Frame transmission method using precoding for supporting MU-MIMO, and base station supporting the frame transmission method

A transmitter configured for transmitting data in a wireless communication system, comprising:

• a precoder configured to:
• determine a channel precoding matrix based on channel state information received from a receiver;
• determine a current precoding matrix based on a previous precoding matrix stored in a memory and the channel precoding matrix;
• and
• precode data with the current precoding matrix;
• and
• store the current precoding matrix as the previous precoding matrix into the memory;
• and
• a transmitting unit configured to transmit the precoded data to the receiver via a plurality of antennas,
• wherein the precoder is further configured to precode the data and a dedicated pilot with the current precoding matrix,
• wherein the transmitting unit is configured to transmit the precoded data and the precoded dedicated pilot to the receiver via the plurality of antennas, and
• wherein the channel state information is created by multiplying the precoded dedicated pilot received by the receiver and the dedicated pilot.

A frame receiving method using precoding for supporting multi-user multi-input multi-output (MU-MIMO), comprising:

• receiving precoded data and a precoded dedicated pilot transmitted from a base station which uses a plurality of antennas;
• performing data detection using the received precoded dedicated pilot;
• creating channel state information by multiplying the received precoded dedicated pilot and a dedicated pilot;
• and
• transmitting the channel state information to the base station,
• wherein creating channel state information comprises creating the channel state information by multiplying the received precoded dedicated pilot and a dedicated pilot, and wherein the precoded data transmitted from the base station is generated by:
• determining a channel precoding matrix based on channel state information received from a receiver;
• determining a current precoding matrix based on a previous precoding matrix stored in a memory and the channel precoding matrix;
• and
• precoding data with a current precoding matrix.