Systems and methods for supporting coherent transmission in non-terrestrial networks

Abstract

Disclosed herein are systems and methods for supporting coherent transmission in wireless networks such as non-terrestrial networks (NTNs). In one embodiment, a method performed by a wireless communication device includes starting an uplink transmission and performing one or more actions including creating a time gap within the uplink transmission and / or muting a portion of the uplink transmission to support timing advance of a continued uplink transmission. The method further includes performing time-frequency compensation during a time period created by performing the one or more actions and continuing the uplink transmission after performing the time-frequency compensation. In this way, a low-complexity method for enabling compensation for time-varying Doppler shifts is provided. This provides predictability that can be used in wireless networks such as, for example, NTSs to support coherent demodulation and optimized receiver implementations.

Description

[0001] Related Applications

[0002] This application claims the benefit of provisional patent application serial number 62 / 976,445, filed February 14, 2020, the disclosure of which is hereby incorporated by reference herein in its entirety. TECHNICAL FIELD

[0003] The present disclosure relates to coherent transmission in wireless networks, and in particular, to coherent transmission in non-terrestrial networks. BACKGROUND

[0004] In Third Generation Partnership Project (3GPP) Release 8, the Evolved Packet System (EPS) was specified. The EPS is based on the Long Term Evolution (LTE) radio network and the Evolved Packet Core (EPC). It was originally intended to provide voice and mobile broadband (MBB) services, but has continued to evolve to expand its functionality. Since Release 13, Narrowband Internet of Things (NB-IoT) and LTE for Machine Type Communication (MTC) (LTE-M) are part of the LTE specification and provide connectivity to massive Machine Type Communication (mMTC) services.

[0005] In 3GPP Release 15, the first version of the Fifth Generation (5G) System (5GS) was specified. This is a new generation of Radio Access Technologies (RATs) intended to serve use cases such as Enhanced Mobile Broadband (eMBB), Ultra-Reliable and Low Latency Communications (URLLC), and mMTC. The 5GS includes a New Radio (NR) access layer interface and a 5G Core Network (5GC). The NR physical layer and higher layers reuse parts of the LTE specification and add needed components when inspired by new use cases. One such component introduces a complex framework for beamforming and beam management to extend the support of 3GPP technologies to frequency ranges beyond 6 gigahertz (GHz).

[0006] In Release 15, 3GPP started work to prepare NR for operation in Non-Terrestrial Networks (NTN). The work was performed within the study item "NR to support Non-Terrestrial Networks" and resulted in 3GPP Technical Report (TR) 38.811 [1]. In Release 16, the work to prepare NR for operation in NTN networks continued in the study item "Solutions for NR to support Non-Terrestrial Network" [2]. In parallel, interest is growing to adapt NB-IoT and LTE-M for operation in NTN. Therefore, 3GPP Release 17 contains both a work item on NR NTN [3] and a study item on NB-IoT and LTE-M support for NTN [4].

[0007] The following sections provide a brief background description of some of the topics related to the systems and methods disclosed herein.

[0008] Satellite communications

[0009] A satellite Radio Access Network (RAN) is a type of NTN. A satellite RAN typically comprises the following components:

[0010] • a satellite referring to a space-borne platform;

[0011] • a ground gateway connecting the satellite to a base station or core network depending on the architecture choice;

[0012] • a feeder link referring to the link between the gateway and the satellite; and

[0013] • a service link referring to the link between the satellite and the user equipment (UE).

[0014] Depending on the orbital height, satellites can be classified as Low Earth Orbit (LEO), Medium Earth Orbit (MEO), or Geostationary Earth Orbit (GEO) satellites:

[0015] • LEO: typical height distribution in the range of 250-1,500 kilometers (km) with orbital period distribution in the range of 90-120 minutes,

[0016] • MEO: typical height distribution in the range of 5,000-25,000 km with orbital period distribution in the range of 3-15 hours, and

[0017] • GEO: height at approximately 35,786 km with an orbital period of 24 hours.

[0018] Communication satellites typically generate several beams over a given region. The coverage area of a beam is typically elliptical, which has traditionally been referred to as a cell. The coverage area of a beam is also often referred to as a spot beam. The coverage area of a beam can move over the Earth's surface as the satellite moves or can be Earth fixed to compensate for its motion with some beam pointing mechanism used by the satellite. The size of a spot beam depends on the system design, which can range from tens of kilometers to several thousand kilometers.

[0019] Figure 1 An example architecture of a satellite network with bent pipe transponders is shown. A bent pipe transponder essentially refers to repeating the feeder link signal on the service link. The elevation angle of the depicted service link is important as it determines the distance between the satellite and the device and the velocity of the satellite relative to the device.

[0020] In a LEO NTN, the satellite is moving at approximately 7.1 kilometers per second (km / s). This results in relativistic effects, including a Doppler shift of the carrier frequency on the service link of up to 24 parts per million (ppm) for a LEO satellite at 600 km altitude [2] (e.g., of the carrier frequency). The Doppler shift is also time-varying due to the satellite's motion over the sky. The Doppler shift can vary at up to 0.27 ppm per second (ppm / s) for a LEO satellite at 600 km altitude. The Doppler shift will affect (i.e., increase or decrease) the frequency received on the service link compared to the transmitted frequency. Also, the service link timing will be affected by the Doppler shift. In case the satellite moves towards the receiver, an increase of the observed frequency will be experienced and time will appear to run faster in the receiver compared to the transmitter.

[0021] Synchronisation

[0022] An LTE / NB-IoT / NR UE estimates the downlink (DL) frequency from a base station with a broadcast synchronization sequence (primary synchronization signal (PSS) / secondary synchronization signal (SSS)). The estimated frequency is used as a reference based on which it adjusts its time and frequency reference for both the determined DL (receive) and uplink (UL) (transmit) frequencies.

[0023] Due to the Doppler shift described above, the local frequency reference in the UE f Ref,UE will be tuned to a frequency f RX,UE during the initial DL synchronization, which has an offset f RX,UE relative to the ideal frequency (i.e., the satellite DL transmit frequency f IDEAL,DL ). fDoppler,DL :

[0024] .

[0025] The local frequency reference is used to determine both the UE's receive (RX) and transmit (TX) frequencies. In the simplest case of a time division duplex (TDD) network, the intended DL and UL frequencies (i.e. the frequencies of the received DL signal and the transmitted UL signal) are even identical: f IDEAL,DL and f IDEAL,UL

[0026] .

[0027] For simplicity, let's continue considering a TDD network. When the UE accesses the network on the physical random access channel (PRACH), its transmit frequency f TX_RA,UE will thus have an offset corresponding to the DL Doppler:

[0028] .

[0029] Due to the additional Doppler shift in the UL f Doppler,UL , the received signal on the network side will have a total frequency offset of compared to the ideal frequency:

[0030] .

[0031] If closed loop Doppler compensation is used, the network can estimate the Doppler shift based on the reception of e.g. the PRACH. It then communicates the offset to the UE, e.g. in the random access response (RAR) message. By , the UE adjusts its UL transmit frequency in the subsequent transmission to f TX,UE , thus cancelling the frequency offset of the received UL signal on the network (NW) side:

[0032] .

[0033] Since the UL and DL Doppler shifts are identical in a TDD system, the adjustment in the UL TX signal frequency relative to the received DL signal frequency can be expressed as or in relative numbers as .

[0034] In the above calculation, a static Doppler shift has been assumed. In reality, the Doppler shift f Doppler ​is time-varying and needs to be addressed once the UE enters radio resource control (RRC) connected mode f Doppler This time variation in [5], it is shown that the Doppler drift rate can be predicted and compensated by the UE during transmission in NTN.

[0035] While the compensation is described here for TDD NTN, similar approach can be taken for frequency division duplex (FDD) NTN.

[0036] Uplink timing

[0037] The description in the previous sections focused on the frequency offset caused by constant Doppler shift, but relativistic effects will also be seen in the time domain. The UE should also adjust the UL timing resolution (i.e. sampling rate) along with the UL transmission frequency accordingly. For the TDD system described in the previous sections, the UL timing resolution should be adjusted by a factor of relative to the DL timing resolution of the UE or should be adjusted by a factor of relative to the timing resolution used in the satellite.

[0038] To further illustrate the timing correction in the UE, Figure 2 illustrates how the UE can adjust its UL transmission timing resolution to compensate for the time drift of relative size Δ caused on the UE-to-satellite link. More specifically, Figure 2 illustrates a scenario where the UE transmits in the UL to a satellite that is moving away from the UE at an approximately constant speed v y relative to the UE. Since the Doppler shift f Doppler is negative, moving away from the UE that is transmitting causes the satellite receiver to experience a reduced carrier frequency relative to the UE transmission frequency. In order for the satellite to receive the signal at the correct timing corresponding to the sampling rate of the time resolution or t s , the UE needs to apply the mentioned compensation factor Δ to its transmission timing. Since in this example f Doppler is negative, this results in Δ < 1 and a reduced UE transmission timing resolution relative to the one used in the satellite. If the UL timing resolution is not adjusted by this amount, the UL signal received by the base station receiver will be time-drifted.

[0039] Currently, NR networks send timing advance (TA) commands to UEs in connected mode to maintain the UL timing. There are six (6) bits in the medium access control (MAC) control element (MAC-CE) to indicate the indexT A wherein . The UE uses to compute a new TA value N TA_new (in units of T c wherein T c = 0.509 ns ), wherein kHz is the subcarrier spacing (SCS) and This allows for a maximum change of the TA value of shown in the following table. To cope with a timing drift of say 40 μs / s kHz per second, several such commands per second are needed.

[0040] Table 1: Maximum change of the TA value in connected mode for various SCS.

[0041]

[0042] For NR, it has been noted that relying only on TA update commands to handle timing drift would result in excessive signaling overhead. For this reason, it has been proposed in [5] that the network should signal to the UE an estimated initial Doppler shift and Doppler variation rate to allow the UE to adjust its UL timing autonomously to account for timing drift due to Doppler (this timing drift can also be referred to as time dilation). In [2], it has also been proposed that the UE can adjust its UL timing based on timing drift information signaled from the network to the UE.

[0043] Coherent transmission

[0044] In Release 13, 3GPP specified NB-IoT and support for LTE-M, including bandwidth-reduced low-complexity (BL) UEs operating in coverage enhancement (CE) modes A and B. LTE BL / CE mode operation is referred to hereinafter as LTE-M operation. NB-IoT and LTE-M are designed to provide qualities such as deep indoor coverage, high system capacity, and long device battery life.

[0045] NB-IoT, LTE-M and other RATs use time repetition of radio blocks for improved coverage and reliability. NB-IoT for example does support up to 128 consecutive time repetitions of a narrowband physical uplink shared channel (NPUSCH) transmitted during up to four (4) seconds in the most extreme case. In 3GPP specifications this concept is referred to as "blind repetition" or just "repetition". Transmitting this type of repetition without waiting for feedback from the receiving node explains why in some cases the concept is referred to as blind repetition.

[0046] The receiving node can assume that the transmitting node provides a coherent waveform for any given antenna port. This allows the receiver to infer the channel through which the symbol on the antenna port is delivered from Channel through which another symbol on the same antenna port is conveyed [6]. This means that the transmitter presents to the receiver a well-defined time and frequency reference that meets strict requirements about keeping a constant reference frequency and a continuous phase trajectory.

[0047] Equation 1 illustrates that for a sampling rate of N samples on t s a defined, non-time-varying carrier frequency f c and phase the signal s meets the coherence requirement.

[0048] (Equation 1).

[0049] In addition to that, the 3GPP baseband specification provides a well-defined starting point t 0 and time length T for each repeated radio block as well as a prescribed starting phase

[0050] At the receiver, the repeated blocks are usually combined to improve the receiver processing gain. The well-defined transmitter requirements allow the receiver to adapt and optimize the reception combining method. The optimal combining scheme usually depends on the radio technology. In the case of NB-IoT and LTE-M, a popular combining method estimates the radio channel jointly for a group of consecutive radio blocks. This allows the receiver to improve the channel estimation and optimize the coherent demodulation performance across a group of repeated radio blocks.

