- TITLE:
-
Express Coefficients in 13-ary, Radix-4 CSD to Create
Computationally Efficient Multiplierless FIR Filters
- AUTHORS:
- J. O. Coleman
- ABSTRACT:
- A two's complement DSP signal can be multiplied by a
fixed coefficient using an adder tree operating on
input shifts corresponding to nonzero coefficient
bits. Alternatively, the signed bits of a canonical
signed-digit (CSD) coefficient representation specify
an add/subtract network, with one third fewer terms
required on average. That well-known approach is
generalized here to a radix-4 CSD system that turns
out to save 36% relative to conventional CSD in the
FIR-filter application but at a per-filter overhead
cost of six small-integer scaling operations that
represent common subexpressions implicitly factored
from the add/subtract network. The approach works for
both direct-form and transposed-form filters and
generalizes easily to other number systems.
- DOWNLOADABLE PREPRINT:
-
PDF preprint (185K),
official
PDF from the The Otaniemi Campus Library, Aalto University, Finland,
- STATUS:
- Presented at the The 15th European Conf. on
Circuit Theory and Design (ECCTD
'01), Espoo, Finland, August 2001.
- DATE OF ENTRY:
-
August 2001.