Patent Application
20240146401
This application is based on and claims priority under 35 U.S.C. § 119 to Korean Patent Application No. 10-2022-0140764, filed on Oct. 27, 2022, in the Korean Intellectual Property Office, the disclosure of which is incorporated by reference herein in its entirety.
The present disclosure generally relates to a non-terrestrial network (NTN), and more specifically, to an electronic device and a method for compensating Doppler shift in the non-terrestrial network.
A non-terrestrial network (NTN) has been introduced to complement a terrestrial network that provides a wireless communication system. The non-terrestrial network may provide a communication service even in areas where construction of the terrestrial network is difficult or in disaster situations. In addition, an access network environment may be provided efficiently due to the recent decrease in satellite launch costs.
In embodiments, a method performed by a user equipment (UE) may comprise performing a compensation for doppler shift based on ephemeris information for non-terrestrial network (NTN) device and position information of the UE. The method may comprise transmitting a message including compensation information to a network node through the NTN device based on the compensation. The compensation information may indicate at least one of a frequency shift value according to the doppler shift or a doppler shift change rate indicating a change rate of a frequency shift value per unit time. The NTN device may comprise a satellite that moves based on the ephemeris information.
In embodiments, a method performed by a network node may comprise receiving, from a non-terrestrial network (NTN) device through a user equipment (UE), a message including compensation information for doppler shift. The method may comprise identifying at least one of a frequency shift value according to the doppler shift or a doppler shift change rate indicating a change rate of a frequency shift value per unit time, from the compensation information. The compensation information may be associated with ephemeris information for the non-terrestrial network (NTN) device and position information of the UE.
In embodiments, a device of a user equipment (UE) may comprise at least one transceiver and at least one processor coupled to the at least one transceiver. The at least one processor may be configured to perform a compensation for doppler shift based on ephemeris information for non-terrestrial network (NTN) device and position information of the UE. The at least one processor may be configured to transmit a message including compensation information to a network node through the NTN device based on the compensation. The compensation information may indicate at least one of a frequency shift value according to the doppler shift or a doppler shift change rate indicating a change rate of a frequency shift value per unit time. The NTN device may comprise a satellite that moves based on the ephemeris information.
In embodiments, a device of a network node may comprise at least one transceiver and at least one processor coupled to the at least one transceiver. The at least one processor may be configured to receive, from a non-terrestrial network (NTN) device through a user equipment (UE), a message including compensation information for doppler shift. The at least one processor may be configured to identify at least one of a frequency shift value according to the doppler shift or a doppler shift change rate indicating a change rate of a frequency shift value per unit time, from the compensation information. The compensation information may be associated with ephemeris information for the non-terrestrial network (NTN) device and position information of the UE.
Terms used in the present disclosure are used only to describe a specific embodiment and may not be intended to limit the scope of another embodiment. A singular expression may include a plural expression unless it is clearly meant differently in the context. The terms used herein, including a technical or scientific term, may have the same meaning as generally understood by a person having ordinary knowledge in the technical field described in the present disclosure. Terms defined in a general dictionary among the terms used in the present disclosure may be interpreted with the same or similar meaning as a contextual meaning of related technology, and unless clearly defined in the present disclosure, it is not interpreted in an ideal or excessively formal meaning. In some cases, even terms defined in the present disclosure cannot be interpreted to exclude embodiments of the present disclosure.
In various embodiments of the present disclosure described below, a hardware approach is described as an example. However, since the various embodiments of the present disclosure include technology that use both hardware and software, the various embodiments of the present disclosure do not exclude a software-based approach.
A term referring to a signal (e.g., signal, information, message, signaling), a term referring to resource (e.g., symbol, slot, subframe, radio frame, subcarrier, resource element (RE), resource block (RB), bandwidth part (BWP), occasion), a term for operation state (e.g., step, operation, procedure), a term referring to data (e.g., packet, user stream, information, bit, symbol, codeword), a term referring to a channel, a term referring to network entities, a term referring to a component of an apparatus, and the like used in the following description are illustrated for convenience of description. Accordingly, the present disclosure is not limited to terms described below, and another term having an equivalent technical meaning may be used.
In the following description, a physical channel and a signal may be used interchangeably with data or a control signal. For example, a physical downlink shared channel (PDSCH) is a term referring to a physical channel through which data is transmitted, but the PDSCH may also be used to refer to data. In other words, in the present disclosure, the expression ‘transmitting a physical channel’ may be interpreted as equivalent to the expression ‘transmitting data or a signal through a physical channel’.
Hereinafter, in the present disclosure, higher signaling refers to a signal transmission method transmitted from a base station to a terminal using a downlink data channel of a physical layer or from the terminal to the base station using a uplink data channel of the physical layer. Higher signaling may be understood as radio resource control (RRC) signaling or MAC control element (hereinafter, ‘CE’).
