Patent ID: 8792436

Claim:
A method of supporting multiple system modes in a wireless communication system, the method performed by a user equipment (UE) and comprising: receiving a radio resource control (RRC) signal from a base station, wherein the RRC signal indicates at least one first type subframe in which the UE operates in a long term evolution (LTE) mode and at least one second type subframe in which the UE operates in an LTE-Advanced (LTE-A) mode; receiving first type downlink data in the at least one first type subframe, wherein the first type downlink data is received through a maximum of four transmit antennas of the base station; receiving second type downlink data in the at least one second type subframe, wherein the second type downlink data is received through a maximum of eight transmit antennas of the base station; generating a first type feedback value indicating channel status associated with the first type downlink data, wherein the first type feedback value is delivered to the base station based on a first feedback cycle; generating a second type feedback value indicating channel status associated with the second type downlink data, wherein the second type feedback value is delivered to the base station based on a second feedback cycle set to be shorter than the first feedback cycle; transmitting first type uplink data in the at least first type subframe, wherein the first type uplink data is transmitted by a single antenna of a plurality of antennas of the UE; and transmitting second type uplink data in the at least one second type subframe, wherein the second type uplink data is transmitted by the plurality of antennas of the UE.