Research On Key Technology In Mobile Wireless Communications

This paper makes a research on the implementation of high speed FFT and the key technology of Doppler diversity for OFDM system in mobile wireless communication.First, the development of mobile communication technology is introduced briefly, followed by the summarization of the basic idea and the characteristics of MIMO-OFDM technology, and then the Doppler effects and the Doppler diversity which influence the performance of mobile communication technology are analyzed; Then considering the difficulties to keep the balance between speed and resource in traditional FFT technology, a new FFT method of high speed and multimode based on pipeline structure in TD-LTE system is proposed, and the simulation results show that the proposed algorithm has overcomed the unsteadiness in high speed operation. Finally, Doppler spread will become obvious with the increased mobility, frequency offset destroys the orthogonality between OFDM sub-carriers, however, which will bring available resource. Based on this characteristic, transmitter Doppler diversity and receiver Doppler diversity are researched quantificationally for the feasibility. An improved novel simplified receiver Doppler diversity for OFDM system is proposed. After simulation, the optimal configuration of the simplified receiver Doppler diversity is put forward.