Method for transmitting ack/nack information and method for receiving ack/nack information, user device, and base station

The present invention relates to a transmission diversity technique for channel selection. According to the present invention, even if a transmission device transmits a signal using channel selection through a plurality of antenna ports, the overhead of a resource for channel selection, which occurs in proportion to the number of antennas, is reduced. Additionally, as the number of antenna ports participating in signal transmission is increased, multiplex capacity is reduced. According to the present invention, the degree to which the multiplex capacity is reduced according to the increase in the number of antenna ports is decreased.