BER Performance of QAM and QPSK Modulation Technique for DCT Based Channel Estimation of STBC MIMO OFDM

Consumer demand for high speed data communication system is increasing day by day. However the major challenges for wireless communication system are Inter Symbol Interference (ISI) and Inter Carrier Interference (ICI) that occur during data transmission. This interference will distort signal and increase error rate in the system. Combination of Orthogonal Frequency Division Multiplexing (OFDM) and Multiple Input Multiple Output (MIMO) give a reliable high data rate. Discrete Cosine Transform (DCT)-based channel estimation is used in STBC MIMO-OFDM and simulated using MATLAB software. The system performance is compared with multiple antenna configuration and different modulation technique. Multiple antenna configurations that involve during simulation are 2x2, 4x4 and 6x6 while modulation techniques are Quadrature Amplitude Modulation (QAM) and Quadrature Phase Shift Keying (QPSK). This simulation will prove that the higher number of transmit and receive antenna, the lower BER for the system.