New nonlinear algorithms for narrowband interference suppression in CDMA spread-spectrum systems

Author

Wang, Kun-Jie ; Yao, Yan

Author_Institution

Dept. of Electron. Eng., Tsinghua Univ., Beijing, China

Volume

17

Issue

12

fYear

1999

fDate

12/1/1999 12:00:00 AM

Firstpage

2148

Lastpage

2153

Abstract

The narrow-band interference suppression capability of spread-spectrum systems can be further enhanced by employing interference suppression filters. This paper proposes a number of new nonlinear algorithms for narrow-band interference suppression in code division multiple access spread-spectrum systems. Our research consists of two parts. (1) We propose a multiuser decision-directed Kalman (MDK) filter, which has the same performance as the nonlinear approximate conditional mean (ACM) filter but a much simpler algorithm. (2) We use the nonlinear function in the ACM and the MDK filters to develop nonlinear adaptive least mean square filters with significantly improved performance. Simulation results indicate that our nonlinear algorithms outperform conventional linear ones

Keywords

adaptive Kalman filters; adaptive signal processing; code division multiple access; filtering theory; interference suppression; least mean squares methods; nonlinear filters; nonlinear functions; radiofrequency interference; spread spectrum communication; CDMA spread-spectrum systems; code division multiple access; interference suppression filters; linear algorithms; multiuser decision-directed Kalman filter; narrowband interference suppression; nonlinear adaptive least mean square filters; nonlinear algorithms; nonlinear approximate conditional mean filter; nonlinear function; performance; simulation results; Adaptive algorithm; Adaptive filters; Interference suppression; Kalman filters; Least squares approximation; Multiaccess communication; Narrowband; Nonlinear filters; Spread spectrum communication; Statistics;

fLanguage

English

Journal_Title

Selected Areas in Communications, IEEE Journal on

Publisher

ieee

ISSN

0733-8716

Type

jour

DOI

10.1109/49.814831

Filename

814831