On the design of LDPC-based Raptor codes for single carrier Internet of Things (SC-IoT)

Abstract

In this paper, we propose new Raptor codes suitable for uplink Internet of Things using single carrier transmission technique (SC-IoT) with low density parity check (LDPC) codes as the precode, called LDPC-Raptor codes. The utilization of LDPC as the precode is to guarantee high capability of error correction for better Raptor codes performance while keeping the computational complexity low. Raptor Codes are preferable for SC-IoT because of their flexibility with both fixed/non-fixed rate (rateless) and simplicity in decoding. The LDPC-Raptor codes is designed (sub)-optimally using Extrinsic Information Transfer (EXIT) chart to meet requirements of SC-IoT. We evaluate the performance of the proposed LDPC-Raptor codes to achieve the Shannon capacity over Binary Erasure Channels (BEC)-based equivalent additive white Gaussian noise (AWGN) and frequency-flat Rayleigh fading and show that LDPC-Raptor codes provide significant contributions than Luby Transform (LT) codes for SC-IoT.