Method and procedure for estimating and compensating for time and frequency offsets in wireless communications networks

Abstract

Apparatuses, systems, and methods for performing offset estimation are described. An apparatus may select reference signals and generate a reference waveform based on the selected reference signals. The apparatus may determine an offset by correlating the references signals in the reference waveform with the reference signals in a received OFDM transmission. The offset may be a time offset. The offset may be a frequency offset.

Description

METHOD AND PROCEDURE FORESTIMATING AND COMPENSATING FOR TIME AND FREQUENCY OFFSETS IN WIRELESS COMMUNICATIONS NETWORKSFIELD

[0001] The invention relates to wireless communications, and more particularly to apparatuses, systems, and methods for estimating and compensating for time and frequency offsets.DESCRIPTION OF THE RELATED ART

[0002] Wireless communication systems are rapidly growing in usage. In recent years, wireless devices such as smart phones and tablet computers have become increasingly sophisticated. In addition to supporting telephone calls, many mobile devices now provide access to the internet, email, text messaging, and navigation using the global positioning system (GPS), and are capable of operating sophisticated applications that utilize these functionalities. Additionally, there exist numerous different wireless communication technologies and standards.

[0003] Long Term Evolution (LTE), also referred to as the Evolved Universal Terrestrial Radio Access Network (E-UTRAN, has been the technology of choice for the majority of wireless network operators worldwide, providing mobile broadband data and high-speed Internet access to their subscriber base. LTE was first proposed in 2004 and was first standardized in 2008. Since then, as usage of wireless communication systems has expanded exponentially, demand has risen for wireless network operators to support a higher capacity for a higher density of mobile broadband users. Thus, in 2015 study of a new radio access technology began and, in 2017, a first release of the Third Generation Partnership Project (3GPP) Fifth Generation New Radio (5G NR) was standardized. 5th generation mobile networks or 5th generation wireless systems, referred to as 3GPP NR (otherwise known as 5G-NR or NR-5G for 5G New Radio, also simply referred to as NR). NR proposes a higher capacity for a higher density of mobile broadband users, also supporting device-to-device, ultra-reliable, and massive machine communications, as well as lower latency and lower battery consumption, than LTE standards.

[0004] 5G-NR provides, as compared to LTE, a higher capacity for a higher density of mobile broadband users, while also supporting device-to-device, ultra-reliable, and massive machine type communications with lower latency and / or lower battery consumption. Further, NR may allow for more flexible UE scheduling as compared to current LTE. Consequently, efforts are being made in ongoing developments of 5G-NR to take advantage of higher throughputs possible at higher frequencies.

[0005] One aspect of wireless communication systems, including, for example, systems for NR cellular wireless communications, Wi-Fi networks, and terrestrial / non-terrestrial wireless communications systems, is the transmission and measurement of reference signals to compensate for time and frequency offsets.SUMMARY

[0006] Embodiments relate to wireless communications, and more particularly to apparatuses, systems, and methods for estimating and compensating for time offsets (TO) and frequency offsets (FO).

[0007] Embodiments relate to wireless communications, and more particularly to apparatuses, systems, and methods for a device configured for communicating in a wireless communication network, comprising: one or more processors, coupled to a memory, configured to: select a first reference signal corresponding to a first type; select one or more additional reference signals; generate a reference waveform based on the first reference signal and the one or more additional reference signals; receive an orthogonal frequency division multiplexing (OFDM) waveform including the first reference signal and the one or more additional reference signals; and determine an offset by correlating the references signals in the reference waveform with the reference signals in the received OFDM transmission.

[0008] Other embodiments relate to a user equipment comprising: one or more processors, coupled to a memory, configured to: select a first reference signal corresponding to a first type; select one or more additional reference signals; generate a reference waveform based on the first reference signal and the one or more additional reference signals; receive an orthogonal frequency division multiplexing (OFDM) waveform including the first reference signal and the one or more additional referencesignals; and determine an offset by correlating the references signals in the reference waveform with the reference signals in the received OFDM transmission.

[0009] The techniques described herein may be implemented in and / or used with a number of different types of devices, including but not limited to base stations, access points, cellular phones, tablet, laptop, and desktop computers, wearable computing devices, portable media players, vehicles, and any of various other computing devices.

[0010] This Summary is intended to provide a brief overview of some of the subject matter described in this document. Accordingly, it will be appreciated that the abovedescribed features are merely examples and should not be construed to narrow the scope or spirit of the subject matter described herein in any way. Other features, aspects, and advantages of the subject matter described herein will become apparent from the following Detailed Description, Figures, and Claims.BRIEF DESCRIPTION OF THE DRAWINGS

[0011] A better understanding of the present subject matter can be obtained when the following detailed description of various embodiments is considered in conjunction with the following drawings, in which:

[0012] FIG. 1 A illustrates an example wireless communication system according to some embodiments.

[0013] FIG. IB illustrates an example of a base station and an access point in communication with a user equipment (UE) device, according to some embodiments.

[0014] FIG. 2 illustrates an example block diagram of a base station, according to some embodiments.

[0015] FIG. 3 illustrates an example block diagram of a server according to some embodiments.

[0016] FIG. 4 illustrates an example block diagram of a UE according to some embodiments.

[0017] FIG. 5 illustrates an example block diagram of cellular communication circuitry, according to some embodiments.

[0018] FIG. 6A illustrates an example of a 5G network architecture that incorporatesboth 3GPP (e.g., cellular) and non-3GPP (e.g., non-cellular) access to the 5G CN and / or the internet 600, according to some embodiments.

[0019] FIG. 6B illustrates an example of a 5G network architecture that incorporates both dual 3GPP (e.g., LTE and 5G NR) access and non-3GPP access to the 5G CN and / or the internet 600, according to some embodiments.

[0020] FIG. 7 illustrates an example of a baseband processor architecture for a UE, according to some embodiments.

[0021] FIG. 8 illustrates an example of a device in accordance with some embodiments.

[0022] FIG. 9 illustrates an example baseband circuitry in accordance with some embodiments.

[0023] FIG. 10 illustrates an example of a control plane protocol stack in accordance with some embodiments.

[0024] FIG. 11 illustrates an example of reference signals within a resource grid in accordance with some embodiments.

[0025] FIG. 12 illustrates an example of a preamble sequence and a pilot symbols within a resource grid in accordance with some embodiments.

[0026] FIG. 13 illustrates an example of references signals within a resource grid of a transmission cycle in accordance with some embodiments.

[0027] FIG. 14 illustrates an example wireless communication system in accordance with some embodiments.

[0028] FIG. 15 illustrates an example of a reference waveform in the time domain in accordance with some embodiments.

[0029] FIG. 16 illustrates an example of a reference waveform in the time domain in accordance with some embodiments.

[0030] FIGs. 17A-17B are conceptual diagrams illustrating correlating a reference waveform and a received waveform in accordance with some embodiments.

[0031] FIG. 18 illustrates a block diagram of an example of a method to perform offset estimation, according to some embodiments.

[0032] While the features described herein may be susceptible to various modificationsand alternative forms, specific embodiments thereof are shown by way of example in the drawings and are herein described in detail. It should be understood, however, that the drawings and detailed description thereto are not intended to be limiting to the particular form disclosed, but on the contrary, the intention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the subject matter as defined by the appended claims.DETAILED DESCRIPTION

[0033] The following is a glossary of terms used in this disclosure:

[0034] Memory Medium - Any of various types of non-transitory memory devices or storage devices. The term “memory medium” is intended to include an installation medium, e.g., a CD- ROM, floppy disks, or tape device; a computer system memory or randomaccess memory such as DRAM, DDR RAM, SRAM, EDO RAM, Rambus RAM, etc.; a non-volatile memory such as a Flash, magnetic media, e.g., a hard drive, or optical storage; registers, or other similar types of memory elements, etc. The memory medium may include other types of non-transitory memory as well or combinations thereof. In addition, the memory medium may be located in a first computer system in which the programs are executed, or may be located in a second different computer system which connects to the first computer system over a network, such as the Internet. In the latter instance, the second computer system may provide program instructions to the first computer for execution. The term “memory medium” may include two or more memory mediums which may reside in different locations, e.g., in different computer systems that are connected over a network. The memory medium may store program instructions (e.g., embodied as computer programs) that may be executed by one or more processors.

[0035] Carrier Medium - a memory medium as described above, as well as a physical transmission medium, such as a bus, network, and / or other physical transmission medium that conveys signals such as electrical, electromagnetic, or digital signals.

[0036] Programmable Hardware Element - includes various hardware devices comprising multiple programmable function blocks connected via a programmable interconnect. Examples include FPGAs (Field Programmable Gate Arrays), PLDs (Programmable Logic Devices), FPOAs (Field Programmable Object Arrays), and CPLDs(Complex PLDs). The programmable function blocks may range from fine grained (combinatorial logic or look up tables) to coarse grained (arithmetic logic units or processor cores). A programmable hardware element may also be referred to as "reconfigurable logic”.

[0037] Computer System (or Computer) - any of various types of computing or processing systems, including a personal computer system (PC), mainframe computer system, workstation, network appliance, Internet appliance, personal digital assistant (PDA), television system, grid computing system, or other device or combinations of devices. In general, the term "computer system" can be broadly defined to encompass any device (or combination of devices) having at least one processor that executes instructions from a memory medium.

[0038] User Equipment (UE) (or “UE Device”) - any of various types of computer systems devices which are mobile or portable and which performs wireless communications. Examples of UE devices include mobile telephones or smart phones (e.g., iPhone™, Android™-based phones), portable gaming devices (e.g., Nintendo DS™, PlayStation Portable™, Gameboy Advance™, iPhone™), laptops, wearable devices (e.g., smart watch, smart glasses), PDAs, portable Internet devices, music players, data storage devices, other handheld devices, unmanned aerial vehicles (UAVs) (e.g., drones), UAV controllers (UACs), and so forth. In general, the term “UE” or “UE device” can be broadly defined to encompass any electronic, computing, and / or telecommunications device (or combination of devices) which is easily transported by a user and capable of wireless communication.

[0039] Base Station - The term "Base Station" has the full breadth of its ordinary meaning, and at least includes a wireless communication station installed at a fixed location and used to communicate as part of a wireless telephone system or radio system.

[0040] Processing Element (or Processor) - refers to various elements or combinations of elements that are capable of performing a function in a device, such as a user equipment or a cellular network device. Processing elements may include, for example: processors and associated memory, portions or circuits of individual processor cores, entire processor cores, processor arrays, circuits such as an ASIC (Application Specific Integrated Circuit), programmable hardware elements such as a field programmable gate array (FPGA), as well any of various combinations of the above.

[0041] Channel - a medium used to convey information from a sender (transmitter) to a receiver. It should be noted that since characteristics of the term “channel” may differ according to different wireless protocols, the term “channel” as used herein may be considered as being used in a manner that is consistent with the standard of the type of device with reference to which the term is used. In some standards, channel widths may be variable (e.g., depending on device capability, band conditions, etc.). For example, LTE may support scalable channel bandwidths from 1.4 MHz to 20MHz. In contrast, WLAN channels may be 22MHz wide while Bluetooth channels may be IMhz wide. Other protocols and standards may include different definitions of channels. Furthermore, some standards may define and use multiple types of channels, e.g., different channels for uplink or downlink and / or different channels for different uses such as data, control information, etc.

[0042] Band - The term "band" has the full breadth of its ordinary meaning, and at least includes a section of spectrum (e.g., radio frequency spectrum) in which channels are used or set aside for the same purpose.

[0043] Wi-Fi - The term "Wi-Fi" (or WiFi) has the full breadth of its ordinary meaning, and at least includes a wireless communication network or RAT that is serviced by wireless LAN (WLAN) access points and which provides connectivity through these access points to the Internet. Most modem Wi-Fi networks (or WLAN networks) are based on IEEE 802.11 standards and are marketed under the name “Wi-Fi”. A Wi-Fi (WLAN) network is different from a cellular network.

