Nonlinear multiuser parameter estimation and tracking in CDMA systems

Author

Caffery, James ; Stüber, Gordon L.

Author_Institution

Dept. of Electr. & Comput. Eng., Cincinnati Univ., OH, USA

Volume

48

Issue

12

fYear

2000

fDate

12/1/2000 12:00:00 AM

Firstpage

2053

Lastpage

2063

Abstract

This paper presents a joint channel coefficient and time-delay tracking technique for code-division multiple-access (CDMA) systems. Due to the highly nonlinear nature of time delay estimation, an iterative nonlinear filtering algorithm, called the “unscented filter” (UF), is employed. The UF can provide a better alternative to nonlinear filtering than the conventional extended Kalman filter (EKF) since it avoids errors associated with linearization. The Cramer-Rao lower bound is derived for the estimator, and computer simulations show that it provides a more viable means for tracking time-varying amplitudes and delays in CDMA communication systems than estimators based on the EKF

Keywords

cellular radio; code division multiple access; filtering theory; iterative methods; multiuser channels; nonlinear estimation; nonlinear filters; parameter estimation; personal communication networks; radio tracking; spread spectrum communication; CDMA systems; Cramer-Rao lower bound; DS-CDMA; PCS systems; cellular radio systems; channel coefficient tracking; code-division multiple-access; computer simulations; extended Kalman filter; iterative nonlinear filtering algorithm; nonlinear multiuser parameter estimation; time delay estimation; time-delay tracking; time-varying amplitude tracking; time-varying delay tracking; unscented filter; Amplitude estimation; Computer errors; Delay effects; Delay estimation; Detectors; Filtering algorithms; Frequency; Multiaccess communication; Multiple access interference; Parameter estimation;

fLanguage

English

Journal_Title

Communications, IEEE Transactions on

Publisher

ieee

ISSN

0090-6778

Type

jour

DOI

10.1109/26.891216

Filename

891216