[0051] If the above-mentioned transmitter coherence requirements are not assumed to be met, the receiving node has to resort to a less efficient combining method. For NB-IoT and LTE-M, the receiver will perform channel estimation on a per-received radio block basis. SUMMARY

[0052] Systems and methods are disclosed herein for supporting coherent transmission in a wireless network such as a non-terrestrial network (NTN). In one embodiment, a method performed by a wireless communication device includes starting an uplink transmission and performing one or more actions including creating a time gap within the uplink transmission and / or muting a portion of the uplink transmission to support timing advance (TA) of a continued uplink transmission. The method further includes performing time-frequency compensation during a time period created by performing the one or more actions and continuing the uplink transmission after performing the time-frequency compensation. In this way, a low complexity method for implementing compensation for time-varying Doppler shifts is provided. This provides predictability that can be used in a wireless network such as, for example, an NTN to support coherent demodulation and optimized receiver implementation.

[0053] In one embodiment, performing the time-frequency compensation includes performing the time-frequency compensation such that, during the time period created by performing the action, time compensation, frequency compensation, or both time compensation and frequency compensation are applied at the wireless communication device.

[0054] In one embodiment, the uplink transmission includes a plurality of consecutive repetitions of a base transmission. In another embodiment, the uplink transmission consists of a plurality of consecutive repetitions of a base transmission. In one embodiment, the uplink transmission is a Narrow Band-Internet of Things (NB-IoT) or Long-Term Evolution (LTE) for Machine Type Communications (MTC) (LTE-M) uplink transmission that includes a plurality of consecutive repetitions of a base transmission. In another embodiment, the uplink transmission is a NB-IoT or LTE-M uplink transmission that consists of a plurality of consecutive repetitions of a base transmission. In one embodiment, the base transmission is a Narrow Band Physical Uplink Shared Channel (NPUSCH). In another embodiment, the base transmission is a Physical Uplink Shared Channel (PUSCH).

[0055] In one embodiment, performing the one or more actions includes creating a time gap within the uplink transmission. In one embodiment, creating the time gap within the uplink transmission includes creating the time gap within a transmission time interval (TTI) of the uplink transmission. In one embodiment, the TTI has a length that is greater than 1 subframe, greater than 1 radio frame, greater than 1 millisecond (ms), greater than 10 ms, or greater than 1 second.

[0056] In one embodiment, performing the time-frequency compensation includes: (a) performing the one or more actions to compensate for an estimated Doppler shift related to the uplink transmission, (b) performing the one or more actions to compensate for an estimated time dilation related to the uplink transmission, or (c) both (a) and (b).

[0057] In one embodiment, performing the time-frequency compensation comprises: (a) performing one or more actions to compensate for an estimated Doppler shift caused by motion of a satellite of a satellite-based radio access network (RAN) that is to receive the uplink transmission, (b) performing one or more actions to compensate for an estimated time dilation caused by motion of the satellite of the satellite-based RAN that is to receive the uplink transmission, or (c) both (a) and (b).

[0058] In one embodiment, performing the time-frequency compensation comprises adjusting a transmission frequency of the continued uplink transmission. In one embodiment, the adjustment of the transmission frequency is performed to compensate for an estimated Doppler shift or a change in the estimated Doppler shift related to the uplink transmission.

[0059] In one embodiment, performing the time-frequency compensation comprises adjusting a time resolution, a sampling rate, or both the time resolution and the sampling rate of the continued uplink transmission. In one embodiment, the adjustment of the time resolution, the sampling rate, or both the time resolution and the sampling rate is performed to compensate for an estimated time dilation or a change in the estimated time dilation related to the uplink transmission. In one embodiment, the adjustment of the time resolution, the sampling rate, or both the time resolution and the sampling rate lengthens or compresses the continued transmission in the time domain.

[0060] In one embodiment, performing the time-frequency compensation comprises adjusting an uplink transmission timing of the wireless communication device. In one embodiment, the adjustment of the uplink transmission timing is performed to compensate for an estimated time dilation or a change in the estimated time dilation related to the uplink transmission.

[0061] In one embodiment, performing the time-frequency compensation comprises shifting a starting point of a remaining portion of the uplink transmission that is transmitted by the continued uplink transmission. In one embodiment, the shifting of the starting point is performed to compensate for an estimated time dilation or a change in the estimated time dilation related to the uplink transmission.

[0062] In one embodiment, the method further comprises receiving a configuration of one or more parameters from the network node, the one or more parameters defining the location(s) of the time gap(s) to be created in the uplink transmission or one or more values to be used by the wireless communication device to derive the location(s) of the time gap(s) to be created in the uplink transmission.

[0063] In one embodiment, the method further comprises receiving a configuration of one or more parameters from the network node, the one or more parameters defining when to perform the time-frequency compensation or one or more values to be used by the wireless communication device to derive when to perform the time-frequency compensation.

[0064] In one embodiment, creating the time gap comprises delaying a portion of the uplink transmission, muting a portion of the uplink transmission, puncturing a portion of the uplink transmission, dropping one or more symbols of the uplink transmission, not using one or more symbols of the uplink transmission, and / or blanking out one or more symbols of the uplink transmission.

[0065] In one embodiment, the location of the one or more time gaps is based on a satellite ephemeris and / or a cyclic prefix (CP) duration.

[0066] Corresponding embodiments of a wireless communication device are also disclosed. In one embodiment, the wireless communication device is adapted to start an uplink transmission and perform one or more actions comprising creating a time gap within the uplink transmission and / or muting a portion of the uplink transmission to support a TA for continued uplink transmission. The wireless communication device is further adapted to perform time-frequency compensation during a time period created by performing the one or more actions and continue the uplink transmission after performing the time-frequency compensation.

[0067] In another embodiment, the wireless communication device comprises one or more transmitters, one or more receivers, and processing circuitry associated with the one or more transmitters and the one or more receivers. The processing circuitry is configured to cause the wireless communication device to start an uplink transmission and perform one or more actions comprising creating a time gap within the uplink transmission and / or muting a portion of the uplink transmission to support a TA for continued uplink transmission. The processing circuitry is further configured to cause the wireless communication device to perform time-frequency compensation during a time period created by performing the one or more actions and continue the uplink transmission after performing the time-frequency compensation.

[0068] Embodiments of a computer program are also disclosed. In one embodiment, a computer program is provided which, when executed on at least one processor, causes the at least one processor to carry out the method of operation of a wireless communication device according to any of the embodiments disclosed herein. In one embodiment, a carrier containing the computer program is provided, wherein the carrier is one of an electronic signal, an optical signal, a radio signal, or a computer readable storage medium.

[0069] In another embodiment, a non-transitory computer-readable medium is provided. The non-transitory computer-readable medium stores instructions executable by processing circuitry of a wireless communication device, whereby the wireless communication device is operable to initiate an uplink transmission and perform one or more actions comprising creating a time gap within the uplink transmission and / or muting a portion of the uplink transmission to support a TA of a continued uplink transmission. By execution of the instructions by the processing circuitry, the wireless communication device is further operable to perform time-frequency compensation during a time period created by the performance of the one or more actions and continue the uplink transmission after the performance of the time-frequency compensation.

[0070] Embodiments of methods performed by a network node are also disclosed. In one embodiment, a method performed by a network node comprises configuring a wireless communication device with one or more parameters. In one embodiment, the one or more parameters either (a) define a location of one or more time gaps to be used by the wireless communication device to perform time-frequency compensation during an uplink transmission or a location of one or more portions of the uplink transmission to be muted to perform time-frequency compensation, or (b) define one or more values to be used by the wireless communication device to derive a location of one or more time gaps to be used by the wireless communication device to perform time-frequency compensation during an uplink transmission or a location of one or more portions of the uplink transmission to be muted to perform time-frequency compensation. In another embodiment, the one or more parameters either (a) define when time-frequency compensation is performed during an uplink transmission, or (b) define one or more values to be used by the wireless communication device to derive when time-frequency compensation is performed during an uplink transmission.

[0071] In one embodiment, the uplink transmission comprises a plurality of consecutive repetitions of a base transmission. In another embodiment, the uplink transmission consists of a plurality of consecutive repetitions of a base transmission. In one embodiment, the uplink transmission is a NB-IoT or LTE-M uplink transmission comprising a plurality of consecutive repetitions of a base transmission. In another embodiment, the uplink transmission is a NB-IoT or LTE-M uplink transmission consisting of a plurality of consecutive repetitions of a base transmission. In one embodiment, the base transmission is a NPUSCH. In another embodiment, the base transmission is a PUSCH.

[0072] In one embodiment, the one or more time gaps are created within a TTI of the uplink transmission. In one embodiment, the TTI has a length that is greater than 1 subframe, greater than 1 radio frame, greater than 1 ms, greater than 10 ms, or greater than 1 second.

[0073] In one embodiment, the position of the one or more time gaps is based on satellite ephemeris and / or CP duration, or the one or more positions of the time when time-frequency compensation is to be performed by the wireless communication device is based on satellite ephemeris and / or CP duration.

[0074] Corresponding embodiments of a network node are also disclosed. In one embodiment, the network node is adapted to configure a wireless communication device with one or more parameters. In one embodiment, the one or more parameters either (a) define the position of one or more time gaps to be used by the wireless communication device to perform time-frequency compensation during an uplink transmission or the position of one or more portions of the uplink transmission to be muted to perform time-frequency compensation, or (b) define one or more values to be used by the wireless communication device to derive the position of one or more time gaps to be used by the wireless communication device to perform time-frequency compensation during an uplink transmission or the position of one or more portions of the uplink transmission to be muted to perform time-frequency compensation. In another embodiment, the one or more parameters either (a) define when time-frequency compensation is performed during an uplink transmission, or (b) define one or more values to be used by the wireless communication device to derive when time-frequency compensation is performed during an uplink transmission.

[0075] In one embodiment, the network node is adapted to configure a wireless communication device with one or more parameters. In one embodiment, the one or more parameters either (a) define when time-frequency compensation is performed during an uplink transmission, or (b) define one or more values to be used by the wireless communication device to derive when time-frequency compensation is performed during an uplink transmission.

[0076] In one embodiment, the network node comprises processing circuitry configured to cause the network node to configure a wireless communication device with one or more parameters. In one embodiment, the one or more parameters either (a) define the position of one or more time gaps to be used by the wireless communication device to perform time-frequency compensation during an uplink transmission or the position of one or more portions of the uplink transmission to be muted to perform time-frequency compensation, or (b) define one or more values to be used by the wireless communication device to derive the position of one or more time gaps to be used by the wireless communication device to perform time-frequency compensation during an uplink transmission or the position of one or more portions of the uplink transmission to be muted to perform time-frequency compensation. In another embodiment, the one or more parameters either (a) define when time-frequency compensation is performed during an uplink transmission, or (b) define one or more values to be used by the wireless communication device to derive when time-frequency compensation is performed during an uplink transmission.

[0077] In one embodiment, a network node includes processing circuitry configured to cause the network node to configure a wireless communication device with one or more parameters. In one embodiment, the one or more parameters either (a) define when time-frequency compensation is performed during an uplink transmission, or (b) define one or more values to be used by the wireless communication device to derive when time-frequency compensation is performed during an uplink transmission.

[0078] Embodiments of a computer program are also disclosed. In one embodiment, a computer program includes instructions which, when executed on at least one processor, cause the at least one processor to carry out the method of operation of a network node in accordance with any of the embodiments described herein. In one embodiment, a carrier containing the computer program is provided. The carrier is one of an electronic signal, an optical signal, a radio signal, or a computer readable storage medium.

