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MMWCAS-RF-EVM: AWR2243 cascaded board - How many frames per seconds?

Abdelrahman Taha
Prodigy 60 points
Part Number: MMWCAS-RF-EVM
Other Parts Discussed in Thread: AWR2243, , MMWCAS-DSP-EVM

Hello,

I am using the TI AWR2243 cascade board with the MMWCAS-RF-EVM (Rev-E) connected to the MMWCAS-DSP-EVM.

mmWave studio software: version 02_01_01_00

Firmware: mmwave_dfp_01_02_06_03

I am using the MATLAB examples for the TXBF and TDM MIMO modes. Let a frame denote the 4D matrix captured in a given time interval. I want to calculate exactly the frame interval or the number of frames per second. I want to control the frame rate with good accuracy. I spent some time and effort on my end reading the MATLAB scripts to understand the configuration parameters and how they can control the frame rate.

For the TXBF mode, for a burst-based beam steering frame structure, the 4D matrix is no samples per chirp x no chirp repetitions per loop x no of receivers (RXs) x no of steering angles. For the TDM MIMO mode, the 4D matrix is no samples per chirp x no chirp loops x no of receivers (RXs) x no of transmitters (TXs).


I have questions on two parameters:

A) Duty cycle: In the TXBF mode, in the chirpprofile_TXBF_USRR.m MATLAB script, line 75, what does the variable params.Dutycycle represent?

  1. Does it account for the OFF duration before and after the chirp ADC sampling time? or does it account for the OFF duration between bursts (Frame-based beam-steering) or loops (chirp-based beam-steering)? or there is another definition?
  2. Does the duty cycle follow the same definition in the TDM MIMO mode? or is it defined differently in the TDM mode? What is its definition in the TDM MIMO mode?





B) Inter_Frame_Interval: In the TDM MIMO mode, in the Cascade_configuration_MIMO.lua LUA script, line 87, what does the variable Inter_Frame_Interval represent?

  1. Does it represent the OFF duration between frames (the time interval between the end of one frame and the start of the next frame)? or does it represent the frame repetition period (the time interval between the ON start of one frame and the ON start of the next frame)? or there is another definition?
  2. Based on the answer to the previous question, and knowing the frame ON duration, how small can we set the OFF duration between frames? Is there any hardware constraint involved? If any, what are these constraints?

Thank you for your help!







  • 0
    TI__Guru*** 149044 points

    Hi,

    The concept of frame duration is same for single chip or cascade systems.

    Let me know if you are familiar with the concept for single frames or if our team should provide a short summary for single chip case

    Thank you

    Cesar

  • 0 in reply to Cesar
    Prodigy 60 points

    I think I will need the help of the team.

    I am a bit familiar with the concept of the frame structure that was explained in the manual documents but I would definitely appreciate the help of the team in finding the answers to the questions above either by supporting a short summary that has the answers to these questions or by providing direct answers to these questions. Any convenient method works well for me. I could not find the answers in the manual documents I have.

    Thank you! Appreciated.

  • 0 in reply to Abdelrahman Taha
    TI__Guru*** 149044 points

    Hi,

    In Cascade_configuration_MIMO.lua, "Inter_Frame_Interval" is used to initialize the Frame Period. The Frame Period has to be such that there is sufficient time for two things to happen before the next frame starts

          1) There is sufficient time for chirping (this is also called "Active Time")

          2) There is sufficient time to process the data after chirping is complete.

    Thank you

    Cesar

  • 0 in reply to Cesar
    Prodigy 60 points

    Hello,

    Thank you for your answer! I need to calculate these two time intervals then to be able to control the frame rate.

    Q1) Is the first interval, the "Frame Active Time" interval, formulated in the TDM MIMO mode as follows?

    let's define the "Chirp Time Interval" as follows. Chirp Time Interval = Chirp TX Idle Time + Chirp Ramp End Time 


    Therefore, is the following formulation correct? 
    Frame Active Time =  Chirp Time Interval x No. Chirps per Block (Number of Transmitters) x No. Blocks?




    Q2) How can I calculate/formulate the second interval in the Frame Period, the sufficient time to process the data after chirping is complete?


    Q3) In the TXBF mode, in the chirpprofile_TXBF_USRR.m MATLAB script, line 75, what does the variable "params.Dutycycle" represent?

    Does it represent the non-active duration around the chirp ADC sampling time (the "Chirp Active Time")? or does it represent the non-active duration between bursts (Frame-based beam-steering)? or there is another definition?



    Q4) Does the duty cycle in the TXBF mode follow the same definition in the TDM MIMO mode? or is it defined differently in the TDM MIMO mode? If yes, what is its definition in the TDM MIMO mode?

    Thank you for your help!

    ----

    The images displayed in this message are from the TI manual documents related to the chirp and frame configurations.

  • 0 in reply to Abdelrahman Taha
    TI__Guru*** 149044 points

    Q1 - Yes this is correct

    Q2 - The Processing time depends on how long the processing takes after 1D FFT is complete. You would need to benchmark the processing time to estimate it

    Q3 - Yes, params.Dutycycle is used to compute the burst periodicity

    Q4 - For TDM MIMO the burst periodicity is defined in a different way. It is defined in the JsonParser.m

    Thank you

    Cesar