A Low Complexity Navigation Data Estimation Algorithm for Weak GNSS Signal Tracking
Abstract: The computation load
of traditional navigation data estimation algorithms for weak GNSS signal tracking
increases exponentially with respect to the number of data bits needed to be
estimated. To solve this problem, by adopting the dynamic programming
philosophy, a navigation data bits estimation algorithm is proposed. The
proposed algorithm uses the partial sum of correlation values as data bit combination
searching branches. It can predict and exclude searching branches of data bit
combination which have small coherent accumulated energy as soon as possible by
angle quantification, thus reducing its computation load to be linearly related
to the number of data bits needed to be estimated. Simulation results show that
for signal of 500bps navigation data rate, the carrier track loop with a
frequency discriminator implementing 0.12s coherent accumulation by navigation
data estimation improves the tracking sensitivity up to 7 dB compared with
traditional frequency discriminator under the same track accuracy constraint.
Author: Shunxiao Wu, Yangbo
Huang, Shaojie Ni, Gang Ou
Journal Code: jptkomputergg150061
