A shinny new NI PXI system *drool* Some links for reference: http://digital.ni.com/public.nsf/allkb/3003B0E10C3C71E286256CAD0070FCAA http://zone.ni.com/devzone/cda/tut/p/id/4731 http://zone.ni.com/devzone/cda/tut/p/id/3592 http://digital.ni.com/public.nsf/websearch/C074C33F4DE3FA5186256D3D007788DA?OpenDocument
Just got myself a cozy corner in a lab (which has secure digital doors). Set up the shinny new computer on friday, and we will be moving the VSA in on monday.. Can’t wait to start doing stuff!
Power spectrum is very useful in seeing what a channel are in use. Due to the volume of notes on the Power Spectrum it will not be replicated here.
Another important concept linked to DFT/FFT is the use of windowing functions.
First of all, we see that DFT/FFT uses a finite number of samples, and what happens is we are just cutting off samples after a certain number, and feed that into the FFT. When we look at it, this is the same as multiplying the samples with a rectangular window that is 1 inside N, and 0 elsewhere.
DFT and FFT stand for Discrete Fourier Transform and Fast Fourier Transform respectively.
Gibb’s Phenomenon is also know as ringing artifact. It’s where a sampled signal shows small oscillations on the edges when they are reconstructed, wikipedia shows some very good examples
This entry focuses on a few implementations of CR published in various top journals and conferences.
The radio spectrum is divided into the following:
| Frequency Designation |
Frequency Range |
| Ultra Low Frequncy (ULF) | < 3Hz |
| Extremely Low Frequency (ELF) | 3Hz – 3kHz |
| Very Low Frequency (VLF) | 3kHz – 30kHz |
| Low Frequency (LF) | 30kHz – 300kHz |
| Medium Frequency (MF) | 300kHz – 3MHz |
| High Frequency (HF) | 3MHz – 30MHz |
| Very High Frequency (VHF) | 30MHz – 300MHz |
| Ultra High Frequency (UHF) | 300MHz – 3GHz |
| Super High Frequency (SHF) | 3GHz – 30GHz |
| Extremely High Frequency (EHF) | 30GHz – 300GHz |
| Submilimeter | 300Ghz – 3THz |
No reseach is complete without the use of some fancy weird terminology! To this end, the IEEE Standard Definition and Concepts for Dynamic Spectrum Access (IEEE Std 1900.1) is a gold mine haha, all kinds of terminologies people have come up with. This post will highlight a few that are funny, or useful to this project. This is just a water down, near laymen terms version of the standard, for personal quick reference only
Carrying on from the last post, seems there is a 802.22 standard that seems to be out (as the document below sugests), but its not listed in the IEEE standards library anywhere, maybe its very very new and just printed