Carrier design using environmental internet of things resource sets and multiplexing process for different environmental internet of things devices

Abstract

The invention relates to carrier design using a set of environmental Internet of Things resources and a multiplexing process of different environmental Internet of Things devices. Systems and methods for carrier design using an environmental Internet of Things (IoT) resource set and multiplexing of different environmental IoT devices are discussed herein. The base station sends a trigger message identifying the first environment IoT resource set to the first environment IoT tag; receiving, in a first resource of the first set of ambient IoT resources, a first backscatter derived from a carrier by the first ambient IoT tag; and decoding first data of the first environment IoT tag from the first backscatter. The environment IoT tag receives a trigger message identifying the environment IoT resource set from the base station; receiving carriers in the environmental IoT resource set; and generating backscatter in resources of the set of environmental IoT resources using the carrier.

Description

Technical Field

[0001] The present application generally relates to wireless communication systems, including systems that implement ambient Internet of Things (IoT) transmissions. Background Art

[0002] Wireless mobile communication technologies use various standards and protocols to transmit data between base stations and wireless communication devices. For example, wireless communication system standards and protocols may include, for example, the Third Generation Partnership Project (3GPP) Long Term Evolution (LTE) (e.g., 4G), 3GPP New Radio (NR) (e.g., 5G), and the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard for wireless local area networks (WLANs) (commonly referred to within industry organizations as IEEE). ).

[0003] As envisioned by 3GPP, different wireless communication system standards and protocols may use various radio access networks (RANs) for communication between base stations (sometimes also referred to as RAN nodes, network nodes, or simply nodes) of the RAN and wireless communication devices, known as user equipment (UE). 3GPP RANs may include, for example, Global System for Mobile Communications (GSM), Enhanced Data for GSM Evolution (EDGE) RAN (GERAN), Universal Terrestrial Radio Access Network (UTRAN), Evolved Universal Terrestrial Radio Access Network (E-UTRAN), and / or Next Generation Radio Access Network (NG-RAN).

[0004] Each RAN can use one or more radio access technologies (RATs) to perform communications between base stations and UEs. For example, GERAN implements GSM and / or EDGE RATs, UTRAN implements Universal Mobile Telecommunications System (UMTS) RATs or other 3GPP RATs, E-UTRAN implements LTE RATs (sometimes referred to as LTE), and NG-RAN implements NR RATs (the NR RATs are sometimes referred to herein as 5G RATs, 5G NR RATs, or simply NR). In some deployments, E-UTRAN may also implement NR RATs. In some deployments, NG-RAN may also implement LTE RATs.

[0005] The base stations used by the RAN may correspond to the RAN. An example of an E-UTRAN base station is an Evolved Universal Terrestrial Radio Access Network (E-UTRAN) Node B (often also denoted as an evolved Node B, enhanced Node B, eNodeB, or eNB). An example of an NG-RAN base station is a Next Generation Node B (sometimes also referred to as a gNode B or gNB).

[0006] The RAN provides communication services with external entities through its connection to the Core Network (CN). For example, E-UTRAN may utilize the Evolved Packet Core (EPC), while NG-RAN may utilize the 5G Core Network (5GC).

[0007] The frequency bands of 5G NR can be divided into two or more different frequency ranges. For example, frequency range 1 (FR1) may include frequency bands operating at frequencies below 6 gigahertz (GHz), some of which may be used by previous standards and may potentially be expanded to cover new spectrum products from 410 megahertz (MHz) to 7125 MHz. Frequency range 2 (FR2) may include frequency bands from 24.25 GHz to 52.6 GHz. Note that in some systems, FR2 may also include frequency bands from 52.6 GHz to 71 GHz (or higher). The frequency bands in the millimeter wave (mmWave) range of FR2 may have smaller coverage but potentially higher available bandwidth than the frequency bands in FR1. Technicians will recognize that these frequency ranges, provided by way of example, may vary over time or across regions. Summary of the Invention

[0008] A method of a base station is provided herein, the method comprising: sending a trigger message identifying a first set of environmental IoT resources to a first environmental IoT tag; receiving first backscatter derived from a carrier by the first environmental IoT tag in a first resource of the first set of environmental IoT resources; and decoding first data of the first environmental IoT tag from the first backscatter.

[0009] This document also provides a method for an ambient Internet of Things (IoT) tag, the method comprising: receiving a trigger message identifying a first ambient IoT resource set from a first base station; receiving a carrier in the first ambient IoT resource set; and generating a first backscatter in a first resource of the first ambient IoT resource set using the carrier.

[0010] Also provided herein is an apparatus comprising means for performing the method herein.

[0011] A computer-readable medium is also provided herein, comprising instructions that, when executed by one or more processors of an electronic device, cause the electronic device to perform the method herein.

[0012] Also provided herein is an apparatus comprising logic components, modules, or circuits for performing the methods herein.

[0013] The present invention also provides a baseband processor for a base station, wherein the baseband processor is configured to cause the base station to execute one or more elements of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] To easily identify the discussion of any particular element or act, the most significant digit(s) in a reference number refers to the drawing number that first introduces the element.

[0015] Figure 1 Examples of carrier transmission and backscatter are illustrated.

[0016] Figure 2 An example of multiple access between a base station and multiple environmental IoT tags according to the embodiments of this document is illustrated.

[0017] Figure 3 An example of multiple access as between a base station and a plurality of environmental IoT tags according to embodiments herein is illustrated, wherein carriers are provided to the environmental IoT tags by various UEs.

[0018] Figure 4 An example process for generating backscatter of a carrier wave at an ambient IoT tag according to embodiments herein is illustrated, where the carrier wave is received from a base station.

[0019] Figure 5 An example process of selecting UL resources from a resource pool and for simultaneous use by generating backscatter of a carrier at a lower category ambient IoT tag and a higher category ambient IoT tag performing self-powered transmission according to embodiments herein is illustrated.

[0020] Figure 6 An example process for generating a backscatter carrier according to embodiments herein is illustrated, where the carrier is received from a UE or a secondary device.

[0021] Figure 7 An example process for generating backscatter that is both FDM and CDM according to embodiments herein is illustrated, and wherein an ambient IoT tag selects resources for performing backscatter from an ambient IoT resource library.

[0022] Figure 8A A first example of lower category IoT tag usage is illustrated where interference may affect signaling.

[0023] Figure 8B A second example of lower category IoT tag usage is illustrated where interference may affect signaling.

[0024] Figure 9 Examples of UL packet formats according to various preamble lengths according to embodiments of this document are illustrated.

[0025] Figure 10Examples of UL packet formats with varying preamble lengths using OOK transmission according to embodiments herein are illustrated.

[0026] Figure 11 Various examples of DL transmission with a preamble, signaling field, and data payload are illustrated.

[0027] Figure 12 An example of a preamble design for a carrier transmitted by a carrier transmitter in the time domain for DL transmission according to embodiments herein is illustrated.

[0028] Figure 13 An example of a preamble design in the frequency domain for DL transmission according to embodiments herein is illustrated.

[0029] Figure 14 A method of a base station according to an embodiment of this document is illustrated.

[0030] Figure 15 A method of environmental IoT tagging according to embodiments of this document is illustrated.

[0031] Figure 16 A method of a base station according to an embodiment of this document is illustrated.

[0032] Figure 17 A method of a base station according to an embodiment of this document is illustrated.

[0033] Figure 18 A method of environmental IoT tagging according to embodiments of this document is illustrated.

[0034] Figure 19 An exemplary architecture of a wireless communication system according to embodiments disclosed herein is shown.

[0035] Figure 20 A system for performing signaling between a wireless device and a network device according to embodiments disclosed herein is shown. DETAILED DESCRIPTION

[0036] Various embodiments are described with respect to a UE. However, reference to a UE is provided for illustrative purposes only. The example embodiments may be used with any electronic component that can establish a connection with a network and is configured with hardware, software, and / or firmware for exchanging information and data with the network. Therefore, as described herein, a UE is used to represent any suitable electronic component.

[0037] In some wireless communication systems, it may be beneficial to study a coordinated air interface design with minimized differences (where necessary) for the ambient Internet of Things (IoT) to enable various device categories. The first device category may include devices with a peak power consumption of approximately 1 μW, energy storage, an initial sampling frequency offset (SFO) of at most 10^X parts per million (ppm), and neither downlink (DL) nor uplink (UL) amplification in the device. For the first category of devices, the device's UL transmissions are backscattered on an externally provided carrier. The second device category may include devices with a peak power consumption of approximately less than or equal to a few hundred μW, energy storage, an initial SFO of at most 10^X ppm, and both DL and UL amplification in the device. For the second category of devices, the device's UL transmissions may be generated internally by the device or backscattered on an externally provided carrier. Both categories of devices may have a maximum coverage distance of, for example, 10-50 meters when the device is indoors. Additionally, devices using topologies 1 and 2 (e.g., UEs acting as intermediate nodes under network control) may have no radio resource control (RRC) state, no mobility (i.e., at least no cell selection / reselection functionality), no hybrid automatic repeat request (HARQ), and / or no automatic repeat request (ARQ).

[0038] Furthermore, it may be beneficial to discuss various deployment scenarios for such devices. For example, a first deployment scenario with topology 1 may include a base station and coexistence characteristics (e.g., microcell, co-site). A second deployment scenario with topology 2 may include a UE as an intermediate node under network control, a base station, and coexistence characteristics (e.g., macrocell, co-site). The intermediate node may be located indoors.

[0039] In some wireless communication schemes, there may be FR1 licensed spectrum in frequency division duplex (FDD). Spectrum deployment may be in-band to NR, in guard bands to LTE / NR and / or in independent bands. Traffic types may include device originated - device terminated triggered (DO-DTT) and / or device terminated (DT) types, with a focus on rUC1 (e.g., indoor inventory) and rUC4 (e.g., indoor commands). In addition, it may be beneficial to investigate whether a coordinated air interface design can address device originated autonomous (DO-A) use cases and / or identify which portion(s) of the coordinated air interface design (as per point 'A' above) is insufficient for DO-A use cases. Transmissions from ambient IoT tags (including backscatter when used) may occur at least in the UL spectrum.

[0040] Additionally, for ambient IoT DL and UL transmissions, it may be helpful to discuss frame structure, synchronization and timing, random access, parameter sets, bandwidth and multiple access, waveforms and modulation, channel coding, downlink channel / signal aspects, uplink channel / signal aspects, and / or scheduling and timing relationships. Furthermore, it may be helpful to discuss the characteristics of the carrier waveform of the carrier externally provided to the ambient IoT tag, including interference handling at the ambient IoT UL receiver and at the base station. Note that for Topology 2, the physical layer design may not differ from the physical layer design for Topology 1.

