scholarly journals Expressions for the Autocorrelation Function and Power Spectral Density of BOC Modulation Based on Convolution Operation

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Jiangang Ma ◽  
Yikang Yang ◽  
Hengnian Li ◽  
Jisheng Li
Keyword(s):  
High Performance ◽  
Algorithm Design ◽  
Satellite System ◽  
Binary Offset Carrier ◽  
Simulation Performance ◽  
Convolution Operation ◽  
Power Spectral ◽  
Signal Simulation ◽  
The Fourier Transform ◽  
Global Navigation Satellite

We present universal expressions for the autocorrelation functions (ACFs) of the Binary Offset Carrier (BOC), Multiplexed BOC (MBOC), and Alternative BOC (AltBOC) modulations based on convolution operations. We also derive the expressions for the power spectrum densities (PSDs) of these modulations using the Fourier transform of their ACFs. The results obtained in this contribution are useful for Global Navigation Satellite System (GNSS) signal simulation, performance evaluation, and high-performance acquisition and tracking algorithm design. The derivation methods of the expressions for the ACFs are common and can be used to derive expressions for the ACFs of other BOC-based modulations.

scholarly journals A Fine-Tuned Positioning Algorithm for Space-Borne GNSS Timing Receivers

Sensors ◽  
2020 ◽  
Vol 20 (8) ◽  
pp. 2327 ◽  
Author(s):  
Xi Chen ◽  
QiHui Wei ◽  
YaFeng Zhan ◽  
TianYi Ma
Keyword(s):  
High Performance ◽  
Algorithm Design ◽  
Satellite System ◽  
Frequency Error ◽  
Satellite Position ◽  
Cubature Kalman Filter ◽  
Rms Error ◽  
Adverse Influence ◽  
Global Navigation Satellite ◽  
Positioning Algorithm

To maximize the usage of limited transmission power and wireless spectrum, more communication satellites are adopting precise space–ground beam-forming, which poses a rigorous positioning and timing requirement of the satellite. To fulfill this requirement, a space-borne global navigation satellite system (GNSS) timing receiver with a disciplined high-performance clock is preferable. The space-borne GNSS timing receiver moves with the satellite, in contrast to its stationary counterpart on ground, making it tricky in its positioning algorithm design. Despite abundant existing positioning algorithms, there is a lack of dedicated work that systematically describes the delicate aspects of a space-borne GNSS timing receiver. Based on the experimental work of the LING QIAO (NORAD ID:40136) communication satellite’s GNSS receiver, we propose a fine-tuned positioning algorithm for space-borne GNSS timing receivers. Specifically, the proposed algorithm includes: (1) a filtering architecture that separates the estimation of satellite position and velocity from other unknowns, which allows for a first estimation of satellite position and velocity incorporating any variation of orbit dynamics; (2) a two-threshold robust cubature Kalman filter to counteract the adverse influence of measurement outliers on positioning quality; (3) Reynolds averaging inspired clock and frequency error estimation. Hardware emulation test results show that the proposed algorithm has a performance with a 3D positioning RMS error of 1.2 m, 3D velocity RMS error of 0.02 m/s and a pulse per second (PPS) RMS error of 11.8ns. Simulations with MATLAB show that it can effectively detect and dispose outliers, and further on outperforms other algorithms in comparison.

Estimation of the scale lengths of turbulence from GPS single difference phase observations 

2021 ◽  
Author(s):  
Gaël Kermarrec ◽  
Steffen Schön
Keyword(s):  
Satellite System ◽  
Index Of Refraction ◽  
Empirical Modeling ◽  
Free Atmosphere ◽  
Phase Measurements ◽  
Power Spectral ◽  
Satellite Geometry ◽  
Global Navigation Satellite ◽  
Kolmogorov Theory ◽  
Single Differences

<p>Signals from the Global Navigation Satellite System (GNSS) travel through the whole atmosphere and encounter fluctuations of the index of refraction. The long-term variations of the tropospheric refractive index delay the signals, whereas its random variations correlate with the phase measurements. The power spectral density of microwave phase difference can be derived from physical considerations by combining results from the Kolmogorov theory and electromagnetic wave propagation. Four different dominant noise regimes are expected. Their cutoff frequencies can be estimated with the unbiased Whittle Maximum Likelihood estimator; They provide information about the scale lengths of turbulence which are directly linked with the size of the eddies or swirling motion present in the free atmosphere. Dependencies of these parameters with the satellite geometry or the time of the day pave the way for a better comprehension of how tropospheric turbulence acts as correlating GNSS phase observations. The result is less empirical modeling of GNSS phase correlations to improve the positioning results and avoid an overestimation of their precision. We use GPS single differences from 290 m distant antenna positions recorded during two days in 2013 in a common clock experiment at the Physikalisch Technische Bundesanstalt in Braunschweig Germany to explain our methodology, based on adequate filtering of the residuals to mitigate multipath effects.</p>

