forward error correction (FEC) encoding and decoding, scrambling, modulation and demodulation, etc.) at least in part according to functional splits (such as those defined by the 3rd Generation Partnership Project (3GPP). In some aspects, DU 230 may also host one or more low PHY layers. Each layer (or module) may be implemented using an interface configured to communicate signals with other layers (and modules) hosted by DU 230 or with control functions hosted by CU 210.

[0068] Lower-layer functionality can be implemented by one or more RU 240s. In some deployments, the RU240 controlled by the DU 230 may correspond to a logical node that hosts RF processing functions or low-PHY layer functions (such as performing Fast Fourier Transform (FFT), Inverse FFT (iFFT), digital beamforming, or Physical Random Access Channel (PRACH) extraction and filtering, or both, at least in part based on functional decomposition (such as lower-layer functional decomposition). In such architectures, the RU 240 may be implemented to handle over-the-air (OTA) communications with one or more UE 104s. In some specific implementations, the real-time and non-real-time aspects of control plane and user plane communications with the RU 240 may be controlled by the corresponding DU 230. In some scenarios, this configuration allows the DU 230 and CU 210 to be implemented in a cloud-based RAN architecture (such as a vRAN architecture).

[0069] SMO framework 205 can be configured to support RAN deployment and provisioning of both non-virtualized and virtualized network elements. For non-virtualized network elements, SMO framework 205 can be configured to support the deployment of dedicated physical resources for RAN coverage requirements, which can be managed via operation and maintenance interfaces such as the O1 interface. For virtualized network elements, SMO framework 205 can be configured to interact with cloud computing platforms such as Open Cloud (O-Cloud) 290 to perform network element lifecycle management (such as instantiating virtualized network elements) via cloud computing platform interfaces such as the O2 interface. Such virtualized network elements may include, but are not limited to, CU 210, DU 230, RU 240, and near-RT RIC 225. In some specific implementations, SMO framework 205 may communicate with the hardware aspects of the 4G RAN (such as Open eNB (O-eNB) 211) via the O1 interface. Additionally, in some implementations, the SMO framework 205 may communicate directly with one or more DU 230s and / or one or more RU 240s via the O1 interface. The SMO framework 205 may also include a non-RT RIC 215 configured to support the functionality of the SMO framework 205.

[0070] The non-RT RIC 215 can be configured to include logical functions that enable non-real-time control and optimization of RAN elements and resources, including artificial intelligence / machine learning (AI / ML) workflows for model training and updates, or policy-based guidance for applications / features in the near-RT RIC 225. The non-RT RIC 215 can be coupled to or communicate with the near-RT RIC 225, such as via an A1 interface. The near-RT RIC 225 can be configured to include logical functions that enable near real-time control and optimization of RAN elements and resources via an interface, such as via an E2 interface, through data collection and actions, connecting one or more CU 210s, one or more DU 230s, or both, and O-eNBs to the near-RT RIC 225.

[0071] In some implementations, to generate AI / ML models to be deployed in the near-RT RIC 225, the non-RT RIC 215 may receive parameters or external enrichment information from an external server. This information can be utilized by the near-RT RIC 225 and may be received from non-network data sources or network functions at the SMO framework 205 or the non-RT RIC 215. In some examples, the non-RT RIC 215 or the near-RT RIC 225 may be configured to tune RAN behavior or performance. For example, the non-RT RIC 215 may monitor long-term trends and patterns in performance and employ AI / ML models to perform corrective actions via the SMO framework 205 (such as reconfiguration via O1) or by creating RAN management policies (such as A1 policies).

[0072] Figure 3 Various aspects of examples BS 102 and UE 104 are described.

[0073] Generally, BS 102 includes various processors (e.g., 318, 320, 330, 338, and 340), antennas 334a to 334t (collectively referred to as 334), transceivers 332a to 332t (collectively referred to as 332) including modulators and demodulators, and other aspects that enable the wireless transmission of data (e.g., data source 312) and the wireless reception of data (e.g., data sink 314). For example, BS 102 can transmit and receive data between BS 102 and UE 104. BS 102 includes a controller / processor 340 that can be configured to implement the various wireless communication-related functions described herein.

[0074] Generally, UE 104 includes various processors (e.g., 358, 364, 366, 370, and 380), antennas 352a to 352r (collectively referred to as 352), transceivers 354a to 354r (collectively referred to as 354) including modulators and demodulators, and other aspects that enable the wireless transmission of data (e.g., retrieval from data source 362) and the wireless reception of data (e.g., provision to data sink 360). UE 104 includes a controller / processor 380 that can be configured to implement the various wireless communication-related functions described herein.

[0075] Regarding example downlink transmission, BS 102 includes a transmission processor 320 that can receive data from data source 312 and control information from controller / processor 340. This control information may be for a Physical Broadcast Channel (PBCH), Physical Control Format Indicator Channel (PCFICH), Physical Hybrid Automatic Repeat Request (HARQ) Indicator Channel (PHICH), Physical Downlink Control Channel (PDCCH), Group Common PDCCH (GC PDCCH), and / or others. In some examples, this data may be for a Physical Downlink Shared Channel (PDSCH).

[0076] The transmitter processor 320 can process data and control information (e.g., encoding and symbol mapping) to obtain data symbols and control symbols, respectively. The transmitter processor 320 can also generate reference symbols (such as those for the primary synchronization signal (PSS), secondary synchronization signal (SSS), PBCH demodulation reference signal (DMRS), and channel state information reference signal (CSI-RS)).

[0077] The transmit (TX) multiple-input multiple-output (MIMO) processor 330 can perform spatial processing (e.g., pre-decoding) on ​​data symbols, control symbols, and / or reference symbols where applicable, and can provide the output symbol stream to the modulators (MODs) in transceivers 332a to 332t. Each modulator in transceivers 332a to 332t can process its corresponding output symbol stream to obtain an output sample stream. Each modulator can further process (e.g., convert to analog, amplify, filter, and up-convert) the output sample stream to obtain a downlink signal. The downlink signal from the modulators in transceivers 332a to 332t can be transmitted via antennas 334a to 334t, respectively.

[0078] To receive downlink transmissions, UE 104 includes antennas 352a to 352r that receive downlink signals from BS 102 and provide the received signals to demodulators (DEMODs) in transceivers 354a to 354r, respectively. Each demodulator in transceivers 354a to 354r can modulate (e.g., filter, amplify, down-convert, and digitize) the corresponding received signal to obtain an input sample. Each demodulator can further process the input sample to obtain the received symbols.

[0079] The RX MIMO detector 356 acquires received symbols from all demodulators in transceivers 354a to 354r, performs MIMO detection on the received symbols where applicable, and provides the detected symbols. The receive processor 358 processes the detected symbols (e.g., demodulation, deinterleaving, and decoding), provides the decoded data of UE 104 to data sink 360, and provides the decoded control information to controller / processor 380.

[0080] Regarding example uplink transmission, UE 104 also includes a transmit processor 364 that receives and processes data from data source 362 (e.g., for PUSCH) and control information from controller / processor 380 (e.g., for Physical Uplink Control Channel (PUCCH)). Transmit processor 364 may also generate reference symbols for reference signals (e.g., for Sounding Reference Signal (SRS)). Symbols from transmit processor 364 may be pre-decoded by TX MIMO processor 366 where applicable, further processed by modulators in transceivers 354a to 354r (e.g., for SC-FDM), and transmitted to BS 102.

[0081] At BS 102, uplink signals from UE 104 can be received by antennas 334a to 334t, processed by demodulators in transceivers 332a to 332t, detected where applicable by RX MIMO detector 336, and further processed by receiver processor 338 to obtain decoded data and control information transmitted by UE 104. Receiver processor 338 can provide the decoded data to data sink 314 and the decoded control information to controller / processor 340.

[0082] Memory 342 and memory 382 can store data and program code for BS 102 and UE 104, respectively.

[0083] Scheduler 344 can schedule UE to send data on the downlink and / or uplink.

[0084] In various respects, BS 102 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 that output data, such as from data source 312, scheduler 344, memory 342, transmit processor 320, controller / processor 340, TX MIMO processor 330, transceivers 332a to 332t, antennas 334a to 334t, and / or other aspects described herein. Similarly, “receiving” can refer to various mechanisms that acquire data, such as from antennas 334a to 334t, transceivers 332a to 332t, RX MIMO detector 336, controller / processor 340, receive processor 338, scheduler 344, memory 342, and / or other aspects described herein.

[0085] In various respects, UE 104 can also 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 that output data, such as from data source 362, memory 382, ​​transmit processor 364, controller / processor 380, TX MIMO processor 366, transceivers 354a to 354t, antennas 352a to 352t, and / or other aspects described herein. Similarly, “receiving” can refer to various mechanisms that acquire data, such as from antennas 352a to 352t, transceivers 354a to 354t, RX MIMO detector 356, controller / processor 380, receive processor 358, memory 382, ​​and / or other aspects described herein.

[0086] In some respects, the processor can be configured to perform various operations (such as those associated with the methods described herein) and to send (output) data to or receive data from another interface configured to send or receive data, respectively.

[0087] In various aspects, artificial intelligence (AI) processors 318 and 370 may perform AI processing for BS 102 and / or UE 104, respectively. AI processor 318 may include AI accelerator hardware or circuitry, such as one or more neural processing units (NPUs), one or more neural network processors, one or more tensor processors, one or more deep learning processors, etc. AI processor 370 may similarly include AI accelerator hardware or circuitry. As an example, AI processor 370 may perform AI-based beam management, AI-based channel state feedback (CSF), AI-based antenna tuning, and / or AI-based positioning (e.g., Global Navigation Satellite System (GNSS) positioning). In some cases, AI processor 318 may use hardware-accelerated AI inference and / or AI training to process feedback (e.g., CSF) from UE 104. AI processor 318 may, for example, use hardware-accelerated AI inference associated with the CSF to decode compressed CSF from UE 104. In some cases, AI processor 318 may perform certain RAN-based functions, including, for example, network planning, network performance management, energy-efficient network operation, etc.

[0088] Figure 4A , Figure 4B , Figure 4C and Figure 4D Describes the use of wireless communication networks (such as Figure 1 All aspects of the data structure of the wireless communication network 100.

[0089] Specifically, Figure 4A Figure 400 is an example of the first subframe within a 5G (e.g., 5G NR) frame structure. Figure 4B Figure 430 illustrates an example of a DL channel within a 5G subframe. Figure 4C Figure 450 illustrates an example of the second subframe within a 5G frame structure, and Figure 4D Figure 480 illustrates an example of a UL channel within a 5G subframe.

[0090] Wireless communication systems can utilize Orthogonal Frequency Division Multiplexing (OFDM) with a cyclic prefix (CP) on both the uplink and downlink. Such systems can also support half-duplex operation using Time Division Duplex (TDD). OFDM and Single-Carrier Frequency Division Multiplexing (SC-FDM) will (e.g., as...) Figure 4B and Figure 4D The system bandwidth (as depicted in the text) is divided 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.

[0091] Wireless communication frame structures can be frequency division duplex (FDD), where for a specific set of subcarriers, subframes within that set are dedicated to either deep (DL) or ultra-low (UL). Wireless communication frame structures can also be time division duplex (TDD), where for a specific set of subcarriers, subframes within that set are dedicated to both DL and UL.

[0092] exist Figure 4A and Figure 4C In this example, the wireless communication frame structure is TDD, where D stands for DL, U for UL, and X is flexibly used between DL and UL. The UE can configure the time slot format using the received Time Slot Format Indicator (SFI) (dynamically via DL Control Information (DCI) or semi-statically / statically via Radio Resource Control (RRC) signaling). In the depicted example, a 10ms frame is divided into 10 equal-sized 1ms subframes. Each subframe may include one or more time slots. In some examples, each time slot may include 12 or 14 symbols, depending on the Cyclic Prefix (CP) type (e.g., 12 symbols per time slot for extended CP, or 14 symbols per time slot for regular CP). Subframes may also include micro-time slots, which typically have fewer symbols than the entire time slot. Other wireless communication technologies may have different frame structures and / or different channels.

[0093] In some respects, the number of time slots within a subframe (e.g., the time slot duration within a subframe) is based on a parameter set that defines the frequency-domain subcarrier spacing and symbol duration, as further described herein. In some respects, given a parameter set μ, each subframe has 2 μ The number of time slots is 1. Therefore, parameter sets (µ) 0 through 6 allow for 1, 2, 4, 8, 16, 32, and 64 time slots per subframe, respectively. In some cases, extended CP (e.g., 12 symbols per time slot) can be used with specific parameter sets; for example, parameter set 2 allows for 4 time slots per subframe. Subcarrier spacing and symbol length / duration are functions of the parameter set. The subcarrier spacing can be equal to... kHz, where μ is the parameter set from 0 to 6. As an example, the parameter set... Corresponding to a subcarrier spacing of 15 kHz, and the parameter set This corresponds to a subcarrier spacing of 960 kHz. Symbol length / duration is negatively correlated with subcarrier spacing. Figure 4A , Figure 4B , Figure 4C and Figure 4D It provides a slot format with 14 symbols per slot (e.g., regular CP) and a parameter set with 4 slots per subframe. Example. In this case, the slot duration is 0.25 ms, the subcarrier spacing is 60 kHz, and the symbol duration is approximately 16.67 μs.

[0094] like Figure 4A , Figure 4B , Figure 4C and Figure 4D As depicted, a resource grid can be used to represent the frame structure. Each time slot includes a resource block (RB) (also known as a physical RB (PRB)) extending for, for example, 12 consecutive subcarriers. The resource grid is divided into multiple resource elements (REs). The number of bits carried by each RE depends on the modulation scheme, including, for example, quadrature phase shift keying (QPSK) or quadrature amplitude modulation (QAM).

[0095] like Figure 4A As illustrated in the example, some REs in the RE carry information for the UE (e.g., Figure 1 and Figure 3 The reference (pilot) signal (RS) for the UE (104) may include a demodulation RS (DMRS) and / or a channel state information reference signal (CSI-RS) for channel estimation at the UE. The RS may also include a beam measurement RS (BRS), a beam refinement RS (BRRS), and / or a phase tracking RS (PT-RS).

[0096] Figure 4B Examples of various DL channels within a subframe of a frame are illustrated. The Physical Downlink Control Channel (PDCCH) carries the DCI within one or more Control Channel Elements (CCEs), each CCE comprising, for example, nine RE groups (REGs), each REG comprising, for example, four consecutive REs in an OFDM symbol.

[0097] The Primary Synchronization Signal (PSS) can be located within symbol 2 of a specific subframe of the frame. The PSS is generated by the UE (e.g., Figure 1 and Figure 3 104) is used to determine subframe / symbol timing and physical layer identifier.

[0098] The secondary synchronization signal (SSS) can be located in symbol 4 of a specific subframe of the frame. The SSS is used by the UE to determine the physical layer cell identifier group number and radio frame timing.

[0099] Based on the Physical Layer Identifier and Physical Layer Cell Identifier Group Number, the UE can determine the Physical Cell Identifier (PCI). Based on the PCI, the UE can determine the location of the aforementioned DMRS. The Physical Broadcast Channel (PBCH), carrying the Master Information Block (MIB), can be logically grouped with the PSS and SSS to form a Synchronization Signal (SS) / PBCH block. The MIB provides the System Frame Number (SFN) and the number of Restricted Frames (RBs) in the system bandwidth. The Physical Downlink Shared Channel (PDSCH) carries user data, broadcast system information (such as System Information Blocks (SIBs)) not transmitted via the PBCH, and / or paging messages.

[0100] like Figure 4C As illustrated, some REs in the REs carry DMRS for channel estimation at the base station (indicated as R for a particular configuration, but other DMRS configurations are possible). The UE can transmit DMRS for PUCCH and DMRS for PUSCH. PUSCH DMRS can be transmitted, for example, in the first or second symbol before the PUSCH. PUCCH DMRS can be transmitted in different configurations depending on whether a short or long PUCCH is being transmitted and depending on the specific PUCCH format used. UE104 can transmit a Sounding Reference Signal (SRS). SRS can be transmitted, for example, in the last symbol of a subframe. SRS can have a comb structure, and the UE can transmit SRS on one of the comb teeth. SRS can be used by the base station for channel quality estimation to enable frequency-dependent scheduling of the UL.

[0101] Figure 4D Examples of various UL channels within a subframe of a frame are illustrated. The PUCCH can be located as indicated in one configuration. The PUCCH carries uplink control information (UCI), such as scheduling requests, channel quality indicators (CQI), pre-decoding matrix indicators (PMI), rank indicators (RI), and HARQ ACK / NACK feedback. The PUSCH carries data and may additionally be used to carry buffer status reports (BSR), power clearance reports (PHR), and / or UCI. Various aspects related to backscattering

[0102] Figure 5A An example passive network device 506 is depicted. Passive network device 506 can be a backscatter wireless communication device, such as an A-IoT device or (e.g., with...) Figure 1 (Similar to UE 104) etc.

[0103] As shown in the figure, the passive network device 506 includes an antenna 552, an energy harvesting (EH) circuit 554, a microcontroller 556, a switch 558, and an impedance circuit 560. In other aspects, the passive network device 506 may include additional components (e.g., a battery or capacitor) or fewer components (e.g., removing the EH circuit 554).

[0104] Antenna 552 can be similar to Figure 3 Antenna 352a. Antenna 552 is coupled to EH circuit 554 and impedance circuit 560. EH circuit 554 may include one or more power converters, etc., for receiving (e.g., RF) energy and converting it into usable energy for passive network device 506. EH circuit 554 is also coupled to microcontroller 556. In other respects, microcontroller 556 may be directly coupled to antenna 552.

[0105] The microcontroller 556 is coupled to the switch 558 and configured to control the switch 558 in response to an impedance circuit 560. The impedance circuit 560 can be any component that provides impedance.

[0106] Figure 5A The wireless communication device 501 is further described, such as a network entity (e.g., a BS, such as...). Figure 1 The wireless communication device 501 also includes antennas 534a and 534b, which can be similar to BS 102) or RF entities, etc. Figure 3 Antennas 334a and 334t.

[0107] In some respects, the wireless communication device 501 is configured to transmit a carrier wave from the antenna 534a. The carrier wave is a waveform (e.g., a sine wave) that can be modulated using data (e.g., an information-carrying signal) to generate a modulated signal that transmits the data.

