Analizing Of Key Technologies In DVB-H Data Link Layer

DVB-H based on DVB-T is a transmission standard, which is set down to provide multimedia services for handheld terminals by terrestrial digital broadcasting network. A full DVB-H system is a combination of elements of the physical and link layers, as well as service information. DVB-H makes use of the following technological elements for the link layer:(1)time-slicing technology in order to reduce the average power consumption of the handheld terminal and enable smooth and seamless service handover.(2)forward error correction for multiprotocol encapsulated data (MPE-FEC) technology for an improvement in C/N and Doppler performance in mobile channels, and also to improve the tolerance to impulse interference.This paper mainly studies MPE-FEC and the Time slicing technologies in DVB-H data link layer. An efficient decoding method which uses 2 bit erasure information is compared to the recommended method in the standard, which uses CRC32 to obtain erasure information. Computer simulation is accomplished to verify the new method can improve that the utilization of receivable data.Time slicing technology for soft handover algorithm is also analized.Five key problems needed to design soft handover algorithm in DVB-H network are proposed. Grounded upon post-processing of values based handover algorithm, variable post-processing of SNR fading rate based handover algorithm is put forward. In theory, Ping Pong effect,"fake signals", and power consumption are better solved in order to achieve seamless handover.