Sub-Optimum Detector Based on Reverbertion-Whiten in FrFT Field

Abstract:

Target detection in the presence of strong seabed reverberation is a hot research topic nowadays. This kind of target detection method is similar to signal detection with known shape and unknown parameters under non-WGN or coherent signal detection in reverberation. When a LFM signal is choose as transmitted signal, target echo has excellent time-frequency focusing property on a certain rotating angle and reverberation could lose its original linear modulation property. LFM signal can be transformed to a sine signal with some rank FrFT. Since FrFT is a linear transform, interference including reverberation and noise will keep former statistic characteristics. So LFM signal detection is thus equivalent to detection of sine signals in absence of colored noise. The reverberation will be easily erased and target echo will be preserved. Based on the analysis above all, a sub-optimum detector based on reverberation-whiten in FrFT field is advanced. The validity of these conclusions is validated by computer simulations. A satisfying result is achieved.

• Periodical: Applied Mechanics and Materials (Volume 577)
• Pages: 810-815
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.577.810
• Online since: July 2014
• Authors: Zhen Gang Li*
• Keywords: Chirp, FRFT, Reverberation, Signal Process

References

[1] Carmillet P O, and Amblard G J, Detection of phase or frequency modulated signals in reverberation noise,. JASA, 1999, vol. 6, pp.3375-3389.

DOI: 10.1121/1.424666

[2] Sergio B, and Alfonso F, Space-time-frequency processing of synthetic aperture sonar signals, ". Proc. of IEEE AES, 93, 1994, vol. 2, pp.341-358.

[3] Thomas A P, and Donald W T, Reververation characterization and suppression by means fo principal components, ". OCEANS, 98 Conf. Proceedings, 1998, vol. 3, pp.1501-1506.

[4] Ginolhac G, and Jourdain G, Detection in presence of reverberation,. IEEE OCEANS 2000 MTS, 2000, vol. 2, pp.1043-1046.

DOI: 10.1109/oceans.2000.881738

[5] Namias V. The fractional order Fourier transform and its applications to quantum mechanics, Journal of Institute Applied Math. 1980, vol. 25, pp.241-265.

DOI: 10.1093/imamat/25.3.241

[6] Cianfranco C A. Unified framework for the fractional Fourier transform, IEEE Trans. On Signal Processing. 1998, vol. 46, pp.3206-3219.

DOI: 10.1109/78.735297

[7] Ozaktas H M, and B Brashan, Convolution, filtering and multiplexing in fractional domains and their relation to chirp and wavelet transforms, Journal of Optical Society America(A). 1993, vol. 11, pp.547-559.

DOI: 10.1364/josaa.11.000547

[8] Kay S, and Salisbury S, Improved active sonar detection using autoregressive prewhiteners , JASA, 1990, vol. 4, pp.1603-1611.

DOI: 10.1121/1.399408

[9] Peleg S, and Poral B, The Cramer-Rao Lower Bounds for Signals with Constant Amplitude and polynomial Phase, IEEE Trans. On SP. 1991, vol. 39, pp.979-993.

DOI: 10.1109/78.80864

[10] Candan C, and Kutay M A, The discrete fractional Fourier transform, IEEE Trans. On Signal Processing. 2000, vol. 48, pp.1329-1337.

DOI: 10.1109/78.839980