论文信息 - Averaged stochastic gradient algorithms for adaptive blind multiuser detection in DS/CDMA systems

Averaged stochastic gradient algorithms for adaptive blind multiuser detection in DS/CDMA systems

In this paper, we present a blind adaptive gradient (BAG) algorithm for code-aided suppression of multiple-access interference (MAI) and narrow-band interference (NBI) in direct-sequence/code-division multiple-access (DS/CDMA) systems. This BAG algorithm is based on the concept of accelerating the convergence of a stochastic gradient algorithm by averaging. This ingenious concept of averaging was invented by Polyak and Juditsky (1992)-this paper examines its application to blind multiuser detection and NBI suppression in DS/CDMA systems. We prove that BAG has identical convergence and tracking properties to recursive least squares (LMS) but has a computational cost similar to the least mean squares (LMS) algorithm-i.e., an order of magnitude lower computational cost than RLS. Simulations are used to compare our averaged gradient algorithm with the blind LMS and LMS schemes.

Vikram Krishnamurthy

[1] Vikram Krishnamurthy,et al. Averaging methods for blind multiuser detection in DS/CDMA systems , 1998, IEEE GLOBECOM 1998 (Cat. NO. 98CH36250).

[2] H. White. Asymptotic theory for econometricians , 1985 .

[3] Simon Haykin,et al. Adaptive filter theory (2nd ed.) , 1991 .

[4] Harold J. Kushner,et al. Stochastic Approximation Algorithms and Applications , 1997, Applications of Mathematics.

[5] G. Yin,et al. Averaging procedures in adaptive filtering: an efficient approach , 1992 .

[6] Boris Polyak,et al. Acceleration of stochastic approximation by averaging , 1992 .

[7] Vikram Krishnamurthy,et al. Adaptive nonlinear filters for narrow-band interference suppression in spread-spectrum CDMA systems , 1999, IEEE Trans. Commun..

[8] H. Kushner,et al. Stochastic approximation with averaging of the iterates: Optimal asymptotic rate of convergence for , 1993 .

[9] Upamanyu Madhow,et al. Blind adaptive multiuser detection , 1995, IEEE Trans. Inf. Theory.

[10] H. Vincent Poor,et al. Code-aided interference suppression for DS/CDMA communications. II. Parallel blind adaptive implementations , 1997, IEEE Trans. Commun..

[11] Lennart Ljung,et al. Adaptation and tracking in system identification - A survey , 1990, Autom..

[12] Lennart Ljung,et al. Aspects on accelerated convergence in stochastic approximation schemes , 1994, Proceedings of 1994 33rd IEEE Conference on Decision and Control.