[0108] In some respects, passive network device 506 is configured to receive a carrier wave transmitted by wireless communication device 501 at antenna 552. Passive network device 506 modulates the carrier wave by switching switch 558 to change the impedance coupled to antenna 552. Specifically, switch 558 changes the impedance by switching the number or size of impedance circuits 560 coupled to antenna 552. Changing the impedance coupled to antenna 552 causes a change in the amplitude and / or phase of the carrier wave. For example, when antenna 552 is coupled to a high impedance, the mismatch between the antenna and the load impedance will reflect all the power received at antenna 552 back. When antenna 552 is coupled to an impedance that matches the antenna impedance, the matching between the antenna and the load impedance causes power to be absorbed at passive network device 506 and a small amount of power to be reflected at antenna 552. Therefore, switching between high and matched impedances modulates the amplitude of the reflected carrier wave. The switching frequency between impedances can be associated with the data rate transmitting data.

[0109] Microcontroller 556 controls switch 558 to modulate a carrier wave using data, thereby generating a modulated backscattered signal. For example, microcontroller 556 controls switch 558 to perform amplitude shift keying (ASK) (e.g., on / off keying (OOK)), modulation to change the amplitude of the carrier wave, and / or phase shift keying (PSK) modulation to change the phase of the carrier wave. Passive network device 506 transmits (e.g., backscattered) the modulated signal via antenna 552.

[0110] In some respects, the wireless communication device 501 is configured to receive a modulated backscattered signal on antenna 534b. The wireless communication device 501 can process the modulated backscattered signal to decode data transmitted by the passive network device 506.

[0111] Figures 5B to 5F An example deployment scenario for the passive network device 506 is described.

[0112] Figure 5B A single-site deployment scenario is depicted, in which the passive network device 506 is configured to communicate with the same wireless communication device 561 (e.g., such as...). Figure 5A The wireless communication device 501 receives a carrier wave and backscatters a modulated signal back to itself. For example, the wireless communication device 561 may be capable of full-duplex communication. As shown, the wireless communication device 561 sends a signal to the passive network device 506, which serves as both a carrier wave and a forward link signal carrying control signaling. The passive network device 506 modulates and backscatters this signal as a reverse link signal carrying data. In some respects, the carrier wave and the forward link signal are transmitted separately.

[0113] Figures 5C to 5F Different dual-site deployment scenarios are described, in which the passive network device 506 is configured to receive a carrier from one device and backscatter the modulated signal to different devices, such as those used for half-duplex communication.

[0114] Figure 5C An example is shown where a passive network device 506 is configured to access BS 562 (e.g., Figure 1 In a scenario where BS 102 receives a signal used as both a carrier and a forward link signal, passive network device 506 modulates this signal as a reverse link signal carrying data and backscatters it to UE 564 (e.g., ...). Figure 1 (UE 104). In some respects, the carrier and forward link signals can be transmitted separately.

[0115] Figure 5D An example is illustrated where passive network device 506 is configured to receive a signal from UE 564 that serves as both a carrier and a forward link signal. Passive network device 506 modulates this signal as a reverse link signal carrying data and backscatters it to BS 562. In some respects, the carrier and forward link signals can be transmitted separately.

[0116] Figure 5E This illustrates a scenario where passive network device 506 is configured to receive a carrier from BS 562. Passive network device 506 modulates the carrier signal as a reverse link signal carrying data and backscatters it to UE 564. Passive network device 506 further receives forward link signals from UE 564.

[0117] Figure 5FThis illustrates a scenario where passive network device 506 is configured to receive a carrier from UE 564. Passive network device 506 modulates the carrier signal as a reverse link signal carrying data and backscatters it to BS 562. Passive network device 506 further receives a forward link signal from BS 562. Various aspects related to synchronization of passive network devices

[0118] Wireless communication networks (such as) Figure 1 The wireless communication network 100 may include various communication devices, such as those used with one or more passive network devices (e.g., Figure 5A Passive network devices 506, such as Figure 1 Network entities that communicate with BS 102 or UE 104 (e.g., BS 102 or UE 104) and / or one or more other network devices (e.g., Figure 5A Wireless communication devices 501, BS (such as Figure 1 Examples include BS 102, etc. To optimize the service performance and reliability of communications in a wireless communication network (e.g., to prevent interference and associated service loss), downlink and / or uplink synchronization can be performed to synchronize transmission timing between network devices.

[0119] To achieve synchronization between network entities in a network and one or more passive network devices (e.g., those capable of asynchronous communication only in conventional implementations), the aspects described herein introduce configurable bilateral preambles. Bilateral preambles may include: (1) a first preamble (also referred to as a "preamble sent by the network entity" or "RF preamble") sent by the network entity or radio frequency (RF) entity to the passive network device for downlink synchronization and, in some cases, to assist uplink synchronization; and (2) a second preamble (also referred to as a "preamble sent by the passive network device") sent by the passive network device to the network entity for uplink synchronization. The first preamble may be configurable such that, in some cases, the first preamble is disabled and only the second preamble is sent. In other cases, both the first and second preambles are sent.

[0120] Figures 6 to 9 Various scenarios for synchronization using configurable two-sided preambles are described. For example, the following is described in detail. Figure 6 and Figure 7 A scenario is depicted in which both a first preamble and a second preamble are used to synchronize communication between a network entity and a passive network device. Specifically, the first preamble is sent by the network entity or RF entity, and based on the passive network device's reception of the first preamble, the passive network device sends a backscattered signal including the second preamble. Figure 6 In the first part, the preamble is sent by the network entity, while... Figure 7In this process, the first preamble is sent by the RF entity.

[0121] Alternative locations, described in detail below. Figure 8 and Figure 9 A scenario is depicted in which only a second preamble (e.g., the first preamble is disabled) is used to synchronize communication between a network entity and a passive network device. Specifically, the WUS (e.g., instead of the first preamble) is transmitted by the network entity or RF entity, and based on the passive network device's reception of the WUS, the passive network device transmits a backscattered signal including the second preamble. Figure 8 In the middle, WUS is sent by network entities, while... Figure 9 In this process, the first preamble is sent by the RF entity. In a communication network for synchronizing passive network devices using both a first preamble and a second preamble Example operations for entities

[0122] Figure 6 A process flow 600 for communication between network entity 602 and passive network device 604 in a network is described. In some aspects, network entity 602 may be related to... Figure 1 and Figure 3 The BS 102 described and depicted, regarding Figure 2 The decomposed BS described and illustrated, or about Figure 1 and Figure 3 The example of UE 104 depicted and described. Similarly, passive network device 604 can be about... Figure 1 and Figure 3 The UE 104 depicted and described or about Figure 1 and Figure 3 Examples of BS 102 depicted and described herein. However, in other respects, passive network device 604 may be another type of passive wireless communication device, and network entity 602 may be another type of network entity or network node, such as those described herein.

[0123] As described above, Figure 6 Process flow 600 describes the use of both a first preamble (e.g., a preamble sent by the network entity) and a second preamble (e.g., a preamble sent by the passive network device) to achieve uplink and downlink synchronization between network entity 602 and passive network device 604. For example, as Figure 6 As shown, network entity 602 sends a first preamble 614 to passive network device 604. The first preamble 614 may be sent in one or more first symbols. Network entity 602 may send a first frequency. The first preamble 614 is transmitted. In some respects, network entity 602 broadcasts the first preamble 614. Therefore, the first preamble 614 can be received and backscattered by multiple passive network devices, including passive network device 604.

[0124] Network entity 602 may transmit the first preamble 614 if downlink synchronization is required between network entity 602 and passive network device 604 (e.g., network entity 602 enables the first preamble 614). Alternatively, network entity 602 may transmit the first preamble 614 if downlink synchronization is not required (e.g., enable the first preamble 614); however, the carrier also transmitted by network entity 602 (e.g., such as...) Figure 6 The carriers 620(1) to 620(3) in (1) are modulated using other information, or (2) have a complex waveform similar to OFDM. Specifically, as described in detail below, the transmission of the first preamble 614 allows network entity 602 to measure the round-trip time (RTT) from when the first preamble 614 is transmitted to passive network device 604 until the first preamble 614 is received from passive network device 604 as a first backscattered signal 616 (e.g., reflected by the passive network device). The RTT can be used by network entity 602 to remove the carrier from the backscattered signal from passive network device 604 in order to demodulate with lower search complexity. For example, network entity 602 can use the RTT to help decode the second backscattered signal 618 (including the second preamble) transmitted from passive network device 604 to network entity 602 (also described in detail below).

[0125] In some respects, network entity 602 sends a first preamble 614 to initiate an initial access procedure, for example, between network entity 602 and passive network device 604. The initial access procedure (i.e., random access procedure) is a process designed to obtain initial uplink permission for passive network device 604 and to facilitate synchronization between passive network device 604 and network entity 602.

[0126] In some respects, network entity 602 sends a first preamble 614 to passive network device 604 after the initial access procedure is completed (e.g., when passive network device 604 is using a fixed frequency instead of a random frequency shift). For example, in some cases, network entity 602 sends the first preamble 614 to passive network device 604 after a periodic timer expires, which may have been started after the initial access procedure between network entity 602 and passive network device 604 is completed. As an illustrative example, the timer may have been started and is expected to run after the initial access procedure is completed. X Milliseconds. This has been elapsed since the initial access process was completed. XAfter milliseconds, network entity 602 may send a first preamble 614. In some other cases, network entity 602 sends the first preamble 614 to passive network device 604 after determining that the uplink communication from passive network device 604 deviates from the expected time and / or frequency of the uplink communication by at least a threshold amount. In other words, network entity 602 may send the preamble 614 when the timing and / or frequency synchronization deviation detected by network entity 602 is greater than the threshold amount. In some other cases, network entity 602 sends the first preamble 614 to passive network device 604 after detecting a frequency shift in the uplink communication from passive network device 604. For example, passive network device 604 may change the frequency shift value through configuration by network entity 602 or self-determination. In some other cases, network entity 602 sends an indication to passive network device 604 that is intended only for use by passive network device 604 (e.g., a dedicated indication). In this case, network entity 602 sends a first preamble 614 to passive network device 604 after sending the instruction.

[0127] In some respects, before sending the first preamble 614 to the passive network device 604, the network entity 602 sends WUS 612 to the passive network device 604. Specifically, to conserve power, the passive network device 604 may be in a sleep state. The transmission of WUS 612 acts as an indicator for the passive network device 604, instructing it to wake up from its sleep state (e.g., transition to an awake state) and monitor the first preamble 614. Figure 6 In the example illustrated, WUS 612 indicates (e.g., by network entity 602) that the transmission of the first preamble 614 is enabled.

[0128] In some respects, WUS 612 is a WUS dedicated to passive network device 604 (e.g., WUS 612 is a dedicated waveform intended only for passive network device 604 and not for multiple passive network devices), specifically designed to wake up passive network device 604 to monitor the first preamble 614. Therefore, based on receiving the WUS 612 dedicated to passive network device 604, passive network device 604 can wake up and monitor the first preamble 614.

[0129] In some other respects, WUS 612 is not a WUS dedicated solely to passive network device 604. Instead, WUS 612 is sent to / intended for use by multiple passive network devices. Multiple passive network devices, including passive network device 604, can receive WUS 612 indicating wake-up and monitoring of a first preamble 614. If all passive network devices receiving WUS 612 are to wake up simultaneously (or nearly simultaneously) and begin monitoring the first preamble 614, all passive network devices will send backscatter signals 616 to network entity 602 after simultaneously (or nearly simultaneously) receiving the first preamble 614 (e.g., based on monitoring). Unfortunately, this can lead to one or more conflicts between the backscatter signals 616 sent by the passive network devices. Therefore, network entity 602 may be unable to identify which first backscatter signal belongs to which passive network device, thus making it impossible to calculate the RTT required to determine the specific timing information used for synchronization with each particular passive network device. Therefore, in order to reduce the collision of backscattered signals sent to network entity 602, this paper describes different options for non-dedicated WUS (e.g., WUS not intended for use with a single passive network device).

[0130] For example, in the first option, the passive network device, including passive network device 604, determines to randomly wake up and monitors the preamble. Specifically, passive network device 604 may receive multiple WUS (including WUS 612) sent by network entity 602. Passive network device 604 may determine one of the multiple WUS to respond to through a random process. Figure 6 In the example illustrated, passive network device 604 determines its response to WUS 612 through a random process. Therefore, passive network device 604 wakes up based on receiving WUS 612 and monitors the first preamble 614. Although not shown, passive network device 604 may also receive other WUS, randomly determine not to respond to those WUS, and thus remain in a sleep state after receiving those other WUS.

[0131] Alternatively, in a second option, passive network devices, including passive network device 604, are each assigned to a single group among multiple groups (e.g., passive network device 604 is assigned to group 1, another passive network device is assigned to group 2, etc.), where each group is assigned a group index. The WUS 612 sent by network entity 602 may include an indication of the group index, and passive network devices belonging to the group associated with that group index may wake up and monitor the first preamble 614, while other passive network devices remain asleep and await another WUS including a group index associated with the group to which those passive network devices belong.

[0132] Figure 10Example scenario 1000 is provided to illustrate how this type of group-specific WUS works. For example... Figure 10 As shown, (for example, with) Figure 6 Network entity 1002 (similar to network entity 602 in the previous example) sends multiple WUS (e.g., including WUS 1020 and WUS 1030) and multiple first preambles (e.g., including first preamble 1022 and first preamble 1032). WUS 1020 and 1030 may not be intended for use with a particular passive network device; therefore, including (e.g., with) Figure 6 Several passive network devices, including passive network device 1004 (similar to passive network device 604), can receive WUS 1020 and / or WUS 1030.

[0133] In this example, ten passive network devices, including passive network device 1004, receive WUS 1020 (although the remaining nine passive network devices are not shown in this example). Three of the ten passive network devices may belong to (e.g., previously assigned to) Group 1, three of the ten passive network devices (including passive network device 1004) may belong to Group 2, and the remaining four of the ten passive network devices may belong to Group 3. Therefore, in this example, there are three groups (e.g., the number of groups ( N ) =3 ), where the first group and the group index n =1 Related, second group and group index n=2 Related, and the third group is associated with the group index. n=3 Related.

[0134] Based on the use of the second set of indexes n=2 To pre-configure the passive network device 1004 (e.g., based on the passive network device 1004 being pre-configured to receive a group index). n=2 After monitoring the preamble (WUS), passive network device 1004 may belong to the second group. In some other cases, passive network device 1004 belongs to the second group based on the random access radio network temporary identifier (RA-RNTI) (e.g., special RA-RNTI) assigned to passive network device 1004, where the RA-RNTI is indexed to the second group. n=2 Related. For example, the value of RA-RNTI received by RA-RNTI can be equal to ( 10n+k ), of which (1) n Upon receiving a specified n After WUS, the passive network device 1004 is expected to target a specific group index for its wake-up and monitoring of the preamble, and (2) kIt is an index of a specific frequency shift that the passive network device 1004 is expected to use when transmitting backscattered signals (described in more detail below).

[0135] Network entity 1002 may determine that a first preamble 1022 will be sent, and before sending the first preamble 1022, sends WUS 1020 to wake up passive network devices and monitor the first preamble 1022 from network entity 1002. To help reduce the number of passive network devices that can receive the first preamble 1022 and respond to it (e.g., via the transmission of a backscattered signal), WUS 1020 includes a first set of indices. n=1 The first set of indexes is included in WUS 1020. n=1 This allows receiving WUS 1020 and belonging to the first group (e.g., with the first group index). n=1 Three passive network devices (associated with) are woken up, while the remaining seven passive network devices that receive WUS 1020 and belong to the second and third groups remain in sleep mode.

[0136] For example, since WUS 1020 includes the first set of indexes n=1 Instead of the second set of indexes n=2 Therefore, the passive network device 1004 can remain in a sleep state when it receives WUS 1020. The passive network device 1004 can then wait for the next WUS and determine whether the next received WUS includes the second set of indices. n=2 .

[0137] For example, after sending WUS 1020, network entity 1002 sends WUS 1030. The time gap between the transmission of WUS 1020 and the transmission of WUS 1030 can be used for network entity 1002 to send the first preamble 1022, for network entity 1002 to sense the backscattered signal from the passive network device, and for the passive network device to send the backscattered signal. WUS 1030 includes a second set of indexes. n=2 The second set of indexes is included in WUS 1030. n=2 It can wake up passive network device 1004 together with other passive network devices belonging to the second group and receiving WUS 1020 and monitor the first preamble 1032.

[0138] In this way, the passive network device 1004 can ( 1 / N The probability of transitioning to a conscious state (e.g., "on") and with ( 1- ( 1 / N)The probability of the passive network device 1004 remaining in a sleep state (e.g., "off") is 33.33% (e.g., 1 / 3 group = 33.33%) during the time WUS is transmitted, and the probability of remaining in a sleep state during the time WUS is transmitted is 66.66% (e.g., 1 - (1 / 3 group) = 66.66%).

[0139] return Figure 6 The transmission of the first preamble 614 is received by the passive network device 604. Using the passive radio equipment at the passive network device 604, the passive network device 604 reflects the first preamble 614 as a first backscatter signal 616. In other words, the passive network device 604 transmits the first backscatter signal 616 to the network entity 602 based on the first preamble 614.

[0140] Passive network device 604 can operate on a second frequency. Send a first backscatter signal 616, the second frequency of which is equal to: in The first frequency used by network entity 602 to transmit the first preamble 614, and f It's a frequency shift. In some respects, a frequency shift is configured at 604 of the passive network device. f In some respects, frequency shift f The frequency shift is randomly selected by the passive network device 604 from a set of frequency shift values ​​pre-configured at the passive network device 604. In some respects, the frequency shift value... f Based on the RA-RNTI assigned to the passive network device 604 (e.g., a specific RA-RNTI). For example, as described above, the value of the RA-RNTI assigned to the passive network device 604 may be equal to ( 10n+k ), of which (1) n Passive network device 604 receives a specified n After WUS, it is expected to target specific group indices for its wake-up and monitoring of the preamble, and (2) k This is an index of a specific frequency shift that the passive network device 604 is expected to use when transmitting backscattered signals. The passive network device 604 uses the frequency shift index included in association with RA-RNTI. k To identify the frequency shift to be used by the passive network device 604 f (e.g., frequency shift index) k With a specific frequency shift f (Associated). Based on relative to the first frequency. frequency shift Δf Sending the first backscatter signal 616 can (1) help avoid conflicts between the first backscatter signal 616 and other backscatter signals sent by other passive network devices; and / or (2) help network entity 602 determine the frequency compensation required for uplink synchronization (as described in detail below).

