• Resolved

CC1101 Sensitivity Testing in MSK Mode

From looking at datasheet it appears I cannot duplicate the CC1101 MSK modulation exactly using a signal generator.  Is that opinion correct?

How does TI suggest checking the sensitivity in MSK mode using a signal generator? By sending raw data not packets?



  • Your opinion is correct..

    When MSK modulation is enabled, the DEVIATION_M field sets the fraction of symbol period used for phase change.

    DEVIATION_M = 0 means that the phase is changed within 1/8 of a symbol.

    DEVIATION_M = 7 means that the the whole symbol period is used to change phase.

    Higher data rates need faster phase changes.

    CC1101 configured for MSK modulation will not receive a 2-FSK modulated signal from an arbitrary transmitter (incl CC1101). Reason being that the CC1101 MSK is inverted.

    • TX(2-FSK) -> CC1101(MSK) does not work
    • TX(2-FSK, invertert) -> CC1101(MSK) works

    You should consider using 2-GFSK with a modulation index = 0.5 instead of the CC1101 MSK option.


  • In reply to Sverre:

    Thank you for the information.