Channel Sounding - Event, Subevent, Procedure count, other parameters

[parvez]

I have few doubts in the follwoing imoplementation:
For the provided set of parameters, when procedure count is 0, the estimated distance is printed for 6/7/8 sets of 72 channels IQ data in each iteration whereas If I make procedure count =1, The distabce is displayed after one set of 72 channels IQ dataset. For the same set of parameters timings,

1. I am unable to understand how does only one set of 72 channels is displayed when procedure count =1.  Can anyone explain with timings howmany sets of  72 channels data is displayed/ taekn into consideration prior giving thge estiimated distance. 
2. Can we able to change the FFT size, Can any one guide me how to cghnage these parameters./
3. Can anyone present the better clarity on the event/subevents/steps as per the procedure couint takes place with timings so that anyone can esaily calcute it exactly.
4. Can we chaneg teh numbers channels ussed per saye from  72 to only 36 cjhannels. can anyone guide me how to perform it.
Can anyone explain the channel map repition = 3, and channel jhump  in this context.

6. What is the maximum power which is used defaultly - 0x80. What is teh amximum distanbce, I can measure with the current default power settings. Is there any AGC to adjust the power wrt to distance.

7. Can we perform  2x2 antenna configuration in channel sounding. Can you please suggest the parameters to be set accordingly.

Thank you 

[Amanda Hsieh]

Hi, 

1. I am unable to understand how does only one set of 72 channels is displayed when procedure count =1.  Can anyone explain with timings howmany sets of  72 channels data is displayed/ taekn into consideration prior giving thge estiimated distance. 

 max_procedure_count = 1 means there is only one procedure. See this post and these lines. 

2. Can we able to change the FFT size, Can any one guide me how to cghnage these parameters./

Do you mean CONFIG_BT_CS_DE_NFFT_SIZE? If so, it's an internal config, so it cannot be modified by the user. 

3. Can anyone present the better clarity on the event/subevents/steps as per the procedure couint takes place with timings so that anyone can esaily calcute it exactly.

Check out this post. 

4. Can we chaneg teh numbers channels ussed per saye from  72 to only 36 cjhannels. can anyone guide me how to perform it.

It’s possible to set the channel map used during the CS procedure to enable only 36 channels when creating the CS configuration (see bt_le_cs_create_config() API). Another way to do this is using Set CS Channel Classification command (see bt_le_cs_set_channel_classification()). 

Please be aware that this may negatively impact the algorithm. The IFFT is not too happy with missing channels. Other algorithms may not suffer that much so as always, it depends.

Can anyone explain the channel map repition = 3, and channel jhump  in this context.

Check out bt_conn_le_cs_config.

6. What is the maximum power which is used defaultly - 0x80. What is teh amximum distanbce, I can measure with the current default power settings. Is there any AGC to adjust the power wrt to distance.

The range is limited by the regular BLE connection range. I can’t provide exact values, though.

Check out this post on how to adjust the tx power. 

7. Can we perform  2x2 antenna configuration in channel sounding. Can you please suggest the parameters to be set accordingly.

Check out this post. 

Regards,
Amanda H.

[parvez]

Thank you amanda for your help.