In this paper, we propose a new groupwise receiver combiner design method for spatial multiplexing multiple-input multiple-output (MIMO) systems. The conventional group detection (GD) suffers from a considerable performance loss since the noise components are not taken into account. The proposed method further enhances the detection performance than the conventional GD by considering the noise correlation. To prevent the noise enhancement problem, the proposed combiner design utilizes a signal-to-interference-plus-noise ratio (SINR) maximization criterion for each desired subgroup. In addition, we investigate an effect of group selection based on the received SINR. The simulation results show that the proposed scheme achieves a performance gain of 4dB at a frame error rate (FER) of 10-2 over the conventional GD with four transmit and four receive antennas.