User terminal, base station and radio communication method

• US 10,090,988 B2
• Filed: 09/19/2014
• Issued: 10/02/2018
• Est. Priority Date: 09/26/2013
• Status: Active Grant

• Current Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Original Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Inventors: Takeda, Kazuki, Ishii, Hiroyuki
• Primary Examiner(s): Elpenord, Candal
• Application Number:
  US15/024,976
• Publication Number:
  US 20160234004A1
• Time in Patent Office: 1,474 Days
• Field of Search: None
• CPC Class Codes: H04L 1/1854 Scheduling and prioritising arrangements
• CPC Class Codes: H04L 5/001 the frequencies being arranged in component carriers
• CPC Class Codes: H04L 5/0055 Physical resource allocation for ACK/NACK for physical mapping arrangements in ARQ protocols H04L1/1861
• CPC Class Codes: H04L 5/14 Two-way operation using the same type of signal, i.e. duplex
• CPC Class Codes: H04L 5/1469 using time-sharing
• CPC Class Codes: H04W 72/0446 Resources in time domain, e.g. slots or frames
• CPC Class Codes: H04W 72/21 in the uplink direction of a wireless link, i.e. towards the network

Abstract

The present invention is designed so that uplink transmission is carried out adequately even when CA to apply different duplex modes between multiple cells is executed. A user terminal communicates with an FDD cell and a TDD cell by employing carrier aggregation, and has a receiving section that receives DL signals transmitted from each cell, and a feedback control section that allocates delivery acknowledgement signals in response to the DL signals received, by allocating the delivery acknowledgment signals in a predetermined UL subframe, and, regardless of the cell that is configured as the primary cell, when UL subframes are configured in both the FDD cell and the TDD cell, the feedback control section feeds back the delivery acknowledgement signals by using a UL subframe of one or both of the cells, and, when a UL subframe is configured only in the FDD cell, the feedback control section feeds back the delivery acknowledgement signals by using the UL subframe of the FDD cell.

Claims

1. A user terminal that communicates with a Frequency Division Duplex (FDD) cell and a Time Division Duplex (TDD) cell by employing carrier aggregation, the user terminal comprising:

a receiver that receives DL signals transmitted from each of the FDD cell and the TDD cell; and

a processor that allocates delivery acknowledgement signals in response to the DL signals received, by allocating the delivery acknowledgment signals in a predetermined UL subframe,

wherein, regardless of whether the FDD cell or the TDD cell is configured as a primary cell, when UL subframes are configured in both of the FDD cell and the TDD cell, the processor feeds back the delivery acknowledgement signals in response to the DL signal from the FDD cell and the DL signal from the TDD cell independently by using respective UL control channels of the FDD cell and TDD cell, and, when a UL subframe is configured only in the FDD cell, the processor feeds back the delivery acknowledgement signals using the UL control channel of the FDD cell, and feedback is not carried out in the TDD cell.

2. The user terminal according to claim 1, wherein the processor applies a same Hybrid Automatic Repeat Request (HARD) timing when the FDD cell and the TDD cell are scheduled by different schedulers and the same HARQ timing when the FDD cell and the TDD cell are scheduled by a same scheduler.

3. The user terminal according to claim 1, wherein, when the UL subframes are configured in both of the FDD cell and the TDD cell, the receiver receives downlink control information (DCI) that includes information of the UL control channels of the respective cells.

4. A base station that communicates with a user terminal by employing carrier aggregation with a Frequency Divison Duplex (FDD) cell and a Time Division Duplex (TDD) cell, the base station comprising:

a transmitter that transmits a DL signal from each of the FDD cell and the TDD cell;

and

a receiver that receives, in a predetermined UL subframe, a delivery acknowledgement signal that is transmitted from the user terminal in response to the DL signal transmitted from the user terminal,

wherein, regardless of whether the FDD cell or the TDD cell is configured as a primary cell, when UL subframes are configured in both of the FDD cell and the TDD cell, the receiver receives the delivery acknowledgement signals fed back in response to the DL signal from the FDD cell and the DL signal from the TDD cell independently by using respective UL control channels of the FDD cell and TDD cell, and, when a UL subframe is configured only in the FDD cell, the receiver receives the delivery acknowledgement signals fed back using the UL control channel of the FDD cell and feedback is not carried out in the TDD cell.

5. A radio communication method for a user terminal that communicates with a Frequency Division Duplex (FDD) cell and a Time Division Duplex (TDD) cell by employing carrier aggregation, the radio communication method comprising the steps of:

receiving DL signals transmitted from each of the FDD cell and the TDD cell; and

allocating delivery acknowledgement signals in response to the DL signals received, by allocating the delivery acknowledgment signals in a predetermined UL subframe,

wherein, regardless of whether the FDD cell or the TDD cell is configured as a primary cell, when UL subframes are configured in both of the FDD cell and the TDD cell, the delivery acknowledgement signals are fed back in response to the DL signal from the FDD cell and the DL signal from the TDD cell independently by using respective UL control channels of the FDD cell and TDD cell, and, when a UL subframe is configured only in the FDD cell, the delivery acknowledgement signals are fed back using the UL control channel of the FDD cell, and feedback is not carried out in the TDD cell.