Synchronous and the coherent phase-locked synchronous oscillators: new techniques in synchronization and tracking

The synchronous oscillator (SO) and the coherent phase-locked synchronous oscillator (CPSD) are described. The SO is a network that synchronizes, tracks, filters, amplifies, and divides (if necessary) in a single process. It has excellent noise rejection properties while maintaining a wide tracking range and fast acquisition times. Frequency acquisition occurs in a few cycles followed by phase acquisition. The CPSO is created by adding two external loops to the SO. The CPSO retains all the virtues of a SO while providing coherency throughout the tracking range. In a CPSO the tracking range is fully independent of its noise bandwidth. The SO has been used in various synchronization and tracking. spread-spectrum, and optimal receiving systems. In addition, the SO has been used in high-speed, burst-mode modems as a clock and carrier recovery network. The CPSO is used whenever the input SNR is low and the tracking range requirement is wide