Patent ID: 9571255
Date: 2017-02-14
CPC Classifications: H04L,H04W

Claim:
1. A User Equipment (UE) comprising: a transceiver; and a processor operationally coupled to the transceiver and configured to establish a Radio Resource Control (RRC) connection with a base station through a first serving cell, the first serving cell supporting a Time Division Duplex (TDD) mode, wherein: the transceiver receives an RRC message from the base station through the first serving cell, the RRC message comprising carrier aggregation (CA) configuration information, the CA configuration information comprising information of a second serving cell supporting a Frequency Division Duplex (FDD) mode, and the first serving cell and the second serving cell being aggregated by a TDD-FDD CA scheme; the processor is further configured to check a 2-bit downlink (DL) downlink assignment index (DAI) field configured in a DL downlink control information (DCI) format, the DL DCI format indicating a Physical Downlink Shared Channel (PDSCH) transmission on the second serving cell, and the 2-bit DL DAI field indicating that ten downlink subframes for the second serving cell are associated with a uplink subframe of the first serving cell, wherein the DL DCI format is comprised in at least one of a Physical Downlink Control Channel (PDCCH) and an Enhanced PDCCH (EPDCCH); the transceiver receives data through the first serving cell and the second serving cell; in response to the received data, the processor is further configured to generate a Hybrid Automatic Repeat reQuest (HARQ) Acknowledgement/Negative Acknowledgement (ACK/NACK) signal, the HARQ ACK/NACK signal being indexed based on a value of the 2-bit DL DAI field; and the transceiver transmits the HARQ ACK/NACK signal through the uplink subframe of the first serving cell.