SUMMARYThis paper presents FIR digital filters based on stochastic/binary hybrid computation with reduced hardware complexity and high computational accuracy. Recently, some attempts have been made to apply stochastic computation to realization of digital filters. Such realization methods lead to significant reduction of hardware complexity over the conventional filter realizations based on binary computation. However, the stochastic digital filters suffer from lower computational accuracy than the digital filters based on binary computation because of the random error fluctuations that are generated in stochastic bit streams, stochastic multipliers, and stochastic adders. This becomes a serious problem in the case of FIR filter realizations compared with the IIR counterparts because FIR filters usually require larger number of multiplications and additions than IIR filters. To improve the computational accuracy, this paper presents a stochastic/binary hybrid realization, where multipliers are realized using stochastic computation but adders are realized using binary computation. In addition, a coefficient-scaling technique is proposed to further improve the computational accuracy of stochastic FIR filters. Furthermore, the transposed structure is applied to the FIR filter realization, leading to reduction of hardware complexity. Evaluation results demonstrate that our method achieves at most 40dB improvement in minimum stopband attenuation compared with the conventional pure stochastic design. key words : FIR digital filter, stochastic computation, computational accuracy, digital circuit implementation
This paper proposes a new unified framework for the adaptive IIR band-pass/band-stop filtering for detection and enhancement/suppression of an unknown narrowband signal immersed in a broadband signal. In most of the conventional methods, which are well-known as the adaptive notch filtering, the adaptive band-pass/band-stop filter is restricted to a low-order transfer function. On the other hand, our proposed method can be applied to arbitrary high-order band-pass/band-stop transfer functions in a simple manner. We derive this simple adaptive mechanism with the help of the frequency transformation and its block diagram representation. In addition, we prove that this result includes the conventional all-pass-based adaptive notch filters as special cases. Moreover, we demonstrate a significant property that the use of high-order adaptive band-pass/band-stop filters yields much better signal-to-noise ratio (SNR) improvement than the conventional low-order filters.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.