The CFIP Lumina Series Full Outdoor Unit Technical Description and Configuration Guide
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Rev. 1.3
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© SAF Tehnika JSC 2010
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Examples of CFIP constellation diagrams under excellent conditions are shown below:
Figure 5.15.
Constellation diagram
– QPSK, 16APSK, 32APSK, 64QAM, 128QAM, 256QAM
5.2.5 Adaptive Equalizer
CFIP Lumina features adaptive equalizer, which is a filter that automatically adapts to
time-varying properties of a communication channel with selective fading, having a target to
compensate the inequalities in frequency response, mitigating the effects of multipath
propagation. In wireless telecommunications, using QAM modulation this filter equalizes not
only a separate quadrature channel, but provides a cancellation of cross-interference
between them.
In current CFIP device an adaptive equalizer is realized as complex-arithmetic 24-taps
digital FIR (Finite Impulse Response) filter. In other words, equalizer is a selective frequency
amplifier and attenuator, a device, which application to IF (Intermediate Frequency) band-
limited signal is schematically shown in the picture below:
Equalizer graph
Equalizer graph window shows adaptive equalizer taps‟ coefficients, which at a set time
moment minimize multipath fading effect in channel.
Example of equalizer taps‟ coefficients and its frequency response in case of a normal
operation is shown below: