Research On Detection And Adaptive Transmission Technology In Broadband Satellite Mobile Communication System

Satellite mobile communication system has flexible networking,wide coverage and other characteristics.Due to the limited power of satellite device,large channel transmission delay,special fading model and the channel differences compared with ground communication system,it can't use the ground LTE communication technology directly.Research on satellite mobile communication system which is compatible with LTE mobile communication system has a great significance.This thesis focuses on the design and implementation of detection and adaptive transmission technology in the broadband satellite mobile communication system.First,the design of the uplink wireless transmission signal in the broadband satellite mobile communication system and the modeling of the broadband satellite channel are investigated.The frame structure and slot structure of the transmission signal and the configuration of physical resource suitable for broadband wireless transmission are designed.According to the characteristics of satellite communication,a MIMO broadband satellite channel model is built.Meanwhile' the generating of physical uplink channel is discussed.Then,a group whiten filtering based detection with soft-demodulation is investigated.This detector divides all users,subcarrier symbols into several groups in DFT-S-OFDM system,and each group has two or three symbols.When detecting a certain group of symbols,the others are treated as interference,which are whitened together with noise.The simulation results indicate that the proposed detector can achieve a good compromise between complexity and performance compared with MMSE iterative receiver.Subsequently,adaptive transmission method is investigated for S-LTE uplink.Based on the satellite communication adaptive transmission model,the procedure of reporting rank indication(RI),pre-coding matrix indicator(PMI)and channel quality indicator(CQI)is discussed,and calculation methods of three feedback parameters are derived.Besides,the performances of MIESM and EESM are compared,which are popular effective SNR mapping models in adaptive modulation and coding.Moreover,the CWER and spectral efficiency under different antenna number and antenna correlation are given and analyzed.Finally,the design and implementation of the group whiten filtering based detection with soft-demodulation and adaptive transmission method are investigated.The system signal processing and scheduling are designed based on the characteristic of the hardware platform.The statistical analysis is performed to quantify the signals of each module,and the performance of fixed-point implementation is confirmed through simulation results.Then,detailed hardware design of each module is proposed.A large number of test cases in various scenarios are analyzed and tested to verify the correctness and robustness of the system.