Research And Implementation On Symbol Timing Recovery Algorithm Of DTTB System

This paper makes a deep research on the symbol timing synchronization algorithm in Chinese Television Terrestrial Transmission system. First of all, makes a deep research on the traditional structure of Symbol Timing Recovery by interpolation. The emphasis is focused on the introduced of the principles and realization method of the interpolator, also the algorithm for detection of timing error is analyzed from time domain and frequency domain. Then, because of the specific frame structure of the TDS-OFDM system, a novel code acquisition and symbol timing recovery method is adopted. A new algorithm of down sample combined with Number Control Oscillation (NCO) is proposed, and an improved algorithm is proposed which performs well under the multi-path channel. The difference of positive sampling frequency offset and negative sampling frequency offset is analysed, and an improved structure of the system is presented. Simulation results show that the algorithms provide better synchronization performance under frequency selective and time selective fading channels. Finally, taking the practical physical layer transmission control mechanisms into account, a total solution is proposed to the whole architecture for timing recovery system in DTTB system demodulator, which is tested and verified by demodulating data acquired in field test. The test results show that the proposed architecture and control mechanisms are reasonable and low complex.