TY - JOUR
T1 - Sensitivity and performance analysis of doppler-aided GPS carrier-tracking loops
AU - Gebre-Egziabher, Demoz
AU - Razavi, Alireza
AU - Enge, Per K.
AU - Gautier, Jennifer
AU - Pullen, Sam
AU - Pervan, Boris S.
AU - Akos, Dennis M.
PY - 2005
Y1 - 2005
N2 - The performance of a Doppler-aided GPS receiver is analyzed. It is shown that Doppler aiding increases the receiver's robustness to interference and jamming. This is achieved by narrowing the noise bandwidth of the carrier-tracking loop using an external estimate of the Doppler shift of the GPS signal. The Doppler estimate is computed using an inertial navigation system and is incorporated into the carrier-tracking loop in a feed-forward fashion. The minimum achievable loop bandwidth is a function of phase noise on the receiver oscillator, satellite clock phase noise, and the quality of the external Doppler estimate. Using the criterion for loss of lock of 15 deg phase jitter, it is shown analytically that for an unaided receiver, loss of lock occurs at a signal power equal to approximately 26 dB-Hz. With Doppler aiding and a nominal-quality receiver clock, an additional 4 dB-Hz margin can be achieved, allowing signals with power as low as 22 dB-Hz to be tracked.
AB - The performance of a Doppler-aided GPS receiver is analyzed. It is shown that Doppler aiding increases the receiver's robustness to interference and jamming. This is achieved by narrowing the noise bandwidth of the carrier-tracking loop using an external estimate of the Doppler shift of the GPS signal. The Doppler estimate is computed using an inertial navigation system and is incorporated into the carrier-tracking loop in a feed-forward fashion. The minimum achievable loop bandwidth is a function of phase noise on the receiver oscillator, satellite clock phase noise, and the quality of the external Doppler estimate. Using the criterion for loss of lock of 15 deg phase jitter, it is shown analytically that for an unaided receiver, loss of lock occurs at a signal power equal to approximately 26 dB-Hz. With Doppler aiding and a nominal-quality receiver clock, an additional 4 dB-Hz margin can be achieved, allowing signals with power as low as 22 dB-Hz to be tracked.
UR - http://www.scopus.com/inward/record.url?scp=33750290343&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=33750290343&partnerID=8YFLogxK
U2 - 10.1002/j.2161-4296.2005.tb01731.x
DO - 10.1002/j.2161-4296.2005.tb01731.x
M3 - Article
AN - SCOPUS:33750290343
SN - 0028-1522
VL - 52
SP - 49
EP - 60
JO - Navigation, Journal of the Institute of Navigation
JF - Navigation, Journal of the Institute of Navigation
IS - 2
ER -