[0041] In some wireless communication systems, to achieve lower cost and lower power receivers, waveforms using amplitude modulation, such as on-off keying (OOK), have been widely used in radio frequency identifier (RFID) designs, 802.11 low power wake-up radios, and have been selected as candidate waveforms for low power wake-up signal (WUS) designs.

[0042] Carrier design and reuse process of IoT tags in different environments

[0043] Figure 1 Examples of carrier transmission and backscatter are illustrated.

[0044] In some wireless communication systems, some environmental IoT tags may operate based on an externally provided carrier.

[0045] In some examples, the base station 102 may transmit a carrier wave to the environmental IoT tag 104 , and the environmental IoT tag 104 may backscatter the carrier wave back to the base station 102 .

[0046] In some other examples, the UE 106 (or any other dedicated auxiliary device) may transmit a carrier wave to the ambient IoT tag 104 (a low category device), and the ambient IoT tag 104 may backscatter the carrier wave to the base station 102 .

[0047] Based on these examples, it should be understood that in some instances, the base station 102 and the UE 106 can provide a carrier wave to the ambient IoT tag 104. Furthermore, it should be noted that while the embodiments herein utilize a base station as a carrier wave transmitter and / or backscatter receiver in various scenarios (e.g., as described with respect to the base station 102), it should be understood that a base station can encompass a reader device or any other device controlled by a network to perform similar functions as a base station as described herein.

[0048] The ambient IoT tag 104 can receive a carrier wave from the base station 102 and / or the UE 106 and backscatter the carrier wave to the base station 102 using the backscatter transmitter 108. For example, the antenna 114 of the backscatter transmitter 108 can receive an incident RF signal 110 (e.g., a carrier wave) from the base station 102 and / or the UE 106. The antenna 114 of the backscatter transmitter 108 passes the incident RF signal 110 to the circuit 116 of the backscatter transmitter 108. The circuit 116 generates a modulated backscatter signal 112 from the incident RF signal 110. As shown, the circuit 116 may include, among other things, a channel coding and modulation block 118 for such purposes. The backscatter transmitter 108 can then output the modulated backscatter signal 112 (e.g., a backscatter carrier wave) to the base station 102.

[0049] It should be understood that Figure 1 While the form factor / capability category of the ambient IoT tag 104 is strictly illustrated, devices of more complex form factors / capability categories may function as ambient IoT tags as discussed herein. For example, in some cases, the ambient IoT tag may be a relatively complex device having a backscatter transmitter and / or otherwise configured to function as an ambient IoT tag within a system.

[0050] As already shown, the ambient IoT tag 104 represents a class of ambient IoT tags that use backscattering of a provided carrier wave. Other classes of ambient IoT tags are also discussed herein, including classes of ambient IoT tags that do not use backscattering but instead generate a carrier wave for their transmissions internally.

[0051] Figure 2 An example of multiple access between a base station and multiple environmental IoT tags according to the embodiments of this document is illustrated.

[0052] In some embodiments, the base station can read multiple ambient IoT tags simultaneously. In some cases, the base station can transmit carrier waves to various IoT tags. For example, the base station 204 can transmit carrier waves to the first ambient IoT tag 202 and / or the second ambient IoT tag 206 and receive backscattered waves from the first ambient IoT tag 202 and the second ambient IoT tag 206.

[0053] Figure 3 An example of multiple access as between a base station and a plurality of environmental IoT tags according to embodiments herein is illustrated, wherein carriers are provided to the environmental IoT tags by various UEs.

[0054] In some cases, devices other than the base station (such as UEs or dedicated auxiliary devices) can transmit carrier waves to various IoT tags in combination with the base station or independently of the base station. For example, the first UE 304 can transmit carrier waves to the first and second environmental IoT tags 310 and 312. The second UE 306 can transmit carrier waves to the third environmental IoT tag 314. The third UE 308 can transmit carrier waves to the fourth and fifth environmental IoT tags 316 and 318. The various environmental IoT tags (e.g., the first, second, third, and fourth environmental IoT tags 310 and 312) can backscatter carrier waves to the base station 302.

[0055] Details of the implementation regarding when the base station transmits a carrier wave to the ambient IoT tags are now discussed.

[0056] Figure 4 An example process for generating backscatter of a carrier wave at an ambient IoT tag according to embodiments herein is illustrated, where the carrier wave is received from a base station.

[0057] In some embodiments, a trigger packet payload, such as a DL trigger packet 418, may indicate a resource pool 420 for sending sensor / tag information. An ambient IoT tag receiving the DL trigger packet 418 may attempt to use one or more of the UL resources 422 of the resource pool 420 for use in feedback using backscatter as described herein.

[0058] In some examples, in addition to indicating the resource pool 420, the DL trigger packet 418 may also identify one or more ambient IoT tags to which feedback is to be provided. The ambient IoT tags polled by the base station may then attempt to randomly select a resource from the indicated resource pool for use in providing feedback using backscatter as described herein. For example, in the time domain, a resource from the resource pool may be randomly selected by the ambient IoT tag based on the trigger packet payload to generate backscatter from the carrier.

[0059] In some cases, when the resource pool contains only one resource and only one ambient IoT tag is requested for transmission, then the ambient IoT tag will transmit on the indicated resource.

[0060] In some cases, the DL trigger packet may indicate a resource pool and one or more ambient IoT tags to be fed back, such that there is a 1:1 mapping between the resources in the resource pool and the IoT tags. In such cases, each IoT tag uses the resources of the resource pool according to the 1:1 mapping.

[0061] The process for generating backscatter carrier waves begins with the base station 402 triggering 408 ambient IoT tag transmissions by transmitting a trigger packet (e.g., DL trigger packet 418) identifying an ambient IoT resource pool to a first ambient IoT tag 404 and a second ambient IoT tag 406. The base station 402 then transmits 410 carrier waves in the resource pool 420. The first ambient IoT tag 404 generates backscatter 412 of carrier waves that are transmitted back to the base station 402 using resources (e.g., randomly selected resources or indicated resources) from the identified resource pool. The second ambient IoT tag 406 also generates backscatter 416 of carrier waves that are transmitted back to the base station 402 using resources (e.g., randomly selected resources or indicated resources) from the identified resource pool.

[0062] Figure 5 An example process of selecting UL resources from a resource pool and for simultaneous use by generating backscatter of a carrier at a lower category ambient IoT tag and a higher category ambient IoT tag performing self-powered transmission according to embodiments herein is illustrated.

[0063] In the case where an ambient IoT tag selects resources from the ambient IoT resource pool, the corresponding DL triggered transmission can begin with a time synchronization preamble, which enables the ambient IoT tag to perform symbol timing acquisition and sampling time acquisition. The UL transmission performed by the ambient IoT tag can then follow the timing of the DL trigger transmitted by the base station.

[0064] The embodiments herein may involve two categories of ambient IoT tags: lower category ambient IoT tags may perform backscattering of an external carrier to transmit data, while higher category ambient IoT tags may transmit signals without receiving / using an external carrier in this manner.

[0065] In some examples, a separate resource pool for each category of ambient IoT tags may be used for UL resource selection. For example, a lower category ambient IoT tag may select one or more of the UL resources 528 in the resource pool 534 for lower category ambient IoT tags to perform backscattering, while a higher category ambient IoT tag may select one or more of the UL resources 530 from the resource pool 532 for higher category ambient IoT tags to perform its transmission.

[0066] In the first case 540 , the resource pool 532 for lower-class ambient IoT tags and the resource pool 534 for higher-class ambient IoT tags are separated in the time domain. Therefore, carriers are transmitted only at the time of the resource pool 532 for lower-class ambient IoT tags.

[0067] In a second scenario 542, the resource pool 532 for lower-class ambient IoT tags and the resource pool 534 for higher-class ambient IoT tags overlap in the time domain, as shown. In some such instances, the carrier used for backscatter by the lower-class ambient IoT tags is transmitted using a single-tone waveform corresponding to the frequency of the resource pool 532 for lower-class ambient IoT tags. The configuration information for the resource pool 534 for higher-class ambient IoT tags, as used by higher-class ambient IoT tags, may include both time-domain resource information for the resource pool 534 for higher-class ambient IoT tags and candidate frequency-domain information indicating one or more frequency tones that the higher-class ambient IoT tags can use for their transmissions in the resource pool (and which are different from the frequency tones used by the carrier used for lower-class ambient IoT tags in the resource pool 532 for lower-class ambient IoT tags). The higher-class ambient IoT tags use the indicated frequency tones for their transmissions, resulting in these transmissions being distinguishable from the backscattered signals of the lower-class ambient IoT tags on a frequency basis.

[0068] In some other instances, the carrier used for backscatter by the lower category environmental IoT tags is transmitted using a multi-tone waveform in which the frequency domain sequence is selected by the base station. The configuration information of the higher category environmental IoT tag resource pool used by the higher category environmental IoT tags may include the time domain resource information of the higher category environmental IoT tag resource pool plus the candidate frequency domain sequence. However, in such instances, one or more sequences that the higher category environmental IoT tags can use for their transmissions in the resource pool may be selected by the base station (and are different / non-overlapping sequences from the sequences used for the carrier used for the lower category environmental IoT tags in the lower category environmental IoT tag resource pool). The higher category environmental IoT tags use the selected sequences (as selected by the base station) for their transmissions, with the result that these transmissions are distinguishable from the backscatter signals of the lower category environmental IoT tags on a frequency basis.

[0069] The example process for generating a backscattered carrier wave at a lower-class ambient IoT tag and transmitting a signal at a higher-class ambient IoT tag begins with the base station 502 sending 512 a DL trigger packet 526 to the ambient IoT tag. The base station 502 then transmits 514 a carrier wave from a resource pool 532 for lower-class ambient IoT tags. Thus, a first lower-class ambient IoT tag 504 uses resources (e.g., randomly selected resources or indicated resources) from the resource pool 532 for lower-class ambient IoT tags to generate a backscattered carrier wave 516 for transmission back to the base station 502. Additionally, a second lower-class ambient IoT tag 506 uses (e.g., using randomly selected resources) from the resource pool 532 for lower-class ambient IoT tags to generate a backscattered carrier wave 520 for transmission back to the base station 502.

[0070] Furthermore, the first higher-class ambient IoT tag 508 transmits 522 data to the base station 502 using resources (e.g., randomly selected resources or indicated resources) of the resource pool 534 for higher-class ambient IoT tags, and the second higher-class ambient IoT tag 510 transmits 524 data to the base station 502 using resources (e.g., randomly selected resources or indicated resources) of the resource pool 534 for higher-class ambient IoT tags. Note that the first higher-class ambient IoT tag 508 and the second higher-class ambient IoT tag 510 do not need to receive a carrier wave from the base station 502 because the higher classes independently generate their transmissions (rather than relying on backscatter).

[0071] Details of an implementation where a UE or another dedicated auxiliary device transmits a carrier wave for use by various ambient IoT tags are now discussed.

