Elimination of idle tones by a second order 2-bit adaptive sigma delta modulation system

摘要

We investigate the operation and implementation aspects of a second order 2-bit adaptive sigma–delta modulation system that offers complete elimination of the idle tones without dithering as needed by various other adaptive and simple sigma delta schemes. Performance comparisons made by computer simulation indicate that this advantageous feature together with the enhanced performance stability is due to the combination of both “memory” and “look-ahead” estimation of the employed step-size adaptation algorithm.