Cross Correlation Mitigation by Adaptive Orthogonalization Using Constraints - New Results

E. P. Glennon, A.G. Dempster

Abstract:	Many spread spectrum systems that employ Direct Sequence/Code Division Multiple Access (DS/CDMA) techniques suffer from cross correlation or ‘Near-Far’ problems if the spreading codes have a relatively short length, as is the case for CDMA cellular communications and C/A code GPS receivers. One class of methods available for cross correlation mitigation (CCM) includes Subspace Projection, although such methods have typically not been employed due to computational complexity. This paper describes a sub-optimal subspace projection approach to CCM that uses constraints to construct despreading codes that are exactly orthogonal to signals being received by the GPS receiver. Application of the technique using a software GPS correlator written in C and run within a Matlab environment are described and results presented based on realistic datasets acquired using hardware GPS simulators. The effectiveness of the method compared to other more traditional CCM methods is also discussed.
Published in:	Proceedings of the 19th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS 2006) September 26 - 29, 2006 Fort Worth Convention Center Fort Worth, TX
Pages:	1811 - 1820
Cite this article:	Glennon, E. P., Dempster, A.G., "Cross Correlation Mitigation by Adaptive Orthogonalization Using Constraints - New Results," Proceedings of the 19th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS 2006), Fort Worth, TX, September 2006, pp. 1811-1820.
Full Paper:	ION Members/Non-Members: 1 Download Credit Sign In