An Energy-Efficient and Noise-Tolerant Recurrent Neural Network Using Stochastic Computing

Recurrent neural networks (RNNs) are widely used to solve a large class of recognition problems, including prediction, machine translation, and speech recognition. The hardware implementation of RNNs is, however, challenging due to the high area and energy consumption of these networks. Recently, stochastic computing (SC) has been considered for implementing neural networks and reducing the hardware consumption. In this paper, we propose an energy-efficient and noise-tolerant long short-term memory-based RNN using SC. In this SC-RNN, a hybrid structure is developed by utilizing SC designs and binary circuits to improve the hardware efficiency without significant loss of accuracy. The area and energy consumption of the proposed design are between 1.6%-2.3% and 6.5%-11.2%, respectively, of a 32-bit floating-point (FP) implementation. The SC-RNN requires significantly smaller area and lower energy consumption in most cases compared to an 8-bit fixed point implementation. The proposed design achieves a higher noise tolerance compared to binary implementations. The inference accuracy is from 10% to 13% higher than an FP design when the noise level is high in the computation process.