Effect of input-signal statistical property in delta-sigma modulator with non-uniform quantization

In this paper, we provide the simulation results for the noise reduction in the delta-sigma modulator with a non-uniform quantizer under various types of input signals. The delta-sigma modulator employs a non-uniform quantizer and adjusts the spacing of the quantizer referring to statistical properties of the input signal to the modulator. It reduces its quantization noise compared to the delta-sigma modulator with the uniform quantizer at the same number of output values. The simulation results showed that the amount of noise reduction varied from 0.15 dB to 4.9 dB depending on the input signal, while the effect is not limited by the architecture of delta-sigma modulators. Moreover, it is shown that the PAPR of the input signal cannot work as an indicator of the amount of the noise reduction.