Simulation And Implementation Of Interleave In Digital Terrestrial Television Broadcasting (DTTB) Transmission System

With the growing needs of people for digital television and digital video information, digital television broadcasting is developing rapidly in China. In recent years, the digital television transmission system technology matures gradually and Digital Terrestrial Television Broadcasting (DTTB) transmission standards formally tabled on August 30, 2006 too. This is the standard technology made by several units from their joint research, with independent intellectual property rights. The study and simulation for DTTB systems are of tremendous practical value and broad market prospects.The condition of digital terrestrial TV broadcasting transmission is the worst compared to the cable channels and satellite channel. In DTTB systems, in order to guarantee the transmission quality of system information, practical data-interleave technology is used to resist the interference by unexpected errors in addition to the use of channel coding to reduce the error rate. Adding interleaver in the transmission end and deinterleaver in the receiving end make the unexpected errors of the channel disperse and the unexpected errors channel transform into independent random errors channel, which can give full play to the role of error-correcting codes. With interleave, the system can improve the performance of several orders of magnitude.In DTTB national standards, the use of interleave technology has two main components: time-domain symbols interleave and frequency-domain interleave. Time-domain symbols interleave use convolution interleave coding while frequency-domain reorganize the order of uninterleaved data through the insertion and cycle calculation method to achieve the purpose of interleave. Time domain symbols and frequency domain interleave, these two aspects are interlinked, located between channel coding and OFDM modulation, and has played the role as nexus in the system.This paper firstly analyzes the role and principle structure for interleave technology of DTTB system, and then design the time-domain symbols interleave and frequency-domain interleave and realize them by hardware, in accordance with DTTB standards technical requirements. With the deeply understanding of algorithm principle for the convolution interleave and the frequency domain interleave, the realization scheme of the interleave and deinterleave for these two parts is demonstrated in this paper, which use Altera's Stratix II series EP2S90F1020C5 chip hardware implementation.Time domain convolution interleave adopt the whole block RAM cycle addressing algorithm. The algorithm is simple and effective, speedy, and occupies little hardware resources space and improves the performance of convolution interleave. The SDRAM controller designed myself can cope with the shift of the data cache process effectively. Frequency domain interleave adopts a look-up table method to achieve reorganization of order for the data by calling the RAM and ROM to achieve quickly addressable. In this paper, the design realizes simple, works stability, and achieves a pre-determined experiment objective.