A generalized frequency correction technique for multiple access satellite communication networks

Abstract

The frequency correction mechanism used within each earth terminal will typically control both transmit and tuned receiver frequencies, the latter being the center of the frequency window over which a receiving terminal searches for a signal. This frequency correction is sometimes referred to as frequency tracking because the controlled corrections are updated periodically to track changes in the contributing sources of these offsets. The technique presented generalizes one previously studied by Chandler (see IEEE Tactical Communications Conference (TCC-90) Proceedings, p.369-379, April 1990). It can be applied to time division multiple access (TDMA) networks where the measured receive frequencies of specific burst signals are used to adjust both the transmitter frequency and the tuned receiver frequency for signals that are later transmitted or received. The primary objectives of this study are to demonstrate that the technique of the previous study can be generalized by applying it successively to multiple signal types, to demonstrate that the procedure for optimizing the frequency correction factors of the previous study can be used for each of the multiple components or signal types of the generalized technique, and to illustrate by examples the performance improvement achieved by using the generalized technique with multiple signal types as opposed to the single-component technique based on one signal type. >