Rapidly Varying Selected Channel Burst Efficient Transmission Method Design Study

OFDM is one of the important wireless communication technologies. Based on the XX preresearch project, this paper researches the transmission of OFDM system on the rapid time-varying double selection channel from many aspects. It is got the system transmission architecture adopted this project. Comparative analysis and selection are involved about transmission for fast-varying channel. And burst frame structure design and corresponding algorithms are deduced in the paper.In detail, main work is expressed as following:(1) It is demonstrated that the OFDM modulation is the best method for fast transmission on the rapid time-varying double selection channel from theoretical analysis and simulation analysis. For CE-OFDM, SC-FDE, CPM-OFDM, their advantages and limitations are given from the aspects such as the shaping of signal waveform, the power efficiency of transmitter, the system transmission spectrum efficiency and the system implementation costs. Through comprehensive process and compromise consider, OFDM transmission is selected in the project at last.(2) The system based on OFDM is comprehensively designed. According to the requirements of the project, it selects the system with single antenna at the transmittor and multi-antenna at the receiver. The key technology and design point about the whole system are shown and so is the block diagram of system implementation design.(3) For one of the key technologies about the system on the time-varying double selection channel, the design of burst frame is focused on. Firstly, there are some improvements on 802.11a standard, which help adapt to the fast-changing wireless environment. The simulation results show the standard and the improved standard both don't meet the requirements of the project. Then based on the requirements of the project purpose and the features of fast-varying channel, the structure of burst frame is designed. The emphasis is design of preambles, signaling domain and pilot OFDM symbol through which the corresponding frame format adapted to the project is got. And based on the format, the frame and carrier synchronization algorithms are deduced. The affectivity of these algorithms is proved. At last the system-level simulation further gives the proof that the system design and the frame design are efficacious.