[0072] In some embodiments, different ambient IoT tags may backscatter carriers from different UEs and / or auxiliary devices. For such cases, each carrier may be configured to carry a signature that ultimately enables multiple access at the base station, as will be described.

[0073] In some cases, the backscatter carriers received from ambient IoT tags can be frequency division multiplexed (FDM) together. In one such example, a single carrier of the same frequency tone can be used by each secondary device transmitting that carrier. However, each secondary device can be instructed to use a separate subcarrier within that frequency tone to perform transmissions. Thus, since different ambient IoT tags backscatter various carriers from various UEs / secondary devices, and from the base station's perspective, the received backscatter for any given time resource is FDMed together.

[0074] The base station may schedule a secondary device or UE to transmit a carrier on an UL frequency of an FDD band. In some examples, the scheduling may be based on UE-specific downlink control information (DCI), where the base station may send a first DCI to schedule a first UE to transmit a carrier on a first subcarrier of a carrier configuration. A second DCI may be used to schedule a second UE to transmit a carrier on a second subcarrier of the carrier configuration, without any constraints on when any secondary device may be scheduled to transmit a carrier, such that the scheduling may overlap in time.

[0075] In some other examples, group DCI may be used. For example, a base station may send one DCI that schedules both a first UE and a second UE to transmit a carrier at different subcarriers of a carrier configuration, without any constraints on when any secondary device may be scheduled to transmit the carrier, such that the scheduling may overlap in time.

[0076] FDMization occurs because the base station uses DCI (e.g., UE-specific or group) to instruct each UE to use different subcarriers within the overall carrier configuration. In this way, any jointly received backscatter is received on different subcarriers in an FDM manner. Thus, the base station is able to decode such signals from each other.

[0077] In some other cases, the backscattered carriers received from ambient IoT tags can be code division multiplexed (CDM) together. For example, each UE may transmit a different sequence in the frequency domain. Then, since the various ambient IoT tags use the same time resources to backscatter different carriers for various different UEs, the signals received at the base station are CDMed accordingly, allowing the base station to decode such signals (due to sequence orthogonality).

[0078] To facilitate this CDM, the base station can schedule each secondary device to transmit a carrier on the UL frequency of the FDD band. In some instances, UE-specific DCI for each of the secondary devices can be used for such scheduling. For example, the base station can send a first DCI scheduling a first UE to transmit a carrier using a first sequence and a second DCI scheduling a second UE to transmit a carrier using a second sequence, without any constraints on when any secondary device can be scheduled to transmit a carrier, so that the scheduling can overlap in time.

[0079] In some other examples, group DCI may be used. For example, the base station may send one DCI that schedules each of the first UE and the second UE to transmit a carrier, but with different sequences, without constraints on when any secondary device may be scheduled to transmit a carrier, so that the scheduling may overlap in time.

[0080] CDM occurs because the base station uses DCI (e.g., UE-specific or group) to instruct each UE to use a different sequence in the frequency domain. Thus, due to the use of different sequences, any jointly received backscatter is received in a CDM manner, thus enabling the base stations to decode such signals from each other.

[0081] Figure 6 An example process for generating a backscatter carrier according to embodiments herein is illustrated, where the carrier is received from a UE or a secondary device.

[0082] The process begins with the base station 602 triggering 612 an ambient IoT tag transmission as discussed herein (e.g., using a DL trigger packet). The base station 602 then transmits 614 an UL schedule to a first UE 604 (e.g., using a UE-specific DCI or group DCI for the first UE 604, as discussed herein), and transmits 616 an UL schedule to a second UE 608 (e.g., using a UE-specific DCI or group DCI for the second UE 608, as discussed herein). Based on its reception of the UL schedule, the first UE 604 transmits 618 a first carrier to the first ambient IoT tag 606. Additionally, based on its reception of the UL schedule, the second UE 608 transmits 620 a second carrier to the second ambient IoT tag 610.

[0083] As described above, in the case of FDM, the first UE 604 may use the first subcarrier for transmission of its first carrier, and the second UE 608 may use the second subcarrier for transmission of its second carrier. In addition, in the case of CDM, the first UE 604 may use the first sequence in the frequency domain for transmission of its first carrier, and the second UE 608 may use the second sequence in the frequency domain for transmission of its second carrier.

[0084] Thus, the first ambient IoT tag 606 generates backscatter 622 of a first carrier for transmission back to the base station 602 (e.g., using a randomly selected resource from the resource pool indicated in the DL trigger packet). In addition, the second ambient IoT tag 610 generates backscatter 624 of a second carrier for transmission back to the base station 602 (e.g., using a randomly selected resource from the resource pool indicated in the DL trigger packet).

[0085] It should be appreciated that if base station 602 receives backscatter simultaneously, it may utilize FDMization and / or CDMization (as appropriate) to interpret the jointly received backscatter.

[0086] In some embodiments, a combination of the scenarios discussed herein may be used, wherein the received backscatter may be used by both FDM and CDM, and further wherein a selection within the ambient IoT resource pool is used by the receiving ambient IoT tag. The base station may schedule the UE or auxiliary device to transmit a carrier on the UL frequency of the FDD band. In some instances, UE-specific DCI may be used. For example, the base station may send a first DCI to schedule a first UE or auxiliary device to transmit a carrier at a first subcarrier of a carrier configuration and / or using a specific CDM code, and may send a second DCI to schedule a second UE or auxiliary device to transmit a carrier at a second subcarrier of a carrier configuration and / or using another different specific CDM code. Such UE-specific DCI may schedule multiple time slots on the resource pool for selection by the ambient IoT tag.

[0087] In some other examples, group DCI may be used. For example, the base station may send one DCI that schedules each of the first UE or auxiliary device and the second UE or auxiliary device to transmit a carrier according to different subcarriers and / or different CDM codes of the carrier configuration. For example, the base station may send one DCI to schedule the first UE or auxiliary device and the second UE or auxiliary device to transmit the carrier at different subcarriers of the carrier configuration and / or using different CDM codes, without any constraints on when any auxiliary device may be scheduled to transmit the carrier, so that the scheduling may overlap in time.

[0088] Figure 7 An example process for generating backscatter that is both FDM and CDM according to embodiments herein is illustrated, and wherein an ambient IoT tag selects resources for performing backscatter from an ambient IoT resource library.

[0089] For example, the process for generating backscatter using both FDM and CDM begins with base station 702 triggering 710 an ambient IoT tag transmission using a DL trigger packet 720. Base station 702 transmits 712 an UL schedule (e.g., using UE-specific DCI or group DCI) to a first UE 704. Based on the UL schedule, first UE 704 transmits 714 a carrier to a first ambient IoT tag 706 and a second ambient IoT tag 708. The carrier may be transmitted in multiple time slots of a corresponding resource pool 724.

[0090] Thus, the first ambient IoT tag 706 generates backscatter 716 of a carrier wave for transmission to the base station 702, and the second ambient IoT tag 708 generates backscatter 718 of a carrier wave for transmission back to the base station 702. To accomplish this, the first ambient IoT tag 706 and the second ambient IoT tag 708 may each select a UL resource 722 (e.g., randomly or as indicated) from a resource pool 724 of UL resources 722 for transmission.

[0091] Thus, it is contemplated that backscatter can be performed / arrived at the base station in the same time resource. In such cases, the base station 702 can utilize efficient FDM and / or CDM of backscatter to differentiate the signals. Thus, it can be generally understood that the use of the resource pool 724 occurs based on potential separation in any one or more of the frequency domain, time domain, and / or code / sequence domain, as already described herein.

[0092] It should be noted that while the various examples herein only explicitly illustrate the use of lower-class ambient IoT tags using backscatter of a carrier wave, in such embodiments, it may be the case that higher-class ambient IoT tags (not shown) may also be active. It will generally be understood that, in the event that higher-class ambient IoT tags are also scheduled to perform transmissions in such instances, these transmissions may be configured to be orthogonal to any carrier wave (and any backscatter performed by any lower-class ambient IoT tags using that carrier wave) in at least one of the time domain, the frequency domain, and / or the code / sequence domain (e.g., by using a separate resource pool configuration that is orthogonal to the resource pool of the lower-class ambient IoT tags).

[0093] The embodiments of this document relate to multiple access schemes. In addition, the embodiments of this document relate to random access procedures. For example, from a physical layer perspective, at least when responses from multiple devices intended to be identified are expected, an access procedure based on ambient IoT contention initiated by the reader is used, for which at least slotted ALOHA-based access and FDMA are studied. The study of FDMA includes how to allocate frequency domain resources for Msg1 and how the device determines the frequency domain resource allocation. During this process, the response transmitted from the device to the reader is transmitted on the physical device to reader control channel (PDRCH). The reader-to-device (R2D) transmission that triggers random access determines X time domain resources for the device-to-reader (D2R) transmission of Msg1, where each D2R transmission for Msg1 occurs in one of the X time domain resources. It may be beneficial to study the value of X so that X=1 and X>1 and X>=1. The maximum value of X>1 should be set considering device implementation complexity, device power consumption, resource utilization efficiency at least affected by SFO, and inventory delay. Additionally, it may be beneficial to study the size of resource allocations in the time domain, the determination of X time domain resources by a device, and addressing timing errors of adjacent time domain resources due to residual SFO of a device.

[0094] It may be beneficial to examine various examples of Msg2 transmissions in response to multiple Msg1 transmissions initiated by an R2D transmission that triggers random access. In one example, the physical reader-to-device control channel (PRDCH) used for Msg2 transmission corresponds to an ambient IoT Msg1 received from one device. In a second example, the PRDCH used for Msg2 transmission corresponds to multiple ambient IoT Msg1s received from different devices.

[0095] For Msg3s from multiple devices in response to a given set of one or more Msg2 transmissions during the access procedure, FDMA and / or TDMA for D2R transmissions can be studied, including how to allocate frequency and time domain resources for Msg3s. In addition, it may be beneficial to study the start time and duration of Msg2 monitoring for Msg2 reception.

[0096] Furthermore, embodiments herein relate to various carriers. For example, various carrier waveform characteristics that can control carrier nodes / auxiliary devices can be identified, such as when to transmit or not transmit a carrier, transmit power, and frequency resources, such as the frequency location of a waveform (e.g., a first waveform or a second waveform). Further investigation of other carrier waveform characteristics that may be required to control carrier nodes / auxiliary devices (if any) is possible.

[0097] Interference suppression and channel estimation methods for IoT transmission in backscatter environments

[0098] Figure 8A A first example of lower category IoT tag usage is illustrated where interference may affect signaling.

[0099] As discussed herein, for at least some lower-class ambient IoT tags, a carrier wave is provided externally to enable backscatter operation. The carrier wave can be transmitted by the base station to the lower-class ambient IoT tags. This results in full-duplex reception. The base station may need to eliminate the carrier wave (e.g., by implementation) because the base station acts as both the source of the carrier wave and the destination of the backscattered carrier wave.

