Title :
Steady-state analysis of the multistage constant modulus array
Author :
Shynk, John J. ; Keerthi, Arvind V. ; Mathur, Amit
Author_Institution :
Dept. of Electr. & Comput. Eng., California Univ., Santa Barbara, CA, USA
fDate :
4/1/1996 12:00:00 AM
Abstract :
The multistage constant modulus (CM) array is a cascade adaptive beamforming system that can recover several narrowband cochannel signals without training. We examine its steady-state properties at convergence using a stochastic analysis and computer simulations. Based on a Wiener model of convergence for the gradient adaptive algorithms, closed-form expressions are derived for the CM array and canceller weight vectors, as well as the effective source direction vectors at all stages along the cascade system. The signal-capture and direction-finding capabilities of the system are also discussed. Computer simulations for stationary and fading sources are presented to confirm the theoretical results and to illustrate the rapid convergence behavior of the adaptive algorithms
Keywords :
array signal processing; cochannel interference; convergence of numerical methods; fading; interference suppression; matrix algebra; stochastic processes; Wiener model; adaptive algorithms; array matrix; array weight vectors; canceller weight vectors; cascade adaptive beamforming system; closed form expressions; cochannel interference; computer simulations; convergence; direction finding; fading sources; gradient adaptive algorithms; multistage constant modulus array; narrowband cochannel signals recovery; signal capture; source direction vectors; stationary sources; steady state analysis; steady state properties; stochastic analysis; Adaptive algorithm; Adaptive arrays; Adaptive systems; Array signal processing; Closed-form solution; Computer simulation; Convergence; Narrowband; Steady-state; Stochastic processes;
Journal_Title :
Signal Processing, IEEE Transactions on