Patent ID: 9461802
Filing Date: 2016-10-04
CPC Classification: H04L,H04W

Claim Text:
1. A method of communicating control information between a base station and a user equipment (UE), the method comprising: establishing a Radio Resource Control (RRC) connection with the base station through a first serving cell, the first serving cell supporting a Time Division Duplex (TDD) mode; receiving 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; checking 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; receiving, at the UE, at least one of a Physical Downlink Control Channel (PDCCH) and an Enhanced PDCCH (EPDCCH), the at least one of the PDCCH and the EPDCCH comprising the DL DCI format; receiving, at the UE, data through the first serving cell and the second serving cell; in response to the received data, generating 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 transmitting the HARQ ACK/NACK signal through the uplink subframe of the first serving cell.