[0141] The reception of the first preamble 614 by the passive network device 604 can not only cause the passive network device 604 to reflect the first preamble 614 (e.g., using the first preamble as a first backscatter signal 616), but also trigger the passive network device 604 (e.g., via backscatter) to transmit a second preamble. The transmission of the second preamble can be used (e.g., configured for) synchronization of uplink communication between network entity 602 and the passive network device 604. In some respects, the second preamble is a RACH preamble, a simplified RACH preamble, or another type of preamble. The passive network device 604 can transmit the second preamble based on a timing offset 628 configured at the passive network device 604, wherein, in this case, the timing offset 628 is the time period during which the passive network device 604 expects to wait between receiving the first preamble 614 and transmitting the second preamble.

[0142] In some respects, the timing offset 628 configured at the passive network device 604 is based on the position of one or more first symbols used to transmit the first preamble 614. For example, a shorter timing offset 628 can be configured at the passive network device 604 if the first preamble 614 is transmitted by the network entity 602 at the end of a time slot, and a longer timing offset 628 can be configured at the passive network device 604 if the first preamble 614 is transmitted by the network entity 602 at the beginning of a time slot. Furthermore, a shorter timing offset 628 can be configured at the passive network device 604 if the carrier 620 transmitted by the network entity 602 is transmitted at the beginning of a different time slot, contrary to the case where the carrier 620 transmitted by the network entity 602 is transmitted at the end of a different time slot. This helps to avoid transmitting a second preamble across two time slots (e.g., thus avoiding the second preamble from affecting the frame structure). Furthermore, in some respects, one or more first symbols used by network entity 602 to transmit the first preamble 614 are time-slot symbols and do not include the last symbol in that time slot, for example, to similarly avoid the passive network device 604 transmitting the second preamble across two time slots. In some respects, if the timing offset 628 is very large, network entity 602 may use an extended cyclic prefix (CP) for the OFDM-based carrier. The extended CP adds an additional guard period between symbols and thus reduces the number of symbols in a time slot. Given that the symbols are actually wider in time, using the extended CP helps the passive network device 604 receive signals at the correct symbol time position.

[0143] In some respects, timing offset 628 is defined within WUS 612, which is transmitted to passive network device 604. WUS 612 may additionally include an indication of a symbol index (e.g., an OFDM symbol index in a time slot) for the start symbol in one or more first symbols used to transmit the first preamble 614. This helps to keep the backscattered signal within a single time slot, making it compatible with frame structures (e.g., NR frame structures).

[0144] For example, in response to receiving a first preamble 614, passive network device 604 transmits a second backscatter signal 618. The second backscatter signal 618 includes a second preamble configured for synchronization of uplink communication between network entity 602 and passive network device 604. Passive network device 604 may randomly select a second preamble included in the second backscatter signal 618 from a set of available preambles in response to receiving the first preamble 614. Passive network device 604 transmits the second backscatter signal 618 including the second preamble based on a carrier 620 (e.g., specifically, carrier 620(3)) received from network entity 602.

[0145] Specifically, as described above, carrier 620(3) is a waveform (e.g., a sine wave) that can be modulated using data (e.g., an information-bearing signal) to generate a modulated signal for transmitting that data. Network entity 602 transmits carrier 620(3) so that passive network device 604 can modulate the data on the carrier (e.g., modulate a second preamble) and provide the second preamble to network entity 602. Specifically, passive network device 604 uses its passive radio equipment to reflect the carrier 620(3) received from network entity 602 (e.g., reflect the carrier as a second backscatter signal 618) and modulates the second preamble in the reflection to transmit the second preamble to network entity 602 for uplink synchronization. Passive network device 604 switches passive network device 604's switches (e.g., such as...) Figure 5A (Switch 558) to enable the antenna (e.g., such as) coupled to the passive network device 604. Figure 5A The impedance of the antenna 552 is changed to modulate the carrier 620(3).

[0146] Similar to the previous transmission of the first backscatter signal 616, the passive network device 604 can transmit at a second frequency. Send the second backscatter signal 618. Again, use the second frequency. (This second frequency is based on the first frequency) frequency shift f Sending the second backscatter signal 618 can help (1) avoid conflicts between the second backscatter signal 618 and other backscatter signals sent by other passive network devices, and / or (2) help network entity 602 determine the frequency compensation required for uplink synchronization (as described in detail below).

[0147] Passive network device 604 transmits a second backscatter signal 618, including a second preamble, to network entity 602 in one or more second symbols. The one or more second symbols are offset in time relative to the one or more first symbols used by network entity 602 to transmit the first preamble 614 by (1) a timing offset 628 configured at passive network device 604 and (2) a timing error offset 630 of passive network device 604. In other words, the time of transmitting the second backscatter signal 618 (e.g., T tx_2ndpreamble ) and the time of receiving the first preamble 614 (e.g., T rx_1stpreamble The difference between the two is equal to the sum of the timing offset 628 and the timing error offset 630, which is given by the following equation: )

[0148] Passive network device 604 is intended to transmit a second backscatter signal 618 including a second preamble according to a timing offset 628 configured at passive network device 604 and to assume that it is transmitting the second backscatter signal; however, due to clock errors / skew at passive network device 604, passive network device 604 may actually transmit the backscatter signal 618 later in time. This additional time due to clock errors / skew at passive network device 604 is referred to herein as "timing error offset".

[0149] like Figure 6 As shown, network entity 602 receives both a first backscattered signal 616 and a second backscattered signal 618 (e.g., with a second preamble) from passive network device 604. Network entity 602 calculates the RTT 626 of the first preamble 614 as the time of receiving the first backscattered signal 616 (e.g., a reflection of the first preamble 614). T rx_1stbackscatter ) and the time of sending the first preamble 614 (e.g., T tx_1stpreamble The difference between them is given by the following equation:

[0150] Network entity 602 uses the calculated RTT 626 to decode the second backscattered signal 618, which includes the second preamble. In other words, network entity 602 uses the calculated RTT 626 to remove the carrier 620(3) (e.g., OFDM).

[0151] Furthermore, at 624, network entity 602 uses the calculated RTT 626, the timing offset 628 configured at passive network device 604, and the time at which the first backscatter signal 616 (e.g., reflection of the first preamble 614) is received (e.g., T rx_1stbackscatter The time between receiving (e.g., including the second preamble) the second backscattered signal 618 (e.g., T rx_2ndpreamble The timing advance (TA) 622 is calculated using the following formula: TA 622 represents the timing compensation required for uplink synchronization. TA 622 can be calculated using the following equation: Where RTT equals the RTT 626 calculated above, and the timing error offset 630 is calculated according to the following equation: Or choose another location:

[0152] In addition to calculating TA 522 (e.g., the required timing compensation for uplink synchronization), network entity 602 can also determine the required frequency compensation 627 for uplink synchronization at 624. For example, the required frequency compensation 627 can be calculated according to the following equation: in It is a first frequency used to send the first preamble 614 to the passive network device 604, wherein It is a second frequency used to send the first backscatter signal 616 and / or the second backscatter signal 618 to network entity 602, and This is the frequency shift amount configured at 604 of the passive network device. In some cases, the frequency shift configured at 604 of the passive network device... The frequency shift that is not actually used by the passive network device 604 to transmit the first backscatter signal 616 and / or the second backscatter signal 618 f (For example, due to the low clock accuracy of the passive network device 604). The difference between the configured frequency shift and the frequency shift used to transmit the backscatter signal 616 and / or the second backscatter signal 618 is determined via the frequency compensation equation described above.

[0153] In some respects, TA 622 and / or frequency compensation 627 are used to control the uplink transmission timing and / or frequency of subsequent uplink communication sent by passive network device 604 to network entity 602, respectively. In other words, passive network device 604 can use TA 622 and / or frequency compensation 627 to synchronize with passive network device 602. When the carrier 620 transmitted by network entity 602 is an ambient carrier (e.g., not a dedicated waveform intended solely for passive network device 604 and receivable by other passive network devices), passive network device 604 can be synchronized with network entity 602 (the opposite of network entity 602 synchronizing with passive network device 602) when the timing resolution capability of passive network device 604 is less than or equal to half of TA 622 (e.g., the required timing compensation) (e.g., timing resolution capability ≤ TA / 2) and the frequency shift capability of passive network device 604 is less than or equal to frequency compensation 627 (e.g., frequency shift capability ≤ frequency compensation / 2).

[0154] For example, network entity 602, which transmits ambient carrier waves, may allow one or more passive network devices to synchronize with it. Therefore, when network entity 602 is also attempting to synchronize with other passive network devices, it may be unable to synchronize with passive network device 604.

[0155] Furthermore, the passive network device 604 may (e.g., via backscatter signaling) send its timing resolution capability and / or frequency shift capability to the network entity 602. The timing resolution capability of the passive network device 604 may represent the smallest unit of time that the passive network device 604 can control, while the frequency shift capability of the passive network device 604 may represent the smallest unit of frequency that the passive network device 604 can control.

[0156] Passive network device 604 may provide one or both of these capabilities after detecting network entity 602 and / or in response to a query from network entity 602 requesting such capability information. When the timing resolution capability of passive network device 604 is provided to network entity 602, network entity 602 compares the timing resolution capability of passive network device 604 with TA 622. For example, passive network device 604 may be able to control time as small as 1 millisecond (ms). The TA 622 calculated by network entity 602 may be equal to 40ms. Therefore, when comparing the timing resolution capability of passive network device 604 with TA 622 (e.g., 1ms < (40ms / 2)), network entity 602 can determine that passive network device 604 can compensate for a 40ms TA, meaning that passive network device 604 can be synchronized with network entity 602. Furthermore, when the frequency shift capability of the passive network device 604 is provided to the network entity 602, the network entity 602 compares the frequency shift capability of the passive network device 604 with the frequency compensation 627.

[0157] Alternatively, if the carrier 620 transmitted by network entity 602 is not an ambient carrier (e.g., instead, carrier 620 is a dedicated waveform intended only for use with passive network device 604), the timing resolution capability of passive network device 604 is greater than TA 622 (e.g., timing resolution capability > TA / 2), or the frequency shift capability of passive network device 604 is greater than frequency compensation 627 (e.g., frequency shift capability > frequency compensation / 2), then network entity 602 may synchronize with passive network device 604.

[0158] It should be noted that, given that network entity 604 may only need to synchronize with passive network device 604 if the timing resolution capability of passive network device 604 is greater than that of TA622, in which case network entity 604 may send carrier 620 which is not an ambient carrier (e.g., carrier 620 is a special waveform intended only for use with passive network device 604).

[0159] When network entity 602 determines that passive network device 604 will synchronize with network entity 602, network entity 602 sends TA 622 and / or frequency compensation 627 to passive network device 604. Passive network device 604 uses TA 622 and / or frequency compensation 627 to control the uplink transmission timing and / or frequency of subsequent uplink communications sent by passive network device 604 to network entity 602.

[0160] Alternatively, if network entity 602 determines that it needs to synchronize with passive network device 604, it may not be necessary to send TA 622 and / or frequency compensation 627 to passive network device 604. Network entity 602 may use TA 622 and / or frequency compensation 627 when receiving subsequent uplink communication from passive network device 604. Furthermore, network entity 602 may use TA 622 and / or frequency compensation 627 when transmitting carrier 620.

[0161] Figure 7 A process flow 700 is described for communication between network entity 702, passive network device 704, and RF entity 706 in a network. In some aspects, network entity 702 may be related to... Figure 1 and Figure 3 The BS102 described and depicted, regarding Figure 2 The decomposed BS described and illustrated, or about Figure 1 and Figure 3 The example of UE 104 depicted and described. Similarly, passive network device 704 can be related to... Figure 1 and Figure 3 The UE 104 depicted and described or about Figure 1 and Figure 3 Examples of BS 102 depicted and described. In some respects, RF entity 706 may be about Figure 1 and Figure 3 The BS 102 described and depicted, regarding Figure 2 The decomposed BS described and illustrated, regarding Figure 1 and Figure 3 Examples of UE 104, or IAB nodes, depicted and described herein. However, in other respects, passive network device 704 may be another type of passive wireless communication device, and network entity 702 and / or RF entity 706 may be another type of network entity or network node, such as those described herein.

[0162] As described above, Figure 7The process flow 700 describes the use of both a first preamble (e.g., a preamble sent by the RF entity) and a second preamble (e.g., a preamble sent by the passive network device) to achieve uplink and downlink synchronization between network entity 702 and passive network device 704. However, with Figure 6 different, Figure 7 The process flow 700 describes a scenario in which the first preamble is sent by RF entity 706 instead of network entity 702.

[0163] For example, such as Figure 7 As shown, RF entity 706 sends optional WUS 712, carrier 720, and first preamble 714 to passive network device 704, which can be similar to those described above for... Figure 6 The optional WUS 612, carrier 620, and first preamble 614 described in process flow 600 are transmitted by RF entity 706 rather than network entity 702, although such signaling is transmitted by RF entity 706 rather than network entity 702. However, the first backscatter signal 716 and the second backscatter signal 718 received by network entity 702 can be similar to those in... Figure 6 The first backscattered signal 616 and the second backscattered signal 618 are received by network entity 602. Furthermore, the variables used to calculate TA 722 at 724 (e.g., RTT 726, timing offset 728, and timing error offset 730) can be similar to those in... Figure 6 The variable used to calculate TA 622 at position 624. However, in order to calculate RTT 726, network entity 702 determines the time when the first preamble 714 was sent by RF entity 706 based on previous communication between network entity 702 and RF entity 706 (e.g., T tx_1stpreamble For example, prior communication between RF entity 706 and network entity 702 may have taken place to coordinate between them. Therefore, it can be assumed that network entity 702 is aware of when the first preamble 714 was sent by RF entity 706 (e.g., T tx_1stpreamble ).

[0164] Additionally, similar to in Figure 6 The frequency compensation of 627 is calculated at position 624, and the frequency compensation of 727 can be calculated at position 724. Example operations for entities in a communication network that use only the second preamble for passive network device synchronization.

[0165] Figure 8 A process flow 800 for communication between network entity 802 and passive network device 804 in a network is described. In some aspects, network entity 802 may be related to... Figure 1 and Figure 3The BS 102 described and depicted, regarding Figure 2 The decomposed BS described and illustrated, or about Figure 1 and Figure 3 The example depicted and described is UE 104. Similarly, passive network device 804 can be about... Figure 1 and Figure 3 The UE 104 depicted and described or about Figure 1 and Figure 3 Examples of BS 102 depicted and described herein. However, in other respects, passive network device 804 may be another type of passive wireless communication device, and network entity 802 may be another type of network entity or network node, such as those described herein.

[0166] As described above, Figure 8 The process flow 800 describes the use of only a single preamble (e.g., a second preamble in a configurable dual-sided preamble or a preamble sent by a passive network device) to achieve uplink synchronization between network entity 802 and passive network device 804. This is consistent with the above description. Figure 6 Process flow 600 and Figure 7 The process flow is different from 700. Further details are provided below. Figure 6 Process flow 600 and Figure 7 Unlike process flow 700, passive network device 804 is triggered to send a second preamble based on the received WUS (e.g., WUS 814) instead of the first preamble (given that only one preamble is sent). Figure 8 In this context, it is referred to as the "preamble".

[0167] For example, such as Figure 8 As shown, network entity 802 sends WUS 814 to passive network device 804 in one or more first symbols. Similar to... Figure 6 The first preamble 614 and Figure 7Upon transmission of the first preamble 714, network entity 802 may send WUS 814 to initiate an initial access procedure. In some other cases, network entity 802 sends WUS 814 after the initial access procedure is completed. For example, network entity 802 may send WUS 814 to passive network device 804 after a periodic timer expires, which may have been started after the initial access procedure between network entity 802 and passive network device 804 is completed. In some other examples, network entity 802 sends WUS 814 to passive network device 804 after determining that uplink communication from passive network device 804 deviates from the expected time and / or frequency of uplink communication by at least a threshold amount. In some other cases, network entity 802 sends an indication to passive network device 804 that is intended solely for use by passive network device 804 (e.g., a dedicated indication). In this case, network entity 802 sends WUS 814 to passive network device 804 after sending this indication.

[0168] To conserve power, the passive network device 804 can be in a sleep state. The transmission of WUS 814 acts as an indicator for the passive network device 804, instructing it to wake from sleep (e.g., transition to wakefulness). WUS 814 can be similar to... Figure 6 WUS 612 and Figure 7 The WUS 712; however, unlike the WUS 612 and 712, Figure 8 WUS 814 in the passive network device 804 can (1) indicate that the transmission of the first preamble 614 is disabled and (2) trigger the passive network device 804 to transmit the preamble (e.g., via backscatter). The transmission of the preamble can be used (e.g., configured for) synchronization of uplink communication between network entity 802 and passive network device 804. Passive network device 804 can transmit the second preamble based on a timing offset 828 configured at passive network device 804, wherein, in this case, timing offset 828 is the period of time that passive network device 804 expects to wait between receiving WUS 814 and transmitting the preamble. Timing offset 828 can be similar to Figure 6 The timing offset is 628 and Figure 7 The timing offset is 728, the difference is... Figure 8 The timing offset 828 in the text represents the time period between receiving WUS 814 and sending the preamble, not the time period between receiving the first preamble and sending the second preamble.

[0169] Passive network device 804 transmits a preamble (e.g., based on received WUS 814) by transmitting a first backscatter signal 818. Specifically, passive network device 804 transmits the first backscatter signal 818, which includes a second preamble, based on one of received carriers 820(1) to 820(3) (e.g., specifically, carrier 820(3) from network entity 802). For example, passive network device 804 uses its passive radio equipment to reflect the carrier 820(3) received from network entity 802 (e.g., using that carrier as the first backscatter signal 818) and modulates the preamble in the reflection to convey the second preamble to network entity 802 for uplink synchronization. Passive network device 804 may randomly select the second preamble included in the first backscatter signal 818 from the set of available preambles in response to received WUS 814.

