A wireless communication system using pilot subcarrier allocation and a method of allocating the pilot subcarriers for use in downlink and uplink communication in a multiple-input multiple-output (MIMO) antenna system using orthogonal frequency division multiplexing (OFDM) modulation are disclosed. The method includes providing a frame structure comprising OFDM symbols in time domain and subcarriers in frequency domain and alternately allocating first pilot subcarriers for a first antenna and second pilot subcarriers for a second antenna in the time and frequency domains, wherein each of the alternating first pilot subcarriers and the second pilot subcarriers is separated by multiple of 9 subcarriers in the frequency domain and further allocated in two contiguous OFDM symbols.