Bugzilla – Bug 2465
Microwave oven model has overlapping subbands
Last modified: 2016-08-06 20:35:12 EDT
Created attachment 2519 [details]
MicrowaveOvenSpectrumModel5MhzInitializer and MicrowaveOvenSpectrumModel6MhzInitializer create subbands with distance of 5Mhz and 6MHz respectively. The problem is that they are 10Mhz and 12Mhz wide, while they should be 5Mhz and 6Mhz wide so they don't overlap.
This results in 3dB (2 times) difference: each subband contributes its PSD twice.
Attached is a scenario (simplified spectrum example with ALOHA etc. removed) that places microwave oven and spectrum analyzer in the same point in space. Plots and patch follow.
Created attachment 2520 [details]
Gnuplot script to plot test scenario results
Script plots PSD in dBm so it can be compared to PSD in the article "Microwave oven signal modeling" referenced in source code.
Created attachment 2521 [details]
Result plot before patch
Created attachment 2522 [details]
Result plot after patch
Created attachment 2523 [details]
Note that plot has narrower range than plot in the article, but you can compare the value on the center frequency (2.42 Ghz in Fig. 3) or change the model of spectrum analyzer to cover the whole range of frequencies.