TY - GEN
T1 - Architecture and algorithms for generating general-purpose modulation signals
AU - Wang, Hua
AU - Kuang, Jingming
AU - Chen, Yan
AU - Xie, Yanan
AU - Xie, Xiang
PY - 2006
Y1 - 2006
N2 - In this paper, we introduce the architecture for implementing a wideband general purpose digital modulator which can generate commonly-used modulation format signals. The symbol rate of modulation signals can be from 500kS/s up to 45MS/S. In order to use the same analog low-pass filters (LPF) to cancel all image signals from D/A converter (DAC) under different output signal bandwidth, we employ Cascaded Integrator Comb (CIC) filter to interpolate so as for DAC to work within a specific range. In the meantime, we propose an algorithm to counteract the passband droop of CIC filter. Considering about the effect of sinc(x) by DAC on wideband signals, a similar algorithm is presented. For reducing the implementation complexity, all integrated adverse effects were compensated for by modifying the coefficients of Pulse Shaping Filter (PSF). The algorithm is verified by experiments and the modulator can produce digital modulation signals with good Error Vector Magnitude (EVM) and adjacent channel leakage power ratio (ACLR).
AB - In this paper, we introduce the architecture for implementing a wideband general purpose digital modulator which can generate commonly-used modulation format signals. The symbol rate of modulation signals can be from 500kS/s up to 45MS/S. In order to use the same analog low-pass filters (LPF) to cancel all image signals from D/A converter (DAC) under different output signal bandwidth, we employ Cascaded Integrator Comb (CIC) filter to interpolate so as for DAC to work within a specific range. In the meantime, we propose an algorithm to counteract the passband droop of CIC filter. Considering about the effect of sinc(x) by DAC on wideband signals, a similar algorithm is presented. For reducing the implementation complexity, all integrated adverse effects were compensated for by modifying the coefficients of Pulse Shaping Filter (PSF). The algorithm is verified by experiments and the modulator can produce digital modulation signals with good Error Vector Magnitude (EVM) and adjacent channel leakage power ratio (ACLR).
KW - CIC filter
KW - Modulation
KW - Pulse shaping filter
KW - Software defined radio
UR - http://www.scopus.com/inward/record.url?scp=36048993092&partnerID=8YFLogxK
U2 - 10.1109/IMTC.2006.236252
DO - 10.1109/IMTC.2006.236252
M3 - Conference contribution
AN - SCOPUS:36048993092
SN - 0780393600
SN - 9780780393608
T3 - Conference Record - IEEE Instrumentation and Measurement Technology Conference
SP - 1401
EP - 1404
BT - IMTC'06 - Proceedings of the IEEE Instrumentation and Measurement Technology Conference
T2 - IMTC'06 - IEEE Instrumentation and Measurement Technology Conference
Y2 - 24 April 2006 through 27 April 2006
ER -