Clarification on SNR Units in nrf_modem_dect_phy_rx_pcc_status

[Isitha]

I’m using the DECT Shell perf command to evaluate DECT NR+ performance.

Could you please clarify the units and scaling of the snr field in nrf_modem_dect_phy_rx_pcc_status?

In my measurements, I observe SNR values exceeding 100 at close range and negative SNR values at longer distances.

Ex-

PCC RX: RSSI: min: -55, max: -41dBm
PCC RX: SNR: min: 26, max: 104

PCC RX: RSSI: min: -105, max: -88dBm
PCC RX: SNR: min: -14, max: 76

Is this SNR value reported in dB, a fixed-point format, or an internal modem defined scale?

Thank you for your assistance!

[Øyvind]

Hello, 

I have forwarded this internally to get more information on this topic. I hope to have an answer by end of tomorrow or Friday. 

Kind regards,
Øyvind

[Øyvind]

Hello,

From nrf_modem_dect_phy.h we find nrf_modem_dect_phy_rx_pcc_status and its SNR value defined with:

	/**
	 * @brief Received signal to noise indicator (SNR).
	 *
	 * Values are dB values with 0.25 dB resolution (Q13.2).
	 *
	 * See 8.4 in @ref DECT-SPEC "DECT-2020 NR Part 2".
	 */
	int16_t snr;

Kind regards,
Øyvind

[Isitha]

Thank you!

[Øyvind]

You're welcome!