The Research And Realization Of The Key Technologies Of DSP-based OFDM Reciver

Orthogonal-frequency-division-multiplexing (OFDM) technology is a new modulation technology. It is suitable to high-data-rate transmission in the wireless transfer channel with muti-path transmission, which has become an attractive technology nowadays.OFDM technology is multi-carrier technology, high spectrum efficiency, and is expected to be used in the fourth generation mobile communication system. But now the application of OFDM technology is not so close to our lives, what's more, there are many defects in the application. There are many difficulties in the integration of related technologies and OFDM technology and we are also lack of practice experiences and useful results. Therefore, at the beginning of my research, deciding to do best to practice in engineering based on OFDM theories and also to sum up the experiences of the technology. After comprehensively verifing the feasibility, effectiveness, availability of the theory using an engineering method, and try to propose a scheme of how to use this technology based on OFDM theory. Wish this can make a little contribution to promoting the development of OFDM technology.The research method of this thesis is to apply and verify theory in practice. The paper focus on researching the basic theory of OFDM, especially, the key technology of OFDM receiver, and comprehensive refer to the existing wireless communication network protocol specification, to establish the parameters and algorithm to this design according to the application environment and hardware characteristics, than through optimizing the simulation to verify basis theory. Finally, a OFDM receiver platform has been built based on DSP assessment platform for debugging the DSP software modules, give a further demonstrate to the key technologies of OFDM receivers.Firstly, the paper provides a detailed analysis of the basic principles of OFDM receiver and its key technologies. The whole scheme of receiver has been simulated by Matlab platform, which deepens the knowledge to each module of the OFDM, to guide the establishment of hardware platform and the preparation of DSP software; Referring to existing wireless network standard, to formulate the parameters and scheme of system to the present application environment and hardware features. A DSP/ BIOS-based development system has been built, which is based on the digital evaluation board TMS320C6416DSK of TI. Finally, the software algorithm including the removal of cyclic prefix, the FFT algorithm of Radix₄ and the 16QAM modulation for OFDM receiver using the scheme has achieved. The design fully uses the hardware, you can not only have a better understanding of the working process of OFDM receivers to verify the theoretical basis, but also further understand the key technologies.