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CCS/AWR1843BOOST: There are several questions in the <TI mmWave Labs Medium Range Radar – Developer’s Guide> documentation that need to be answered.

user5740064
Intellectual 500 points
Part Number: AWR1843BOOST

Tool/software: Code Composer Studio

1.effective chirp time = (number of ADC samples) / (ADC sampling frequency) ,If not, what is it?

2.bandwidth = (ramp end time) * (frequency slope),Why is the bandwidth of USRR 3456? If not, what is it?

3.frame length = (chirp idle time + chirp ramp end time) * (number of chirps per profile),Why is the frame length of USRR 10.5?

For a slow chirp, have you considered its chirp idle time?

If not, what is it?

4.How is the memory requirement calculated?




  • 0
    TI__Mastermind 22155 points
    Hello Cheng,
    You have rightly pointed out the mistakes in the documentation. We will correct these in our next version of the document/release.

    A1.effective chirp time = (number of ADC samples) / (ADC sampling frequency) . MRR: 55us USRR(30m): 40.96us

    2.bandwidth = (ramp end time) * (frequency slope) . MRR: 240MHz USRR (30m): 2475MHz

    3.frame length = (chirp idle time + chirp ramp end time) * (number of chirps per profile) MRR: 16.64m USRR(30m) : 25.088m

    For slow chirps we dither the IDLE time . Please refer to the "CHIRP_MRR_1_IDLE_TIME_VAL" in the MRR configuration.

    A4: (number of chirps in frame ) *(number of samples per chirp) * (sample width 2byte I and 2 Byte Q) * (Number of Rx)


    Thanks,
    Raghu
  • 0 in reply to Raghunandan Kamath
    Intellectual 500 points

    Thank you for your answer,I have sorted out the table parameters, and there are still a few questions for you to answer.

    1.max range = ((max IF) * (speed of light))/(2*(frequency slope)), if not,what is it?

    2.As shown in the figure below, what does this maximum and minimum distance represent?

    I look at the structure parameter definition says(minimum range at which a target is detected ( in xyzOutputQFormat precision).).

    How do I understand it?

    3.I know some parameters of the formula in the figure below,Could you tell me how to use this formula?Or should I fill in those parameters to estimate my maximum distance?Can the following parameters be known from the data manual?

    All the formulas above, which is the formula for calculating the maximum range of the radar?

  • 0 in reply to user5740064
    TI__Expert 4720 points

    Hi,

    The minRange, and the maxRange determine the limits for CFAR-based detection. In the MRR use-case, we set the minimum range to 0.5 meters (with 7 bits of precision), and the maximum range to ((0.9*num_ADC_samples) * (speed of light))/(2*(bandwidth)). The factor 0.9 is necessary because the remaining 10 % of the IF contains the transition bands for the various low pass filters.

    I didn't understand your second question. The 'radar equation' (the formula that you've shown) can be used to estimate the maximum distance at which a radar can detect a target (with a certain frame-time). However, you also need to create a 'chirp design' that can achieve this maximum range, which is why we use the ((0.9*num_ADC_samples) * (speed of light))/(2*(bandwidth)) formula.

    Regards

    Anil

    Note : Edited to correct a formula.

  • 0 in reply to Anil Mani
    Intellectual 500 points

    Thank you for your answer. If the maximum distance is calculated according to the formula you provided, the maximum distance is 337.5 meters in the sub-frame of MMR, which is inconsistent with the 150 meters distance you provided.

    Looking at the description in the figure above, when the RCS value is 10 square meters, it can be detected at 150 meters. If I understand it correctly, it should be calculated by some formula, which may be related to the radar equation. Right?

  • 0 in reply to user5740064
    TI__Expert 4720 points
    Hi Cheng,

    There was a mistake in the formula. Please check my message again.

    Regards
    Anil