[0170] Passive network device 804 transmits a first backscatter signal 818, including a preamble, to network entity 802 in one or more second symbols. The one or more second symbols are offset in time relative to one or more first symbols used by network entity 802 to transmit WUS 814 by (1) a timing offset 828 configured at passive network device 804 and (2) a timing error offset 830 of passive network device 804.

[0171] Passive network device 804 may be intended to transmit a first backscattered signal 818 including a second preamble according to a timing offset 828 configured at passive network device 804 and to assume that it is transmitting the first backscattered signal; however, due to clock errors / skew at passive network device 804, passive network device 804 may actually transmit the backscattered signal 818 later in time. This additional time due to clock errors / skew at passive network device 804 is referred to herein as the "timing error offset".

[0172] like Figure 8 As shown, network entity 802 receives a first backscatter signal 818 (e.g., with a preamble) transmitted by passive network device 804. At 824, network entity 802 uses a timing offset 828 configured at passive network device 804, and the time for transmitting WUS 814 (e.g., T tx_WUS ) and the time of receiving (e.g., including the preamble) the first backscattered signal 818 (e.g., T rx_preamble TA 822 is calculated using the following equation: TA 822 represents the timing compensation required for uplink synchronization. The total timing error offset 831 (e.g., timing error offset 830 + propagation delay of WUS 814 + propagation delay of the first backscattered signal 818) is calculated according to the following equation:

[0173] In addition to calculating TA 822 (e.g., the required timing compensation for uplink synchronization), network entity 802 can also determine the frequency compensation 827 required for uplink synchronization at 824. The calculation of frequency compensation 827 can be similar to that described above. Figure 6 Frequency compensation 627 and Figure 7 The calculation of frequency compensation 727 in the middle.

[0174] In some respects, TA 822 and / or frequency compensation 827 are used to control the uplink transmission timing and / or frequency of subsequent uplink communication sent by passive network device 804 to network entity 802, respectively. In other words, passive network device 804 can use TA 822 and / or frequency compensation 827 to synchronize with network entity 802. Alternatively, network entity 802 can use TA 822 and / or frequency compensation 827 when receiving subsequent uplink communication from passive network device 804 and / or when transmitting carrier 820. In other words, network entity 802 can use TA 822 and / or frequency compensation 827 to synchronize with passive network device 804.

[0175] Figure 9 A process flow 900 is described for communication between network entity 902, passive network device 904, and RF entity 906 in a network. In some aspects, network entity 902 may be related to... Figure 1 and Figure 3 The BS102 described and depicted, regarding Figure 2 The decomposed BS described and illustrated, or about Figure 1 and Figure 3 The example depicted and described is UE 104. Similarly, passive network device 904 can be related to... Figure 1 and Figure 3 The UE 104 depicted and described or about Figure 1 and Figure 3 Examples of BS 102 depicted and described. In some respects, RF entity 906 may be about Figure 1 and Figure 3 The BS 102 described and depicted, regarding Figure 2 The decomposed BS described and illustrated, regarding Figure 1 and Figure 3Examples of UE 104, or IAB nodes, depicted and described herein. However, in other respects, passive network device 904 may be another type of passive wireless communication device, and network entity 902 and / or RF entity 906 may be another type of network entity or network node, such as those described herein.

[0176] As described above, Figure 9 Process flow 900 describes uplink synchronization between network entity 902 and passive network device 904 using only a single preamble (e.g., a second preamble in a configurable dual-sided preamble or a "preamble sent by the passive network device"). Passive network device 904 is triggered to send a second preamble based on the received WUS (e.g., WUS 914) instead of the first preamble (given that only one preamble is sent). Figure 9 In Chinese, this is referred to as a "preamble". However, compared to... Figure 8 different, Figure 9 The process flow 900 describes a scenario in which WUS 914 is sent by RF entity 906 instead of network entity 902.

[0177] For example, such as Figure 9 As shown, RF entity 906 sends WUS 914 and carrier 920 to passive network device 904, which can be similar to those described above for... Figure 8 The process flow 800 describes WUS 814 and carrier 820, although such signaling is transmitted by RF entity 906 rather than network entity 902. However, the first backscattered signal 918 received by network entity 902 can be similar to that in Figure 8 The first backscattered signal 818 is received by network entity 802. Furthermore, the variables used to calculate TA922 at 924 (e.g., timing offset 928 and total timing error offset 931) can be similarly represented in... Figure 8 The variable used to calculate TA 822 at position 824. Additionally, similar to... Figure 8 The frequency compensation of 827 is calculated at position 824, and the frequency compensation of 927 can be calculated at position 924. All aspects related to collision detection

[0178] exist Figures 6 to 9The scenario described above, which uses configurable dual-sided preambles to achieve uplink and / or downlink synchronization, assumes that the backscattered signal carrying the preamble from a passive network device does not conflict with the backscattered signal from another passive network device. While this may hold true in some cases, conflicts between backscattered signals can occur in others. A network entity receiving conflicting backscattered signals (e.g., each carrying a preamble configured for uplink synchronization) can detect the conflict by determining the presence of one or more correlation peaks in the correlation peak diagram. For example, a single correlation peak in the correlation peak diagram may indicate (1) no conflict has occurred, or (2) a conflict has occurred between backscattered signals carrying preambles for different passive network devices that have the same RTT calculated for them. Furthermore, two or more correlation peaks in the correlation peak diagram (e.g., for the backscattered link frequency) may indicate a conflict has occurred between backscattered signals carrying preambles for different passive network devices. Specifically, in the case where multiple (e.g., two or more) preambles from different devices are transmitted, multiple (e.g., two or more) correlation peaks can be found in the correlation peak diagram. Figure 11 An example correlation plot 1100 illustrating preamble / backscatter signal conflict is depicted. The x-axis of correlation plot 1100 represents the sample index, while the y-axis represents the correlation peak. (See diagram below.) Figure 11 As shown, there are two relevant peaks, 1102 and 1104, indicating that a conflict has occurred.

[0179] When a network entity detects a collision at a backscatter link frequency, the network entity may send an indication to two or more passive network devices that (1) synchronization of uplink communication between the network entity and a particular passive network device has failed due to a collision between a preamble sent by the passive network device and at least one other preamble sent by at least one other passive network device, and (2) the uplink synchronization process needs to be restarted (e.g., a new preamble needs to be sent by the particular passive network device). The network entity may also send an indication to each of the two or more passive network devices of the minimum TA to be used when sending subsequent preambles. The minimum TA may be: in min(RTT) This represents the minimum RTT among all RTTs calculated for passive network devices in response to a collision. min( )This can be equal to the time interval between the time when the first preamble is received last in time (e.g., in the case of multiple first preambles transmitted by multiple passive network devices) and the time when the second preamble is received first in time (e.g., in the case of multiple second preambles transmitted by multiple passive network devices). In some other cases, the minimum TA is calculated as... in this case, min( ) It can be equal to the time interval between the time of transmitting WUS and the time of receiving the first preamble in time (e.g., in the case where multiple preambles are transmitted by multiple passive network devices in a scenario where only one of the two configurable preambles is enabled).

[0180] Compensating with the minimum possible TA, each passive network device commanded to restart the synchronization process can begin the synchronization process (e.g., initiate a random access channel (RACH)) using a highly orthogonal sequence (such as carrier sense-based (CS) access / stockpiling).

[0181] In some cases, backscatter link frequencies are mapped one-to-one to passive network device preambles. Network entities can use this mapping to determine which passive network devices sent the preamble involved in the collision, allowing them to be notified that these passive network devices need to restart their uplink synchronization process. Example Operation

[0182] Figure 12 It shows a device (such as) Figure 5A Passive network devices 604 Figure 1 and Figure 3 UE 104 Figure 1 and Figure 3 BS 102 or about Figure 2 The method 1200 for wireless communication using the decomposed base station under discussion.

[0183] Method 1200 begins at step 1205: receiving a first preamble in one or more first symbols.

[0184] Then method 1200 proceeds to step 1210: sending a first backscatter signal to the network entity based on the first preamble.

[0185] Then method 1200 proceeds to step 1215: transmitting a carrier-based second backscatter signal to the network entity in one or more second symbols, the second backscatter signal including a second preamble, the second backscatter signal being transmitted in response to receiving a first preamble. In some aspects, the one or more second symbols are time-offset relative to one or more first symbols based on a timing offset configured at the device and a timing error offset of the device, and the second preamble is configured for synchronization of uplink communication between the device and the network entity.

[0186] In some aspects, method 1200 further includes randomly selecting a second preamble from a set of available preambles stored in one or more memories of the device in response to receiving the first preamble.

[0187] In some respects, before receiving the first preamble, method 1200 also includes receiving a WUS while in a sleep state, the WUS indicating that the device is awakened from the sleep state and monitoring the first preamble.

[0188] In some respects, method 1200 also includes receiving WUS and a first preamble from a network entity or RF entity.

[0189] In some respects, the WUS includes a group index, and method 1200 also includes waking from a sleep state based on the group index in response to receiving the WUS and monitoring the first preamble.

[0190] In some respects, the device is pre-configured to monitor the preamble after receiving a WUS with a group index.

[0191] In some respects, method 1200 also includes receiving a RA-RNTI assigned to the device, the RA-RNTI being associated with a group index.

[0192] In some respects, method 1200 also includes receiving multiple WUS, including the WUS, during one or more WUS monitoring intervals.

[0193] In some aspects, method 1200 also includes determining one of a plurality of WUS to respond by means of a random process. In some aspects, the one WUS includes the WUS.

[0194] In some respects, method 1200 also includes waking up based on the received WUS and monitoring the first preamble.

[0195] In some respects, the WUS is a device-specific WUS and instructs the device to wake up and monitor the first preamble, and method 1200 further includes waking up and monitoring the first preamble based on receiving the device-specific WUS.

[0196] In some respects, WUS indicates that the transmission of the first preamble is enabled.

[0197] In some respects, WUS includes an indication of the symbol index of the starting symbol in one or more first symbols.

[0198] In some respects, the timing offset is limited within WUS.

[0199] In some respects, the timing offset is based on the position of one or more first symbols in the time slot.

[0200] In some respects, one or more first symbols include the symbol of the time slot, but do not include the last symbol of the time slot.

[0201] In some respects, method 1200 also includes sending at least one of the following to the network entity: the device's timing resolution capability or the device's frequency shift capability.

[0202] In some aspects, method 1200 further includes receiving from a network entity an indication that the device will synchronize uplink communication between the device and the network entity based on either the device's timing resolution capability or its frequency shift capability, after at least one of the transmitting device's timing resolution capability or its frequency shift capability.

[0203] In some respects, method 1200 also includes receiving a TA value from a network entity for uplink communication.

[0204] In some respects, the TA value is at least partially based on the timing error offset of the device.

[0205] In some respects, method 1200 also includes receiving frequency compensation values ​​from a network entity for use in synchronizing uplink communication.

[0206] In some respects, method 1200 further includes receiving from a network entity an indication that the network entity will synchronize uplink communication between the device and the network entity after at least one of the timing resolution capability or the frequency shift capability of the transmitting device.

[0207] In some respects, the carrier is intended for use with multiple passive network devices, including the device, and method 1200 also includes receiving an indication from a network entity regarding the device synchronizing uplink communication between the device and the network entity.

[0208] In some respects, the carrier is a dedicated signal intended only for use with the device, and method 1200 also includes receiving an indication from the network entity that the network entity will synchronize uplink communication between the device and the network entity.

[0209] In some respects, the first preamble is received using a first frequency, the first backscattered signal is transmitted using a second frequency, and the second preamble is transmitted using a second frequency.

[0210] In some aspects, method 1200 further includes randomly selecting a frequency shift from a pre-configured set of frequency shifts at the device. In some aspects, the second frequency differs from the first frequency by the frequency shift selected by the device.

[0211] In some aspects, method 1200 further includes determining the frequency shift based on the RA-RNTI assigned to the device. In some aspects, the second frequency differs from the first frequency by this frequency shift.

[0212] In some respects, the device is configured using a frequency shift, and the second frequency differs from the first frequency by that frequency shift.

[0213] In some respects, method 1200 also includes receiving from a network entity an indication that synchronization of uplink communication between the device and the network entity has failed due to a conflict between a second preamble and at least one other preamble.

[0214] In some respects, method 1200 also includes receiving from a network entity a message indicating the TA value to be used when sending another preamble.

[0215] In some respects, the second preamble includes a random access channel preamble, a simplified random access channel preamble, or another type of preamble.

[0216] In some respects, the device receives the first preamble after a periodic timer, which is started after the initial access between the device and the network entity, expires.

[0217] In some respects, the device receives the first preamble after a shift in the receive or transmit frequency used for uplink communication with network entities.

[0218] In some respects, method 1200 or any aspect thereof may be made possible by means of a device (such as...) Figure 18 The communication device 1800 is used to perform the method, which includes various components capable of operating, configured, or adapted to perform the method 1200. The communication device 1800 is described in further detail below.

[0219] It should be noted that Figure 12 This is merely one example of a method, and other methods that include fewer, additional, or alternative steps may also be consistent with this disclosure.

[0220] Figure 13 It shows a device (such as) Figure 1 and Figure 3 BS 102, Regarding Figure 2The decomposed base station discussed Figure 1 and Figure 3 Method 1300 for wireless communication of UE 104.

[0221] Method 1300 begins at step 1305: a first preamble is sent to at least one passive network device in one or more first symbols.

[0222] Then method 1300 proceeds to step 1310: receiving a first backscatter signal for the first preamble from at least one passive network device.

[0223] Then method 1300 proceeds to step 1315: calculate the RTT of the first preamble.

[0224] Then method 1300 proceeds to step 1320: receiving a second backscattered signal from at least one passive network device in one or more second symbols, the second backscattered signal including a second preamble received in response to the transmission of a first preamble. In some aspects, the one or more second symbols are time-offset relative to one or more first symbols, and the second preamble is configured for synchronization of uplink communication between the device and at least one passive network device.

[0225] Then method 1300 proceeds to step 1325: determining the timing error offset of at least one passive network device based on the time offset between one or more first symbols and one or more second symbols, the RTT of the first preamble, and the timing offset configured at the device.

[0226] Then method 1300 proceeds to step 1330: calculate the TA value for uplink communication between the device and at least one passive network device based on the RTT of the first preamble and the timing error offset of at least one passive network device.

[0227] In some respects, method 1300 also includes using RTT to decode the second preamble.

[0228] In some respects, method 1300 also includes sending WUS before sending the first preamble.

[0229] In some respects, WUS includes group indexes.

[0230] In some respects, method 1300 also includes sending multiple WUS, including the WUS.

[0231] In some respects, WUS includes WUS dedicated to a single passive network device.

[0232] In some respects, WUS indicates that the transmission of the first preamble by the device is enabled.

[0233] In some respects, WUS includes an indication of the symbol index of the starting symbol in one or more first symbols.

[0234] In some respects, the timing offset is limited within WUS.

[0235] In some respects, the timing offset is based on the position of one or more first symbols in the time slot.

[0236] In some respects, method 1300 also includes calculating RA-RNTI based on the second preamble associated with WUS and the frequency of the second preamble.

[0237] In some respects, method 1300 also includes scrambling a message indicating a TA value to be used for uplink communication using RA-RNTI.

[0238] In some respects, method 1300 also includes sending a TA value to at least one passive network device for uplink communication.

[0239] In some respects, one or more first symbols include the symbols of a time slot other than the last symbol of that time slot.

[0240] In some aspects, method 1300 further includes receiving at least one of the following from at least one passive network device: timing resolution capability of at least one passive network device or frequency shift capability of at least one passive network device.

[0241] In some aspects, method 1300 further includes sending an indication to at least one passive network device, after receiving at least one of the timing resolution capability or the frequency shift capability of at least one passive network device, that the at least one passive network device will synchronize uplink communication between the means and at least one passive network device based on the timing resolution capability or the frequency shift capability of at least one passive network device.

[0242] In some respects, method 1300 also includes sending a TA value to at least one passive network device for synchronizing uplink communication.

[0243] In some respects, method 1300 also includes sending frequency compensation values ​​to at least one passive network device for synchronizing uplink communication.

[0244] In some aspects, method 1300 further includes sending an indication to at least one passive network device, after receiving at least one of the timing resolution capability or the frequency shift capability of at least one passive network device, that the device will synchronize uplink communication between the device and at least one passive network device based on the timing resolution capability or the frequency shift capability of at least one passive network device.

[0245] In some respects, method 1300 also includes transmitting one or more signals to at least one passive network device using a frequency based on the frequency shift.

[0246] In some respects, method 1300 also includes receiving uplink communication from at least one passive network device using a frequency based on frequency shift.

[0247] In some respects, the first preamble is transmitted using a first frequency, the first backscatter signal is received from at least one passive network device using a second frequency, and the second backscatter signal is received using a second frequency.

[0248] In some aspects, method 1300 also includes configuring at least one passive network device using a frequency shift. In some aspects, the second frequency differs from the first frequency by the frequency shift.

[0249] In some respects, method 1300 also includes sending a third preamble to at least one passive network device in one or more third symbols.

[0250] In some respects, method 1300 also includes receiving a third backscatter signal for a third preamble from at least one passive network device.

[0251] In some respects, method 1300 also includes calculating the second RTT of the third preamble.

[0252] In some aspects, method 1300 further includes receiving a fourth backscattered signal including the fourth preamble from at least one passive network device in one or more fourth symbols in response to transmitting a third preamble. In some aspects, the one or more fourth symbols are time-offset relative to one or more third symbols, and the fourth preamble is configured for synchronization of uplink communication between the device and at least one passive network device.

[0253] In some respects, method 1300 also includes determining that the fourth preamble conflicts with at least one other preamble sent by at least one other passive network device.

[0254] In some respects, method 1300 further includes sending an indication to at least one passive network device regarding a synchronization failure in uplink communication between the device and at least one passive network device based on determining that the fourth preamble conflicts with at least one other preamble.

[0255] In some respects, method 1300 also includes calculating a second TA value based on the minimum RTT and minimum timing error offset associated with at least one passive network device or at least one other passive network device.

[0256] In some respects, method 1300 also includes sending a second TA value to at least one passive network device for use when sending another preamble.

