Analysis of BER Reduction in QPSK Modulation using V-Blast Algorithms for MIMO System

In wireless communications, spectrum is a scarce resource and hence imposes a high cost on the high data rate transmission. Fortunately, the emergence of multiple antenna system has opened another very resourceful dimension space, for information transmission in the air. It has been demonstrated that multiple antenna system provides better BER and it can be further improved by using different modulation techniques. Since then, multiple-input multiple-output (MIMO) system has become one of the major focuses in the research community of wireless communications and information theory. The study of the performance limits of MIMO system becomes very important since it gives a lot of insights in understanding and designing the practical MIMO systems. There are many modulation techniques that can be applied to MIMO systems such as BPSK, QPSK, and the Vertical Bell Labs Space-Time Architecture (V-BLAST). In this paper, we study the performance of general MIMO system, the general V-BLAST architecture with Zero-Forcing (ZF), in fading channels. Based on bit error rate, we show the performance of these receiver schemes indicates that the ordered SIC detector ZF with symbol cancellation and optimal ordering to improve the performance with lower complexity and compare the computational complexity of these schemes with other existence model. Finally, the paper addresses the current questions regarding the integration of MIMO system in practical wireless systems and standards.