Holistic Biquadratic IIR Filter Design for Communication Systems Using Differential Evolution

Alexander Melzer,Andreas Pedross,Manfred Mücke

doi:10.1155/2013/741251

Abstract

Digital IIR filter implementations are important building blocks of most communication systems. The chosen number format (fixed-point, floating-point; precision) has a major impact on achievable performance and implementation cost. Typically, filter design for communication systems is based on filter specifications in the frequency domain. We consider IIR filter design as an integral part of communication system optimisation with implicit filter specification in thetime domain(via symbol/bit error rate). We present a holistic design flow with the system's bit error rate as the main objective. We consider a discrete search space spanned by the quantised filter coefficients.Differential Evolutionis used for efficient sampling of this huge finite design space. We present communication system performance (based on bit-true simulations) and both measured and estimated receiver IIR chip areas. The results show that very small number formats are acceptable for complex filters and that the choice between fixed-point and floating-point number formats is nontrivial if precision is a free parameter.

Highlights

IntroductionFilters are building blocks removing unwanted signal components (often, but not exclusively, specified in the frequency domain)
In signal processing, filters are building blocks removing unwanted signal components
Though, that under the presence of channel noise and nonlinearities, a filter optimising the overall bit error rate (BER) can be implemented with a magnitude response significantly different than the specification of the matched filter

Summary

Introduction

Filters are building blocks removing unwanted signal components (often, but not exclusively, specified in the frequency domain). The ultimate goal is rarely specifiable in the frequency domain but is reflected in a more complex measure. Implementation of digital filters requires identification of arithmetic units to be implemented, the choice of a specific number format for each arithmetic unit, and quantisation of filter coefficients. These actions alter the filter characteristics and, if not foreseen in the design process, can have a severe impact on the system’s performance

Methods

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Discussion

Conclusion