A nonzero intermediate frequency likelihood acquisition scheme for CDMA system

Author

Yuchu, Ma ; Xuemai, Gu ; Naitong, Zhang

Author_Institution

Commun. Res. Center, Harbin Inst. of Technol., China

fYear

2000

fDate

2000

Firstpage

479

Lastpage

483

Abstract

A nonzero intermediate frequency (IF) likelihood acquisition scheme for PN codes is introduced in this paper. The received signal is first downconverted to IF, and then direct sampled in IF using a 1-bit A/D converter. After the digitalization, the sampled data is detected using a hybrid likelihood acquisition scheme. Using this structure, problems, due to large noise figure of the analog mixer or active filters or due to amplitude and phase imbalance between low-frequency in-phase and quadrature-phase channels, can be avoided. An algorithm which allows easy implementation of the acquisition scheme is also derived. The performance and algorithm are verified by computer simulation

Keywords

analogue-digital conversion; code division multiple access; pseudonoise codes; signal detection; signal sampling; spread spectrum communication; A/D converter; CDMA system; PN codes; hybrid likelihood acquisition scheme; nonzero intermediate frequency likelihood acquisition scheme; nonzero-IF likelihood acquisition scheme; received signal downconversion; Active filters; Algorithm design and analysis; Computer simulation; Frequency synchronization; Multiaccess communication; Noise figure; RF signals; Receivers; Spread spectrum communication; Voltage-controlled oscillators;

fLanguage

English

Publisher

ieee

Conference_Titel

Personal Wireless Communications, 2000 IEEE International Conference on

Conference_Location

Hyderabad

Print_ISBN

0-7803-5893-7

Type

conf

DOI

10.1109/ICPWC.2000.905904

Filename

905904