CC2642R: RSSI value in case of using Coded PHY

Nona

Part Number: CC2642R

Team,
My customer who employs the CC2642 for the monitoring system is facing a strange behavior of the RSSI reading (using SmartRF Studio). This system uses the CC2642s in very close proximity.

PHY	RSSI[dBm]	PER[%]
1M PHY(basic rate)	-26.0	0.0
Coded PHY with S=2	-10.1	0.0
Coded PHY with S=8	-10.1	0.0

From my experience, the RSSI has about 70dB range from -27dBm to -97dBm normally. The result of the Basic rate (1M PHY) is reasonable, I believe. However, the result above displays -10.1 dBm when the Coded PHY is used.

Is it the expected result?
Could I have your comment?

Regards,
Nonaka

over 5 years ago

0 Vetle S over 5 years ago

TI__Intellectual 1670 points

Hi Nonaka,

I am assigning an expert to verify with a test setup.

Best regards,

Vetle

0 Elin W over 5 years ago

TI__Genius 14845 points

Hi Nonaka,

I will test this early next week to see if I can reproduce your measurements, I'll let you know as soon as I have an update.

Thanks,
Elin

0 Elin W over 5 years ago

TI__Genius 14845 points

Hi Nonaka,

Apologies for the delay, I haven't been able to perform the test yet. I will give an update as soon as I can.

Thanks,
Elin

0 Elin W over 5 years ago

TI__Genius 14845 points

Hi Nonaka,

I discussed your questions with the R&D team and they assured me that this is expected behavior. When the devices are in close proximity, the receiver will be saturated due to the energy level of the signals on the antenna. The RSSI value of saturation is dependant on PHY, therefore there is a difference between coded and 1M.

To avoid this behavior, I would recommend you to either lower Tx power or place the devices further apart.

Thanks,
Elin

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CC2642R: RSSI value in case of using Coded PHY