[0044] 3GPP Access - refers to accesses (e.g., radio access technologies) that are specified by the Third Generation Partnership Project (3GPP) standards. These accesses include, but are not limited to, GSM / GPRS, LTE, LTE-A, and / or 5G NR. In general, 3GPP access refers to various types of cellular access technologies.

[0045] Non-3GPP Access - refers any accesses (e.g., radio access technologies) that are not specified by 3GPP standards. These accesses include, but are not limited to, WiMAX, CDMA2000, Wi-Fi, WLAN, and / or fixed networks. Non-3GPP accesses may be split into two categories, "trusted" and "untrusted": Trusted non-3GPP accesses can interact directly with an evolved packet core (EPC) and / or a 5G core (5GC) whereas untrusted non-3GPP accesses interwork with the EPC / 5GC via a network entity, such as an Evolved Packet Data Gateway and / or a 5G NR gateway. In general, non-3GPP access refersto various types on non-cellular access technologies.

[0046] Automatically - refers to an action or operation performed by a computer system (e.g., software executed by the computer system) or device (e.g., circuitry, programmable hardware elements, ASICs, etc.), without user input directly specifying or performing the action or operation. Thus, the term "automatically" is in contrast to an operation being manually performed or specified by the user, where the user provides input to directly perform the operation. An automatic procedure may be initiated by input provided by the user, but the subsequent actions that are performed “automatically” are not specified by the user, i.e., are not performed “manually”, where the user specifies each action to perform. For example, a user filling out an electronic form by selecting each field and providing input specifying information (e.g., by typing information, selecting check boxes, radio selections, etc.) is filling out the form manually, even though the computer system can update the form in response to the user actions. The form may be automatically filled out by the computer system where the computer system (e.g., software executing on the computer system) analyzes the fields of the form and fills in the form without any user input specifying the answers to the fields. As indicated above, the user may invoke the automatic filling of the form, but is not involved in the actual filling of the form (e.g., the user is not manually specifying answers to fields but rather they are being automatically completed). The present specification provides various examples of operations being automatically performed in response to actions the user has taken.

[0047] Approximately - refers to a value that is almost correct or exact. For example, approximately may refer to a value that is within 1 to 10 percent of the exact (or desired) value. It should be noted, however, that the actual threshold value (or tolerance) may be application dependent. For example, in some embodiments, “approximately” may mean within 0.1% of some specified or desired value, while in various other embodiments, the threshold may be, for example, 2%, 3%, 5%, and so forth, as desired or as used by the particular application.

[0048] Concurrent - refers to parallel execution or performance, where tasks, processes, or programs are performed in an at least partially overlapping manner. For example, concurrency may be implemented using “strong” or strict parallelism, where tasks are performed (at least partially) in parallel on respective computational elements, or using “weak parallelism”, where the tasks are performed in an interleaved manner, e.g., bytime multiplexing of execution threads.

[0049] Various components may be described as “configured to” perform a task or tasks. In such contexts, “configured to” is a broad recitation generally meaning “having structure that” performs the task or tasks during operation. As such, the component can be configured to perform the task even when the component is not currently performing that task (e.g., a set of electrical conductors may be configured to electrically connect a module to another module, even when the two modules are not connected). In some contexts, “configured to” may be a broad recitation of structure generally meaning “having circuitry that” performs the task or tasks during operation. As such, the component can be configured to perform the task even when the component is not currently on. In general, the circuitry that forms the structure corresponding to “configured to” may include hardware circuits.

[0050] Various components may be described as performing a task or tasks, for convenience in the description. Such descriptions should be interpreted as including the phrase “configured to.” Reciting a component that is configured to perform one or more tasks is expressly intended not to invoke 35 U.S.C. § 112(f) interpretation for that component.FIGs. 1A and IB: Communication Systems

[0051] FIG. 1A illustrates a simplified example wireless communication system, according to some embodiments. It is noted that the system of FIG. 1A is merely one example of a possible system, and that features of this disclosure may be implemented in any of various systems, as desired.

[0052] As shown, the example wireless communication system includes a base station 102A which communicates over a transmission medium with one or more user equpiment 106A, 106B, etc., through 106N. The user devices may be referred to herein as a “user equipment” (UE). Thus, the user devices 106 are referred to as UEs or UE devices.

[0053] The base station (BS) 102A may be a base transceiver station (BTS) or cell site (a “cellular base station”) and may include hardware that enables wireless communication with the UEs 106A through 106N.

[0054] The communication area (or coverage area) of the base station may be referred to as a “cell.” The base station 102A and the UEs 106 may be configured to communicateover the transmission medium using any of various radio access technologies (RATs), also referred to as wireless communication technologies, or telecommunication standards, such as GSM, UMTS (associated with, for example, WCDMA or TD-SCDMA air interfaces), LTE, LTE-Advanced (LTE-A), 5G new radio (5G NR), HSPA, 3GPP2 CDMA2000 (e.g., IxRTT, IxEV-DO, HRPD, eHRPD), etc. Note that if the base station 102A is implemented in the context of LTE (E-UTRAN), it may alternately be referred to as an 'eNodeB' or ‘eNB’. Note that if the base station 102A is implemented in the context of 5G NR, it may alternately be referred to as *gNodeB’ or *gNB’.

[0055] As shown, the base station 102 A may also be equipped to communicate with a network (NW) 100 (e.g., a core network of a cellular service provider, a telecommunication network such as a public switched telephone network (PSTN), and / or the Internet, among various possibilities). Thus, the base station 102A may facilitate communication between the user devices and / or between the user devices and the network 100. In particular, the cellular base station 102 A may provide UEs 106 with various telecommunication capabilities, such as voice, SMS and / or data services.

[0056] Base station 102 A and other similar base stations (such as base stations 102B...102N) operating according to the same or a different cellular communication standard may thus be provided as a network of cells, which may provide continuous or nearly continuous overlapping service to UEs 106A-N and similar devices over a geographic area via one or more cellular communication standards.

[0057] Thus, while base station 102A may act as a “serving cell” for UEs 106A-N as illustrated in FIG. 1A, each UE 106 may also be capable of receiving signals from (and possibly within communication range of) one or more other cells (which might be provided by base stations 102B-N and / or any other base stations), which may be referred to as “neighboring cells”. Such cells may also be capable of facilitating communication between user devices and / or between user devices and the network 100. Such cells may include “macro” cells, “micro” cells, “pico” cells, and / or cells which provide any of various other granularities of service area size. For example, base stations 102 A-B illustrated in FIG. 1A might be macro cells, while base station 102N might be a micro cell. Other configurations are also possible.

[0058] In some embodiments, base station 102A may be a next generation base station, e.g., a 5G New Radio (5G NR) base station, or “gNB”. In some embodiments, a gNB maybe connected to a legacy evolved packet core (EPC) network and / or to a NR core (NRC) network. In addition, a gNB cell may include one or more transmission and reception points (TRPs). In addition, a UE capable of operating according to 5G NR may be connected to one or more TRPs within one or more gNBs.

[0059] Note that a UE 106 may be capable of communicating using multiple wireless communication standards. For example, the UE 106 may be configured to communicate using a wireless networking (e.g., Wi-Fi) and / or peer-to-peer wireless communication protocol (e.g., Bluetooth, Wi-Fi peer-to-peer, etc.) in addition to at least one cellular communication protocol (e.g., GSM, UMTS (associated with, for example, WCDMA or TD-SCDMA air interfaces), LTE, LTE-A, 5G NR, HSPA, 3GPP2 CDMA2000 (e.g., IxRTT, IxEV-DO, HRPD, eHRPD), etc.). The UE 106 may also or alternatively be configured to communicate using one or more global navigational satellite systems (GNSS, e.g., GPS or GLONASS), one or more mobile television broadcasting standards (e.g., ATSC-M / H or DVB-H), and / or any other wireless communication protocol, if desired. Other combinations of wireless communication standards (including more than two wireless communication standards) are also possible.

[0060] FIG. IB illustrates user equipment 106 (e.g., one of the UEs 106A through 106N) in communication with a base station 102 and an access point 112, according to some embodiments. The UE 106 may be a device with both cellular communication capability and non-cellular communication capability (e.g., Bluetooth, Wi-Fi, and so forth) such as a mobile phone, a hand- held device, a computer or a tablet, or virtually any type of wireless device.

[0061] The UE 106 may include a processor that is configured to execute program instructions stored in memory. The UE 106 may perform any of the method embodiments described herein by executing such stored instructions. Alternatively, or in addition, the UE 106 may include a programmable hardware element such as an FPGA (field -programmable gate array) that is configured to perform any of the method embodiments described herein, or any portion of any of the method embodiments described herein.

[0062] The UE 106 may include one or more antennas for communicating using one or more wireless communication protocols or technologies. In some embodiments, the UE 106 may be configured to communicate using, for example, CDMA2000 (IxRTT I IxEV- DO / HRPD / eHRPD), LTE / LTE- Advanced, or 5G NR using a single shared radio and / orGSM, LTE, LTE- Advanced, or 5G NR using the single shared radio. The shared radio may couple to a single antenna, or may couple to multiple antennas (e.g., for MIMO) for performing wireless communications. In general, a radio may include any combination of a baseband processor, analog RF signal processing circuitry (e.g., including filters, mixers, oscillators, amplifiers, etc.), or digital processing circuitry (e.g., for digital modulation as well as other digital processing). Similarly, the radio may implement one or more receive and transmit chains using the aforementioned hardware. For example, the UE 106 may share one or more parts of a receive and / or transmit chain between multiple wireless communication technologies, such as those discussed above.

[0063] In some embodiments, the UE 106 may include separate transmit and / or receive chains (e.g., including separate antennas and other radio components) for each wireless communication protocol with which it is configured to communicate. As a further possibility, the UE 106 may include one or more radios which are shared between multiple wireless communication protocols, and one or more radios which are used exclusively by a single wireless communication protocol. For example, the UE 106 might include a shared radio for communicating using either of LTE (E-UTRAN) or 5G NR (or LTE or IxRTTor LTE or GSM), and separate radios for communicating using each of Wi-Fi and Bluetooth. Other configurations are also possible.FIG. 2: Block Diagram of a Base Station

[0064] FIG. 2 illustrates an example block diagram of a base station 102, according to some embodiments. It is noted that the base station of FIG. 3 is merely one example of a possible base station. As shown, the base station 102 may include processor(s) 204 which may execute program instructions for the base station 102. The processor(s) 204 may also be coupled to memory management unit (MMU) 240, which may be configured to receive addresses from the processor(s) 204 and translate those addresses to locations in memory (e.g., memory 260 and read only memory (ROM) 250) or to other circuits or devices.

[0065] The base station 102 may include at least one network port 270. The network port 270 may be configured to couple to a telephone network and provide a plurality of devices, such as UE 106, access to the telephone network as described above in FIGs. 1 and 2.

[0066] The network port 270 (or an additional network port) may also or alternatively be configured to couple to a cellular network, e.g., a core network of a cellular service provider. The core network may provide mobility related services and / or other services to a plurality of devices, such as UE 106. In some cases, the network port 270 may couple to a telephone network via the core network, and / or the core network may provide a telephone network (e.g., among other UE serviced by the cellular service provider).

[0067] In some embodiments, base station 102 may be a next generation base station, e.g., a 5G New Radio (5G NR) base station, or “gNB”. In such embodiments, base station 102 may be connected to a legacy evolved packet core (EPC) network and / or to a NR core (NRC) network. In addition, base station 102 may be considered a 5G NR cell and may include one or more transmission and reception points (TRPs). In addition, a UE capable of operating according to 5G NR may be connected to one or more TRPs within one or more gNBs.

