nRF91 AT commands: %XRFTEST RX testing

CAUTION:

This command transmits power to the selected RF band and may violate the radio directives of the region or country. Make sure that the equipment is in an RF-shielded room or connected to an RF cable so that RF power will not leak.

The command parameter and its value are the following:

<test>: 1 – TX

TX ON

<operation>: 1 – ON

TX ON has the following parameters:

<param0>

3GPP band number.

<param1>

Frequency [100kHz].

Valid range 6000–22000 (corresponds to 600.0 MHz–2200.0 MHz).

<param2>

TX signal power at the System in Package (SiP) antenna port [dBm].

Valid range from +23 to −50.

<param3>

System mode.

Valid range 0–1. NB1 (0) or M1 (1).

Note: Some LTE bands may be supported in only one of the system modes. To ensure that the band can be used, set the correct mode with %XSYSTEMMODE.

<param4>

Modulation.

0 – QPSK

1 – 16QAM

2 – Reserved

3 – BPSK

4 – CW

M1: QPSK, 16QAM, and CW

NB1: QPSK, BPSK, and CW

Note:

If <param4> = CW, in system modes NB1 and M1 the CW tone is offset by 255 kHz from the frequency given in <param1>.v1.0.xv1.1.xv1.2.x
If <param4> = CW, the CW tone is offset from the frequency given in <param1> by 48.75 kHz in system mode NB1 and by 401.25 kHz in system mode M1.v1.2.x≥1pti_v1.1.x≥1

<param5>, <param6>, <param7>

<param5> Resource Block (RB)/Tone count

<param6> RB/Tone start position

<param7> Subcarrier spacing 0 – 15 k, 1 – 3.75 k.

If <param4> = CW, then <param5>, <param6>, and <param7> = 0 (do not care)

<param8>v1.2.x: System bandwidth.; 0 – NB1; 1 – 1.4 M; 2 – reserved; 3 – 5 MHz; 4 to 6 – reserved
<param9>v1.2.x: Narrowband index.; 0 – 1.4 M; 0 to 3 – 5 M; Defined in 3GPP TS 36.211 Ch. 6.2.7.
Note: <param9> has effect only when <param8> is 3 (5 MHz).
<param10>v1.2.x≥1pti_v1.1.x≥1: TX burst mode.; 0 – Disable TX burst mode; 1 – Enable TX burst mode; For more information, see TX burst mode.

The allowed combinations for <param5>, <param6>, and <param7> for both system mode (<param3>) values are listed in the following table:

Table 1. Allowed parameter combinations for <param5>, <param6>, and <param7> in system modes NB1 and M1
System mode <param3>	RB/Tone count <param5>	RB/Tone start position <param6>	Subcarrier spacing <param7>
NB1 (0)	1	0–11	0
	3	0, 3, 6, 9	0
	6	0, 6	0
	12	0	0
	1	0–47	1
M1 (1)	1	0–5	0
	2	0–4	0
	3	0–3	0
	4	0–2	0
	5	0–1	0
	6	0	0

Note: In system mode M1, subcarrier spacing 3.75 kHz is not allowed.

Response syntax when <operation> is ON:

%XRFTEST: <antenna_power>

The response value is the following:

<antenna_power>: Internally measured TX power at the SiP antenna port in q4 dBm. q4 means that dividing the result by 2⁴ = 16 gives dBm.

The following command example enables the RF transmitter for Band 5, 830.0 MHz, +17 dBm, NB1, BPSK, 12 tones, tone start position 0, subcarrier spacing 15 kHz, system bandwidth NB1, NB index 0, TX burst mode disabled:

%XRFTEST=1,1,5,8300,17,0,3,12,0,0,0,0,0
%XRFTEST: 271 OK

Note: 271/16 = 16.9 dBm

The following command example enables the RF transmitter for Band 5, 830 MHz, +17 dBm, M1, 16-QAM, 6 RB, RB start position 0, subcarrier spacing 15 kHz, system bandwidth 5 MHz, NB index 3, TX burst mode disabled::

%XRFTEST=1,1,5,8300,17,1,1,6,0,0,3,3,0
%XRFTEST: 271 
OK

TX burst mode

TX burst mode is enabled when <param10> is set to 1. The mode allows non-continuous TX transmission. The ON and OFF periods are based on the reference measurement channel uplink subframe scheduling that is defined for M1 in 3GPP TS 36.521 Annex A, Section A.2.2 and for NB1 in 3GPP TS 36.521 Annex A, Section A.2.4. The burst signal is transmitted until the TX OFF command is given.v1.2.1pti_v1.1.x≥1

The following table describes the different waveforms supported by <param3>, <param4>, <param5>, and <param7>:

Table 2. Allowed parameter combinations for <param3>, <param4>, <param5>, and <param7> in system modes NB1 and M1 when using TX burst mode
System mode <param3>	Modulation <param4>	RB/Tone count <param5>	Subcarrier spacing <param7>
NB1 (0)	0	1	1
	0	1	0
	0	3	0
	0	6	0
	0	12	0
	3	1	0
	3	1	1
M1 (1)	0, 1	1–6	0

Response syntax when <operation> is ON and TX burst mode is enabled:

%XRFTEST: OK

The following command example enables the RF transmitter for Band 5, 830 MHz, +17 dBm, M1, 16-QAM, 6 RB, RB start position 0, subcarrier spacing 15 kHz, system bandwidth 5 MHz, NB index 3, TX burst mode enabled:

%XRFTEST=1,1,5,8300,17,1,1,6,0,0,3,3,1
OK

TX OFF

<operation>: 0 – OFF

The following command example disables the RF transmitter:

%XRFTEST=1,0
OK

Note: Always send the OFF command before sending another ON command.

TX testing

TX ON

TX burst mode

TX OFF