WO2022038549A1

WO2022038549A1 - User equipment and method of communication

Info

Publication number: WO2022038549A1
Application number: PCT/IB2021/057621
Authority: WO
Inventors: Hao Lin
Original assignee: Orope France Sarl
Priority date: 2020-08-19
Filing date: 2021-08-19
Publication date: 2022-02-24

Abstract

A user equipment and a method of communication of the same are provided. The method includes providing, to a UE, a first information; the first information is used to determine a slot location.

Description

USER EQUIPMENT AND METHOD OF COMMUNICATION

TECHNICAL FIELD

The present disclosure relates to the field of communication systems, and more particularly, to an apparatus (such as a user equipment (UE) and/or a base station) and a method for transmission adjustment in a non-terrestrial network (NTN), which can provide a good communication performance and high reliability.

BACKGROUND

Non-terrestrial networks (NTNs) refer to networks, or segments of networks, using a spacebome vehicle or an airborne vehicle for transmission. Spaceborne vehicles include satellites including low earth orbiting (LEO) satellites, medium earth orbiting (MEO) satellites, geostationary earth orbiting (GEO) satellites, and highly elliptical orbiting (HEO) satellites. Airborne vehicles include high altitude platforms (HAPs) encompassing unmanned aircraft systems (UAS) including lighter than air (LTA) unmanned aerial systems (UAS) and heavier than air (HTA) UAS, all operating in altitudes typically between 8 and 50 km, quasi-stationary.

Communication via a satellite is an interesting means thanks to its well-known coverage, which can bring the coverage to locations that normally cellular operators are not willing to deploy either due to non-stable crowd potential client, e.g. extreme rural, or due to high deployment cost, e.g. middle of ocean or mountain peak. Nowadays, the satellite communication is a separate technology to a 3rd generation partnership project (3 GPP) cellular technology. Coming to 5G era, these two technologies can merge together, i.e. we can imagine to have a 5G terminal that can access to a cellular network and a satellite network. The NTN can be good candidate technology for this purpose. It is to be designed based on 3GPP new radio (NR) with necessary enhancement.

In NTN, due to very high satellite altitude, a round trip time (RTT) between a sender (satellite/user equipment (UE)) and a receiver (UE/satellite) is extremely long. In a release. 15 NR, the RTT is usually short and the slot format indication (SFI) received by a UE from a gNB can be applied immediately from the slot where the UE detects the SFI indication. However, in an NTN system, the legacy SFI applicability needs to be adapted to be suitable for the long RTT situation.

Therefore, there is a need for an apparatus (such as a user equipment (UE) and/or a base station) and a method for SFI applicability adjustment in a non-terrestrial network (NTN), which can solve issues in the prior art, provide a good communication performance and high reliability.

SUMMARY

An object of the present disclosure is to propose a user equipment (UE) and a method of communication, which can solve issues in the prior art and provide a method determining an information based on the other information.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the embodiments of the present disclosure or related art, the following figures will be described in the embodiments are briefly introduced. It is obvious that the drawings are merely some embodiments of the present disclosure, a person having ordinary skill in this field can obtain other figures according to these figures without paying the premise.

FIG. 1 is a block diagram of one or more user equipments (UE) and a base station (e.g., gNB) for transmission adjustment in a communication network system (e.g., non-terrestrial network (NTN)) according to an embodiment of the present disclosure.

FIG. 2 is a flowchart illustrating a method of starting slot of SFI indication determination of a user equipment in a non-terrestrial network (NTN) according to an embodiment of the present disclosure.

FIG. 3 is a flowchart illustrating a method of starting slot of SFI indication determination of a user equipment in a non-terrestrial network (NTN) according to an embodiment of the present disclosure.

DETAIEED DESCRIPTION

In some embodiments, a UE receives a PDCCH from a gNB in a first slot, wherein the PDCCH comprises a DCI format. In some embodiments, the DCI format comprises an indication field, wherein the indication field is used to indicate slot format for a set of slots. In some embodiments, the set of slots are consecutive slots in time domain. In some embodiments, a starting slot of the set of slots comprises the first slot. In some embodiments, the starting slot of the set of slots comprises the first slot plus an offset. In some embodiments, the determination of the starting slot of the set of slots is relevant to a downlink bandwidth part (BWP) or an uplink BWP. In some embodiments, the starting slot of the set of slots comprises the first slot plus the offset for the uplink BWP. In some embodiments, the starting slot of the set of slots comprises the first slot for the downlink BWP. In some embodiments, the starting slot of the set of slots comprises the first slot plus the offset for the uplink BWP for a paired spectrum operation. In some embodiments, the starting slot of the set of slots comprises the first slot plus the offset for the downlink BWP for an unpaired spectrum operation. In some embodiments, the offset comprises an amount of slots, wherein the slot duration is determined based on at least one of the followings: a reference subcarrier spacing, or a subcarrier spacing of an active downlink BWP, or a subcarrier spacing of an active uplink BWP, or a subcarrier spacing of an initial downlink BWP, or a subcarrier spacing of an initial uplink BWP. In some embodiments, the indication field comprises slot format indicator (SFI)-index field. In some embodiments, the DCI format comprises DCI format 2_0. In some embodiments, the gNB indicates a time duration to the UE. In some embodiments, the time duration is indicated in at least one of the followings: system information, or RRC signaling, or MAC-CE, or DCI. In some embodiments, the time duration comprises a unit of at least one of the followings: slot, symbol, or millisecond. In some embodiments, the offset is in unit of at least one of the followings: slot, symbol, millisecond. In some embodiments, the offset is derived by a UE from the time duration. In some embodiments, a timing advance of the UE is derived from the time duration. In some embodiments, the timing advance is applied for an uplink transmission for the UE. In some embodiments, the uplink transmission comprises at least one of the followings: a PRACH transmission, or a PUSCH transmission scheduled by a RAR UL grant, or a PUCCH transmission, or a SRS transmission. In some embodiments, the PUCCH transmission includes a PUCCH transmission scheduled by DCI or scheduled by successRAR according to TS38.213 section 8.2A with CRS scrambled with MsgB-RNTI.

