SWRA682 December   2020 CC1310 , CC1312PSIP , CC1312R , CC1314R10 , CC1350 , CC1352P , CC1352P7 , CC1352R , CC1354P10 , CC1354R10

 

  1.   Trademarks
  2. 1 Introduction
  3. 2 Recommended Test Setup
  4. 3 Overrides
  5. 4 Find the Needed RX BW
  6. 5 How to Set the Deviation
  7. 6 Theoretical Sensitivity
  8. 7 Determine AGC_REF Level
  9. 8 Determine Anti-Aliasing BW
  10. 9 Determine PA Ramp Settings
  11. 10Intermediate Frequency (IF)
  12. 11LNA Ib Offset
  13. 12Sensitivity and Selection of Sync Word
  14. 13Narrowband
    1. 13.1 Frequency Offset Tolerance
    2. 13.2 Low Datarate
    3. 13.3 Phase Noise
  15. 14RSSI Offset

5 How to Set the Deviation

Theoretically, there is an optimum separation/symbol rate setting if you simultaneously minimize the receiver filter bandwidth. Every halving of receiver filter bandwidth improves sensitivity by 3 dB whereas sensitivity vs separation/datarate decreases with about 1.5-2.5 dB per halving down to a certain limit where the loss increases very fast. In our experience a modulation index (h =2 x deviation/symbol rate = separation/symbol rate ) = 0.5 - 1 is a good design compromise.

For 4-GFSK the modulation index for inner symbols should be >= 1/3. Lower modulation index will degrade sensitivity significantly.