Design And Implementation Of Baseband Signal Processor For Wireless COFDM Transmitter

The wireless COFDM video transmission technology is widely used in the fields of forest video,terrain measurement,aerial mapping,emergency rescue and other wireless video transmission because of its high transmission rate,high spectrum utilization and strong anti-interference ability.Therefore,the application of COFDM technology in the field of wireless video transmission is still a research hotspot.This project designs and implements a baseband signal processor for wireless video transmission systems based on COFDM technology,which can be widely applied to platforms such as UAV image transmission systems and wireless video surveillance systems.In this paper,Xilinx Spartan-6 series XC6SLX45CSG324 chip is selected.According to the DVB-T technology standard,the code modulation function of COFDM baseband processor is designed by FPGA for DSP device to realize the baseband processing function of COFDM transmission system.The main research contents are:The design of the channel coding of the baseband signal processor of the wireless COFDM transmitter is completed.The channel coding includes energy diffusion,RS coding,convolutional interleaving,convolutional coding,bit interleaving and symbol interleaving.Based on the detailed analysis of the principle of each module,the FPGA implementation scheme is given.According to the designed FPGA scheme,the Verilog code of each module is written,and the timing simulation is verified after the compilation.After the verification,the code is downloaded to the FPGA development board,and the internal signal of each module FPGA is observed by Chipscope to verify the feasibility of the hardware implementation.The design of the channel modulation of the baseband signal processor of the wireless COFDM transmitter is completed.The channel modulation includes constellation mapping,frame formation,OFDM modulation,and guard interval.Based on the detailed analysis of the principle of each module,the FPGA design scheme is given.According to the designed FPGA scheme,the Verilog code of each module is written,and the timing simulation is verified after the compilation.After the verification,the code is downloaded to the FPGA development board,and the internal signal of each module FPGA is observed by Chipscope to verify the feasibility of the hardware implementation.Finally,write the top-level design code to cascade the modules into a whole.After the overall timing simulation is verified,download the code to the FPGA development board for board-level verification.The verification results show that the COFDM transmitter baseband signal processor scheme is feasible,the design is correct,the function is effective,and it has the advantage of occupying less resources,which can provide useful technical reference for related engineering design.