|Paper title: RECONFIGURABLE COMPLEX DIGITAL DELTA-SIGMA MODULATOR SYNTHESIS FOR DIGITAL WIRELESS TRANSMITTERS
Author(s): CREPIN NSIALA NZÉZA, ANDRÉAS KAISER, ANDREIA CATHELIN,
Digital generation of radio-frequency signals is a key concept of software defined radio.
One of the main difficulties for multi-standard transmitter design based on Delta-Sigma
(ΔΣ) modulators is to respect the different specifications in terms of out-of-band
spurious emission. Focusing on the TX path of a UMTS/DCS1800 mobile phone, we
propose hereinafter an efficient method aiming at synthesizing a complex 5th-order ΔΣ
modulator which respects the targeted standards spurious specifications. The use of a
complex noise transfer function allows a better optimization of noise shaping. In
addition, this approach eases the reconfiguration of the modulator, and, it is a powerful
tool for all order (real and complex) ΔΣ modulators synthesis, as it will be illustrated.
Keywords: Delta-Sigma modulator, Software defined radio.Year: 2009 | Tome: 54 | Issue: 4 | Pp.: 385-394
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