[0068] The base station 102 may include at least one antenna 234, and possibly multiple antennas. The at least one antenna 234 may be configured to operate as a wireless transceiver and may be further configured to communicate with UE 106 via radio 230. The antenna 234 communicates with the radio 230 via communication chain 232. Communication chain 232 may be a receive chain, a transmit chain or both. The radio 230 may be configured to communicate via various wireless communication standards, including, but not limited to, 5G NR, LTE, LTE-A, GSM, UMTS, CDMA2000, Wi-Fi, etc.

[0069] The base station 102 may be configured to communicate wirelessly using multiple wireless communication standards. In some instances, the base station 102 may include multiple radios, which may enable the base station 102 to communicate according to multiple wireless communication technologies. For example, as one possibility, the base station 102 may include an LTE radio for performing communication according to LTE as well as a 5G NR radio for performing communication according to 5G NR. In such a case, the base station 102 may be capable of operating as both an LTE base station and a 5G NR base station. As another possibility, the base station 102 may include a multi-mode radio which is capable of performing communications according to any of multiple wireless communication technologies (e.g., 5G NR and Wi-Fi, LTE and Wi-Fi, LTE and UMTS, LTE and CDMA2000, UMTS and GSM, etc.).

[0070] As described further subsequently herein, the BS 102 may include hardware andsoftware components for implementing or supporting implementation of features described herein. The processor 204 of the base station 102 may be configured to implement or support implementation of part or all of the methods described herein, e.g., by executing program instructions stored on a memory medium (e.g., a non-transitory computer-readable memory medium). Alternatively, the processor 204 may be configured as a programmable hardware element, such as an FPGA (Field Programmable Gate Array), or as an ASIC (Application Specific Integrated Circuit), or a combination thereof. Alternatively (or in addition) the processor 204 of the BS 102, in conjunction with one or more of the other components 230, 232, 234, 240, 250, 260, 270 may be configured to implement or support implementation of part or all of the features described herein.

[0071] In addition, as described herein, processor(s) 204 may be comprised of one or more processing elements. In other words, one or more processing elements may be included in processor(s) 204. Thus, processor(s) 204 may include one or more integrated circuits (ICs) that are configured to perform the functions of processor(s) 204. In addition, each integrated circuit may include circuitry (e.g., first circuitry, second circuitry, etc.) configured to perform the functions of processor(s) 204.

[0072] Further, as described herein, radio 230 may be comprised of one or more processing elements. In other words, one or more processing elements may be included in radio 230. Thus, radio 230 may include one or more integrated circuits (ICs) that are configured to perform the functions of radio 230. In addition, each integrated circuit may include circuitry (e.g., first circuitry, second circuitry, etc.) configured to perform the functions of radio 230.FIG. 3 : Block Diagram of a Server

[0073] FIG. 3 illustrates an example block diagram of a server 104, according to some embodiments. It is noted that the server of FIG. 3 is merely one example of a possible server. As shown, the server 104 may include processor(s) 344 which may execute program instructions for the server 104. The processor(s) 344 may also be coupled to memory management unit (MMU) 374, which may be configured to receive addresses from the processor(s) 344 and translate those addresses to locations in memory (e.g., memory 364 and read only memory (ROM) 354) or to other circuits or devices.

[0074] The server 104 may be configured to provide a plurality of devices, such as base station 102 and UE 106 access to network functions, e.g., as further described herein.

[0075] In some embodiments, the server 104 may be part of a radio access network, such as a 5G New Radio (5G NR) radio access network. In some embodiments, the server 104 may be connected to a legacy evolved packet core (EPC) network and / or to a NR core (NRC) network.

[0076] As described further subsequently herein, the server 104 may include hardware and software components for implementing or supporting implementation of features described herein. The processor 344 of the server 104 may be configured to implement or support implementation of part or all of the methods described herein, e.g., by executing program instructions stored on a memory medium (e.g., a non-transitory computer-readable memory medium). Alternatively, the processor 344 may be configured as a programmable hardware element, such as an FPGA (Field Programmable Gate Array), or as an ASIC (Application Specific Integrated Circuit), or a combination thereof. Alternatively (or in addition) the processor 344 of the server 104, in conjunction with one or more of the other components 354, 364, and / or 374 may be configured to implement or support implementation of part or all of the features described herein.

[0077] In addition, as described herein, processor(s) 344 may be comprised of one or more processing elements. In other words, one or more processing elements may be included in processor(s) 344. Thus, processor(s) 344 may include one or more integrated circuits (ICs) that are configured to perform the functions of processor(s) 344. In addition, each integrated circuit may include circuitry (e.g., first circuitry, second circuitry, etc.) configured to perform the functions of processor(s) 344.FIG. 4: Block Diagram of a UE

[0078] FIG. 4 illustrates an example simplified block diagram of a communication device 406, according to some embodiments. It is noted that the block diagram of the communication device of FIG. 4 is only one example of a possible communication device. According to embodiments, communication device 406 may be a user equipment (UE) 106, a mobile device or mobile station, a wireless device or wireless station, a desktop computer or computing device, a mobile computing device (e.g., a laptop, notebook, or portablecomputing device), a tablet, an unmanned aerial vehicle (UAV), a UAV controller (UAC) and / or a combination of devices, among other devices. As shown, the communication device 406 may include a set of components 400 configured to perform core functions. For example, this set of components may be implemented as a system on chip (SOC), which may include portions for various purposes. Alternatively, this set of components 400 may be implemented as separate components or groups of components for the various purposes. The set of components 400 may be coupled (e.g., communicatively; directly or indirectly) to various other circuits of the communication device 406.

[0079] For example, the communication device 406 may include various types of memory (e.g., including NAND flash 410), an input / output interface such as connector I / F 420 (e.g., for connecting to a computer system; dock; charging station; input devices, such as a microphone, camera, keyboard; output devices, such as speakers; etc.), the display 460, which may be integrated with or external to the communication device 406, and cellular communication circuitry 430 such as for 5G NR, LTE, GSM, etc., and short to medium range wireless communication circuitry 429 (e.g., Bluetooth™ and WLAN circuitry). In some embodiments, communication device 406 may include wired communication circuitry (not shown), such as a network interface card, e.g., for Ethernet.

[0080] The cellular communication circuitry 430 may couple (e.g., communicatively; directly or indirectly) to one or more antennas, such as antennas 435 and 436 as shown. The short to medium range wireless communication circuitry 429 may also couple (e.g., communicatively; directly or indirectly) to one or more antennas, such as antennas 437 and 438 as shown. Alternatively, the short to medium range wireless communication circuitry 429 may couple (e.g., communicatively; directly or indirectly) to the antennas 435 and 436 in addition to, or instead of, coupling (e.g., communicatively; directly or indirectly) to the antennas 437 and 438. The short to medium range wireless communication circuitry 429 and / or cellular communication circuitry 430 may include multiple receive chains and / or multiple transmit chains for receiving and / or transmitting multiple spatial streams, such as in a multiple-input multiple output (MIMO) configuration.

[0081] In some embodiments, as further described below, cellular communication circuitry 430 may include dedicated receive chains (including and / or coupled to, e.g., communicatively; directly or indirectly, dedicated processors and / or radios) for multiple RATs (e.g., a first receive chain for LTE and a second receive chain for 5G NR). In addition,in some embodiments, cellular communication circuitry 430 may include a single transmit chain that may be switched between radios dedicated to specific RATs. For example, a first radio may be dedicated to a first RAT, e.g., LTE, and may be in communication with a dedicated receive chain and a transmit chain shared with an additional radio, e.g., a second radio that may be dedicated to a second RAT, e.g., 5G NR, and may be in communication with a dedicated receive chain and the shared transmit chain.

[0082] The communication device 406 may also include and / or be configured for use with one or more user interface elements. The user interface elements may include any of various elements, such as display 460 (which may be a touchscreen display), a keyboard (which may be a discrete keyboard or may be implemented as part of a touchscreen display), a mouse, a microphone and / or speakers, one or more cameras, one or more buttons, and / or any of various other elements capable of providing information to a user and / or receiving or interpreting user input.

[0083] The communication device 406 may further include one or more smart cards 445 that include SIM (Subscriber Identity Module) functionality, such as one or more UICC(s) (Universal Integrated Circuit Card(s)) cards 445. Note that the term “SIM” or “SIM entity” is intended to include any of various types of SIM implementations or SIM functionality, such as the one or more UICC(s) cards 445, one or more eUICCs, one or more eSIMs, either removable or embedded, etc. In some embodiments, the UE 106 may include at least two SIMs. Each SIM may execute one or more SIM applications and / or otherwise implement SIM functionality. Thus, each SIM may be a single smart card that may be embedded, e.g., may be soldered onto a circuit board in the UE 106, or each SIM may be implemented as a removable smart card. Thus, the SIM(s) may be one or more removable smart cards (such as UICC cards, which are sometimes referred to as “SIM cards”), and / or the SIMs may be one or more embedded cards (such as embedded UICCs (eUICCs), which are sometimes referred to as “eSIMs” or “eSIM cards”). In some embodiments (such as when the SIM(s) include an eUICC), one or more of the SIM(s) may implement embedded SIM (eSIM) functionality; in such an embodiment, a single one of the SIM(s) may execute multiple SIM applications. Each of the SIMs may include components such as a processor and / or a memory; instructions for performing SIM / eSIM functionality may be stored in the memory and executed by the processor. In some embodiments, the UE 106 may include a combination of removable smart cards and fixed / non-removable smart cards (such as one or more eUICC cards that implement eSIM functionality), as desired. For example, the UE106 may comprise two embedded SIMs, two removable SIMs, or a combination of one embedded SIMs and one removable SIMs. Various other SIM configurations are also contemplated.

[0084] As noted above, in some embodiments, the UE 106 may include two or more SIMs. The inclusion of two or more SIMs in the UE 106 may allow the UE 106 to support two different telephone numbers and may allow the UE 106 to communicate on corresponding two or more respective networks. For example, a first SIM may support a first RAT such as LTE, and a second SIM support a second RAT such as 5G NR. Other implementations and RATs are of course possible. In some embodiments, when the UE 106 comprises two SIMs, the UE 106 may support Dual SIM Dual Active (DSDA) functionality. The DSDA functionality may allow the UE 106 to be simultaneously connected to two networks (and use two different RATs) at the same time, or to simultaneously maintain two connections supported by two different SIMs using the same or different RATs on the same or different networks. The DSDA functionality may also allow the UE 106 to simultaneously receive voice calls or data traffic on either phone number. In certain embodiments the voice call may be a packet switched communication. In other words, the voice call may be received using voice over LTE (VoLTE) technology and / or voice over NR (VoNR) technology. In some embodiments, the UE 106 may support Dual SIM Dual Standby (DSDS) functionality. The DSDS functionality may allow either of the two SIMs in the UE 106 to be on standby waiting for a voice call and / or data connection. In DSDS, when a call / data is established on one SIM, the other SIM is no longer active. In some embodiments, DSDx functionality (either DSDA or DSDS functionality) may be implemented with a single SIM (e.g., a eUICC) that executes multiple SIM applications for different carriers and / or RATs.

[0085] As shown, the SOC 400 may include processor(s) 402, which may execute program instructions for the communication device 406 and display circuitry 404, which may perform graphics processing and provide display signals to the display 460. The processor(s) 402 may also be coupled to memory management unit (MMU) 440, which may be configured to receive addresses from the processor(s) 402 and translate those addresses to locations in memory (e.g., memory 406, read only memory (ROM) 450, NAND flash memory 410) and / or to other circuits or devices, such as the display circuitry 404, short to medium range wireless communication circuitry 429, cellular communication circuitry 430, connector I / F 420, and / or display 460. The MMU 440 may be configured to performmemory protection and page table translation or set up. In some embodiments, the MMU 440 may be included as a portion of the processor(s) 402.

