Note: In earlier versions of the 802.11 standard, the (BCC) OFDM example was given in Annex G. However, an error existed (e.g. in IEEE Std 802.11-2007) in that the FCS was incorrect (see link or search online for "IEEE 802.11-09/0042r0"). The WiFi (802.11) standards documents are free to download from the IEEE webpages (see, for example, here). (Sadly, you are required to register first, which I would describe as irritating and pointless). ...
Updated 31st October 2018 at 08:02 by weetabixharry
In Part I of this blog, we saw that we can construct two partially correlated signals, x_{1}(t) and x_{2}(t), as: ...
Note: This blog is split into two parts because edaboard limits the number of pictures and equations per blog. The second part can be found here: [link]. Introduction It is often useful to be able to generate (real or complex-valued) signals with specific cross-correlations. In the simplest case, this means we want to produce two signals with a specified cross-correlation (and specified powers). Or, in the general case, it means we want to specify an ...
Updated 7th December 2014 at 20:01 by weetabixharry
I was recently asked how to estimate the frequency of a noisy sine wave over a short capture. In this context, 'short' means the total capture duration relative to the period of the sine wave. So we may have, at most, a few periods of the sine wave (or, at worst, less than one period). Here is an example (download raw data: sine_data_40k.zip): Clealy, there is less than ...
Updated 20th December 2014 at 12:32 by weetabixharry
We often plot some data on a graph and wonder if there might be a simple mathematical function to describe what we see: In many cases, a polynomial approximation would be particularly useful. That is, we want to describe the line in the form: ...
Updated 2nd November 2014 at 21:37 by weetabixharry