METHOD AND APPARATUS FOR ACQUIRING HYBRID AUTOMATIC REPEAT FEEDBACK AND COMMUNICATIONS SYSTEM

摘要

A method and apparatus for acquiring hybrid automatic repeat feedback and a communications system. The method includes: transmitting uplink data in a certain uplink subframe and in a secondary serving cell at an unlicensed band; setting a variable for recording a feedback status of transmission of the uplink data as ACK in transmitting the uplink data; determining a downlink subframe corresponding to the uplink subframe; and decoding a PDCCH in the downlink subframe corresponding to the uplink subframe in the secondary serving cell at the unlicensed band, and not decoding a PHICH. After the user equipment transmits the uplink data in the serving cell at the unlicensed band, the user equipment may be guaranteed in correctly performing uplink transmission even though the subframe needed by the base station for transmitting the PHICH is occupied by another system.