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IWRL6432: Range resolution calculation in motion and presence detection

Daniel

Prodigy 205 points

Part Number: IWRL6432

Hi TI experts,

In the 'motion and presence detection' of SDK 5.4.0.1, in dpc.c, line 1649 calculates params->rangeStep as follows:
params->rangeStep = (MMWDEMO_RFPARSER_SPEED_OF_LIGHT_IN_METERS_PER_SEC * (gMmwMssMCB.adcSamplingRate * 1.e6)) / (2.f * slope * (2*params->numRangeBins));

If I change the calculation to:
params->rangeStep = (MMWDEMO_RFPARSER_SPEED_OF_LIGHT_IN_METERS_PER_SEC * gMmwMssMCB.adcSamplingRate * 1e6) / (2.f * slope * gMmwMssMCB.profileComCfg.h_NumOfAdcSamples);

Would there be any issues?

8 months ago

0 Abhishek Karkisaval 8 months ago

TI__Genius 9010 points

Hi,

Thank you for your query. Please allow us a couple of days to respoond

Regards

0 Josh Dye 8 months ago

TI__Genius 16641 points

Hello,

There would be issues with this code if numAdcSamples is configured to be something other than a power of 2. When numAdcSamples is a power of 2 then numRangeBins = numAdcSamples/2 however if numAdcSamples is not a power of 2, then numRangeBins = (next power of 2 of numAdcSamples)/2.

Best Regards,

Josh

0 Daniel 8 months ago in reply to Josh Dye

Prodigy 205 points

Hi Josh,

So in dpc.c, params->rangeStep refers to the range inter-bin resolution rather than the range resolution in the mmWave Sensing Estimator 2.4.0, correct?

Best regards,

Daniel

+1 Josh Dye 8 months ago in reply to Daniel

TI__Genius 16641 points

Hi Daniel,

Yes, that is correct.

Best Regards,

Josh