single loop delta sigma modulators

I am reading the paper:
"Optimal parameters for single loop Delta sigma modulators".
I am confused on the formula used for SNR and DR (c.f. equation 2 and 3 in the paper ).
The value of SNR does not depend on the value of quantization bits according to the formula. But calculated values of SNR in the Table 1( for one bit quantizer) and table 2(for 4 bit quantizer) show different values of SNR for same valus of oversampling ratio and order of the loop.
I request u to please explain it to me, and suggest any references .

I am reading the paper:
"Optimal parameters for single loop Delta sigma modulators".

I am confused on the formula used for SNR and DR (c.f. equation 2 and 3 in the paper ).
The value of SNR does not depend on the value of quantization bits according to the formula. But calculated values of SNR in the Table 1( for one bit quantizer) and table 2(for 4 bit quantizer) show different values of SNR for same valus of oversampling ratio and order of the loop.
I request u to please explain it to me, and suggest any references .


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