A Modified Grouped Linear ZF Algorithm Using Different Modulation Schemes for MIMO Systems

A new algorithm for a group iterative linear Zero-Forcing (ZF) receiver for multiple-input multiple-output (MIMO) systems is proposed in this paper. The proposed algorithm merges between the group linear ZF receiver and V-Blast algorithms, where the signals in every group are detected by linear ZF method and then successive interference cancellation detection is applied between the different groups. Three types of modulation schemes are adopted for testing this algorithm namely; BPSK, QPSK, and 16 QAM. Simulation results show that the proposed algorithm achieves a performance improvement over the ZF algorithm and the grouped linear ZF algorithm at modulations (BPSK, QPSK). The proposed scheme offers better performance gain for BPSK modulation of about 7dB and 2dB compared with ZF and MMSE schemes respectively at BER of 10. On the other hand, the proposed scheme offer better performance gain of about 3dB and 1dB compared with ZF and minimum mean square error schemes for QPSK modulation at BER 10. However, at using modulation of (16QAM), the performance of the proposed algorithm is almost the same as that of the aforementioned algorithms. A little increase of computational complexity is noticed with this proposed algorithm compared with both the ZF, MMSE and the grouped linear ZF algorithms.