[0079] In one embodiment, a non-transitory computer readable medium is provided. The non-transitory computer readable medium includes instructions executable by processing circuitry of a network node, whereby the network node is operable to configure a wireless communication device with one or more parameters. In one embodiment, the one or more parameters either (a) define locations of one or more time gaps to be used by the wireless communication device to perform time-frequency compensation during an uplink transmission or locations of one or more portions of an uplink transmission to be muted to perform time-frequency compensation, or (b) define one or more values to be used by the wireless communication device to derive locations of one or more time gaps to be used by the wireless communication device to perform time-frequency compensation during an uplink transmission or locations of one or more portions of an uplink transmission to be muted to perform time-frequency compensation. In another embodiment, the one or more parameters either (a) define when time-frequency compensation is performed during an uplink transmission, or (b) define one or more values to be used by the wireless communication device to derive when time-frequency compensation is performed during an uplink transmission.

[0080] In one embodiment, a non-transitory computer readable medium is provided. The non-transitory computer readable medium includes instructions executable by processing circuitry of a network node, whereby the network node is operable to configure a wireless communication device with one or more parameters. In one embodiment, the one or more parameters either (a) define when time-frequency compensation is performed during an uplink transmission, or (b) define one or more values to be used by the wireless communication device to derive when time-frequency compensation is performed during an uplink transmission. BRIEF DESCRIPTION OF DRAWINGS

[0081] The accompanying drawings, which are incorporated in and form a part of the specification, illustrate several aspects of the present disclosure and together with the description, serve to explain the principles of the present disclosure.

[0082] Figure 1 An example architecture of a satellite network with bent pipe transponders is shown;

[0083] Figure 2 It is explained how a user equipment (UE) can adjust its uplink (UL) transmission timing resolution to compensate for a time drift of relative size Δ induced on the UE-to-satellite link;

[0084] Figure 3 One example of a wireless communication system in which embodiments of the present disclosure can be implemented is explained;

[0085] Figure 4 It is explained how a UE according to embodiments of the present disclosure can adjust its UL transmission timing resolution (i.e. the sampling rate of the discrete time intervals t s ) to compensate for increased Doppler shift;

[0086] Figure 5 It is explained how a UE can adjust its UL transmission timing by adjusting the start time of the repeated signal by dTA to compensate for a satellite moving away from the UE during a transmission time interval (TTI);

[0087] Figure 6 It is explained how a UE according to embodiments of the present disclosure can adjust its UL transmission timing by adjusting the start time of the signal by dTA and by adjusting the time resolution of the repeated signal by Δ1 / Δ2;

[0088] Figure 7 It is explained how a UE according to embodiments of the present disclosure can insert a time gap into the UL transmission by the UE to allow performing time-frequency compensation;

[0089] Figure 8 It is explained how a UE according to embodiments of the present disclosure can mute a part of the UL transmission to support timing advance (TA) of a subsequent part of the UL transmission;

[0090] Figure 9 It is explained how a network node and a UE of a wireless communication system according to embodiments of the present disclosure can operate; Figure 3

[0091] Figure 10 further illustrates some aspects of embodiments of the present disclosure related to creating a time gap or muting the UL transmission to enable time-frequency compensation during the UL transmission;

[0092] Figures 11 to 13 is a schematic block diagram of an example embodiment of a network node;

[0093] Figure 14 and​Figure 15 is a schematic block diagram of an example embodiment of a UE;

[0094] Figure 16 An example embodiment of a communication system in which embodiments of the disclosure can be implemented is described;

[0095] Figure 17 An example embodiment of a host, base station and UE is described; Figure 16

[0096] Figures 18 to 21 is a flowchart of an example embodiment of a method implemented in a communication system such as the communication system of Figure 16 DETAILED DESCRIPTION

[0097] The embodiments set forth below represent the information given to enable those skilled in the art to practice the embodiments and illustrate the best mode of practicing them. Upon reading the following description of the embodiments, one skilled in the art will understand how to implement the concept using alternative embodiments or applications. Such modifications to the embodiments are intended to fall within the scope of the disclosure. The disclosure is not limited to the embodiments described herein but is limited only by the claims.

[0098] Some embodiments of the application will now be described in greater detail with reference to the drawings. Other embodiments of the application are within the scope of the disclosure, which is not limited to the embodiments described herein; rather, the embodiments are provided to give a more detailed description of the application so that others skilled in the art can better understand the application.

[0099] In general, unless otherwise indicated, all terms used herein are to be interpreted according to their ordinary meaning in the technical field of the disclosure. All references to a / an / the element, apparatus, component, means, step, etc. are to be interpreted openly as referring to at least one instance of whatever is referred to unless indicated otherwise. The steps of any methods disclosed herein do not have to be performed in the exact order disclosed unless explicitly stated as such. Any of the embodiments of the disclosure can be implemented in any of the ways described herein. Similarly, any of the advantages of the embodiments of the disclosure can be applied to any of the embodiments of the disclosure and vice versa. Other objects, features and advantages of the present embodiments will become apparent from the description herein.

[0100] Radio node: As used herein, a "radio node" is either a radio access node or a wireless communication device. ​​

[0101] Radio access node: As used herein, a “radio access node” or “radio network node” or “radio access network node” is any node of a radio access network (RAN) of a cellular communications network that operates to wirelessly transmit and / or receive signals. Some examples of radio access nodes include, but are not limited to, a base station (e.g., a NR base station (gNB) of a Third Generation Partnership Project (3GPP) Fifth Generation (5G) New Radio (NR) network or an enhanced or evolved Node B (eNB) of a 3GPP Long Term Evolution (LTE) network), a high- power or macro base station, a low-power base station (e.g., a micro base station, a pico base station, a home eNB, etc.), a relay node, a network node that implements part of the functionality of a base station (e.g., a network node that implements a gNB-Central Unit (gNB-CU) or a network node that implements a gNB-Distributed Unit (gNB-DU)), or a network node that implements part of the functionality of another type of radio access node. In the context of an NTN, a radio access node such as a base station can be fully or partially integrated in a satellite or a gateway.

[0102] Core network node: As used herein, a “core network node” is any type of node in a core network or is any node that implements core network functionality. Some examples of core network nodes include, for example, a mobility management entity (MME), a packet data network gateway (P-GW), a service capability exposure function (SCEF), a home subscriber server (HSS), etc. Some other examples of core network nodes include nodes that implement an access and mobility function (AMF), a user plane function (UPF), a session management function (SMF), an authentication server function (AUSF), a network slice selection function (NSSF), a network exposure function (NEF), a network function (NF) repository function (NRF), a policy control function (PCF), a unified data management (UDM), etc.

[0103] Communication device: As used herein, a “communication device” is any type of device that can access a network. Some examples of communication devices include, but are not limited to: mobile phones, smartphones, sensor devices, meters, vehicles, household appliances, medical appliances, media players, cameras, or any type of consumer electronic, for instance, but not limited to, television, radio, lighting arrangements, tablet computers, laptop computers, or personal computers (PC). A communication device can be a portable, hand-held, computer- included, or vehicle-mounted computing device enabling wireless or wired connectivity to the Internet.

[0104] Wireless communication device: One type of communication device is a wireless communication device, which can be any type of wireless device that can access a wireless network (e.g., a cellular network), i.e., be served by it. Some examples of wireless communication devices include, but are not limited to: user equipment devices (UEs) in 3GPP- networks, machine-type communication (MTC) devices, and Internet of Things (IoT) devices. Such a wireless communication device can be, or can be integrated into, a mobile phone, a smart phone, a sensor device, a meter, a vehicular, a household appliance, a medical appliance, a media player, a camera, or any type of consumer electronic, such as, but not limited to, a television, a radio, a lighting arrangement, a tablet computer, a laptop, or a PC. The wireless communication device can be a portable, hand-held, computer- included, or vehicle-mounted mobile device, enabled to communicate voice and / or data via a wireless connection.

[0105] Network node: As used herein, “network node” is any node that is part of a cellular communications network / system, either a core network or a RAN.

[0106] It is noted that the description given herein focuses on 3GPP cellular communications systems, and as such 3GPP terminology or terminology similar to 3GPP terminology is often used. However, the concepts disclosed herein are not limited to 3GPP systems.

[0107] It is noted that in the description herein the term “cell” can be referred to; however, especially with respect to 5G NR concepts, beams can be used instead of cells, and as such it is important to note that the concepts described herein are equally applicable to both cells and beams.

[0108] Due to the Doppler shift observed for low earth orbit (LEO) satellites, there is currently some (or certain) challenges in non-terrestrial networks (NTNs) when coherent waveforms are to be provided on the service link. In [5], it is proposed to allow a UE to autonomously adjust its transmission timing and transmission frequency to continuously compensate for the time-varying Doppler shift experienced in LEO NTNs. To support long transmission time intervals (TTIs) in narrowband internet of things (NB-IoT) and LTE for MTC (LTE-M), such self-adjustment is an important proposal to present coherent waveforms to the NTN base station receiver. However, the ability of a UE to continuously adjust its time and frequency reference can depend on the UE implementation and the size of the Doppler shift and can be difficult to implement in low-complexity UE implementations.

[0109] Certain aspects of the present disclosure and their embodiments can provide solutions to the above-described or other challenges. The present disclosure provides systems and methods for modifying uplink (UL) transmission format in NTN to ensure that the transmission is coherent. This is particularly relevant for NB-IoT and LTE-M, where coherent transmission over long TTI is used to improve coverage. In the present disclosure, systems and methods for determining how a UE should correct its UL time and / or frequency reference during extended UL transmission to compensate for the time-varying Doppler shift present in LEO and medium earth orbit (MEO) NTN are disclosed.

[0110] Embodiments are disclosed herein for providing a low-complexity method for performing UL time-frequency correction for Doppler compensation in NTN in a way that allows the base station to optimize its receiver implementation.

[0111] Certain embodiments can provide one or more of the following technical advantages. Embodiments of the systems and methods disclosed herein support a well-defined low-complexity method for implementing compensation for time-varying Doppler shift. This provides predictability that can be used in NTN to support coherent demodulation and optimized receiver implementation. Coherent demodulation refers to a receiver knowing (or having estimated) the channel (i.e., its strength (or gain) and phase) and can compensate for it.

[0112] Figure 3 One example of a wireless communication system 300 in which embodiments of the present disclosure can be implemented is illustrated. As illustrated, the wireless communication system 300 includes a satellite-based RAN that includes satellites 302 (i.e., space or airborne radio access nodes or platforms) and one or more gateways 304 that interconnect the satellites 302 to ground-based base station components 306. The functionality of the base stations described herein can be implemented in the satellites 302 or can be distributed between the satellites 302 and the ground-based base station components 306 (e.g., the satellites 302 can implement L1 functionality and the ground-based base station components 306 can implement L2 and L3 functionality). In this example, a UE 308 is in communication with the satellite RAN via the satellites 302. The UE 308 is one example of a wireless communication device. Note that the wireless communication system 300 is just one example of a wireless communication system that uses NTN for radio access. Embodiments disclosed herein are equally applicable to any such system.

[0113] A description is now provided of some example embodiments of the present disclosure. In the following set of embodiments, it is assumed that a UE (e.g., the UE 308) is supported by one or more time-frequency references. One reference frequency f s The time resolution (i.e., sampling rate) of the signal in the transmitter is determined to bet s =1 / f s A reference frequency f c Sure UL transmission frequency This refers to the carrier frequency on which the transmitted signal is modulated. The two time-frequency references mentioned can be generated from the same time-frequency source or from separate time-frequency sources. The time-frequency source can be defined, for example, by a local oscillator.

[0114] Regarding compensation for time-frequency reference, in one embodiment, the UE continuously adjusts its UL transmission frequency during the TTI to compensate for, for example, estimated time-varying Doppler shift caused by satellite velocity.

[0115] In one embodiment, the UE modifies its UL transmission frequency at specified time intervals during the TTI to compensate for, for example, estimated time-varying Doppler shift caused by satellite velocity.

[0116] In one embodiment, the adjustment of the UL transmission timing used to compensate for the time dilation caused by satellite velocity is implemented as a signal sampling rate. t s Adjustments. For those made by k The signal TTI is defined by a symbol. N For each of the samples, this adjustment will either lengthen or shorten the length of each symbol. t s ·N It will also gradually delay or advance the start of each symbol. The signal sampling rate can be adjusted continuously within the TTI or at specified time intervals.

