Prediction of a CDMA output spectrum based on intermodulation products of two-tone test

Author

Yi, Seung-June ; Nam, Sangwook ; Oh, Sung-Hoon ; Han, Jae-Hee

Volume

49

Issue

5

fYear

2001

fDate

5/1/2001 12:00:00 AM

Firstpage

938

Lastpage

946

Abstract

A prediction method of a code-division multiple-access (CDMA) output spectrum based on intermodulation (IM) products of a two-tone test is proposed in this paper. An RF power amplifier is mathematically modeled by a complex envelope transfer function and, using this model, analytical expressions of IM products and a CDMA output spectrum are derived, respectively. By combining these two expressions, we finally derive an analytical expression that relates IM products to a CDMA output spectrum. It is shown in this expression that not only AM-AM, but also AM-PM distortion affects the CDMA output spectrum. Comparison between the measured and predicted results shows that the output spectrum predicted by this method agrees well with the measured spectrum

Keywords

code division multiple access; digital radio; intermodulation distortion; mobile radio; power amplifiers; radio transmitters; radiofrequency amplifiers; transfer functions; AM-AM distortion affects; AM-PM distortion affects; CDMA output spectrum; IM products; RF power amplifier modelling; code-division multiple-access; complex envelope transfer function; intermodulation products; mathematical model; prediction method; two-tone test; Analytical models; Distortion measurement; Mathematical model; Multiaccess communication; Power amplifiers; Prediction methods; Radio frequency; Radiofrequency amplifiers; Testing; Transfer functions;

fLanguage

English

Journal_Title

Microwave Theory and Techniques, IEEE Transactions on

Publisher

ieee

ISSN

0018-9480

Type

jour

DOI

10.1109/22.920152

Filename

920152