| dc.description.abstract | OFDM technique is adopted in many standards, including DVB-T, since it exhibits outstanding characteristics in terms of efficiency in spectral utilization, simplicity in equalization and immunity in Inter-Symbol-Interference (ISI). However OFDM system performance is sensitive to synchronization errors including symbol timing offset, carrier frequency offset and sampling clock frequency offset. Typical methods exploiting the correlation of cyclic-prefix in time domain and the correlation of continual pilots in frequency domain have been proposed for estimating and correcting the synchronization errors for OFDM systems. In these methods the channel model is generally assumed to be static, i.e., the transmitter and receiver are in stationary positions and the channel impulse response is time invariant. This assumption is violated especially when the receiver and/or transmitter are in high-mobility environment, i.e., the channel impulse response becomes time varying significantly.
In this thesis, we focus on studying on the synchronization problems of DVB-T system when the receiver is in mobility as high as to 300 km/hr. In this scenario, significant time-varying channel impulse response due to large Doppler spread is noticed which causes the loss of subcarrier orthogonality and signal correlation, and the performance of typical synchronization algorithms is evaluated. Finally, a synchronization method, which is more suitable to high-mobility reception, is designed for DVB-T receiver. The implementation of synchronization systems is verified with Modelsim tool and real-time implementation on FPGA hardware. | en_US |