[0117] Figure 4 This illustrates an example where the UL transmission timing resolution (i.e., sampling rate) of the UE's transmitted signal is adjusted every three samples using factors ∆1, ∆2, and ∆3 to compensate for increased timing drift and increased negative Doppler shift on the radio link caused by the communication satellite leaving the UE at an increased speed. In other words, Figure 4 This explains how the UE can adjust its UL transmission timing resolution (i.e., sampling rate) at discrete time intervals. t s This is to compensate for the increased Doppler frequency shift. Here, the sampling rate is adjusted every three samples.

[0118] The sampling rate can be adjusted in the frequency domain using the following Fourier (F) transform time / frequency relationship:

[0119]

[0120] in s It represents the signal in the time domain.S is the signal represented in the frequency domain, t s is the original sampling rate to be adjusted, is the frequency resolution (e.g. subcarrier spacing) and is the adjustment factor.

[0121] In one embodiment, the adjustment of the transmission timing is implemented as a shift of the transmission starting point, i.e. as a timing advance (TA). The transmission timing can be adjusted continuously within a TTI or at specified time intervals. Figure 5 It is illustrated how the UE can adjust its UL transmission timing to compensate for a satellite moving away from the UE during a TTI by adjusting the start time of the repeated signal by dTA. In other words, Figure 5 An example is shown in which the transmission within a TTI is defined by a basic signal repeated once. The transmission timing is advanced by dTA at the start of the repeated transmission in this example to compensate for a satellite moving away from the UE. The unmodified version of the repeated transmission is shown as a reference using dashed lines.

[0122] In yet another example, Figure 6 A transmission defined by a basic signal repeated once is shown. At the start of the repetition, the transmission timing is adjusted by dTA to compensate for a satellite moving away from the UE and the timing resolution is adjusted by Δ2 / Δ1 to compensate for the increased negative Doppler shift. The unmodified version of the repeated transmission is shown as a reference using dashed lines. In other words, Figure 6 It is illustrated how the UE can adjust its UL transmission timing by adjusting the start time of the signal by dTA and the time resolution of the repeated signal by Δ1 / Δ2.

[0123] With regard to the timing of the step-wise time-frequency compensation, in one embodiment, the mentioned time-frequency correction is performed at fixed time intervals within a TTI. These fixed time intervals within a TTI can be defined, e.g., in a technical specification.

[0124] In one embodiment, the time-frequency correction is performed at time intervals within a TTI determined by a network node and is signaled to the transmitting UE. The signaling can be defined in the physical layer, e.g., in a random access response (RAR) or downlink control information (DCI) message. It can also be defined in the medium access control (MAC) layer or the radio resource control (RRC) layer. The signaling can be broadcast signaling or UE-specific signaling.

[0125] The time intervals can define, e.g., a periodicity such that the maximum timing error during any period with TTI defined by the timing drift aggregated during the period does not exceed a maximum threshold, e.g., ¼ of the cyclic prefix (CP) duration, regardless of the satellite position.

[0126] Alternatively, the time and frequency compensation is performed at a time instance within a TTI determined by when the aggregated timing drift equals or exceeds a threshold. Also, this threshold can be determined based on the CP duration or a fraction thereof. In one example, the time and frequency compensation is performed once the aggregated timing drift equals ¼ of the CP.

[0127] Instead of determining the mentioned time interval based on a tolerable timing error, a tolerable frequency error can be used as an indication for determining the time interval.

[0128] To support these alternatives, the network and the UE need to mutually understand the time and frequency drift. The network can determine the time drift based on a measurement of the Doppler shift of a physical random access channel (PRACH) transmission of the UE (at the time of the UE accessing the network) or a calculation of the Doppler shift based on the satellite ephemeris and the UE position. The network can determine the frequency drift, i.e. the rate of change of the Doppler shift (when the UE is in RRC connected state), by a calculation based on the satellite ephemeris (see [5]) or continuous measurements of the Doppler shift of physical uplink control channel (PUCCH) / physical uplink shared channel (PUSCH) transmissions. The network can in addition signal its estimate of the time and frequency drift to the UE to support the mentioned mutual understanding, e.g. as mentioned in Technical Report (TR) 38.821 [2]. Alternatively, the UE can determine the time and frequency drift in a similar way and signal its estimate to the network.

[0129] The length of the transmission segment between the mentioned time intervals can be determined based on the satellite position or angle, the carrier frequency or transmission frequency, or the satellite elevation angle.

[0130] The time intervals can be determined in terms of samples, symbols, slots, subframes, frames or by the number of repetitions of the signal.

[0131] Regarding additional support for time-frequency compensation, in one embodiment, the UE can insert or create a time gap in the TTI of the UL transmission for performing the mentioned time-frequency correction. The gap can be defined, e.g., by a delay of a second part of the signal as explained in Figure 7 or alternatively by a set of unused, dropped, muted or punctured symbols in the transmission.

[0132] Figure 7 A time gap inserted by a delay of a part of the signal is illustrated.

[0133] Figure 7The delay shown in FIG. 1 can also correspond to a correction of the UL transmission timing, where the transmission timing of the second part of the signal is delayed relative to the first part to compensate for cases where the satellite is moving closer to the UE that is transmitting.

[0134] The time-frequency compensation can be performed during an inserted / created time gap. Some UEs can need such a time gap to be able to switch / adjust settings before continuing transmission. Other UEs can be able to switch / adjust very quickly, but a time gap can still be used as a guard period. As described below with reference to Figure 8 In some cases, it can be necessary to mute a part of the UL transmission to support the TA of a subsequent part of the UL transmission, as described below with reference to

[0135] Figure 8 It is shown how the last part of the first signal can be muted to support the TA of the repeated signal, as first described in Figure 5 and Figure 6 the repeated signal in FIG. 1. Figure 8 It is described how the UE can compensate for its UL transmission timing by muting the last part of the first signal and then adjusting the start time of the repeated signal by dTA and adjusting the time resolution of the repeated signal by Δ2 / Δ1.

[0136] In one embodiment, a transmission gap is specified during which the UE can receive downlink (DL) transmissions, allowing the UE to improve its time-frequency correction.

[0137] The time gap can be determined in terms of samples, symbols, slots, subframes, or frames.

[0138] Figure 9 It is described how a UE can perform time-frequency compensation according to at least some of the embodiments described above. Figure 3of the UE 308 and the BS 306 of the satellite-based RAN wireless communication system 300. Note that optional steps are represented by dashed lines or boxes. As explained, the BS 306 optionally provides the UE 308 with a configuration that configures the UE 308 with one or more parameters that enable the UE 308 to perform time-frequency compensation according to any of the embodiments described herein (step 900). For example, in one embodiment, the configuration for time-frequency compensation either defines a location of a time gap in the UL transmission or defines a parameter(s) that are used by the UE 308 to derive the location of the time gap in the UL transmission. For example, as described above, the one or more parameters can indicate a time interval or periodicity or a time gap. As another example, the one or more parameters can include a frequency drift, i.e., a rate of change of the Doppler shift (when the UE 308 is in an RRC connected state). In another embodiment, the configuration for time-frequency compensation either defines when the UE 308 is to perform time-frequency compensation during the UL transmission or defines one or more values to be used by the UE 308 to derive when to perform time-frequency compensation during the UL transmission.

[0139] The UE 308 starts the (e.g., scheduled) UL transmission (step 902). For example, the UL transmission can be a UL transmission that consists of multiple consecutive repetitions of a base transmission on a long TTI (e.g., up to a four second TTI). Note that the term “base transmission” is used herein to refer to the transmission that is being repeated in each of the repetitions of the UL transmission. Also, when referring to the UL transmission consisting of multiple consecutive repetitions, the TTI of the UL transmission is the total time period in which the repetitions are transmitted. This is to be distinguished from the TTI of a single repetition. For example, the UL transmission can be a NB-IoT transmission that includes multiple repetitions, a LTE or LTE-M transmission that includes multiple repetitions, etc. Moreover, the base transmission can be, for example, a PUSCH or a narrowband PUSCH (NPUSCH).

[0140] During the UL transmission, the UE 308 performs one or more actions that include either creating a time gap in the UL transmission during which the UE 308 is to perform time-frequency correction (see, e.g., FIG. 4A) and / or muting a portion of the UL transmission to support a TA for continued UL transmission (see, e.g., FIG. 4B) (step 904). The UE 308 performs the time-frequency correction (step 906). The UE 308 performs the time-frequency correction or compensation during the time period defined by the action(s) of step 904. Figure 7 Figure 8 For example, if a time gap is created, the UE 308 performs the time-frequency correction during the created time gap (see, e.g., FIG. 4A) (step 908). As another example, if a portion of the UL transmission is muted to support a TA for continued UL transmission, the UE 308 performs the time-frequency correction during the muted portion of the UL transmission (see, e.g., FIG. 4B) (step 910).

[0141] For example, if a time gap is created, the UE 308 performs the time-frequency correction during the created time gap (see, e.g., FIG. 4A) (step 908). As another example, if a portion of the UL transmission is muted to support a TA for continued UL transmission, the UE 308 performs the time-frequency correction during the muted portion of the UL transmission (see, e.g., FIG. 4B) (step 910). Figure 7 ​performs one or more actions (e.g., delaying the start of the remaining portion of the UL transmission). Note that a time gap is created during the TTI of the UL transmission. Also note that a TTI can have a length that is greater than 1 subframe, greater than 1 radio frame, greater than 1 millisecond (ms), greater than 10 ms, or greater than 1 second, and can be defined in any desired unit (e.g., number of symbols, number of slots, number of subframes, number of radio frames, etc.).

[0142] As another example, if a portion of the UL transmission is muted, the UE 308 performs one or more actions (e.g., advancing the start of the remaining portion of the UL transmission) during the time period in which the UL transmission is muted (see, e.g., FIG. 9). Figure 8

[0143] The UE 308 can perform time-frequency correction in accordance with any of the embodiments described above. In some embodiments, performing time-frequency compensation includes performing one or more actions to compensate for an estimated Doppler shift and / or a change in the estimated Doppler shift caused, e.g., by motion of a satellite of a satellite-based RAN that is to receive the UL transmission (e.g., motion relative to the UE 308) and / or performing one or more actions to compensate for an estimated time dilation and / or a change in the estimated time dilation caused, e.g., by motion of a satellite of a satellite-based RAN that is to receive the UL transmission (e.g., motion relative to the UE 308). For example, the UE 308 can adjust its UL transmit frequency to compensate for an estimated Doppler shift and / or a change in the Doppler shift caused, e.g., by satellite velocity (e.g., relative to the UE 308). As another example, the UE 308 can additionally or alternatively adjust its UL transmit timing to compensate for time dilation and / or a change in the time dilation caused, e.g., by satellite velocity (e.g., relative to the UE 308), as described above by, e.g., adjusting a signal sampling rate t s As another example, UL transmit timing can be adjusted by shifting a starting point of transmission of the remaining portion of the UL transmission (e.g., a starting point for resuming the UL transmission in step 908).

[0144] Note that the calculations used by the UE 308 for compensation can be performed, e.g., in parallel with the UL transmission. So, those calculations can be performed, e.g., before the time gap is created or the UL transmission is muted. Thus, the calculations used by the UE 308 to perform time-frequency compensation can be calculated before the time gap / muting or performed in parallel with (i.e., during) the time gap / muting.

[0145] ​The UE 308 then continues the UL transmission using the corrected time-frequency (step 908). At some time thereafter, the UE 308 performs one or more actions (e.g., creates a time gap or silences as described above) to enable additional time-frequency compensation during the UL transmission (step 910). The UE 308 performs additional time-frequency correction (step 912), e.g., during the time period defined by the action(s) performed in step 910. The UE 308 then continues the UL transmission (step 914). The UE 308 can then continue this process until the UL transmission is complete.

