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BR-112020008456-B1 - TERMINAL AND TRANSMISSION METHOD TO A TERMINAL

BR112020008456B1BR 112020008456 B1BR112020008456 B1BR 112020008456B1BR-112020008456-B1

Abstract

This refers to the ability to appropriately control the transmission timing of an uplink signal to which a plurality of numerologies is applied. A user terminal includes a receiving section that receives a Medium Access Control Element (MAC CE) including a timing index from a base station, a control section that adjusts the transmission timing of an uplink signal based on a value obtained by multiplying the timing index with a granularity corresponding to a signal design of the uplink signal, and a transmitting section that transmits the uplink signal whose transmission timing has been adjusted to the base station.

Inventors

  • Tooru Uchino
  • Hideaki Takahashi
  • Kazuki Takeda
  • Tomoya OHARA
  • Hiroki Harada

Assignees

  • NTT DOCOMO, INC

Dates

Publication Date
20260317
Application Date
20171031

Claims (4)

  1. 1. Terminal (2a) characterized in that it comprises: a control section (25) configured to adjust an uplink transmission timing based on granularity relative to a larger subcarrier spacing among subcarrier spacings of a plurality of uplink bandwidth portions in the same timing advance group and based on a timing advance command; and a transmission section (21) configured to perform uplink transmission according to the uplink transmission timing, wherein the granularity relative to the subcarrier spacing of the uplink bandwidth portion becomes small as the subcarrier spacing of the uplink bandwidth portion becomes large, and wherein the control section is configured to adjust the uplink transmission timing using a value obtained by multiplying the timing advance command by the granularity relative to the larger subcarrier spacing.
  2. 2. Terminal (2a), according to claim 1, characterized in that the plurality of uplink bandwidth parts is in two uplink carriers of a server cell.
  3. 3. Terminal (2a), according to claim 1 or 2, characterized in that the granularity relative to the largest subcarrier spacing is smaller than the granularity relative to a subcarrier spacing smaller than the largest subcarrier spacing.
  4. 4. Transmission method for a terminal (2a) characterized in that it comprises steps performed by the terminal of: adjusting an uplink transmission timing based on granularity relative to a larger subcarrier spacing among subcarrier spacings of a plurality of uplink bandwidth portions in the same timing advance group and based on a timing advance command; and performing uplink transmission in accordance with the uplink transmission timing, wherein the granularity relative to the subcarrier spacing of the uplink bandwidth portion becomes small as the subcarrier spacing of the uplink bandwidth portion becomes large, and wherein the control section is configured to adjust the uplink transmission timing using a value obtained by multiplying the timing advance command by the granularity relative to the larger subcarrier spacing.

Description

FIELD OF TECHNIQUE [001] The present invention relates to a user terminal and a method for controlling transmission timing. BACKGROUND OF THE TECHNIQUE [002] Long Term Evolution (LTE) was specified to achieve higher data rates, lower latency, and the like in a Universal Mobile Telecommunications System (UMTS) network (see Non-Patent Literature (hereinafter referred to as "NPL") 1). LTE successor systems have been studied to achieve wider bandwidth and higher speeds based on LTE. Examples of LTE successor systems include, for example, systems called LTE Advanced (LTE-A), Future Radio Access (FRA), 5G mobile communication system, 5G plus (5G+), New Radio Access Technology (Nova-RAT), and the like. [003] In radio communication systems, time alignment is important for suppressing symbol interference from uplink signals. NPLs 2 and 3 define Time Advance (TA) and similar terms used for time alignment. [004] In a next-generation radio communication system, such as 5G, the introduction of a plurality of numerologies has been considered. For example, it is considered that a plurality of Subcarrier Spacings (SCS) be applied to an uplink signal of the next-generation radio communication system. LIST OF CITATIONS Non-Patent Literature NPL 1 [005] T. Okuyama et. al.: "Antenna Deployment for 5G Ultra High-Density Distributed Antenna System at Low SHF Bands" Standards for Communications and Networking (CSCN), 2016, pages. 1 to 6, November 2016, Berlin, Germany NPL 2 [006] 3GPP TS 36.321 v14.3.0, "Evolved Universal Terrestrial Radio Access (E-UTRA); Medium Access Control (MAC) protocol specification (Release 14)”, June 2017 NPL 3 [007] 3GPP TS 36.211 v13.3.0, "Evolved Universal Terrestrial Radio Access (E-UTRA); Physical channels and modulation (Release 13)", September 2016 SUMMARY OF THE INVENTION PROBLEM WITH THE TECHNIQUE [008] However, there is no standard for timing control of uplink signal transmission to which numerology plurality is applied. [009] Consequently, an objective of the present invention is to provide a user terminal and a transmission timing control method for controlling the transmission timing of an uplink signal to which a plurality of numerologies is applied. SOLUTION TO THE PROBLEM [010] A user terminal of the present invention includes: a receiving section that receives a Medium Access Control (MAC CE) Control Element including a timing index from a base station; a control section that adjusts a transmission timing of an uplink signal based on a value resulting from multiplying the timing index with a granularity corresponding to a signal design of the uplink signal; and a transmitting section that transmits, to the base station, the uplink signal whose transmission timing has been adjusted. ADVANTAGEOUS EFFECTS OF THE INVENTION [011] According to the present invention, a transmission timing of an uplink signal to which a plurality of numerologies is applied can be appropriately controlled. BRIEF DESCRIPTION OF THE DRAWINGS [012] Figure 1 is a diagram illustrating an exemplary configuration of a radio communication system according to Mode 1; Figure 2 is a diagram to explain an example of time alignment of an uplink signal; Figure 3 is a diagram illustrating an example of an RA procedure; Figure 4 is a diagram illustrating an exemplary MAC RAR data configuration; Figure 5 is a diagram illustrating an example of a TA command notification using MAC CE TA Command; Figure 6 is a diagram illustrating an exemplary data configuration of the MAC CE TA Command; Figure 7 is a diagram to explain the conversion of the TA command into time; Figure 8A is a diagram to explain an example of numerology; Figure 8B is a diagram to explain an example of numerology; Figure 9 is an exemplary block configuration of a gNB; Figure 10 is an exemplary block configuration of a EU; Figure 11 is a diagram illustrating an exemplary data configuration of a storage section; Figure 12 is a diagram illustrating an example of an RA procedure corresponding to the numerology of the uplink signal; Figure 13 is a diagram illustrating an exemplary data configuration of a MAC CE TA Command corresponding to the numerology of the uplink signal; Figure 14 is a diagram illustrating another exemplary data configuration of a MAC CE TA Command corresponding to the numerology of the uplink signal; Figure 15 is a diagram illustrating yet another exemplary data configuration of a MAC CE TA Command corresponding to the numerology of the uplink signal; Figure 16 is a diagram illustrating an example of LCID values; Figure 17 is a diagram to explain an exemplary operation of a radiocommunication system according to Mode 2; Figure 18 is a diagram to explain an exemplary operation. Figure 19 is a diagram to explain an exemplary operation of a radiocommunication system according to Mode 3; Figure 20A is a diagram to explain an exemplary operation of a radiocommunication system according to Mode 4; Figure 20B is a diagram to explain an exemplary operation