In addition, in the present disclosure, in order to determine whether a specific condition is satisfied or fulfilled, an expression of more than or less than may be used, but this is only a description for expressing an example and does not exclude description of more than or equal to or less than or equal to. A condition described as ‘more than or equal to’ may be replaced with ‘more than’, a condition described as ‘less than or equal to’ may be replaced with ‘less than’, and a condition described as ‘more than or equal to and less than’ may be replaced with ‘more than and less than or equal to’. In addition, hereinafter, ‘A’ to ‘B’ means at least one of elements from A (including A) and to B (including B).
Although the present disclosure describes various embodiments using terms used in some communication standards (e.g., 3rd Generation Partnership Project (3GPP), European Telecommunications Standards Institute (ETSI), extensible radio access network (xRAN), and open-radio access network (O-RAN)), it is only an example for explanation. Various embodiments of the present disclosure may be easily modified and be applied to other communication.
Referring to
The terminal 110 is a device used by a user and performs communication with the terminal 110 through a wireless channel. A link from the base station 120 to the terminal 110 is referred to as downlink (DL), and a link from the terminal 120 to the base station 120 is referred to as uplink (UL). In addition, although not illustrated in
The terminal 110 may be referred to as ‘user equipment (UE)’, ‘vehicle’, ‘customer premises equipment (CPE), ‘mobile station’, ‘subscriber station’, ‘remote terminal’, ‘wireless terminal’, ‘electronic device’, ‘user device’ or another term with equivalent technical meaning, in addition to terminal.
The base station 120 is a network infrastructure that provides wireless access to the terminal 110. The terminal 110 has a coverage defined based on a distance at which a signal may be transmitted. The terminal 110 may be referred to as ‘access point (AP)’, ‘eNodeB (eNB)’, ‘5th generation node’, ‘next generation nodeB (gNB)’, ‘transmission/reception point (TRP)’ or another term with equivalent technical meaning, in addition to the base station.
The base station 120 may communicate with a core network entity 130. For example, the core network entity 130 may include an access and management function (AMF). In addition, for example, the core network entity 130 may include a user plane function (UPF).
The terminal 110 may perform beamforming with the base station 120. The terminal 110 and the base station 120 may transmit and receive a radio signal in a relatively low frequency band (e.g., frequency range 1 (FR 1) of NR). In addition, the terminal 110 and the base station 120 may transmit and receive a radio signal in a relatively high frequency band (e.g., FR 2 (or FR 2-1, FR 2-2, FR 2-3), FR 3 of NR), and a mmWave band (e.g., 28 GHz, 30 GHz, 38 GHz, 60 GHz). In order to improve a channel gain, the terminal 110 and the base station 120 may perform beamforming. Herein, the beamforming may include transmission beamforming and reception beamforming. The terminal 110 and the base station 120 may assign directivity to the transmission signal or the reception signal. To this end, the terminal 110 and the base station 120 may select serving beams through a beam search or a beam management procedure. After the serving beams are selected, subsequent communication may be performed through a resource in a QCL relationship with a resource used to transmit or receive signals of the serving beams.
If large-scale characteristics of a channel delivering a symbol on a first antenna port may be inferred from a channel delivering a symbol on a second antenna port, the first antenna port and the second antenna port may be evaluated as being in a QCL relationship. For example, the large-scale characteristics may include at least one of delay spread, doppler spread, doppler shift, average gain, average delay, or spatial receiver parameter.
Both the terminal 110 and the base station 120 may perform beamforming, but embodiments of the present disclosure are not limited thereto. In some embodiments, the terminal 110 may or may not perform beamforming. In addition, the base station 120 may or may not perform beamforming. In other words, only one of the terminal 110 and the base station 120 may perform beamforming, or neither the terminal 110 nor the base station 120 may perform beamforming.
In the present disclosure, a beam refers to a spatial flow of a signal in a wireless channel, and is formed by one or more antennas (or antenna elements), and this formation process may be referred to as beamforming. The beamforming may include at least one of analog beamforming or digital beamforming (e.g., precoding). A reference signal transmitted based on beamforming may include, for example, a demodulation-reference signal (DM-RS), a channel state information-reference signal (CSI-RS), a synchronization signal/physical broadcast channel (SS/PBCH), and a sounding reference signal (SRS). In addition, IE such as CSI-RS resource or SRS-resource may be used as a configuration for each reference signal, and the configuration may include information associated with the beam. The information associated with the beam may mean whether the configuration (e.g., CSI-RS resource) uses the same spatial domain filter or a different spatial domain filter with as another configuration (e.g., another CSI-RS resource in the same CSI-RS resource set) or mean which reference signal is quasi-co-located (QCL), or mean what type (e.g., QCL type A, B, C, D) if it is QCL.
Hereinafter, in order to describe embodiments, the terminal may be referred to as a UE 110 and the base station may be referred to as a gNB 120.
Referring to
The NTN payload 221 may receive wireless protocol data from the UE 110 through the service link. The NTN payload 221 may transparently transmit the wireless protocol data to the NTN gateway 223 through the feeder link. Therefore, the NTN payload 221 and the NTN gateway 223 may be considered as one gNB 120 from perspective of the UE 110. The NTN payload 221 and the NTN gateway 223 may communicate with the UE 110 through a Uu interface, which is a general wireless protocol. In other words, the NTN payload 221 and the NTN gateway 223 may perform wireless protocol communication with the UE 110, such as one gNB 120. The NTN gateway 223 may communicate with a core network entity 235 (AMF or UPF) through an NG interface.
