Investigation of the multipath effect on the estimation of the GNSS signal parameters using simulator of navigation field

Аuthors

Konstantinov A. A.

Moscow Aviation Institute (National Research University), 4, Volokolamskoe shosse, Moscow, А-80, GSP-3, 125993, Russia

e-mail: sasha_konst@pochta.ru

Abstract

The purpose of this work is to develop the technique, by which one can effectively develop software to realize mathematical tool for aerodynamic forces simulator with FPGA.

To develop this technique we carry out system analysis of the aerodynamic equation, which constitutes a part of the aerodynamic forces (AFS) simulator. This analysis resulted in selection of integral form of the equation for further implementation with FPGA. We performed discretization of the equations, and reduced them to fixed-point arithmetic. To increase the speed of algorithm operation, we replace division operator with binary shift. While developing the technique we used existing recommendations for FPGA programming in LabVIEW.

After implementation of the developed technique a list of typical mathematical operations and methods of their implementation, based on the analysis of the equations included into the algorithm are formed. In addition the separation of slowly varying and rapidly varying parameters calculations is performed.

Implementation of this technique during aerodynamic forces simulator design allowed to increase the speed of the algorithm for eight interconnected channels from 17.7kHz to 416.6 kHz, which corresponds to 24 times increase in performance. To obtain the results we used National Instruments equipment: eight-channel analog-to-digital converter (ADC) with 16 bit resolution and sampling rate of 750 kHz as well as eight-channel digital-to-analog converter (DAC) with 16 bit resolution and sampling rate of 1 MHz.

The proposed technique can be implemented during various measurement and information as well as management systems design, with severe requirements for operation speed, accuracy and channeling with explicit synchronization of execution.

Keywords:

programmable logic integrated circuit, digital-to-analog convertor, aerodynamic forces simulator, analog-to-digital convertor, electromechanical modeling method

References

1. Karkleh P.G., Malyutin V.А., Mamedov O.S., Popovskij V.N., Smotrov А.V., Smyslov V.I. Trudy Tsentralnogo Аehrogidrodinamicheskogo instituta, 2012, vol. 2708. pp. 1-35.
2. Karkleh P.G., Smyslov V.I.. Polet, 2008, no.10. pp. 25-31.
3. Baran E. D. LabVIEW FPGA. Rekonfiguriruemye izmeritelnye i upravlyayushchie sistemy (Configurable measuring and control systems), Moscow, DMK Press, 2009, 448p.
4. Pisaruk N. N. Kratchajshie puti v grafakh, http://pisaruk.narod.ru/slides/shortPath.pdf (accessed 29.09.14).

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