[MKW41Z] CCA on GENFSK

cancel
Showing results for 
Show  only  | Search instead for 
Did you mean: 

[MKW41Z] CCA on GENFSK

1,071 Views
domenico_virgil
Contributor II

Hi,

we need to perform a CCA using GENFSK.

From the datasheet we saw that the CCA treshold is supported only in the ZLL, but we want to put a treshold in software to compare with ED value.

In the documentation of the Receiver Digital Module in MKW41Z Reference Manual (page 1673), is reported that the Digital Module can return the ED value from the rx_cca_ed_lqi which, in turn, uses the w/rssi signal from rx_agc Module.

So we supposed, following the manual, that we can use XcvrFskGetInstantRssi test function provided in MCUXPRESSO_SDK v 2.2.0 to perform an RX WarmUp, read the XCVR CCA_ED_LQI_STAT_0 register and get the ED value, but this approach doesn't work.

The table 45-20 (page 1686 - Reference Manual) shows the two signals which needs to be configured to raise CCA1/ED
meas. state (wideband mode). The signal cca1_ed_trig should be triggered on RX WarmUp, the second one, sfd_aa_match, has no references in the Reference Manual.

So the questions are:

1) It's possible to use RSSI/CCA1/LQI module in direct manner using the Receiver Digital Module and it's registers, without using the ZLL Module registers?

2) If not, is there a way to software compute the ED, starting from the istant RSSI value?

We think that once computed the ED, we can address in our firmware a CCA threshold value and design a CA strategy to avoid collisions.

Have you any hint which can put us on the right path?

Best Regards,

Domenico Virgilio

Labels (1)
Tags (3)
4 Replies

871 Views
estephania_mart
NXP TechSupport
NXP TechSupport

Hello, 

I will need to investigate in further detail if this it's possible in the way you want to, as I'm not sure how it can be implemented when using the GFSK. 

I'll need some time to check this out. 

Sorry for the inconveniences this might cause you. 

Regards, 
Estephania 

0 Kudos

871 Views
domenico_virgil
Contributor II

Hi Estephania,

thank you for the answer.

I hope that what I want to do is possible.

Just a question: since the RSSI / CCA1 / LQI module is located in the RX Digital, it would be possible to use it bypassing the various Link Layers and directly using the RX Digital module, without going through the GENFSK, if the GENFSK does not support this functionality?

Best regards,

Domenico Virgilio

0 Kudos

870 Views
estephania_mart
NXP TechSupport
NXP TechSupport

Hello, 

Unfortunately, I was not able to locate any further information regarding the topic, but I do not believe it is possible to bypass the different link layers as it would appear that when setting the GFSK you can't use it due to the radio settings, nonetheless, you can try it. 


Sorry for the inconveniences this might cause you, but all the information that you have it's the one available. 


Regards, 
Estephania 

0 Kudos

870 Views
domenico_virgil
Contributor II

Please, any news about this? It's a very urgent task for us.

0 Kudos