A method and an apparatus for using an Adaptive Modulation and Coding (AMC) scheme together with a method of controlling a transmitting power to increase a data transfer rate. The method of transmitting data in a transmitter including a plurality of antennas, includes receiving a Received Signal Strength (RSS) from a receiving portable terminal and determining whether data can be transmitted at the RSS; if the data cannot be transmitted at the RSS, integrating transmitting powers allocated to the plurality of antennas into one antenna to transmit the data when the data cannot be transmitted at the RSS; and transmitting the data using an AMC scheme when the data can be transmitted at the RSS.