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https://designers-guide.org/forum/YaBB.pl Design >> Mixed-Signal Design >> How to calculate quantization noise from spectrum https://designers-guide.org/forum/YaBB.pl?num=1292591388 Message started by Julian18 on Dec 17th, 2010, 5:09am |
Title: How to calculate quantization noise from spectrum Post by Julian18 on Dec 17th, 2010, 5:09am Hi all it is just a trivial question. How to compute quantization noise from its spectrum(from 0 to Nyquist frequency)? suppose in matlab I have a variable QN, which is my quantization noise. of course I can do this: Quote:
suppose I also want to calculate that noise power from frequency domain. so Quote:
but this time I always get two-fold the number i get from time domain calculate(QNP1). I know I must have done sth. very silly, so please help me figure it out! Thanks Julian |
Title: Re: How to calculate quantization noise from spectrum Post by Julian18 on Dec 18th, 2010, 2:24am bump |
Title: Re: How to calculate quantization noise from spectrum Post by boe on Mar 3rd, 2011, 4:01am Julian18, You need to use the power over the full spectrum, i.e. Code:
B O E |
Title: Re: How to calculate quantization noise from spectrum Post by ontheverge on Mar 8th, 2011, 4:38pm 1. make sure coherent sampling 2. q_noise_tot = sum(10^(x/10)) % add up over all non-DC, non harmonic bins. u can convert tot q noise by 10*log(q_noise_tot) |
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