The Research Of Software Radio Theory And The Design Of IF Software Radio Receiver Sub-system

SR(Software Radio) is a new radio communication implement idea that was brought forward years before. It's also the future radio communication development trend. SR is just a general-purpose hardware platform which combining with modularization and standardization hardware units by the way of bus. The key thinking of the SR are making ADC and DAC as near as possible to the antenna, and realizing as many radio functions as possible by loading software module. The main characters of SR are its software flexibility and structure opening. SR technology has been the key technology of the 3rd generation mobile communication system.The purpose of this thesis is to work deeply over the SR theory, understand the key thinking of SR, cognize the key technologies of SR, and design the IF(intermediate frequency) SR receiver subsystem basing on the SR theory. The research method of this thesis is theory guiding practice, and practice validating theory. Namely, using the SR base theory to guide the design of the IF SR receiver subsystem and loading the software program to realize the hardware module function, which commendably reveals the SR thinking.This thesis firstly introduces SR base theory, which primarily including signal sampling theory, multi-speed signal processing theory, high-efficiency digital filter theory, signal's quadrant transform theory, then constitutes the SR receiver mathematic model. Secondly, basing on single channel IF SR receiver mathematic model, thisthesis has designed IF SR receiver subsystem and brought forward its design project and system circuit principle diagram, and explained the system working principle. Furthermore, this thesis introduces the working principles and respective applications of wideband high-speed ADC AD6640, DDC AD6620 and high-speed DSP TMS320C6713 according with the IF SR receiver subsystem high-speed analog digital conversion department, digital down conversion department and high speed digital signal processing department. Thirdly, the thesis emphatically demonstrates the software realization department of the IF SR receiver subsystem, which including AD6620's inner parameter software setup, TMS320C6713 data transmission and processing and the quadrant demodulation algorithm program realization. Finally, basing on the IF SR receiver subsystem hardware platform, by AD6620 programming on the line and TMS320C6713 loading the digital signal quadrant demodulation program, the thesis having realized the demodulation of the AM signal, which validates the key thinking of software radio.