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Original question:
AWR1843: Is there a possibility of BPM transmission for 3Txs
Hi ,
I have browsed the forum to look for a minimal example which uses an x degrees beamwidth for one single frame using all the 3 antennas. I think this is frame-based beam steering
It turned out that there are several examples for the BPM mode but not for the phase shifter settings. My confusion is there are many places to change but there is no way for me to verify I'm doing this correctly. Appreciate it any explanations for this.
1 st attempt. Phase Shifter in sensor Config.
I have followed the following formula the below document to generate the phase shift values for +20 degrees and put them into the Phase Shifter in sensor Config.
2nd attempt. BPM config tab
Here I have tried the same formula but divided it by 5.625. I wanted all the chirps in the frame to have this configuration.
Q1: First thing is I don't see much SNR gain for the objects in 20 degrees compared with TDM-MIMO. Am I doing something wrong?
Q2: Is there a way to get the beam width, I assume 20 degrees is the boresight angle.
Q3: What changes need to be done for the signal processing pipeline when it comes to AoA estimation to calculate azimuth and elevation angle?
Q4: What will be the angle resolution in this mode?
Thank You!
Isura
Hi Cesar,
Thanks a lot for the information. Ihave few other questions.
1) About the antenna indexing. I do understand that we add the pahse shift to the the transmitter closests to the receiver. In this case Tx3 .
I have a setup where two objects are present. Range and angle information of the objects are correct in both experiment
As you have mentioned, I have reversed the phase shift values for AWR1843 so that the phase shifter line became like this.
ar1.SetPerChirpPhaseShifterConfig(0, 0, 45,23, 0)
The detection results looks like this.
However, for the original code you have provided(for AWRAOP), detection results are as follows.
ar1.SetPerChirpPhaseShifterConfig(0, 0, 0,23, 45)
You can see the SNR has a clear improvement. I don't know any other way to interpret this result but seems to me either I'm doing something wrong from my side or there seems to be an issue with the configuration file.
2) LDO Bypass operation, I can see the script does it, do I have to do anything to the bord to enable this.
3) FOr MIMO radar processing angle estimation, if we enable 3 Tx and 4 Rx, w ehave virtual antenna array of 12. So we can select 8 for the azimuth plane and 4 for the elevation.
For Beam steering, we have only 4 Rx since the 3 Tx transmit simulteneously. My confusion is how to select antennas for angle estimation.
We can take 4 rx as azimuth processing, what about the elevation processing, we require to have at least two antennas to do that.
Appreciate it any help related to this.
