Combined Space-time-frequency codes for four time slots with beamforming

Multiple-input multiple-output orthogonal frequency-division multiplexing (MIMO-OFDM) system has been implemented to achieve a good service and boost the data rate in wireless communication system. Space Time Frequency (STF) is used to enhance the diversity gain. This paper aims at a performance analysis of MIMO-OFDM system using two different STF codes with a random beamforming. The two proposed codes give better bit error rates (BER) performance as compared to the BER performance of STF of Alamouti code for MIMO-OFDM system. We have applied STF with random beamforming to improve the performance of the whole system for different diversity. The performance of the second STFC is better than the performance of the first STFC at high signal to noise ratio (SNR). It is also observed that the BER performance of the two proposed schemes with beamforming is better than the BER performance of space-time block codes (STBC) with beamforming.