Nonlinear Digital Filters

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INTRODUCTION

WHY ARE DIGITAL FILTERS ASSOCIATED WITH NONLINEARITIES?

Nonlinearities are associated with digital filters mainly for implementation reasons and are tailor-made for many applications.

Nonlinearities due to implementation reasons

The most common nonlinearities associated with digital filters due to implementation reasons are quantization, saturation and two’s complement. Quantization occurs because of the finite word length effects. Saturation occurs because of a constraint being imposed on the maximum bound of signals. Two’s complement operation occurs because of the overflow of signals to their sign bits. Although most computers these days are more than 64 bits—and floating point arithmetic is employed for the implementation—the ...