Title :
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
fDate :
12/1/1999 12:00:00 AM
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;
Journal_Title :
Selected Areas in Communications, IEEE Journal on
