On the Efficiency of Layered Division Multiplexing for DVBS2X Satellite Communications Layered Division Multiplexing (LDM) is an effective approach for increase of data rates available for different services in wireless channels. LDM is included in ATSC 3.0 digital terrestrial TV system based on orthogonal frequency division multiplexing (OFDM) modulation. At the same time, satellite DVBS2 and DVBS2X systems that are currently used for DirectToHome (DTH) broadcasting include Variable Coding and Modulation (VCM) mode, which actually provides the opportunity to deliver different services to the consumers with Time Division Multiplexing (TDM). From this point of view, the investigation of LDM for satellite broadcast and communication systems and its comparison with VCM (TDM) approach becomes relevant. In this paper, several use cases were considered providing the delivery of High Definition (HD) and Ultra High Definition (UHD) TV services to customers as well as additional communication services. Analysis shows that LDM provides considerable gain in comparison with VCM for each use case.

Analysis of Channel Capacity for Threelayer Signals in Layered Division Multiplexing System A layered division multiplexing (LDM) system provides two or more services over one RF (radio frequency) channel. The LDM system draws much attention as a next generation broadcast communication system because it can provide 3 to 6 dB higher system gain than a time division multiplexing (TDM) or a frequency division multiplexing (FDM) systems. Many studies have been conducted to improve the transmission capacity and the performance of the twolayer LDM system. In order to achieve the additional transmission capacity, however, it is necessary to study terrestrial broadcasting system adopting LDM system with more than two layers. In this paper, we present the feasibility of a threelayer LDM system by analyzing its spectrum efficiency according to signaltonoise ratios (SNRs) and comparing it with those of TDM  FDM systems.