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CSI Position RRS feed

  • Question

  • We are using Sora to get the Channel State Information (CSI) in the
    802.11a mode and our question is that the CSI does not seem to be a
    continuous curve when we plot it out and we were wondering if there
    are ways to restore the continuity of the CSI.



    In our project, we just need the amplitude of the CSI, so we obtain
    the CSI by averaging the absolute values of the signal on each
    subcarrier when we are using BPSK. When we plot the CSI, the figure
    looks like the following:







    As the figure suggests, the CSI has two parts with some 0s in between
    which are the idle subcarriers. However, the two parts do not seem to
    be of the “natural” order. After we swap them, the figure looks like
    the following:







    which appears to be better in the sense that it looks like a
    continuous function. However, the swapping is a completely arbitrary
    move and we were wonder what we should do to relocate the subcarriers
    back to their “natural” spots, possibly by some shifting.



    We checked the Sora code and found that the decoding process actually
    does the same swapping procedure, therefore we suspect that this is
    introduced not by software, but by hardware. But we are really not
    sure.



    Any help is greatly appreciated.  Thanks!
    Tuesday, June 30, 2015 6:46 PM