The Digital Implementation Of Intermediate Frequency Modulation And Demodulation System

The multi-frequency, multi-velocity, multi-modulation intermediate frequency transmitting system was achieved on the platform of DSP+FPGA based on the theory of Software Radio in the dissertation.The dissertation introduced the principium and development of the theory of Software Radio, followed with the principium and implement of Multiple Modulation and Demodulation, convolution coding and Viterbi decoding in DSP. Then discussed in detail the design and implementation of Digital Up Conversion and Digital Down Conversion; Based on the project objectives, the system scheme was presented, which not only dealt with constructions of both software and hardware, but also defined data-transmitting format and transmission interfaces between DSP and FPGA. In the end, all the modules were integrated in a main body called Intermediate Frequency Modem, and the testing results were provided...