Research On S-band Channel Modeling And Implementation Technology Under Satellite LTE System

As a vital component of mobile communication, communication via satellites maintains user mobility and global coverage with no blind zone, especially in regions where terrestrial network coverage is costly or even impossible. It is irreplaceable under emergency circumstances such as during a natural disaster or wartime. With the recent countrywide issuance of LTE 4G license, the time for high bandwidth mobile internet has come. As one of the key technologies for LTE, OFDM is resistant to frequency selective fading, and has high frequency utilize. With satellite communication being an important complement for terrestrial mobile communication, researches on combining satellite communication with LTE for mobile internet have become prevalent. Satellite mobile channel is the physical medium for signal transmission, and its impact on the performance of satellite communication cannot be ignored. Satellite communication under S-band requires more accurate modeling of the satellite mobile channels. It is therefore crucial to study channel modeling for satellite communication under S-band, to discuss OFDM signal transmission performance of LTE system under S-band and to subsequently develop channel simulator.The following studies are presented in this work:1. We analyzed the spatial, temporal and frequency dependencies of satellite mobile channel under S-band. Based on existing models for satellite channels and simulations, we improved Loo model using semi-Markov chain method and detailed simulation process.2. We studied the Monte Carlo method for random number generation, and simulated inverse transform technique and accept-reject algorithm. We briefly introduced Markov chain and its property, detailed the principles for MCMC method, and presented frequently-used MH algorithm. We use MH algorithm for random number generation in satellite channel modeling and compared with the Matlab built-in algorithm.3. We analyzed the resistance to frequency selective fading and the realizability of low-complexity channel equalizing of OFDM technology. Besides, we analyzed and simulated the transmission performance of LTE-OFDM system under typical wideband satellite frequency-selective channel. We analyzed the transmission performance of LTEOFDM system under different satellite channel environment and elevation angles by simulating LTE-OFDM transmission based on two state semi-state Markov chain satellite channel model.4. We improved the satellite channel simulator from the same group by incorporating the satellite channel model under S-band and random number generator based on MCMC method discussed previously in this work. We presented the schemes for both software and hardware implementation.