Turbo-coded OFDM with a novel synchronization technique for broadband wireless applications

In this thesis, an orthogonal frequency division multiplexing (OFDM) system, featuring a novel bandwidth efficient synchronization technique robust to multipath propagation, is presented and analyzed. The timing offset and frequency errors due to the transmission over a wireless multipath fading channel can result in rapid bit error rate degradation in OFDM systems. The idea of the proposed simple and efficient synchronization technique is to reduce this degradation by designing a synchronizer with a smaller error variance and also less overhead. This enables us to strengthen the robustness of OFDM to severe multipath propagations by successfully removing the cyclic prefix (Inter Symbol Interference free) and maintaining the orthogonality between all the subcarriers (Inter Channel Interference free). Furthermore, the thesis focuses on the application of diverse channel coding for the coded orthogonal frequency division multiplexing (COFDM). The performances of the COMM based on Turbo Convolutional code (TCC) and Turbo Block code (TBC) are analyzed and compared. This work also includes channel estimation, which is very important for coherent demodulation in OFDM. (Abstract shortened by UMI.)...