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Beam pattern overview for GPS signals (15, 10), (15, 70), (15,130), (15,190), (15,250), (15,310), Pseudolite signals (85, 25), (85, 85), (85,145), (85,205), (85,265), (85,325) and interference (20, 10), (20, 70), (20,130), (20,190), (20,250), (20,310).
Source publication
In order to improve signal reception performance in GPS/INS/PL (Pseudolite) integration applications, a semi-sphere antenna array is proposed in this paper. It inherits the wide coverage characteristic of conventional spherical arrays and utilizes only about half the number of elements compared to a planar array to cover the upper-semi-sphere space...
Context in source publication
Context 1
... C , f are the signal steering vectors and corresponding constraints respectively; the equation satisfies C H W = f . For validations, the beam patterns of symmetrical signal distributions are simulated. In Figure 8, 6 BPSK modulated signals clustered around vertex act as GPS/Pseudolite signals with angles (15, 10), (15, 70), (15,130), (15,190), (15,250), (15,310); 6 BPSK modulated signals from the horizon take the role of Pseudolite signals with angles (85, 10), (85, 70), (85,130), (85,190), (85,250), (85,310); 6 BPSK modulated signals at angles (45, 10), (45, 70), (45,130), (45,190), (45,250), (45,310) are considered as interferences; and a DOA 3D spectrum is plotted. From this figure, it can be concluded that the array is not very effective in receiving the signals from horizon. With GPS and interference signals direction fixed, the direction of Pseudolite signals are increased by 15 0 , and the result is shown in Figure 9. It can be seen that both signal reception and interference rejection have been improved. With GPS and Pseudolite signals direction fixed, the directions of interferences are decreased to 20 0 , and the result is plotted in Figure 10. It can be seen that the horizontal signal reception becomes weaker. In this paper, a semi-sphere array for GPS/INS/PL integration is proposed. The basis expressions are derived for this proposed new antenna array. The proposed semi-sphere antenna array not only receives signals from satellites and Pseudolites from all directions, but also from the horizon. Combined with adaptive processing, these semi-sphere antenna arrays based GPS, or GPS/PL, GPS/INS/PL integration receivers will possess strong anti-jamming capability. Therefore, to mitigate the multipath and interference signals, and also to receive low elevation Pseudolite signals, this antenna array can be widely used in various applications. Simulation results on both the DOA estimation and beam-forming demonstrated that the array can simultaneously process multiple signals from arbitrary directions in the upper semi-sphere. The power effect and spatial distribution effect of signals to the DOA spectrum and beam pattern were also analysed. To summarize, this property of the semi-sphere antenna makes it very attractive in GPS based applications, including GPS/INS/PL integration. This research is partly supported by an ARC (Australian Research Council) – Discovery Research Project on ‘Robust Positioning Based on Ultra-tight Integration of GPS, Pseudolites and Inertial Sensors’. Amin M, Sun W, and Lindsey A (2003) Adaptive arrays for GPS receivers , in Ibnkahla M.Ed., Signal Processing for Mobile Communications Handbook, CRC Press. Capon J (1969) High-resolution frequency-wave number spectrum analysis , Proc. IEEE, 57:1408-1418. Enge P (1999) Local area augmentation of GPS for the precision approach of aircraft , Proc. IEEE, 87(1)111-132. Kaplan ED (1996) Understanding GPS: Principles and Applications , Artech House, Inc. Wang J, Dai L, Tsuiji T, Rizos C, Grejner-Brzezinska D, Toth C (2001) GPS/INS/Pseudolite Integration: Concepts, Simulation and Testing. 14 th Int. Tech. Meeting of the Satellite Division of the U.S. Inst. of Navigation, Salt Lake City, Ohio, 11-14 September, 2708- 2715. Malmström J (2003) Robust Navigation with GPS/INS and Adaptive Beamforming , Scientific Report, FOI-R—0848—SE, Swedish Defence Research Agency, Sweden. Brown A. and Gerein N (2001) Test Results of a Digital Beamforming GPS Receiver in a Jamming Environment , ION GPS 2001, 11-14 September 2001, Salt Lake City, UT, 894- ...
Citations
... One of the firstly reported commercial platforms was NAVSYS Corporation's High Gain Advanced GPS Receiver (HAGR) [72], which was composed of a 16-element antenna array receiver and used dedicated hardware to create up to 12 independent and parallel beamformings to simultaneously point the array beams towards 12 GPS satellites. Similar architectures were reported in [73]- [77], as well as combined with inertial navigation [78], [79] and attitude determination systems [80], [81]. ...
One of the main vulnerabilities of GNSS receivers is their exposure to intentional or unintentional jamming signals, which could even cause service unavailability. Several alternatives to counteract these effects were proposed in the literature, being the most promising those based on multiple antenna architectures. This is specially the case for high-grade receivers used in applications requiring reliability and robustness. This article provides an overview of the possible receiver architectures encompassing antenna arrays and the associated signal processing techniques. Emphasis is also put on the most typical implementation issues found when dealing with such technology. A thorough survey is complemented with a set of experiments, including real data processing by a working prototype, which exemplifies the above ideas.
In many communication scenarios, such as in GPS communications and integrated navigation systems, signals with wide space distributions need to be processed simultaneously or promptly. Hemispherical arrays have greater capability in receiving and processing signal than planar arrays, and can provide robust performance. In previous research, the directivity of a hemispherical array is compared with several kinds of planar arrays, that shows this kind of array has essentially better scanning performance. In this paper, the effect of element pattern on the hemispherical array's scanning directivity is studied, and the main factors which affect the parameters of directivity are analysed and the effects of these factors on directivity are discussed. Simulation results are presented for illustration.
Hemispherical arrays are charming in receiving and processing multiple signals with wide space distributions and thus provide robust performance for integrated navigation systems. Previous research [D. Li et al, 2005] shows this kind of array has better scanning directivity. In this paper, a geometry-optimized hemispherical array is studied on directivity and multiple signals/jammers adaptive processing. A practical switch network used to reduce activated elements number and thus cost is also proposed. Simulation examples are presented to illustrate its performance.
Hemispherical arrays are charming in receiving and processing multiple signals with wide space distributions, especially in integrated navigation systems. In this paper the directivity of a hemispherical array is compared with several kinds of planar array. It shows that the hemispherical array has an attractive scanning directivity performance through the hemi-space above earth plane, especially with small numbers of elements. The effect of element pattern, element number and minimal element spacing is discussed.
