Roundoff and coefficient quantization noise of pipelined scattered look-ahead filters with decomposition

Abstract

Unified statistical coefficient quantization (SCQ) and round-off noise (RON) analysis for a fixed-point arithmetic model is applied to scattered look-ahead (SLA) with power-of-two decomposition filters. Assumptions under which noise power due to SCQ is the same as RON under single length accumulation are derived. Analytical results are derived for first-and second-order direct-form (DF) and minimum roundoff noise (MRON) basis filters which contradict previous claims. The application of SLA is shown to slightly increase noise for poles near z=0 and to generally decrease noise near mod z mod =1, except that the noise of DF SLA increases greatly for small regions near mod z mod =1 due to closely spaced poles. >