CCS/AWR1843BOOST: Extending the unambiguous velocity measurement range using the function disambiguateVel

Rata Zhang

Part Number: AWR1843BOOST

Tool/software: Code Composer Studio

Hi，

In the MRRdemo,there is a function called disambiguateVel which extends the unambiguous velocity measurement range by 3x. There are two type chirps,fast chirp period is 65us, and slow chirp period is 78us.Why is disambiguation of up to 3x of the naive max-velocity obtained by the above configuration according to chinese remainder theorem?

Thanks,

Regards,

Rata

over 5 years ago

0 Raghunandan Kamath over 5 years ago

TI__Mastermind 22155 points

Rata,

Please see the below post for the answer:

https://e2e.ti.com/support/sensors/f/1023/t/684385

Thanks,

Raghu

0 Rata Zhang over 5 years ago in reply to Raghunandan Kamath

Expert 2840 points

Hi Raghu,

I have read the post and the document 'Two-dimensional signal processing in FMCW radars'. According to section 3, I can find some frequency F=1/(13*5*6us), there are two types chirp,one chirp pperiod is T1=65us,the other is T2=78us, then F1=m1*F, F2=m2*F, m1=6, m2=5. According to the conclusion fvmx=m1*m2*F, then

fvmx=5*6/(13*5*6us)=1/(13us),then Vmax=fvmx/2*lamda/4=c/(4*76*10^9*13^(-6)*2)=37.96m/s, but not 3x of the naive max-velocity 3*15.18=45.54m/s.It seems like 45.54/37.96=6/5. I wonder about that.Can you give me any interpretation? Or is there any error in my derivation procedure?

Thanks,

Regards,

Rata

0 Rata Zhang over 5 years ago in reply to Rata Zhang

Expert 2840 points

Can anyone give me an interpretation?

0 Jitendra Gupta over 5 years ago in reply to Rata Zhang

TI__Guru 69960 points

Hi Rata,

Please refer to the processing chain documentation of mmw demo and MMR demo.

And the training materials

https://training.ti.com/ti-automotive-mmwave-sensors-device-overview

Regards,

Jitendra

0 Rata Zhang over 5 years ago in reply to Jitendra Gupta

Expert 2840 points

Hi Jitendra,

Thanks for your reply,I have understood the chinese remainder theorem and how to realize the algorithm to extending the unambiguous velocity.

BR,

Rata

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CCS/AWR1843BOOST: Extending the unambiguous velocity measurement range using the function disambiguateVel