Patent ID: 8422574

Claim:
A base station apparatus capable of communicating with a user equipment terminal in a multi-input multi-output (MIMO) mobile communication system using Pre-coding, the base station apparatus comprising: a receiving unit configured to receive a Pre-coding Matrix Indicator (PMI) indicating a specific Pre-coding matrix; a determination unit configured to determine a value of a flag indicator indicating whether the Pre-coding matrix specified in the PMI is to be used for downlink communications; a control signal generation unit configured to generate a downlink control signal including at least the flag indicator; and a transmission unit configured to transmit a signal including the downlink control signal in downlink, wherein the control signal generation unit is configured to derive error detection information by performing a predetermined calculation on a calculation target including at least control information and the flag indicator, and wherein the control signal generation unit is configured to perform a channel-coding process on a data part including the control information, the flag indicator, and the error detection information by treating the data part as a unit of the channel-coding.