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AWR1642BOOST: Can I start Tx2 in the middle of time that Tx1 is operating?

Peter010
Genius 4165 points
Part Number: AWR1642BOOST
Other Parts Discussed in Thread: AWR1642, AWR1243, AWR1443

Hello there

I want to start the Tx2 at the time that Tx1 is in its half way of operating. For example the chirp length is 20us. Tx1 starts at 0us, and Tx2 starts at 10us.

Based on my understanding of  mmWave chip, I can divide the 2 chirps into 4 chirps, as showing below. However, by doing so, in the transmitter side, I need to set the 2Tx with two different chirp configuration and start to transmit at the same time. In the receiver side, I need to switch the reference signal from one to another. Do you think it is doable? Beside this method, can I just set configuration for 2 chirps and start the Tx1 and Tx2 with half chirp length delay?

Thanks

Xining

  • 0
    TI__Mastermind 22155 points
    Hello,
    This scheme seems interesting. While we give more thought on how to do this scheme on our device.
    Can you please tell if you are seeing advantages of chirping this way ?

    Thanks,
    Raghu
  • 0 in reply to Raghunandan Kamath
    Genius 4165 points

    Hi Raghu

    This is the time staggered FMCW waveform, which allows both Tx1 and Tx2 transmit simultaneously. In the receiver, three beat frequencies would be received. However, since the IF bandwidth is up to 15MHz for mmWave chip. So the two higher beat frequency can be attenuated. By doing so the PRT can be reduced and the maximum Doppler velocity can be increased, compared with normal TD MIMO.

    Xining

  • 0 in reply to Peter010
    TI__Expert 4720 points

    Hi Xining. 

    'Time staggered FMCW' is an interesting concept! Thanks for telling us about it. 

    Unfortunately, the AWR1642 (and AWR1443 and AWR1243) only has a single 'frequency ramp synthesizer' within it, and as such both Tx1 and Tx2 would have the same transmit frequency (and hence the same ramp). 

    However, it is possible to use two AWR1642 with a delayed hardware trigger between them to achieve the chirp pattern that you are looking for.  Let us know if that would suffice.

    Regards,

    Anil 

  • 0 in reply to Anil Mani
    Genius 4165 points
    Thanks for your reply.