In this paper, we evaluate a multilevel coding (MLC) scheme with multistage decoding (MSD) designed for satellite broadcasting communications. The impact of three different satellite system impairments on the decoding performance is analyzed. First, the influence of errors introduced by the channel estimation is discussed, assuming a typical data-aided (DA) channel estimator with different pilot lengths. Second, the impact of the residual phase noise present after the phase recovery is investigated using a model based on a normal distribution. Finally, the degradation introduced by the non-linearities of the satellite power amplifiers is also analyzed. The impact of these effects is investigated via the mutual information. Besides, bit error rate (BER) simulations are performed for each impairment effect. The considered MLC scheme is compared to a classical bit-interleaved coded modulation (BICM) scheme, showing that the MLC scheme provides different grades of robustness for each level.

In order to reduce the computational complexity of maximum-likelihood symbol estimation (MLSE) demapping of multilevel codes which is based on block partitioning and which produces soft input for a multistage decoding (MSD) process, three different demapping algorithms are proposed. It is theoretically proven that the proposed algorithms can reduce exponentially increasing computational complexity of the MLSE demapping algorithm to a constant complexity (neglecting comparisons). It is shown by extensive simulations for AWGN and Rayleigh fading channels that the proposed low complexity demapping algorithms can achieve near MLSE performance.

We introduce the use of multidimensional (MD) constellations in a multilevel coding (MLC) scheme with multi-stage decoding (MSD) designed for broadcasting communications, where services with different quality of service (QoS) are desirable. We show that the number of different protection levels increases when using MD constellations. Besides, the appropriate block labeling (BL) partitioning for an MD constellation is found by applying the binary switching algorithm (BSA) as an efficient search algorithm. Two cost functions for the BSA are proposed based on the BL criterion. Some methods to construct an appropriate MD constellation are presented, including the use of uniform and non-uniform component constellations. The viability of the proposed MD constellations approach for broadcasting with different protection levels is evaluated analyzing the mutual information (MI) of each level. Finally, we present a comparison between a unidimensional and a multidimensional scheme which again demonstrates the benefits of the proposed scheme.

In this paper, we evaluate a multilevel coding (MLC) scheme with multi-stage decoding (MSD) designed for satellite broadcasting communications, where services with different quality of service (QoS) are desirable. A simple Land-Mobile-Satellite (LMS) channel model is presented, based on channel states and their transitions. The instantaneous channel capacity for suburban and forest scenarios is calculated using the mutual information concept. An established transmission scheme for satellite broadcasting, which uses bit-interleaved coded modulation (BICM) with Gray mapping, is compared with the MLC scheme in terms of channel capacity and outage probability. The effect of removing a long channel interleaver in the physical layer is analyzed, showing that the MLC scheme is a good alternative to BICM for satellite broadcasting.

In this paper, we propose a multilevel coding (MLC) scheme suitable for satellite communications, where different QoS levels are required. We introduce a novel characterization of schemes based on mutual information, called multi-stage decoder (MSD) charts, to aid in the design and evaluation of multilevel coding systems. This characterization method finds the optimal set of code rates for the MLC scheme for a set of required SNR operation points. On the other hand, fixing the code rates to find out the operation points of SNR is also possible. Performance of common mapping strategies used in MLC schemes, as block labeling and Ungerbock labeling, are evaluated using MSD charts. An established transmission scheme for satellite broadcasting, European Satellite Digital Radio (ESDR) standard, is compared with the proposed MLC scheme, showing that the MLC scheme is able to work in lower SNR regions and provides more flexibility in designing the levels.