— Broadband wireless packet access will be the core technology of the next generation mobile communication systems. For very high-speed and high-quality packet transmissions, the joint use of multiple-input multiple-output (MIMO) multiplexing and hybrid ARQ (HARQ) is very effective. However, if single-carrier (SC) transmission is used, the transmission performance significantly degrades due to a large inter-symbol interference (ISI) resulting from a severe frequency-selective fading. Recently, we proposed a frequencydomain iterative parallel interference cancellation (PIC) for SCMIMO multiplexing. For signal separation, 2 dimensional minimum mean square error (2D MMSE)-FDE is performed at first. Then, the joint PIC and 1D MMSE-FDE is repeated a sufficient number of times. However, the interference from other transmit antennas still remains at the outputs of PIC. Therefore, in this paper, we propose to use 2D MMSE-FDE instead of 1D MMSE-FDE in each iteration and investigate, by comput...