A comparison of the effects of component nonidealities on the performance of analog and digital LMS adaptive noise cancellers

The effects of the nonidealities of the components used in the implementation of analog and digital adaptive noise cancellers are compared. It is shown that the effects of implementation differ significantly from those encountered in ideal considerations or those in which the added circuit noise is assumed to have a zero mean distribution. Analytical expressions are presented to show that the most deleterious effects found in analog implementations are caused by the errors found in the weight integrators and the input multipliers. The effects of input quantization, quantization of the weights, effects of roundoff accumulation, and the effects of the digital residual error are considered for digital implementations.