[0100] For example, the base station 802 transmits 806 a carrier wave to the ambient IoT tag 804. Consequently, the ambient IoT tag 804 backscatters 808 the transmitted carrier wave back to the base station 802. As such, the base station 802 may need to cancel the carrier wave because the base station 802 acts as both a source of the carrier wave and a destination of the backscattered carrier wave (e.g., backscattered by the ambient IoT tag 804).

[0101] Figure 8B A second example of lower category IoT tag usage is illustrated where interference may affect signaling.

[0102] In some cases, the base station 810 acts as a reader of the modulated carrier wave (backscatter) of the ambient IoT tag 812 from a carrier wave originally transmitted by an auxiliary device 814 (such as the auxiliary devices discussed herein).

[0103] This article discusses the various channels that exist for such situations. Figure 8B As shown, the channel h_1(t) 820 used by the modulated carrier operates between the auxiliary device 814 and the environmental IoT tag 812. Furthermore, the channel h_2(t) 816 used by the carrier operates between the auxiliary device 814 and the base station 810. Finally, the channel h_3(t) 818 used by the carrier operates between the environmental IoT tag 812 and the base station 810.

[0104] In this case, base station 810 receives an unmodulated carrier from auxiliary device 814 on channel h_2(t) 816 and a modulated carrier from ambient IoT tag 812 on channel h_3(t) 818. Generally speaking, if the carrier transmitted by auxiliary device 814 is signal c(t) 822 and the corresponding backscatter from ambient IoT tag 812 is signal s(t) 824, then, according to the system model, the received signal y(t) 826 at the base station includes both signal c(t) 822 and signal s(t) 824. Therefore, signal c(t) 822 originating from auxiliary device 814, as received on channel h_2(t) 816, represents interference with signal s(t) 824 received at the base station from ambient IoT tag 812. Note also that, according to this model, signaling along channel h_1(t) 820 does not cause such interference.

[0105] In summary, an interference condition occurs when the base station 810 jointly receives both the carrier from the auxiliary device 814 on channel h_2(t) 816 (signal c(t) 822) and the backscatter of the same carrier from the ambient IoT tag 812 on channel h_3(t) 818 (signal s(t) 824).

[0106] Furthermore, note that in many cases, the interfering component (signal c(t) 822 on channel h_2(t) 816) may be stronger than the desired signal (signal s(t) 824 on channel h_3(t) 818) due to various factors. A first factor may be, for example, a "double" path loss associated with the nature of signal s(t) 824. Since signal s(t) 824 is a backscatter of signal c(t) 822 along channel h_1(t) 820, signal s(t) 824 perceived at base station 810 ultimately experiences path loss along both channel h_1(t) 820 and channel h_3(t) 818. This contrasts with signal c(t) 822 received at base station 802, which experiences only a "single" path loss along channel h_2(t) 816.

[0107] A second factor may be that the reflection / backscattering efficiency of the ambient IoT tag 812 is not perfect (eg, where 1 represents perfectly efficient reflection / backscattering, and real-world results are typically between (0, 1)).

[0108] The embodiments herein describe details of handling interference caused by carrier transmissions. Such embodiments are applicable to situations where multiple auxiliary devices transmit carriers to one or more ambient IoT tags.

[0109] The embodiments herein describe designs for preamble transmission (e.g., time-domain orthogonal code designs) that facilitate signal estimation for interference reduction purposes. Figure 8B Interference can be determined using the mathematical framework discussed in

[15] . Based on the preamble design, the base station / reader can then estimate the channel h2(t), as will be described. Therefore, after determining the estimate of the channel h2(t), the base station can subtract the estimated interference from the total received signal according to y(t) - c(t) * h2(t).

[0110] Various transmission formats are proposed to facilitate interference estimation. A secondary device may transmit the same carrier over a period of time. This transmission may be triggered by base station / reader scheduling, as discussed herein. Depending on the situation, this transmission may be scheduled using dynamic scheduling or configured scheduling. An example of a time-domain sequence transmitted by a secondary device (or equivalent) may be [1 1 1 1…].

[0111] Turning to the corresponding backscatter generated by the ambient IoT tag, it can be understood that the first few symbols of the carrier wave will be considered as a preamble that the ambient IoT tag can modulate for the purpose of facilitating channel estimation for both interference and data demodulation purposes. More specifically, the ambient IoT tag can implement a time-domain orthogonal code along with / on the first few preamble symbols of the carrier wave as received from the auxiliary device.

[0112] In some embodiments, the environmental IoT tag modulates the preamble symbol of the carrier using OOK modulation. An example of a sequence format of preamble symbols that can be applied by the environmental IoT tag to the carrier in the OOK case is [1 0] (corresponding to the case where two symbols are used for the preamble). Another example of a sequence format of preamble symbols that can be applied by the environmental IoT tag to the carrier can be [1 1 0 0] (corresponding to the case where four symbols are used for the preamble).

[0113] In another example, if phase information is used, the sequence format applied by the ambient IoT tag to these first few symbols can be [1 -1] (2 symbol preamble) or [1 1 -1-1] (four symbol preamble), etc.

[0114] Figure 9 Examples of UL packet formats according to various preamble lengths according to embodiments of this document are illustrated.

[0115] As already discussed, UL transmissions as understood / received by the reader / base station may begin with UL packets corresponding to the carrier's preamble (e.g., the first few symbols are designed / reserved as preambles). The base station may accordingly understand that these UL packets are preambles that have been orthogonally modulated by the ambient IoT tags according to a fixed pattern.

[0116] Note that various lengths (e.g., number of symbols) may be used for the preamble, such as a 2-symbol preamble or a 4-symbol preamble. For example, the backscatter 904 of the carrier 902 may include a two-symbol preamble 908, which includes a first packet modulated at phase 1 and a second packet modulated at phase -1. The remainder of the UL packet format includes modulated data superimposed on the carrier 902 by the ambient IoT tag.

[0117] In another example, the backscatter 906 may include a four symbol preamble 910 including a first packet having a value of 1, a second packet having a value of 1, a third packet having a value of -1, and a fourth packet having a value of -1. The remainder of the UL packet format includes modulated data superimposed on the carrier 902 by the ambient IoT tag.

[0118] In cases similar to those being discussed, where phase-based modulation is used by the ambient IoT tag to modulate the carrier 902 corresponding to the preamble symbols, an estimate of the channel h_2(t) (the channel between the secondary device and the base station) can be generated by the base station by adding together the symbols of the preamble and then normalizing the result. Due to the orthogonal modulation performed on these symbols by the ambient IoT tag, this addition eliminates the signaling portion of these UL packets on these symbols that can be attributed to the channel h_3(t) (the channel between the ambient IoT tag and the base station / reader), leaving only the information corresponding to the channel h_2(t). Normalization accounts for the fact that multiple UL packets contribute to the unnormalized result, but h_2(t) needs to be estimated based on a single UL packet. Note that this process assumes that the various channels between the entities do not change during the duration of the preamble.

[0119] In such an example, the base station can determine an estimate of the channel h_2(t) (the channel between the base station / reader and the secondary device) by normalizing the result of the sum of the symbols of the preamble. For a two-symbol preamble, y(1) (the first symbol of the preamble) and y(2) (the second symbol of the preamble) can be added together and normalized. Thus, the estimate of the channel h_2 is equal to (y(1) + y(2)) / 2. For a four-symbol preamble, y((1) (the first symbol of the preamble), y(2) (the second symbol of the preamble), y(3) (the third symbol of the preamble), and y(4) (the fourth symbol of the preamble) can be added together and normalized. Thus, the estimate of the channel h_2 is equal to (y(1) + y(2) + y(3) + y(4)) / 4.

[0120] Figure 10 Examples of UL packet formats with varying preamble lengths using OOK transmission according to embodiments herein are illustrated.

[0121] In some cases, OOK transmission can be used. For example, to estimate the channel h_2(t) (the channel between the base station and the secondary device), the base station can measure the received signal of a known symbol where the ambient IoT tag does not perform any backscatter (such as the "0" value symbol discussed herein). Therefore, any signal read by the base station during the reception of such a "0" value symbol can be directly attributed to the channel h_2(t) (the channel between the base station and the secondary device). Note that this process assumes that the various channels between the entities do not change during the duration of the preamble.

[0122] In such an example, for backscatter 1004 with a two-symbol preamble 1008, the reader can estimate the channel h_2(t) (the channel between the base station and the secondary device) based on the value "0" symbol of backscatter 1004 of carrier 1002. That is, the channel estimate h_2(t) is equal to the second symbol (y(2)) of backscatter 1004.

[0123] For a backscatter 1006 with a four-symbol preamble 1010, the reader can estimate the channel h_2(t) (the channel between the base station and the secondary device) based on the "0" symbol of the backscatter 1006 of the carrier 1002. That is, the channel estimate h_2 is equal to the third symbol (y(3)) normalized by the fourth symbol (y(4)). Thus, the channel estimate can be expressed as h_2(t) = (y(3) + y(4)) / 2. The normalization accounts for the fact that multiple UL packets contribute to the non-normalized result, but it is necessary to estimate h_2(t) based on a single UL packet.

[0124] Note that unlike the preamble design for DL transmission (where a longer preamble may be introduced to provide time / sampling synchronization for the entire message exchange), the UL preamble in these cases may be primarily used for interference estimation and cancellation. The base station may also use coherent detection for information decoding.

[0125] In some embodiments, different arrangements for generating orthogonal sequences can be used. For example, in some cases, the carrier itself can be modulated with a fixed time-domain sequence (instead of all ones, the transmission pattern can take the form of [1-1-1...]). The ambient IoT tag can then perform backscattering on the preamble portion of the carrier so that the modulated waveform received at the reader is / remains orthogonal (such as, for the example carrier transmission pattern just provided, using a phase sequence of [1-1-1] for backscattering).

[0126] Embodiments herein may relate to a D2R timing acquisition signal. For example, a D2R timing acquisition signal (D-TAS) preceding each PDRCH may be included for at least timing acquisition, indicating the start of D2R transmission in the time domain, and potentially studied for SFO estimation, carrier frequency offset (CFO) estimation, channel estimation, and interference estimation. It may be beneficial to study the D-TAS structure using a preamble that takes into account binary signals. The preamble is not part of the PDRCH.

[0127] The embodiments herein relate to various characteristics of the carrier waveform. For example, the following cases 1-4, 2-3, and 2-4 provide detailed descriptions of various waveform characteristics, which may be beneficial for further study.

