Frequency Tracking a Downlink FH Signal for Mobile Platforms
Richard S. Orr · 1983
A mobile platform receiving a frequency hopped (FH) downlink must acquire and track that link to sustain communications. A technique originated by Ziv and Zakai allows us to lower bound the achievable frequency error for a variety of channel conditions (Gaussian, partial-band, Raleigh). In closed loop space-to-ground tracking systems which have an FH uplink as well, frequency precorrection may be needed on each of the terminal's transmissions. The frequency error model developed in this paper is used in combination with models of other frequency error sources to yield analysis that can aid in selecting tracking update rates.