Research Of OFDM Based And Signal Processing System And Implementation Of Fixed-Point DSP

With the rapid advancement of electronic and communication technology, the Orthogonal Frequency Division Multiplexing (OFDM) and related subjects such as codec/decodec, modulation/demodulation, have been deeply developed. At the same time, baseband signal processing system based on OFDM is widely accepted and used in various areas, especially in digital video industry.According to terrestrial Digital Video Broadcasting (DVB-T) standard, this thesis researches the OFDM construction, principle and implementation methods, and then builds a set of OFDM baseband signal processing system on TI TMS320C6416T based DSK6416 development board by using fixed-point algorithm. In the implementation, the design combines module requirement of inner codec/decodec, outer codec/decodec, inner interleave/deinterleave, outer interleave/deinterleave with the feature of fixed-point DSP, optimizes the store mode and processing procedure to improve execute efficiency of the code. By comparison, analysis and experiments, the dissertation has tried a new "data combination improved algorithm" to complete IFFT/FFT transformation, which enhances system performance and offers a new approach of integrated data computing operation. Besides, in the interface of baseband system, the transmitting is operated by using EDMA to control McBSP, through interrupt flag and Ping-Pong buffers, the design eases CPU load and assures high-speed, continuous and trustworthy data transmitting.In the system design process, the thesis has tried to improve the implementation method of DVB-T standard on TI C6000 series fixed-point DSP, and it also provides a reference design of using fixed-point algorithm to better implement digital signal processing technology.