Algorithm for Suppression of Wideband Probing in Adaptive Array with Multiple Desired Signals

  • Hema Singh National Aerospace Laboratories, Bengaluru
  • R. M. Jha National Aerospace Laboratories, Bengaluru
Keywords: Adaptive antenna array, desired signals, improved LMS algorithm, probing source, suppression

Abstract

The integrity of signal environment for a navigation system among other factors depends critically on the capability of the adaptive antenna array in controlling (reconfiguring) its radiation pattern for various signal scenarios. For a signal environment consisting of simultaneous multiple desired signals and probing sources, the output signal-to-noise ratio of the adaptive antenna array depends on the efficiency of the adaptive algorithm employed for weight estimation. Sufficient antenna gain is required to be maintained towards each of the desired signals, while simultaneously suppressing returns towards the sources probing from distinctly different directions. The weight estimation for the multiple desired signal environments is carried out using a novel modified version of the improved least mean square (LMS) algorithm. This modified scheme effectively suppresses the narrowband/wideband probing towards the antenna array (linear/planar). The weight estimation and the steering vector are adapted according to the multiple desired signal environments. Each spectral line of the wideband source is considered as an independent narrowband source. This is incorporated in the correlation matrix of the received signal. The simulation results demonstrate the efficacy of this novel algorithm in active cancellation of narrowband/wideband probing sources, even while the simultaneous multiple signals in desired directions are maintained. The performance of the proposed algorithm is reported to be better than that of standard LMS and recursive LMS algorithm.

Defence Science Journal, 2011, 61(4), pp.325-330, DOI:http://dx.doi.org/10.14429/dsj.61.1092

Author Biographies

Hema Singh, National Aerospace Laboratories, Bengaluru
Dr Hema Singh received her PhD (Electronics Engineering) from Institute of Technology (IT-BHU), Banaras Hindu University, Varanasi, in 2000. She is working as Scientist in Computational Electromagnetics Laboratory, National Aerospace Laboratories (CSIR-NAL), Bengaluru. Her active areas of research interests are: Computational electromagnetics (CEM) for aerospace applications, GTD/UTD, EM analysis of indoor environment, phased arrays, radar cross section (RCS) studies including active RCS reduction. She has published 85 scientific research papers and technical reports. She has also supervised over 22 graduate projects and postgraduate dissertations.
R. M. Jha, National Aerospace Laboratories, Bengaluru
Dr Rakesh Mohan Jha obtained MSc (Physics) in 1982 from BITS, Pilani, and PhD (Engg.) in 1989 from Department of Aerospace Engineering, Indian Institute of Science, Bengaluru. He is currently working as Scientist G and Group Head, Computational Electromagnetics Laboratory, National Aerospace Laboratories, Bengaluru. He is also concurrently an Adjunct Professor of BITS, Pilani, and an Associate Dean of the Academy of Scientific and Innovative Research (AcSIR) New Delhi since 2010. His active areas of research are in the domain of: Computational electromagnetics (CEM) for aerospace applications. These include: GTD/UTD, 3-D ray tracing and surface modelling, aerospace antennas and radomes, radar cross section (RCS) studies including active RCS reduction, radar absorbing materials and radar absorbing structures, and metamaterials for aerospace applications. He has published more than three hundred scientific research papers and technical reports. He was awarded Sir CV Raman Award for Aerospace Engineering for the Year 1999. He is a Fellow of Indian National Academy of Engineering (FNAE).
Published
2011-07-18
How to Cite
SinghH., & JhaR. (2011). Algorithm for Suppression of Wideband Probing in Adaptive Array with Multiple Desired Signals. Defence Science Journal, 61(4), 325-330. https://doi.org/10.14429/dsj.61.1092