Document Type : Research article

Authors

Reliable and Smart Systems Lab (RSS), Shahid Bahonar University of Kerman, Kerman, Iran

Abstract

Stochastic computing (SC) method is a low-cost alternative to conventional binary computing, which processes digital data in the form of pseudo-random bit-streams and because of its highly redundant encoding format, bit-flip errors have a slight effect on the signal final value. As a result, this computational method is used for fault-tolerant digital applications. In this paper stochastic computing has been chosen to implement 2- dimensional discrete wavelet transform (2-D DWT) as a case study. The performance of this circuit is analyzed through two different faulty experiments. The results show that stochastic 2-D DWT outperforms binary implementation. Although stochastic computing provides inherent fault tolerance, we proposed four structures based on dual modular redundancy to improve the stochastic computing reliability. Improving the reliability of the stochastic circuits with the least area overhead is considered the main objective in these structures. The proposed methods are applied to improve the reliability of stochastic wavelet transform circuits. Experimental results show that all proposed structures improve the reliability of stochastic circuits, especially in extremely noisy conditions where fault tolerance of SC is reduced.

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