Patent ID: 7593486

Claim:
A receiver in a multiple-input multiple-output (MIMO) mobile communication system, comprising: an error checker for checking errors in received data and outputting an error check result; and a feedback portion for adaptively changing a threshold associated with a channel state according to the error check result, determining a transmission mode by comparing the changed threshold with a measured channel quality indicator (CQI), and feeding back information related to a transmission mode to a transmitter; wherein, in a first operation mode, the feedback portion uses a threshold calculated under a severe-distortion channel environment as an initial threshold, non-linearly decreases an existing threshold if the error check result is an acknowledgement (ACK) and the existing threshold is greater than or equal to a first predetermined reference value, linearly decreases the existing threshold if the error check result is an ACK and the existing threshold is less than the predetermined reference value, and changes the existing threshold to the initial threshold if the error check result is a non-acknowledgement (NACK).