Procedure and commands for determining TX power ceilings

This section describes the procedure and the commands for determining the maximum TX power at which the Spectral Emission Mask (SEM) and Error Vector Magnitude (EVM) requirements are met for a particular modulation and frequency band using the radio test software and the corresponding sample. The values are then used to derive TX power ceilings.

The following flow chart gives an overview of the procedure, which is repeated for multiple modulations and frequency bands.

Figure 1. Procedure for determining the maximum TX power

The procedure is performed at nominal voltage and room temperature.

The following table presents the commands for determining the maximum TX power.

wifi_radio_test init <channel_num>

wifi_radio_test tx_pkt_tput_mode <frame_format>

wifi_radio_test tx_pkt_rate <data_rate>

wifi_radio_test tx_pkt_mcs <mcs>

wifi_radio_test tx_power <tx_power>

wifi_radio_test tx 1

wifi_radio_test tx 0

Wi-Fi® Radio test sample in the nRF Connect SDK is used for this procedure. For more information and subcommand details, see Wi-Fi Radio test subcommands.

The nine devicetree parameters that constitute the board TX power ceilings are each determined performing the steps described in Procedure for determining the maximum TX power, with only the rate (modulation) and operating channel varying. It is recommended that a minimum of three boards are measured and the lowest maximum transmit power is used as the devicetree parameter.

The following table describes the modulation and channel to be used for measuring each devicetree parameter.