Development of a Versatile Groundstation Utilizing Software Defined Radio
Abstract
As software defined systems establish modern technology, the Space Systems Academic Group (SSAG) of the Naval Postgraduate
School (NPS) is compelled to replace legacy hardware systems with inexpensive and flexible software defined
solutions. One key aspect in ensuring stable communication with the multiple small satellites and CubeSats launched
by the SSAG, is to develop and maintain a versatile satellite groundstation utilizing inexpensive off-the-shelf Software
Defined Radio (SDR). This thesis presents the demodulation and decoding of a 1200 baud AFSK signal from a BigRed-
Bee, as well as a 9600 baud GFSK signal from a PropCube CubeSat. The demodulating signal processing steps are designed
in GNU Radio Companion. The thesis also deals with parts of the AX.25 data link layer protocol decoding. Bit-per-bit
comparison of the outputs in performed tests show that the SDR can replace the currently used software. A bit error
rate (BER) calculation proves the excellent performance of the GFSK demodulation scheme. The performed BER test
results in a BER < 1 × 10⁻⁴ for a SNR of E(b)/N(0) = 6dB, whereas the estimated BER for a coherent MSK signal is
BER(MSK) ≈ 2×10⁻⁴ for the same SNR. Additionally, this thesis presents one option of a real-time implementation of
the PropCube Receiver. This thesis also provides test results of performed function tests, subsystem tests and integrated
system tests, accompanied by in depth explanations on the settings and preferences of each used GNU Radio block.
Rights
Copyright is reserved by the copyright ownerNPS Report Number
NPS-SP-16-003 CRRelated items
Showing items related by title, author, creator and subject.
-
Cost estimation of post production software support in ground combat systems
Cannon, Christopher J. (Monterey, California. Naval Postgraduate School, 2007-09);Weapon systems and programs are becoming increasingly more dependent on software as a critical technology for the success of the programs. Along with this dependence on performance, the costs associated with software are ... -
Deriving the Cost of Software Maintenance for Software Intensive Systems
Sams, Bradley J. (Monterey, California. Naval Postgraduate School, 2011-08-29); NPS-CE-11-160Throughout software''s lifetime, changes are introduced to the code in order to maintain the desired performance. These changes often create side effects, which cause other cascading effects elsewhere in the software or ... -
Agile and Lean Systems Engineering: Kanban in Systems Engineering
Turner, Richard; Madachy, Ray; Lane, Jo Ann; Ingold, Dan; Levine, Laurence (SERC, 2013-03-06); SERC-2013-TR-022-2This is the 2nd of two reports that were created for research on this topic funded through SERC. The first report, SERC-TR-032-1 dated March 13, 2012, constituted the 2011-2012 Annual Technical Report and the Final Technical ...