[0086] As noted above, the communication device 406 may be configured to communicate using wireless and / or wired communication circuitry. The communication device 406 may be configured to perform methods for offset estimation and correction, as further described herein.

[0087] As described herein, the communication device 406 may include hardware and software components for implementing the above features for a communication device 406 to communicate a scheduling profile for power savings to a network. The processor 402 of the communication device 406 may be configured to implement part or all of the features described herein, e.g., by executing program instructions stored on a memory medium (e.g., a non-transitory computer- readable memory medium). Alternatively (or in addition), processor 402 may be configured as a programmable hardware element, such as an FPGA (Field Programmable Gate Array), or as an ASIC (Application Specific Integrated Circuit). Alternatively (or in addition) the processor 402 of the communication device 406, in conjunction with one or more of the other components 400, 404, 406, 410, 420, 429, 430, 440, 445, 450, 460 may be configured to implement part or all of the features described herein.

[0088] In addition, as described herein, processor 402 may include one or more processing elements. Thus, processor 402 may include one or more integrated circuits (ICs) that are configured to perform the functions of processor 402. In addition, each integrated circuit may include circuitry (e.g., first circuitry, second circuitry, etc.) configured to perform the functions of processor(s) 402.

[0089] Further, as described herein, cellular communication circuitry 430 and short to medium range wireless communication circuitry 429 may each include one or more processing elements. In other words, one or more processing elements may be included in cellular communication circuitry 430 and, similarly, one or more processing elements may be included in short to medium range wireless communication circuitry 429. Thus, cellular communication circuitry 430 may include one or more integrated circuits (ICs) that are configured to perform the functions of cellular communication circuitry 430. In addition, each integrated circuit may include circuitry (e.g., first circuitry, second circuitry, etc.) configured to perform the functions of cellular communication circuitry 430. Similarly, theshort to medium range wireless communication circuitry 429 may include one or more ICs that are configured to perform the functions of short to medium range wireless communication circuitry 429. In addition, each integrated circuit may include circuitry (e.g., first circuitry, second circuitry, etc.) configured to perform the functions of short to medium range wireless communication circuitry 429.FIG. 5: Block Diagram of Cellular Communication Circuitry

[0090] FIG. 5 illustrates an example simplified block diagram of cellular communication circuitry, according to some embodiments. It is noted that the block diagram of the cellular communication circuitry of FIG. 5 is only one example of a possible cellular communication circuit. According to embodiments, cellular communication circuitry 535, which may be cellular communication circuitry 430, may be included in a communication device, such as communication device 406 described above. As noted above, communication device 406 may be a user equipment (UE) device, a mobile device or mobile station, a wireless device or wireless station, a desktop computer or computing device, a mobile computing device (e.g., a laptop, notebook, or portable computing device), a tablet and / or a combination of devices, among other devices.

[0091] The cellular communication circuitry 535 may couple (e.g., communicatively; directly or indirectly) to one or more antennas, such as antennas 435a-b and 436 as shown (in FIG. 4). In some embodiments, cellular communication circuitry 535 may include dedicated receive chains (including and / or coupled to, e.g., communicatively; directly or indirectly, dedicated processors and / or radios) for multiple RATs (e.g., a first receive chain for LTE and a second receive chain for 5G NR). For example, as shown in FIG. 5, cellular communication circuitry 535 may include a modem 510 and a modem 520. Modem 510 may be configured for communications according to a first RAT, e.g., such as LTE or LTE- A, and modem 520 may be configured for communications according to a second RAT, e.g., such as 5G NR.

[0092] As shown, modem 510 may include one or more processors 512 and a memory 516 in communication with processors 512. Modem 510 may be in communication with a radio frequency (RF) front end 530. RF front end 530 may include circuitry for transmitting and receiving radio signals. For example, RF front end 530 may include receive circuitry (RX) 532 and transmit circuitry (TX) 534. In some embodiments, receive circuitry 532 maybe in communication with downlink (DL) front end 550, which may include circuitry for receiving radio signals via antenna 335a.

[0093] Similarly, modem 520 may include one or more processors 522 and a memory 526 in communication with processors 522. Modem 520 may be in communication with an RF front end 540. RF front end 540 may include circuitry for transmitting and receiving radio signals. For example, RF front end 540 may include receive circuitry 542 and transmit circuitry 544. In some embodiments, receive circuitry 542 may be in communication with DL front end 560, which may include circuitry for receiving radio signals via antenna 335b.

[0094] In some embodiments, a switch 570 may couple transmit circuitry 534 to uplink (UL) front end 572. In addition, switch 570 may couple transmit circuitry 544 to UL front end 572. UL front end 572 may include circuitry for transmitting radio signals via antenna 336. Thus, when cellular communication circuitry 535 receives instructions to transmit according to the first RAT (e.g., as supported via modem 510), switch 570 may be switched to a first state that allows modem 510 to transmit signals according to the first RAT (e.g., via a transmit chain that includes transmit circuitry 534 and UL front end 572). Similarly, when cellular communication circuitry 535 receives instructions to transmit according to the second RAT (e.g., as supported via modem 520), switch 570 may be switched to a second state that allows modem 520 to transmit signals according to the second RAT (e.g., via a transmit chain that includes transmit circuitry 544 and UL front end 572).

[0095] In some embodiments, the cellular communication circuitry 535 may be configured to perform methods for offset estimation and correction, as further described herein.

[0096] As described herein, the modem 510 may include hardware and software components for implementing the above features or for time division multiplexing UL data for NSA NR operations, as well as the various other techniques described herein. The processors 512 may be configured to implement part or all of the features described herein, e.g., by executing program instructions stored on a memory medium (e.g., a non-transitory computer-readable memory medium). Alternatively (or in addition), processor 512 may be configured as a programmable hardware element, such as an FPGA (Field Programmable Gate Array), or as an ASIC (Application Specific Integrated Circuit). Alternatively (or in addition) the processor 512, in conjunction with one or more of the other components 530, 532, 534, 550, 570, 572, 335 and 336 may be configured to implement part or all of thefeatures described herein.

[0097] In addition, as described herein, processors 512 may include one or more processing elements. Thus, processors 512 may include one or more integrated circuits (ICs) that are configured to perform the functions of processors 512. In addition, each integrated circuit may include circuitry (e.g., first circuitry, second circuitry, etc.) configured to perform the functions of processors 512.

[0098] As described herein, the modem 520 may include hardware and software components for implementing methods for offset estimation and correction, as described herein, as well as the various other techniques described herein. The processors 522 may be configured to implement part or all of the features described herein, e.g., by executing program instructions stored on a memory medium (e.g., a non-transitory computer- readable memory medium). Alternatively (or in addition), processor 522 may be configured as a programmable hardware element, such as an FPGA (Field Programmable Gate Array), or as an ASIC (Application Specific Integrated Circuit). Alternatively (or in addition) the processor 522, in conjunction with one or more of the other components 540, 542, 544, 550, 570, 572, 335 and 336 may be configured to implement part or all of the features described herein.

[0099] In addition, as described herein, processors 522 may include one or more processing elements. Thus, processors 522 may include one or more integrated circuits (ICs) that are configured to perform the functions of processors 522. In addition, each integrated circuit may include circuitry (e.g., first circuitry, second circuitry, etc.) configured to perform the functions of processors 522.FIGs. 6A, 6B and 7: 5G Core Network Architecture - Interworking with Wi-Fi

[0100] In some embodiments, the 5G core network (CN) may be accessed via (or through) a cellular connection / interface (e.g., via a 3GPP communication architecture / protocol) and a non-cellular connection / interface (e.g., a non-3GPP access architecture / protocol such as Wi-Fi connection). FIG. 6A illustrates an example of a 5G network architecture that incorporates both 3GPP (e.g., cellular) and non-3GPP (e.g., non- cellular) access to the 5G CN and / or the internet 600, according to some embodiments. As shown, a user equipment device (e.g., such as UE 106) may access the 5G CN through botha radio access network (RAN, e.g., such as gNB 604, which may be a base station 102) and an access point, such as AP 612. The AP 612 may include a connection to the Internet 600 as well as a connection to a non-3GPP inter-working function (N3IWF) 603 network entity. The N3IWF may include a connection to a core access and mobility management function (AMF) 605 of the 5G CN. The AMF 605 may include an instance of a 5G mobility management (5G MM) function associated with the UE 106. In addition, the RAN (e.g., gNB 604) may also have a connection to the AMF 605. Thus, the 5G CN may support unified authentication over both connections as well as allow simultaneous registration for UE 106 access via both gNB 604 and AP 612. As shown, the AMF 605 may include one or more functional entities associated with the 5G CN (e.g., network slice selection function (NSSF) 620, short message service function (SMSF) 622, application function (AF) 624, unified data management (UDM) 626, policy control function (PCF) 628, and / or authentication server function (AUSF) 630). Note that these functional entities may also be supported by a session management function (SMF) 606a and an SMF 606b of the 5G CN. The AMF 605 may be connected to (or in communication with) the SMF 606a. Further, the gNB 604 may in communication with (or connected to) a user plane function (UPF) 608a that may also be communication with the SMF 606a. Similarly, the N3IWF 603 may be communicating with a UPF 608b that may also be communicating with the SMF 606b. Both UPFs may be communicating with the data network (e.g., DN 610a and 610b) and / or the Internet 600 and Internet Protocol (IP) Multimedia Subsystem / IP Multimedia Core Network Subsystem (IMS) core network 610.

[0101] FIG. 6B illustrates an example of a 5G network architecture that incorporates both dual 3GPP (e.g., LTE and 5G NR) access and non-3GPP access to the 5G CN and / or the internet 600, according to some embodiments. As shown, a user equipment device (e.g., such as UE 106) may access the 5G CN through both a radio access network (RAN, e.g., such as gNB 604 or eNB 602, which may be a base station 102) and an access point, such as AP 612. The AP 612 may include a connection to the Internet 600 as well as a connection to the N3IWF 603 network entity. The N3IWF may include a connection to the AMF 605 of the 5G CN. The AMF 605 may include an instance of the 5G MM function associated with the UE 106. In addition, the RAN (e.g., gNB 604) may also have a connection to the AMF 605. Thus, the 5G CN may support unified authentication over both connections as well as allow simultaneous registration for UE 106 access via both gNB 604 and AP 612. In addition, the 5G CN may support dual-registration of the UE on both a legacynetwork (e.g., LTE via eNB 602) and a 5G network (e.g., via gNB 604). As shown, the eNB 602 may have connections to a mobility management entity (MME) 642 and a serving gateway (SGW) 644. The MME 642 may have connections to both the SGW 644 and the AMF 605. In addition, the SGW 644 may have connections to both the SMF 606a and the UPF 608a. As shown, the AMF 605 may include one or more functional entities associated with the 5G CN (e.g., NSSF 620, SMSF 622, AF 624, UDM 626, PCF 628, and / or AUSF 630). Note that UDM 626 may also include a home subscriber server (HSS) function and the PCF may also include a policy and charging rules function (PCRF). Note further that these functional entities may also be supported by the SMF606a and the SMF 606b of the 5G CN. The AMF 605 may be connected to (or in communication with) the SMF 606a. Further, the gNB 604 may in communication with (or connected to) the UPF 608a that may also be communication with the SMF 606a. Similarly, the N3IWF 603 may be communicating with a UPF 608b that may also be communicating with the SMF 606b. Both UPFs may be communicating with the data network (e.g., DN 610a and 610b) and / or the Internet 600 and IMS core network 610.

[0102] Note that in various embodiments, one or more of the above-described network entities may be configured to perform methods for offset estimation and correction, as further described herein.

