tailieunhanh - Analytical analysis of implementation issues and its practical applicability in DVB-NGH single frequency networks

The role of the television has huge impact on the 21st century and basically the televisions either make use of SFN single frequency networks (SFN) or multi frequency networks (MFN) and both these networks are ideal for meeting the practical requirements either in local and global services. Another important drawback in these two networks are these two networks consumes huge amount of spectrum. The single frequency networks (SFN) main approach is it radiates the same amount of signal both in terms of time and frequency and Without violating the SFN principle, local services meant to address sub-regions of an SFN must therefore be transmitted throughout the whole network, causing inefficient distribution of local services. A novel approach has been proposed in this paper where high equipped next generation mobile broadcasting standard digital video broadcasting—next generation handheld for providing global and local contents in SFN topologies: hierarchical modulation (H-LSI) and orthogonal local services insertion (O-LSI) techniques. HLSI uses hierarchical modulation to transmit local services on top of the global services in areas close to the transmitters, by transmitting the local services in the low priority stream and the global services in the high priority stream. | Analytical analysis of implementation issues and its practical applicability in DVB-NGH single frequency networks