According to an embodiment, the NTN payload 221 and the NTN gateway 223 may use a wireless protocol stack in a control plane of
In
Referring to
In NTN access, a main function of the RRC layer may include at least a part of the following functions.
In NTN access, a main function of the PDCP layer may include at least a part of the following functions.
In NTN access, a main function of the RLC layer may include at least a part of the following functions.
In NTN access, the MAC layer may be connected to a plurality of RLC layer devices configured on a terminal, and a main function of the MAC may include at least a part of the following functions.
In NTN access, the physical layer may include channel coding and modulating higher layer data, making into an OFDM symbol, and transmitting to a wireless channel, or demodulating the OFDM symbol received through a wireless channel, channel decoding, and transmitting to a higher layer.
Referring to
In NTN access, the SDAP layer may provide a QoS flow of 5GC. A single protocol entity of the SDAP may be configured for each individual PDU session, and a function of the SDAP layer may include at least a part of the following functions.
Referring to
In the time-frequency domain, a basic unit of resources is a resource element (hereinafter, ‘RE’) 412, which may be represented as an OFDM symbol index and a subcarrier index. A resource block may include a plurality of resource elements. In an LTE system, the resource block (RB) (or physical resource block (hereinafter, ‘PRB’) is defined as Nsymb consecutive OFDM symbols in the time domain and NSCRB consecutive subcarriers in the frequency domain. In an NR system, the RB 408 may be defined as NSCRB consecutive subcarriers 410 in the frequency domain. One RB 408 includes NSCRB REs 412 on the frequency axis. In general, a minimum transmission unit of data is RB, and a number of subcarriers is NSCRB=12. The frequency domain may include common resource blocks (CRBs). The PRB may be defined in a bandwidth part (BWP) in the frequency domain. The CRB and PRB numbers may be determined according to subcarrier spacing. A data rate may increase in proportion to a number of RBs scheduled for the terminal.
In the NR system, a downlink transmission bandwidth and an uplink transmission bandwidth may be different, in case of a frequency division duplex (FDD) system that operates by dividing downlink and uplink by frequency. A channel bandwidth indicates a radio frequency (RF) bandwidth corresponding to a system transmission bandwidth. Table 1 shows a part of a correspondence between the system transmission bandwidth, subcarrier spacing (SCS) and channel bandwidth defined in the NR system in a frequency band (e.g., a frequency range (FR) 1 (410 MHz to 7,125 MHz)) lower than x GHz. And Table 2 shows a part of a correspondence relationships between a transmission bandwidth, subcarrier spacing, and channel bandwidth defined in the NR system in a frequency band (e.g., FR2 (24,550 MHz-52,600 MHz) or FR2-2 (52,600 MHz to 71,000 MHz)) higher than yGHz. For example, in an NR system having a 100 MHz channel bandwidth at 30 kHz subcarrier spacings, a transmission bandwidth is configured with 273 of RBs. In Table 1 and Table 2, N/A may be a bandwidth-subcarrier combination that is not supported by the NR system.
Referring to
For operation of the NTN 500, operation and maintenance (O&M) 510 may provide one or more parameters associated with the NTN 500 to the gNB 120. The O&M 510 may control an NTN control function 520 and a non-NTN infrastructure gNB function 530.
The NTN control function 520 may control a spacecraft (or airline) vehicle as well as a radio resource of the NTN infrastructure 525 (the NTN payload 221 and the NTN gateway 223). In addition, the NTN control function 520 may provide control data (e.g., ephemeris information) to the non-NTN infrastructure gNB function 530.
The gNB 120 may be subdivided into the non-NTN infrastructure gNB function 530 and an NTN service link provisioning system 535. The NTN infrastructure 525 may be subdivided into the NTN control function 520 and the NTN service link provisioning system 535. The NTN service link provisioning system 535 may configured with one or more NTN payloads (e.g., the NTN payload 221) and an NTN gateway (e.g., the NTN gateway 223). The NTN service link provisioning system 535 may map an NR-Uu radio protocol to a radio resource (e.g., beam, channel, Tx power) of the NTN infrastructure 525.
The operation and maintenance (O&M) 510 may provide at least the following NTN-related parameters to the gNB 120 for operation.
Referring to
The NTN payload 221 is flying in a certain direction. As the NTN payload 221 moves in the certain direction, the NTN payload 221 may become close to the UE 110. The NTN payload 221 may be connected to another terminal, which is the UE, through another service link. However, as the NTN payload 221 moves in the certain direction, the NTN payload 221 may move away from the UE. Hereinafter, for convenience of explanation, as the NTN payload 221 moves, a terminal that becomes closer may be referred to as a downstream UE, and a terminal that moves away may be referred to as an upstream UE.
