Channel Simulation And Synchronization Algorithm Simulation And Study With High-Speed Railway Environment

With the rapid economic and social developments, high-speed railway is playing a more and more important role in the transportation of China. Consequently, the new generation wireless communication networks suitable for high-speed railway has become a significant issue. To study the key technologies of high-speed railway communication systems involving encoding, modulation, synchronization, channel estimation and so on, the modeling of channel statistics related with high-speed railway environment is crucial.In this thesis, on the basis of researches on radio propagation characteristics in high-speed railway geographical environment, the statistical characteristics of radio wave parameters are analyzed and the channel model is built, which is composed of indistinguishable space paths with different delays. Being an improvement of Jake channel simulation model, the proposed channel model is simulated and analyzed in the thesis.As a multicarrier transmission technology, orthogonal-frequency division-multiplexing (OFDM) is applied extensively in wireless communications due to its high data-rate transmission capability and easy channel equalization scheme. However, as a difficult while hot problem, especially in high-speed railway environment, the synchronization is crucial for OFDM system because high-speed mobility may introduce serious Doppler shift and therefore destroy the orthogonality among subcarriers. To overcome the effect on system performance exerted by synchronization error, a data-aided synchronization algorithm is applied to the OFDM system with high mobility to estimate the synchronization shift. Estimating the synchronization and frequency shift jointly through one pilot symbol, the algorithm is shown to exhibit satisfactory effect in high-speed mobile environment by simulation.