DVB-T2
Digital Video Broadcasting — Second Generation Terrestrial (DVB-T2) is an extension of DVB-T which allows for significantly higher data rates. The following settings are available if you select DVB-T2.
Setting | Description |
---|---|
Bandwidth | Specifies the bandwidth of operation. DVB-T2 provides additional bandwidths compared to DVB-T. |
Carriers |
Choose the mode of operation, 1K, 2K, 4K or 8K mode. Use 2K mode for single transmitter operation and for small single frequency networks with limited transmitter distances. Use 8K mode both for single transmitter operation and for small and large single frequency networks. |
Constellation |
DVB-T2 offers different modulation schemes: QPSK, 16QAM, 64QAM, Rotated QPSK, Rotated 16QAM and Rotated 64QAM. Lower order modulation formats like QPSK do not transmit data as fast as the higher modulation formats such as 64QAM, but they can be received when signal strengths are lower. Note that as the QAM order increases, there is a higher possibility of introducing data errors since these schemes are less resilient to noise and interference. Choose rotated modulation to lower the dynamical range of fluctuations in the signal and to improve the data rate. |
Code Rate |
Match the code rate to the requirements of the broadcast network. The higher the level of error correction that is applied, the greater the level of supporting error correction data that needs to be transmitted, which reduces the data rate of the transmission. For example, if you select 2/3, for every 2 bits of data, you are sending out 3 bits, one of which is for error correction. |
Guard Interval |
Choose the appropriate guard interval so that distinct transmissions do not interfere with each other. In DVB-T2, four guard intervals are available: 1/32 provides the lowest protection and the highest data rate, 1/4 results in the best protection but the lowest data rate. |
Pilot Pattern |
Pilots are needed to adapt transmissions to current channel conditions. DVB-T2 has eight different patterns. Choose the appropriate pattern depending on network type and reception conditions or select ‘Auto’. If you choose a specific pattern, you can also set the frame duration and forward error correction (FEC) block size. |
Frame duration | Frame duration ranges between 10 and 43ms and allows you to trade modulation delay, bit rate efficiency and interleaving performance. |
FEC Block Size |
This is a trade-off parameter, with shorter FEC blocks giving finer control over achievable bit rate but requiring more overhead and thus not as efficient as long frames. Choose between short FEC frame (16,200 bits) and long FEC frame (64,800 bits). |