Multistage Multirate Transfer Function Automated Synthesis Using Hybrid Sampling Strategy-Based Differential Evolution

Abstract

Modern digital systems require one or more frequency shaping modules that realize certain transfer functions, usually in the form of digital filters. Breaking up the design into multiple stages results in reducing the implementation area and power consumption. However, there is no well-defined automation methodology to design an optimum multistage multirate filter. This article proposes a new design flow automation tool using a hybrid sampling strategy-based differential evolution (HSS-DE). The user specifies the inputs and outputs of the system, including the input spectrum, the sample rate change, the magnitude and phase responses, and the required signal-to-noise ratio. The tool uses this information to generate a solution indicating the number of stages and the filters' specifications for each stage such that the generated architecture satisfies the user requirements. We compared the proposed tool to subsystems designed by experts in the ASIC industry. Several case studies are presented to demonstrate the proposed tool's efficiency in different design problems. The case studies include decimation filters for sigma-delta (ΣΔ) analog-to-digital converters (ADCs) and interpolation filters for wideband transmitters such as wideband code division multiple access (WCDMA). The case studies' results indicate that the proposed design automation flow reduces the design time remarkably, in addition to reducing the implementation in all cases.