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!