Title :
Low complexity polynomial receivers for downlink CDMA
Author_Institution :
Supelec, Gif-sur-Yvette, France
Abstract :
In downlink CDMA, linear multiuser receivers such as the MMSE receiver are often difficult to implement, especially when the spreading factor is large. A trade-off consists in approximating the inverse of the received signal covariance matrix by a polynomial in this matrix. In this paper, a simple algorithm for computing the coefficients of this polynomial for large spreading factors is proposed. The situation where the channel is frequency selective and the users have possibly different powers is considered. Code matrices are modeled as isometric random matrices or as random matrices with i.i.d. elements and the so called Free Probability theory is used.
Keywords :
3G mobile communication; code division multiple access; covariance matrices; least mean squares methods; matrix inversion; multiuser channels; polynomial matrices; probability; radio links; radio receivers; spread spectrum communication; DS-CDMA system; MMSE receiver; UMTS FDD mode; code matrices; downlink CDMA; free probability theory; frequency selective channel; i. i. d. elements; inverse received signal covariance matrix; isometric random matrices; linear multiuser receivers; low complexity polynomial receivers; polynomial coefficients; spreading factor; Additive noise; Additive white noise; Covariance matrix; Downlink; Interference; Mean square error methods; Microwave filters; Multiaccess communication; Polynomials; Signal to noise ratio;
Conference_Titel :
Signals, Systems and Computers, 2002. Conference Record of the Thirty-Sixth Asilomar Conference on
Conference_Location :
Pacific Grove, CA, USA
Print_ISBN :
0-7803-7576-9
DOI :
10.1109/ACSSC.2002.1197114