[0146] Figure 10 further illustrates some aspects of embodiments of the present disclosure relating to creating a time gap or silencing the UL transmission to enable time-frequency compensation during the UL transmission. With respect to the gap / silence, two example scenarios are:

[0147] • Scenario 1 : As illustrated in Figure 10(a), silencing the last portion of the first portion of the UL transmission (signal) and advancing the beginning of the second portion of the UL transmission (signal). This can be viewed as creating a time gap by silencing the last portion of the first portion of the UL transmission. Thus, in this scenario, the UE can be viewed as performing the following two steps: (1) creating a time gap corresponding to the last portion of the first portion of the UL transmission by silencing the last portion of the first portion of the UL transmission, and (2) performing time-frequency compensation by shifting the beginning of the second portion of the UL transmission. Figure 7 A special case can be viewed as one in which the shifting of the beginning of the second portion of the UL transmission is such that the beginning of the second portion of the UL transmission is aligned with the beginning of the created time gap (i.e., with the beginning of the silenced portion of the first portion of the UL transmission).

[0148] • Scenario 2: Delaying the beginning of the second portion of the UL transmission. In other words, creating a time gap by delaying the beginning of the second portion of the UL transmission. So, in this scenario, the UE 308 can be viewed as performing the following two steps: (1) creating a time gap by delaying the beginning of the second portion of the UL transmission, and (2) performing time-frequency compensation by choosing the particular value for the delay of the beginning of the second portion of the UL transmission that gives the desired time-frequency compensation.

[0149] Figure 11is a schematic block diagram of a network node 1100 according to some embodiments of the present disclosure. The network node 1100 can be, for example, the base station component 306 or a combination of the satellite 302 and the base station component 306. As illustrated, the network node 1100 includes a control system 1102 that includes one or more processors 1104 (e.g., a central processing unit (CPU), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), and / or similar), memory 1106, and a network interface 1108. The one or more processors 1104 are also referred to herein as processing circuitry. In addition, the network node 1100 can also include one or more radio units 1110 that each include one or more transmitters 1112 and one or more receivers 1114 coupled to one or more antennas 1116. The radio unit(s) 1110 can be related to or part of radio interface circuitry. In some embodiments, the radio unit(s) 1110 are external to the control system 1102 and connected to the control system 1102 via, for example, a wired connection (e.g., an optical cable). However, in some other embodiments, the radio unit(s) 1110 and potentially the antenna(s) 1116 are integrated with the control system 1102. The one or more processors 1104 operate to provide one or more functions of the network node as described herein (e.g., one or more functions of the base station component 306, the combination of the satellite 302 and the base station component 306, as described herein). In some embodiments, the function(s) are implemented in software that is stored, for example, in the memory 1106 and is executable by the one or more processors 1104.

[0150] Figure 12is a schematic block diagram illustrating a virtualized embodiment of a network node 1100 according to some embodiments of the present disclosure. As used herein, a "virtualized" network node is an implementation of the network node 1100 in which at least a portion of the functionality of the network node 1100 (e.g., one or more functions of the base station

[0151] In this example, the functionality 1210 of the network node 1100 described herein (e.g., one or more functions of the base station component 306 or a combination of the satellite 302 and the base station component 306 as described herein) is implemented at the one or more processing nodes 1200 in any desired manner or distributed across the control system 1102 and the one or more processing nodes 1200. In some particular embodiments, some or all of the functionality 1210 of the network node 1100 described herein is implemented as virtual components executed by one or more virtual machines implemented in a virtual environment(s) hosted by the processing node(s) 1200. Notably, the control system 1102 can not be included in some embodiments, in which case the radio unit(s) 1110 (if included) can communicate directly with the processing node(s) 1200 via an appropriate network interface(s).

[0152] In some embodiments, a computer program including instructions which, when executed by at least one processor, causes the at least one processor to carry out the functionality of a network node 1100 or node (e.g., processing node 1200) implementing one or more of the functionality 1210 of the network node 1100 in a virtual environment according to any of the embodiments described herein is provided. In some embodiments, a carrier containing the aforementioned computer program product is provided. The carrier is one of an electronic signal, an optical signal, a radio signal, or a computer readable storage medium (e.g., a non-transitory computer readable medium such as memory).

[0153] Figure 13 is a schematic block diagram of a network node 1100 according to some other embodiments of the present disclosure. The network node 1100 includes one or more modules 1300, each of which is implemented in software. The module(s) 1300 provide the functionality of the network node 1100 described herein (e.g., one or more functions of the base station components 306, the satellite 302, and the combination of base station components 306 as described herein). This discussion is equally applicable to the processing node 1200 Figure 12 , where the modules 1300 can be implemented at one of the processing nodes 1200 or distributed across multiple processing nodes 1200 and / or distributed across the processing node(s) 1200 and the control system 1102.

[0154] Figure 14 is a schematic block diagram of a UE 1400 according to some embodiments of the present disclosure. The UE 1400 can be, for example, the UE 308. The UE 1400 is one example of a wireless communication device. As illustrated, the UE 1400 includes one or more processors 1402 (e.g., CPUs, ASICs, FPGAs, and / or the like), memory 1404, and one or more transceivers 1406 each including one or more transmitters 1408 and one or more receivers 1410 coupled to one or more antennas 1412. As will be appreciated by those skilled in the art, the transceiver(s) 1406 include Radio-Frequency (RF) front- end circuitry connected to the antenna(s) 1412 configured to condition signals communicated between the antenna(s) 1412 and the processor(s) 1402. The processor(s) 1402 are also referred to herein as processing circuitry. The transceiver(s) 1406 are also referred to herein as radio circuitry. In some embodiments, the functionality of the UE described above can be fully or partially implemented in software that is, for example, stored in the memory 1404 and is executed by the processor(s) 1402. Note that the UE 1400 can include additional components not illustrated Figure 14 in the diagram of FIG. 14 such as, for example, one or more user interface components (e.g., input / output interfaces including displays, buttons, touch-screens, microphones, speaker(s), and / or the like and / or any other components for allowing input of information into and / or output of information from the UE 1400), a power supply (e.g., a battery and associated power circuitry), etc.

[0155] In some embodiments, a computer program including instructions which, when executed by at least one processor, causes the at least one processor to carry out the functionality of a UE 1400 according to any of the embodiments described herein is provided. In some embodiments, a carrier containing the aforementioned computer program product is provided. The carrier is one of an electronic signal, an optical signal, a radio signal, or a computer readable storage medium (e.g., a non-transitory computer readable medium such as memory).

[0156] Figure 15 is a schematic block diagram of a UE 1400 according to some other embodiments of the disclosure. The UE 1400 includes one or more modules 1500, each of which is implemented in software as described herein. The module(s) 1500 provide the functionality of the UE as described herein.

[0157] Reference Figure 16 According to an embodiment, a communication system includes a telecommunication network 1600, such as a 3GPP-type cellular network, which comprises an access network 1602, such as a RAN, and a core network 1604. The access network 1602 comprises a plurality of base stations 1606A, 1606B, 1606C, such as Node Bs, eNBs, gNBs, or other types of wireless Access Points (APs), each defining a corresponding coverage area 1608A, 1608B, 1608C. Each base station 1606A, 1606B, 1606C is connectable to the core network 1604 over a wired or wireless connection 1610. A first UE 1612 located in coverage area 1608C is configured to wirelessly connect to, or be paged by, the corresponding base station 1606C. A second UE 1614 in coverage area 1608A is wirelessly connectable to the corresponding base station 1606A. While a plurality of UEs 1612, 1614 are illustrated in this example, the

[0158] The telecommunication network 1600 is itself connected to a host computer 1616, which can be embodied in the hardware and / or software of a standalone server, a cloud-implemented server, a distributed server, or a plurality of such servers. The host computer 1616 can provide the processing resources for hosting a website, for example. The connection 1618, 1620 between the telecommunication network 1600 and the host computer 1616 can be direct or indirect. The connection 1618, 1620 can be logical as well as physical. For example, the connection 1618, 1620 can be logical in that it does not consist of a direct physical connection. For example, the connection 1618, 1620 can pass through one or more intermediate networks. The intermediate network(s) can be under the control of the operator of the telecommunication network 1600 or of another operator. The connection 1618, 1620 can be a direct physical connection, i.e. it can not pass through a

[0159] Figure 16 The communication system as a whole enables connectivity between the connected UEs 1612, 1614 and the host computer 1616. The connectivity can be described as an over-the-top (OTT) connection 1624. The host computer 1616 and the connected UEs 1612, 1614 are configured to communicate data and / or signaling over the OTT connection 1624 using the access network 1602, the core network 1604, any intermediate network 1622, and possible further infrastructure (not shown) as

[0160] Reference will now be made to Figure 17An example implementation of the UE, base station and host according to embodiments discussed in the preceding paragraphs is described in the following with reference to Figure 17. In a communication system 1700, a host 1702 comprises hardware 1704 including a communication interface 1706 configured to set up and maintain a wired or wireless connection with an interface of a different communication device of the communication system 1700. The host 1702 further comprises processing circuitry 1708, which can have

[0161] storage and / or processing capabilities. In particular, the processing circuitry 1708 can comprise one or more programmable processors, ASICs, FPGAs, or combinations of these (not shown) adapted to execute instructions. The host 1702 further comprises software 1710, which is stored in or accessible by the host 1702 and executable by the processing circuitry 1708. The software 1710 includes a host application 1712. The host application 1712 can be operable to provide a service to a remote user such as a UE 1714 connecting via an OTT connection 1716 terminating at the UE 1714 and the host 1702. In providing the service to the remote user, the host application 1712 can provide user data which is transmitted using the OTT connection 1716. Figure 17 The communication system 1700 further includes a base station 1718 provided in a telecommunication system and comprising hardware 1720 enabling it to communicate with the host 1702 Figure 17 and with the UE 1714. The hardware 1720 can include a communication interface 1722 for

[0162] The communication system 1700 further includes the UE 1714 already referred to. The UE 1714 has hardware 1734 that can include a radio interface 1736 configured to set up and maintain a wireless connection 1726 with a base station serving a coverage area in which the UE 1714 currently is located. The hardware 1734 of the UE 1714 further includes processing circuitry 1738 which can comprise one or more programmable processors, ASICs, FPGAs, or combinations of these (not shown) adapted to execute software. The UE 1714 further includes software 1740 stored, in the UE 1714 or accessible by the UE 1714 from a storage medium (not shown) and executable by the processing circuitry 1738. The software 1740 includes client application 1742. The client application 1742 can be operable to provide a service to a human or non-human user via the UE 1714, with the support of the host computer 1702. In the host computer 1702, an executing host application 1712 can communicate with the executing client application 1742 via the OTT connection 1716 terminating at the UE 1714 and the host computer 1702. In providing the service to the user, the client application 1742 can receive request data from the host application 1712 and provide user data in response to the request data. The OTT connection 1716 can carry both the request data and the user data. The client application 1742 can interact with the user to generate the user data.

[0163] It is noted that Figure 17 the host computer 1702, the base station 1718, and the UE 1714 illustrated in Figure 16 may be similar or identical to the host computer 1616, one of the base stations 1606A, 1606B, 1606C, and one of the UEs 1612, 1614 of Figure 17 , respectively. That is, the inner workings of these entities can be as shown in Figure 16 , and independently, the surrounding network topology can be that of .

[0164] In Figure 17 , the OTT connection 1716 has been drawn abstractly to illustrate the communication between the host computer 1702 and the UE 1714 via the base station 1718 without explicit reference to any intermediary devices and the precise routing of messages via these devices. Network infrastructure can determine the routing, which can be configured to hide from the UE 1714 or from the service provider operating the host computer 1702, or both. While the OTT connection 1716 is active, the network infrastructure can further take decisions that dynamically change the routing (e.g., based on configuration changes in the network infrastructure or load-balancing considerations).

