Abstract:Software Defined Radio (SDR) has become a hotspot research of mobile communication because of its flexibility and versatility. However, the mainstream SDR prototype platform only realizes point-to-point communication. Because it fails to solve the problem of clock synchronization, it is difficult to ensure timing control and multi-user scheduling in the aspect of multi-point communication. In order to build a multi-point communication scenario based on SDR platform, a software network synchronization mechanism is proposed, and round-trip delay is used, RTD) algorithm obtains the soft clock synchronization. The experiments show that the soft clock source with nanosecond error can be obtained on the Microsoft software radio prototype platform (Sora), which can simulate the multi-user communication scenario under TDMA access mode. In conclusion, the experiments verify the correctness and stability of the soft clock synchronization mechanism.