Spatial Division Multiplexing (SDM) technique combined with Space-Time Block Coding(STBC) from multiple antennas can achieve high data rates for digital transmission in Multiple Input Multiple Output(MIMO) system. However, the transmit capacity has reached its limitations for the bandwidth, thus, enhancing digital transmission efficiency becomes reality. Bit-interleaved coded modulation (BICM) can provide spatial diversity which is one of the key techniques for transmission, and can get better coding gains without increasing the bandwidth. Meanwhile, STBC which is the technique of temporal is applied to raise transmission reliability. In this paper, BICM is utilized to be embedded into spatial division multiplexing of two Alamouti codes, which would lead to coding gains and not increase the bandwidth. The simulation results show when BER is below 10
, the improved channel coding scheme can achieve about 1~2 coding gains over Rayleigh fading channels.