Digital Video Broadcasting Satellite, Second Generation and its extension DVBS2X are widely used in modern satellite communications, where synchronization relies on physical layer headers, pilot symbols, and optional superframe structures but lacks defined implementation methods. This work explores the use of external synchronization to enhance DVBS2 performance by using GPS disciplined oscillators, and a hardware software in the loop satellite channel model emulating Low Earth Orbit propagation. We evaluate scenarios with and without Doppler shifts and radio frequency interference, comparing synchronized and unsynchronized cases. Results show that external synchronization significantly improves bit error rate, frame error rate, and signal-to-noise ratio, subsequently reducing the frames required for reliable synchronization and enabling higher throughput in future satellite communication systems.