How to measure GPS antenna sensitivity?

[Yusuke]

I would like to compare GPS antenna sensitivity between DK board and a custom board. What AT command achieves it? Thanks.

[Heidi]

Hi!

I believe you can use %XRFTEST to read this information. Take a look and let me know if this is what you were looking for.

Best regards,

Heidi

[Yusuke]

Hi,

%XRFTEST=2,1,0,0

This command indicates <param0> is set to 0, which means gain is −105 dBm. Is this standard value? If not, what value should be standard?

[Heidi]

Hi, yes -105 dBm is the default gain. 

[Yusuke]

I'm trying to measure the GPS sensitivity, but not sure the value is correct

in at command datasheet, example snr value is positive

%XRFTEST=2,1,0,0
%XRFTEST: 514,-19968
OK

# %XRFTEST: <snr>,<antenna_power>

However, when I receive the data, the value is always negative, although A-GPS works properly. Do I miss any setting to get the GPS SNR?

<input at commands>

AT+CFUN=0
AT%XSYSTEMMODE=1,0,1,0
AT%XMAGPIO=1,0,0,1,1,1574,1577
AT%XCOEX0=1,1,1570,1580
AT+CFUN=31
AT%XRFTEST=2,1,0,0

<output>

%XRFTEST: -93,-22680

[Hakon]

I'm not sure why you're getting a high SNR value. It could be because of high noise levels, but I will ask about it internally to be sure.

[Yusuke]

Thank you!