Patent ID: 7843889

Claim:
A Base Station (BS) of a Space Division Multiple Access (SDMA) communication system, the BS comprising: an antenna weighting calculator for differentially allocating a transmission power to each Mobile Station (MS) depending on a channel state of each of a plurality of MSs; wherein when differentially allocating the transmission power to each MS, the antenna weighting calculator divides the transmission power of the BS by number of MSs to be allocated, fixedly distributes the divided transmission powers to the MSs, calculates a surplus power of each MS, sums up the calculated surplus power of each MS to thereby calculate a total surplus power, calculates a power per MS needed for a Modulation order Product code Rate (MPR) one level higher, determines whether there is an MS whose power needed for the MPR one level higher is smaller than the total surplus power of the BS among the MSs, and additionally allocates the total surplus power to the MS when it is determined that there is the MS; and a plurality of antennas for transmitting corresponding data to the each MS according to the allocated transmission power to the each MS by the antenna weighting calculator.