[0128] In cases 1-4, it can be:

[0129] No need for base stations to support full-duplex capability in the UL spectrum;

[0130] Spatial isolation is possible, thereby reducing the carrier interference power received at the base station side;

[0131] Cross-link interference handling of carriers can occur at the base station side;

[0132] An estimate of carrier interference may be useful for successful D2R reception at the base station; and

[0133] • Lower carrier transmission power may be assumed in the UL spectrum than in the DL spectrum.

[0134] In case 2-3, it can be:

[0135] No need for intermediate UEs to support full-duplex capability in the DL spectrum;

[0136] Spatial isolation is possible, thereby reducing the carrier interference power received at the middle UE side;

[0137] Cross-link interference handling of carriers can occur at the intermediate UE side;

[0138] • An estimate of carrier interference may be useful for successful D2R reception at the intermediate UE; and

[0139] • A higher carrier transmission power may be assumed in the DL spectrum than in the UL spectrum.

[0140] In cases 2-4, it can be:

[0141] No need for intermediate UEs to support full-duplex capability in the UL spectrum;

[0142] Spatial isolation is possible, thereby reducing the carrier interference power received at the middle UE side;

[0143] Cross-link interference handling of carriers can occur at the intermediate UE side;

[0144] • Successful D2R reception at the intermediate UE may require an estimate of the carrier interference; and

[0145] • Lower carrier transmission power may be assumed in the UL spectrum than in the DL spectrum.

[0146] Downlink synchronization preamble design and transmission format for ambient IoT transmission using OOK waveform

[0147] The embodiments herein take into account various parameters for transmission sampling. For example, the initial sampling offset may be large (e.g., 10^5 ppm sampling offset). In addition, the embodiments herein may have no RRC state requirements. Therefore, it is not expected that the UE stays in RRC_CONNECTED mode (e.g., connected) between transmissions. For example, it is not expected that the UE maintains timing / frequency synchronization as it does in RRC_CONNECTED mode.

[0148] The embodiments herein introduce a DL preamble design that achieves synchronization based on physical layer protocol data unit (PPDU) transmissions. In some cases, the frame / slot structure for an ambient IoT design with an OOK waveform may include a PPDU transmission format, a preamble, a signaling field indicating the transmission length, and / or a PPDU payload. The preamble design may include fast automatic gain control (AGC) convergence, symbol timing synchronization, and may carry information for both high- and low-category devices.

[0149] Figure 11 Various examples of DL transmission with a preamble, signaling field, and data payload are illustrated.

[0150] Embodiments herein may relate to amplitude modulation for low-power, low-cost receivers using OOK. An orthogonal frequency division multiplexing (OFDM) waveform may be used to generate an OOK signal, and an OOK symbol may be equivalent to one OFDM symbol. Based on the OFDM subcarrier spacing, the OOK symbol length may be shorter or longer. In some instances, the preamble design may use a time domain sequence (e.g., a sequence modulated per OOK symbol in the time domain). In addition, to generate the OOK symbol, a sequence in the frequency domain per OFDM symbol may be used to enhance the performance of higher-class environmental IoT tags.

[0151] In some embodiments, a DL transmission may include a preamble, a signaling field, and a data payload. In a first example 1102, a DL transmission may include a preamble 1110, a signaling field 1112, and three data payload 1114 time slots. In a second example 1104, a DL transmission may include a first time slot with a preamble and signaling field 1116 and three data payload 1114 time slots. In a third example 1106, a DL transmission may include a preamble and signaling field 1116 across two time slots and three data payload 1114 time slots. In a fourth example 1108, a DL transmission may include a preamble 1110 across two time slots and three data payload 1114 time slots. Note that the fourth example 1108 does not include a signaling field. Thus, it can be used in situations where a signaling field is not required, such as at the end of a packet detection process.

[0152] In some cases, the preamble 1110 may represent a time domain sequence modulated on each OOK symbol (e.g., an OFDM symbol if an OFDM waveform is used as an in-band transmission). The signaling field 1112 indicates the length of the data in bytes. If a different modulation is used, the signaling field 1112 may also indicate the modulation format of the data (e.g., using phase over amplitude for higher data rate transmission). In some instances, if only a limited amount of information is required (such as one or two bits), this information may be carried by the sequence itself (e.g., by a DL transmission).

[0153] Figure 12 An example of a preamble design for a carrier transmitted by a carrier transmitter in the time domain for DL transmission according to embodiments herein is illustrated.

[0154] In some embodiments, a preamble sequence design can be introduced in the time domain. For example, to achieve accurate time synchronization, false detection of the preamble should be avoided, and thus the autocorrelation peak / second peak of the cross-correlation can be maximized. To achieve efficient AGC operation, the sequence can avoid long runs of zeros and ones. In addition, to achieve faster AGC operation, the beginning of the sequence can use repetition / patterning. In some cases, the sequence 1202 has a similar number of zeros and ones.

[0155] For example, the plurality of sequences 1202 may include fourteen 1204 symbols, and the sequence 1202 may take the form of 1 0 1 0 0 0 11 0 1 1 0 1 0. For cross-correlation, the local reference is 2s-1.

[0156] In some cases, the length of the sequence can be multiple slots, or a combination of multiple slots and partial slots. For example, two slots can be used, for a total of 28 symbols. As another example, two slots and a partial slot of four symbols can be used, for a total of 32 symbols. In such an example, the remaining ten symbols of the third slot can be followed by a signaling field as discussed herein.

[0157] Figure 13 An example of a preamble design in the frequency domain for DL transmission according to embodiments herein is illustrated.

[0158] In some implementations, a frequency-domain preamble sequence design can be used. Depending on the ambient IoT system bandwidth, a frequency-domain sequence can be defined for OFDM symbol generation. For example, within a resource block 1304, symbol 1302 may have the sequence 1,-1,1,1,-1,-1,-1,-1,-1,-1,1. Furthermore, high-class UEs can use frequency-domain sequence detection to improve per-symbol detection. Either an M sequence or a Zadoff-Chu (ZC) sequence can be used as the frequency-domain sequence.

[0159] Now, we will discuss an embodiment of the signaling field design as used in DL transmissions. The signaling field can be a full slot or a portion of a slot (e.g., a half slot) to indicate, for example, the payload size and / or the modulation scheme (if multiple are supported for different data rates). The signaling field can use basic OOK (e.g., amplitude modulation). In addition, both high-class IoT tags and low-class IoT tags can decode the signaling field.

[0160] Now, we will discuss embodiments of data payload designs as used in DL transmissions. Data transmission (e.g., data payload) follows the signaling field. The data payload may use the modulation and length fields indicated by the signaling field. Furthermore, transmissions may continue for multiple time slots until all time slots have been transmitted (e.g., the transmission is complete).

[0161] Embodiments herein may contemplate an R2D Timing Acquisition Signal (R-TAS) immediately preceding the transmission of a PRDCH. The R-TAS is included for at least timing acquisition and indicating the start of an R2D transmission in the time domain. An R-TAS structure using a preamble may be explored, wherein a start indicator portion provides the start of an R2D transmission and immediately precedes a clock acquisition portion that is used to determine the OOK chip duration for subsequent PRDCH transmissions. The preamble is not part of the PRDCH. In T D2R_min The R-TAS start indicator part is not included in the transmission, and an ON / OFF pattern, i.e., high / low voltage transmission, is applied. Further investigation of the case of the start indicator part may be beneficial. In some cases, ON-OFF transmissions are considered based on energy / edge detection, and various alternatives have been explored, including single ON-OFF transmissions, i.e., a high voltage transmission followed by a low voltage transmission, where the ON and OFF phases can have the same or different durations, or multiple ON-OFF transmissions, where different ONs and different OFFs can have the same or different durations and different phases can have the same or different durations. In some other cases, designs based on ON-OFF sequences are considered, which include a predefined sequence for detecting the start indicator part based on digital correlation. For both cases, it is observed that a fixed duration for the start indicator part can be considered, regardless of the value of M used for the PRDCH transmission. Furthermore, for both cases, it may be beneficial for the start indicator part to be at least distinguishable from the other parts of the R2D transmission.

[0162] The embodiments herein may contemplate clock acquisition. For example, the clock acquisition portion is based on OOK without line coding and includes rising / falling edges, including at least two rising edges or at least two falling edges for the device to determine the duration of the OOK chip. Various options for designing the clock acquisition portion may be further explored. In some options, the duration of the clock acquisition portion is variable for different M values, i.e., the duration becomes shorter as the M value increases. In some other options, the duration of the clock acquisition portion is constant for different M values based on repetition, i.e., the repetition factor increases with the M value to keep the duration constant. Whether / what restrictions are there on the M value of the clock acquisition portion may be further discussed.

[0163] Embodiments herein may contemplate a PRDCH channel. For example, for R2D, the only physical channel is the PRDCH, which carries any higher layer payload (including system information, if defined) and Layer 1 (L1) R2D control information (if defined). It may be beneficial to explore various design scenarios for the PRDCH. In some cases, if there is no L1 R2D control information carried by the PRDCH, a PRDCH transmission with only R2D is considered. Note that in this case, the R2D control information (if any) may be carried by higher layer signaling. In some other cases, if the PRDCH supports and carries any L1 R2D control information, a cyclic redundancy check (CRC) is used for attachment (if a non-zero length CRC is present). In some such cases, a joint CRC is attached to the L1 R2D control information and the R2D data. In some other such cases, separate CRCs are attached to the L1 R2D control information and the R2D data, respectively.

[0164] Figure 14 A method 1400 of a base station according to embodiments herein is illustrated. The illustrated method 1400 includes sending 1402 a trigger message identifying a first set of ambient IoT resources to a first ambient IoT tag. The method 1400 also includes receiving 1404 first backscatter derived from a carrier by the first ambient IoT tag in a first resource of the first set of ambient IoT resources. The method 1400 also includes decoding 1406 first data of the first ambient IoT tag from the first backscatter.

[0165] In some embodiments, method 1400 further includes transmitting the carrier in the first environment IoT resource set.

[0166] In some embodiments, method 1400 further includes sending an instruction to the secondary device to transmit the carrier in the first environment IoT resource set.

[0167] In some embodiments of the method 1400 , the trigger message includes a first indication that the first environmental IoT tag is to generate a first backscatter.

[0168] In some embodiments of method 1400, a trigger message is sent to a second ambient IoT tag, and the method further includes receiving a second backscatter signal derived from a carrier wave by the second ambient IoT tag in a second resource of the first set of ambient IoT resources, and decoding second data of the second ambient IoT tag from the second backscatter signal. In some such embodiments, the trigger message further includes a second indication that the second ambient IoT tag is to generate the second backscatter signal.