Referring to
Referring to
As described in
According to the embodiments of the present disclosure, in order to solve the above-described problem, the UE 110 (hereinafter, as upstream UE) and af network (e.g., the NTN payload 221 and the NTN gateway 223) may compensate for the Doppler shift and share the compensated Doppler shift information. According to an embodiment, the UE 110 may transmit information on pre-compensated Doppler shift to a network end, which is the NTN payload 221 and the NTN gateway 223. In addition, according to an embodiment, the UE 110 may receive information on the Doppler shift compensated or used for compensation on a network side from the NTN payload 221. Hereinafter, detailed signaling is described with reference to
In case of a serving cell, a network may broadcast ephemeris information and common TA parameters. The UE 110 is required to have a valid GNSS position, satellite ephemeris, and the common TA before connecting to an NTN cell. To achieve synchronization, before and during connection to the NTN cell, the UE may calculate service link RTT based on the GNSS position and satellite ephemeris, and automatically compensate for the TTA in advance.
The UE 110 may calculate frequency Doppler shift in consideration of a position of the UE 110 and the satellite ephemeris. In case that the UE 110 does not have the valid global navigation satellite system (GNSS) position and/or the valid satellite ephemeris, the UE 110 may not communicate with the network until having both the valid GNSS location and the valid satellite ephemeris. In a connected mode, the UE 110 should be able to continuously update timing advance (TA) and frequency pre-compensation. According to an embodiment, the UE 110 may be configured to report the TA during a random access procedure or in the connection mode. During the random access procedure or in the connection mode, the UE 110 may be configured to report frequency pre-compensation information.
Referring to
F=Fo*V*cos(θ)/c [Equation 1]
Here, ‘Fo’ is the nominal carrier frequency, ‘v’ is a UE speed, and ‘θ’ is an angle between a moving direction and a communication direction. The communication direction refers to a direction of the NTN payload 221 in the UE 110. ‘c’ indicates a speed of light.
The UE 110 may generate compensation information based on the Doppler shift. Compensation performed in the UE 110 may correspond to pre-compensation. The compensation information may include various information on the pre-compensation performed in the UE 110. According to an embodiment, the compensation information may include information on a Doppler shift value. The Doppler shift value refers to a value (e.g., fd of
In operation 903, the UE 110 may transmit compensation information to the NTN payload 221. In operation 905, the NTN payload 221 may transmit compensation information to the NTN gateway 223. In
In some embodiments, the UE 110 may transmit the compensation information through a random access procedure. The UE 110 may initiate the random access procedure for the Doppler shift. In perspective of the UE 110, the random access procedure may include a random access preamble transmission and a random access response reception. The UE 110 may transmit the compensation information to the network through the random access preamble transmission.
According to an embodiment, a sequence for generating a random access preamble may indicate the Doppler shift value. In a set of preambles configured through a radio resource control (RRC) signaling, a specific preamble sequence defined for use in the Doppler shift may be identified. A value of the preamble sequence may depend on the Doppler shift value. For example, in case that an index for the preamble sequence is 1, the Doppler shift value may be about −707 hertz (Hz). In addition, for example, in case that the index for the preamble sequence is 2, the Doppler shift value may be about −1414 Hz.
According to an embodiment, a time-frequency resource in which the random access preamble is transmitted, that is a physical random access channel (PRACH) occasion, may indicate the Doppler shift value. Each of a plurality of PRACH occasions may be associated with a specific Doppler shift value. A relationship between the PRACH occasions and predefined Doppler shift values may be established through the RRC signaling. An index of the PRACH occasion may be dependent on the Doppler shift value. For example, in case that the index of the PRACH occasion is 3, the Doppler shift value may be about 2.25 hertz (Hz). In addition, for example, in case that the index of PRACH occasion is 4, the Doppler shift value may be about 22.5 Hz.
According to an embodiment, a combination of the PRACH occasion and a sequence in which the random access preamble is transmitted may indicate the Doppler shift value. For example, the PRACH occasion may indicate a group of Doppler shift values, and the sequence may indicate a specific Doppler shift value within the group. In addition, for example, the sequence may indicate a group of Doppler shift values, and the PRACH occasion may indicate a specific Doppler shift value within the group.
In some other embodiments, the UE 110 may transmit compensation information through a control signaling. According to an embodiment, the UE 110 may transmit compensation information through a separately defined physical layer signaling. For example, at least part of the compensation information may be included as a component of channel state information (CSI). The UE 110 may transmit the compensation information to a base station end (e.g., the gNB 120, the network (the NTN payload 221 and the NTN gateway 223)) through the physical uplink control channel (PUCCH).
