TY - EJOU
AU - Jwo, Dah-Jing
AU - Chiu, Sheng-Feng
TI - Data Wipe-Off Technique for Tracking Weak GPS Signals
T2 - Computers, Materials \& Continua
PY - 2022
VL - 70
IS - 3
SN - 1546-2226
AB - In this paper, the data wipe-off (DWO) algorithm is incorporated
into the vector tracking loop of the Global Positioning System (GPS) receiver
for improving signal tracking performance. The navigation data, which contains information that is necessary to perform navigation computations, are
binary phase-shift keying (BPSK) modulated onto the GPS carrier phase with
the bit duration of 20 ms (i.e., 50 bits per second). To continuously track the
satellite’s signal in weak signal environment, the DWO algorithm on the basis
of pre-detection method is adopted to detect data bit sign reversal every 20
ms. Tracking accuracy of a weak GPS signal is decreased by possible data
bit sign reversal every 20 ms to the predetection integration time (PIT) or
integration interval. To achieve better tracking performance in weak signal
environment, the coherent integration interval can be extended. However,
increase of the integration interval lead to decrease of the tracking accuracy
by possible data bit sign reversal every 20 ms to the integration interval. When
the integration interval of the correlator is extended over 20 ms in low C/No
levels, the navigation DWO algorithm can be employed to avoid energy loss
due to bit transitions. The method presented in this paper has an advantage to
continuously estimate the navigation data bit and achieve improved tracking
performance. Evaluation of the tracking performance based on the various
integration intervals for the vector tracking loop of a GPS receiver will be
presented.
KW - Global positioning system (GPS); integration interval; data wipe-off; weak signal
DO - 10.32604/cmc.2022.020793