[0169] In some embodiments of method 1400, the trigger message further identifies a second set of ambient IoT resources in which no carrier is transmitted; and the method further includes receiving a transmission in a second resource of the second set of ambient IoT resources from the second ambient IoT tag. In some such embodiments, the first set of ambient IoT resources and the second set of ambient IoT resources are separated in the time domain. In some other such embodiments, the first set of ambient IoT resources and the second set of ambient IoT resources are overlapping in the time domain and separated in the frequency domain. In some such embodiments, the first set of ambient IoT resources is located on a frequency tone used by the carrier. In some other such embodiments, the first set of ambient IoT resources is located on a frequency tone sequence used by the carrier.

[0170] In some embodiments of method 1400, the trigger message includes a synchronization preamble for acquiring a frequency and timing corresponding to a carrier.

[0171] Figure 15 A method 1500 for an ambient IoT tag according to embodiments herein is illustrated. The illustrated method 1500 includes receiving 1502 a trigger message from a first base station identifying a first set of ambient IoT resources. The method 1500 also includes receiving 1504 a carrier wave in the first set of ambient IoT resources. The method 1500 also includes generating 1506 a first backscatter signal in a first resource of the first set of ambient IoT resources using the carrier wave.

[0172] In some implementations of method 1500, the carrier is received from a base station.

[0173] In some embodiments of method 1500, the carrier wave is received from a secondary device.

[0174] In some embodiments of the method 1500 , the trigger message includes a first indication that the first environmental IoT tag is to generate a first backscatter.

[0175] In some embodiments, the method 1500 further includes randomly selecting a first resource of the first ambient IoT resource set from one or more resources of the first ambient IoT resource set.

[0176] In some embodiments of the method 1500 , the trigger message further includes a second indication that the second environmental IoT tag is to generate a second backscatter.

[0177] In some embodiments of method 1500, the trigger message further identifies a second set of ambient IoT resources in which no carrier is transmitted. In some such embodiments, the first set of ambient IoT resources and the second set of ambient IoT resources are separated in the time domain. In some other such embodiments, the first set of ambient IoT resources and the second set of ambient IoT resources are overlapping in the time domain and separated in the frequency domain. In some such embodiments, the first set of ambient IoT resources is located on a frequency tone, and wherein the carrier is received on the frequency tone. In some other such embodiments, the first set of ambient IoT resources is located on a frequency tone sequence, and wherein the carrier is received on the frequency tone sequence.

[0178] In some embodiments of method 1500, the trigger message includes a synchronization preamble for acquiring a frequency and timing corresponding to a carrier.

[0179] Figure 16 A method 1600 for a base station according to an embodiment of the present invention is illustrated. The illustrated method 1600 includes sending 1602 a first DCI to a first UE instructing the first UE to transmit a first carrier on a first subcarrier during a time slot. The method 1600 also includes sending 1604 a second DCI to a second UE instructing the second UE to transmit a second carrier on a second subcarrier during the time slot. The method 1600 also includes receiving 1606 during the time slot: a first composite transmission on the first subcarrier, the first composite transmission including the first carrier as transmitted by the first UE and a first backscatter generated by a first ambient IoT tag from the first carrier; and a second composite transmission on the second subcarrier, the second composite transmission including the second carrier as transmitted by the second UE and a second backscatter generated by a second ambient IoT tag from the second carrier. The method 1600 also includes decoding 1608 first data of the first ambient IoT tag from the first backscatter. The method 1600 also includes decoding 1610 second data of the second ambient IoT tag from the second backscatter.

[0180] In some embodiments, method 1600 further includes isolating the first backscatter from the first composite transmission by estimating a channel between the first UE and the base station, determining a portion of the first composite transmission associated with the first carrier as transmitted by the first UE based on the estimate of the channel between the first UE and the base station, and subtracting the portion of the first composite transmission associated with the first carrier as transmitted by the first UE from the first composite transmission. In some such embodiments, the base station estimates the channel between the first UE and the base station by averaging a sum of a number of symbols of the first composite transmission corresponding to preambles used in the first backscatter.

[0181] In some other such embodiments, the number of symbols includes a first time symbol of the first composite transmission and a second time symbol of the first composite transmission. In some such embodiments, the number of symbols also includes a third time symbol of the first composite transmission and a fourth time symbol of the first composite transmission.

[0182] In yet other such embodiments, the base station estimates the channel between the first UE and the base station by taking a measurement of a preconfigured symbol of the first composite transmission as a representation of the channel between the first UE and the base station. In some such embodiments, the preconfigured symbol comprises a second time symbol of the first composite transmission.

[0183] In yet other such embodiments, the base station estimates the channel between the first UE and the base station by taking an average of a plurality of measurements of a plurality of preconfigured symbols of the first composite transmission as a representation of the channel between the first UE and the base station. In some such embodiments, the plurality of preconfigured symbols includes a third time symbol and a fourth time symbol of the first composite transmission.

[0184] Figure 17 A method 1700 of a base station according to an embodiment of the present invention is illustrated. The illustrated method 1700 includes sending 1702 to a first UE and a second UE a DCI indicating that the first UE transmits a first carrier on a first subcarrier during a time slot and that the second UE transmits a second carrier on a second subcarrier during the time slot. The method 1700 also includes receiving 1704 during the time slot: a first composite transmission on the first subcarrier, the first composite transmission including the first carrier as transmitted by the first UE and a first backscatter generated by a first ambient IoT tag from the first carrier; and a second composite transmission on the second subcarrier, the second composite transmission including the second carrier as transmitted by the second UE and a second backscatter generated by a second ambient IoT tag from the second carrier. The method 1700 also includes decoding 1706 first data of the first ambient IoT tag from the first backscatter. The method 1700 also includes decoding 1708 second data of the second ambient IoT tag from the second backscatter.

[0185] In some embodiments, method 1700 further includes isolating the first backscatter from the first composite transmission by estimating a channel between the first UE and the base station, determining a portion of the first composite transmission associated with the first carrier as transmitted by the first UE based on the estimate of the channel between the first UE and the base station, and subtracting the portion of the first composite transmission associated with the first carrier as transmitted by the first UE from the first composite transmission. In some such embodiments, the base station estimates the channel between the first UE and the base station by averaging a sum of a number of symbols of the first composite transmission corresponding to a preamble used in the first backscatter. In some such embodiments, the number of symbols includes a first time symbol of the first composite transmission and a second time symbol of the first composite transmission. In some such embodiments, the number of symbols also includes a third time symbol of the first composite transmission and a fourth time symbol of the first composite transmission.

[0186] In some other such embodiments, the base station estimates the channel between the first UE and the base station by taking a measurement of a preconfigured symbol of the first composite transmission as a representation of the channel between the first UE and the base station. In some such embodiments, the preconfigured symbol comprises a second time symbol of the first composite transmission.

[0187] In yet other such embodiments, the base station estimates the channel between the first UE and the base station by taking an average of a plurality of measurements of a plurality of preconfigured symbols of the first composite transmission as a representation of the channel between the first UE and the base station. In some such embodiments, the plurality of preconfigured symbols includes a third time symbol and a fourth time symbol of the first composite transmission.

[0188] Figure 18 A method 1800 for an environmental IoT tag according to embodiments herein is illustrated. The illustrated method 1800 includes receiving 1802 a carrier wave from a UE. The method 1800 also includes transmitting 1804 backscatter using the carrier wave, wherein the backscatter wave includes a preamble configured to be used in channel estimation of a channel between the UE and a base station that receives the backscatter wave and data from the environmental IoT tag.

[0189] In some embodiments of method 1800, the first portion of the preamble is orthogonal to the second portion of the preamble. In some such embodiments, the first portion of the preamble includes the backscattered first time symbol, and the second portion of the preamble includes the backscattered second time symbol. In some other such embodiments, the first portion of the preamble includes the backscattered first time symbol and the backscattered second time symbol, and the second portion of the preamble includes the backscattered third time symbol and the backscattered fourth time symbol.

[0190] In some embodiments of method 1800, the preamble is configured such that the backscatter includes an unmodulated portion of the carrier wave. In some such embodiments, the unmodulated portion includes the backscattered second time symbol. In some other such embodiments, the unmodulated portion includes the backscattered third time symbol and the backscattered fourth time symbol.

[0191] Figure 19 An exemplary architecture of a wireless communication system 1900 according to the embodiments disclosed herein is shown. The description provided below is for an exemplary wireless communication system 1900 operating in conjunction with the LTE system standard and / or the 5G or NR system standard provided in the 3GPP technical specifications.

[0192] like Figure 19 As shown, the wireless communication system 1900 includes a UE 1902 and a UE 1904 (although any number of UEs may be used). In this example, the UE 1902 and the UE 1904 are shown as smartphones (e.g., handheld touchscreen mobile computing devices capable of connecting to one or more cellular networks), but may also include any mobile or non-mobile computing device configured for wireless communication.

[0193] UE 1902 and UE 1904 may be configured to be communicatively coupled to RAN 1906. In an embodiment, RAN 1906 may be an NG-RAN, E-UTRAN, or the like. UE 1902 and UE 1904 utilize connections (or channels) (shown as connection 1908 and connection 1910, respectively) with RAN 1906, where each connection (or channel) includes a physical communication interface. RAN 1906 may include one or more base stations, such as base station 1912 and base station 1914, that implement connection 1908 and connection 1910.

[0194] In this example, connection 1908 and connection 1910 are the air interfaces that enable such communicative coupling and may conform to the RAT used by RAN 1906, such as LTE and / or NR.

[0195] In some embodiments, UE 1902 and UE 1904 may also directly exchange communication data via side link interface 1916. UE 1904 is shown as being configured to access an access point (shown as AP 1918) via connection 1920. By way of example, connection 1920 may comprise a local wireless connection, such as a connection conforming to any IEEE 802.11 protocol, wherein AP 1918 may comprise a wireless local area network (WLAN) or a wireless local area network (WAN) such as a WLAN 1918. In this example, AP 1918 can connect to another network (eg, the Internet) without going through CN 1924.

[0196] In an embodiment, UE 1902 and UE 1904 may be configured to communicate with each other or with base station 1912 and / or base station 1914 using orthogonal frequency division multiplexing (OFDM) communication signals over a multi-carrier communication channel in accordance with various communication techniques, such as, but not limited to, orthogonal frequency division multiple access (OFDMA) communication techniques (e.g., for downlink communication) or single-carrier frequency division multiple access (SC-FDMA) communication techniques (e.g., for uplink and ProSe or sidelink communication), although the scope of the embodiment is not limited in this respect. An OFDM signal may include multiple orthogonal subcarriers.

[0197] In some embodiments, all or part of base station 1912 or base station 1914 may be implemented as one or more software entities running on a server computer as part of a virtual network. Additionally, or in other embodiments, base station 1912 or base station 1914 may be configured to communicate with each other via interface 1922. In embodiments where wireless communication system 1900 is an LTE system (e.g., when CN 1924 is an EPC), interface 1922 may be an X2 interface. This X2 interface may be defined between two or more base stations (e.g., two or more eNBs, etc.) connected to an EPC and / or between two eNBs connected to an EPC. In embodiments where wireless communication system 1900 is an NR system (e.g., when CN 1924 is a 5GC), interface 1922 may be an Xn interface. This Xn interface is defined between two or more base stations (e.g., two or more gNBs, etc.) connected to a 5GC, between base station 1912 (e.g., a gNB) and an eNB connected to a 5GC, and / or between two eNBs connected to a 5GC (e.g., CN 1924).