Example 1

As shown in Fig. 1, where a UE detects a DCI format 2_0 in a first slot. The DCI format 2_0 includes a SFI-index field value to indicate to the UE a slot format for each slot in a number of slots for each DL BWP or each UL BWP starting from an earliest slot after an offset from the first slot where the UE detects the DCI format 2_0. In our example we assume that the offset is 5 slots. Optionally, the offset is in a unit of slot or reference slot. When the offset is in a unit of slot, the slot duration is calculated by the subcarrier spacing of the active DL BWP or the active UL BWP. When the offset is in a unit of reference slot, the offset is calculated by a reference subcarrier space and then translate to the number of slots for the active DL BWP or the active UL BWP, e.g. offset is 5 reference slots, with reference subcarrier spacing is 15KHz. For the active DL BWP with 30KHz subcarrier spacing, the offset value is translated to 5 reference slot*30KHz/15KHz=10 slots in active DL BWP. For the active UL BWP with 60KHz subcarrier spacing, the offset value is translated to 5 reference slot*60KHz/15KHz=20 slots in active UL

BWP.

Optionally, as shown in Fig. 1, where a UE detects a DCI format 2_0 in a first slot. The DCI format 2_0 includes a SFI-index field value to indicate to the UE a slot format for each slot in a number of slots for each DL BWP and UL BWP. The slot format for a number of slots for UL BWP is applied from an earliest slot after a first offset from the first slot where the UE detects the DCI format 2_0, However, the slot format for a number of slots for DL BWP is applied from an earliest slot after a second offset the first slot where the UE detects the DCI format 2_0. Optionally, the first offset is in a unit of a first reference slot, the first offset is calculated by a first reference subcarrier space and then translate to the number of slots for the active UL BWP and the second offset is in a unit of a second reference slot, the second offset is calculated by a second reference subcarrier space and then translate to the number of slots for the active DL BWP.

Example 2

For a paired spectrum operation, e.g. FDD (frequency division duplexing) spectrum, where a UE detects a DCI format 2_0 in a first slot. The DCI format 2_0 includes a SFI-index field value to indicate to the UE a slot format for each slot in a number of slots for UL BWP and a SFI-index field value to indicate to the UE a slot format for each slot in a number of slots for DL BWP, respectively. The slot format for a number of slots for UL BWP is applied from an earliest slot after an offset from the first slot where the UE detects the DCI format 2_0, However, the slot format for a number of slots for DL BWP is applied from the first slot where the UE detects the DCI format 2_0, as shown in Fig. 2.

Example 3

In relation with examples 1 and 2, where the offset or the first offset or the second offset is derived by a UE from a signaled duration from a gNB. The signaled duration is in unit of milliseconds. Optionally, the UE derives the offset value or the first offset value or the second offset value based on the signaled duration and a reference slot duration, where the reference slot duration is determined by a reference subcarrier spacing, e.g. a reference subcarrier spacing of 15*2^AU KHZ corresponds to a reference slot duration of 1*2^A'^U milliseconds, where u=0,l,2,3...Optionally, the UE derives the offset value or the first offset value or the second offset value by taking a smallest integer number which is larger than or equal to X, where X is equal to the signaled duration divided by a reference slot duration. Optionally, the signaled duration can be used to derive a timing advance for uplink transmission. Optionally, the uplink transmission includes a PRACH transmission, or a PUSCH transmission scheduled by a RAR UL grant, or a PUCCH transmission, or a SRS transmission. Optionally, the PUCCH transmission includes a PUCCH transmission scheduled by DCI or scheduled by successRAR according to TS38.213 section 8.2A with CRS scrambled with MsgB-RNTI. While the present disclosure has been described in connection with what is considered the most practical and preferred embodiments, it is understood that the present disclosure is not limited to the disclosed embodiments but is intended to cover various arrangements made without departing from the scope of the broadest interpretation of the appended claims.

Example 4

For the MAC CE action timing, the corresponding action and the UE assumption on the downlink configuration indicated by the MAC-CE command shall be applied starting from the earliest slot that is after slot n+X, where the HARQ-ACK corresponding to a PDSCH carrying a MAC-CE command is transmitted in slot n and the value of X = 0(max(Tl, T2)), and T1 is a first time interval of 3 milliseconds, and T2 is a second time corresponding to the offset or the first offset or the second offset according to examples 1 or 2 or 3 in unit of milliseconds, and O(.) is an operation to convert time interval to a number of slots. The conversion from time interval to a number of slots is based on the subcarrier spacing of active DL BWP or active UL BWP or a reference subcarrier spacing.

Claims

1. A method of communication of a user equipment (UE), comprising:

Receiving a first information; the first information is used to determine a second information.

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