[0257] In some respects, determining that the fourth preamble conflicts with at least one other preamble involves detecting multiple related peaks.

[0258] In some respects, the second preamble includes a random access channel preamble, a simplified random access channel preamble, or another type of preamble.

[0259] In some respects, method 1300 further includes sending a first preamble after a periodic timer started after the initial access between the device and at least one passive network device expires.

[0260] In some respects, prior to sending the first preamble, method 1300 further includes determining that uplink communication from at least one passive network device deviates from expected uplink communication in time or frequency by at least a threshold amount.

[0261] In some respects, before sending the first preamble, method 1300 also includes detecting frequency shifts in uplink communication from at least one passive network device.

[0262] In some respects, method 1300 or any aspect thereof may be made by means of a device (such as...) Figure 19 The communication device 1900 is used to perform the method, which includes various components capable of operating, configured, or adapted to perform the method 1300. The communication device 1900 is described in further detail below.

[0263] It should be noted that Figure 13 This is merely one example of a method, and other methods that include fewer, additional, or alternative steps may also be consistent with this disclosure.

[0264] Figure 14 It shows a device (such as) Figure 1 and Figure 3 BS 102, Regarding Figure 2 The decomposed base station discussed or Figure 1 and Figure 3Method 1400 for wireless communication of UE 104.

[0265] Method 1400 begins at step 1405: receiving a backscattered signal from at least one passive network device in one or more first symbols, the backscattered signal including a first preamble sent by an RF entity to at least one passive network device.

[0266] Then method 1400 proceeds to step 1410: determine the RTT of the first preamble.

[0267] Then method 1400 proceeds to step 1415: receiving a second backscattered signal, including a second preamble, from at least one passive network device in one or more second symbols. In some respects, the one or more second symbols are time-offset relative to one or more first symbols, and the second preamble is configured for synchronization of uplink communication between the device and at least one passive network device.

[0268] Then method 1400 proceeds to step 1420: determining the timing error offset of at least one passive network device based on the time offset between one or more first symbols and one or more second symbols, the RTT of the first preamble, and the timing offset configured at the device.

[0269] Then method 1400 proceeds to step 1425: calculate the TA value for uplink communication between the device and at least one passive network device based on the RTT of the first preamble and the timing error offset of at least one passive network device.

[0270] In some respects, method 1400 also includes using RTT to decode the second preamble.

[0271] In some aspects, method 1400 further includes receiving at least one of the following from at least one passive network device: timing resolution capability of at least one passive network device or frequency shift capability of at least one passive network device.

[0272] In some aspects, method 1400 further includes sending an indication to at least one passive network device, after receiving at least one of the timing resolution capability or the frequency shift capability of at least one passive network device, that the at least one passive network device will synchronize uplink communication between the device and the at least one passive network device based on the timing resolution capability or the frequency shift capability of the at least one passive network device.

[0273] In some respects, method 1400 also includes sending a TA value to at least one passive network device for synchronizing uplink communication.

[0274] In some respects, method 1400 also includes sending frequency compensation values ​​to at least one passive network device for synchronizing uplink communication.

[0275] In some aspects, method 1400 further includes sending an indication to at least one passive network device, after receiving at least one of the timing resolution capability or the frequency shift capability of at least one passive network device, that the device will synchronize uplink communication between the device and at least one passive network device based on the timing resolution capability or the frequency shift capability of at least one passive network device.

[0276] In some respects, method 1400 also includes transmitting one or more signals to at least one passive network device using a frequency based on the frequency shift.

[0277] In some respects, method 1400 also includes receiving uplink communication from at least one passive network device using a frequency based on frequency shift.

[0278] In some aspects, method 1400 further includes receiving a third backscattered signal from at least one passive network device in one or more third symbols, the third backscattered signal including a third preamble sent by an RF entity to at least one passive network device.

[0279] In some aspects, method 1400 further includes calculating a second RTT of a third preamble, receiving a fourth backscattered signal including the fourth preamble from at least one passive network device in one or more fourth symbols. In some aspects, the one or more fourth symbols are time-offset relative to one or more third symbols, and the fourth preamble is configured for synchronization of uplink communication between the device and at least one passive network device.

[0280] In some respects, method 1400 also includes determining that the fourth preamble conflicts with at least one other preamble sent by at least one other passive network device.

[0281] In some aspects, method 1400 also includes sending an indication to at least one passive network device regarding a synchronization failure in uplink communication between the device and at least one passive network device based on determining that the fourth preamble conflicts with at least one other preamble.

[0282] In some respects, determining that the fourth preamble conflicts with at least one other preamble involves detecting multiple related peaks.

[0283] In some respects, method 1400 also includes calculating a second TA value based on the minimum RTT and minimum timing error offset associated with at least one passive network device or at least one other passive network device.

[0284] In some respects, method 1400 also includes sending a second TA value to at least one passive network device for use when sending another preamble.

[0285] In some respects, the second preamble includes a random access channel preamble, a simplified random access channel preamble, or another type of preamble.

[0286] In some respects, method 1400 or any aspect thereof may be made by means of a device (such as...) Figure 19 The communication device 1900 is used to perform the method, which includes various components capable of operating, configured, or adapted to perform the method 1400. The communication device 1900 is described in further detail below.

[0287] It should be noted that Figure 14 This is merely one example of a method, and other methods that include fewer, additional, or alternative steps may also be consistent with this disclosure.

[0288] Figure 15 It shows a device (such as) Figure 5A Passive network devices 604 Figure 1 and Figure 3 UE 104 Figure 1 and Figure 3 BS 102 or about Figure 2 The method for wireless communication using the decomposed base station discussed in the article 1500.

[0289] Method 1500 begins at step 1505: receiving WUS in one or more first symbols while in a sleep state.

[0290] Then method 1500 proceeds to step 1510: in response to receiving WUS, transition from sleep state to wake state.

[0291] Then method 1500 proceeds to step 1515: transmitting a carrier-based backscattered signal to the network entity in one or more second symbols, the backscattered signal including a preamble transmitted in response to receiving WUS. In some aspects, the one or more second symbols are time-offset relative to one or more first symbols based on a timing offset configured at the device and a timing error offset of the device, and the preamble is configured for synchronization of uplink communication between the device and the network entity.

[0292] In some respects, method 1500 also includes receiving WUS from a network entity or RF entity.

[0293] In some respects, method 1500 also includes randomly selecting a preamble from a list of available preambles stored in one or more memories of the device in response to receiving WUS.

[0294] In some respects, WUS includes a group index, and method 1500 also includes transitioning from a sleep state to a wakeful state based on the group index included in WUS.

[0295] In some respects, the device is pre-configured to monitor preambles from network entities after receiving a WUS with a group index.

[0296] In some respects, method 1500 also includes receiving a RA-RNTI assigned to the device, which is associated with a group index.

[0297] In some respects, method 1500 also includes receiving multiple WUS, including the WUS, during one or more WUS monitoring intervals.

[0298] In some aspects, method 1500 also includes determining one of a plurality of WUS to respond by means of a random process. In some aspects, the one WUS includes the WUS.

[0299] In some respects, Method 1500 also includes the transition from a sleep state to a wakeful state.

[0300] In some respects, WUS is a WUS specifically designed for devices.

[0301] In some respects, WUS indicates that the transmission of another preamble by a network entity is disabled.

[0302] In some respects, WUS includes an indication of the symbol index of the starting symbol in one or more first symbols.

[0303] In some respects, timing offsets are limited in WUS.

[0304] In some respects, the timing offset is based on the position of one or more first symbols in the time slot.

[0305] In some respects, one or more first symbols include the symbol of the time slot, but do not include the last symbol of the time slot.

[0306] In some respects, method 1500 also includes sending at least one of the following to the network entity: the device's timing resolution capability or the device's frequency shift capability.

[0307] In some aspects, method 1500 further includes receiving from a network entity an indication that the device will synchronize uplink communication between the device and the network entity based on either the device's timing resolution capability or its frequency shift capability, after at least one of the transmitting device's timing resolution capability or its frequency shift capability.

[0308] In some respects, method 1500 also includes receiving a TA value from a network entity to be used for synchronizing uplink communication.

[0309] In some respects, the TA value is at least partially based on the timing error offset of the device.

[0310] In some respects, method 1500 also includes receiving frequency compensation values ​​from a network entity for use in synchronizing uplink communication.

[0311] In some aspects, method 1500 further includes receiving from the network entity an indication that the network entity will synchronize uplink communication between the device and the network entity after at least one of the timing resolution capability or the frequency shift capability of the transmitting device.

[0312] In some respects, a carrier wave is a dedicated signal intended solely for use with a device.

[0313] In some respects, the carrier is intended for use with multiple passive network devices, including the device, and method 1500 also includes receiving an indication from a network entity that the device will synchronize uplink communication between the device and the network entity.

[0314] In some respects, WUS is received using a first frequency, and the backscattered signal is transmitted using a second frequency.

[0315] In some aspects, method 1500 further includes randomly selecting a frequency shift from a set of frequency shifts pre-configured at the device. In some aspects, the second frequency differs from the first frequency by the frequency shift selected by the device.

[0316] In some respects, the device is configured using a frequency shift, and the second frequency differs from the first frequency by that frequency shift.

[0317] In some aspects, method 1500 further includes determining the frequency shift based on the RA-RNTI assigned to the device. In some aspects, the second frequency differs from the first frequency by this frequency shift.

[0318] In some respects, method 1500 also includes receiving from a network entity an indication that synchronization of uplink communication between the device and the network entity has failed due to a conflict between a preamble and at least one other preamble.

[0319] In some respects, method 1500 also includes receiving from a network entity a message indicating the TA value to be used when sending another preamble.

[0320] In some respects, preambles include random access channel preambles, simplified random access channel preambles, or another type of preamble.

[0321] In some respects, the device receives the WUS after a periodic timer, which is started after the initial access between the device and the network entity, expires.

[0322] In some respects, the device receives WUS after a shift in the receive or transmit frequency used for uplink communication with network entities.

[0323] In some respects, method 1500 or any aspect thereof may be made by means of a device (such as...) Figure 5A Passive network devices 506 or Figure 18 The communication device 1800 is used to perform the method, which includes various components capable of operating, configured, or adapted to perform the method 1500. The communication device 1800 is described in further detail below.

[0324] It should be noted that Figure 15 This is merely one example of a method, and other methods that include fewer, additional, or alternative steps may also be consistent with this disclosure.

[0325] Figure 16 It shows a device (such as) Figure 1 and Figure 3 BS 102, Regarding Figure 2 The decomposed base station discussed or Figure 1 and Figure 3 Method 1600 for wireless communication of UE 104.

[0326] Method 1600 begins at step 1605: while in a sleep state, WUS is sent to at least one passive network device in one or more first symbols.

[0327] Method 1600 then proceeds to step 1610: receiving a backscattered signal from at least one passive network device in one or more second symbols, the backscattered signal including a preamble received in response to the transmission of WUS. In some respects, the one or more second symbols are time-offset relative to one or more first symbols, and the preamble is configured for synchronization of uplink communication between the device and at least one passive network device.

[0328] Then method 1600 proceeds to step 1615: determining the timing error offset of at least one passive network device based on the time offset between one or more first symbols and one or more second symbols and the timing offset configured at at least one passive network device.

[0329] Then method 1600 proceeds to step 1620: calculate the TA value for uplink communication based on the timing error offset.

[0330] In some respects, WUS includes group indexes.

[0331] In some respects, method 1600 also includes sending multiple WUS, including the WUS.

[0332] In some respects, WUS includes WUS dedicated to a single passive network device.

[0333] In some respects, WUS indicates that the transmission of another preamble by the device is disabled.

[0334] In some respects, WUS includes an indication of the symbol index of the starting symbol in one or more first symbols.

[0335] In some respects, the timing offset is limited within WUS.

[0336] In some respects, the timing offset is based on the position of one or more first symbols in the time slot.

[0337] In some respects, one or more first symbols include the symbols of a time slot other than the last symbol of that time slot.

[0338] In some respects, method 1600 also includes calculating RA-RNTI based on the preamble associated with WUS and the frequency of the preamble.

[0339] In some respects, method 1600 also includes scrambling a message indicating a TA value to be used for uplink communication using RA-RNTI.

[0340] In some respects, method 1600 also includes sending a TA value to at least one passive network device for uplink communication.

[0341] In some aspects, method 1600 further includes receiving at least one of the following from at least one passive network device: timing resolution capability of at least one passive network device or frequency shift capability of at least one passive network device.

[0342] In some aspects, method 1600 further includes sending an indication to at least one passive network device, after receiving at least one of the timing resolution capability or the frequency shift capability of at least one passive network device, that the at least one passive network device will synchronize uplink communication between the device and the at least one passive network device based on the timing resolution capability or the frequency shift capability of the at least one passive network device.

[0343] In some respects, method 1600 also includes sending a TA value to at least one passive network device for synchronizing uplink communication.

[0344] In some respects, method 1600 also includes sending frequency compensation values ​​to at least one passive network device for synchronizing uplink communication.

[0345] In some aspects, method 1600 further includes sending an indication to at least one passive network device, after receiving at least one of the timing resolution capability or the frequency shift capability of at least one passive network device, that the device will synchronize uplink communication between the device and at least one passive network device based on the timing resolution capability or the frequency shift capability of at least one passive network device.

[0346] In some respects, method 1600 also includes transmitting one or more signals to at least one passive network device using a frequency based on the frequency shift.

[0347] In some respects, method 1600 also includes receiving uplink communication from at least one passive network device using a frequency based on frequency shift.

[0348] In some respects, WUS is transmitted using a first frequency, and the backscattered signal is received using a second frequency.

[0349] In some aspects, method 1600 also includes configuring at least one passive network device using a frequency shift. In some aspects, the second frequency differs from the first frequency by the frequency shift.

[0350] In some aspects, method 1600 also includes configuring at least one passive network device using frequency shift. In some aspects, a frequency based on the frequency shift is used to receive the backscattered signal.

[0351] In some respects, method 1600 also includes sending a second WUS to at least one passive network device in one or more third symbols.

[0352] In some aspects, method 1600 further includes receiving a second backscattered signal from at least one passive network device in one or more fourth symbols, the second backscattered signal including a second preamble received in response to the transmission of a second WUS. In some aspects, the one or more fourth symbols are time-offset relative to one or more third symbols, and the second preamble is configured for synchronization of uplink communication between the device and at least one passive network device.

[0353] In some respects, method 1600 also includes determining that the second preamble conflicts with at least one other preamble sent by at least one other passive network device.

[0354] In some aspects, method 1600 further includes sending an indication to at least one passive network device regarding a synchronization failure in uplink communication between the device and at least one passive network device based on determining that the second preamble conflicts with at least one other preamble sent by at least one other passive network device.

[0355] In some respects, method 1600 also includes calculating a second TA value based on a minimum timing error offset associated with at least one passive network device or at least one other passive network device.

[0356] In some respects, method 1600 also includes sending a second TA value to be used when sending the third preamble to at least one passive network device.

[0357] In some respects, determining that the second preamble conflicts with at least one other preamble sent by at least one other passive network device involves detecting multiple related peaks.

[0358] In some respects, preambles include random access channel preambles, simplified random access channel preambles, or another type of preamble.

[0359] In some respects, method 1600 also includes sending WUS after the expiration of a periodic timer started after the initial access between the device and at least one passive network device.

[0360] In some respects, prior to sending the WUS, method 1600 further includes determining that uplink communication from at least one passive network device deviates from expected uplink communication in time or frequency by at least a threshold amount.

[0361] In some respects, method 1600 also includes detecting frequency shifts in uplink communication from at least one passive network device before sending WUS.

[0362] In some respects, method 1600 or any aspect thereof may be made by means of a device (such as...) Figure 19 The communication device 1900 performs the operation, and the device includes various components capable of operating, configured, or adapted to perform the method 1600. The communication device 1900 is described in further detail below.

[0363] It should be noted that Figure 16 This is merely one example of a method, and other methods that include fewer, additional, or alternative steps may also be consistent with this disclosure.

[0364] Figure 17 It shows a device (such as) Figure 1 and Figure 3 BS 102, Regarding Figure 2 The decomposed base station discussed or Figure 1 and Figure 3 Method 1700 for wireless communication of UE 104.

[0365] Method 1700 begins at step 1705: Determine that the RF entity sent WUS to at least one passive network device in one or more first symbols.

[0366] Method 1700 then proceeds to step 1710: receiving a backscattered signal from at least one passive network device in one or more second symbols, the backscattered signal including a preamble received in response to a transmission to the WUS by an RF entity. In some respects, the one or more second symbols are time-offset relative to one or more first symbols, and the preamble is configured for synchronization of uplink communication between the device and at least one passive network device.

[0367] Then method 1700 proceeds to step 1715: determining the timing error offset of at least one passive network device based on the time offset between one or more first symbols and one or more second symbols and the timing offset configured at at least one passive network device.

[0368] Then method 1700 proceeds to step 1720: calculate the TA value for uplink communication based on the timing error offset.

[0369] In some respects, method 1700 also includes calculating RA-RNTI based on the preamble associated with WUS and the frequency of the preamble.

[0370] In some respects, method 1700 also includes scrambling a message indicating a TA value to be used for uplink communication using RA-RNTI.

[0371] In some respects, method 1700 also includes sending a TA value to at least one passive network device for uplink communication.

[0372] In some aspects, method 1700 further includes receiving at least one of the following from at least one passive network device: timing resolution capability of at least one passive network device or frequency shift capability of at least one passive network device.

[0373] In some aspects, method 1700 further includes sending an indication to at least one passive network device, after receiving at least one of the timing resolution capability or the frequency shift capability of at least one passive network device, that the at least one passive network device will synchronize uplink communication between the means and at least one passive network device based on the timing resolution capability or the frequency shift capability of at least one passive network device.

[0374] In some respects, method 1700 also includes sending a TA value to at least one passive network device for synchronizing uplink communication.

[0375] In some respects, method 1700 also includes sending frequency compensation values ​​to at least one passive network device for synchronizing uplink communication.

[0376] In some aspects, method 1700 further includes sending an indication to at least one passive network device, after receiving at least one of the timing resolution capability or the frequency shift capability of at least one passive network device, that the device will synchronize uplink communication between the device and at least one passive network device based on the timing resolution capability or the frequency shift capability of at least one passive network device.