[0198] RAN 1906 is shown as being communicatively coupled to CN 1924. CN 1924 may include one or more network elements 1926 configured to provide various data and telecommunication services to customers / subscribers (e.g., UE 1902 and users of UE 1904) connected to CN 1924 via RAN 1906. Components of CN 1924 may be implemented in one physical device or separate physical devices that include components for reading and executing instructions from a machine-readable or computer-readable medium (e.g., a non-transitory machine-readable storage medium).

[0199] In an embodiment, CN 1924 may be an EPC, and RAN 1906 may be connected to CN 1924 via an S1 interface 1928. In an embodiment, S1 interface 1928 may be divided into two parts: an S1 user plane (S1-U) interface, which carries traffic data between base station 1912 or base station 1914 and a serving gateway (S-GW); and an S1-MME interface, which is a signaling interface between base station 1912 or base station 1914 and a mobility management entity (MME).

[0200] In an embodiment, CN 1924 may be a 5GC, and RAN 1906 may be connected to CN 1924 via an NG interface 1928. In an embodiment, NG interface 1928 may be divided into two parts: an NG user plane (NG-U) interface, which carries traffic data between base station 1912 or base station 1914 and a user plane function (UPF); and an S1 control plane (NG-C) interface, which is a signaling interface between base station 1912 or base station 1914 and an access and mobility management function (AMF).

[0201] Generally speaking, the application server 1930 may be an element that provides applications (e.g., packet-switched data services) that utilize Internet Protocol (IP) bearer resources with the CN 1924. The application server 1930 may also be configured to support one or more communication services (e.g., VoIP sessions, group communication sessions, etc.) for the UE 1902 and UE 1904 via the CN 1924. The application server 1930 may communicate with the CN 1924 via an IP communication interface 1932.

[0202] Figure 20 A system 2000 is shown for performing signaling 2034 between a wireless device 2002 and a network device 2018 according to embodiments disclosed herein. System 2000 can be part of a wireless communication system as described herein. Wireless device 2002 can be, for example, a UE of the wireless communication system. Network device 2018 can be, for example, a base station (e.g., an eNB or gNB) of the wireless communication system.

[0203] The wireless device 2002 may include one or more processors 2004. The processor 2004 may execute instructions to cause the wireless device 2002 to perform various operations as described herein. The processor 2004 may include one or more baseband processors implemented using, for example, a central processing unit (CPU), a digital signal processor (DSP), an application specific integrated circuit (ASIC), a controller, a field programmable gate array (FPGA) device, another hardware device, a firmware device, or any combination thereof configured to perform the operations described herein.

[0204] The wireless device 2002 may include a memory 2006. The memory 2006 may be a non-transitory computer-readable storage medium that stores instructions 2008 (these instructions may include, for example, instructions executed by the processor 2004). The instructions 2008 may also be referred to as program code or a computer program. The memory 2006 may also store data used by the processor 2004 and results computed by the processor.

[0205] The wireless device 2002 may include one or more transceivers 2010, which may include radio frequency (RF) transmitter circuitry and / or receiver circuitry that uses an antenna 2012 of the wireless device 2002 to facilitate signaling (e.g., signaling 2034) transmitted or received by the wireless device 2002 to or from other devices (e.g., network device 2018) in accordance with a corresponding RAT.

[0206] The wireless device 2002 may include one or more antennas 2012 (e.g., one, two, four, or more). For embodiments with multiple antennas 2012, the wireless device 2002 may take advantage of the spatial diversity of such multiple antennas 2012 to transmit and / or receive multiple different data streams on the same time-frequency resources. This behavior may be referred to as, for example, multiple-input multiple-output (MIMO) behavior (referring to the multiple antennas used at each of the transmitting device and the receiving device to implement this aspect). MIMO transmissions performed by the wireless device 2002 may be implemented based on precoding (or digital beamforming) applied to the wireless device 2002, which multiplexes the data streams between the antennas 2012 based on known or assumed channel characteristics, such that each data stream is received with appropriate signal strength relative to the other streams and at a desired location in the spatial domain (e.g., the location of the receiver associated with the data stream). Certain embodiments may use single-user MIMO (SU-MIMO) methods (where data streams are all directed to a single receiver) and / or multi-user MIMO (MU-MIMO) methods (where separate data streams may be directed to separate (different) receivers in different locations in the spatial domain).

[0207] In certain embodiments with multiple antennas, the wireless device 2002 may implement analog beamforming techniques whereby the phases of the signals transmitted by the antennas 2012 are relatively adjusted such that the (joint) transmissions from the antennas 2012 are directional (this is sometimes referred to as beam steering).

[0208] The wireless device 2002 may include one or more interfaces 2014. The interfaces 2014 may be used to provide input to the wireless device 2002 or output from the wireless device. For example, the wireless device 2002 as a UE may include an interface 2014, such as a microphone, a speaker, a touch screen, buttons, etc., to allow a user of the UE to input and / or output to the UE. Other interfaces of such a UE may be composed of transmitters, receivers, and other circuits that allow communication between the UE and other devices (for example, in addition to the transceiver 2010 / antenna 2012 already described), and may be based on known protocols (for example, etc.) to perform the operation.

[0209] The wireless device 2002 may include an ambient IoT transmission module 2016. The ambient IoT transmission module 2016 may be implemented via hardware, software, or a combination thereof. For example, the ambient IoT transmission module 2016 may be implemented as a processor, circuitry, and / or instructions 2008 stored in the memory 2006 and executed by the processor 2004. In some examples, the ambient IoT transmission module 2016 may be integrated within the processor 2004 and / or the transceiver 2010. For example, the ambient IoT transmission module 2016 may be implemented via a combination of software components (e.g., executed by a DSP or general-purpose processor) and hardware components (e.g., logic gates and circuits) within the processor 2004 or the transceiver 2010.

[0210] The ambient IoT transmission module 2016 may be used in various aspects of the present disclosure, for example, Figures 1 to 18 In some cases, the ambient IoT transmission module 2016 can be configured to cause the wireless device 2002 to receive a trigger message identifying a first set of ambient IoT resources from the first network device 2018. The ambient IoT transmission module 2016 can also be configured to cause the wireless device 2002 to receive a carrier in the first set of ambient IoT resources. The ambient IoT transmission module 2016 can also be configured to cause the wireless device 2002 to generate a first backscatter signal in a first resource of the first set of ambient IoT resources using the carrier.

[0211] In some other cases, the ambient IoT transmission module 2016 may be configured to cause the wireless device 2002 to receive a carrier wave from the wireless device 2002 and use the carrier wave to transmit backscatter, where the backscatter includes a preamble configured to be used in channel estimation of a channel between the wireless device 2002 and a network device 2018 that receives the backscatter and data from the ambient IoT tag.

[0212] The network device 2018 may include one or more processors 2020. The processors 2020 may execute instructions to cause the network device 2018 to perform various operations as described herein. The processors 2020 may include one or more baseband processors implemented using, for example, a CPU, a DSP, an ASIC, a controller, an FPGA device, another hardware device, a firmware device, or any combination thereof configured to perform the operations described herein.

[0213] Network device 2018 may include memory 2022. Memory 2022 may be a non-transitory computer-readable storage medium that stores instructions 2024 (these instructions may include, for example, instructions to be executed by processor 2020). Instructions 2024 may also be referred to as program code or a computer program. Memory 2022 may also store data used by processor 2020 and results computed by the processor.

[0214] The network device 2018 may include one or more transceivers 2026, which may include RF transmitter circuitry and / or receiver circuitry that uses an antenna 2028 of the network device 2018 to facilitate signaling (e.g., signaling 2034) transmitted or received by the network device 2018 with other devices (e.g., wireless device 2002) according to a corresponding RAT.

[0215] The network device 2018 may include one or more antennas 2028 (e.g., one, two, four, or more). In embodiments with multiple antennas 2028, the network device 2018 may perform MIMO, digital beamforming, analog beamforming, beam steering, etc., as described above.

[0216] The network device 2018 may include one or more interfaces 2030. The interface 2030 may be used to provide input to or output from the network device 2018. For example, a network device 2018 serving as a base station may include an interface 2030 comprised of a transmitter, a receiver, and other circuits (e.g., in addition to the transceiver 2026 / antenna 2028 already described), which enables the base station to communicate with other equipment in the core network and / or enables the base station to communicate with external networks, computers, databases, etc., for the purpose of operating, managing, and maintaining the base station or other equipment operably connected to the base station.

[0217] The network device 2018 may include an ambient IoT transmission module 2032. The ambient IoT transmission module 2032 may be implemented via hardware, software, or a combination thereof. For example, the ambient IoT transmission module 2032 may be implemented as a processor, circuitry, and / or instructions 2024 stored in the memory 2022 and executed by the processor 2020. In some examples, the ambient IoT transmission module 2032 may be integrated within the processor 2020 and / or the transceiver 2026. For example, the ambient IoT transmission module 2032 may be implemented via a combination of software components (e.g., executed by a DSP or general-purpose processor) and hardware components (e.g., logic gates and circuitry) within the processor 2020 or the transceiver 2026.

[0218] The ambient IoT transmission module 2032 may be used in various aspects of the present disclosure, for example, Figures 1 to 18 In some cases, the ambient IoT transmission module 2032 is configured to cause the network device 2018 to send a trigger message identifying a first set of ambient IoT resources to the first wireless device 2002. The ambient IoT transmission module 2032 may also be configured to cause the network device 2018 to receive, in a first resource of the first set of ambient IoT resources, a first backscatter signal derived from a carrier wave by a first ambient IoT tag. The ambient IoT transmission module 2032 may also be configured to cause the network device 2018 to decode first data of the first ambient IoT tag from the first backscatter signal.

[0219] In some other cases, the ambient IoT transmission module 2032 may be configured to cause the network device 2018 to transmit a first DCI to the first wireless device 2002 instructing the first UE to transmit a first carrier of a first frequency tone during a time slot. The ambient IoT transmission module 2032 may also be configured to cause the network device 2018 to transmit a second DCI to the second wireless device 2002 instructing the second UE to transmit a second carrier of a second frequency tone during the time slot, and to receive, during the time slot: a first composite transmission on the first frequency tone, the first composite transmission comprising the first carrier, as transmitted by the first UE, and a first backscatter generated by the first ambient IoT tag from the first carrier; and a second composite transmission on the second frequency tone, the second composite transmission comprising the second carrier, as transmitted by the second UE, and a second backscatter generated by the second ambient IoT tag from the second carrier. The ambient IoT transmission module 2032 may also be configured to cause the network device 2018 to decode first data from the first ambient IoT tag from the first backscatter and second data from the second ambient IoT tag from the second backscatter.

