Paper Title
Performance Analysis Of SFBC (MIMO) OFDM System In Fast Fading Channel

In a 4G OFDM system the channel needs to be constant during transmission of one orthogonal design. The elements of the orthogonal design can be distributed as space-time block code over successive OFDM symbols which might cause problems in fast fading channels. To avoid the problem of fast channel variations in time, the symbols of an orthogonal design can be transmitted on neighbouring subcarriers of the same Orthogonal Frequency Division Multiplexing (OFDM) symbol rather than on the same subcarrier of the subsequent OFDM symbols. This also reduces the transmission delay. Space-Frequency Block Codes (SFBC) avoids the problem of fast time variations. SFBC with maximum likelihood detector is introduced and examined for flat and frequency-selective channels over various values of Doppler frequencies and various type of modulation (QPSK, 8-PSK, 16-QAM and 32-QAM). The accuracy and effectiveness of the theoretical analysis is verified by the results with idealized multipath channel models as well as the ITU pedestrian and vehicular channel models.