[0103] FIG. 7 illustrates an example of a baseband processor architecture for a UE (e.g., such as UE 106), according to some embodiments. The baseband processor architecture 700 described in FIG. 7 may be implemented on one or more radios (e.g., radios 429 and / or 430 described above) or modems (e.g., modems 510 and / or 520) as described above. As shown, the non-access stratum (NAS) 710 may include a 5G NAS 720 and a legacy NAS 750. The legacy NAS 750 may include a communication connection with a legacy access stratum (AS) 770. The 5G NAS 720 may include communication connections with both a 5G AS 740 and a non-3GPP AS 730 and Wi-Fi AS 732. The 5G NAS 720 may include functional entities associated with both access stratums. Thus, the 5G NAS 720 may include multiple 5G MM entities 726 and 728 and 5G session management (SM) entities 722 and 724. The legacy NAS 750 may include functional entities such as short message service (SMS) entity 752, evolved packet system (EPS) session management (ESM) entity 754, session management (SM) entity 756, EPS mobility management (EMM) entity 758, and mobility management (MM) / GPRS mobility management (GMM) entity 760. In addition, the legacy AS 770 may include functional entities such as LTE AS 772, UMTS AS 774,and / or GSM / GPRS AS 776.

[0104] Thus, the baseband processor architecture 700 allows for a common 5G-NAS for both 5G cellular and non-cellular (e.g., non-3GPP access). The baseband processor architecture 700 can be in communication with one or more UICC(s) 745. Note that as shown, the 5G MM may maintain individual connection management and registration management state machines for each connection. Additionally, a device (e.g., UE 106) may register to a single PLMN (e.g., 5G CN) using 5G cellular access as well as non-cellular access. Further, it may be possible for the device to be in a connected state in one access and an idle state in another access and vice versa. Finally, there may be common 5G-MM procedures (e.g., registration, de-registration, identification, authentication, as so forth) for both accesses.

[0105] Note that in various embodiments, one or more of the above-described functional entities of the 5G NAS and / or 5G AS may be configured to methods for offset estimation and correction as further described herein.

[0106] FIG. 8 illustrates example components of a device 800 in accordance with some embodiments. In some embodiments, the device 800 may include application circuitry 802, baseband circuitry 804, Radio Frequency (RF) circuitry 806, front-end module (FEM) circuitry 808, one or more antennas 810, and power management circuitry (PMC) 812 coupled together at least as shown. The components of the illustrated device 800 may be included in a UE or a RAN node. In some embodiments, the device 800 may include less elements (e.g., a RAN node may not utilize application circuitry 802, and instead include a processor / controller to process IP data received from an EPC). In some embodiments, the device 800 may include additional elements such as, for example, memory / storage, display, camera, sensor, or input / output (I / O) interface. In other embodiments, the components described below may be included in more than one device (e.g., said circuitries may be separately included in more than one device for Cloud-RAN (C-RAN) implementations).

[0107] The application circuitry 802 may include one or more application processors. For example, the application circuitry 802 may include circuitry such as, but not limited to, one or more single-core or multi-core processors. The processor(s) may include any combination of general-purpose processors and dedicated processors (e.g., graphics processors, application processors, etc.). The processors may be coupled with or may include memory / storage and may be configured to execute instructions stored in the memory / storageto enable various applications or operating systems to run on the device 800. In some embodiments, processors of application circuitry 802 may process IP data packets received from an EPC.

[0108] The baseband circuitry 804 may include circuitry such as, but not limited to, one or more single-core or multi-core processors. The baseband circuitry 804 may include one or more baseband processors or control logic to process baseband signals received from a receive signal path of the RF circuitry 806 and to generate baseband signals for a transmit signal path of the RF circuitry 806. Baseband processing circuity 804 may interface with the application circuitry 802 for generation and processing of the baseband signals and for controlling operations of the RF circuitry 806. For example, in some embodiments, the baseband circuitry 804 may include a third generation (3G) baseband processor 804A, a fourth generation (4G) baseband processor 804B, a fifth generation (5G) baseband processor 804C, or other baseband processor(s) 804D for other existing generations, generations in development or to be developed in the future (e.g., second generation (2G), sixth generation (6G), etc.). The baseband circuitry 804 (e.g., one or more of baseband processors 804A-D) may handle various radio control functions that enable communication with one or more radio networks via the RF circuitry 806. In other embodiments, some or all of the functionality of baseband processors 804A-D may be included in modules stored in the memory 804G and executed via a Central Processing Unit (CPU) 804E. The radio control functions may include, but are not limited to, signal modulation / demodulation, encoding / decoding, radio frequency shifting, etc. In some embodiments, modulation / demodulation circuitry of the baseband circuitry 804 may include Fast-Fourier Transform (FFT), precoding, or constellation mapping / demapping functionality. In some embodiments, encoding / decoding circuitry of the baseband circuitry 804 may include convolution, tail-biting convolution, turbo, Viterbi, or Low Density Parity Check (LDPC) encoder / decoder functionality. In some embodiments baseband circuitry 804 may perform functions corresponding to a received waveform having data modulated according to Orthogonal frequency division multiplexing (OFDM). OFDM is a modulation technique that is widely used in wireless communications, e.g., OFDM is utilized in 5G NR and Wi-Fi. OFDM is a multicarrier modulation scheme that utilizes subcarriers. In OFDM data to be transmitted is divided up into streams and each stream is modulated onto one of multiple subcarriers. Embodiments of modulation / demodulation and encoder / decoder functionality are not limited to these examples and may include other suitable functionality in otherembodiments.

[0109] In some embodiments, the baseband circuitry 804 may include one or more audio digital signal processor(s) (DSP) 804F. The audio DSP(s) 804F may be include elements for compression / decompression and echo cancellation and may include other suitable processing elements in other embodiments. Components of the baseband circuitry may be suitably combined in a single chip, a single chipset, or disposed on a same circuit board in some embodiments. In some embodiments, some or all of the constituent components of the baseband circuitry 804 and the application circuitry 802 may be implemented together such as, for example, on a system on a chip (SOC).

[0110] In some embodiments, the baseband circuitry 804 may provide for communication compatible with one or more radio technologies. For example, in some embodiments, the baseband circuitry 804 may support communication with an evolved universal terrestrial radio access network (EUTRAN) or other wireless metropolitan area networks (WMAN), a wireless local area network (WLAN), a wireless personal area network (WPAN). Embodiments in which the baseband circuitry 804 is configured to support radio communications of more than one wireless protocol may be referred to as multi-mode baseband circuitry.

[0111] RF circuitry 806 may enable communication with wireless networks using modulated electromagnetic radiation through a non-solid medium. In various embodiments, the RF circuitry 806 may include switches, filters, amplifiers, etc. to facilitate the communication with the wireless network. RF circuitry 806 may include a receive signal path which may include circuitry to down-convert RF signals received from the FEM circuitry 808 and provide baseband signals to the baseband circuitry 804. RF circuitry 806 may also include a transmit signal path which may include circuitry to up-convert baseband signals provided by the baseband circuitry 804 and provide RF output signals to the FEM circuitry 808 for transmission.

[0112] In some embodiments, the receive signal path of the RF circuitry 806 may include mixer circuitry 806a, amplifier circuitry 806b and filter circuitry 806c. Tn some embodiments, the transmit signal path of the RF circuitry 806 may include filter circuitry 806c and mixer circuitry 806a. RF circuitry 806 may also include synthesizer circuitry 806d for synthesizing a frequency for use by the mixer circuitry 806a of the receive signal path and the transmit signal path. In some embodiments, the mixer circuitry 806a of the receive signalpath may be configured to down-convert RF signals received from the FEM circuitry 808 based on the synthesized frequency provided by synthesizer circuitry 806d. The amplifier circuitry 806b may be configured to amplify the down-converted signals and the filter circuitry 806c may be a low-pass filter (LPF) or band-pass filter (BPF) configured to remove unwanted signals from the down-converted signals to generate output baseband signals. Output baseband signals may be provided to the baseband circuitry 804 for further processing. In some embodiments, the output baseband signals may be zero-frequency baseband signals, although this is not a requirement. In some embodiments, mixer circuitry 806a of the receive signal path may comprise passive mixers, although the scope of the embodiments is not limited in this respect.

[0113] In some embodiments, the mixer circuitry 806a of the transmit signal path may be configured to up-convert input baseband signals based on the synthesized frequency provided by the synthesizer circuitry 806d to generate RF output signals for the FEM circuitry 808. The baseband signals may be provided by the baseband circuitry 804 and may be filtered by filter circuitry 806c.

[0114] In some embodiments, the mixer circuitry 806a of the receive signal path and the mixer circuitry 806a of the transmit signal path may include two or more mixers and may be arranged for quadrature downconversion and upconversion, respectively. In some embodiments, the mixer circuitry 806a of the receive signal path and the mixer circuitry 806a of the transmit signal path may include two or more mixers and may be arranged for image rejection (e.g., Hartley image rejection). In some embodiments, the mixer circuitry 806a of the receive signal path and the mixer circuitry 806a may be arranged for direct downconversion and direct upconversion, respectively. In some embodiments, the mixer circuitry 806a of the receive signal path and the mixer circuitry 806a of the transmit signal path may be configured for super-heterodyne operation.

[0115] In some embodiments, the output baseband signals and the input baseband signals may be analog baseband signals, although the scope of the embodiments is not limited in this respect. In some alternate embodiments, the output baseband signals and the input baseband signals may be digital baseband signals. In these alternate embodiments, the RF circuitry 806 may include analog-to-digital converter (ADC) and digital-to-analog converter (DAC) circuitry and the baseband circuitry 804 may include a digital baseband interface to communicate with the RF circuitry 806.

[0116] In some dual-mode embodiments, a separate radio IC circuitry may be provided for processing signals for each spectrum, although the scope of the embodiments is not limited in this respect.

[0117] In some embodiments, the synthesizer circuitry 806d may be a fractional-N synthesizer or a fractional N / N+l synthesizer, although the scope of the embodiments is not limited in this respect as other types of frequency synthesizers may be suitable. For example, synthesizer circuitry 806d may be a delta-sigma synthesizer, a frequency multiplier, or a synthesizer comprising a phase-locked loop with a frequency divider.

[0118] The synthesizer circuitry 806d may be configured to synthesize an output frequency for use by the mixer circuitry 806a of the RF circuitry 806 based on a frequency input and a divider control input. In some embodiments, the synthesizer circuitry 806d may be a fractional N / N+l synthesizer.

[0119] In some embodiments, frequency input may be provided by a voltage controlled oscillator (VCO), although that is not a requirement. Divider control input may be provided by either the baseband circuitry 804 or the applications processor 802 depending on the desired output frequency. In some embodiments, a divider control input (e.g., N) may be determined from a look-up table based on a channel indicated by the applications processor 802.

[0120] Synthesizer circuitry 806d of the RF circuitry 806 may include a divider, a delay- locked loop (DLL), a multiplexer and a phase accumulator. In some embodiments, the divider may be a dual modulus divider (DMD) and the phase accumulator may be a digital phase accumulator (DPA). In some embodiments, the DMD may be configured to divide the input signal by either N or N+l (e.g., based on a carry out) to provide a fractional division ratio. In some example embodiments, the DLL may include a set of cascaded, tunable, delay elements, a phase detector, a charge pump and a D-type flip-flop. In these embodiments, the delay elements may be configured to break a VCO period up into Nd equal packets of phase, where Nd is the number of delay elements in the delay line. In this way, the DLL provides negative feedback to help ensure that the total delay through the delay line is one VCO cycle.

[0121] In some embodiments, synthesizer circuitry 806d may be configured to generate a carrier frequency as the output frequency, while in other embodiments, the output frequency may be a multiple of the carrier frequency (e.g., twice the carrier frequency, four times the carrier frequency) and used in conjunction with quadrature generator and divider circuitry togenerate multiple signals at the carrier frequency with multiple different phases with respect to each other. In some embodiments, the output frequency may be a LO frequency (fLO). In some embodiments, the RF circuitry 806 may include an IQ / polar converter.

