About dw1000 los cir power

Wireless Connectivity Ultra-Wideband
1

I have a question regarding the CIR signals obtained through DW1000 measurements. In two different LOS (Line of Sight) scenarios, one is in an open free-space area where the LOS CIR signal has no reflected signals, and the other is assumed to be in a narrow corridor or tunnel where there are multiple reflections in the LOS scenario.

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  1. In two different LOS (Line of Sight) scenarios, what differences would there be in the CIR (Channel Impulse Response) of the received LOS signal?
  2. Is it the case that the total signal power in one scenario is less than in the other? Is it because the second scenario has multiple reflected multipath and scattered signals?
  3. In which scenario does the signal have a larger maximum value? What is the reason?
  4. Is the difference between the two signals manifested in the multipath part after the first path index?
  5. What else can distinguish the signals in the two scenarios? I have images from a document I read, such as figures a and c.
2

This reads like a homework question.

  1. The CIR leading edges will be the same, for an open area the initial spike will drop off faster and cleaner than the one in an environment with reflections.
  2. The LoS signal will be the same for the two, reflections won’t have any impact on the line of sight signal path. Since reflections can’t contain a negative amount of power the one with reflections must have more total power than the one without reflections.
  3. See 2.
  4. See 1. Reflections are by definition after the first signal and so will be after the first path.
  5. You can characterise the rate of drop off and number of peaks after the initial one to get an indication of how reflective the environment is. But generally assuming the first path is LoS and is correctly detected you don’t care much about what happens afterwards, you have the measurement you normally care about. At least for ToF range measurement applications that is the case.
    NLoS is very different as the chart shows. For that you can look at the first path power and ratio between first path and total power to get an indication of whether the signal is blocked.
3

This is a question I encountered while reading a paper. Thank you for your reply.