According to an embodiment, the UE 110 may transmit the compensation information through a separately defined MAC control element (CE). The MAC CE including the compensation information may be identified by a MAC sub header having LCID. The MAC CE including the compensation information may have a fixed size and may be composed of one or more octets. In order to transmit the MAC CE, two RRC parameters may be additionally defined. According to an embodiment, a frequency threshold may be configured for the UE 110. In case that a difference between a previously reported frequency compensation value (i.e., the Doppler shift value) and a current frequency compensation value exceeds the frequency threshold, a transmission of the MAC CE may be triggered. In addition, according to an embodiment, a compensation scheduling request (SR) may be configured for the UE 110. If there is no uplink resource (e.g., a UL-shared channel (SCH) resource) for reporting, the UE 110 may trigger the scheduling request in case that the compensation SR is configured. According to an additional embodiment, the MAC CE may be used together for timing advance (TA) reporting. A current standard separately defines a timing advance report (TAR) MAC CE, but a TA value to be included in the TAR MAC CE may be included in the MAC CE and transmitted together.
In order to report the compensation information of the UE 110, the base station end (e.g., the gNB 120, the network (the NTN payload 221, and the NTN gateway 223)) may transmit configuration information for reporting to the UE 110 through the RRC signaling. According to an embodiment, an RRC configuration message for reporting the compensation information may be defined. The RRC configuration message may include time domain action information for the compensation information of the Doppler shift, index information for the Doppler shift value, and default parameters to be applied when calculating Doppler. Time domain action information may indicate whether the report is periodic, semi-persistent, or aperiodic. In case that the report is periodic or semi-persistent, the time domain action information may further include information on a period. The index information may indicate a Doppler shift value. For example, various Doppler shift values are divided into specified ranges, and each range and index may be related. Alternatively, for another example, the Doppler shift value is represented in a form of a ratio (e.g., 1, ½, ¼, ⅛, 1/16) for a single subcarrier, and a value of each ratio may be associated with an index. The index information may include information for indicating the association. Basic parameters to be applied may include a parameter associated with movement of a satellite (i.e., the NTN payload 221) or a parameter associated with a basic channel model for a service link between the UE 110 and the NTN payload 221.
Referring to
The gNB 120 may generate frequency offset information based on the Doppler shift. According to an embodiment, compensation information may include information on a Doppler shift value. According to an embodiment, the compensation information may include information on a Doppler rate. According to an embodiment, the compensation information may include information on a carrier frequency on which Doppler shift is performed.
The gNB 120 may generate frequency offset information for each designated unit. According to an embodiment, the gNB 120 may generate frequency offset information for each cell. This is because when referring to Equation 1, the carrier frequency is defined for each cell. The gNB 120 may associate frequency offset information with a cell index (e.g., Ci, ‘i’ is an index number). In addition, according to an embodiment, the gNB 120 may generate frequency offset information for each BWP. In case of performing communication, only one BWP may be activated in UL or DL. Since each BWP has a center frequency, the influence of the Doppler shift may be dependent on the BWP when referring to Equation 1. The gNB 120 may associate the frequency offset information with BWP ID. For example, the BWP ID of initial BWP may be ‘0’. In addition, according to an embodiment, the gNB 120 may generate frequency offset information for each beam. A wireless communication module of the gNB 120 may be located in the NTN payload 221. A link between the NTN payload 221 and the UE 110, that is a length and a direction of a service link, depends on a serving beam (e.g., a synchronization signal block (SSB) resource indicator (SSBRI) and a CSI-RS indicator (CRI)). Referring to Equation 1, an angle (é) between a moving direction and a link may depend on directivity of the serving beam. The gNB 120 may associate frequency offset information with beam information.
In operation 1003, the gNB 120 may transmit frequency offset information to the UE 110. The gNB 120 may transmit frequency offset information to the UE 110 in various ways. According to an embodiment, the gNB 120 may transmit frequency offset information to the UE 110 through an RRC message. In addition, according to an embodiment, the gNB 120 may transmit the frequency offset information to the UE 110 through MAC CE. In addition, according to an embodiment, the gNB 120 may transmit the frequency offset information to the UE 110 through downlink control information (DCI). In addition, according to an embodiment, the frequency offset information may be indicated based on two control signaling rather than a single signaling. For example, a range of the frequency offset information may be configured through the RRC message, and the MAC CE or the DCI may be used to indicate code points within the range.
Although an operation of the gNB 120 is described in
Referring to
The transceiver 1101 performs functions for transmitting and receiving a signal through a wireless channel. For example, the transceiver 1101 up-converts a baseband signal into an RF band signal and transmits it through an antenna, and down-converts the RF band signal received through the antenna into a baseband signal. For example, the transceiver 1101 may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a DAC, an ADC, and the like.
The transceiver 1101 may include a plurality of transmission/reception paths. Furthermore, the transceiver 1101 may include an antenna unit. The transceiver 1101 may include at least one antenna array composed of a plurality of antenna elements. In terms of hardware, the transceiver 1101 may be configured with a digital circuit and an analog circuit (e.g., a radio frequency integrated circuit (RFIC)). Herein, the digital circuit and the analog circuit may be implemented as one package. In addition, the transceiver 1101 may include a plurality of RF chains. The transceiver 1101 may perform beamforming. In order to give directionality according to the configuration of the processor 1103 to a signal intended to transmit and receive, the transceiver 1101 may apply a beamforming weight to the signal. According to an embodiment, the transceiver 1101 may include a radio frequency (RF) block (or RF unit).
