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Traditional global navigation satellite system (GNSS) terminals for satellite navigation adopt independent channels to track the signals from different satellites, which results in a lack of information interaction between the channels. Inspired by the vector tracking idea, and drawing lessons from the principle that in the position domain the Taylor expanded pseudorange observations can be used for positioning via the least squares method, this paper proposes a novel least squares-based multi-channel parameter joint estimation (MPJE) method in the signal domain, which not only retains the advantages of channel fusion, but also maintains the flexibility and diversity of the localization algorithm. With achieving optimal carrier to noise ratio as the goal, the proposed method obtains the required code loop and carrier loop parameters for signal tracking in the domain of whole channels. Experimental results indicate that this method fully achieves the assistant fusion advantages of frequency lock loop (FLL), phase lock loop (PLL) and delay lock loop (DLL), making good use of the robustness and dynamic properties of the FLL and the measurement accuracy of the DLL, and is helpful for achieving stable and accurate signal tracking under weak signals and high dynamic stress environments. [ABSTRACT FROM AUTHOR]

With the continuous development of global navigation satellite system (GNSS), the combined multi-system receiver autonomous integrity monitoring (RAIM) has been an important topic based on BDS/GPS/GLONASS/Galileo. The algorithm of Multi-GNSS RAIM availability was proposed, and the availability of a combined multi-system RAIM based on simulated navigation ephemeris of BDS/Galileo and actual navigation ephemeris of GPS/ GLONASS was analyzed in precise approach procedures. Results show that five geosynchronous orbit (GEO) satellites and three inclined geosynchronous orbits (IGSO) satellites from BDS make a great contribution to RAIM availability. The eight satellites improve the geometry structure of the constellation in the most parts of Asia, Africa and Europe, and promote RAIM availability greatly. In the Asia-Pacific region, the RAIM availability of BDS reaches 99.5%, higher than that of the other three navigation system at APV-I phase. In precise approach phases (APV-I, APV-II and CAT-1), the integrated BDS/ GPS/ Galileo/GLONASS can meet the requirements of RAIM availability in a global scale. [ABSTRACT FROM AUTHOR]

Adaptive antenna arrays have been used to mitigate the interference on global navigation satellite system (GNSS) receivers. The performance of interference mitigation depends on the beamforming algorithms adopted by the antenna array. However, the adaptive beamforming will change the array pattern in real-time, which has the potential to introduce phase center biases into the antenna array. For precise applications, these phase biases must be mitigated or compensated because they will bring errors in code phase and carrier phase measurements. A novel adaptive beamforming algorithm is proposed firstly, then the phase bias induced by the proposed algorithm is estimated, and finally a compensation strategy is addressed. Simulations demonstrate that the proposed beamforming algorithm suppresses effectively the strong interference and improves significantly the capturing performance of GNSS signals. Simultaneously, the bias compensation method avoids the loss of the carrier phase lock and reduces the phase measurement errors for GNSS receivers. [ABSTRACT FROM AUTHOR]