DeltaSigma CONVERSION DEVICE, PROGRAM AND METHOD FOR OPTIMALLY DETERMINING CONTROL VALUE OF QUANTIZER

摘要

PROBLEM TO BE SOLVED: To provide aΔΣconversion device, program and method for optimally determining a threshold xkand an output value qkof a quantizer so as to reduce quantization noise. SOLUTION: TheΔΣconversion device 1 includes: aΔΣconverter 10 including a non-uniform quantizer; an oscillation detection section 13 for detecting oscillation in the output value qk(k=1, 2, ..., N, N: quantization level) from theΔΣconverter; and a control section 14 for controlling the threshold xkand the output value qkfor the non-uniform quantizer of theΔΣconverter by using the oscillation detection section. The control section includes: a maximum output value determining means which varies the threshold xkand the output value qkof the non-uniform quantizer to detect a maximum output value qN-MAX, that is not oscillated, using the oscillation detection section; and a control value determining means for setting the threshold xkto an intermediate value of output values qkto qk+1while fixing the maximum output value qN-MAX, and then setting the output value qkto a center of gravity weighted with a probability density function of an amplitude value of an input signal to theΔΣconverter in a section Qkof thresholds xk-1to xk. COPYRIGHT: (C)2011,JPO&INPIT