Title :
Misadjustment and tracking analysis of the constant modulus array
Author :
Keerthi, Arvind V. ; Mathur, Amit ; Shynk, John J.
Author_Institution :
Dept. of Electr. & Comput. Eng., California Univ., Santa Barbara, CA, USA
fDate :
1/1/1998 12:00:00 AM
Abstract :
The constant modulus (CM) array is a blind adaptive beamformer that can separate cochannel signals. A follow-on adaptive signal canceler may be used to perform direction finding of the source captured by the array. In this paper, we analyze the convergence and tracking properties of the CM array using a least-mean-square approximation. Expressions are derived for the misadjustment of the adaptive algorithms, and a tracking model is developed that accurately predicts the behavior of the system during fades. It is demonstrated that the adaptive canceler contributes more to the overall misadjustment than does the adaptive CM beamformer. Computer simulations are presented to illustrate the transient properties of the system and to verify the analytical results
Keywords :
adaptive antenna arrays; adaptive signal processing; array signal processing; cochannel interference; convergence of numerical methods; direction-of-arrival estimation; interference suppression; least mean squares methods; tracking; CM array; adaptive algorithms; adaptive canceler; blind adaptive beamformer; cochannel signals; constant modulus array; convergence; direction finding; fades; follow-on adaptive signal canceler; least-mean-square approximation; misadjustment; tracking analysis; transient properties; Adaptive algorithm; Adaptive arrays; Computer simulation; Convergence; Interchannel interference; Least squares approximation; Predictive models; Signal analysis; Signal processing algorithms; Steady-state;
Journal_Title :
Signal Processing, IEEE Transactions on