Signal Structure and Simulation of Compass Satellite Navigation System

2013 ◽  
Vol 390 ◽  
pp. 485-489
Author(s):  
Z. Huang ◽  
H. Yuan
Keyword(s):  
Navigation System ◽  
Satellite Navigation ◽  
Satellite System ◽  
Signal Design ◽  
Characteristic Analysis ◽  
Binary Offset Carrier ◽  
Satellite Navigation System ◽  
Signal Structure ◽  
Power Spectral ◽  
Compass System

Due to Chinas compass satellite navigation system which is under development, signals will be designed to obey some constraints and cooperate with other satellite system. Binary offset carrier BOC characterizing good correlation, band sharing and spectral separability is proposed for Compass system. Signal structure and development of Compass system is first analyzed in this paper, and then the principles of several BOC modulations are elaborated. The emphasis is put on a characteristic analysis of power spectral density and autocorrelation function. Further, the frequency spectrum of AltBOC modulation is simulated with Matlab due to B2 signal structure. The simulation results will be instructive meaning for compass phase Ш signal design and engineer implementation.

scholarly journals Galileo E5 AltBOC Signals: Application for Single-Frequency Total Electron Content Estimations

2021 ◽  
Vol 13 (19) ◽  
pp. 3973
Author(s):  
Artem M. Padokhin ◽  
Anna A. Mylnikova ◽  
Yury V. Yasyukevich ◽  
Yury V. Morozov ◽  
Gregory A. Kurbatov ◽  
...  
Keyword(s):  
Total Electron Content ◽  
Noise Level ◽  
Satellite System ◽  
Single Frequency ◽  
Electron Content ◽  
Dual Frequency ◽  
Binary Offset Carrier ◽  
Total Electron ◽  
Galileo E5 ◽  
Global Navigation Satellite

Global navigation satellite system signals are known to be an efficient tool to monitor the Earth ionosphere. We suggest Galileo E5 AltBOC phase and pseudorange observables— a single-frequency combination—to estimate the ionospheric total electron content (TEC). We performed a one-month campaign in September 2020 to compare the noise level for different TEC estimations based on single-frequency and dual-frequency data. Unlike GPS, GLONASS, or Galileo E5a and E5b single-frequency TEC estimations (involving signals with binary and quadrature phase-shift keying, such as BPSK and QPSK, or binary offset carrier (BOC) modulation), an extra wideband Galileo E5 AltBOC signal provided the smallest noise level, comparable to that of dual-frequency GPS. For elevation higher than 60 degrees, the 100-sec root-mean-square (RMS) of TEC, an estimated TEC noise proxy, was as follows for different signals: ~0.05 TECU for Galileo E5 AltBOC, 0.09 TECU for GPS L5, ~0.1TECU for Galileo E5a/E5b BPSK, and 0.85 TECU for Galileo E1 CBOC. Dual-frequency phase combinations provided RMS values of 0.03 TECU for Galileo E1/E5, 0.03 and 0.07 TECU for GPS L1/L2 and L1/L5. At low elevations, E5 AltBOC provided at least twice less single-frequency TEC noise as compared with data obtained from E5a or E5b. The short dataset of our study could limit the obtained estimates; however, we expect that the AltBOC single-frequency TEC will still surpass the BPSK analogue in noise parameters when the solar cycle evolves and geomagnetic activity increases. Therefore, AltBOC signals could advance geoscience.

scholarly journals Application of Inertial and GNSS Integrated Navigation to Seabird Biologging

2021 ◽  
Vol 33 (3) ◽  
pp. 526-536
Author(s):  
Masaru Naruoka ◽  
Yusuke Goto ◽  
Henri Weimerskirch ◽  
Takashi Mukai ◽  
Taichi Sakamoto ◽  
...  
Keyword(s):  
Power Consumption ◽  
High Performance ◽  
Feasible Solution ◽  
Satellite System ◽  
Integrated Navigation ◽  
Guidance And Control ◽  
Marine Vehicles ◽  
Navigation Algorithm ◽  
Global Navigation Satellite ◽  
And Control

The study demonstrates the versatility of integration of inertial navigation and global navigation satellite system (GNSS) with its unique application to seabird biologging. Integrated navigation was originally developed in the field of aerospace engineering, which requires accurate and reliable position, velocity, and attitude information for the guidance and control of aircraft and spacecraft. Due to its high performance and recent progress of sensor development, integrated navigation has been widely used not only in aerospace but also in many fields represented by land and marine vehicles. One of its ultimate applications under the constraint on the size and power consumption of devices is this study. Seabird biologging involves attaching a logging device onto a seabird for scientific purposes to understand its biomechanics, behavior, and so on. Design restrictions for the device include several tens of grams mass, several tens of millimeters in length, and several tens of milliamperes of power consumption. It is more difficult to maintain the accuracy of such a device than applications to an artificial vehicle. This study has shown that integrated navigation is a feasible solution for such extreme applications with two examples: biologging for wandering albatrosses and great frigatebirds. Furthermore, it should be stressed that the navigation captured the world’s first data of their detailed trajectories and attitudes in their dynamic and thermal soarings. For completeness, the navigation algorithm, simulation results to show the effectiveness of the algorithm, and the logging devices attached to bird are also described.