[0122] FEM circuitry 808 may include a receive signal path which may include circuitry configured to operate on RF signals received from one or more antennas 810, amplify the received signals and provide the amplified versions of the received signals to the RF circuitry 806 for further processing. FEM circuitry 808 may also include a transmit signal path which may include circuitry configured to amplify signals for transmission provided by the RF circuitry 806 for transmission by one or more of the one or more antennas 810. In various embodiments, the amplification through the transmit or receive signal paths may be done solely in the RF circuitry 806, solely in the FEM 808, or in both the RF circuitry 806 and the FEM 808.

[0123] In some embodiments, the FEM circuitry 808 may include a TX / RX switch to switch between transmit mode and receive mode operation. The FEM circuitry may include a receive signal path and a transmit signal path. The receive signal path of the FEM circuitry may include an LN A to amplify received RF signals and provide the amplified received RF signals as an output (e.g., to the RF circuitry 806). The transmit signal path of the FEM circuitry 808 may include a power amplifier (PA) to amplify input RF signals (e.g., provided by RF circuitry 806), and one or more filters to generate RF signals for subsequent transmission (e.g., by one or more of the one or more antennas 810).

[0124] In some embodiments, the PMC 812 may manage power provided to the baseband circuitry 804. In particular, the PMC 812 may control power-source selection, voltage scaling, battery charging, or DC-to-DC conversion. The PMC 812 may often be included when the device 800 is capable of being powered by a battery, for example, when the device is included in a UE. The PMC 812 may increase the power conversion efficiency while providing desirable implementation size and heat dissipation characteristics.

[0125] While FIG. 8 shows the PMC 812 coupled only with the baseband circuitry 804. However, in other embodiments, the PMC 812 may be additionally or alternatively coupled with, and perform similar power management operations for, other components such as, but not limited to, application circuitry 802, RF circuitry 806, or FEM 808.

[0126] In some embodiments, the PMC 812 may control, or otherwise be part of, various power saving mechanisms of the device 800. For example, if the device 800 is in anRRC_Connected state, where it is still connected to the RAN node as it expects to receive traffic shortly, then it may enter a state known as Discontinuous Reception Mode (DRX) after a period of inactivity. During this state, the device 800 may power down for brief intervals of time and thus save power.

[0127] If there is no data traffic activity for an extended period of time, then the device 800 may transition off to an RRC_Idle state, where it disconnects from the network and does not perform operations such as channel quality feedback, handover, etc. The device 800 goes into a very low power state and it performs paging where again it periodically wakes up to listen to the network and then powers down again. The device 800 may not receive data in this state, in order to receive data, it can transition back to RRC_Connected state.

[0128] An additional power saving mode may allow a device to be unavailable to the network for periods longer than a paging interval (ranging from seconds to a few hours). During this time, the device is totally unreachable to the network and may power down completely. Any data sent during this time incurs a large delay and it is assumed the delay is acceptable.

[0129] Processors of the application circuitry 802 and processors of the baseband circuitry 804 may be used to execute elements of one or more instances of a protocol stack. For example, processors of the baseband circuitry 804, alone or in combination, may be used to execute Layer 3, Layer 2, or Layer 1 functionality, while processors of the application circuitry 804 may utilize data (e.g., packet data) received from these layers and further execute Layer 4 functionality (e.g., transmission communication protocol (TCP) and user datagram protocol (UDP) layers). As referred to herein, Layer 3 may comprise a radio resource control (RRC) layer, described in further detail below. As referred to herein, Layer 2 may comprise a medium access control (MAC) layer, a radio link control (RLC) layer, and a packet data convergence protocol (PDCP) layer, described in further detail below. As referred to herein, Layer 1 may comprise a physical (PHY) layer of a UE / RAN node, described in further detail below.

[0130] FIG. 9 illustrates example interfaces of baseband circuitry in accordance with some embodiments. As discussed above, the baseband circuitry 804 of FIG. 8 may comprise processors 804A-804E and a memory 804G utilized by said processors. Each of the processors 804A-804E may include a memory interface, 904A-904E, respectively, to send / receive data to / from the memory 804G.

[0131] The baseband circuitry 804 may further include one or more interfaces to communicatively couple to other circuitries / de vices, such as a memory interface 912 (e.g., an interface to send / receive data to / from memory e8emal to the baseband circuitry 804), an application circuitry interface 914 (e.g., an interface to send / receive data to / from the application circuitry 802 of FIG. 8), an RF circuitry interface 916 (e.g., an interface to send / receive data to / from RF circuitry 806 of FIG. 8), a wireless hardware connectivity interface 918 (e.g., an interface to send / receive data to / from Near Field Communication (NFC) components, Bluetooth® components (e.g., Bluetooth® Low Energy), Wi-Fi® components, and other communication components), and a power management interface 920 (e.g., an interface to send / receive power or control signals to / from the PMC 812.

[0132] FIG. 10 is an illustration of a control plane protocol stack in accordance with some embodiments. In one embodiment, a control plane 1000 may be a communications protocol stack between one or more UEs such as, for example, UE 801 (or alternatively, the UE 802), and / or one or more RAN nodes 811 (or alternatively, the RAN node 812), and a mobility management entity (MME) 821.

[0133] The PHY layer 1001 may transmit or receive information used by the MAC layer 1002 over one or more air interfaces. The PHY layer 1001 may further perform link adaptation or adaptive modulation and coding (AMC), power control, cell search (e.g., for initial synchronization and handover purposes), and other measurements used by higher layers, such as the RRC layer 1005. The PHY layer 1001 may still further perform error detection on the transport channels, forward error correction (FEC) coding / decoding of the transport channels, modulation / demodulation of physical channels, interleaving, rate matching, mapping onto physical channels, and Multiple Input Multiple Output (MIMO) antenna processing.

[0134] The MAC layer 1002 may perform mapping between logical channels and transport channels, multiplexing of MAC service data units (SDUs) from one or more logical channels onto transport blocks (TB) to be delivered to PHY via transport channels, demultiplexing MAC SDUs to one or more logical channels from transport blocks (TB) delivered from the PHY via transport channels, multiplexing MAC SDUs onto TBs, scheduling information reporting, error correction through hybrid automatic repeat request (HARQ), and logical channel prioritization.

[0135] The REC layer 1003 may operate in a plurality of modes of operation, including:Transparent Mode (TM), Unacknowledged Mode (UM), and Acknowledged Mode (AM). The RLC layer 1003 may execute transfer of upper layer protocol data units (PDUs), error correction through automatic repeat request (ARQ) for AM data transfers, and concatenation, segmentation and reassembly of RLC SDUs for UM and AM data transfers. The RLC layer 1003 may also execute re-segmentation of RLC data PDUs for AM data transfers, reorder RLC data PDUs for UM and AM data transfers, detect duplicate data for UM and AM data transfers, discard RLC SDUs for UM and AM data transfers, detect protocol errors for AM data transfers, and perform RLC re-establishment.

[0136] The PDCP layer 1004 may execute header compression and decompression of IP data, maintain PDCP Sequence Numbers (SNs), perform in-sequence delivery of upper layer PDUs at re-establishment of lower layers, eliminate duplicates of lower layer SDUs at reestablishment of lower layers for radio bearers mapped on RLC AM, cipher and decipher control plane data, perform integrity protection and integrity verification of control plane data, control timer-based discard of data, and perform security operations (e.g., ciphering, deciphering, integrity protection, integrity verification, etc.).

[0137] The main services and functions of the RRC layer 1005 may include broadcast of system information (e.g., included in Master Information Blocks (MIBs) or System Information Blocks (SIBs) related to the non-access stratum (NAS)), broadcast of system information related to the access stratum (AS), paging, establishment, maintenance and release of an RRC connection between the UE and E-UTRAN (e.g., RRC connection paging, RRC connection establishment, RRC connection modification, and RRC connection release), establishment, configuration, maintenance and release of point to point Radio Bearers, security functions including key management, inter radio access technology (RAT) mobility, and measurement configuration for UE measurement reporting. Said MIBs and SIBs may comprise one or more information elements (IES), which may each comprise individual data fields or data structures.

[0138] In one example, a UE (e.g., UE 106A-N) and a RAN node (e.g., base station 102) 811may utilize a Uu interface (e.g., an LTE-Uu interface) to exchange control plane data via a protocol stack comprising the PHY layer 1001, the MAC layer 1002, the RLC layer 1003, the PDCP layer 1004, and the RRC layer 1005.

[0139] The non-access stratum (NAS) protocols 1006 form the highest stratum of the control plane between the UE (e.g., UE 106A-N) 801 and an MME 821. The NAS protocols1006 support the mobility of the UE (e.g., UE 106A-N) 801and the session management procedures to establish and maintain IP connectivity between the UE (e.g., UE 106A-N) 801and a P-GW.

[0140] The S 1 Application Protocol (S 1-AP) layer 1015 may support the functions of the SI interface and comprise Elementary Procedures (EPs). An EP is a unit of interaction between a RAN node (e.g., base station 102) 81 1 and the CN. The SI -AP layer 1015 services may comprise two groups: UE-associated services and non UE-associated services. These services perform functions including, but not limited to: E-UTRAN Radio Access Bearer (E- RAB) management, UE capability indication, mobility, NAS signaling transport, RAN Information Management (RIM), and configuration transfer.

[0141] The Stream Control Transmission Protocol (SCTP) layer (alternatively referred to as the SCTP / IP layer) 1014 may ensure reliable delivery of signaling messages between the RAN node (e.g., base station 102) 811 and a MME 821 based, in part, on the IP protocol, supported by the IP layer 1013. The L2 layer 1012 and the LI layer 1011 may refer to communication links (e.g., wired or wireless) used by the RAN node (e.g., base station 102) and the MME to exchange information.

[0142] The RAN node (e.g., base station 102) 811 and the MME 821may utilize an Sl- MME interface to exchange control plane data via a protocol stack comprising the LI layer 1011, the L2 layer 1012, the IP layer 1013, the SCTP layer 1014, and the Sl-AP layer 1015.FIGs. 11, 12 and 13: Reference Signals

[0143] As described above, the baseband circuitry 804 may handle various radio control functions that enable communication with one or more radio networks via a wireless link. For example, the baseband circuitry 804 may handle signal modulation / demodulation, encoding / decoding, radio frequency shifting, etc. Time offsets (TO) (i.e., a delay in a received signal) and Frequency offsets (FO) (i.e., a difference between a nominal and actual carrier frequency of a received signal) are inherently present in the wireless links. The reasons for these offsets vary and may be due to one or more of clock mismatches, wireless channel quality, and mobility of a transmitter, receiver, or both a transmitter and a receiver. Time and Frequency offsets are present in both terrestrial and non-terrestrial (satellite) networks. In OFDM systems, carrier frequency offset (CFO) may occur due to differencesin frequencies of the transmitter oscillator and the receiver oscillator. CFO can cause subcarriers to drift away from their intended positions, leading to inter-symbol interference. CFO may be described as including two components: Integer Frequency Offset (IFO) which represents the whole number of subcarrier shifts; and Fractional Frequency Offset (FFO) which represents the fractional part of the subcarrier shift.

[0144] Radio networks transmit reference signals specifically designed to compensate for TO and FO. In 5G NR, a network or base station transmits a so-called tracking reference signal (TRS) which may be used for TO and FO estimation. In Wi-Fi, an access point transmits a preamble containing training sequences which may be used for TO and FO estimation. In 5G NR, a non-zero power (NZP) channel state information reference signal (CSI-RS) includes a TRS which may be measured by a UE in order to estimate and compensate for TO and FO. That is, for example, a base station may transmit a NZP CSI- RS (e.g., periodically) including a TRS to a UE and the UE may perform measurements on the TRS to estimate TO and FO. In Wi-Fi, a legacy preamble includes a short training field (STF) and a long training field (LTF). Each of the STF and LTF include repeated patterns of symbols with good correlation properties. The STF is suitable for coarse TO and FO estimation. The LTF is suitable for fine TO and FO estimation. It should be noted that in Wi-Fi, a high-efficiency (HE) preamble may be used in addition to the legacy preamble.

