Title :
Bounds for the MSE performance of constant modulus estimators
Author :
Schniter, Philip ; Johnson, C. Richard, Jr.
Author_Institution :
Dept. of Electr. Eng., Ohio State Univ., Columbus, OH, USA
fDate :
11/1/2000 12:00:00 AM
Abstract :
The constant modulus (CM) criterion has become popular in the design of blind linear estimators of sub-Gaussian independent and identically distributed (i.i.d.) processes transmitted through unknown linear channels in the presence of unknown additive interference. In this paper, we present an upper bound for the conditionally unbiased mean-squared error (UMSE) of CM-minimizing estimators that depends only on the source kurtoses and the UMSE of Wiener estimators. Further analysis reveals that the extra UMSE of CM estimators can be upper-bounded by approximately the square of the Wiener (i.e., minimum) UMSE. Since our results hold for vector-valued finite-impulse response/infinite-impulse response (FIR/IIR) linear channels, vector-valued FIR/IIR estimators with a possibly constrained number of adjustable parameters, and multiple interferers with arbitrary distribution, they confirm the longstanding conjecture regarding the general mean-square error (MSE) robustness of CM estimators
Keywords :
FIR filters; IIR filters; array signal processing; blind equalisers; deconvolution; estimation theory; interference (signal); least mean squares methods; multiuser channels; signal detection; CM-minimizing estimators; MSE performance; UMSE; Wiener estimators; adjustable parameters; blind linear estimators; conditionally unbiased mean-squared error; constant modulus criterion; constant modulus estimators; i.i.d. processes; linear channels; multiple interferers; source kurtoses; sub-Gaussian independent and identically distributed processes; unknown additive interference; vector-valued FIR estimators; vector-valued IIR estimators; vector-valued finite-impulse response linear channels; vector-valued infinite-impulse response linear channels; AWGN; Array signal processing; Blind equalizers; Delay estimation; Finite impulse response filter; Interference constraints; Robustness; Statistics; Upper bound; Vectors;
Journal_Title :
Information Theory, IEEE Transactions on
