Interference Excision in Spread Spectrum Communications Using Adaptive Positive Time-Frequency Analysis
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This paper introduces a novel algorithm to excise single and multicomponent chirp-like interferences in direct sequence spread spectrum (DSSS) communications. The excision algorithm consists of two stages: adaptive signal decomposition stage and directional element detection stage based on the Hough-Radon transform (HRT). Initially, the received spread spectrum signal is decomposed into its time-frequency (TF) functions using an adaptive signal decomposition algorithm, and the resulting TF functions are mapped onto the TF plane. We then use a line detection algorithm based on the HRT that operates on the image of the TF plane and detects energy varying directional elements that satisfy a parametric constraint. Interference is modeled by reconstructing the corresponding TF functions detected by the HRT, and subtracted from the received signal. The proposed technique has two main advantages: (i) it localizes the interferences on the TF plane with no cross-terms, thus facilitating simple filtering techniques based on thresholding of the TF functions, and is an efficient way to excise the interference; (ii) it can be used for the detection of any directional interferences that can be parameterized. Simulation results with synthetic models have shown successful performance with linear and quadratic chirp interferences for single and multicomponent interference cases. The proposed method excises the interference even under very low SNR conditions of Open image in new window dB, and the technique could be easily extended to any interferences that could be represented by a parametric equation in the TF plane.
KeywordsLine Detection Detection Stage Directional Interference Direct Sequence Spread Spectrum Spread Spectrum Communication
- 3.Poor HV, Wang X: Adaptive suppression of narrowband digital interferers from spread spectrum signals. Proceedings of IEEE International Conference on Acoustics, Speech, and Signal Processing (ICASSP '96), May 1996, Atlanta, Ga, USA 2: 1061-1064.Google Scholar
- 4.Liu L, Ge H: Time-varying AR modeling and subspace projection for FM jammer suppression in DS/SS-CDMA systems. Proceedings of the 37th Asilomar Conference on Signals, Systems and Computers (ACSSC '03), November 2003, Pacific Grove, Calif, USA 1: 623-627.Google Scholar
- 10.Krongold BS, Kramer ML, Ramchandran K, Jones DL: Spread spectrum interference suppression using adaptive time-frequency tilings. Proceedings of IEEE International Conference on Acoustics, Speech, and Signal Processing (ICASSP '97), April 1997, Munich, Germany 3: 1881-1884.Google Scholar
- 12.Bultan A, Akansu AN: A novel time-frequency exciser in spread spectrum communications for chirp-like interference. Proceedings of IEEE International Conference on Acoustics, Speech, and Signal Processing (ICASSP '98), May 1998, Seattle, Wash, USA 6: 3265-3268.Google Scholar
- 13.Suleesathira R, Chaparro LF: Jammer excision in spread spectrum using discrete evolutionary-Hough transform and singular value decomposition. Proceedings of the 10th IEEE Signal Processing Workshop on Statistical Signal and Array Processing (SSAP '00), August 2000, Pennsylvania, Pa, USA 519-523.Google Scholar
- 15.Matz G, Hlawatsch F: Time-frequency projection filters: online implementation, subspace tracking, and application to interference excision. Proceedings of IEEE International Conference on Acoustics, Speech, and Signal Processing (ICASSP '02), May 2002, Orlando, Fla, USA 2: 1213-1216.Google Scholar
- 16.Amin MG, Mandapati GR: Nonstationary interference excision in spread spectrum communications using projection filtering methods. Proceedings of the 32nd Asilomar Conference on Signals, Systems and Computers, November 1998, Pacific Grove, Calif, USA 1: 827-831.Google Scholar
- 17.Krishnan S: Adaptive signal processing techniques for analysis of knee joint vibroarthrographic signals, Ph.D. thesis. University of Calgary, Alberta, Canada; 1999.Google Scholar
- 21.Erkucuk S, Krishnan S: Time-frequency filtering of interferences in spread spectrum communications. Proceedings of the 7th International Symposium on Signal Processing and Its Applications (ISSPA '03), July 2003, Paris, France 2: 323-326.Google Scholar
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