User terminal, radio base station, and radio communication method

• US 10,512,067 B2
• Filed: 02/19/2016
• Issued: 12/17/2019
• Est. Priority Date: 02/19/2015
• Status: Active Grant

• Current Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Original Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Inventors: Harada, Hiroki, Takeda, Kazuki, Takeda, Kazuaki, Uchino, Tooru, Nagata, Satoshi
• Primary Examiner(s): Lopata, Robert J
• Application Number:
  US15/548,460
• Publication Number:
  US 20180020445A1
• Time in Patent Office: Days
• Field of Search: 370329
• CPC Class Codes: H04J 1/00 Frequency-division multiplex systems H04J14/00 takes precedence
• CPC Class Codes: H04J 11/00 Orthogonal multiplex systems, e.g. using WALSH codesH04J13/00 takes precedence
• CPC Class Codes: H04L 1/1812 Hybrid protocols; Hybrid automatic repeat request [HARQ]
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks
• CPC Class Codes: H04W 52/365 Power headroom reporting
• CPC Class Codes: H04W 72/04 Wireless resource allocation
• CPC Class Codes: H04W 72/12 Wireless traffic scheduling
• CPC Class Codes: H04W 72/1268 of uplink data flows
• CPC Class Codes: H04W 72/21 in the uplink direction of a wireless link, i.e. towards the network
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal
• CPC Class Codes: H04W 74/08 Non-scheduled access, e.g. ALOHA hybrid access H04W74/02
• CPC Class Codes: H04W 88/02 Terminal devices
• CPC Class Codes: H04W 88/08 Access point devices

Abstract

The present invention is designed to allow adequate communication even when the number of CCs that can be configured in a user terminal is expanded from that of existing systems and/or when CA is executed using unlicensed CCs. A user terminal communicates with a radio base station by means of carrier aggregation using a plurality of component carriers (CCs), and has a receiving section that receives DL signals transmitted from each CC, a transmission section that transmits UL signals, and a control section that controls transmission operations in the transmission section, and, when a plurality of CCs, including at least a first CC, which corresponds to a primary CC of an existing system, and a third CC, which is different from the first CC and a second CC that corresponds to a secondary CC of the existing system, are configured, the control section applies, to the third CC, UL signal transmission operations that are different from those of the second CC.

Claims

1. A user terminal that communicates with a radio base station by means of carrier aggregation using a plurality of component carriers (CCs), the user terminal comprising:

a receiver that receives downlink (DL) signals transmitted from each of the CCs;

a transmitter that transmits uplink (UL) signals; and

a processor that, when the user terminal is configured with a secondary CC where listen-before-talk (LBT) is applied before transmission and when the user terminal receives downlink control information for scheduling the UL signal in the secondary CC, computes Power Headroom (PH) irrespective of a listening result of the LBT,

wherein the processor computes the PH based on a case in which the user terminal transmits the UL signal by a Physical Uplink Shared Channel (PUSCH), and

when the receiver receives the downlink control information, the processor controls not to detect a Physical Hybrid-ARQ Indicator Channel (PHICH) in the secondary CC.

3. The user terminal according to claim 1, wherein the processor controls retransmission of the UL signal transmitted in the secondary CC, based on a Hybrid Automatic Repeat Request (HARQ) process number included in the downlink control information.

2. A radio communication method in a user terminal that communicates with a radio base station by means of carrier aggregation using a plurality of component carriers (CCs), the radio communication method comprising the steps of:

receiving downlink (DL) signals transmitted from each of the CCs; and

transmitting an uplink (UL) signal,

when the user terminal is configured with a secondary CC where listen-before-talk (LBT) is applied before transmission and when the user terminal receives downlink control information for scheduling the UL signal in the secondary CC, computing Power Headroom (PH) irrespective of a listening result of the LBT,

wherein the user terminal computes the PH based on a case in which the user terminal transmits the UL signal by a Physical Uplink Shared Channel (PUSCH), and

when the user terminal receives the downlink control information, the user terminal controls not to detect a Physical Hybrid-ARQ Indicator Channel (PHICH) in the secondary CC.