PowerPoint Presentation

1Technical Solutions For Local Service Insertion In DVB-NGH Single Frequency Networks

Under guidance of Mrs. S.Aruna KumariBy T. Jyothi Prakash 13N36D93122For broadcasting purpose we use the these frequency networks:Single frequency networksMulti frequency networksSingle frequency networks is a frequency network where the several transmitters transmits the same signal over the same frequency channel.Multi frequency networks is a frequency network where each transmitter transmits a signal with different frequencies.We use the SFN for Global Services and MFN for Local Services.Global Services is used for the services of users for the whole network.Local Services is used for the services of users as a sub regions in the Global Services.3Besides the optimal frequency reuse, it is usually expected that the more homogeneous distribution of received signal strength reception in an SFN will improve the quality of service.Nevertheless, it should be noted that not all the locations within the service area will benefit from the SFN configuration. Some areas will show a degraded quality caused by the SFN echoes.The SFN gain is defined as a parameter describing potential gain or interference. An unambiguous methodology to obtain the actual SFN gain is presented and the variation of the gain is investigated for a DVB-H network as a function of the signal strength difference received from different transmitters. 4In the existing method we find few problems like delay, loss of packets/data, echoes etc. when the number of users were increasedTwo main issues occur in this network are as followsOverlappingOverloadingThus we introduce two techniques to resolve this problem. They are:Hierarchical Modulation technique(H-LSI)Orthogonal Local Service Insertion technique(O-LSI)5Here in this project we implement the following techniques and network topologies for local service areas(LSAs) are:Hierarchical modulationOrthogonal local service insertion technique.

Hierarchical Modulation for local service insertion in DVB-NGH SFNs6H-LSI 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.

Structure of DVB-NGH LF with different types of PLPsType 1 and Type 2 are to comprise each transmission frame. Type 3 and Type 4 are used for H-LSI and O-LSI respectively.CTF( Channel Transfer Function)7

H-LSI transmitter Block Diagram8

Concept Of O-LSI technique9Coverage Performance results:H-LSI Coverage Performance:

10O-LSI Coverage Performance:

11In addition to the description of both H-LSI and O-LSI schemes, the applicability of these approaches in terms of network topologies, implementation issues, and performance evaluation are analysed.In extending this project SFN networks provide augmented spectrum efficiency as well as a quality of service improvement due to a more homogeneous distribution of the received signal strength over the coverage area. Nevertheless, some areas will also show degradation in practice.In order to improve the performance of the SFN operation, DVB-NGH standard incorporates multiple input single output (MISO) antenna diversity mechanisms.12THANK YOU