Transmitter Baseband Design Based On OFDM Wireless Transmission

With the development of society,people have raised higher requirements for UAV's application.It is popular to shoot pictures at high altitude with UAV,store them and send them back to ground.In order to lighten the load of the UAV,researching on the integrated design by image collection,preprocessing,source coding,modulation and other signal processing module becomes a tread.In this dissertation,the COFDM with high spectral efficiency and strong anti-interference ability is used to complete the design of modulation module of the image transmission system.Based on the completion of transmitter systematic simulation,the following work is done.1.The dissertation describes the wireless channel fading,analyzes the basic principles of OFDM/COFDM technology and sets OFDM symbol parameters and frame structure of the system according to wireless application environment and refer to other wireless network standards.2.The dissertation accomplishes the hardware implement of the OFDM-based baseband transmitter algorithm.The correctness of each unit module is verified by simulation and comparison on Matlab and FPGA.3.The dissertation improves the method of hardware implement of block interleaving module by alternate reading and writing in row and column of square-based.Compared with“ping-pong”operation,this method saves 14%system resources in the same data processing capability.4.The dissertation verifies the feasibility of baseband transmitter system.The dissertation verifies the stability of baseband transmitter system by analyzing the spectrum of the simulation output signal firstly,then verifies waveform implementation performance by simulating receiver in Matlab.When BER is?10^-6,the system EbN0 is close to the standard QPSK.Synthesize two-part results verify that the transmitter system meets the design index.