Patent ID: 7764744

Claim:
A communication method in a Base Station (BS) in a wireless communication system that services a first multiple antenna mode using X transmit antennas comprising an antenna group A and a second multiple antenna mode using Y transmit antennas comprising a combination of the antenna group A and an antenna group B where (Y>X), comprising the steps of: determining a Mobile Station (MS) to be serviced in the second multiple antenna mode; receiving a sounding signal from the MS; estimating an uplink channel using the received sounding signal and acquiring downlink channel values using estimated uplink channel values; and servicing the MS in the second multiple antenna mode using the downlink channel values, wherein the X transmit antennas of the antenna group A are utilized to send all control information, every pilot, every preamble, and data signals for at least one MS in the first multiple antenna mode and data signals for at least one MS in the second multiple antenna mode, and wherein the difference between Y and X transmit antennas (Y−X) comprising the antenna group B are utilized to send only data signals for at least one MS in the second multiple antenna mode.