[0377] In some respects, method 1700 also includes transmitting one or more signals to at least one passive network device using a frequency based on the frequency shift.

[0378] In some respects, method 1700 also includes receiving uplink communication from at least one passive network device using a frequency based on frequency shift.

[0379] In some respects, method 1700 also includes determining that the RF entity sent a second WUS to at least one passive network device in one or more third symbols.

[0380] In some aspects, method 1700 further includes receiving a second backscattered signal from at least one passive network device in one or more fourth symbols, the second backscattered signal including a second preamble received in response to the transmission of a second WUS. In some aspects, the one or more fourth symbols are time-offset relative to one or more third symbols, and the second preamble is configured for synchronization of uplink communication between the device and at least one passive network device.

[0381] In some respects, method 1700 also includes determining that the second preamble conflicts with at least one other preamble sent by at least one other passive network device.

[0382] In some aspects, method 1700 further includes sending an indication to at least one passive network device regarding a synchronization failure in uplink communication between the device and at least one passive network device based on determining that the second preamble conflicts with at least one other preamble sent by at least one other passive network device.

[0383] In some respects, method 1700 also includes calculating a second TA value based on a minimum timing error offset associated with at least one passive network device or at least one other passive network device.

[0384] In some respects, method 1700 also includes sending a second TA value to be used when sending a third preamble to at least one passive network device.

[0385] In some respects, determining that the second preamble conflicts with at least one other preamble sent by at least one other passive network device involves detecting multiple related peaks.

[0386] In some respects, preambles include random access channel preambles, simplified random access channel preambles, or another type of preamble.

[0387] In some respects, method 1700 or any aspect thereof may be made by means of a device (such as...) Figure 5A Passive network devices 506 or Figure 19 The communication device 1900 is used to perform the method, which includes various components capable of operating, configured, or adapted to perform the method 1700. The communication device 1900 is described in further detail below.

[0388] It should be noted that Figure 17 This is merely one example of a method, and other methods that include fewer, additional, or alternative steps may also be consistent with this disclosure. Example communication device

[0389] Figure 18 Various aspects of the example communication device 1800 are described. In some aspects, the communication device 1800 is user equipment, such as those mentioned above. Figure 1 and Figure 3 The UE 104 is described. In some respects, the communication device 1800 is a network entity, such as... Figure 1 and Figure 3 BS 102 or as about Figure 2 The decomposed base station under discussion.

[0390] Communication device 1800 includes a processing system 1805 coupled to a transceiver 1885 (e.g., a transmitter and / or receiver) and / or a network interface 1895. The transceiver 1885 is configured to transmit and receive signals for communication device 1800 via antenna 1890, such as various signals as described herein. The network interface 1895 is configured to transmit and receive signals for communication device 1800 via a communication link (such as those described herein). Figure 2 The described backhaul link, midhaul link, and / or fronthaul link receive and transmit signals for communication device 1800. Processing system 1805 can be configured to perform processing functions of communication device 1800, including processing signals received by communication device 1800 and / or to be transmitted by the communication device.

[0391] The processing system 1805 includes one or more processors 1810. In various aspects, the one or more processors 1810 may represent one or more of the following: receive processor 338, receive processor 358, transmit processor 320, transmit processor 364, TX MIMO processor 330, TX MIMO processor 366, controller / processor 340, and / or controller / processor 380, as per [reference to...]. Figure 3 As described. One or more processors 1810 are coupled to a computer-readable medium / memory 1845 via a bus 1880. In some aspects, the computer-readable medium / memory 1845 is configured to store instructions (e.g., computer-executable code) that, when executed by the one or more processors 1810, enable the one or more processors 1810 to execute and cause the one or more processors to perform actions related to... Figure 12 The described method 1200 or any aspect thereof, including regarding Figure 12 Any additional steps or sub-steps described; and regarding Figure 15 The described method 1500 or any aspect thereof, including regarding Figure 15 Any additional steps or sub-steps described. Note that references to processors performing the functions of communication device 1800 may include one or more processors, such as performing the functions of communication device 1800 in a distributed manner.

[0392] In the depicted example, computer-readable medium / memory 1845 stores code 1850 for receiving, code 1855 for transmitting, code 1860 for random selection, code 1865 for determining, code 1870 for waking up, and code 1875 for transition. Processing of codes 1850 to 1875 enables communication device 1800 to execute and allows the communication device to perform actions related to... Figure 12 The described method 1200 or any aspect thereof; and regarding Figure 15 The method described 1500 or any aspect thereof.

[0393] One or more processors 1810 include circuitry configured to implement (e.g., execute) code stored in a computer-readable medium / memory 1845. This circuitry includes circuitry 1815 for receiving, circuitry 1820 for transmitting, circuitry 1825 for random selection, circuitry 1830 for determining, circuitry 1835 for waking up, and circuitry 1840 for transitioning. Processing using circuitry 1815 to 1840 enables communication device 1800 to perform and allow the communication device to perform actions related to... Figure 12 The described method 1200 or any aspect thereof; and regarding Figure 15The method described 1500 or any aspect thereof.

[0394] More generally, components used for communication, sending, transmitting, or outputting in order to perform transmission may include: Figure 3 The transceiver 332, antenna 334, transmit processor 320, TX MIMO processor 330 and / or controller / processor 340 of the BS 102 illustrated herein; Figure 3 The transceiver 354, antenna 352, transmit processor 364, TX MIMO processor 366 and / or controller / processor 380 of the UE 104 illustrated herein; Figure 18 The transceiver 1885 and / or antenna 1890 of the communication equipment 1800; and / or Figure 18 One or more processors 1810 of the communication device 1800. Components for communicating, receiving, or acquiring may include: Figure 3 The transceiver 332, antenna 334, receiver processor 338 and / or controller / processor 340 of the BS 102 illustrated herein; Figure 3 The transceiver 354, antenna 352, receiver processor 358 and / or controller / processor 380 of the UE 104 illustrated herein; Figure 18 The transceiver 1885 and / or antenna 1890 of the communication equipment 1800; and / or Figure 18 One or more processors 1804 of the communication device 1800 in the middle.

[0395] Figure 19 Various aspects of the example communication device 1900 are described. In some aspects, the communication device 1900 is a network entity, such as... Figure 1 and Figure 3 BS 102 or as about Figure 2 The decomposed base station under discussion.

[0396] Communication device 1900 includes a processing system 1902 coupled to a transceiver 1938 (e.g., a transmitter and / or receiver) and / or a network interface 1942. Transceiver 1938 is configured to transmit and receive signals for communication device 1900 via antenna 1940, such as various signals as described herein. Network interface 1942 is configured to transmit and receive signals for communication device 1900 via a communication link (such as those described herein). Figure 2 The described backhaul link, midhaul link, and / or fronthaul link receive and transmit signals for the communication device 1900. The processing system 1902 can be configured to perform the processing functions of the communication device 1900, including processing signals received by the communication device 1900 and / or to be transmitted by the communication device.

[0397] Processing system 1902 includes one or more processors 1904. In various aspects, one or more processors 1904 may represent one or more of a receive processor 338, a transmit processor 320, a TX MIMO processor 330, and / or a controller / processor 340, as per [reference to...]. Figure 3 As described. One or more processors 1904 are coupled to a computer-readable medium / memory 1920 via a bus 1936. In some aspects, the computer-readable medium / memory 1920 is configured to store instructions (e.g., computer-executable code) that, when executed by one or more processors 1904, enable one or more processors 1904 to execute and cause the one or more processors to perform actions regarding... Figure 13 The described method 1300 or any aspect thereof, including regarding Figure 13 Any additional steps or sub-steps described; regarding Figure 14 The described method 1400 or any aspect thereof, including regarding Figure 14 Any additional steps or sub-steps described; regarding Figure 16 The described method 1600 or any aspect thereof, including regarding Figure 16 Any additional steps or sub-steps described; and regarding Figure 17 The described method 1700 or any aspect thereof, including regarding Figure 17 Any additional steps or sub-steps described. Note that references to the processor of the communication device 1900 performing the function may include one or more processors of the communication device 1900, such as those performing the function in a distributed manner.

[0398] In the depicted example, computer-readable medium / memory 1920 stores code 1922 for transmitting, code 1924 for receiving, code 1926 for calculating, code 1928 for determining, code 1930 for decoding, code 1932 for scrambling, and code 1934 for configuring. Processing of codes 1922 to 1934 enables communication device 1900 to perform and allow the communication device to perform actions related to... Figure 13 The described method 1300 or any aspect thereof; regarding Figure 14 The described method 1400 or any aspect thereof; regarding Figure 16 The described method 1600 or any aspect thereof; and regarding Figure 17 The method described is 1700 or any aspect thereof.

[0399] One or more processors 1904 include circuitry configured to implement (e.g., execute) code stored in a computer-readable medium / memory 1920. This circuitry includes circuitry 1906 for transmitting, circuitry 1908 for receiving, circuitry 1910 for calculating, circuitry 1912 for determining, circuitry 1914 for decoding, circuitry 1916 for scrambling, and circuitry 1918 for configuring. Processing using circuitry 1906 to 1918 enables communication device 1900 to perform and allow the communication device to perform actions related to... Figure 13 The described method 1300 or any aspect thereof; regarding Figure 14 The described method 1400 or any aspect thereof; regarding Figure 16 The described method 1600 or any aspect thereof; and regarding Figure 17 The method described is 1700 or any aspect thereof.

[0400] More generally, components used for conveying, sending, transmitting, or outputting for transmission may include Figure 3 The transceiver 332, antenna 334, transmit processor 320, TX MIMO processor 330, and / or controller / processor 340 of the BS102 illustrated herein are also described. Figure 19 The communication equipment in 1900, transceivers in 1938 and / or antennas in 1940, and / or Figure 19 One or more processors 1904 of the communication device 1900. Components for transmitting, receiving, or obtaining may include... Figure 3 The transceiver 332, antenna 334, receiver processor 338, and / or controller / processor 340 of the BS 102 illustrated herein are shown in the diagram. Figure 19 The communication equipment in 1900, transceivers in 1938 and / or antennas in 1940, and / or Figure 19 One or more processors 1904 in the communication device 1900. Example Terms

[0401] Specific implementation examples are described in the following numbered clauses:

[0402] Clause 1: A method for wireless communication by a device, the method comprising: receiving a first preamble in one or more first symbols; transmitting a first backscatter signal to a network entity based on the first preamble; and transmitting a carrier-based second backscatter signal to the network entity in one or more second symbols, the second backscatter signal including a second preamble, the second backscatter signal being transmitted in response to receiving the first preamble, wherein: the one or more second symbols are time-offset relative to the one or more first symbols based on a timing offset configured at the device and a timing error offset of the device, and the second preamble is configured for synchronization of uplink communication between the device and the network entity.

[0403] Clause 2: The method according to Clause 1 further includes: in response to receiving the first preamble, randomly selecting the second preamble from a set of available preambles stored in the one or more memories of the device.

[0404] Clause 3: The method according to any one of Clauses 1 to 2, the method further comprising receiving a WUS while in a sleep state before receiving the first preamble, the WUS instructing the device to wake from the sleep state and monitor the first preamble.

[0405] Clause 4: The method described in Clause 3 further includes: receiving the WUS and the first preamble from the network entity or RF entity.

[0406] Clause 5: The method according to Clause 3, wherein: the WUS includes a group index, and the method further includes waking from the sleep state based on the group index and monitoring the first preamble in response to receiving the WUS.

[0407] Clause 6: The method according to Clause 5, wherein the device is pre-configured to monitor the preamble after receiving a WUS having the group index.

[0408] Clause 7: The method according to Clause 6 further includes: receiving a RA-RNTI assigned to the device, the RA-RNTI being associated with the group index.

[0409] Clause 8: The method according to Clause 3 further comprises: receiving a plurality of WUS, including the WUS, during one or more WUS monitoring intervals; determining one of the plurality of WUS by a random process to respond to, wherein the one WUS includes the WUS; and waking up and monitoring the first preamble based on the received WUS.

[0410] Clause 9: The method according to Clause 3, wherein: the WUS is a WUS dedicated to the device and instructs the device to wake up and monitor the first preamble, and the method further includes waking up and monitoring the first preamble based on receiving the WUS dedicated to the device.

[0411] Clause 10: The method described in Clause 3, wherein the WUS indicates that the transmission of the first preamble is enabled.

[0412] Clause 11: The method according to Clause 3, wherein the WUS includes an indication of a symbol index of the start symbol among the one or more first symbols.

[0413] Clause 12: The method according to Clause 3, wherein the timing offset is defined within the WUS.

[0414] Clause 13: The method according to any one of Clauses 1 to 12, wherein the timing offset is based on the position of the one or more first symbols in the time slot.

[0415] Clause 14: The method according to any one of Clauses 1 to 13, wherein the one or more first symbols include the symbol of the time slot and do not include the last symbol of the time slot.

[0416] Clause 15: The method according to any one of Clauses 1 to 14 further comprises: sending to the network entity at least one of the following: the timing resolution capability of the device or the frequency shift capability of the device.

[0417] Clause 16: The method according to Clause 15 further comprises: receiving from the network entity an indication that the device will synchronize the uplink communication between the device and the network entity based on the device's timing resolution capability or frequency shift capability after transmitting at least one of the device's timing resolution capability or frequency shift capability.

[0418] Clause 17: The method according to Clause 16 further includes: receiving a TA value from the network entity to be used for the uplink communication.

[0419] Clause 18: The method according to Clause 17, wherein the TA value is based at least in part on the timing error offset of the device.

[0420] Clause 19: The method according to Clause 16 further includes: receiving from the network entity a frequency compensation value for synchronizing the uplink communication.

[0421] Clause 20: The method according to Clause 15 further comprises: receiving from the network entity an indication that the network entity will synchronize the uplink communication between the device and the network entity after transmitting at least one of the timing resolution capability or the frequency shift capability of the device.

[0422] Clause 21: The method according to any one of Clauses 1 to 20, wherein: the carrier is intended for use with a plurality of network entities including the device, and the method further includes receiving from the network entity an indication that the device will synchronize the uplink communication between the device and the network entity.

[0423] Clause 22: The method according to any one of Clauses 1 to 21, wherein: the carrier is a dedicated signal intended only for use with the device, and the method further includes receiving from the network entity an indication that the network entity will synchronize the uplink communication between the device and the network entity.

[0424] Clause 23: The method according to any one of Clauses 1 to 22, wherein: the first preamble is received using a first frequency, the first backscattered signal is transmitted using a second frequency, and the second preamble is transmitted using the second frequency.

[0425] Clause 24: The method according to Clause 23 further includes: randomly selecting a frequency shift from a pre-configured set of frequency shifts at the device, wherein the second frequency differs from the first frequency by the frequency shift selected by the device.

[0426] Clause 25: The method of Clause 24 further comprises: determining a Random Access Radio Network Temporary Identifier (RA-RNTI) based on a randomly selected frequency shift.

[0427] Clause 26: The method according to Clause 23, wherein: the apparatus is configured using a frequency shift, and the second frequency differs from the first frequency by the frequency shift.

[0428] Clause 27: The method according to any one of Clauses 1 to 26, the method further comprising: receiving from the network entity an indication that the synchronization of the uplink communication between the device and the network entity has failed due to a conflict between the second preamble and at least one other preamble; and receiving from the network entity a message indicating a TA value to be used when sending another preamble.

[0429] Clause 28: The method according to any one of Clauses 1 to 27, wherein the second preamble includes a random access channel preamble, a simplified random access channel preamble, or another type of preamble.

[0430] Clause 29: The method according to any one of Clauses 1 to 28, wherein the device receives the first preamble after a periodic timer started after the initial access between the device and the network entity expires.

[0431] Clause 30: The method according to any one of Clauses 1 to 29, wherein the device receives the first preamble after a shift in the receive frequency or transmit frequency for communication with the uplink of the network entity or after receiving an instruction from the network entity intended solely for use by the device.

[0432] Clause 31: A method for wireless communication by a device, the method comprising: receiving a WUS in one or more first symbols while in a sleep state; transitioning from the sleep state to an awake state in response to receiving the WUS; and transmitting a carrier-based backscatter signal to a network entity in one or more second symbols, the backscatter signal including a preamble transmitted in response to receiving the WUS, wherein: the one or more second symbols are time-offset relative to the one or more first symbols based on a timing offset configured at the device and a timing error offset of the device, and the preamble is configured for synchronization of uplink communication between the device and the network entity.

[0433] Clause 32: The method described in Clause 31 further includes: receiving the WUS from the network entity or RF entity.

[0434] Clause 33: The method according to any one of Clauses 31 to 32, the method further comprising: in response to receiving the WUS, randomly selecting the preamble from a list of available preambles stored in the one or more memories of the device.

[0435] Clause 34: The method according to any one of Clauses 31 to 33, wherein: the WUS includes a group index, and the method further includes transitioning from the sleep state to the wake state based on the group index included in the WUS.

[0436] Clause 35: The method according to Clause 34, wherein the device is pre-configured to monitor the preamble from the network entity after receiving a WUS having the group index.

[0437] Clause 36: The method according to Clause 35 further includes: receiving a RA-RNTI assigned to the device, the RA-RNTI being associated with the group index.

[0438] Clause 37: The method according to any one of Clauses 31 to 36, the method further comprising: receiving a plurality of WUS, including the WUS, during one or more WUS monitoring intervals; determining one of the plurality of WUS by a random process to respond to, wherein the one WUS includes the WUS; and transitioning from the sleep state to the wake state.

[0439] Clause 38: The method according to any one of Clauses 31 to 37, wherein the WUS is a WUS specifically designed for the device.

[0440] Clause 39: The method according to any one of Clauses 31 to 38, wherein the WUS indicates that the transmission of another preamble by the network entity is disabled.

[0441] Clause 40: The method according to any one of Clauses 31 to 39, wherein the WUS includes an indication of a symbol index of the starting symbol among the one or more first symbols.

[0442] Clause 41: The method according to any one of Clauses 31 to 40, wherein the timing offset is defined in the WUS.

[0443] Clause 42: The method according to any one of Clauses 31 to 41, wherein the timing offset is based on the position of the one or more first symbols in the time slot.

