Guest Editorial: Special issue on synchronization

Synchronization is a fundamental problem in digital cornmunications systems. In radar, sonar, and navigation systems, synchronization is connected with the objectives of measuring range, velocity, and position. This Special Issue is devoted specifically to the synchronization problem as it relates to digital communications engineering and technology. In the implementation of digital communication systems, one must distinguish among several types of synchronization. Some of these are: 1 ) carrier synchronization, 2) clock synchronization. 3) codeword and node synchronization, 4) frame synchronization, and 5) network synchronization. This Special Issue provides papers which address each of the above synchronization types. Additionally, special problems related to the operation and performance of synchronizers which employ the phase-lock principle are provided. A brief overview of the content of this Special Issue is presented.