Spatially Coupled Protograph LDPC-Coded Hierarchical Modulated BICM-ID Systems: A Promising Transmission Technique for 6G-Enabled Internet of Things

Abstract

As a spectral-efficiency technique for unequal error protection (UEP), hierarchical modulated (HM) bit-interleaved coded modulation (BICM) with iterative decoding (ID) has attracted interests in wireless communication community. In this paper, we conduct an investigation on spatially coupled (SC) protograph lowdensity parity-check (P-LDPC)-coded M -ary quadrature amplitude modulation (QAM) HM-BICM-ID systems. We first develop an information-theoretic methodology to calculate (log 2 M )/2 types of constellation-constrained average mutual information (AMI), which can be used to characterize the performance limits of different layers in the HM-BICM systems. We further propose a two-stage design approach to construct a novel type of constellations, called as structural quadrant (SQ) constellations, and develop a quadrantbased harmonic mean analysis to evaluate the non-feedback and iterative-feedback asymptotic performance of the proposed constellations. In addition, we conceive a performance-analysis tool, referred to as multi-stream-based extrinsic information transfer (MS-EXIT) algorithm, for predicting the decoding thresholds of all individual coded-bit streams in the proposed SC P-LDPC-coded HM-BICM-ID systems. Simulation results not only agree well with the theoretical analyses, but also indicate that the proposed SC P-LDPC-coded HM-BICM-ID systems are remarkably superior to the state-of-the-art counterparts. Thereby, the proposed SC P-LDPCcoded HM-BICM-ID systems are competent to provide diverse quality-of-service (QoS) for future wireless applications, such as 6G-enabled Internet of Things (IoT).

Bit-Interleaved Coded Energy-Based Modulation With Iterative Decoding

“…In such cases, the efficient soft decoding is feasible by recursive processing over the Tanner graph of the code. As the main objective of this paper is to investigate turbo processing of information when EB modulator and non-coherent demodulator are employed, the comparative study of BICEM-ID under different encoding/decoding techniques, also incorporating non-coherent EBM into state-of-the-art schemes such as protograph LDPC BICM and spatially-coupled LDPC BICM [46]- [48], are interesting topic beyond the scope of this paper.…”

6G-Enabled Internet of Things: Vision, Techniques, and Open Issues

“…Yang et al [64] examined spatially coupled protograph systems. First, an information-theoretic approach was developed that can be used to assess the performance limitations of various layers in systems.…”

From 5G to 6G Technology: Meets Energy, Internet-of-Things and Machine Learning: A Survey

“…Three papers [177][178][179] proposed a low-cost sensor array design technique based on irregular subarrays, which divides the practical application challenge into two subproblems based on scene scale. To address these issues, other articles [180] offer practical recommendations such as deep Q-learning and federated learning-based transceivers, blockchainbased secure business models, homomorphic encryption, and distributed-ledger-based authentication systems.…”