| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a communications system in which sub-carriers for transmitting uplink data to a base station are allocated to user devices. <P>SOLUTION: ACK/NACK messages for data transmitted on the uplink are transmitted by the base station on sub-carriers that depend on the sub-carriers used to carry the uplink data. A direct mapping function is preferably used to determine the sub-carriers to be used for the ACK/NACK messages from the uplink sub-carriers. In another embodiment, the ACK/NACK messages are transmitted to the user devices on sub-carriers that are previously identified to the user devices, preferably by transmitting one or more index values to the individual user devices in a control channel thereof. <P>COPYRIGHT: (C)2012,JPO&INPIT |
