Patent ID: 8140122

Claim:
A method for determining a multi-antenna transmission mode at a base station in a multi-antenna system, the method comprising: when operating in a Multiple Input Multiple Output (MIMO) transmission mode as a multi-antenna transmission mode, determining a reference set point; updating a set point for transmit power control of a terminal according to an error occurrence in a signal received from the terminal; determining whether a channel to the terminal is a channel for applying the MIMO transmission mode by comparing the updated set point with the reference set point; and when the channel to the terminal is not the channel for applying the MIMO transmission mode, changing the multi-antenna transmission mode to a fixed transmission mode, wherein the reference set point comprises a value for determining whether the channel to the terminal is the channel for applying the MIMO transmission mode, and the fixed transmission mode is a multi-antenna transmission mode operating in a Single Input Multiple Output (SIMO) transmission mode during a reference time.