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LAUNCHXL-CC1310: Measure/Calculate Eb/No or C/N

Tom Karlsson
Prodigy 150 points
Part Number: LAUNCHXL-CC1310
Other Parts Discussed in Thread: CC1310

Hi

I want to measure and calculate the Eb/No (energy per bit / noise power spectral density) or possibly C/N (carrier to noise) with my CC1310. 

First of all, is it possible?

If so, how do I measure it? What kinds of signals do I have access to?

Please help me out, I am a bit confused.

Best regards.

  • 0
    TI__Guru**** 317180 points
    You can find some information on this in e2e.ti.com/.../1562985

    What is your main goal with the measurements?
  • 0 in reply to TER
    Prodigy 150 points
    Hi!

    The link you posted discuss internal receiver SNR.

    I want to measure Eb/No in the air. To get a hint if the position is a good spot to deploy my unit at.

    With the a measured Eb/No value, I can use existing an existing graph to calculate BER for the Eb/No value, for different modulations (CC1310 uses GFSK right?). I want to measure this with only CC1310, is that possible?

    Best regards
  • 0 in reply to Tom Karlsson
    TI__Guru**** 317180 points
    Eb/No is not possible to measure directly since all receivers will have a given Rx bandwidth. Hence you would need to calculate Eb/No from C/ N and for the later you would need to know the exact power level.

    For your use, you can try to look at the PER and RSSI in combination. A good location should have a better RSSI value (but a better RSSI value can also be due to noise etc)
  • 0 in reply to TER
    Prodigy 150 points

    Hi, thanks for the answer!

    This application will only be used for CC1310 and they all have the same Rx bandwidth, right?

    How do you suggest to do the C/N -> Eb/No calculation / conversion ? If possible, do you have any formal source for it (to use in a report)?
    I am asking since I have read about that conversion, but some engineers disagree about it, e.g. this article seems to be popular but have some criticism about as well: http://sss-mag.com/ebn0.html

    If i am not wrong, PER and BER is the same thing? To find a good indication of PER or BER values, to many packets/bits have to be sent to make it useful as a parameter for low energy deployment tool.


    Best regards,
    Tom Karlsson

  • 0 in reply to Tom Karlsson
    TI__Guru**** 317180 points
    The Rx bandwidth is programmable.

    The Eb/No article I found link to the link you refer to. I didn't read the details but for me it looks like it's highlighting a typical issue: The fundamental theoretical equations is not easy to use in the real world. That is why I recommended looking at PER/ RSSI since this is parameters directly from the RF chip and that shows directly if you have placed the unit a good place. If you go via a theoretical equation you risk that some real life parameters are not taken into account.

    You can calculate BER from PER (en.wikipedia.org/.../Bit_error_rate). How many packets depends a bit on resolution/ accuracy. If you want to measure PER < 1 % you need more than 100 packets as an example.