Hi,
I have several questions regarding the Power Detector (PD) parameters described in the user guide.
1)According to the user guide (p.193), the Power Measurement block has an effective dynamic range of approximately 60 dB, and signals below −60 dBFS cannot be measured accurately. However, on pages 198–199, it is stated that the maximum programmable threshold value is 127, corresponding to −133 dBFS.
Could you please clarify how these two statements are reconciled? Specifically, how should thresholds below the effective measurement range be interpreted in practice?
2)On page 198, it is stated that the Power Measurement Duration (PMD) is a 4-bit word that defines the number of samples used by the Power Detector to calculate the average power.
Based on this description, my understanding is as follows:
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The PD receives input samples at a fixed rate (184.32 MHz after the first decimation block, as stated on p.156).
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The PD computes the average power over a number of samples determined by the PMD configuration.
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By configuring the PMD value, the accumulation length for the power measurement is selected.
Is this interpretation correct?
Additionally, the documentation states that PMD must be configured to be less than the gain update counter, while the gain update counter itself must not be less than 50.5 µs. Could you please explain the rationale behind this requirement?
3)On page 199, it is stated that the RxTddPowerMeasurementDuration parameter sets the duration of the power measurement. This appears to overlap with the role of PMD, which defines the number of samples used for power calculation.
Could you clarify the relationship between these two parameters?
In particular, which parameter ultimately determines the effective power measurement window, and how do PMD and RxTddPowerMeasurementDuration interact?
4)After the first decimation block, the sample rate is 184.32 MHz (approximately one sample every 5.43 ns). With a gain update counter set to 50.5 µs, approximately 93,000 samples are available within a single gain update interval.
For PMD values greater than 13, the configured accumulation length appears to exceed the number of available samples within this interval. In such cases:
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How does the Power Detector operate?
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Does it accumulate all available samples within the interval and terminate early, or does it apply some other internal limitation?
Thank you in advance for your clarification.
Best regards,
Jonatha
