ZA,ADC Design Considerations foranUMTS Receiver
Stijn Reekmans, Pieter Rombouts · 2006
Thispapergives aninsight onhowtoderive the minimumrequired specifications bothfortheanti-aliasing filter (AAF)andtheanalog-to-digital converter (ADC)inthecaseof anUMTS receiver. Basedonthereceiver specifications, wecome upwithadesign planforbothdiscrete timeZA ADC aswell asforacontinuous timeZiAADC. I.INTRODUCTION Theability toprocess higher userbitrates isthemajor ob- jective oftoday's wireless systems. Tofulfill this demand, third generation (3G)wireless systems areintroduced. Forthese systems, wideband code-division multiple access (WCDMA) technology seemstobethewidely adopted airinterface. Rather thanbeing separated infrequency andtime, users are nowseparated byorthogonal codes. Here, wewill focus onthe FDD (Frequency Division Duplex) modeofUMTS (universal mobile telecommunication system), thestandard mostrelevant inEurope. Thepaperstarts bysummarizing theminimumreceiver specifications astheyarespecified inthestandardization documents. Next,a commonly usedreceiver topology, the low-IF receiver isdiscussed together withsomearchitectural issues. Finally, adesign planisgiven foradiscrete timeZA ADC aswellasforacontinuous timeZA ADC.