GPS Solutions

, Volume 14, Issue 2, pp 133–139 | Cite as

An enhanced bit-wise parallel algorithm for real-time GPS software receiver

  • Jiangping DengEmail author
  • Ruizhi Chen
  • Jianyu Wang
Original Article


Software-based global positioning system (GPS) receivers perform all the baseband signal processing and the high level functions on a general purpose processor. The heavy computational loads of the signal correlation in baseband processing make it difficult for software receivers to operate in real time. In order to improve the real-time performance, an enhanced bit-wise parallel algorithm has been developed in this study. The enhanced algorithm has been implemented and tested in a 12 channels real-time GPS software receiver. The system consists of a radio frequency front end, a data acquisition board and software that runs on a laptop with a Pentium-M 1.5 GHz processor running the Window® XP operating system. The data acquisition board packs the 2-bit intermediate frequency samples with a 2-bit in/8-bit out shift register and transfers the packed samples to laptop through a USB port. The software running on the laptop performs all the baseband and navigation processing in real time. The test results show that the enhanced algorithm significantly improves the real-time performance of the software receiver by reducing the computational operations for signal correlation by 50% compared with the existing bit-wise parallel algorithm. Furthermore, the enhanced algorithm also reduces the amount of required memory for storing data for signal correlation.


Real time Software receiver Enhanced bit-wise parallel algorithm 


  1. Bao J, Tsui Y (2000) Fundamentals of global positioning system receivers: a software approach. Wiley, New YorkGoogle Scholar
  2. Charkhandeh S, Petovello MG, Lachapelle G (2006) Performance testing of a real-time software-based GPS receiver for x86 processors. In: Proceedings of the 19th international technical meeting of the satellite division, ION GNSS, Fort Worth, pp 2313–2320Google Scholar
  3. Cho DJ, Won Lim D, Park C, Lee SJ (2006) An efficient signal processing scheme using signal compression for software GPS receivers. Int J Control Autom Syst 4(3):344–350Google Scholar
  4. Heckler GW, Garrison JL (2004) Architecture of a reconfigurable software receiver. In: Proceedings of the 17th international technical meeting, ION GNSS, Long Beach, pp 947–955Google Scholar
  5. Ledvina BM, Powell SP, Kintner PM et al (2003a) A 12-channel real-time GPS L1 software receiver. In: Proceedings of the 2003 national technical meeting, ION, Anaheim, pp 762–782Google Scholar
  6. Ledvina BM, Cerruti AP, Psiaki M L et al (2003b) Performance tests of a 12-channel real-time GPS L1 software receiver. In Proceedings of the 16th international technical meeting of the satellite division, ION GNSS, Portland, pp 679–688Google Scholar
  7. Ledvina BM, Psiaki ML, Powell SP, Kintner P (2004) Bit-wise parallel algorithms for efficient software correlation applied to a GPS software receiver. IEEE Trans Wirel Comm 3(5):1469–1473. doi: 10.1109/TWC.2004.833467 CrossRefGoogle Scholar
  8. Petovello MG, Lachapelle G (2006) An efficient new method of Doppler removal and correlation with application to software-based GNSS receivers. In: Proceedings of international technical meeting of the satellite division, ION GNSS, Fort Worth, pp 2407–2417Google Scholar
  9. Van Dierendonck AJ (1996) GPS receivers. In: Parkinson BW, Spilker JJ Jr (eds) Global positioning system: theory and applications, vol 1. American Institute of Aeronautics and Astronautics, Washington, pp 329–407Google Scholar

Copyright information

© Springer-Verlag 2009

Authors and Affiliations

  1. 1.Shanghai Institute of Technical PhysicsChinese Academy of SciencesShanghaiChina
  2. 2.Department of Navigation and PositioningFinnish Geodetic InstituteMasalaFinland

Personalised recommendations