MMWCAS-RF-EVM: MMWCAS-RF-EVM Inter-channel Calibration

user6250223

Part Number: MMWCAS-RF-EVM
Other Parts Discussed in Thread: MMWCAS-DSP-EVM,

Hello, Engineers

I am using MMWCAS-RF-EVM+MMWCAS-DSP-EVM to collect signals and perform related processing. I followed TI’s document "mmwave_studio_cascade_user_guide" in section 8.3 for related calibration. I have the following questions and want to consult.
1. Why do we need to calibrate?
2. According to the document, the calibration file "calibrateResults_high.mat" is obtained by processing the data collected by running the fixed script "Cascade_Configuration_MIMO". I would like to ask if the amount of data I collect is much larger than the amount of data collected by running "Cascade_Configuration_MIMO", does "calibrateResults_high.mat" still apply?
3. If I want to process the raw data by myself instead of using the processing method provided by TI, how can I integrate the calibration file "calibrateResults_high.mat" with the data I collected for processing?Can you provide relevant code and guidance documents?
4. I saw some forums mentioned the file "www.ti.com/.../tiduen5.pdf" but the link is not working properly anymore. Can you provide me with a new link to download it? ?

over 5 years ago

0 Cesar over 5 years ago

TI__Guru*** 149204 points

Hi,

Calibration is needed because the antenna traces are not the same length.

Here is the updated link to the document.

Our cascade expert will review your other questions

thank you
Cesar

0 user6250223 over 5 years ago in reply to Cesar

Intellectual 530 points

Thank you for your reply, Cesar.

0 Randy Rosales over 5 years ago in reply to user6250223

TI__Mastermind 18500 points

Hi user6250223,

The amount of data collection (number of frames) does not matter. The calibration is applied on a frame by frame basis across virtual channels.

For creating your own calibration routine or porting ours to another environment, I think the best resource is the Matlab post-processing example code itself. There is also additional documentation that will be released with the next mmWave Studio update. See here for other posts on that same topic:

https://e2e.ti.com/support/sensors/f/1023/t/911681?MMWCAS-DSP-EVM-Would-Calibration-matrix-generated-by-4-chip-cascade-work-for-less-than-4-chips-in-the-same-board-MIMO-USECASE-

Please let me know if that helps.

Thank you,

-Randy

0 user6250223 over 5 years ago in reply to Randy Rosales

Intellectual 530 points

Hello,Randy

Thanks for your help.

From the document you gave, I saw a theoretical introduction on how to use the calibration matrix. I want to know if you need to write the code according to the theory of "signalPrcesssing_userguide_4chipCascade.pdf" when using MATLAB to process the data, or TI has provided it The code that can be used for processing, if TI has provided the relevant code, please specify. (I mean to use the correction matrix to process the actual data after getting the correction matrix)

0 Randy Rosales over 5 years ago in reply to user6250223

TI__Mastermind 18500 points

Hi,

The example Matlab MIMO processing and TX-BF processing chains already include this calibration as part of the processing, just as described in that document. Please reference the mmWave Studio Cascade User Guide (\mmwave_studio_03_00_00_07\docs\mmwave_studio_cascade_user_guide.pdf) for instructions on how to gather this calibration dataset on your specific MMWCAS-RF-EVM board.

Thank you,

-Randy

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MMWCAS-RF-EVM: MMWCAS-RF-EVM Inter-channel Calibration