can anyone tell me how to calculate noise variance (sigma^2/2),if noise power spectral density is -162dBm/hz. Noise is additive white circularly symmetric gaussian complex noise. what is relation between noise variance and power spectral density? Thanks

# how to calculate noise variance from noise power spectral density value

Started by ●January 28, 2011

Reply by ●January 28, 20112011-01-28

>can anyone tell me how to calculate noise variance (sigma^2/2),if noisepower spectral density is -162dBm/hz. Noise is additive white circularly symmetric gaussian complex noise. what is relation between noise variance and power spectral density?> >Thanks > > >hint: what is the relation between noise variance and noise power? (assuming the process is ergodic)

Reply by ●January 28, 20112011-01-28

On Jan 28, 9:29�pm, rit <u...@compgroups.net/> wrote:> can anyone tell me how to calculate noise variance (sigma^2/2),if noise power spectral density is -162dBm/hz. Noise is additive white circularly symmetric gaussian complex noise. what is relation between noise variance and power spectral density? > > ThanksThe area under the graph.

Reply by ●January 28, 20112011-01-28

rit schrieb: what is relation between noise variance and power spectral density?> > Thanks > >Parseval's theorem

Reply by ●January 30, 20112011-01-30

On Jan 29, 6:35�am, Sebastian Doht <seb_d...@lycos.com> wrote:> rit schrieb: > what is relation between noise variance and power spectral density? > > > > > Thanks > > Parseval's theoremSame as the area under the spectral density curve.

Reply by ●January 30, 20112011-01-30

HardySpicer schrieb:> On Jan 29, 6:35 am, Sebastian Doht<seb_d...@lycos.com> wrote: >> rit schrieb: >> what is relation between noise variance and power spectral density? >> >> >> >>> Thanks >> >> Parseval's theorem > > Same as the area under the spectral density curve.Of course but when I was a student I could better understand things which I could mathematically derive myself. So Parseval's theorem tells why one should compute the area under the graph. Of course this assumes the opener really wants to understand rather than looking for cheap and easy answers.