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Summary: SYNERGISTIC DESIGN OF DSP AND POWER AMPLIFIERS
FOR WIRELESS COMMUNICATIONS
P.M.ASBECK AND L.E.LARSON
Electrical and Computer Engineering Department
University of California, San Diego
La Jolla, CA, USA 92093-0407
E-mail: asbeck@ece.ucsd.edu
Co-design of DSP algorithms and power amplifier characteristics can lead to improved
efficiency and linearity through a variety of strategies, including: a) DSP control over bias
conditions, particularly the power supply voltage; b) predistortion; and c) DSP generation of
digital input signals for switching amplifiers. We envision for the future a generation of
"smart power amplifiers" in which DSP optimisation of amplifier parameters is carried out
for changing environments.
1 Introduction
One of the most important challenges for component design posed by mobile communication
systems is to maximise the power efficiency of the handset power amplifier, which is a main
determinant of battery talk-time. At the same time, with spectrally-efficient modulation formats
such as QPSK, the amplifier linearity must be sufficiently high that adjacent channel power
generation is kept within strict bounds. Compounding these problems is the fact that the output
power of a handset typically varies over many orders of magnitude as a result of changing
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