USER TERMINAL, BASE STATION AND RADIO COMMUNICATION METHOD

• US 20160242158A1
• Filed: 09/22/2014
• Published: 08/18/2016
• 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, Harada, Hiroki, Nagata, Satoshi, Ishii, Hiroyuki
• Granted Patent: US 10,462,781 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04L 1/18 Automatic repetition systems, e.g. Van Duuren systems
• 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 72/044 based on the type of the allocated resource
• 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

Abstract

The present invention is designed to carry out uplink transmission adequately even when CA is executed by applying different duplex modes between multiple cells. A user terminal communicates with an FDD cell and a TDD cell that employ carrier aggregation, and has a receiving section that receives DL signals transmitted from each cell, and a feedback control section that allocates and feeds back delivery acknowledgement signals in response to the DL signals in a predetermined UL subframe, and, regardless of which cell is configured as a primary cell, the feedback control section, when transmitting only a delivery acknowledgement signal in response to the DL signal of one cell, transmits the delivery acknowledgement signal from the one cell by using a PUCCH resource that is determined from a downlink control channel resource of the DL signal, and, when transmitting delivery acknowledgement signals in response to the DL signals of both cells, transmits the delivery acknowledgement signals by using a PUCCH resource of one or both of the cells.

Claims

1. A user terminal that communicates with an FDD cell and a TDD cell employing carrier aggregation, the user terminal comprising:

a receiving section that receives DL signals transmitted from each cell; and

a feedback control section that allocates and feeds back delivery acknowledgement signals in response to the DL signals in a predetermined UL sub frame,

wherein, regardless of which cell is configured as a primary cell, the feedback control section, when transmitting only a delivery acknowledgement signal in response to the DL signal of one cell, transmits the delivery acknowledgement signal from the one cell by using a PUCCH resource that is determined from a downlink control channel resource of the DL signal, and, when transmitting delivery acknowledgement signals in response to the DL signals of both cells, transmits the delivery acknowledgement signals by using a PUCCH resource of one or both of the cells.

2. The user terminal according to claim 1, wherein, when transmitting the delivery acknowledgement signals in response to the DL signals from both cells, the feedback control section applies a PUCCH format 1b with channel selection or a PUCCH format 3 and uses the PUCCH resource of one cell.

3. The user terminal according to claim 2, wherein the feedback control section uses bit information contained in downlink control information of a secondary cell as an ARI, and determines the PUCCH resource to use in the PUCCH format 1b with channel selection or in the PUCCH format 3.

4. The user terminal according to claim 2, wherein the feedback control section applies the PUCCH format 1b with channel selection by using a PUCCH resource candidate that is determined based on a downlink control channel resource where downlink control information of a primary cell is contained, and a PUCCH resource candidate that is determined based on a downlink control channel resource where downlink control information of a secondary cell is contained.

5. The user terminal according to claim 2, wherein the feedback control section selects a specific PUCCH resource, from a plurality of PUCCH resource candidates that are configured by higher layer signaling, based on a signal configuration of downlink control information of a primary cell or a secondary cell.

6. The user terminal according to claim 1, further comprising a power control section that controls transmission power of a UL signal that is transmitted in a PUCCH,

wherein, when the receiving section detects only downlink control information of a secondary cell, the power control section limits application of a TPC command contained in the downlink control information.

7. The user terminal according to claim 6, wherein, for a delivery acknowledgement signal that is transmitted by using a PUCCH resource of the secondary cell, the power control section executes power control by using the TPC command that is contained in a UL grant in the downlink control information of the secondary cell.

8. The user terminal according to claim 6, where, for a delivery acknowledgement signal that is transmitted by using a PUCCH resource of the secondary cell, the power control section executes power control by using a TPC command that is contained in a DCI format 3/3A of the primary cell.

9. A base station that communicates with a user terminal by employing carrier aggregation with another base station to use a different duplex mode, the base station comprising:

a generating section that generates a DL signal;

a transmission section that transmits the DL signal to the user terminal in a DL subframe; and

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

wherein the transmission section reports PUCCH resources in a primary cell and a secondary cell as PUCCH resource candidates to use when the user terminal employs a PUCCH format 1b with channel selection or a PUCCH format 3.

10. A radio communication method for a user terminal that communicates with an FDD cell and a TDD cell employing carrier aggregation, the radio communication method comprising the steps of:

receiving DL signals transmitted from each cell; and

allocating and feeding back delivery acknowledgement signals in response to the DL signals in a predetermined UL subframe,

wherein, regardless of which cell is configured as a primary cell, when only a delivery acknowledgement signal in response to the DL signal of one cell is transmitted, transmitting the delivery acknowledgement signal from the one cell by using a PUCCH resource that is determined from a downlink control channel resource of the DL signal, and, when delivery acknowledgement signals in response to the DL signals of both cells are transmitted, transmitting the delivery acknowledgement signals by using a PUCCH resource of one or both of the cells.