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RF65
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Note that the noise floor of the receiver at the demodulator input depends on:
The noise figure of the receiver.
The gain of the receive chain from antenna to base band.
The matching - including SAW filter if any.
The bandwidth of the channel filters.
It is therefore important to note that the setting of
OokFixedThresh
will be application dependant. The following procedure
is recommended to optimize
OokFixedThresh
.
Set RF65 in OOK Rx mode Adjust
Bit Rate, Channel filter BW Default
OokFixedThresh
setting
No input signal
Continuous Mode
Monitor DIO2/DATA pin
Increment
OokFixedThresh
Glitch activity
on DATA ?
Optimization complete
Figure 9. Floor Threshold Optimization
The new floor threshold value found during this test should be used for OOK reception with those receiver settings.
3.4.13.2. Optimizing OOK Demodulator for Fast Fading Signals
A sudden drop in signal strength can cause the bit error rate to increase. For applications where the expected signal drop
can be estimated, the following OOK demodulator parameters
OokPeakThreshStep
and
OokPeakThreshDec
can be
optimized as described below for a given number of threshold decrements per bit. Refer to
RegOokPeak
to access those
settings.
3.4.13.3. Alternative OOK Demodulator Threshold Modes
In addition to the Peak OOK threshold mode, the user can alternatively select two other types of threshold detectors:
Fixed Threshold: The value is selected through
OokFixedThresh
Average Threshold: Data supplied by the RSSI block is averaged, and this operation mode should only be used with
DC-free encoded data.