Research Of On-Board Sample Switching Technique Based On Flexible Transponder

On-board processing and switching is one of the key techniques in broadband satellite communications systems. Owing to the limited resources of the satellite platforms, broadband satellite communication is facing with two major challenges, one is the difficulty of achieving on-board signal processing and switching for large-scale users, the other one is the ability to support all-IP broadband Internet services. On-board switching technique based on flexible transponder can solve this problem effectively. Therefore, in this thesis, based on the analysis of broadband flexible transponder, on-board high-speed sample switching technique which combines the circuit switching with the IP switching is demonstrated primarily. Moreover, a multiplexing time-slot circuit-switched network is also proposed. Finally, FPGA design and implementation of this switching network are provided in this thesis. The main contents of this thesis are as follows:1. A novel on-board switching modes which combines the IP switching and circuit switching is demonstrated, and its realization structure is provided. Furthermore, the superiorities of this exchanging mode are also analyzed in terms of the Qo S, network delay, network data throughput, hardware implementation complexity and so on.2. Two types of on-board exchanging networks are studied: T-S-T switching network and multiplexing time-slot circuit-switched network. And that their composition structure and fundamental principles are analyzed emphatically. Through comparative analysises of the complexity, the resource utilization ratio and the number of the port connection lines of both switching networks, the multiplexing time-slot circuit-switched network is selected ultimately as the on-board switching solution.3. For the on-board switched network, a network signaling transmission solution is given. By inquiring the routing table, any signal switching function is implemented among the four ports containing 192 sub-channel signal sunder the switching clock of 125 MHz.4. FPGA design and implementation of the on-board multiplexing time slot circuit switched network is completed. With the principle of modularization design, the whole on-board switching system is modularized firstly. Then, the FPGA design andimplementation of each sub-module is carried out separately in this switching network. Finally, the functional simulation and analysis of this whole on-board switching network are also presented.