© The Institution of Engineering and Technology
In global positioning system modernisation, a new civil signal namely L2C signal has been broadcast since 2005. Compared with the widely used C/A code signal, although the new signal provides lots of advantages such as better acquisition and tracking performances, the used civil moderate (CM) code and civil long code have much longer periods than C/A code and they make L2C signal acquisition challengeable. Although previous acquisition methods are effective, their computational complexities are still high. To this end, in the study, a composite CM (CCM) code structure is developed by reconstructing the previous return-to-zero CM (RZCM) code through the previous folding technique. Then the CCM code is comprehensively assessed. Compared with the RZCM code, the developed CCM code has following advantages. It can be implemented by small scale FFT block, which is desirable for resource-limited L2C receivers; it is more robust against navigation data and carrier Doppler, and performs more reliable detection performance; for normally received L2C signal, which is usually not <42 dBHz, it spends less time on acquisition. Theoretical and simulation results demonstrate the advantages.
References
-
-
1)
-
17. Proakis, J.G.: ‘Digital communications’ (McGraw-Hill, New York, 2000).
-
2)
-
8. Ta, T.H., Qaisar, S.U., Dempster, A., Dovis, F.: ‘Partial differential postcorrelation processing for GPS L2C signal acquisition’, IEEE Trans. Aerosp. Electron. Syst., 2012, 48, (2), pp. 1287–1305 (doi: 10.1109/TAES.2012.6178062).
-
3)
-
3. Kaplan, E.D., Hegarty, C.J. (eds): ‘Understanding GPS: Principles and applications’ (Artech House, Norwood, 2006).
-
4)
-
16. Simsky, A., Sleewaegen, J.M., Nemry, P., Van Hees, J.: ‘Signal performance and measurement noise assessment of the first L2C signal-in-space’. Proc. IEEE/ION PLANS, 2006, pp. 834–839.
-
5)
-
H. Li ,
X. Cui ,
M. Lu ,
Z. Feng
.
Dual-folding based rapid search method for long PN-code acquisition.
IEEE Trans. Wirel. Commun.
,
12 ,
5286 -
5296
-
6)
-
13. Yang, C., Vasquez, M.J., Chaffee, J.: ‘Fast direct P(Y)-code acquisition using XFAST’. Proc. ION GPS, Nashville, TN, 1999, pp. 317–324.
-
7)
-
1. Fontana, R.D., Cheung, W., Novak, P.M., Stansell, Jr.T.A.: ‘The new L2 civil signal’. Proc. ION GNSS 2001, Salt Lake City, UT, 2001, pp. 617–631.
-
8)
-
15. Kay, S.M.: ‘Fundamentals of statistical signal processing: detection theory’ (Prentice Hall, New Jersey, 1993).
-
9)
-
1. Li, H., Lu, M., Feng, Z.: ‘Partial-correlation-result reconstruction technique for weak global navigation satellite system long pseudo-noise-code acquisition’, IET Radar Sonar Navig., 2011, 5, (7), pp. 731–740 (doi: 10.1049/iet-rsn.2010.0321).
-
10)
-
10. Qaisar, S.U.: ‘Receiver strategies for GPS L2C signal processing’. PhD thesis, The University of New South Wales, 2010.
-
11)
-
9. Qaisar, S.U., Dempster, A.G.: ‘Assessment of the GPS L2C code structure for efficient signal acquisition’, IEEE Trans. Aerosp. Electron. Syst., 2012, 48, (3), pp. 1889–1902 (doi: 10.1109/TAES.2012.6237568).
-
12)
-
2. Tran, M., Hegarty, C.: ‘Performance evaluations of the new GPS L5 and L2 civil signals’. Proc. ION NTM 2003, Anaheim, CA, USA, 2003, pp. 521–535.
-
13)
-
7. Gernot, C., O'Keefe, K., Lachapelle, G.: ‘Assessing three new GPS combined L1/L2C acquisition methods’, IEEE Trans. Aerosp. Electron. Syst., 2011, 47, (3), pp. 2239–2247 (doi: 10.1109/TAES.2011.5937297).
-
14)
-
4. Psiaki, M.L.: ‘FFT-based acquisition of GPS L2 civilian CM and CL signals’. Proc. ION GNSS 2004, Long Beach, CA, USA, 2004, pp. 457–472.
-
15)
-
6. Dempster, A.: ‘Correlators for L2C: some considerations’. InsideGNSS, October 2006, pp. 32–37.
-
16)
-
5. Yang, C.: ‘Joint acquisition of CM and CL codes for GPS L2 civil (L2C) signals’. Proc. ION AM 2005, Cambridge, MA, June 2005, pp. 553–562.
-
17)
-
11. Moghaddam, A.R., Watson, R., Lachapelle, G., Nielsen, J.: ‘Exploiting the orthogonality of L2C code delays for a fast acquisition’. Proc. ION ITM, Fort Worth TX, 2006, pp. 1233–1241.
http://iet.metastore.ingenta.com/content/journals/10.1049/iet-rsn.2014.0479
Related content
content/journals/10.1049/iet-rsn.2014.0479
pub_keyword,iet_inspecKeyword,pub_concept
6
6