The transceiver 1101 may transmit and receive a signal on a radio access network. For example, the transceiver 1101 may transmit a downlink signal. The downlink signal may include a synchronization signal (SS), a reference signal (RS) (e.g., a cell-specific reference signal (CRS), demodulation (DM)-RS), system information (e.g. MIB, SIB, remaining system information (RMSI), other system information (OSI)), a configuration message, control information, or downlink data. In addition, for example, the transceiver 1101 may receive an uplink signal. The uplink signal may include a random access-related signal (e.g., random access preamble (RAP) (or message 1 (Msg1)), message 3 (Msg3)), a reference signal (e.g., sounding reference signal (SRS), DM-RS), or power headroom report (PHR). In
The processor 1103 controls overall operations of the NTN payload 221. The processor 1103 may be referred to as a control unit. For example, the processor 1103 transmits and receives a signal through the transceiver 1101. In addition, the processor 1103 writes and reads data into the memory 1105. In addition, the processor 1103 may perform functions of protocol stack required by communication standard. In
The memory 1105 stores data such as a basic program, an application program, and configuration information for the operation of the NTN payload 221. The memory 1105 may be referred to as a storage unit. The memory 1105 may be configured as a volatile memory, a nonvolatile memory, or a combination of the volatile memory and the nonvolatile memory. In addition, the memory 1105 provides stored data according to a request of the processor 1103. According to an embodiment, the memory 1105 may include a memory for a condition, an instruction, or a configuration value associated with an SRS transmission scheme.
Referring to
The transceiver 1151 may perform functions for transmitting and receiving a signal in a wired communication environment. The transceiver 1151 may include a wired interface to control a direct connection between devices through a transmission medium (e.g., copper wire, optical fiber). For example, the transceiver 1151 may transmit an electrical signal to another device through copper wire or perform conversion between an electrical signal and an optical signal. The NTN gateway 223 may communicate with the NTN payload 221 through the transceiver 1151. The NTN gateway 223 may be connected to a core network or a CU in a distributed deployment through the transceiver 1151.
The transceiver 1151 may perform functions for transmitting and receiving a signal in a wireless communication environment. For example, the transceiver 1151 may perform a conversion function between a baseband signal and a bit string according to a physical layer standard of a system. For example, when transmitting data, the transceiver 1151 generates complex-valued symbols by encoding and modulating a transmission bit string. In addition, when receiving data, the transceiver 1151 restores a reception bit string by demodulating and decoding the baseband signal. In addition, the transceiver 1151 may include a plurality of transmission/reception paths. In addition, according to an embodiment, the transceiver 1151 may be connected to a core network or other nodes (e.g., integrated access backhaul (IAB)).
As described above, the transceiver 1151 transmits and receives a signal. Accordingly, all or part of the transceiver 1151 may be referred to as a ‘communication unit’, ‘transmission unit’, ‘reception unit’, or ‘transmission unit’. In addition, in the following description, a transmission and reception performed through a wireless channel includes meaning that processing as described above is performed by the transceiver 1151.
The processor 1153 controls overall operations of the NTN gateway 223. The processor 1153 may be referred to as a control unit. For example, the processor 1153 transmits and receives a signal through the transceiver 1151 (or through the backhaul transceiver 1157). In addition, the processor 1153 writes and reads data into the memory 1155. In addition, the processor 1153 may perform functions of protocol stack required by communication standard. In
The memory 1155 stores data such as a basic program, an application program, and configuration information for the operation of the NTN gateway 223. The memory 1155 may be referred to as a storage unit. The memory 1155 may be configured as a volatile memory, a nonvolatile memory, or a combination of the volatile memory and the nonvolatile memory. In addition, the memory 1155 provides stored data according to a request of the processor 1153.
The NTN gateway 223 may further include a backhaul transceiver 1157 for connecting with a core network or another base station. The backhaul transceiver 1157 provides an interface for performing communication with other nodes in a network. In other words, the backhaul transceiver 1157 converts a bit string transmitted from abase station to another node, for example, another access node, another base station, higher node, core network, and the like, into a physical signal, and converts a physical signal received from another node into a bit string.
Referring to
The processor 1201 controls overall operations of the UE 110. For example, the processor 1201 writes and reads data into the memory 1203. For example, the processor 1201 transmits and receives a signal through the transceiver 1205. Although one processor is illustrated in
The memory 1203 may store data such as a basic program, an application program, and configuration information for an operation of the UE 110. The memory 1203 may store various data used by at least one component (e.g., the transceiver 1205 and the processor 1201). The data may include, for example, input data or output data for software and related commands. The memory 1203 may be configured as a volatile memory, a nonvolatile memory, or a combination of the volatile memory and the nonvolatile memory. In addition, the memory 1203 may provide stored data according to a request of the processor 1201.
