Title :
Test Signal Development and Analysis for OFDM Systems RF Front-End Parameter Extraction
Author :
Nassery, Afsaneh ; Erol, Osman Emir ; Ozev, Sule ; Verhelst, Marian
Author_Institution :
Dept. of Electr. Eng., Arizona State Univ., Tempe, AZ, USA
fDate :
6/1/2012 12:00:00 AM
Abstract :
Testing radio frequency (RF) transceivers requires the measurement of a diverse set of specifications, requiring multiple testing setups. This complicates load board design, debug, and diagnosis, as well as results in long testing time. In this paper, we present a single setup testing solution for orthogonal frequency-division multiplexing systems RF front-ends based on a loop-around scheme. With this technique, it is possible to determine gain and phase mismatch, inphase-quadrature time skew, and dc offset. Linear gain and IIP3 decouple the transmitter parameters from the receiver parameters. Although loop-around has been used in many forms, the basic challenge is to determine what input conditions will lead to accurate measurement and what form of modeling will yield this accuracy. To this end, we develop test signal design and multistep extraction techniques. Experimental results indicate that IIP3 can be extracted with 0.6 dB maximum error while phase mismatch and gain mismatch can be extracted with 0.3° and 0.6% maximum error. Our method is able to de-embed the characteristics of transmitter from those of receiver while it requires the analysis of only low-frequency digital baseband signals (I and Q branches) and eliminates the need for RF testers.
Keywords :
OFDM modulation; multiplexing; radio transceivers; IIP3 decouple; OFDM systems RF front-end parameter extraction; gain mismatch; inphase-quadrature time skew; linear gain; load board design; loop-around scheme; orthogonal frequency-division multiplexing systems RF front-ends; phase mismatch; radio frequency transceivers; receiver parameters; test signal analysis; test signal development; transmitter parameters; Accuracy; Parameter extraction; Radio frequency; Receivers; Testing; Transceivers; Transmitters; Orthogonal frequency-division multiplexing (OFDM); WiMax; power amplifiers; wireless local area network (WLAN);
Journal_Title :
Computer-Aided Design of Integrated Circuits and Systems, IEEE Transactions on
DOI :
10.1109/TCAD.2012.2183370