[0165] The wireless connection 1726 between the UE 1714 and the base station 1718 is in accordance with the teachings of the embodiments described throughout this disclosure. One or more of the various embodiments improve the performance of OTT services provided to the UE 1714 using the OTT connection 1716, in which the wireless connection 1726 forms the last segment.

[0166] A measurement procedure can be implemented for the purpose of monitoring the data rate, latency, and other factors on which the one or more embodiments improve. There can further be an optional network functionality to reconfigure the OTT connection 1716 between the host 1702 and the UE 1714, in response to variations in the measurement results. The measurement procedure and / or the network functionality to reconfigure the OTT connection 1716 can be implemented in the software 1710 and the hardware 1704 of the host 1702 or in the software 1740 and the hardware 1734 of the UE 1714, or both. In some embodiments, sensors (not shown) can be deployed in or in association with the communication devices through which the OTT connection 1716 passes; the sensors can participate in the measurement procedure by providing values of the monitored quantities exemplified above, or values of other physical quantities from which the software 1710, 1740 can compute or estimate the monitored quantities. The reconfiguring of the OTT connection 1716 can include message format, retransmission settings, preferred routing etc.; the reconfiguring need not affect the base station 1718, and it can be unknown or unnoticed by the base station 1718. Such procedures and functionalities can be known and implemented in the art. In certain embodiments, the measurements can involve proprietary UE signaling facilitating the host 1702's measurements of throughput, propagation times, latency, and the like. The measurements can be implemented due to the software 1710, 1740 using the OTT connection 1716 to cause messages to be passed, in particular empty messages or "dummy" messages, while the software 1710, 1740 monitors propagation times, errors etc.

[0167] Figure 18 is a flowchart illustrating a method implemented in a communication system in accordance with one embodiment. The communication system includes a host computer, a base station and a UE which can be those described with reference to Figure 16 and Figure 17 Fig. 16. For simplicity of the present disclosure, in this part only the steps relevant for understanding the UE's distribution of the load information will be included. Further details about the method of distributing load information can be found in the description related to Fig. 16. Figure 18Figure. In step 1800, the host provides user data. In sub-step 1802 (which can be optional) of step 1800, the host provides the user data by executing a host application. In step 1804, the host initiates a transmission to the UE that carries the user data. In step 1806 (which can be optional), the base station communicates the user data carried in the transmission initiated by the host to the UE, in accordance with the teachings of embodiments described throughout this disclosure. In step 1808 (which can also be optional), the UE executes a client application associated with the host application executed by the host.

[0168] Figure 19 Figure. In step 1800, the host provides user data. In sub-step 1802 (which can be optional) of step 1800, the host provides the user data by executing a host application. In step 1804, the host initiates a transmission to the UE that carries the user data. In step 1806 (which can be optional), the base station communicates the user data carried in the transmission initiated by the host to the UE, in accordance with the teachings of embodiments described throughout this disclosure. In step 1808 (which can also be optional), the UE executes a client application associated with the host application executed by the host. Figure 16 and Figure 17 Figure. In step 1800, the host provides user data. In sub-step 1802 (which can be optional) of step 1800, the host provides the user data by executing a host application. In step 1804, the host initiates a transmission to the UE that carries the user data. In step 1806 (which can be optional), the base station communicates the user data carried in the transmission initiated by the host to the UE, in accordance with the teachings of embodiments described throughout this disclosure. In step 1808 (which can also be optional), the UE executes a client application associated with the host application executed by the host. Figure 19 Figure. In step 1800, the host provides user data. In sub-step 1802 (which can be optional) of step 1800, the host provides the user data by executing a host application. In step 1804, the host initiates a transmission to the UE that carries the user data. In step 1806 (which can be optional), the base station communicates the user data carried in the transmission initiated by the host to the UE, in accordance with the teachings of embodiments described throughout this disclosure. In step 1808 (which can also be optional), the UE executes a client application associated with the host application executed by the host.

[0169] Figure 20 Figure. In step 1800, the host provides user data. In sub-step 1802 (which can be optional) of step 1800, the host provides the user data by executing a host application. In step 1804, the host initiates a transmission to the UE that carries the user data. In step 1806 (which can be optional), the base station communicates the user data carried in the transmission initiated by the host to the UE, in accordance with the teachings of embodiments described throughout this disclosure. In step 1808 (which can also be optional), the UE executes a client application associated with the host application executed by the host. Figure 16 and Figure 17 Figure. In step 1800, the host provides user data. In sub-step 1802 (which can be optional) of step 1800, the host provides the user data by executing a host application. In step 1804, the host initiates a transmission to the UE that carries the user data. In step 1806 (which can be optional), the base station communicates the user data carried in the transmission initiated by the host to the UE, in accordance with the teachings of embodiments described throughout this disclosure. In step 1808 (which can also be optional), the UE executes a client application associated with the host application executed by the host. Figure 20 Figure. In step 1800, the host provides user data. In sub-step 1802 (which can be optional) of step 1800, the host provides the user data by executing a host application. In step 1804, the host initiates a transmission to the UE that carries the user data. In step 1806 (which can be optional), the base station communicates the user data carried in the transmission initiated by the host to the UE, in accordance with the teachings of embodiments described throughout this disclosure. In step 1808 (which can also be optional), the UE executes a client application associated with the host application executed by the host.

[0170] Figure 21 is a flowchart illustrating a method implemented in a communication system according to an embodiment. The communication system includes a host computer, a base station and a UE which can be those described with reference to Figure 16 and Figure 17 The description that follows will only include the figures referenced Figure 21 for simplicity of the present disclosure. In step 2100, which can be optional, the base station receives user data from the UE, according to the teachings of the embodiments described throughout this disclosure. In step 2102, which can be optional, the base station initiates transmission of the received user data to the host computer. In step 2104, which can be optional, the host computer receives the user data carried in the transmission initiated by the base station.

[0171] Any appropriate steps, methods, features, functions, or benefits disclosed herein can be performed through one or more functional units or modules of one or more virtual apparatuses. Each virtual apparatus can comprise a number of these functional units. These functional units can be implemented by processing circuitry, which can include one or more microprocessor or microcontrollers, as well as other digital hardware, which can include digital signal processors (DSPs), special-purpose computer chips, etc. The processing circuitry can be configured to execute program code stored in memory, which can include one or several types of memory such as read-only memory (ROM), random-access memory (RAM), cache memory, flash memory devices, optical storage devices, etc. Program code stored in memory includes program instructions for executing a telecommunications and / or data communications protocol and program instructions for carrying out one or more of the techniques described herein. In some implementations, the processing circuitry can be used to cause the respective functional unit(s) to perform corresponding functions according to one or more embodiments of the present disclosure.

[0172] Although the processes in the figures can show a particular order of operations, it is understood that the order of operations can differ from what is depicted. For example, certain operations can be performed in a different order, omitted, or combined with other operations, etc.

[0173] Some example embodiments of the present disclosure are as follows:

[0174] Group A Embodiments

[0175] Embodiment 1 : A method performed by a wireless communication device, the method comprising:

[0176] • initiating (902) an uplink transmission;

[0177] • performing (904) an action(s), the action(s) comprising:

[0178] o creating a time gap within the uplink transmission; and / or

[0179] o muting a portion of the uplink transmission to support a timing advance of a continued uplink transmission;

[0180] • performing (906) the time-frequency compensation; and

[0181] • continuing (908) the uplink transmission after performing the time-frequency compensation.

[0182] Embodiment 2: The method as in embodiment 1, wherein performing (906) the time- frequency compensation comprises performing (906) the time-frequency compensation such that a time and / or frequency compensation is applied at the wireless communication device during a time period created by performing the action(s).

[0183] Embodiment 3: The method as in embodiment 1 or 2, wherein the uplink transmission comprises a plurality of consecutive repetitions of a base transmission.

[0184] Embodiment 4: The method as in embodiment 1 or 2, wherein the uplink transmission consists of a plurality of consecutive repetitions of a base transmission.

[0185] Embodiment 5: The method as in embodiment 3 or 4, wherein the uplink transmission is a NB-IoT or LTE uplink transmission comprising a plurality of consecutive repetitions of a base transmission.

[0186] Embodiment 6: The method as in any one of embodiments 3 to 5, wherein the uplink transmission is a NB-IoT or LTE-M uplink transmission comprising a plurality of consecutive repetitions of a base transmission.

[0187] Embodiment 7: The method as in any one of embodiments 3 to 6, wherein the base transmission is a narrowband physical uplink shared channel, NPUSCH.

[0188] Embodiment 8: The method as in any one of embodiments 3 to 6, wherein the base transmission is a physical uplink shared channel, PUSCH, transmission.

[0189] Embodiment 9: The method as in any one of embodiments 1 to 8, wherein the action(s) comprise creating (904) a time gap within the uplink transmission.

[0190] Embodiment 10: The method as in embodiment 9, wherein creating (904) a time gap within the uplink transmission comprises creating (904) a time gap within a transmission time interval (TTI) of the uplink transmission.

[0191] Embodiment 11: The method of embodiment 10, wherein the TTI has a length greater than 1 subframe, and / or greater than 1 radio frame, and / or greater than 1 ms, and / or greater than 10 ms, and / or greater than 1 second.

[0192] Embodiment 12: The method of any of embodiments 1 to 11, wherein performing (906) the time-frequency compensation comprises: (a) performing one or more actions to compensate for an estimated Doppler shift caused, e.g., by motion of a satellite of a satellite-based radio access network that is to receive the uplink transmission; and / or (b) performing one or more actions to compensate for an estimated time dilation caused, e.g., by motion of a satellite of a satellite-based radio access network that is to receive the uplink transmission.

[0193] Embodiment 13: The method of any of embodiments 1 to 12, wherein performing (906) the time-frequency compensation comprises adjusting a transmission frequency of the continued uplink transmission.

[0194] Embodiment 14: The method of embodiment 13, wherein the adjustment of the transmission frequency is performed to compensate for an estimated Doppler shift and / or a change in the estimated Doppler shift caused, e.g., by motion of a satellite of a satellite-based radio access network that is to receive the uplink transmission.

[0195] Embodiment 15: The method of any of embodiments 1 to 14, wherein performing (906) the time-frequency compensation comprises adjusting a time resolution and / or a sampling rate of the continued uplink transmission.

[0196] Embodiment 16: The method of embodiment 15, wherein the adjustment of the time resolution and / or the sampling rate is performed to compensate for an estimated time dilation and / or a change in the estimated time dilation caused, e.g., by motion of a satellite of a satellite-based radio access network that is to receive the uplink transmission.

[0197] Embodiment 17: The method of any of embodiments 15 to 16, wherein the adjustment of the time resolution and / or the sampling rate stretches or compresses the continued transmission in the time domain.

[0198] Embodiment 18: The method of any of embodiments 1 to 17, wherein performing (906) the time-frequency compensation comprises adjusting an uplink transmission timing (e.g., timing advance) of the wireless communication device.

[0199] Embodiment 19: The method of embodiment 18, wherein the adjustment of the uplink transmission timing is performed to compensate for an estimated time dilation and / or a change in the estimated time dilation caused, e.g., by motion of a satellite of a satellite-based radio access network that is to receive the uplink transmission.

[0200] Embodiment 20: The method of any one of Embodiments 1 to 19 wherein performing (906) the time-frequency compensation comprises shifting a starting point of a remaining portion of the uplink transmission.

[0201] Embodiment 21 : The method of Embodiment 20 wherein the shifting of the starting point is performed to compensate for an estimated time dilation and / or a change in the estimated time dilation caused, for example, by motion of a satellite of a satellite-based radio access network that is to receive the uplink transmission.

[0202] Embodiment 22: The method of any one of Embodiments 1 to 21 further comprising receiving (900) from a network node a configuration of one or more parameters defining a position of the time gap(s) to be created in the uplink transmission or one or more values to be used by the wireless communication device to derive a position of the time gap(s) to be created in the uplink transmission.

[0203] Embodiment 23: The method of any one of Embodiments 1 to 21 further comprising receiving (900) from a network node a configuration of one or more parameters defining when to perform the time-frequency compensation or one or more values to be used by the wireless communication device to derive when to perform the time-frequency compensation.

