FPGA-Based Hardware-in-the-Loop Simulation of User Selection Algorithms for Cooperative Transmission Technology Over LOS Channel on Geosynchronous Satellites

Distributed satellite clusters and cooperative transmission technology have been used to improve the communication capability of the geosynchronous orbit (GEO) satellites in recent years. To validate the effectiveness of distributed cooperative technology, the authors designed an information transmission system using FPGA-based hardware-in-the-loop simulation. The focus of this paper is to complete the implementation of the link layer user selection algorithm to verify that cooperative transmission techniques are feasible. This system uses a Xilinx ML605 FPGA for simulating the synchronization and exchange of data during coordinated transmission in a GEO window. The authors assumed a dual-satellite scenario in the simulation used to validate the efficacy of the satellite system. After testing the system optimized with pipelining technology, the number of clock cycles was reduced by 66%. Furthermore, tests showed the system can process multi-user channel data with signal-to-noise ratios ranging from 110dB to 195dB and could select the optimal channel. Additionally, in a case study with 10 users and 2 collocated satellites, this optimized system’s operation speed is approximately 2000 times faster-after hardware acceleration-than general-purpose processors, which verifies the efficacy of using distributed cooperative transmission algorithms. Because of this, the low-cost, and the low-power features, this system is a promising candidate for an embedded real-time simulation platform for GEO satellites.