To measure Signal-to-Noise Ratio (SNR) correctly, the Carrier Wave (CW) offset must be +330 kHz for the M1 mode and +45 kHz for NB1.
The parameters and their values are the following:
- <test>
- 3 – RX SNR
- <operation>
- 1 – ON
Note: "OFF" is not needed due to automatic stop.
- <param0>
- 3GPP band number. Use 24 for Global Positioning System (GPS) reception.
- <param1>
- Frequency 100 kHz (,i.e. 2140 MHz is expressed as 21400).
- <param2>
- RX signal power at the System in Package (SiP) antenna port in dBm.
Valid
range from −127 to −25.
- <param3>
- System mode.
Valid range 0–1. NB1 (0) or M1 (1).
- <param4>v1.2.xpti_v1.1.x≥1
- Enabling AFC correction during SNR test.
1 –
Enable
0 – Disable
If <param4> is not given, AFC
correction is disabled.
Response syntax when <operation> is ON:
%XRFTEST: <snr>,<antenna_power>
The response parameters and their values are the following:
- <snr>
- Result of the Serial Number (SNR) measurement in q4 dB. q4 means that
dividing the result by 24 = 16 dB.
- <antenna_power>
- Measured signal power at the SiP antenna port in q8 dBm.
q8 means divided dividing the result by 28 = 256 gives dBm.
The following command example enables the RX SNR measurement and RF receiver for Band 1,
2140.0 MHz, −65 dBm, M1 mode, AFC correction enabled:
%XRFTEST=3,1,1,21400,-65,1,1
%XRFTEST: 496,-17002
OK
Note: 496/16 = 31 dB and −17002/256 = −66.4 dBm.