[0220] In still other cases, the ambient IoT transmission module 2032 can be configured to cause the network device 2018 to send a DCI to the first wireless device 2002 and the second wireless device 2002, indicating that the first UE transmits a first carrier of a first frequency tone during a time slot and the second UE transmits a second carrier of a second frequency tone during the time slot, and to receive, during the time slot: a first composite transmission on the first frequency tone, the first composite transmission comprising the first carrier as transmitted by the first UE and a first backscatter generated by the first ambient IoT tag from the first carrier; and a second composite transmission on the second frequency tone, the second composite transmission comprising the second carrier as transmitted by the second UE and a second backscatter generated by the second ambient IoT tag from the second carrier. The ambient IoT transmission module 2032 can also be configured to cause the network device 2018 to decode first data of the first ambient IoT tag from the first backscatter and second data of the second ambient IoT tag from the second backscatter.

[0221] Embodiments contemplated herein include an apparatus comprising means for performing one or more elements of methods 1500 and 1800. The apparatus may be, for example, an apparatus that is a UE (such as wireless device 2002 as a UE, as described herein).

[0222] The embodiments contemplated herein include one or more non-transitory computer-readable media including instructions that, when executed by one or more processors of an electronic device, cause the electronic device to perform one or more elements of method 1500 and method 1800. The non-transitory computer-readable medium may be, for example, a memory of a UE (such as memory 2006 of wireless device 2002 as a UE, as described herein).

[0223] Embodiments contemplated herein include an apparatus comprising logic, modules, or circuitry operable to perform one or more elements of methods 1500 and 1800. The apparatus may be, for example, an apparatus that is a UE (such as wireless device 2002 as a UE, as described herein).

[0224] Embodiments contemplated herein include an apparatus comprising: one or more processors and one or more computer-readable media comprising instructions that, when executed by the one or more processors, cause the one or more processors to perform one or more elements of method 1500 and method 1800. The apparatus may be, for example, an apparatus that is a UE (such as wireless device 2002 as a UE, as described herein).

[0225] Embodiments contemplated herein include a signal as described in or associated with one or more elements of method 1500 and / or method 1800 .

[0226] The embodiments contemplated herein include a computer program or computer program product comprising instructions, wherein execution of the program by a processor causes the processor to perform one or more elements of the methods 1500 and 1800. The processor may be a processor of a UE (such as the processor 2004 of the wireless device 2002 as a UE, as described herein). These instructions may be located, for example, in the processor of the UE and / or on a memory (such as the memory 2006 of the wireless device 2002 as a UE, as described herein).

[0227] Embodiments contemplated herein include an apparatus comprising means for performing one or more elements of method 1400, method 1600, and method 1700. The apparatus may be, for example, an apparatus that is a base station (such as network device 2018 as a base station, as described herein).

[0228] The embodiments contemplated herein include one or more non-transitory computer-readable media including instructions that, when executed by one or more processors of an electronic device, cause the electronic device to perform one or more elements of method 1400, method 1600, and method 1700. The non-transitory computer-readable medium may be, for example, a memory of a base station (such as memory 2022 of network device 2018 acting as a base station, as described herein).

[0229] Embodiments contemplated herein include an apparatus comprising logic, modules, or circuitry operable to perform one or more elements of method 1400, method 1600, and method 1700. The apparatus may be, for example, an apparatus that is a base station (such as network device 2018 as a base station, as described herein).

[0230] Embodiments contemplated herein include an apparatus comprising: one or more processors and one or more computer-readable media comprising instructions that, when executed by the one or more processors, cause the one or more processors to perform one or more elements of method 1400, method 1600, and method 1700. The apparatus may be, for example, an apparatus that is a base station (such as network device 2018 as a base station, as described herein).

[0231] Embodiments contemplated herein include signals as described in or associated with one or more elements of method 1400 , method 1600 , and method 1700 .

[0232] The embodiments contemplated herein include a computer program or computer program product comprising instructions, wherein execution of the program by a processing element causes the processing element to perform one or more elements of methods 1400, 1600, and 1700. The processor may be a processor of a base station (such as processor 2020 of network device 2018 as a base station, as described herein). These instructions may be located, for example, in a processor and / or on a memory of a base station (such as memory 2022 of network device 2018 as a base station, as described herein).

[0233] For one or more embodiments, at least one of the components described in one or more of the preceding figures may be configured to perform one or more operations, techniques, processes, and / or methods as described herein. For example, a baseband processor as described herein in conjunction with one or more of the preceding figures may be configured to operate according to one or more of the examples described herein. For another example, circuitry associated with a UE, base station, network element, etc. as described above in conjunction with one or more of the preceding figures may be configured to operate according to one or more of the examples described herein.

[0234] Unless otherwise expressly stated, any of the above embodiments may be combined with any other embodiment (or combination of embodiments). The foregoing description of one or more specific implementations provides illustration and description, but is not intended to be exhaustive or to limit the scope of the embodiments to the precise forms disclosed. In view of the above teachings, modifications and variations are possible or can be obtained from the practice of the various embodiments.

[0235] Embodiments and implementations of the systems and methods described herein may include various operations that may be embodied in machine-executable instructions to be executed by a computer system. A computer system may include one or more general-purpose or special-purpose computers (or other electronic devices). A computer system may include hardware components that include specific logic components for performing the operations; or may include a combination of hardware, software, and / or firmware.

[0236] It should be understood that the systems described herein include descriptions of specific embodiments. These embodiments can be combined into a single system, partially combined into other systems, separated into multiple systems, or divided or combined in other ways. In addition, it is contemplated that parameters, attributes, aspects, etc. of one embodiment may be used in another embodiment. For clarity, these parameters, attributes, aspects, etc. are described only in one or more embodiments, and it should be understood that unless expressly stated otherwise herein, these parameters, attributes, aspects, etc. may be combined with or substituted for parameters, attributes, aspects, etc. of another embodiment.

[0237] It is understood that the use of personally identifiable information should be subject to privacy policies and practices that are generally recognized to meet or exceed industry or government requirements for maintaining user privacy. Specifically, personally identifiable information data should be managed and processed to minimize the risk of unintentional or unauthorized access or use, and the nature of authorized use should be clearly stated to users.

[0238] Although the foregoing has been described in considerable detail for purposes of clarity, it will be apparent that certain changes and modifications may be made without departing from the principles of the invention. It should be noted that there are many alternative ways of implementing both the processes and the apparatus described herein. Therefore, the embodiments of the present invention are to be considered illustrative and not restrictive, and the description is not to be limited to the details given herein, but may be modified within the scope and equivalents of the appended claims.

Claims

1. A method for a base station, the method comprising: Sending a trigger message identifying a first environment IoT resource set to a first environment Internet of Things (IoT) tag; receiving, in a first resource of the first set of ambient IoT resources, a first backscatter derived from a carrier by the first ambient IoT tag; as well as First data of the first environmental IoT tag is decoded from the first backscatter. 2 . The method according to claim 1 , further comprising transmitting the carrier in the first environment IoT resource set. 3 . The method according to claim 1 , further comprising sending an instruction to transmit the carrier in the first environment IoT resource set to an auxiliary device. 4 . The method of claim 1 , wherein the trigger message comprises a first indication that the first environmental IoT tag is to generate the first backscatter.

5. The method according to claim 1, wherein the trigger message is sent to a second environment IoT tag, and the method further comprises: receiving, in a second resource of the first set of ambient IoT resources, a second backscatter derived from the carrier by the second ambient IoT tag; as well as Second data of the second environmental IoT tag is decoded from the second backscatter. 6 . The method according to claim 5 , wherein the trigger message further comprises a second indication that the second environmental IoT tag is to generate the second backscatter.

7. The method of claim 1 , wherein the trigger message further identifies a second set of ambient IoT resources in which no carrier is transmitted; and the method further comprises receiving a transmission in a second resource of the second set of ambient IoT resources from a second ambient IoT tag. The method according to claim 7 , wherein the first set of ambient IoT resources and the second set of ambient IoT resources are separated in a time domain. 9 . The method of claim 7 , wherein the first set of ambient IoT resources and the second set of ambient IoT resources are overlapped in a time domain and separated in a frequency domain.

10. The method of claim 9, wherein the first set of ambient IoT resources is located on a frequency tone used by the carrier. The method according to claim 9 , wherein the first set of environmental IoT resources is located on a frequency modulation sequence used by the carrier.

12. The method of claim 1, wherein the trigger message includes a synchronization preamble for acquiring a frequency and timing corresponding to the carrier.

13. A method for environmental Internet of Things (IoT) tagging, the method comprising: receiving a trigger message identifying a first environment IoT resource set from a first base station; receiving a carrier wave in the first environment IoT resource set; as well as A first backscatter is generated in a first resource of the first set of environmental IoT resources using the carrier. The method of claim 13 , wherein the carrier is received from the base station.

15. The method of claim 13, wherein the carrier is received from a secondary device. The method of claim 13 , wherein the trigger message comprises a first indication that the first environmental IoT tag is to generate the first backscatter. 17 . The method according to claim 16 , further comprising randomly selecting the first resource of the first environmental IoT resource set from one or more resources of the first environmental IoT resource set.

18. The method of claim 16, wherein the trigger message further includes a second indication that a second environmental IoT tag is to generate a second backscatter.

19. The method of claim 16, wherein the trigger message further identifies a second set of ambient IoT resources in which no carrier is transmitted. 20 . The method of claim 19 , wherein the first set of ambient IoT resources and the second set of ambient IoT resources are separated in a time domain. 21 . The method of claim 19 , wherein the first set of ambient IoT resources and the second set of ambient IoT resources are overlapping in a time domain and separated in a frequency domain.

22. The method of claim 21, wherein the first set of ambient IoT resources is located on a frequency tone, and wherein the carrier is received on the frequency tone.

23. The method of claim 21, wherein the first set of ambient IoT resources is located on a frequency-tone sequence, and wherein the carrier is received on the frequency-tone sequence.

24. The method of claim 13, wherein the trigger message includes a synchronization preamble for acquiring a frequency and timing corresponding to the carrier.

25. An apparatus comprising means for performing the method according to any one of claims 1 to 24.

26. A computer-readable medium comprising instructions, which, when executed by one or more processors of an electronic device, cause the electronic device to perform the method according to any one of claims 1 to 24.

27. An apparatus comprising logic components, modules or circuits operable to perform the method of any one of claims 1 to 24.

28. A baseband processor for a base station, the baseband processor being configured to cause the base station to execute one or more elements according to any one of claims 1 to 12.

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