[0145] It should be noted that coarse and fine frequency offset estimation in OFDM may rely on correlations of the reference signals. Further, fractional and integer frequency offset estimation may rely on correlation and FFT operations. TO estimation may be based on the location of correlation peaks. For each of coarse and fine frequency offset estimation, fractional and integer frequency offset estimation, and TO estimation, estimation performance depends on the time-domain length of the reference waveform. That is, in general, the shorter the time-domain length of the waveform, the less accurate an algorithm for TO and FO estimation becomes, particularly for low signal-to-noise (SNR) cases. According to the techniques described herein, reference signals specifically designed to compensate for TO and FO may be combined with additional types of reference signals, for example, additional reference signals within the same transmission cycle, to generate reference waveforms with increased time-domain length. Reference waveforms with increased time-domain may be used by a UE for TO and / or FO. The techniques described herein may be particularly useful for low signal-to-noise cases, which may be present, for example, in non-terrestrial (satellite) communication networks.

[0146] As described above, in 5G NR, CSI-RS includes a TRS. A CSI-RS may be periodic / semi-persistent or aperiodic. Configuration information may indicate whether the CSI-RS is periodic / semi-persistent or aperiodic and in the case of a periodic configuration information may indicate the period in terms of number of slots. Further, configuration information may indicate information about CSI-RS resources. That is, configuration information may indicate the resource elements of a CSI-RS according to a number of antenna port numbers, a density (number of resource elements allocated per port), multiplexing type, and locations within a slot (i.e., frequency and time domain locations). A resource element is the smallest unit of time-frequency resources in the OFDM resource grid. In the case of multiple antenna ports, the locations of resource elements in a resource block are provided for each respective antenna port. In some examples, a CSI-RS may correspond to up 32 different antenna ports (e.g., 1, 2, 4, 8, 16, 24, or 32).

[0147] FIGs. 11 and 12 illustrate an example of resource grids including reference signals. In the examples of FIGs. 11 and 12, subcarrier frequency bands are represented by vertical locations and time domain locations are represented by horizontal locations. Thus, the resource grids in FIGs. 11 and 12 illustrate frequency and time domain locations of resources corresponding to reference signals. In 5G NR, Physical Data Share Channel (PDSCH) is a downlink physical channel that delivers user data from a gNB to UE. The resource grid in FIG. 11 may correspond to a PDSCH. Further, 5G NR provides where a resource block (RB) includes 12 subcarriers and each frequency and time domain location is referred to as a resource element. In Wi-Fi, a physical layer protocol data unit (PPDU), including a preamble and data fields is used for downlink transmissions. The resource grid in FIG. 12 may correspond to a PPDU. Further, Wi-Fi provides where each frequency and time domain location is referred to as a resource unit. The techniques described herein, are generally applicable regardless of particular resource grid implementations. That is, the techniques described herein are generally applicable to various symbol and subcarrier configurations.

[0148] As described above, in 5G NR, a CSI-RS includes a TSR. FIG. 11 illustrates an example where a first reference signal includes a TRS and further provides the frequency and time domain locations of resource elements of a TRS within a PDSCH. In 5G NR, a TRS may use a single port with a density of 3 resource elements per resource block. It should be noted that the particular location of the resource elements of a TRS may be configurable. 5G NR further provides where a Demodulation Reference Signal (DMRS)is transmitted in a PDSCH. The DMRS is used for channel estimation as part of coherent demodulation of PDSCH. That is, a DMRS is not specifically designed for TO and FO estimation and is a distinct type of reference signal from a TRS. In 5G NR, for every PDSCH, it is mandatory to have at least one OFDM symbol of DMRS. Further, a PDSCH may be configured to have additional OFMD symbols of a DMRS (e.g., one to three additional symbols).

[0149] FIG. 11 further illustrates an example where a second reference signal includes a DMRS and further provides the frequency and time domain locations of resource elements of a DMRS with a PDSCH. It should be noted that the particular location of the resource elements of a TRS may be configurable. As illustrated in FIG. 11, resource elements for both the TRS and the DMRS are included in the resource grid. That is, during transmission time of the first and second slot in FIG. 11, which may be an example of a transmission cycle, a first and a second reference signal are transmitted. As described in further detail below, a first and a second reference signal within the same transmission cycle may be used to generate a reference waveform which may be used for TO and / or FO. It should be noted that in other examples, two, or more, types of reference signals may be used to generate a reference waveform. For example, in 5G NR, in addition to a TRS and a DMRS, the following reference signals are defined: Phase Tracking Reference Signal (PTRS), PSS (Primary Synchronization Signal), SSS (Secondary Synchronization Signal), according to the techniques herein any combination of these signals and other reference signals in 5G NR may be used to generate a reference waveform.

[0150] As described above, in Wi-Fi, a PPDU includes a preamble field and a data field. Parts of the preamble can be transmitted over the whole channel. Wi-Fi further provides where pilot symbols are included in the data field in order to track frequency, phase, and amplitude variations over the transmission. For example, the pilots can be located in every OFDM data symbols at fixed subcarrier locations. FIG. 12 illustrates an example where pilot symbols are included with data in the resource grid. Thus, as illustrated in FIG. 12, resource units for both the preamble and the pilot symbols are included in the resource grid. That is, during transmission time of the frame including a preamble field and a data field in FIG. 12, which may be an example of a transmission cycle, a first and a second reference signal are transmitted. As described in further detail below, reference signals within the same transmission cycle may be combined to generate a reference waveform which may be used for TO and / or FO. According to the techniquesherein, any combination of different types of signals within a transmission cycle may be used to generate a reference. That is, the techniques described herein are generally applicable to wireless communications. FIG. 13 illustrates an example where N reference signals are included in a transmission cycle. FIG. 13 may correspond to various wireless communication systems, include for example, satellite communication systems. According to the techniques herein, any combination of the N reference signals may be used to generate a reference waveform.FIGs. 14-17B: Generating Reference Waveforms

[0151] FIG. 14 illustrates an example of a simplified wireless communication system which may generate a reference waveform and use the generated reference waveform for TO and / or FO estimation and correction according to the techniques herein. The wireless communication system may correspond to any of the wireless communications systems described herein, including for example, a 5G NR communication system and / or a Wi-Fi communication system. Further, the wireless communication system in FIG. 14 may correspond to any terrestrial and non-terres trial communication system, including communication systems in development or to be developed in the future. The communications system in FIG. 14 includes a transmission device 1410 and receiver device 1450 which communicate over a wireless channel. For example, transmission device 1410 may include a network, a BS, or an access point and receiver device 1450 may include a UE, as described above. It should be noted that transmission device 1410 and receiver device 1450 may include additional components described above, for example, components described above with respect to FIGs. 7-9.

[0152] Transmission device 1410 includes modulation unit 1412, resource mapping unit 1414, and OFDM IFFT unit 1416. As illustrated in FIG. 14, modulation unit 1412 receives data. Data may include data to be transmitted to receiver device 1450. For example, data may include bits of digital data corresponding voice, SMS and / or data services. Modulation unit 1412 modulates the received data according to a modulation technique. For example, modulation unit 1412 may modulate data to according a digital modulation technique, for example, QPSK (Quadrature Phase Shift Keying), BPSK (Binary Phase-shift keying), QAM (quadrature amplitude modulation), or the like, to generate symbols. As described above, resource grid includes frequency and time domain locationsof resources corresponding to data and reference signals. Resource mapping unit 1414 receives symbols corresponding to reference signals, reference signal 1 (RSI) and reference signal 2 (RS2), in the example of FIG. 14, and symbols corresponding to data and maps the symbols to a resource grid. For example, in the case of 5G NR, resource mapping unit 1414 may map reference signals and data to a resource grid corresponding to a PDSCH and in the case of Wi-Fi, resource mapping unit 1414 may map reference signals (including a preamble and pilot symbols) and data to a resource grid corresponding to a PPDU. OFDM 1FFT unit 1416 performs an 1FFT operation in order to output the symbol representations in the time domain as a serial stream for transmission over the wireless channel. That is, a serial stream may be upconverted to a carrier frequency for transmission over the wireless channel. This transmission and received versions thereof may be referred to as a waveform.

[0153] Receiver device 1450 receives the waveform including the data and the reference signals over the wireless channel. Receiver device 1450 further generates a reference waveform and performs time and / or frequency offset estimation and correction by comparing the received waveform and the generated reference waveform. Receiver device 1450 includes resource mapping unit 1414 and OFDM IFFT unit 1416, which may operate as described above with respect to transmission device 1410. Receiver device 1450 further includes offset estimation unit 1452, offset correction unit 1454, OFDM FFT unit 1456, demapper unit 1458, and demodulation / decoding unit 1460. Each of OFDM FFT unit 1456, demapper unit 1458, and demodulation / decoding unit 1460 perform reciprocal functions to OFDM IFFT unit 1416, resource mapping unit 1414, and modulation unit 1412 of transmission device 1410 such data is recovered. As described in further detail below, offset estimation unit 1452 estimates TO and FO and offset correction unit 1454 applies a correction based on the estimated TO and FO.

[0154] As illustrated in FIG. 14, resource mapping unit 1414 in receiver device 1450 receives data symbols corresponding to reference signal 1 and reference signal 2 and maps the reference signals to a resource grid. That is, the generated waveform does not include the data symbols. That is, the data to be received is unknown prior to reception, whereas receiver device 1450 knows the symbols of the reference signals and how the symbols are mapped to a resource grid prior to reception. For example, as described above, configuration information indicates how defined reference signals are to be included in a DL transmission.

[0155] As described above, for each of coarse and fine frequency offset estimation, fractional and integer frequency offset estimation, and TO estimation, estimation performance depends on the time-domain length of the reference waveform. As further described above, according to the techniques described herein, reference signals specifically designed to compensate for TO and FO may be combined with additional types of reference signals, for example, additional reference signals within the same transmission cycle, to generate reference waveforms with increased time-domain length. That is, according to the techniques herein, receiver device 1450 may use any combination of reference signals to generate a reference waveform. For example, in the case of 5G NR, receiver device 1450 may select any combination of a TRS, a DMRS, a PTRS, a PSS, a SSS and other reference signals to generate a reference waveform. In the case of Wi-Fi, receiver device 1450 may select a preamble and pilot symbols to generate a reference waveform. In some cases, reference signals which may be selected may be based on whether the reference signals are transmitted within a specified time period. For example, a specified time period may be in the order to 5 to 10 ms. In general, a specified time period may be set based on an assumption that within the specified time period drift, for example, clock drift, is relatively small.

[0156] FIG. 15 illustrates an example of a reference waveform in the time domain. The example reference waveform in FIG. 15 corresponds to a preamble sequence. That is, the reference waveform in FIG. 15 is generated using a single reference signal. FIG. 16 illustrates an example of a reference waveform in the time domain. The example reference waveform in FIG. 16 corresponds to a preamble sequence and pilot symbols. That is, the reference waveform in FIG. 16 is generated using a first selected reference signal and a second reference signal. As illustrated in FIG. 15 and FIG. 16, the reference waveform in FIG. 16 includes more time domain samples than the reference waveform in FIG. 15. Thus, each of coarse and fine frequency offset estimation, fractional and integer frequency offset estimation, and TO estimation, estimation performance may be improved by using the reference waveform in FIG. 16 compared to the reference waveform in FIG 15. In some cases, the reference waveform in FIG. 16 may have gains in the order of IdB (SNR) in TO and FO estimation performance.

