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Computer generated holograms represent a novel digital media that with adequate processing tools and the advance of holographic display technologies will foster the development of true immersive video technologies applications. A digital hologram typically conveys a considerable amount of data making compression and image quality evaluation tools necessary for the development of practical applications. This paper proposes an objective evaluation of the performances of state-of-the-art compression techniques applied to digital holographic data. The experimental analysis takes into account several holographic images reconstructing the holograms from different perspectives and distances. The results of the exploratory study are reported, discussed and complemented with a statistical analysis of the hologram data under test, providing insights for computer-generated holography compression techniques design. [ABSTRACT FROM AUTHOR]

The impact of channel estimation errors is investigated in two-way relay networks (TWRNs) with two different channel state information (CSI) estimation schemes, namely separate and cascaded. In the former scheme, the relay node is chosen in accordance with the CSI of the individual channels between the source nodes and the relay node. By contrast, in the latter scheme, relay node selection is performed in accordance with the CSI of the cascaded channel between the two source nodes. For both estimation schemes, the effect of the CSI estimation error on the outage probability is examined by means of the Cramér–Rao lower bound. Moreover, in contrast to previous studies, the source nodes in the TWRN are assumed to have different estimation errors. The numerical results confirm the validity of the derived expressions and show that the presence of different estimation errors at the two source nodes has a significant effect on the performance of the TWRN. [ABSTRACT FROM PUBLISHER]

Two of the main drawbacks of the current broadcasting services are, on the one hand, the lack of flexibility to adapt to the new generation systems requirements, and on the other hand, the incapability of taking a piece of the current mobile services market. In this paper, layered division multiplexing (LDM), which grew out of the concept of Cloud Txn, is presented as a very promising technique for answering those challenges and enhancing the capacity of broadcasting systems. The major contribution of this paper is to present the first comprehensive study of the LDM performance behavior. In particular, in this paper, the theoretical considerations of the LDM implementation are completed with the first computer based simulations and laboratory tests, covering a wide range of stationary channels and the mobile TU-6 channel. The results will support LDM as a strong candidate for multiplexing different services in the next generation broadcasting systems, increasing both flexibility and performance. [ABSTRACT FROM PUBLISHER]