IIIE   20352
INSTITUTO DE INVESTIGACIONES EN INGENIERIA ELECTRICA "ALFREDO DESAGES"
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Spectral characteristics of a piecewise linear function in modeling power amplifier type nonlinearities
Autor/es:
M.Y. CHEONG; S. WERNER; J. E. COUSSEAU; R.WICHMAN
Lugar:
Estambul
Reunión:
Simposio; 2010 IEEE 21st International Symposium on Personal Indoor and Mobile Radio Communications (PIMRC); 2010
Institución organizadora:
IEEE
Resumen:
Nonlinear effects of a power amplifier (PA) in communications systems
include spectral spreading, which causes adjacent channel interference.
For predistorter design, it is crucial to employ a model that can
sufficiently model the intermodulation distortion (IMD) caused by the
PA. The order of IMD generated by a polynomial is determined by its
highest order basis. For a piecewise linear function, the order of
nonlinearity cannot be directly deduced from its basis function. This
paper investigates how IMD is introduced by the simplicial canonical
piecewise linear (SCPWL) function. We examine the operation imposed by
the SCPWL basis function on sinusoid and multi-tone signal in the time
domain and frequency domain. Our analysis results in expressions that
can be used to predict the output spectrum of the SCPWL basis. The SCPWL
basis operation involves spreading of the input signal spectrum. The
output spectrum of each SCPWL basis includes infinite IMD components.
The IMD order of the SCPWL model is not determined by the highest order
basis. Instead, the number of SCPWL parameters, i.e., the number of
linear affine segments that defines the function, determines how
accurately it can model the IMD components.