Launch Wireless Image Transmission System Design And Implementation

Wireless video transmission is widely used in civil and military fields by the advantages of real-time, wireless and visualized. The arm of this dissertation is architected a wireless video transmission system. Research of launch systems is very important as key component of terrestrial digital TV system.According to the project, terrestrial digital TV broadcast frame based on DTMB is used in this dissertation, and MPEG-2is coded in the source coder. The simplified DTMB digital terrestrial television standard is adopted for channel. Considering small size, wide temperature range, low power consumption, and integrated technologies to degree of difficulty, this system completes device selection and the design of hardware and software. The main work of this dissertation as follows:1) Accrording to the project requirements, the solution design of the system is completed in this dissertation, include core chip selection, module partition, and design of source and channel encoding board.2) In this dissertation, the TMS320DM642, which belongs to the TI’s DaVinci series DSP, has been used as core decive of the information source encoding and decoding. The software design includes video capture task, MPEG-2encoding task, TS stream packaged task, and output of TS stream task. The tasks are verified in the end.3) Based on the codec principles, the simulation and FPGA implementation of DTMB channel coding is completed. The0.4coding efficiency of forward error correction coding and convolutional interleaving of symbol are designed. The baseband processing, including channel coding, modulation, weaving, and filtering, is implemented under a single carrier and non-pilot conditions. It implments the DUC and DAC by the control of AD9857and outputs different signal to RF module.4) This dissertation completes schematic design and PCB design of source and channel. It mainly studies video capture, design of self-starting of FLASH-based TMS320DM642program, design of power module and intermediate frequency DAC module. Moreover, the source and channel circuit board is debugged.Above all, the schematic diagram design is completed in Altium Designer, and PCB design is completed in Cadence Allegro. Source program is designed in the CCS3.3, which is an integrated development environment in TI, and is verified on the circuit board; Channel model was simulated in MATLAB and implemented in the FPGA device EP3C55F484I6. Finally, step-by-step test to the system is accomplish and the result indicates that the features in the source and channel, and reached the expected requirements.