AWR2944EVM: Recover the maximum velocity in the Classical DDMA scheme

Hi Stan,

I am sorry for the delay, I had missed this thread.

brickporter said:

How can we recover the maximum velocity using hypothesis testing with zero padding or phase dithering?

We apply per chirp phase shifts to the TX antennae in such a manner that some region in the doppler space is left empty. We can later find this empty band to identify the rotation observed and hence disambiguate the max velocity:

Both of these figures have been taken from the doxygen docs of DPC DDMA. I would suggest going over the Doxygen documentation of the recently released SDK 4.2.0.3, as some improvements have been made.

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brickporter said:

For implementation, how does the cyclic memory shifting be applied to hypothesis test ?

The Doxygen documentation for the doppler DDMA DPU in the updated SDK 4.2.0.3 describes this, under the "DDMA Metric" heading.

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brickporter said:

why is the single target in the same range/Doppler bin assumed?

Hypothesis testing is done for each range bin and doppler sub-bin (i.e. the bins in a band in doppler space). The following calculation is used:

We have to assume that there is only one object in each of the six (or in general n) doppler bands for each doppler sub-bin for this calculation to produce intended results. If there are multiple objects at the same distance with velocities such that both objects fall in the same set of doppler bins (corresponding to S1-S6 in the formula above), the calculation above would fail, as finding the max of Z1..Z6 will not have the intended meaning.

Regards,

Aayush