The transceiver 1205 performs functions for transmitting and receiving a signal through a wireless channel. For example, the transceiver 1205 performs a conversion function between a baseband signal and a bit string according to a physical layer standard of a system. For example, when transmitting data, the transceiver 1205 generates complex-valued symbols by encoding and modulating a transmission bit string. In addition, when receiving data, the transceiver 1205 restores a reception bit string by demodulating and decoding a baseband signal. the transceiver 1101 up-converts a baseband signal into an RF band signal and transmits it through an antenna, and down-converts the RF band signal received through the antenna into a baseband signal.
To this end, the transceiver 1205 may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a digital to analog converter (DAC), an analog to digital converter (ADC), and the like. In addition, the transceiver 1205 may include a plurality of transmission/reception paths. Furthermore, the transceiver 1205 may include at least one antenna array composed of a plurality of antenna elements. In terms of hardware, the transceiver 1205 may be composed of a digital unit and an analog unit, and the analog unit may be composed of a plurality of sub-units according to operating power, operating frequency, and the like.
As described above, the transceiver 1205 transmits and receives a signal. Accordingly, the transceiver 1205 may be referred to as a ‘transmission unit’, a ‘reception unit’, or a ‘transmission/reception unit’. In addition, in the following description, transmission and reception performed through a wireless channel, a backhaul network, optical cable, Ethernet, and other wired paths includes meaning that processing as described above is performed by the transceiver 1205. According to an embodiment, the transceiver 1205 may provide an interface for performing communication with other nodes in a network. In other words, the transceiver 1205 converts a bit string transmitted from the UE 110 to another node, for example, another access node, another base station, higher node, core network, and the like, into a physical signal, and converts a physical signal received from another node into a bit string.
In embodiments, a method performed by a user equipment (UE) may comprise performing a compensation for doppler shift based on ephemeris information for non-terrestrial network (NTN) device and position information of the UE. The method may comprise transmitting a message including compensation information to a network node through the NTN device based on the compensation. The compensation information may indicate at least one of a frequency shift value according to the doppler shift or a doppler shift change rate indicating a change rate of a frequency shift value per unit time. The NTN device may comprise a satellite that moves based on the ephemeris information.
According to an embodiment, the compensation information may be transmitted through a medium access control (MAC) control element (CE). A transmission of the MAC CE may be triggered in case that a difference between a previously reported compensation value and a current compensation value is greater than a threshold. The threshold may be configured through a radio resource control (RRC) signaling.
According to an embodiment, the compensation information may be transmitted by a transmission of a random access preamble of a random access procedure. At least one of a sequence of the random access preamble or a physical random access channel (PRACH) occasion in which the random access preamble is transmitted may indicate the frequency shift value.
According to an embodiment, the method may comprise receiving, from the network node through the NTN device, information on a frequency offset. The frequency offset may be associated with a compensation in a network for the doppler shift. The frequency offset may be associated with at least one of a cell, bandwidth part (BWP) identifier (ID), or a beam identifier.
According to an embodiment, the method may comprise receiving, from the network node through the NTN device, a radio resource control (RRC) message for indicating a range for the frequency offset. The information may comprise a medium access control (MAC) control element (CE) or downlink control information (DCI) for indicating the frequency offset within the range.
In embodiments, a method performed by a network node may comprise receiving, from a non-terrestrial network (NTN) device through a user equipment (UE), a message including compensation information for doppler shift. The method may comprise identifying at least one of a frequency shift value according to the doppler shift or a doppler shift change rate indicating a change rate of a frequency shift value per unit time, from the compensation information. The compensation information may be associated with ephemeris information for the non-terrestrial network (NTN) device and position information of the UE.
According to an embodiment, the compensation information may be received through a medium access control (MAC) control element (CE). A transmission of the MAC CE may be triggered in case that a difference between a previously reported compensation value and a current compensation value is greater than a threshold. The threshold may be configured through a radio resource control (RRC) signaling.
According to an embodiment, the compensation information may be received by a transmission of a random access preamble of a random access procedure. At least one of a sequence of the random access preamble or a physical random access channel (PRACH) occasion in which the random access preamble is transmitted may indicate the frequency shift value.
According to an embodiment, the method may comprise transmitting, to the UE through the NTN device, information on a frequency offset. The frequency offset may be associated with a compensation in a network for the doppler shift. The frequency offset may be associated with at least one of a cell, bandwidth part (BWP) identifier (ID), or a beam identifier.
According to an embodiment, the method may comprise transmitting, to the UE through the NTN device, a radio resource control (RRC) message for indicating a range for the frequency offset. The information may comprise a medium access control (MAC) control element (CE) or downlink control information (DCI) for indicating the frequency offset within the range.
In embodiments, a device of a user equipment (UE) may comprise at least one transceiver and at least one processor coupled to the at least one transceiver. The at least one processor may be configured to perform a compensation for doppler shift based on ephemeris information for non-terrestrial network (NTN) device and position information of the UE. The at least one processor may be configured to transmit a message including compensation information to a network node through the NTN device based on the compensation. The compensation information may indicate at least one of a frequency shift value according to the doppler shift or a doppler shift change rate indicating a change rate of a frequency shift value per unit time. The NTN device may comprise a satellite that moves based on the ephemeris information.
