nRF9160 - Details on Carrier-to-Noise-Density Ratio (C/N0) in $GPGSV Logs

[hwpk]

Hello,

I am currently evaluating the nRF9160 GPS receiver's performance in comparison to other manufacturers' receivers. As part of this evaluation, I am using the C/N0 level provided in the $GPGSV log to assess the receiver's sensitivity performance in a controlled environment.

I came across information in this link (Field verification of GNSS on the nRF91 Series) stating that the C/N0 level is manufacturer-dependent. To accurately compare C/N0 levels across different receivers from various manufacturers, I am seeking details on how the nRF9160 calculates the C/N0 level. Is there a specific document where I can find this information?

I am particularly interested in understanding the method used to estimate the C/N0 level, considering the various options I found in my research. Additionally, I would like to know how the receiver obtains values for received carrier power or noise density, both of which are essential for estimating C/N0 levels.

Thank you.

[Charlie]

Hi Hwansu,

The details of C/N0 estimation algorithm in MFW are not something we could share.

For your needs, generally speaking, the reported C/N0 level does not give a good indication of the sensitivity. If you want to compare the sensitivities of different receivers, you should find a way to attenuate the input signal level by adding attenuation to the antenna line or using a GNSS simulator. Then observe if receivers can still output a fix or not. Or observe the number of satellites in track, depending on what you are interested in.

Best regards,

Charlie