[0157] FIGs. 17A-17B illustrate correlating a reference waveform and a received waveform for TO and FO estimation. FIG. 17A-17B illustrate how TO and FO estimation performance may be improved by using a reference waveform including a first referencesignal and a second reference, according to the techniques herein. In each of FIG. 17A and 17B, a reference waveform is generated and a corresponding waveform is received. Correlation is performed by sliding the generated reference waveform over the received waveform and determining a correlation peak. That is, in the example of FIGS. 17A and 17B, the reference waveform may be iteratively slid such that SO of the reference waveform is aligned with each of sample SO to SN of the received waveform. At each iteration, the waveforms may be summed. In some cases, the summed waveforms may be referred to as correlation waveforms. The iteration with the maximum sum provides the correlation peak, which may indicate the offset. For example, in the example of FIGs. 17A and 17B, the received waveform is offset by two samples compared to the generated waveform. Thus, when SO of the generated reference waveform is aligned with S2 of the received waveform, the sum of the waves is maximized.

[0158] As illustrated, similar to the example in FIG. 15, the reference waveform in FIG. 17A includes only the preamble sequence. Further, similar to the example in FIG. 16, the reference waveform in FIG. 17B includes the preamble sequence and pilot symbols. As such, the correlation peak in FIG. 17B is greater than the correlation peak in FIG. 17A. Thus, using the reference waveform in FIG. 17B provides a greater potential for more distinct correlation peak measurements which improves offset estimation. It should be noted that FIGS. 17A- 17B provide a simplified example of correlating a reference waveform and a received waveform for illustrative purposes. The techniques described herein may be generally applicable. For example, in some cases, an FFT may be performed on the correlation waveforms, to find correlation peaks in frequency domain. Different time shifted versions of the correlation waveform can be used to find the highest peak in frequency domain, indicating the estimated time and frequency offset estimate values. In other cases, the time domain correlation peaks may be used to estimate the timing offset. Thus, offset estimation unit 1452 may be configured to perform various correlation and peak detection algorithms.

[0159] Referring again to FIG. 14, offset estimation unit 1452 performs TO and FO offset estimation. That is, for example, offset estimation unit 1452 performs TO and FO offset estimation based on a reference waveform generated according to the techniques one or more of the techniques described above. Offset correction unit 1454 applies a correction based on the estimated TO and FO. That is, offset correction unit 1454 may compensate for estimated TO and FO. For example offset correction unit 1454 may perform timedomain shifting and frequency domain tuning. It should be noted that although two reference signals are illustrated in the example of FIG. 14, as described above, according to the techniques any number of reference signals may be combined to generate a reference waveform which may be used for TO and / or FO estimation and / or correction.

[0160] As described above, in Wi-Fi, a preamble may include a legacy preamble including a STF and a LTF and a HE preamble. Similarly, in some wireless communication system, various preambles lengths may be utilized. For example, a transmitter device may be configured to signal one of a short or a long preamble. According to the techniques herein, a comparison of TO and FO estimation performance using each of (i) a reference signal generated with a short preamble combined with one or more reference signals or (ii) a reference signal generated with a long preamble alone may be performed. The preamble length may be dynamically adjusted based on the comparison. For example, if a reference signal generated with a short preamble combined with one or more reference signals provides sufficient TO and FO estimation performance, a UE can determine the short preamble is sufficient for performing the TO and FO estimation. Conversely, a UE may determine that the short preamble is not sufficient for performing the TO and FO estimation. In the former case, the UE may continue to receive the transmitted signal without any further signaling to the transmission device. In the latter case, the UE may request that the transmission device transmit the long preamble because the short preamble is not sufficient for precise time and frequency synchronization even when it is combined with all other reference signals present in the waveform.

[0161] In this manner, receiver device 1450 represents an example of a device configured to select a first reference signal corresponding to a first type; select one or more additional reference signals; generate a reference waveform based on the first reference signal and the one or more additional reference signals; receive an orthogonal frequency division multiplexing (OFDM) waveform including the first reference signal and the one or more additional reference signals; and determine an offset by correlating the references signals in the reference waveform with the reference signals in the received OFDM transmission.FIG. 18: Performing Offset Estimation

[0162] FIG. 18 illustrates a block diagram of an example of a method 1800 forperforming offset estimation, according to some embodiments. The method shown in FIG. 18 may be used in conjunction with any of the systems, methods, or devices shown in the Figures, among other devices. In various embodiments, some of the method elements shown may be performed concurrently, in a different order than shown, or may be omitted. Additional method elements may also be performed as desired. As shown, this method may operate as follows.

[0163] At 1810, a user equipment device (UE), such as UE 106, may select reference signals. For example, a UE may select one or more 5G NR reference signals described above. Further, a UE may select a preamble and one or more pilot symbols, for example, as described above.

[0164] At 1820, the UE may generate a reference waveform based on the selected reference signals. For example, a UE may generate a reference waveform as described above.

[0165] At 1830, the UE may receive a OFDM waveform. For example, a UE may generate a OFDM waveform as described above.

[0166] At 1840, the UE may correlate selected reference signals in the reference wave for and the OFDM waveform. For example, a UE may perform correlation as described above. UE may determine an offset based on the correlation.

[0167] In some examples, UE may select a preamble length based on the offset.

[0168] In some examples, the offset is a time offset.

[0169] In some examples, the offset is a frequency offset.

[0170] In some examples, a selected reference signal is a preamble.

[0171] In some examples, a selected reference signal is a pilot symbol in a data field.

[0172] In some examples, a selected reference signal is a tracking reference signal (TRS).

[0173] In some examples, a selected reference signal is one of a Demodulation Reference Signal (DMRS), a Phase Tracking Reference Signal (PTRS), Primary Synchronization Signal (PSS), and an Secondary Synchronization Signal (SSS).

[0174] In some examples, the received OFDM waveform is a non-terrestrial transmission.

[0175] In some examples, the selected reference signals are within the same transmission cycle.

[0176] It is well understood that the use of personally identifiable information should follow privacy policies and practices that are generally recognized as meeting or exceeding industry or governmental requirements for maintaining the privacy of users. In particular, personally identifiable information data should be managed and handled so as to minimize risks of unintentional or unauthorized access or use, and the nature of authorized use should be clearly indicated to users.

[0177] Embodiments of the present disclosure may be realized in any of various forms. For example, some embodiments may be realized as a computer-implemented method, a computer- readable memory medium, or a computer system. Other embodiments may be realized using one or more custom-designed hardware devices such as ASICs. Still other embodiments may be realized using one or more programmable hardware elements such as FPGAs.

[0178] In some embodiments, a non-transitory computer-readable memory medium may be configured so that it stores program instructions and / or data, where the program instructions, if executed by a computer system, cause the computer system to perform a method, e.g., any of the method embodiments described herein, or, any combination of the method embodiments described herein, or, any subset of any of the method embodiments described herein, or, any combination of such subsets.

[0179] In some embodiments, a device (e.g., a UE 106) may be configured to include a processor (or a set of processors) including one or more baseband processors and one or more application processors and a memory medium, where the memory medium stores program instructions, where the processor is configured to read and execute the program instructions from the memory medium, where the program instructions are executable to implement any of the various method embodiments described herein (or, any combination of the method embodiments described herein, or, any subset of any of the method embodiments described herein, or, any combination of such subsets). The device may be realized in any of various forms.

[0180] Any of the methods described herein for operating a user equipment (UE) may be the basis of a corresponding method for operating a base station, by interpreting each message / signal X received by the UE in the downlink as message / signal X transmitted bythe base station, and each message / signal Y transmitted in the uplink by the UE as a message / signal Y received by the base station.

[0181] Although the embodiments above have been described in considerable detail, numerous variations and modifications will become apparent to those skilled in the art once the above disclosure is fully appreciated. It is intended that the following claims be interpreted to embrace all such variations and modifications.

Claims

CLAIMSWhat is claimed is:

1. A method to perform offset estimation, the method comprising: selecting a first reference signal corresponding to a first type; selecting a second reference signal corresponding to a second type; generating a reference waveform based on the first reference signal and the second reference signal; receiving an orthogonal frequency division multiplexing (OFDM) transmission including the first reference signal and the second reference signal; and determining an offset by correlating the first reference signal and the second reference signal in the reference waveform with the first reference signal and the second reference signal in the received OFDM transmission.

2. A method to perform offset estimation, the method comprising: selecting a first reference signal corresponding to a first type; selecting one or more additional reference signals; generating a reference waveform based on the first reference signal and the one or more additional reference signals; receiving an orthogonal frequency division multiplexing (OFDM) waveform including the first reference signal and the one or more additional reference signals; and determining an offset by correlating the references signals in the reference waveform with the reference signals in the received OFDM transmission.

3. The method of any of claims 1 or 2, further comprising selecting a preamble length based on the offset.

4. The method of any of claims 1-3, wherein the offset is a time offset.

5. The method of any of claims 1-4, wherein the offset is a frequency offset.

6. The method of any of claims 1-5, wherein the first reference signal is a preamble.

7. The method of claim 6, wherein a second or additional reference signal is a pilot symbol in a data field.

8. The method of any of claim 1-5, wherein the first reference signal is a tracking reference signal (TRS).

9. The method of claim 8, wherein a second or additional reference signal one of a Demodulation Reference Signal (DMRS), a Phase Tracking Reference Signal (PTRS), Primary Synchronization Signal (PSS), and an Secondary Synchronization Signal (SSS).

10. The method of any of claims 1-9, wherein the received OFDM transmission is a non-terrestrial transmission.

11. The method of any of claims 1-10, wherein the selected reference signals are within a same transmission cycle.

12. An apparatus of a user equipment (UE) configured to perform offset estimation, the apparatus comprising: one or more processors configured to: select a first reference signal corresponding to a first type; select a second reference signal corresponding to a second type; generate a reference waveform based on the first reference signal and the second reference signal; receive an orthogonal frequency division multiplexing (OFDM) transmission including the first reference signal and the second reference signal; and determine an offset by correlating the first reference signal and the second reference signal in the reference waveform with the first reference signal and the second reference signal in the received OFDM transmission.

13. An apparatus of a user equipment (UE) configured to perform offset estimation, the apparatus comprising: one or more processors configured to:select a first reference signal corresponding to a first type; select one or more additional reference signals; generate a reference waveform based on the first reference signal and the one or more additional reference signals; receive an orthogonal frequency division multiplexing (OFDM) waveform including the first reference signal and the one or more additional reference signals; and determine an offset by correlating the references signals in the reference waveform with the reference signals in the received OFDM transmission.

14. The apparatus of any of claims 12 or 13 wherein the one or more processors are further configured to select a preamble length based on the offset.

15. The apparatus of any of claims 12-14, wherein the offset is a time offset.

16. The apparatus of any of claims 12-15, wherein the offset is a frequency offset.

17. The apparatus of any of claims 12-16, wherein the first reference signal is a preamble.

18. The apparatus of any of claim 17, wherein a second or additional reference signal is a pilot symbol in a data field.

19. The apparatus of any of claims 12-16, wherein the first reference signal is a tracking reference signal (TRS).

20. The apparatus of any of claims 19, wherein a second or additional reference signal one of a Demodulation Reference Signal (DMRS), a Phase Tracking Reference Signal (PTRS), Primary Synchronization Signal (PSS), and an Secondary Synchronization Signal (SSS).

21. The apparatus of any of claims 12-20, wherein the received OFDM transmission is a non-terrestrial transmission.

21. The apparatus of any of claims 12-21, wherein the selected reference signals are within a same transmission cycle.

22. A baseband processor configured to cause a user equipment (UE) to perform any of the methods of claims 1-11.

23. A baseband processor configured to cause a base station to perform one or more of the methods of claims 1-11.

24. An apparatus configured to cause a user equipment (UE), having one or more processors coupled to a memory, to perform any of the methods of claims 1 to 11.

25. An apparatus configured to cause base station, having one or more processors coupled to a memory, to perform any of the methods of claims 1 to 11.

26. A computer program product, comprising computer instructions which, when executed by one or more processors, perform any of the operations described herein.

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