Data Sheet

Page 38
RFM95/96/97/98(W)
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WIRELESS & SENSING PRELIMINARY DATASHEET
Channel Activity Detection
The use of a spread spectrum modulation technique presents challenges in determining whether the channel is already in
use by a signal that may be below the noise floor of the receiver. The use of the RSSI in this situation would clearly be
impracticable. To this end the channel activity detector is used to detect the presence of other LoRa
TM
signals. Figure 10
shows the channel activity detection (CAD) process:
Figure 10. LoRa
TM
CAD flow