According to an embodiment, the compensation information may be transmitted through a medium access control (MAC) control element (CE). A transmission of the MAC CE may be triggered in case that a difference between a previously reported compensation value and a current compensation value is greater than a threshold. The threshold may be configured through a radio resource control (RRC) signaling.
According to an embodiment, the compensation information may be transmitted by a transmission of a random access preamble of a random access procedure. At least one of a sequence of the random access preamble or a physical random access channel (PRACH) occasion in which the random access preamble is transmitted may indicate the frequency shift value.
According to an embodiment, the at least one processor may be further configured to receive, from the network node through the NTN device, information on a frequency offset. The frequency offset may be associated with a compensation in a network for the doppler shift. The frequency offset may be associated with at least one of a cell, bandwidth part (BWP) identifier (ID), or a beam identifier.
According to an embodiment, the at least one processor may be further configured to receive, from the network node through the NTN device, a radio resource control (RRC) message for indicating a range for the frequency offset. The information may comprise a medium access control (MAC) control element (CE) or downlink control information (DCI) for indicating the frequency offset within the range.
In embodiments, a device of a network node may comprise at least one transceiver and at least one processor coupled to the at least one transceiver. The at least one processor may be configured to receive, from a non-terrestrial network (NTN) device through a user equipment (UE), a message including compensation information for doppler shift. The at least one processor may be configured to identify at least one of a frequency shift value according to the doppler shift or a doppler shift change rate indicating a change rate of a frequency shift value per unit time, from the compensation information. The compensation information may be associated with ephemeris information for the non-terrestrial network (NTN) device and position information of the UE.
According to an embodiment, the compensation information may be received through a medium access control (MAC) control element (CE). A transmission of the MAC CE may be triggered in case that a difference between a previously reported compensation value and a current compensation value is greater than a threshold. The threshold may be configured through a radio resource control (RRC) signaling.
According to an embodiment, the compensation information may be received by a transmission of a random access preamble of a random access procedure. At least one of a sequence of the random access preamble or a physical random access channel (PRACH) occasion in which the random access preamble is transmitted may indicate the frequency shift value.
According to an embodiment, the at least one processor may be configured to transmit, to the UE through the NTN device, information on a frequency offset. The frequency offset may be associated with a compensation in a network for the doppler shift. The frequency offset may be associated with at least one of a cell, bandwidth part (BWP) identifier (ID), or a beam identifier.
According to an embodiment, the at least one processor may be configured to transmit, to the UE through the NTN device, a radio resource control (RRC) message for indicating a range for the frequency offset. The information may comprise a medium access control (MAC) control element (CE) or downlink control information (DCI) for indicating the frequency offset within the range.
According to embodiments of the present disclosure, effective frequency compensation may be provided by transmitting information on Doppler shift in a non-terrestrial network (NTN). More specifically, as the UE performs pre-compensation and provides compensation information to the network, a network side may identify compensation for the Doppler shift performed at the UE. If necessary, a network node (e.g., the gNB 120) may supplement the pre-compensation through additional compensation and instruct the UE with a changed frequency offset.
Effects obtained in the present disclosure are not limited to those described above effects, and other effects not mentioned herein will be clearly understood by those having ordinary knowledge in the art to which the present disclosure belongs, from the following description.
Methods according to embodiments described in claims or specifications of the present disclosure may be implemented as a form of hardware, software, or a combination of hardware and software.
In case of implementing as software, a computer-readable storage medium for storing one or more programs (software module) may be provided. One or more programs stored in the computer-readable storage medium are configured for execution by one or more processors in an electronic device. One or more programs include instructions that allow the electronic device to execute methods according to embodiments described in claims or specifications of the present disclosure.
Such a program (software module, software) may be stored in a random access memory, a non-volatile memory including a flash memory, a read only memory (ROM), an electrically erasable programmable read only memory (EEPROM), a magnetic disc storage device, a compact disc-ROM (CD-ROM), digital versatile discs (DVDs), another type of optical storage device, or a magnetic cassette. Alternatively, it may be stored in a memory composed of a combination of some or all of them. In addition, a plurality of each configuration memory may be included.
Additionally, a program may be stored in an attachable storage device that may be accessed through a communication network such as the Internet, Intranet, local area network (LAN), wide area network (WAN), or storage area network (SAN), or a combination of them. Such a storage device may be connected to a device performing an embodiment of the present disclosure through an external port. In addition, a separate storage device on the communication network may also access a device that performs embodiment of the present disclosure.
In specific embodiments of the present disclosure described above, an element included in the disclosure are represented in singular or plural numbers according to a specific embodiment presented. However, singular or plural expressions are selected to suit the presented situation for convenience of explanation, the present disclosure is not limited to singular or plural components, and even a component represented in the plural may be composed of a singular number, or a component represented in the singular may be composed of a plural number.
Meanwhile, in the detailed description of the present disclosure, specific embodiments have been described, but of course, various modifications are possible without departing from the scope of the present disclosure.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2022-0140764 | Oct 2022 | KR | national |