[0204] Embodiment 24: The method of any one of Embodiments 1 to 23 wherein creating the time gap comprises: delaying a portion of the uplink transmission; and / or muting a portion of the uplink transmission; and / or puncturing a portion of the uplink transmission; and / or dropping one or more symbols of the uplink transmission; and / or not using one or more symbols of the uplink transmission; and / or blanking out one or more symbols of the uplink transmission.

[0205] Embodiment 25: The method of any of the preceding embodiments further comprising: providing user data; and forwarding the user data to a host via a transmission to a base station.

[0206] Group B Embodiments

[0207] Embodiment 26: A method performed by a network node (e.g., a base station), the method comprising configuring (900) a wireless communication device with one or more parameters that either: define a position of one or more time gaps to be used by the wireless communication device to perform time-frequency compensation during an uplink transmission; or define one or more values to be used by the wireless communication device to derive a position of one or more time gaps to be used by the wireless communication device to perform time-frequency compensation during an uplink transmission.

[0208] Example 27: A method performed by a network node (e.g., a base station), the method comprising: configuring (900) a wireless communication device with one or more parameters that either: define when time-frequency compensation is performed during an uplink transmission; or define one or more values to be used by the wireless communication device to derive when time-frequency compensation is performed during an uplink transmission.

[0209] Example 28: The method of Example 26 or 27, wherein the uplink transmission comprises a plurality of consecutive repetitions of a base transmission.

[0210] Example 29: The method of Example 26 or 27, wherein the uplink transmission consists of a plurality of consecutive repetitions of a base transmission.

[0211] Example 30: The method of Example 28 or 29, wherein the uplink transmission is an NB-IoT or LTE uplink transmission comprising a plurality of consecutive repetitions of a base transmission.

[0212] Example 31: The method of Example 28 or 29, wherein the uplink transmission is an NB-IoT or LTE-M uplink transmission comprising a plurality of consecutive repetitions of a base transmission.

[0213] Example 32: The method of any of Examples 28-31, wherein the base transmission is a narrowband physical uplink shared channel, NPUSCH.

[0214] Example 33: The method of any of Examples 28-31, wherein the base transmission is a physical uplink shared channel, NPUSCH.

[0215] Example 34: The method of any of Examples 26-33, wherein one or more time gaps are created within a TTI of the uplink transmission.

[0216] Example 35: The method of Example 34, wherein the TTI has a length that is greater than 1 subframe, and / or greater than 1 radio frame, and / or greater than 1 ms, and / or greater than 10 ms, and / or greater than 1 second.

[0217] Example 36: The method of any of Examples 26-35, wherein the location of the time gap(s) and / or when time-frequency compensation is to be performed by the wireless communication device is determined based on satellite ephemeris and / or a cyclic prefix duration (e.g., by the base station or another network node or system).

[0218] Example 37: The method of any of the preceding Examples, further comprising: obtaining user data; and forwarding the user data to a host or a wireless device.

[0219] Group C Implementation Examples

[0220] Example 38: A wireless device includes: a processing circuit configured to perform any step of any embodiment in any of the Group A examples; and a power supply circuit configured to power the wireless device.

[0221] Example 39: A base station includes: processing circuitry configured to perform any step of any embodiment in any of the examples in Group B; and power supply circuitry configured to power the base station.

[0222] Example 40: A user equipment (UE) includes: an antenna configured to transmit and receive wireless signals; a radio front-end circuit connected to the antenna and to a processing circuit and configured to regulate signals transmitted between the antenna and the processing circuit; a processing circuit configured to perform any step of any embodiment in any of the Group A examples; an input interface connected to the processing circuit and configured to allow information to be processed by the processing circuit to be input into the UE; an output interface connected to the processing circuit and configured to output information processed by the processing circuit from the UE; and a battery connected to the processing circuit and configured to power the UE.

[0223] Example 41; A communication system includes a host, the host comprising: processing circuitry configured to provide user data; and a communication interface configured to forward the user data to a cellular network for transmission to a user equipment (UE); wherein the cellular network includes a base station having a radio interface and processing circuitry, the processing circuitry of the base station being configured to perform any step of any of the steps in any of the embodiments in Group B examples.

[0224] Example 42: The communication system as described in the preceding examples further includes a base station.

[0225] Example 43: The communication system as described in the preceding two examples further includes a UE, wherein the UE is configured to communicate with a base station.

[0226] Example 44: A communication system as described in the preceding three examples, wherein: the host's processing circuitry is configured to execute a host application to provide user data; and the UE includes processing circuitry configured to execute a client application associated with the host application.

[0227] Example 45: A method implemented in a communication system, the communication system including a host, a base station, and a user equipment (UE), the method comprising: providing user data at the host; and initiating a transmission carrying the user data from the host to the UE via a cellular network including the base station, wherein the base station performs any step of any of the steps in any of the embodiments in Group B.

[0228] Embodiment 46: A method as in any of the preceding embodiments, further comprising transmitting user data at the base station.

[0229] Embodiment 47: A method as in any of the 2 preceding embodiments, wherein the user data is provided at the host by executing a host application, the method further comprising executing a client application associated with the host application at the UE.

[0230] Embodiment 48: A user equipment, UE, configured to communicate with a base station, the UE comprising a radio interface and processing circuitry configured to perform the method of any of the 3 preceding embodiments.

[0231] Embodiment 49: A communication system including a host, the host comprising: processing circuitry configured to provide user data; and a communication interface configured to forward the user data to a cellular network for transmission to a user equipment, UE; wherein the UE comprises a radio interface and processing circuitry, the components of the UE being configured to perform any of the steps of any of the embodiments of Group A.

[0232] Embodiment 50: A communication system as in any of the preceding embodiments, wherein the cellular network further comprises a base station configured to communicate with the UE.

[0233] Embodiment 51: A communication system as in any of the 2 preceding embodiments, wherein: the processing circuitry of the host is configured to execute a host application, thereby providing the user data; and the processing circuitry of the UE is configured to execute a client application associated with the host application.

[0234] Embodiment 52: A method implemented in a communication system including a host, a base station, and a user equipment, UE, the method comprising: providing user data at the host; and initiating, at the host, a transmission of the user data to the UE via a cellular network comprising the base station, wherein the UE performs any of the steps of any of the embodiments of Group A.

[0235] Embodiment 53: A method as in any of the preceding embodiments, further comprising receiving the user data at the UE from the base station.

[0236] Embodiment 54: A communication system including a host, the host comprising: a communication interface configured to receive user data originating from a transmission from a user equipment, UE, to a base station; wherein the UE comprises a radio interface and processing circuitry, the processing circuitry of the UE being configured to perform any of the steps of any of the embodiments of Group A.

[0237] Embodiment 55: A communication system as in any of the preceding embodiments, further comprising the UE.

[0238] Embodiment 56: A communication system as in any of the preceding 2 embodiments, further including a base station, wherein the base station includes a radio interface configured to communicate with the UE and a communication interface configured to forward user data carried by transmissions from the UE to the base station to the host.

[0239] Embodiment 57: A communication system as in any of the preceding 3 embodiments, wherein: the processing circuitry of the host is configured to execute a host application; and the processing circuitry of the UE is configured to execute a client application associated with the host application, thereby to provide the user data.

[0240] Embodiment 58: A communication system as in any of the preceding 4 embodiments, wherein: the processing circuitry of the host is configured to execute a host application, thereby to provide request data; and the processing circuitry of the UE is configured to execute a client application associated with the host application, thereby to provide the user data in response to the request data.

[0241] Embodiment 59: A method implemented in a communication system including a host, a base station and a user equipment, UE, the method comprising: receiving, at the host, user data transmitted from the UE to the base station, wherein the UE performs any of the steps of any of the Group A embodiments.

[0242] Embodiment 60: A method as in any of the preceding embodiments, further comprising providing, at the UE, the user data to the base station.

[0243] Embodiment 61 : A method as in any of the preceding 2 embodiments, further comprising: executing, at the UE, a client application, thereby to provide the user data to be transmitted; and executing, at the host, a host application associated with the client application.

[0244] Embodiment 62: A method as in any of the preceding 3 embodiments, further comprising: executing, at the UE, a client application; and receiving, at the UE, input data to the client application, the input data being provided at the host by executing a host application associated with the client application; wherein the user data to be transmitted is provided by the client application in response to the input data.

[0245] Embodiment 63: A communication system including a host, the host including a communication interface configured to receive user data originating from transmissions from a user equipment, UE, to a base station, wherein the base station includes a radio interface and processing circuitry, the processing circuitry of the base station being configured to perform any of the steps of any of the Group B embodiments.

[0246] Embodiment 64: A communication system as in any of the preceding embodiments, further including a base station.

[0247] Embodiment 65: The communication system of the preceding 2 embodiments, further including the UE, wherein the UE is configured to communicate with the base station.

[0248] Embodiment 66: The communication system of the preceding 3 embodiments, wherein: the processing circuitry of the host is configured to execute the host application; and the UE is configured to execute a client application associated with the host application, thereby to provide user data to be received by the host.

[0249] Embodiment 67: A method implemented in a communication system including a host computer, a base station and a user equipment UE, the method comprising: receiving, at the host computer, from the base station, user data originating from transmissions received by the base station from the UE, wherein the UE performs any of the steps of any of the Group A embodiments.

[0250] Embodiment 68: The method of the preceding embodiment, further comprising receiving, at the base station, user data from the UE.

[0251] Embodiment 69: The method of the preceding 2 embodiments, further comprising initiating, at the base station, transmission of the received user data to the host computer.

[0252] At least some of the following abbreviations can be used in the present disclosure. If there is any inconsistency between the above and what is used in the disclosure, the above should prevail. If an abbreviation is listed multiple times, the first time it is listed should prevail over any subsequent listing(s).

[0253] • 3GPP Third Generation Partnership Project

[0254] • 5G Fifth Generation

[0255] • 5GC Fifth Generation Core Network

[0256] • 5GS Fifth Generation System

[0257] • AMF Access and Mobility Function

[0258] • AP Access Point

[0259] • ASIC Application-Specific Integrated Circuit

[0260] • AUSF Authentication Server Function

[0261] • BL Bandwidth Reduced Low Complexity

[0262] • CE Coverage Enhancement

[0263] • CP Cyclic Prefix

[0264] • CPU Central Processing Unit

[0265] • DCI Downlink Control Information

[0266] • DL Downlink

[0267] • DSP Digital Signal Processor

[0268] • eMBB Enhanced Mobile Broadband

[0269] • eNB Enhanced or Evolved Node B

[0270] • EPC Evolved Packet Core

[0271] • EPS Evolved Packet System

[0272] • FDD Frequency Division Duplex

[0273] • FPGA Field Programmable Gate Array

[0274] • GEO Geosynchronous Earth Orbit

[0275] • GHz Gigahertz

[0276] • gNB New Radio Base Station

[0277] • gNB-CU New Radio Base Station Central Unit

[0278] • gNB-DU New Radio Base Station Distributed Unit

[0279] • HSS Home Subscriber Server

[0280] • IoT Internet of Things

[0281] • kHz Kilohertz

[0282] • km Kilometer

[0283] • km / s Kilometers per second

[0284] • LEO Low Earth Orbit

[0285] • LTE Long Term Evolution

[0286] • LTE-M Long Term Evolution for Machine Type Communication

[0287] • MAC Medium Access Control

[0288] • MAC-CE Medium Access Control Control Element

[0289] • MBB Mobile Broadband

[0290] • MEO Medium Earth Orbit

[0291] • MME mobility management entity

[0292] • mMTC massive machine type communications

[0293] • ms millisecond

[0294] • MTC machine type communications

[0295] • NB-IoT narrow band internet of things

[0296] • NEF network exposure function

[0297] • NF network function

[0298] • NPUSCH narrowband physical uplink shared channel

[0299] • NR new radio

[0300] • NRF network function repository function

[0301] • NSSF network slice selection function

[0302] • NTN non-terrestrial network

[0303] • NW network

[0304] • OTT over the top

[0305] • PC personal computer

[0306] • PCF policy control function

[0307] • P-GW packet data network gateway

[0308] • ppm parts per million

[0309] • ppm / s parts per million per second

[0310] • PRACH physical random access channel

[0311] • PSS primary synchronization signal

[0312] • PUCCH physical uplink control channel

[0313] • PUSCH physical uplink shared channel

[0314] • RAM random access memory

[0315] • RAN radio access network

[0316] • RAR random access response

[0317] • RAT Radio Access Technology

[0318] • ROM Read Only Memory

[0319] • RRC Radio Resource Control

[0320] • RX Receive

[0321] • SCEF Network Exposure Function

[0322] • SCS Subcarrier Spacing

[0323] • SMF Session Management Function

[0324] • SSS Secondary Synchronization Signal

[0325] • TA Timing Advance

[0326] • TDD Time Division Duplex

[0327] • TR Technical Report

[0328] • TTI Transmission Time Interval

[0329] • TX Transmit

[0330] • UDM Unified Data Management

[0331] • UE User Equipment

[0332] • UL Uplink

[0333] • UPF User Plane Function

[0334] • URLLC Ultra-Reliable and Low-Latency Communication

[0335] Those skilled in the art will recognize improvements and modifications to the embodiments of the present disclosure. All such improvements and modifications are intended to be within the scope of the concepts disclosed herein.

