Next Article in Journal
Fourier Transform Infrared Spectroscopy (FT-IR) and Simple Algorithm Analysis for Rapid and Non-Destructive Assessment of Developmental Cotton Fibers
Previous Article in Journal
Bluetooth Low Energy Mesh Networks: A Survey
Article Menu
Issue 7 (July) cover image

Export Article

Open AccessArticle
Sensors 2017, 17(7), 1468;

A Carrier Estimation Method Based on MLE and KF for Weak GNSS Signals

School of Aerospace Science and Technology, Xidian University, Xi’an 710126, China
School of Information and Communication, Guilin University of Electronic Technology, Guilin 541004, China
Author to whom correspondence should be addressed.
Received: 10 April 2017 / Revised: 8 June 2017 / Accepted: 16 June 2017 / Published: 22 June 2017
(This article belongs to the Section Remote Sensors)
Full-Text   |   PDF [2680 KB, uploaded 22 June 2017]   |  


Maximum likelihood estimation (MLE) has been researched for some acquisition and tracking applications of global navigation satellite system (GNSS) receivers and shows high performance. However, all current methods are derived and operated based on the sampling data, which results in a large computation burden. This paper proposes a low-complexity MLE carrier tracking loop for weak GNSS signals which processes the coherent integration results instead of the sampling data. First, the cost function of the MLE of signal parameters such as signal amplitude, carrier phase, and Doppler frequency are used to derive a MLE discriminator function. The optimal value of the cost function is searched by an efficient Levenberg–Marquardt (LM) method iteratively. Its performance including Cramér–Rao bound (CRB), dynamic characteristics and computation burden are analyzed by numerical techniques. Second, an adaptive Kalman filter is designed for the MLE discriminator to obtain smooth estimates of carrier phase and frequency. The performance of the proposed loop, in terms of sensitivity, accuracy and bit error rate, is compared with conventional methods by Monte Carlo (MC) simulations both in pedestrian-level and vehicle-level dynamic circumstances. Finally, an optimal loop which combines the proposed method and conventional method is designed to achieve the optimal performance both in weak and strong signal circumstances. View Full-Text
Keywords: GNSS receiver; High sensitivity; MLE; KF GNSS receiver; High sensitivity; MLE; KF

Figure 1

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (CC BY 4.0).

Share & Cite This Article

MDPI and ACS Style

Zhang, H.; Xu, L.; Yan, B.; Zhang, H.; Luo, L. A Carrier Estimation Method Based on MLE and KF for Weak GNSS Signals. Sensors 2017, 17, 1468.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics



[Return to top]
Sensors EISSN 1424-8220 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top