Real time implementation of software defined GNSS receiver

Project Title

Real time implementation of software defined GNSS receiver

Project Area of Specialization Electrical/Electronic EngineeringProject Summary

GNSS (Global Navigation Satellite System) is generally used to describe the collection of various satellite positioning systems. The GNSS provides three-dimensional position, velocity, and time information to users – accurately and continuously – with the appropriate receiving equipment at regional or worldwide level [1]. A GNSS software receiver is a real-time GNSS receiver that does all the signal processing after down-conversion and sampling on a general-purpose processor (which can either be part of an embedded platform or part of a standalone computer). Some small part of the signal conditioning (e.g., IF filtering or sample rate reduction) and/or signal processing can be done on an FPGA. If the signal processing is done on an ASIC, then the receiver is called hardware receiver. Such hardware receivers work on a low-resolution sample (around 2 bits per sample) of the received signal. This received signal is processed as a stream (e.g., older signal samples are not available for a reiteration). Development effort of such receivers is usually high [2]. These limitations are not intrinsically hardware-receiver specific but can be solved more easily with a software solution.

The hardware platform (on which the software defined GNSS is implemented) determines real-time performance parameters like size, power consumption, and number of correlators. If only COTS (commercial off-the-shelf) components are used, these parameters are normally far from optimal. On the other hand, wisely chosen processors integrated into an optimized board may outperform classical ASIC correlator chip solutions for certain applications.

This project will be based on an open-source software defined GNSS receiver which will be implement on an embedded platform with the goal to have real time and performance wise efficient implementation [3]. The scope of this project does not include development of the GNSS receiver software itself.

[1] Novatel, “An Introduction to GNSS GPS, GLONASS, BeiDou, Galileo and other Global Navigation Satellite Systems,” 2nd Ed, 2015.

[2] Pany, Thomas., “Navigation signal processing for GNSS software receivers,” Artech House, 2010.

[3] C. Fernández-Prades, J. Arribas, P. Closas, C. Avilés, and L. Esteve, “GNSS-SDR: an open-source tool for researchers and developers,” Proceedings of the 24th International Technical Meeting of The Satellite Division of the Institute of Navigation (ION GNSS), Portland, Oregon, Sept. 19-23, 2011, pp. 780-794.

Project Objectives

Porting open-source implementation of GNSS on an embedded platform

Project Implementation Method

It may be broadly dived into the following steps.

1. A literature review of GNSS will be carried out to develop know-how of the system. Different constellations and issues will be studied.
2. The open-source GNSS-SDR platform will be explored, and its architecture will be studied by installing/running it on a Linux-based PC/laptop, in offline mode, on the already captured GNSS raw data.
3. A C/C++ only embedded version will be readied on the embedded platform of Raspberry Pi. Effort will be made to run it with a real GNSS signal.
4. There may be timing-related issues on the C/C++ version. So, the GNSS-SDR will be moved to the Xilinx Zynq SoC kit. The GNSS-SDR will be profiled over that kit. And the compute-intensive parts will be moved to FPGA fabric if required.
5. Effort will be made to run it with a real GNSS signal.

Benefits of the Project

1. Software defined implantation of GNSS may be useful for integration with anti-jamming systems.
2. Performance of the receiver is expected to be better than COTS (commercial off-the-shelf) receiver.
3. User may improve the receiver algorithm easily in a software defined implementation.

Technical Details of Final Deliverable

The final deliverable will be a working software-defined GNSS receiver on an embedded platform providing a position fix comparable to commercial ASIC-based GNSS receivers.

Final Deliverable of the Project Software SystemCore Industry TransportationOther IndustriesCore Technology OthersOther TechnologiesSustainable Development Goals Industry, Innovation and InfrastructureRequired Resources

Item Name	Type	No. of Units	Per Unit Cost (in Rs)	Total (in Rs)
			Total in (Rs)	80000
Xilinx Zynq SoC Kit	Equipment	1	70000	70000
Stationery, Poster, thesis printing	Miscellaneous	1	5000	5000
Overheads, visits fare	Miscellaneous	1	5000	5000