Method and device for transmitting ACK/NACK in carrier aggregating system
AssigneeLG Electronics Inc.
InventorsDongyoun Seo, Bonghoe Kim, Joonkui Ahn, Suckchel Yang
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Abstract
The present invention relates to a method of transmitting an acknowledgement/not-acknowledgement (ACK/NACK) and a device for using such a method. According to the present invention, a cell-specific downlink-uplink setting for one of a plurality of serving cells and a reference UL-DL setting is received, an effective downlink sub-frame capable of actually receiving a data unit from one serving cell is determined based on the settings, and only an ACK/NACK for the effective downlink sub-frame is configured as a bit string and fed back.
Claims8
A method of transmitting acknowledgement (ACK)/not-acknowledgement (NACK) of a user equipment configured with a plurality of serving cells, the method comprising:
- receiving a cell-specific uplink (UL)-downlink (DL) configuration for a secondary cell among the plurality of serving cells,
- wherein the cell-specific UL-DL configuration is information which configures subframes in a frame of the secondary cell to a UL subframe or a DL subframe;
- receiving a reference UL-DL configuration for the secondary cell,
- wherein the reference UL-DL configuration is information which indicates an ACK/NACK transmission time by configuring the subframes in the frame to the UL subframe or the DL subframe;
- determining valid DL subframes capable of actually receiving a data unit in the secondary cell on the basis of the cell-specific UL-DL configuration and the reference UL-DL configuration;
- and
- constructing ACK/NACK only for the valid DL subframes in a form of a bit-stream and feed-backing the bit-stream,
- wherein the reference UL-DL configuration for the secondary cell is a cell-specific UL-DL configuration for a primary cell, and
- wherein, when the primary cell uses a time division duplex (TDD) frame and the secondary cell uses a frequency division duplex (FDD) frame, a DL subframe which overlaps with a UL subframe of the TDD frame among DL subframes included in the FDD frame is excluded from the valid DL subframes.
A user equipment comprising:
- a radio frequency (RF) unit for transmitting and receiving a radio signal;
- and
- a processor operatively coupled to the RF unit,
- wherein the processor is configured for:
- receiving a cell-specific uplink (UL)-downlink (DL) configuration for a secondary cell among the plurality of serving cells,
- wherein the cell-specific UL-DL configuration is information which configures subframes in a frame of the secondary cell to a UL subframe or a DL subframe;
- receiving a reference UL-DL configuration for the secondary cell,
- wherein the reference UL-DL configuration is information which indicates an ACK/NACK transmission time by configuring the subframes in the frame to the UL subframe or the DL subframe;
- determining valid DL subframes capable of actually receiving a data unit in the secondary cell on the basis of the cell-specific UL-DL configuration and the reference UL-DL configuration;
- and
- constructing ACK/NACK only for the valid DL subframes in a form of a bit-stream and feed-backing the bit-stream,
- wherein the reference UL-DL configuration for the secondary cell is a cell-specific UL-DL configuration for a primary cell, and
- wherein, when the primary cell uses a time division duplex (TDD) frame and the secondary cell uses a frequency division duplex (FDD) frame, a DL subframe which overlaps with a UL subframe of the TDD frame among DL subframes included in the FDD frame is excluded from the valid DL subframes.
Dependencies are inferred from the claim text.