In previous studies, a very sparse low-density parity-check (LDPC) code was designed for triple-level cell (TLC) NAND flash using non-Gray mapping, which is able to achieve comparable error-rate performance to the conventional Gray mapping-based scheme. Although a sparse LDPC code can be of benefit to hardware implementations of an iterative demodulation and decoding (IDD) scheme, difficulties emerge, such as latency issue between the decoder and demodulator, when compared to non-IDD schemes. In this paper, a hardware-friendly structure interleaver is used such that a shuffle-based IDD scheme can be realized efficiently. Compared to the conventional Gray-based non-IDD scheme and layered-based IDD scheme, the proposed shuffled-based IDD scheme can provide a better hardware efficiency and better error-rate performance.

In this paper, we investigate a Raptor-coded distributed noncoherent scheme based on a non-orthogonal spacetime modulation (NOSTM) signal and a dynamic decode-and-forward (DF) relaying scenario. The distributed NOSTM signal is firstly proposed based on unitary space-time modulation (USTM) and spatial multiplexing (SM). The dynamic DF relaying protocol is investigated to process the non-orthogonal feature of the NOSTM signal. A Raptor-coded distributed scheme is then constructed for the relay network, and the corresponding transmission and reception procedures are also investigated. It is shown that the throughput performance can be effectively improved, especially for cases when the location of the chosen relay nodes is distant from the source node.

In this paper, we investigate Raptor-coded distributed unitary space-time modulation (USTM) schemes, where both the amplify-and-forward (AF) and decode-and-forward (DF) relaying scenarios are considered, under a wireless relay network with arbitrary path gains for the channel fading coefficients. First, the AF and DF relaying procedures are investigated based on the use of an inner USTM signal and an outer Raptor code, and the related noncoherent detectors are also derived. The constellation search for the USTM signal, as well as the optimization for the Raptor code, is then investigated in order to enhance the system performance. It is shown that the designed systems effectively approach the predicted limit in throughput performances and outperform the noncoherent distributed MIMO scheme reported in the previous literature.