Patent ID: 8380212

Claim:
A base station apparatus for a base station in a wireless communications system, the base station apparatus comprising: a first channel state information receiving unit to receive first channel state information from a plurality of terminals regarding a wireless channel between the base station apparatus and the plurality of terminals connected to the base station apparatus, wherein the first channel state information is quantized based on a first quantization length; a receiving terminal selection unit to select at least one receiving terminal to receive data from among the plurality of terminals based on the first channel state information; a quantization length determination unit to independently determine a second quantization length of the selected receiving terminal based on the first channel state information; a quantization length transmission unit to transmit the second quantization length to the selected receiving terminal, wherein the second quantization length corresponds to the selected receiving terminal; a second channel state information receiving unit to receive the second channel state information from the selected receiving terminal, wherein the second channel state information is quantized based on the second quantization length of the wireless channel; and a data transmission unit to transmit data to the selected receiving terminal using a plurality of transmission antennas of the base station based on the second channel state information.