Multistage MMSE weighted decision feedback multiuser detector for DS-CDMA and MC-CDMA

Author

Hsu, Chen-Chu ; Lee, Yumin

Author_Institution

Dept. of Electr. Eng., Nat. Taiwan Univ., Taipei, Taiwan

Volume

4

fYear

2003

fDate

6-9 Oct. 2003

Firstpage

2421

Abstract

This paper proposes the MMSE weighted decision feedback (WDF) multiuser detector (MUD), which is an enhancement of the MMSE decision-feedback MUD. In contrast to MMSE-DF MUD, in MMSE-WDF past decisions are scaled by weighting factors that reflect their reliability. Furthermore, a multistage structure is utilized to improve the decision quality. An algorithm is also presented for jointly optimizing the reliability weighting factors and the coefficients of feedforward and feedback filters for every stage. Simulation results show that some variations of MMSE-WDF perform very closely to the single-user bound for E_b/N₀ lower than 25 dB and the number of active users less than 30.

Keywords

channel bank filters; code division multiple access; fading channels; least mean squares methods; matrix algebra; multiuser detection; spread spectrum communication; DS-CDMA; MC-CDMA; MMSE weighted decision feedback; MUD; WDF; direct-sequence code division multiple access; feedback filter; feedforward filter; multicarrier CDMA; multistage structure; multiuser detector; Detectors; Feedback; Interference cancellation; Multiaccess communication; Multicarrier code division multiple access; Multiple access interference; Multiuser detection; Signal processing algorithms; Silicon carbide; Spread spectrum communication;

fLanguage

English

Publisher

ieee

Conference_Titel

Vehicular Technology Conference, 2003. VTC 2003-Fall. 2003 IEEE 58th

ISSN

1090-3038

Print_ISBN

0-7803-7954-3

Type

conf

DOI

10.1109/VETECF.2003.1285964

Filename

1285964