@article{3037011,
    title = "Elimination of idle tones by a 2-bit adaptive sigma-delta modulation system",
    author = "Prosalentis, E. and Tombras, G.S.",
    journal = "ETRI Journal",
    year = "2009",
    volume = "31",
    number = "4",
    pages = "393-398",
    issn = "1225-6463",
    doi = "10.4218/etrij.09.0108.0611",
    keywords = "AC signals;  Adaptation algorithms;  Adaptive sigma-delta modulation;  Dc signals;  Extended dynamics;  First-order;  High SNR;  Idle tones;  Look-ahead;  Multiplicative errors;  Noise power;  Quantizers;  Sigma-delta;  Sigma-delta modulation;  Simple system;  System operation, Analog circuits;  Computer simulation languages;  Modulation;  Modulators, Delta sigma modulation",
    abstract = "The operation of a first-order 2-bit adaptive sigma-delta modulation system is described and discussed in this paper. The system operation is based on the combination of both "memory" and "look-ahead" estimation in the employed step-size adaptation algorithm of the basic quantizer. In comparison to simple systems and other adaptive sigmadelta systems, computer simulation results show that these features of the described system are responsible for the high SNR values and the extended dynamic range achieved for AC signals as well as the noise power reduction of almost 10 dB and the complete elimination of the idle tones for DC signals. However, such an advantageous performance requires the least possible multiplicative error accumulation, and this cannot be achieved without analog circuits of the highest possible accuracy."
}