scholarly journals The Galileo Ground Segment Integrity Algorithms: Design and Performance

2008 ◽  
Vol 2008 ◽  
pp. 1-16 ◽  
Author(s):  
Carlos Hernández Medel ◽  
Carlos Catalán Catalán ◽  
Miguel Angel Fernández Vidou ◽  
Esther Sardón Pérez
Keyword(s):  
Algorithm Design ◽  
Satellite System ◽  
Navigation Satellite ◽  
Safety Requirements ◽  
Ground Segment ◽  
Global Positioning ◽  
Processing Facility ◽  
And Performance ◽  
Global Navigation Satellite ◽  
Software Prototype

Galileo, the European Global Navigation Satellite System, will provide to its users highly accurate global positioning services and their associated integrity information. The element in charge of the computation of integrity messages within the Galileo Ground Mission Segment is the integrity processing facility (IPF), which is developed by GMV Aerospace and Defence. The main objective of this paper is twofold: to present the integrity algorithms implemented in the IPF and to show the achieved performance with the IPF software prototype, including aspects such as: implementation of the Galileo overbounding concept, impact of safety requirements on the algorithm design including the threat models for the so-called feared events, and finally the achieved performance with real GPS and simulated Galileo scenarios.

scholarly journals Modified WiFi-RSS Fingerprint Technique to locate Indoors-Smartphones: FENG building at Koya University as a case study

2017 ◽  
Vol 2 (3) ◽  
pp. 212-217 ◽  
Author(s):  
Halgurd S. Maghdid ◽  
Ladeh Sardar Abdulrahman ◽  
Mohammed H. Ahmed ◽  
Azhin Tahir Sabir
Keyword(s):  
Global Positioning System ◽  
High Performance ◽  
Low Cost ◽  
Satellite System ◽  
Positioning System ◽  
Global Positioning ◽  
Accurate Position ◽  
Global Navigation Satellite ◽  
Gps System

Positioning system used for different purposes and different services, many researches are going on to find a more accurate position with low error within high performance. There are many localization solutions with different architectures, configurations, accuracies and reliabilities for both outdoors and indoors. For example, Global Navigation Satellite System (GNSS) technology has been used for outdoors.  Global Positioning System (GPS) is one of the most common outdoors tracking solutions in the world, for outdoors, however, when indoors; it could not be accurately tracked users by using a GPS system. This is because, when users enters into indoors the GPS signals will no longer available due to blocked by the roof of buildings and it is no longer considered as a viable option.  WiFi Positioning System (WPS) can be used as an alternative solution to define users’ position, especially when GPS signal is not available. Further, WPS is a low cost solution, because there is no need to deploying WiFi Access Points (WAPs) in the vicinity, as they are installed to access the Internet. In this paper, specifically, WiFi-RSS Fingerprinting technique is used to locate smartphones using WAPs signals with a modified calculation. The new modified calculation is to dynamic weighting of the WAPs RSS values based on the real-live indoors structure. The achieved positioning accuracy, based on several trial experiments, is up to 6 meters via the implemented algorithm in the MALTAB.

scholarly journals Unambiguous Multipath Mitigation Technique for BOC(n,n) and MBOC-Modulated GNSS Signals

2012 ◽  
Vol 2012 ◽  
pp. 1-13 ◽  
Author(s):  
Khaled Rouabah ◽  
Mustapha Flissi ◽  
Salim Attia ◽  
Djamel Chikouche
Keyword(s):  
Satellite System ◽  
Delay Estimation ◽  
Line Of Sight ◽  
Likelihood Estimator ◽  
Multipath Mitigation ◽  
Binary Offset Carrier ◽  
Efficient Scheme ◽  
The Common ◽  
Global Navigation Satellite ◽  
Mitigation Technique

We propose an efficient scheme for side peaks cancelation and multipath (MP) mitigation in binary offset carrier (n,n) (BOC(n,n)) and multiplexed BOC (MBOC) modulated signals. The proposed scheme reduces significantly the band of variation of MP errors in global navigation satellite system (GNSS). It consists of two versions. The first one is based on the use of maximum likelihood estimator (MLE) of MP signals and reference correlation functions (CFs) like that of pseudorandom noise (PRN) code without BOC subcarrier. In the second version, the former (MLE) is used with the reference BOC(n,n) or MBOC CFs. Unlike traditional BOC(n,n) and MBOC, that have CFs containing multiple peaks leading to potential tracking ambiguities, our proposed scheme does not contain any side peaks. In addition, all the MP signals with medium and long delays have no effect on the estimation of the pseudorange. On the other hand, all the methods proposed for mitigating MP in no-BOC scheme are practical for our scheme due to its CF which is similar to that of the PRN code. The computer simulation results show that the proposed scheme has superior performances in the reduction of the errors produced in the process of the delay estimation of line of sight (LOS) and caused by MP propagation. In fact, the performances of the proposed scheme are better with regard to that of the traditional BOC(n,n) and MBOC. Moreover, in the presence of noise, our proposed scheme keeps better performances than the common side peaks cancelation methods.

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