In this thesis work, we obtain the performance of digital audio broadcasting (DAB) system in the presence of carrier offset over multipath fading channels. Then we implement the orthogonal frequency division multiplexing (OFDM) system on the S-RTP station which is a specially designed multi-DSP (TMS320C40) based real time signal processing system.
In general, OFDM is an effective transmission technique for coping with the typical channel impairments present in mobile communication. Since residual carrier frequency error and frame offset of the OFDM system degrade the overall system performance, exact synchronization is very important to obtain the better system performance. To overcome the performance degradation under mobile channel environment, DAB system transmits information with RCPC (Rate Compatible Punctured Code) channel coding and time and frequency interleaving.
To maintain the correct timing of a frame and compensate for residual frequency carrier error, we employ energy and correlation peak detection for frame synchronization and guard interval based frequency detection(GIB FD) for carrier frequency synchronization. With these synchronization algorithms, we analyze the synchronization performance of DAB system over multipath fading channels. Then we implement the synchronization algorithm of OFDM system using multi-DSPs on S-RTP station and verify the synchronization algorithm via transferring data in the presence of carrier offset.
