A novel ML combining RAKE receiver for DS-CDMA

Author

Wu, Zhiqiang ; Nassar, Carl R. ; Lu, Suihua

Author_Institution

RAWCom Lab., Colorado State Univ., Fort Collins, CO, USA

Volume

1

fYear

2001

fDate

2001

Firstpage

136

Abstract

Tapped delay line RAKE receivers are commonly used to achieve path diversity gain in DS-CDMA systems. Maximum ratio combining is typically considered the optimal combining scheme when fading parameters can be perfectly tracked. Lee and Milstein (see IEEE Transactions on Communications vol.47, no.12, p.1897-1904, 1999) noted that MRC is not optimal because different diversity branches have different MAI power. However, Lee and Milstein´s combining scheme used inaccurate estimations of the MAI power. In this paper, the optimal combining scheme for DS-CDMA RAKE receivers based on the maximum likelihood criteria is derived. Simulation over Rayleigh frequency selective fading channels indicates the benefits over other combining schemes

Keywords

Rayleigh channels; code division multiple access; diversity reception; multiuser channels; radio receivers; radiofrequency interference; spread spectrum communication; DS-CDMA systems; MAI power; ML combining RAKE receiver; MRC; Rayleigh frequency selective fading channels; direct-sequence spread spectrum; diversity branches; fading parameters; maximum likelihood criteria; maximum ratio combining; multiple access interference; optimal combining; path diversity gain; simulation; Delay effects; Delay lines; Diversity methods; Diversity reception; Fading; Frequency; Mathematics; Maximum likelihood estimation; Multiaccess communication; Multipath channels;

fLanguage

English

Publisher

ieee

Conference_Titel

Communications, Computers and signal Processing, 2001. PACRIM. 2001 IEEE Pacific Rim Conference on

Conference_Location

Victoria, BC

Print_ISBN

0-7803-7080-5

Type

conf

DOI

10.1109/PACRIM.2001.953541

Filename

953541