[0336] References:

[0337] [1] TR 38.811, Study on New Radio (NR) to support non-terrestrial networks

[0338] [2] TR 38.821, Solutions for NR to support non-terrestrial networks

[0339] [3] RP-193234, Solutions for NR to support non-terrestrial networks (NTN), 3GPP RAN#86

[0340] [4] RP-193235, Study on NB-IoT / eMTC support for Non-Terrestrial Network, 3GPP RAN#86

[0341] [5] R1-1912725, On NTN synchronization, random access and timing advance, Ericsson, 3GPP RAN1#99

[0342] [6] 3GPP TS 36.211 v16.0.0

Claims

1. A method performed by a wireless communication device (308), the method comprising: Configuration of one or more parameters received (900) from a network node (306) of a non-terrestrial network (NTN) (300), the one or more parameters defining the location of a time gap to be created in the uplink transmission or to be used by the wireless communication device to derive one or more values ​​of the location of the time gap to be created in the uplink transmission; The uplink transmission begins (902); Create the time gap (904) within the uplink transmission; The (906) action is performed during the time interval; and After performing the aforementioned action, the uplink transmission continues (908). The actions include adjusting the transmission frequency of the continued uplink transmission and / or adjusting the uplink transmission timing of the wireless communication device.

2. The method as described in claim 1, wherein, The uplink transmission includes multiple consecutive repetitions of the transmission.

3. The method as described in claim 1, wherein, The uplink transmission consists of multiple consecutive repetitions of transmission.

4. The method of claim 1, wherein, The uplink transmission includes multiple consecutive, repeating narrowband Internet of Things (NB-IoT) or Long Term Evolution (LTE) LTE-M uplink transmissions for Machine Type Communication (MTC).

5. The method as claimed in any one of claims 2 to 4, wherein, The uplink transmission is an NB-IoT or LTE-M uplink transmission consisting of multiple consecutive repetitions of transmission.

6. The method as claimed in any one of claims 2 to 4, wherein, The uplink transmission is the Narrowband Physical Uplink Shared Channel (NPUSCH).

7. The method as claimed in any one of claims 2 to 4, wherein, The uplink transmission is the Physical Uplink Shared Channel (PUSCH).

8. The method of claim 1, wherein, The time gap (904) created within the uplink transmission includes the time gap (904) created within the transmission time interval (TTI) of the uplink transmission.

9. The method of claim 8, wherein, The TTI has a length of more than one subframe or more than one millisecond.

10. The method as claimed in any one of claims 1 to 4, wherein, Performing the action described in (906) includes: Step a: Perform one or more actions to compensate for the estimated Doppler shift associated with the uplink transmission; or Step b: Perform one or more actions to compensate for the estimated time dilation associated with the uplink transmission; or Step c: Both steps a and b.

11. The method as claimed in any one of claims 1 to 4, wherein, Performing the action described in (906) includes: Step a: Perform one or more actions to compensate for the estimated Doppler shift caused by the motion of satellites in the satellite-based radio access network that are to receive the uplink transmission; or Step b: Perform one or more actions to compensate for the estimated time dilation caused by the motion of satellites in the satellite-based radio access network that are to receive the uplink transmissions; or Step c: Both steps a and b.

12. The method of claim 1, wherein, The adjustment of the transmission frequency is performed to compensate for the estimated Doppler shift or changes in the estimated Doppler shift associated with the uplink transmission.

13. The method as claimed in any one of claims 1 to 4, wherein, Performing the action (906) includes adjusting the time resolution, sampling rate, or both of the time resolution and sampling rate of the continued uplink transmission.

14. The method of claim 13, wherein, Adjustments are made to the time resolution, the sampling rate, or both the time resolution and the sampling rate to compensate for the estimated time dilation or variations in the estimated time dilation associated with the uplink transmission.

15. The method of claim 13, wherein, Adjusting the time resolution, the sampling rate, or both the time resolution and the sampling rate prolongs or compresses the continued transmission in the time domain.

16. The method of claim 1, wherein, Adjustments are made to the uplink transmission timing to compensate for estimated time dilation or variations in estimated time dilation associated with the uplink transmission.

17. The method as claimed in any one of claims 1 to 4, wherein, Performing the action described in (906) includes shifting the starting point of the remaining portion of the uplink transmission transmitted by continuing the uplink transmission described in (908).

18. The method of claim 17, wherein, The process involves shifting the starting point to compensate for the estimated time dilation or variations in the estimated time dilation associated with the uplink transmission.

19. The method of any one of claims 1 to 4, further comprising receiving (900) a configuration of one or more parameters from a network node, the one or more parameters defining when the action is performed or to be used by the wireless communication device to derive one or more values ​​when the action is performed.

20. The method as claimed in any one of claims 1 to 4, wherein, Creating the time gap includes: ● Delay a portion of the uplink transmission; and / or ●Silence a portion of the uplink transmission; and / or ● Punch a portion of the uplink transmission; and / or ● Discard one or more symbols of the uplink transmission; and / or ● Do not use one or more symbols of the aforementioned uplink transmission; and / or ●Leave one or more symbols in the uplink transmission blank.

21. The method as claimed in any one of claims 1 to 4, wherein, The location of the one or more time gaps is based on satellite ephemeris and / or cycle prefix duration.

22. A wireless communication device (308), comprising: One or more transmitters (1408); One or more receivers (1410); as well as A processing circuit (1402) associated with the one or more transmitters (1408) and the one or more receivers (1410), the processing circuit (1402) being configured to cause the wireless communication device (308) to: Configuration of one or more parameters received (900) from a network node (306) of a non-terrestrial network (NTN) (300), the one or more parameters defining the location of a time gap to be created in the uplink transmission or to be used by the wireless communication device to derive one or more values ​​of the location of the time gap to be created in the uplink transmission; The uplink transmission begins (902); Create the time gap (904) within the uplink transmission; The (906) action is performed during the time interval; and After performing the aforementioned action, the uplink transmission continues (908). The actions include adjusting the transmission frequency of the continued uplink transmission and / or adjusting the uplink transmission timing of the wireless communication device.

23. The wireless communication device (308) as claimed in claim 22, wherein, The processing circuit (1402) is further configured to cause the wireless communication device (308) to perform the method as described in any one of claims 2 to 21.

24. A computer program product comprising instructions that, when executed on at least one processor, cause the at least one processor to perform the method according to any one of claims 1 to 21.

25. A non-transitory computer-readable medium storing instructions executable by processing circuitry of a wireless communication device, wherein the wireless communication device is operable to: Configuration of one or more parameters received (900) from a network node (306) of a non-terrestrial network (NTN) (300), the one or more parameters defining the location of a time gap to be created in the uplink transmission or to be used by the wireless communication device to derive one or more values ​​of the location of the time gap to be created in the uplink transmission; The uplink transmission begins (902); Create the time gap (904) within the uplink transmission; The (906) action is performed during the time interval; and After performing the aforementioned action, the uplink transmission continues (908). The actions include adjusting the transmission frequency of the continued uplink transmission and / or adjusting the uplink transmission timing of the wireless communication device.

26. A method performed by a network node (306) of a non-terrestrial network NTN (300), the method comprising: The wireless communication device (304) is configured using one or more parameters, wherein the one or more parameters are: Define the position of the time interval during uplink transmission to be used by the wireless communication device (304) to perform time compensation, frequency compensation, or both time compensation and frequency compensation; or Define one or more values ​​of the position of the time interval to be used by the wireless communication device (304) to derive the position of the time interval to be used by the wireless communication device (304) to perform time compensation, frequency compensation, or both time compensation and frequency compensation during the uplink transmission.

27. The method of claim 26, wherein, The uplink transmission includes multiple consecutive repetitions of the transmission.

28. The method of claim 26, wherein, The uplink transmission consists of multiple consecutive repetitions of transmission.

29. The method of claim 26, wherein, The uplink transmission includes multiple consecutive, repetitive narrowband Internet of Things (NB-IoT) or Long Term Evolution (LTE) Machine Type Communication (MTC) LTE-M uplink transmissions.

30. The method of claim 26, wherein, The uplink transmission is a narrowband Internet of Things (NB-IoT) or Long Term Evolution (LTE) Machine Type Communication (MTC) LTE-M uplink transmission consisting of multiple consecutive repetitions of transmission.

31. The method according to any one of claims 27 to 30, wherein, The uplink transmission is the Narrowband Physical Uplink Shared Channel (NPUSCH).

32. The method of any one of claims 27 to 30, wherein, The uplink transmission is the Physical Uplink Shared Channel (PUSCH).

33. The method of any one of claims 26 to 30, wherein, The time gap is created within the transmission time interval (TTI) of the uplink transmission.

34. The method of claim 33, wherein, The TTI has a length of more than one subframe or more than one millisecond.

35. The method of any one of claims 26 to 30, wherein: The location of the time gap is based on satellite ephemeris and / or the duration of the cyclic prefix; or The timing of the time compensation, the frequency compensation, or both time compensation and frequency compensation to be performed by the wireless communication device (304) is based on one or more locations of satellite ephemeris and / or cyclic prefix duration.

36. A network node (306; 1100) of a non-terrestrial network NTN (300), comprising: Processing circuits (1104; 1304) are configured to cause the network node (306): The wireless communication device (304) is configured using one or more parameters, wherein the one or more parameters are: Define the position of the time interval during uplink transmission to be used by the wireless communication device (304) to perform time compensation, frequency compensation, or both time compensation and frequency compensation; or Define one or more values ​​of the position of the time interval to be used by the wireless communication device (304) to derive the position of the time interval to be used by the wireless communication device (304) to perform time compensation, frequency compensation, or both time compensation and frequency compensation during the uplink transmission.

37. The network node (306) as described in claim 36, wherein, The network node (306) is further adapted to perform the method as described in any one of claims 26 to 35.

38. A computer program product comprising instructions that, when executed on at least one processor, cause the at least one processor to perform the method according to any one of claims 26 to 35.

39. A non-transitory computer-readable medium storing instructions executable by processing circuitry of a network node, wherein the network node is operable to: The wireless communication device (304) is configured using one or more parameters, wherein the one or more parameters are: Define the position of the time interval during uplink transmission to be used by the wireless communication device (304) to perform time compensation, frequency compensation, or both time compensation and frequency compensation; or Define one or more values ​​of the position of the time interval to be used by the wireless communication device (304) to derive the position of the time interval to be used by the wireless communication device (304) to perform time compensation, frequency compensation, or both time compensation and frequency compensation during the uplink transmission.

Images