DVB-H is the transmission standard established by DVB to provide multimedia services to portable/handheld terminals through terrestrial digital broadcast networks. Dvbh is based on DVB-T standards, but compared with the DVB-T, The DVB-H is mainly to expand the DVB-T, so that it adapts to the requirements of handheld equipment, and the basic requirements of handheld equipment is:
- Mobile reception-this is nonsense
- Anti-interference-DVB is a one-way Broadcast System and cannot have a re-transmission mechanism
- Low Power Consumption-mobile devices have only one battery and no one wants to watch TV for a few minutes.
The physical layer of the DVB-T and the DVB-H is almost the same, the difference between the link and the above layers of the resolution. Below is the system diagram of the DVB-T transmitter in ETSI en 300 744, And the DVB-H is the same. The system input is 13818 ts, and the output is the RF signal. As for the energy dispersion, internal and external code, and internal and external interweaving, it is not very clear yet. After all, it is handled using others' IP cores and APIs, and there is no need to know too much, wait for time to study. For the 13818 TS Stream carried by both. DVB-T ts package data mainly PES, and 13818 system almost, according to his standard to solve OK, implementation is very simple. DVB-H ts is mainly two types: psi/Si and MPE-FEC, MPE-FEC encapsulation of the IP package, which is the essence of DVB-H. In general, DVB-H has added new technical modules in DVB-T mainly including:
- Time slice: Based on the time-division multiplexing technology, used to save the power consumption of the Receiving Terminal. Theoretically, the power consumption can be reduced to 1/10, And the MAC (Media Access Control) part of time slice information in the MPE-FEC section is defined;
- MPE-FEC: Based on RS error correction coding technology, additional forward error correction coding is added for MPE, which is used to improve the system's ability to move and resist impulse interference;
- 4 K mode: 4 K mode is added based on the 2 K and 8 K transmission modes of the DVB-T, which is used to improve the flexibility of network design;
- DVB-H TPS: specially designed transport parameter signaling for DVB-H to improve system synchronization and business access speed.
