Optimization of MIMO- FFT based OFDM system performance with minimum BER

Alomouti’s space-time coding scheme for Multi-Input Multi-Output (MIMO) system has drawn much attention in 4G wireless technologies. Orthogonal frequency division multiplexing (OFDM) is a popular method for high data rate wireless transmission. OFDM may be combined with antenna arrays at the transmitter and receiver to increase the diversity gain and enhance the system capacity on time variant and frequency selective channels, resulting in Multi-Input Multi-Output (MIMO) configuration. This paper explores varies physical layer research challenges in MIMO-OFDM system design including channel modeling, space time block code techniques, channel estimation and signal processing algorithms used for performing time and frequency synchronization in MIMO-OFDM system. The existing FFT based OFDM in MIMO the BER is more compare to wavelet based OFDM. But the wavelet based OFDM have more computational and hardware complexity in this paper we proposed mixed radix FFT algorithm with constant multiplier multipath delay feedback scheme. The performance MMO-OFDM is optimized with minimum BER.