PAPR reduction in MIMO-OFDM system using combination of OSTBC Encoder and Spreading code sequence

Orthogonal Frequency Division Multiplexing (OFDM) is regarded as one of the most outstanding multicarrier modulation technique in fourth generation (4G) wireless networks, which makes it possible to transfer very high bit rates despite extensive multipath radio propagation (echoes). The use of smart antenna arrays both at transmitter and receiver further increases the bit rate and enhance the system diversity on time variant and frequency selective channels resulting in a multiple-input multiple-output (MIMO) configuration. However one of the main disadvantages associated with MIMO-OFDM is the high Peak-to-Average Power Ratio (PAPR) of the transmitter´s output signal on different antennas. High Peak to Average Power Ratio (PAPR) for MIMO-OFDM system is still a demanding area and difficult issue. So far numerous techniques based on PAPR reduction have been proposed. In this paper a new method based on the combination of OSTBC Encoder and Spreading code sequence have been implemented and simulated. The results obtained are compared with earlier results based on transform techniques. Simulations show that better results are obtained in proposed technique.