noise variance of AWGN calculation

Discussion in 'Wireless & RF Design' started by sohagiut, Nov 1, 2010.

  1. sohagiut

    Thread Starter New Member

    May 5, 2008
    4
    0
    hello,
    i need to calculate the noise variance of AWGN. i have the following info


    Noise power at the receiver:
    Boltzmann’s constant -228.6 dBW/K/Hz
    Bandwidth = 33 MHz 74.4 dB
    Temperature 20 oC = 273K+20K = 293K 24.7 dB
    Noise figure of the LNB 1.0 dB
    Noise power= -128.5 dBW

    i used the following formula
    Gaussian_sigma = 0.5 * sqrt(2) * ( 10^(0.05 * noise_level_dB ) )
    i put -98.5 dBm=noise_level_dB, the results comes 2.8150e-007 as noise variance, this is very low.
    Can anyone tell me where is the mistake.


    thanks in advance

    Reza
     
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