Hardware Implementation Aspects of a Syndrome-based Neural Network Decoder for BCH Codes
Emmanouil Kavvousanos, Vassilis Paliouras · 2019
Deep-Learning-based Decoders have been recently introduced for use with short-length codes. They have been found to act as a Soft-Decision-Decoding method achieving near Maximum-Likelihood error correcting capability. However, Deep-Learning decoding methods are hard to implement as they normally require millions of operations for inference. In order for Deep-Learning decoding to be a competitive candidate for practical applications, research effort is required to reduce the computational complexity and storage requirements of the Neural Networks involved. In this work, a structured flow is presented that significantly compresses a trained Syndrome-Based Neural Network Decoder by pruning up to 80% of the network's weights and quantizing them to 8-bit fixed-point representation, with no loss in its BER performance. The attained compressed Neural Network can then be used for inference, by designing specific hardware or by using a generic Deep-Learning hardware accelerator that exploits the compressed structure of the network. The deployment of the DL Decoder in an embedded application is showcased, using the AI Edge platform by Xilinx. To accomplish this, a simple method to obtain a computationally equivalent convolutional layer from a fully-connected one is introduced. Implementation results are provided for the compressed DL Decoder, regarding throughput rate and BER performance. To our knowledge, this is the first DL decoder in hardware reported.