Study On Performance Of Nostbc-ofdm System

With the development of wireless communication technology, the requirements of people for the data transmission rates and reliability of wireless communication systems are increasing, but the spectral resource is limited. Therefore, how to improve spectral efficiency, increase the capacity and improve reliability of wireless communication systems have been challenges and opportunities in designing the future wireless communication systems.In this thesis, the performance and combination method of NOSTBC-OFDM system are studied. First of all, the combination scheme is confirmed and configuration block diagram is proposed. Then the performance of the NOSTBC-OFDM system which has two transmit and two receive antennas over frequency selective fading channel is simulated. The simulation results demonstrate that the performances of NOSTBC-OFDM systems are better than that of single OFDM systems, and the fading multi-path effect is changed into a beneficial factor for improving reliability of systems by the NOSTBC-OFDM systems. The coding and decoding algorithm of NOSTBC are also simulated and studied in the thesis. The simulation results demonstrate that the performance of NPSTBC which can achieve full diversity is the best under the high data transmission rates situation. And no matter it is considered from the bit error rate or the complexity of operation, the sphere decoding algorithm is the optimun choice for NOSTBC systems.According to the simulation results, we can get the final conclusion that it is beneficial to use NOSTBC-OFDM systems for high data transmission rates over frequency selective fading channel. In order to achieve the optimun performance of system, the NPSTBC which can achieve full diversity is applied to the transmitter and sphere decoding algorithm is applied to the receiver.