Nonlinear RLS algorithm for impulsive CDMA channels

Bayan S Sharif; Teong Chee Chuah; Oliver R Hinton; Shihab A Jimaa

doi:10.1117/12.511930

8 August 2003 Nonlinear RLS algorithm for impulsive CDMA channels

Bayan S Sharif, Teong Chee Chuah, Oliver R Hinton, Shihab A Jimaa

Proceedings Volume 5245, Internet Quality of Service; (2003) https://doi.org/10.1117/12.511930
Event: ITCom 2003, 2003, Orlando, Florida, United States

Abstract

Multiuser detection constitutes a class of advanced interference mitigation techniques for increasing the capacity of CDMA communication systems. Thus far, the work has been carried out under the Gaussian noise assumption for analytical convenience and yet physical noise encountered in real-life channels is impulsive and decidedly non-Gaussian. Since Gaussian signal processing schemes can perform poorly in impulsive noise, the applicability and performance of such multiuser detectors in realistic channels become strongly questionable. This paper addresses the development of non-Gaussian techniques for CDMA communications, by first examining the performance degradation of Linear Gaussian-based multiuser detectors in impulsive noise and then by presenting a series of nonlinear techniques to yield a more robust performance. A common approach to linear adaptive interference suppression in Direct Sequence CDMA is based on the Least Mean Square (LMS) or Recursive Least Square (RLS) algorithms to capture the cyclo-stationarity of multiple access interference (MAI) adaptively, mostly under the minimum mean squared error (MMSE) criterion. However, under impulsive noise environments, the performance of the conventional RLS algorithm deteriorates substantially, and therefore, a robust algorithm based on nonlinear RLS is suggested to obtain a modified CDMA receiver structure. Simulation results are presented to demonstrate that the proposed modified nonlinear RLS algorithm significantly outperforms the conventional RLS algorithm whilst it maintains comparable performance in Gaussian channels.

Citation Download Citation

Bayan S Sharif, Teong Chee Chuah, Oliver R Hinton, and Shihab A Jimaa "Nonlinear RLS algorithm for impulsive CDMA channels", Proc. SPIE 5245, Internet Quality of Service, (8 August 2003); https://doi.org/10.1117/12.511930

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available