A frequency tracking technique for multiple access satellite communication networks

A satellite communication system may employ frequency tracking mechanisms at each earth terminal to control transmit frequency and tuned receiver frequency. The technique presented is applicable to time division multiplexed systems having burst transmissions. Frequency tracking can provide corrections for frequency offsets due to Doppler, oscillator inaccuracies, satellite inclination angle effects, and other factors. One objective of such frequency tracking is to minimize the width of the receive frequency window that must be searched. Reducing the width of this window will in general allow the use of a more efficient waveform, or will improve signal acquisition performance for a given waveform. A general technique is presented for characterizing any number of frequency error sources, and determining optimum constant correction factors based on the characterized error sources and parameters of a given system. Optimized correction factors and associated worst-case frequency offsets are then evaluated for example UHF networks