International Global Navigation Satellite Systems Society
IGNSS Symposium 2015
Colombo Theatres, Kensington Campus, UNSW Australia
6 8 December 2016
The effect of sampling frequency and front-end
bandwidth on the DLL code tracking performance
Vinh T Tran
Australian Centre for Space Engineering Research
University of New South Wales, Sydney, Australia
Nagaraj C Shivaramaiah
University of Colorado at Boulder, USA
Thuan D Nguyen
NAVIS centre, Hanoi University of Science and Technology, Hanoi, Viet Nam
Andrew G Dempster
Australian Centre for Space Engineering Research
University of New South Wales, Sydney, Australia
ABSTRACT
The synchronization of the received pseudorandom (PRN) code and the local
generated replica is fundamental to compute user position in Global Naviga-
tion Satellite System (GNSS) receivers. The more accurate correlation output
and Delay Locked Loop (DLL) code tracking error are described in this paper
from the hardware receiver point of view. Estimation is based on the number
of samples per code chip and the residual code phase of the code Numerical
Controlled Oscillator (NCO) after a code chip is generated. The theoretical
as well as experiment results show that the relation between the sampling fre-
quency and front-end filter bandwidth has a strong influence in the code track-
ing. Increasing the sampling frequency can help to improve the DLL tracking
performance if and only if the front-end bandwidth is much smaller than the
sampling frequency. The more accurate estimation of the correlation and the
DLL tracking error, proposed in this paper, can generally apply on precisely
modeling GNSS receiver baseband signal processing.
1 Introduction
Global Navigation Satellite System (GNSS) receiver technology has changed dramatically since
the first reception of Global Positioning System (GPS) signals, from complex and partly-analogue
circuits to sophisticated, small, multichannel digital receivers or fully software defined radio ar-
chitectures as presented in (Tran et al., 2016a). However, the navigation concept is still based
on the estimation of the range between the user position to a set of at least 4 satellites using
