Theory and Application of Adaptive Transmission Radar

Joseph R. Guerci
3701 N. Fairfax Drive
Arlington, VA 22203
S. Unnikrishna Pillai
Polytechnic University
6 MetroTech Center
Brooklyn, NY 11201

Abstract Recent advances in linear amplifier and arbitrary waveform generation technology have spawned interest in adaptive transmitter systems as a means for both combating lectronic attack, optimizing target signal gain and enhancing ID. In this paper, rigorous theoretical performance bounds are constructively established for the joint transmitter-target-channel-receiver optimization problem in the presence of both additive colored noise (ACN), (e.g., interference multipath) and signal dependent noise (ASDN) (e.g., clutter) [1]-[3]. For the ACN case, an analytical solution is obtained as an eigenvector (with associated maximum eigenvalue) of a homogeneous Fredholm integral equation of the second type (i.e., an eigensystem). The kernel function is Hermitian and is obtained from the cascade of the target impulse response with the ACN whitening filter. For the ASDN case, the problem becomes nonlinear in general. However, an alternating-projection-like iteration has been developed which has been found to be rapidly convergent [2]-[3]. In all cases it is established that any optimal waveform has a minimum phase property. The theoretical performance gains achievable over conventional transmitter strategies (e.g., chirp) are presented for various high-fidelity simulation scenarios including interference multipath mitigation and clutter. Also discussed, is the potential effectiveness of an optimal discriminating pulse solution for N-target ID problem that arises naturally from the theory.

[1] J. R. Guerci, et al.,  US Patents: 5121125, 5146229, 5381154, 5392050.

[2] "Optimum Transmit-Receiver Design in the Presence of Signal-Dependent Interference and Channel Noise," S. U. Pillai, D. C. Youla, H. S. Oh, and J. R. Guerci, Proceedings of the 33rd Asilomar Conference on Signals, Systems, and Computers,  October 24-27, Pacific Grove, CA 1999.

[3] "Matched Transmit-Receiver Design in the Presence of Signal Dependent Noise,"   S. U. Pillai, D. C. Youla, H. S. Oh, and J. R. Guerci, IEEE Transactions on Information Theory, to appear, March 2000.

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