A New Soft-input Hard-output decoding algorithm for Turbo Product Codes

Abstract

Turbo product codes (TPCs) are being considered as a competitive forward error correction scheme for ultra high speed network communication beyond 100Gbps [1], [2]. Conventional soft-input soft-output (SISO) decoders for turbo product codes (TPCs) need to exchange extrinsic soft messages between row and column component decoders. However, the extrinsic information increases the difficulty of hardware implementation. First of all, for a two dimensional message memory, row and column component decoders access soft messages in horizontal and vertical directions, respectively, resulting in potential memory access conflict. Secondly, the computation complexity of calculating the soft extrinsic information is very high. Finally, storing the extrinsic information needs additional memory and updating it frequently increas the decoding latency and power consumption. In this paper, we propose a new soft-input hard-output (SIHO) decoding algorithm for TPCs. The proposed SIHO decoding algorithm requires the exchange of only hard information between row and column component decoders, leading to simpler decoder architectures. Moreover, each component decoder of a SIHO TPC decoder does not generate any soft information. In terms of error correction performance, the SIHO decoding algorithm is in between the SISO and the hard-input hard-output decoding algorithm. It is believed that the SIHO decoding algorithm is a good tradeoff between high net coding gain (NCG) and low complexity implementation.