Title :
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
fDate :
5/1/2001 12:00:00 AM
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;
Journal_Title :
Microwave Theory and Techniques, IEEE Transactions on
