Abstract—In this paper, MIMO (Multiple-Input-Multiple Output) system based on turbo equalization techniques which LDPC (Low Density Parity Check) codes were outer code and STTC (Space Time Trellis Code) were employed as an inner code are studied. LDPC decoder and STTC decoder are connected through the interleaving and de-interleaving that updates each other's information repeatedly. On the receiver side, in processing the turbo equalization with STTC decoder, in order to feed extrinsic information to STTC decoder, the extrinsic information of LDPC decoder must be two bit processing. However LDPC codes can't be applied to these system because LDPC decoder require just one bit processing. Therefore this paper proposes a turbo equalization model for LDPC codes able to apply MIMO systems combined with STTC codes. Through simulation results, we show that the performance of the proposed turbo equalization model is improved about 2.5 dB than that of turbo codes and about 10.5dB than that of conventional scheme.