Transmission Characteristics of 2x2 MIMO System Using OSTBC Multiplexing for Different Detector Systems

A detail analysis of the performance of 2X2 MIMO (Multiple Input Multiple Output) antenna systems has been carried out for three different types of detectors at the receiver end by determining the transmit diversity using OSTBC multiplexing techniques. The transmission characteristics of the MIMO system have been determined for BPSK, QPSK and 16-QAM modulation schemes presuming Additive White Gaussian Noise (AWGN) and for the flat fading Rayleigh channel. On the receiver side, equalization detection technique are determined by combining Successive Interference Cancellation with Zero Forcing (ZF-SIC), Minimum Mean Square Equalization (MMSE-SIC) and Maximum Likelihood (ML-SIC) has been employed for determining the BER Vs SNR performance of the communication channel. The simulation results show that for BER of ~10 -3 , the SNR increases with higher modulation schemes from BPSK to 16-QAM. Further the results of the analysis for different detector systems indicate that for BPSK modulation at BER ~10 -3 , the SNR values are found to be ~24.46 dB for ZF-SIC, SNR ~20.6 dB for MMSESIC and SNR ~14.46 dB for ML-SIC detectors. Thus the BER performance of 2X2 MIMO-OSTBC transmission channel shows the reduction of SNR ~10 dB for ML detectors. A comparison of the MIMO performance with OSTBC multiplexing techniques indicate that the 2x2 MIMO–OSTBC transmission channel for BPSK modulation depicts better performance for OSTBC multiplexing with ML detector system at the receiving end. The simulations results are presented and discussed in the paper.