[0444] Clause 43: The method according to any one of Clauses 31 to 42, wherein the one or more first symbols include the symbol of the time slot and do not include the last symbol of the time slot.

[0445] Clause 44: The method according to any one of Clauses 31 to 43 further comprises: sending to the network entity at least one of the following: the timing resolution capability of the device or the frequency shift capability of the device.

[0446] Clause 45: The method according to Clause 44 further comprises: receiving from the network entity an indication that the device will synchronize the uplink communication between the device and the network entity based on the device's timing resolution capability or frequency shift capability after transmitting at least one of the device's timing resolution capability or frequency shift capability.

[0447] Clause 46: The method according to Clause 45 further includes: receiving from the network entity a TA value to be used for synchronizing the uplink communication.

[0448] Clause 47: The method according to Clause 46, wherein the TA value is based at least in part on the timing error offset of the device.

[0449] Clause 48: The method according to any one of Clauses 31 to 47, wherein: the carrier is intended for use with a plurality of passive network devices including the device, and the method further includes receiving from the network entity an indication that the device will synchronize the uplink communication between the device and the network entity.

[0450] Clause 49: The method according to Clause 45 further includes: receiving from the network entity a frequency compensation value for synchronizing the uplink communication.

[0451] Clause 50: The method according to Clause 44 further comprises: receiving from the network entity an indication that the network entity will synchronize the uplink communication between the device and the network entity after transmitting at least one of the timing resolution capability or the frequency shift capability of the device.

[0452] Clause 51: The method described in Clause 50, wherein the carrier is a dedicated signal intended solely for use with the device.

[0453] Clause 52: The method according to any one of Clauses 31 to 51, wherein: the WUS is received using a first frequency, and the backscattered signal is transmitted using a second frequency.

[0454] Clause 53: The method according to Clause 52 further includes: randomly selecting a frequency shift from a pre-configured set of frequency shifts at the device, wherein the second frequency differs from the first frequency by the frequency shift selected by the device.

[0455] Clause 54: The method according to Clause 53 further includes: determining the Random Access Radio Network Temporary Identifier (RA-RNTI) based on a randomly selected frequency shift.

[0456] Clause 55: The method according to Clause 52, wherein: the apparatus is configured using a frequency shift, and the second frequency differs from the first frequency by the frequency shift.

[0457] Clause 56: The method according to any one of Clauses 31 to 55, the method further comprising: receiving from the network entity an indication that the synchronization of the uplink communication between the device and the network entity has failed due to a conflict between the preamble and at least one other preamble; and receiving from the network entity a message indicating a TA value to be used when sending another preamble.

[0458] Clause 57: The method according to any one of Clauses 31 to 56, wherein the preamble includes a random access channel preamble, a simplified random access channel preamble, or another type of preamble.

[0459] Clause 58: The method according to any one of Clauses 31 to 57, wherein the device receives the WUS after a periodic timer started after the initial access between the device and the network entity expires.

[0460] Clause 59: The method according to any one of Clauses 31 to 58, wherein the device receives the WUS after a shift in the receive frequency or transmit frequency used for communication with the uplink of the network entity or after receiving an instruction from the network entity intended solely for use by the device.

[0461] Clause 60: A method for wireless communication by a device, the method comprising: transmitting a first preamble to at least one passive network device in one or more first symbols; receiving a first backscattered signal for the first preamble from the at least one passive network device; calculating the RTT of the first preamble; receiving a second backscattered signal from the at least one passive network device in one or more second symbols, the second backscattered signal including a second preamble received in response to the transmission of the first preamble, wherein: the one or more second symbols are time-offset relative to the one or more first symbols, and the second preamble is configured for synchronization of uplink communication between the device and the at least one passive network device; determining a timing error offset of the at least one passive network device based on the time offset between the one or more first symbols and the one or more second symbols, the RTT of the first preamble, and a timing offset configured at the device; and calculating a TA value for uplink communication between the device and the at least one passive network device based on the RTT of the first preamble and the timing error offset of the at least one passive network device.

[0462] Clause 61: The method according to Clause 60 further includes: using the RTT to decode the second preamble.

[0463] Clause 62: The method according to any one of Clauses 60 to 61 further includes sending WUS before sending the first preamble.

[0464] Clause 63: The method described in Clause 62, wherein the WUS includes a group index.

[0465] Clause 64: The method described in Clause 62 further includes: sending multiple WUS, including the WUS.

[0466] Clause 65: The method described in Clause 62, wherein the WUS includes a WUS dedicated to a single passive network device.

[0467] Clause 66: The method according to Clause 62, wherein the WUS indicates that the transmission of the first preamble performed by the device is enabled.

[0468] Clause 67: The method according to Clause 62, wherein the WUS includes an indication of a symbol index of the start symbol among the one or more first symbols.

[0469] Clause 68: The method according to Clause 62, wherein the timing offset is defined within the WUS.

[0470] Clause 69: The method according to Clause 62, wherein the timing offset is based on the position of the one or more first symbols in the time slot.

[0471] Clause 71: The method according to Clause 62 further comprises: calculating RA-RNTI based on: the second preamble associated with the WUS and the frequency of the second preamble; scrambling a message indicating the TA value to be used for the uplink communication using the RA-RNTI; and sending the TA value to be used for the uplink communication to the at least one passive network device.

[0472] Clause 70: The method according to any one of Clauses 60 to 69, wherein the one or more first symbols include symbols of the time slot other than the last symbol of the time slot.

[0473] Clause 72: The method according to any one of Clauses 60 to 71 further comprises: receiving from the at least one passive network device at least one of the following: timing resolution capability of the at least one passive network device or frequency shift capability of the at least one passive network device.

[0474] Clause 73: The method according to Clause 72 further comprises: after receiving at least one of the timing resolution capability or the frequency shift capability of the at least one passive network device, sending to the at least one passive network device an indication that the at least one passive network device will synchronize the uplink communication between the device and the at least one passive network device based on the timing resolution capability or the frequency shift capability of the at least one passive network device.

[0475] Clause 74: The method according to Clause 73 further includes: sending the TA value to the at least one passive network device for synchronizing the uplink communication.

[0476] Clause 75: The method according to Clause 73 further includes: sending a frequency compensation value to the at least one passive network device for synchronizing the uplink communication.

[0477] Clause 76: The method according to Clause 72 further comprises: after receiving at least one of the timing resolution capability or the frequency shift capability of the at least one passive network device, sending an indication to the at least one passive network device that the device will synchronize the uplink communication between the device and the at least one passive network device based on the timing resolution capability or the frequency shift capability of the at least one passive network device.

[0478] Clause 77: The method according to Clause 76 further includes: transmitting one or more signals to the at least one passive network device using a frequency based on a frequency shift.

[0479] Clause 78: The method according to Clause 76 further includes: receiving the uplink communication from the at least one passive network device using a frequency based on a frequency shift.

[0480] Clause 79: The method according to any one of Clauses 60 to 78, wherein: the first preamble is transmitted using a first frequency, the first backscatter signal is received from the at least one passive network device using a second frequency, and the second backscatter signal is received using the second frequency.

[0481] Clause 80: The method according to Clause 79 further comprises: configuring the at least one passive network device using a frequency shift, wherein the second frequency differs from the first frequency by the frequency shift.

[0482] Clause 81: The method according to any one of Clauses 60 to 80, the method further comprising: transmitting a third preamble to the at least one passive network device in one or more third symbols; receiving a third backscattered signal for the third preamble from the at least one passive network device; calculating a second RTT of the third preamble; receiving a fourth backscattered signal including a fourth preamble from the at least one passive network device in one or more fourth symbols in response to transmitting the third preamble, wherein: the one or more fourth symbols are time-offset relative to the one or more third symbols, and the fourth preamble is configured for synchronization of uplink communication between the device and the at least one passive network device; and determining that the fourth preamble conflicts with at least one other preamble transmitted by at least one other passive network device.

[0483] Clause 82: The method according to Clause 81 further includes: sending an indication to the at least one passive network device regarding the synchronization failure of the uplink communication between the device and the at least one passive network device based on determining that the fourth preamble conflicts with the at least one other preamble.

[0484] Clause 83: The method according to Clause 81 further comprises: calculating a second TA value based on a minimum RTT and a minimum timing error offset associated with the at least one passive network device or the at least one other passive network device; and sending the second TA value to be used when transmitting another preamble to the at least one passive network device.

[0485] Clause 84: The method according to Clause 81, wherein determining that the fourth preamble conflicts with the at least one other preamble includes detecting multiple related peaks.

[0486] Clause 85: The method according to any one of Clauses 60 to 84, wherein the second preamble comprises a random access channel preamble, a simplified random access channel preamble, or another type of preamble.

[0487] Clause 86: The method according to any one of Clauses 60 to 85, the method further comprising: sending the first preamble after the expiration of a periodic timer started after the initial access between the device and the at least one passive network device or after sending an indication to the at least one passive network device, wherein the indication is a dedicated signal.

[0488] Clause 87: The method according to any one of Clauses 60 to 86, wherein before sending the first preamble, the method further includes determining that the uplink communication from the at least one passive network device deviates from the expected uplink communication in time or frequency by at least a threshold amount.

[0489] Clause 88: The method according to any one of Clauses 60 to 87, wherein before transmitting the first preamble, the method further includes detecting frequency shift in the uplink communication from the at least one passive network device.

[0490] Clause 89: A method for wireless communication by a device, the method comprising: transmitting a WUS to at least one passive network device in one or more first symbols while in a sleep state; receiving a backscattered signal from the at least one passive network device in one or more second symbols, the backscattered signal including a preamble received in response to the transmission of the WUS, wherein: the one or more second symbols are time-offset relative to the one or more first symbols, and the preamble is configured for synchronization of uplink communication between the device and the at least one passive network device; determining a timing error offset of the at least one passive network device based on the time offset between the one or more first symbols and the one or more second symbols and a timing offset configured at the at least one passive network device; and calculating a TA value for the uplink communication based on the timing error offset.

[0491] Clause 90: The method described in Clause 89, wherein the WUS includes a group index.

[0492] Clause 91: The method according to any one of Clauses 89 to 90 further includes: sending a plurality of WUS including the WUS.

[0493] Clause 92: The method according to any one of Clauses 89 to 91, wherein the WUS includes a WUS dedicated to a single passive network device.

[0494] Clause 93: The method according to any one of Clauses 89 to 92, wherein the WUS indicates that the transmission of another preamble by the device is disabled.

[0495] Clause 94: The method according to any one of Clauses 89 to 93, wherein the WUS includes an indication of a symbol index of the starting symbol among the one or more first symbols.

[0496] Clause 95: The method according to any one of Clauses 89 to 94, wherein the timing offset is defined within the WUS.

[0497] Clause 96: The method according to any one of Clauses 89 to 95, wherein the timing offset is based on the position of the one or more first symbols in the time slot.

[0498] Clause 97: The method according to any one of Clauses 89 to 96, wherein the one or more first symbols include symbols of the time slot other than the last symbol of the time slot.

[0499] Clause 98: The method according to any one of Clauses 89 to 97, the method further comprising: calculating RA-RNTI based on: the preamble associated with the WUS and the frequency of the preamble; scrambling a message indicating the TA value to be used for the uplink communication using the RA-RNTI; and sending the TA value to be used for the uplink communication to the at least one passive network device.

[0500] Clause 99: The method according to any one of Clauses 89 to 98 further comprises: receiving from the at least one passive network device at least one of the following: timing resolution capability of the at least one passive network device or frequency shift capability of the at least one passive network device.

[0501] Clause 100: The method according to Clause 99 further comprises: after receiving at least one of the timing resolution capability or the frequency shift capability of the at least one passive network device, sending to the at least one passive network device an indication that the at least one passive network device will synchronize the uplink communication between the device and the at least one passive network device based on the timing resolution capability or the frequency shift capability of the at least one passive network device.

[0502] Clause 101: The method according to Clause 100 further includes: sending the TA value to the at least one passive network device for synchronizing the uplink communication.

[0503] Clause 102: The method according to Clause 100 further includes: sending a frequency compensation value to the at least one passive network device for synchronizing the uplink communication.

[0504] Clause 103: The method according to Clause 99 further comprises: after receiving at least one of the timing resolution capability or the frequency shift capability of the at least one passive network device, sending to the at least one passive network device an indication that the device will synchronize the uplink communication between the device and the at least one passive network device based on the timing resolution capability or the frequency shift capability of the at least one passive network device.

[0505] Clause 104: The method according to Clause 103 further includes: transmitting one or more signals to the at least one passive network device using a frequency based on a frequency shift.

[0506] Clause 105: The method according to Clause 103 further includes: receiving the uplink communication from the at least one passive network device using a frequency based on a frequency shift.

[0507] Clause 106: The method according to any one of Clauses 89 to 105, wherein: the WUS is transmitted using a first frequency, and the backscattered signal is received using a second frequency.

[0508] Clause 107: The method according to Clause 106 further includes: configuring the at least one passive network device using a frequency shift, wherein the second frequency differs from the first frequency by the frequency shift.

[0509] Clause 108: The method according to any one of Clauses 89 to 107, the method further comprising: transmitting a second WUS to the at least one passive network device in one or more third symbols; receiving a second backscattered signal from the at least one passive network device in one or more fourth symbols, the second backscattered signal including a second preamble received in response to the transmission of the second WUS, wherein: the one or more fourth symbols are time-offset relative to the one or more third symbols, and the second preamble is configured for synchronization of uplink communication between the device and the at least one passive network device; and determining that the second preamble conflicts with at least one other preamble transmitted by at least one other passive network device.

[0510] Clause 109: The method according to Clause 108 further includes: sending an indication to the at least one passive network device regarding the synchronization failure of the uplink communication between the device and the at least one passive network device based on determining that the second preamble conflicts with the at least one other preamble sent by the at least one other passive network device.

[0511] Clause 110: The method according to Clause 108 further includes: calculating a second TA value based on a minimum timing error offset associated with the at least one passive network device or the at least one other passive network device; and sending the second TA value to be used when transmitting a third preamble to the at least one passive network device.

[0512] Clause 111: The method according to Clause 108, wherein determining that the second preamble conflicts with the at least one other preamble sent by the at least one other passive network device includes detecting multiple related peaks.

[0513] Clause 112: The method according to any one of Clauses 89 to 111, wherein the preamble includes a random access channel preamble, a simplified random access channel preamble, or another type of preamble.

[0514] Clause 113: The method according to any one of Clauses 89 to 112, the method further comprising: sending the WUS after the expiration of a periodic timer started after the initial access between the device and the at least one passive network device or after sending an indication to the at least one passive network device, wherein the indication is a dedicated signal.

[0515] Clause 114: The method according to any one of Clauses 89 to 113, wherein prior to sending the WUS, the method further includes determining that the uplink communication from the at least one passive network device deviates from the expected uplink communication in time or frequency by at least a threshold amount.

[0516] Clause 115: The method according to any one of Clauses 89 to 114, wherein prior to transmitting the WUS, the method further includes detecting frequency shift in the uplink communication from the at least one passive network device.

[0517] Clause 116: A method for wireless communication by a device, the method comprising: receiving a backscattered signal from at least one passive network device in one or more first symbols, the backscattered signal including a first preamble transmitted by an RF entity to the at least one passive network device; determining an RTT of the first preamble; receiving a second backscattered signal including a second preamble from the at least one passive network device in one or more second symbols, wherein: the one or more second symbols are time-offset relative to the one or more first symbols, and the second preamble is configured for synchronization of uplink communication between the device and the at least one passive network device; determining a timing error offset of the at least one passive network device based on the time offset between the one or more first symbols and the one or more second symbols, the RTT of the first preamble, and a timing offset configured at the device; and calculating a TA value for the uplink communication between the device and the at least one passive network device based on the RTT of the first preamble and the timing error offset of the at least one passive network device.

[0518] Clause 117: The method according to Clause 116 further includes: using the RTT to decode the second preamble.

[0519] Clause 118: The method according to any one of Clauses 116 to 117 further comprises: receiving from the at least one passive network device at least one of the following: timing resolution capability of the at least one passive network device or frequency shift capability of the at least one passive network device.

[0520] Clause 119: The method according to Clause 118 further comprises: after receiving at least one of the timing resolution capability or the frequency shift capability of the at least one passive network device, sending to the at least one passive network device an indication that the at least one passive network device will synchronize the uplink communication between the device and the at least one passive network device based on the timing resolution capability or the frequency shift capability of the at least one passive network device.

[0521] Clause 120: The method according to Clause 119 further includes: sending the TA value to the at least one passive network device for synchronizing the uplink communication.

[0522] Clause 121: The method according to Clause 119 further includes: sending a frequency compensation value to the at least one passive network device for synchronizing the uplink communication.

[0523] Clause 122: The method according to Clause 118 further comprises: after receiving at least one of the timing resolution capability or the frequency shift capability of the at least one passive network device, sending to the at least one passive network device an indication that the device will synchronize the uplink communication between the device and the at least one passive network device based on the timing resolution capability or the frequency shift capability of the at least one passive network device.

[0524] Clause 123: The method according to Clause 122 further includes: transmitting one or more signals to the at least one passive network device using a frequency based on a frequency shift.

[0525] Clause 124: The method according to Clause 122 further includes: receiving the uplink communication from the at least one passive network device using a frequency based on a frequency shift.

[0526] Clause 125: The method according to any one of Clauses 116 to 124, the method further comprising: receiving a third backscattered signal from the at least one passive network device in one or more third symbols, the third backscattered signal including a third preamble transmitted by the RF entity to the at least one passive network device; calculating a second RTT of the third preamble; receiving a fourth backscattered signal including a fourth preamble from the at least one passive network device in one or more fourth symbols, wherein: the one or more fourth symbols are time-offset relative to the one or more third symbols, and the fourth preamble is configured for synchronization of the uplink communication between the device and the at least one passive network device; and determining that the fourth preamble conflicts with at least one other preamble transmitted by at least one other passive network device.

[0527] Clause 126: The method according to Clause 125 further includes: sending an indication to the at least one passive network device regarding the synchronization failure of the uplink communication between the device and the at least one passive network device based on determining that the fourth preamble conflicts with the at least one other preamble.

[0528] Clause 127: The method according to Clause 125 further includes: calculating a second TA value based on a minimum RTT and a minimum timing error offset associated with the at least one passive network device or the at least one other passive network device; and sending the second TA value to be used when transmitting another preamble to the at least one passive network device.

