Noise Floor Doc

In this video we’ll look and see what a noise floor looks like using the Channelizer 3.4 spectrum analyzer.

Let’s look at just the noise floor without any wi-fi devices in operation. We start the spectrum analyzer and start looking at the view. It looks like there’s quite a bit of activity, but there really isn’t, because you can see in the bottom panel you see the average, and you see the maximum.

If you look in the middle in the top panels, you see that there’s not really much activity there. There’s some around channel 2, and there’s two spikes, one around channel 3 and one around channel 8. We’ll look at those more closely in a moment.

Right now, if we take out the average and the maximum, we can see that it’s just mostly transient activity except for that little bit around channel 2. We put back the average. We can see it builds a little bit over time, but, again, if you look at the middle panel you see that there’s a wave form there that’s clearly not a wi-fi device because of the shape of it. Those two little spikes are fairly steady, but they’re also very low-level signals that we see there around channel 3 and around channel 8.

Now let’s select just channel 2 and zoom in on it and see if we can figure out what it might be. As we look now more closely at channel 2 we can see that the activity there is fairly light. It’s not a very strong signal.

Also, if we look in the middle panel we can see it has kind of a pyramid shape to it. That’s probably going to be a portable phone, something like that. We can check to see if it’s a wi-fi device by selecting the Config Wi-Fi tab and looking at it, and we start the scan. We see, no, there are no wi-fi devices, so clearly that’s not what that is.

Now we go back and select the entire channel. We’ll look again to see what we see out there. So we see just a little bit of activity at channel 2 and the two other small spikes around channel 3 and channel 8.

Now let’s look at the...