Blind adaptive and iterative algorithms for decision feedback DS-CDMA receivers in dispersive channels

Author

De Lamare, Rodrigo C. ; Sampaio-Neto, Raimundo

Author_Institution

PUC-RIO, Rio de Janeiro

Volume

6

fYear

2005

fDate

2-2 Dec. 2005

Lastpage

3372

Abstract

In this paper we examine blind adaptive and iterative decision feedback (DF) receivers for direct sequence code division multiple access (DS-CDMA) systems in frequency selective channels. Code-constrained minimum variance (CMV) and constant modulus (CCM) design criteria for DF receivers based on constrained optimization techniques are investigated for scenarios subject to multipath. Computationally efficient blind adaptive recursive least squares (RLS) algorithms are developed for estimating the parameters of DF detectors along with successive, parallel and iterative DF structures. A new successive parallel arbitrated DF scheme is presented and combined with iterative techniques for use with cascaded DF stages for mitigating the deleterious effects of error propagation. Simulations for an uplink scenario assess the new blind algorithms, DF structures and the effects of error propagation of the new techniques

Keywords

automatic repeat request; code division multiple access; dispersive channels; least squares approximations; multipath channels; optimisation; spread spectrum communication; blind adaptive algorithms; code-constrained minimum variance; constant modulus design; constrained optimization techniques; decision feedback DS-CDMA receivers; direct sequence code division multiple access; dispersive channels; error propagation; frequency selective channels; iterative algorithms; recursive least squares algorithms; uplink scenario assess; Concurrent computing; Constraint optimization; Design optimization; Direct-sequence code-division multiple access; Dispersion; Feedback; Frequency conversion; Iterative algorithms; Least squares approximation; Multiaccess communication;

fLanguage

English

Publisher

ieee

Conference_Titel

Global Telecommunications Conference, 2005. GLOBECOM '05. IEEE

Conference_Location

St. Louis, MO

Print_ISBN

0-7803-9414-3

Type

conf

DOI

10.1109/GLOCOM.2005.1578398

Filename

1578398