Synchronization And Channel Coding Technologies For Digital Satellite Broadcasting Transmission System

In this paper, based on the research of DVB-S/S2 main technologies, we propose an analysis of their synchronization algorithms as well as improvement and design of the structure, still the low density parity check code is instituted here, which is the new hot discussion in channel coding field with digital satellite TV. We introduce the system structure; choose the right symbol timing recovery and carrier recovery for QPSK demodulation; propose several improvements to enhance the acquisition of frequency offset and the adaptivity for low signal power to noise power. Then for implementing the synchronization with the second digital satellite TV system, the APSK constellation feature and frame structure are referred; classified discussion for data-aided and non data-aided carrier recovery algorithms are performed. The author also makes the relevant scheme better to appropriate both PSK and APSK modulations, so our synchronization subsystem gets the ability of acquiring frequency offset in big range, still the better anti-phase-equivocation problem brought by both residual frequency and noise. After that, LDPC coding and decoding are argued, especially its application in DVB-S2 standard. A suitable decoding method to decrease the decoding delay is proposed. All the design is simulated with MATLAB, which shows the good performance of our DVB-S/S2 synchronization sub-system and the requirements of two standards are achieved.