[0529] Clause 128: The method according to Clause 126, wherein determining that the fourth preamble conflicts with the at least one other preamble includes detecting multiple related peaks.

[0530] Clause 129: The method according to any one of Clauses 116 to 128, wherein the second preamble includes a random access channel preamble, a simplified random access channel preamble, or another type of preamble.

[0531] Clause 130: A method for wireless communication by a device, the method comprising: determining that an RF entity transmits a WUS to at least one passive network device in one or more first symbols; receiving a backscattered signal from the at least one passive network device in one or more second symbols, the backscattered signal including a preamble received in response to the transmission of the WUS by the RF entity, wherein: the one or more second symbols are time-offset relative to the one or more first symbols, and the preamble is configured for synchronization of uplink communication between the device and the at least one passive network device; determining a timing error offset of the at least one passive network device based on the time offset between the one or more first symbols and the one or more second symbols and a timing offset configured at the at least one passive network device; and calculating a TA value for the uplink communication based on the timing error offset.

[0532] Clause 131: The method according to Clause 130 further comprises: calculating RA-RNTI based on: the preamble associated with the WUS and the frequency of the preamble; scrambling a message indicating the TA value to be used for the uplink communication using the RA-RNTI; and sending the TA value to be used for the uplink communication to the at least one passive network device.

[0533] Clause 132: The method according to any one of Clauses 130 to 131 further comprises: receiving from the at least one passive network device at least one of the following: timing resolution capability of the at least one passive network device or frequency shift capability of the at least one passive network device.

[0534] Clause 133: The method according to Clause 132 further comprises: after receiving at least one of the timing resolution capability or the frequency shift capability of the at least one passive network device, sending to the at least one passive network device an indication that the at least one passive network device will synchronize the uplink communication between the device and the at least one passive network device based on the timing resolution capability or the frequency shift capability of the at least one passive network device.

[0535] Clause 134: The method according to Clause 133 further includes: sending the TA value to the at least one passive network device for synchronizing the uplink communication.

[0536] Clause 135: The method according to Clause 133 further includes: sending a frequency compensation value to the at least one passive network device for synchronizing the uplink communication.

[0537] Clause 136: The method according to Clause 132 further comprises: after receiving at least one of the timing resolution capability or the frequency shift capability of the at least one passive network device, sending an indication to the at least one passive network device that the device will synchronize the uplink communication between the device and the at least one passive network device based on the timing resolution capability or the frequency shift capability of the at least one passive network device.

[0538] Clause 137: The method according to Clause 136 further includes: transmitting one or more signals to the at least one passive network device using a frequency based on a frequency shift.

[0539] Clause 138: The method according to Clause 136 further includes: receiving the uplink communication from the at least one passive network device using a frequency based on a frequency shift.

[0540] Clause 139: The method according to Clause 136 further comprises: configuring the at least one passive network device using a frequency shift, wherein the backscattered signal is received using a frequency based on the frequency shift.

[0541] Clause 140: The method according to any one of Clauses 130 to 139, the method further comprising: determining that the RF entity transmitted a second WUS to the at least one passive network device in one or more third symbols; receiving a second backscattered signal from the at least one passive network device in one or more fourth symbols, the second backscattered signal including a second preamble received in response to the transmission of the second WUS, wherein: the one or more fourth symbols are time-offset relative to the one or more third symbols, and the second preamble is configured for synchronization of uplink communication between the device and the at least one passive network device; and determining that the second preamble conflicts with at least one other preamble transmitted by at least one other passive network device.

[0542] Clause 141: The method according to Clause 140 further includes: sending an indication to the at least one passive network device regarding the synchronization failure of the uplink communication between the device and the at least one passive network device based on determining that the second preamble conflicts with the at least one other preamble sent by the at least one other passive network device.

[0543] Clause 142: The method according to Clause 140 further includes: calculating a second TA value based on a minimum timing error offset associated with the at least one passive network device or the at least one other passive network device; and sending the second TA value to be used when transmitting a third preamble to the at least one passive network device.

[0544] Clause 143: The method according to Clause 140, wherein determining that the second preamble conflicts with the at least one other preamble sent by the at least one other passive network device includes detecting multiple related peaks.

[0545] Clause 144: The method according to any one of Clauses 130 to 143, wherein the preamble includes a random access channel preamble, a simplified random access channel preamble, or another type of preamble.

[0546] Clause 145: One or more means comprising: one or more memories including executable instructions; and one or more processors configured to execute the executable instructions and cause the one or more means to perform the method according to any one of Clauses 1 to 144.

[0547] Clause 146: One or more apparatuses, said apparatuses comprising components for performing the method according to any one of Clauses 1 to 144.

[0548] Clause 147: One or more non-transitory computer-readable media, the one or more non-transitory computer-readable media comprising executable instructions that, when executed by one or more processors of one or more devices, cause the one or more devices to perform the method according to any one of Clauses 1 to 144.

[0549] Clause 148: One or more computer program products embodied on one or more computer-readable storage media, the one or more computer-readable storage media including code for performing the method according to any one of Clauses 1 to 144. Additional Notes

[0550] 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 function and arrangement of the elements discussed may be changed without departing from the scope of this disclosure. Various processes or components may be omitted, substituted, or added as appropriate in the various examples. For example, the described methods may be performed in a different order than described, and various actions may be added, omitted, or combined. Furthermore, features described with respect to some examples may be combined in some other examples. For example, any number of aspects set forth herein may be used to implement an apparatus or practice. Additionally, the scope of this disclosure is intended to cover such apparatuses or methods practiced using other structures, functionalities, or structures and functionalities that complement or replace the various aspects of this 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.

[0551] The various exemplary logic blocks, modules, and circuits described in this disclosure can be implemented or executed using a general-purpose processor, AI processor, digital signal processor (DSP), ASIC, field-programmable gate array (FPGA) or other programmable logic device (PLD), discrete gate or transistor logic unit, discrete hardware component, or any combination thereof designed to perform the functions described herein. While the general-purpose processor may be a microprocessor, in alternative embodiments, 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, such as a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors working in conjunction with a DSP core, a system-on-a-chip (SoC), or any other such configuration.

[0552] As used in this article, the phrase “at least one of the items” refers to any combination of these items, including a single member. As an example, “at least one of a, b, or c” is intended to cover: a, b, c, ab, ac, bc, and abc, as well as any combination with multiple identical elements (e.g., aa, aaa, aab, aac, abb, acc, bb, bbb, bbb, cc, and ccc, or any other ordering of a, b, and c).

[0553] As used herein, the term "determine" encompasses a wide variety of actions. For example, "determine" can include calculation, operation, processing, deduction, investigation, lookup (e.g., searching in a table, database, or other data structure), assertion, etc. Additionally, "determine" can include receiving (e.g., receiving information), accessing (e.g., accessing data in memory), etc. Furthermore, "determine" can include parsing, selecting, picking, building, etc.

[0554] As used herein, unless otherwise stated, “coupled to” and “coupled with” generally encompass both direct and indirect coupling (e.g., including intermediate aspects of coupling). For example, stating that a processor is coupled to memory allows for direct coupling or coupling via an intermediate aspect such as a bus.

[0555] The methods disclosed herein include one or more actions for implementing the methods. These method actions may be interchanged without departing from the scope of the claims. In other words, unless a specified order of actions is given, the order and / or use of a particular action may be modified without departing from the scope of the claims. Furthermore, the various operations of the methods described above can be performed by any suitable component capable of performing the corresponding function. This component may include various hardware and / or software components and / or modules, including but not limited to circuits, application-specific integrated circuits (ASICs), or processors.

[0556] The following claims are not intended to be limited to the aspects shown herein, but should be given the full scope consistent with the language of the claims. References to singular elements are not intended to mean “only one” (unless specifically stated as “only one”), but rather “one or more”. Unless otherwise specified, definite articles (e.g., “the” or “described”) subsequently used with an element (e.g., “processor”) are not intended to give that element a singular meaning (e.g., “only one”). For example, unless otherwise specified, references to elements (e.g., “processor”, “controller”, “memory”, “transceiver”, “antenna”, “the processor”, “the controller”, “the memory”, “the transceiver”, “the antenna”, etc.) should be understood to refer to one or more elements (e.g., “one or more processors”, “one or more controllers”, “one or more memories”, “a plurality of transceivers”, etc.). The terms “set” and “group” are intended to include one or more elements and may be used interchangeably with “one or more”. In the case of references to one or more elements performing a function (e.g., steps of a method), one element may perform all the functions, or more than one element may collectively perform those functions. When more than one element performs these functions together, each function does not need to be performed by every single element (e.g., different functions can be performed by different elements), and / or each function does not need to be performed by only one element as a whole (e.g., different elements can perform different sub-functions of a function). Similarly, when referring to one or more elements configured to cause another element (e.g., a device) to perform a function, one element may be configured to cause another element to perform all functions, or more than one element may be jointly configured to cause another element to perform these functions. Unless otherwise specifically stated, the term "some" refers to one or more. All structural and functional equivalents of the elements of the various aspects described throughout this disclosure that are currently or hereafter known to those skilled in the art are intended to be covered by the claims. Furthermore, nothing disclosed herein is intended to be offered to the public, whether or not such disclosure is explicitly recited in the claims.

Claims

1. An apparatus configured for wireless communication, the apparatus comprising: one or more memories including processor-executable instructions; and one or more processors configured to execute the processor-executable instructions and cause the apparatus to: receive a first preamble in one or more first symbols; transmit a first backscatter signal to a network entity based on the first preamble; and transmit a second backscatter signal based on a carrier to the network entity in one or more second symbols, the second backscatter signal including a second preamble, the second backscatter signal being transmitted in response to receiving the first preamble, wherein: the one or more second symbols are offset in time relative to the one or more first symbols based on a timing offset configured at the apparatus and a timing error offset of the apparatus, and the second preamble is configured for synchronization of uplink communications between the apparatus and the network entity.

2. The apparatus of claim 1, wherein the one or more processors are configured to execute the processor-executable instructions and cause the apparatus to randomly select the second preamble from a set of available preambles stored in the one or more memories of the apparatus in response to receiving the first preamble.

3. The apparatus of claim 1, wherein the one or more processors are configured to execute the processor-executable instructions and cause the apparatus to receive a wake-up signal (WUS) while in a sleep state prior to receiving the first preamble, the WUS indicating the apparatus to wake up from the sleep state and monitor for the first preamble.

4. The apparatus of claim 3, wherein the one or more processors are configured to execute the processor-executable instructions and cause the apparatus to receive the WUS and the first preamble from the network entity or a radio frequency (RF) entity.

5. The apparatus of claim 3, wherein: the WUS includes a group index, and the one or more processors are configured to execute the processor-executable instructions and cause the apparatus to wake up from the sleep state and monitor for the first preamble based on the group index in response to receiving the WUS.

6. The apparatus of claim 5, wherein the apparatus is preconfigured to monitor for a preamble after receiving a WUS having the group index.

7. The apparatus of claim 6, wherein the one or more processors are configured to execute the processor-executable instructions and cause the apparatus to receive a random access radio network temporary identity (RA-RNTI) assigned to the apparatus, the RA-RNTI being associated with the group index.

8. The apparatus of claim 3, wherein the one or more processors are configured to execute the processor-executable instructions and cause the apparatus to: receive a plurality of WUSs including the WUS during one or more WUS monitoring intervals; determining, by a random process, one of the plurality of WUSs to respond to, wherein the one WUS comprises the WUS; and waking up and monitoring the first preamble based on receiving the WUS.

9. The apparatus of claim 3, wherein: the WUS is a WUS specific to the apparatus and indicates that the apparatus is to wake up and monitor the first preamble, and the one or more processors are configured to execute the processor-executable instructions and cause the apparatus to wake up and monitor the first preamble based on receiving the WUS specific to the apparatus.

10. The apparatus of claim 3, wherein the WUS indicates that transmission of the first preamble is enabled.

11. The apparatus of claim 3, wherein the WUS comprises an indication of a symbol index of a starting symbol in the one or more first symbols.

12. The apparatus of claim 3, wherein the timing offset is defined within the WUS.

13. The apparatus of claim 1, wherein the timing offset is based on a location of the one or more first symbols in a slot.

14. The apparatus of claim 1, wherein the one or more first symbols comprise symbols of a slot and exclude a last symbol of the slot.

15. The apparatus of claim 1, wherein the one or more processors are configured to execute the processor-executable instructions and cause the apparatus to transmit, to the network entity, at least one of: a timing resolution capability of the apparatus, or a frequency shift capability of the apparatus.

16. The apparatus of claim 15, wherein the one or more processors are configured to execute the processor-executable instructions and cause the apparatus to receive, from the network entity, an indication that the apparatus is to synchronize the uplink communication between the apparatus and the network entity based on one of the timing resolution capability of the apparatus or the frequency shift capability of the apparatus after transmitting the at least one of the timing resolution capability of the apparatus or the frequency shift capability of the apparatus.

17. The apparatus of claim 16, wherein: the one or more processors are configured to execute the processor-executable instructions and cause the apparatus to receive, from the network entity, a timing advance (TA) value to use for the uplink communication, and the TA value is based at least in part on the timing error offset of the apparatus.

18. The apparatus of claim 17, wherein the one or more processors are configured to execute the processor-executable instructions and cause the apparatus to receive, from the network entity, a frequency compensation value to use for synchronizing the uplink communication.

19. The apparatus of claim 15, wherein the one or more processors are configured to execute the processor-executable instructions, and cause the apparatus to receive, from the network entity, an indication that the network entity is to synchronize the uplink communications between the apparatus and the network entity after transmitting at least one of the timing resolution capability of the apparatus or the frequency shift capability of the apparatus.

20. The apparatus of claim 1, wherein the one or more processors are configured to execute the processor-executable instructions, and cause the apparatus to: receive, from the network entity, an indication that the apparatus is to synchronize the uplink communications between the apparatus and the network entity when the carrier is intended for a plurality of network entities including the apparatus; and receive, from the network entity, an indication that the network entity is to synchronize the uplink communications between the apparatus and the network entity when the carrier is a dedicated signal intended only for the apparatus.

21. The apparatus of claim 1, wherein: the first preamble is received using a first frequency, the first backscatter signal is transmitted using a second frequency, and the second preamble is transmitted using the second frequency.

22. The apparatus of claim 21, wherein: the one or more processors are configured to execute the processor-executable instructions, and cause the apparatus to randomly select a frequency shift amount from a set of frequency shift amounts pre-configured at the apparatus, wherein the second frequency differs from the first frequency by the frequency shift amount selected by the apparatus.

23. The apparatus of claim 22, wherein the one or more processors are configured to execute the processor-executable instructions, and cause the apparatus to determine a random access radio network temporary identity (RA-RNTI) based on the randomly selected frequency shift amount.

24. The apparatus of claim 21, wherein: the apparatus is configured with a frequency shift amount, and the second frequency differs from the first frequency by the frequency shift amount.

25. The apparatus of claim 1, wherein the one or more processors are configured to execute the processor-executable instructions, and cause the apparatus to: receive, from the network entity, an indication that the synchronization of the uplink communications between the apparatus and the network entity failed due to a collision of the second preamble with at least one other preamble; and receive, from the network entity, a message indicating a timing advance (TA) value to use when transmitting another preamble.

26. The apparatus of claim 1, wherein the second preamble comprises a random access channel preamble, a simplified random access channel preamble, or another type of preamble.

27. The apparatus of claim 1, wherein the apparatus receives the first preamble: after expiration of a periodic timer initiated after initial access between the apparatus and the network entity, after a shift in a receive frequency or a transmit frequency used for the uplink communications with the network entity, or after a shift in a receive frequency or a transmit frequency used for the uplink communications with the network entity. after receiving an indication from the network entity that is intended only for the apparatus.

28. An apparatus configured for wireless communication, the apparatus comprising: one or more memories including processor-executable instructions; and one or more processors configured to execute the processor-executable instructions and cause the apparatus to: transmit a first preamble in one or more first symbols to at least one passive network device; receive a first backscatter signal from the at least one passive network device for the first preamble; calculate a round trip time (RTT) for the first preamble, receive a second backscatter signal from the at least one passive network device in one or more second symbols, the second backscatter signal including a second preamble received in response to transmission of the first preamble, wherein: the one or more second symbols are offset in time relative to the one or more first symbols, and the second preamble is configured for synchronization of uplink communications between the apparatus and the at least one passive network device; determine a timing error offset of the at least one passive network device based on an amount of offset in time between the one or more first symbols and the one or more second symbols, the RTT for the first preamble, and a timing offset configured at the apparatus; and calculate a timing advance (TA) value for uplink communications between the apparatus and the at least one passive network device based on the RTT for the first preamble and the timing error offset of the at least one passive network device.

29. An apparatus configured for wireless communication, the apparatus comprising: one or more memories including processor-executable instructions; and one or more processors configured to execute the processor-executable instructions and cause the apparatus to: receive a backscatter signal from at least one passive network device in one or more first symbols, the backscatter signal including a first preamble transmitted to the at least one passive network device by a radio frequency (RF) entity; determine a round trip time (RTT) for the first preamble, receive a second backscatter signal from the at least one passive network device including a second preamble in one or more second symbols, wherein: the one or more second symbols are offset in time relative to the one or more first symbols, and the second preamble is configured for synchronization of uplink communications between the apparatus and the at least one passive network device; determine a timing error offset of the at least one passive network device based on an amount of offset in time between the one or more first symbols and the one or more second symbols, the RTT for the first preamble, and a timing offset configured at the apparatus; and calculating a timing advance (TA) value for the uplink communications between the apparatus and the at least one passive network device based on the RTT of the first preamble and the timing error offset of the at least one passive network device.

30. A method for wireless communication by an apparatus, the method comprising: receiving a first preamble in one or more first symbols; sending a first backscatter signal to a network entity based on the first preamble; and sending a second backscatter signal based on a carrier to the network entity in one or more second symbols, the second backscatter signal including a second preamble, the second backscatter signal being sent in response to receiving the first preamble, wherein: the one or more second symbols are offset in time relative to the one or more first symbols based on a timing offset configured at the apparatus and a timing error offset of the apparatus, and the second preamble is configured for synchronization of uplink communications between the apparatus and the network entity.

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