Title :
A QAM modulator for WCDMA base station
Author :
Vankka, Jouko ; Sumanen, Lauri ; Halonen, Kari
Author_Institution :
Electron. Circuit Design Lab., Helsinki Univ. of Technol., Espoo, Finland
Abstract :
A QAM modulator has been developed and implemented with programmable logic devices (PLDs). D/A converters were implemented in 0.5 μm CMOS technology. A conventional QAM modulator needs four multipliers, two adders and sine/cosine ROMs. The designed CORDIC based QAM modulator has about same logic complexity as two multipliers and an adder with the same word sizes. The QAM modulator accepts 12 b in-phase and quadrature data streams, interpolates them by 16 and upconverts the baseband signal to a selected center frequency. The QAM modulator is designed to fulfil the spectrum and error vector magnitude (EVM) specifications of the wideband code division multiple access (WCDMA) system
Keywords :
CMOS digital integrated circuits; application specific integrated circuits; code division multiple access; digital arithmetic; digital-analogue conversion; mobile radio; modulators; programmable logic devices; quadrature amplitude modulation; signal processing; 0.5 micron; CMOS technology; CORDIC based modulator; D/A converters; DAC; PLDs; QAM modulator; WCDMA base station; baseband signal upconversion; error vector magnitude specifications; interpolation; programmable logic devices; wideband CDMA system; wideband code division multiple access; Base stations; CMOS logic circuits; CMOS technology; Logic design; Logic devices; Modulation coding; Multiaccess communication; Programmable logic devices; Quadrature amplitude modulation; Read only memory;
Conference_Titel :
ASIC/SOC Conference, 2000. Proceedings. 13th Annual IEEE International
Conference_Location :
Arlington, VA
Print_ISBN :
0-7803-6598-4
DOI :
10.1109/ASIC.2000.880677
