Research On The Key Techniques For Mobile Satellite Communications System Based On MF-CDMA/CWTDM

This thesis researches on a new satellite communication system based on onboard MF-CDMA/CWTDM conversion. This system can greatly reduce transmitting EIRP and also reduce G/T of the receivers. It still significantly enhances the capability of the downlink signal anti-intercepted and anti-jamming. Whether in civil mobile satellite communications or military satellite mobile communication systems, it will have important significance.The thesis mainly deals with that CWTDM combined with de-spreaded onboard. The main contents and results:1. Completed design of the satellite communication system based on onboard MF-CDMA/CWTDM conversion, and analyzed detailedly the theory and some key techniques of the transmitter, included de-spread onboard, CWTDM multiplexer/ de-multiplexer technique, frame technique, offset estimation, synchronization technique onboard and receiver.2. Analyzed detailedly the onboard part integral de-spread technique, the synchronization accuracy's effort and the simulation verification. In this paper, it presents a new downlink synchronization program and gives theoretical analysis and simulation verification.3. Completed MF-CDMA/CWTDM system simulation by using SystemView, it analyzes performance and constructs modules of the key techniques, including part integral de-spread, CWTDM multiplexer/de-multiplexer, offset estimation, synchronization acquisition. Through system simulation the bit error rate can be showed.