USER TERMINAL, RADIO BASE STATION, AND RADIO COMMUNICATION METHOD

• US 20180020445A1
• Filed: 02/19/2016
• Published: 01/18/2018
• 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
• Granted Patent: US 10,512,067 B2
• Time in Patent Office: Days
• 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 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,

wherein, 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.

2. The user terminal according to claim 1, wherein the control section transmits UL data by using padding bits when it is judged that there is no UL data that corresponds to a UL grant in the first CC or the second CC, and does not transmit the UL data when it is judged that there is no UL data that corresponds to the UL grant in the third CC.

3. The user terminal according to claim 2, wherein the transmission section includes and transmits information that indicates that there is no UL data that corresponds to the UL grant in the third CC, in a UL signal of the first CC and/or the second CC.

4. The user terminal according to claim 1, wherein the control section applies asynchronous HARQ to UL signals transmitted in the third CC.

5. The user terminal according to claim 4, wherein, when a UL grant to command UL signal transmission in the third CC is received in the receiving section, the control section controls a PHICH (Physical Hybrid-ARQ Indicator Channel) not to be detected in the third CC.

6. The user terminal according to claim 5, wherein the control section applies retransmission control to the UL signal transmitted in the third CC based on a HARQ process number that is include in the UL grant.

7. The user terminal according to claim 1, wherein, when a UL grant to command UL signal transmission in the third CC is received in the receiving section, the control section executes listening in a plurality of third CCs that are configured in advance, and, based on results of listening, transmits UL signals in a predetermined third CC.

8. The user terminal according to claim 1, wherein, when a UL grant to command UL signal transmission in the third CC is received in the receiving section, the control section reports a predetermined PHR (Power Headroom Report) to the radio base station, as a PHR for the third CC, regardless of a result of listening.

9. 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 DL signals transmitted from each CC; and

transmitting UL signals,

wherein, 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, UL signal transmission operations that are different from those of the second CC are applied to the third CC.

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

a transmission section that transmits DL signals in each CC; and

a control section that controls allocation of UL signals;

wherein, 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 in the user terminal, the control section allocates resources for a plurality of third CCs at the same time, from one of the first CC and/or the second CC.