Based On The Dmb-th, Forward Error Correction Encoding And Decoding Structure Optimization And Design

Error will occur during the transmission when digital television signal is transmitted in channel interfered by noises and multi-path effect. For dependable transmission of the digital television signal, technology of Front Error Correction has been used in digital television broadcasting system.In this dissertation, based on the standard of DMB-TH (Terrestrial Digital Multimedia TV/Handle Broadcasting), a research about BCH encoding/decoding and LDPC encoding is finished, and has these modules implemented. Firstly the system structure and FEC (Forward Error Correction) coding scheme are introduced. Based on the visible FEC coding scheme, we have the FEC coding structure optimized. In this optimized FEC coding structure, we use parallel BCH coding cascade with PISO (Parrallel Input Serial Output) structured QC-LDPC coding scheme. Then we have the high-speed BCH coding and QC-LDPC coding module designed and implemented. Based on the property of BCH code in DMB-TH standard, a high-speed parrallel decoding algorithm is chosen, designed and implemented.Through verification of simulation, the function and performance fulfilled the DMB-TH standard. The multi-rate LDPC encoder is proposed in this dissertation based on shift-register-parrallel-mutipliy-adder (SRPMA). The SRPMA algorithm simplifies the encoder computation module and reduces the complexity of the operation. The multi-rate encoder reuses the SRPMA circuits to cut down the number of resource consumption. Compared with the channel encoding based on serial BCH encoder and SIPO LDPC encoder, the system constructed by LDPC encoder and BCH encoder that proposed in this dissertation has more resource consumption and more encoding efficiency rised.