System Differences With DVB-T
The following table reports a comparison of available modes in DVB-T and DVB-T2.
| DVB-T | DVB-T2 | |
|---|---|---|
| Input Interface | Single Transport Stream (TS) | Multiple Transport Stream and Generic Stream Encapsulation (GSE) |
| Modes | Constant Coding & Modulation | Variable Coding & Modulation |
| Forward Error Correction (FEC) | Convolutional Coding + Reed Solomon 1/2, 2/3, 3/4, 5/6, 7/8 | LDPC + BCH 1/2, 3/5, 2/3, 3/4, 4/5, 5/6 |
| Modulation | OFDM | OFDM |
| Modulation Schemes | QPSK, 16QAM, 64QAM | QPSK, 16QAM, 64QAM, 256QAM |
| Guard Interval | 1/4, 1/8, 1/16, 1/32 | 1/4, 19/256, 1/8, 19/128, 1/16, 1/32, 1/128 |
| Discrete Fourier transform (DFT) size | 2k, 8k | 1k, 2k, 4k, 8k, 16k, 32k |
| Scattered Pilots | 8% of total | 1%, 2%, 4%, 8% of total |
| Continual Pilots | 2.6% of total | 0.35% of total |
For instance, a UK MFN DVB-T profile (64-QAM, 2k mode, coding rate 2/3, guard interval 1/32) and a DVB-T2 equivalent (256-QAM, 32k, coding rate 3/5, guard interval 1/128) allows for an increase in bit rate from 24.13 Mbit/s to 35.4 Mbit/s (+46.5%). Another example, for an Italian SFN DVB-T profile (64-QAM, 8k, coding rate 2/3, guard interval 1/4) and a DVB-T2 equivalent (256-QAM, 32k, coding rate 3/5, guard interval 1/16), achieves an increase in bit rate from 19.91 Mbit/s to 33.3 Mbit/s (+67%).
Recommended maximum bit-rate configurations for 8 MHz bandwidth, 32K FFT, guard interval 1/128, pilot pattern 7:
| Modulation | Code rate | Bitrate Mbit/s | Frame length LF | FEC blocks per frame |
|---|---|---|---|---|
| QPSK | 1/2 | 7.4442731 | 60 | 50 |
| 3/5 | 8.9457325 | |||
| 2/3 | 9.9541201 | |||
| 3/4 | 11.197922 | |||
| 4/5 | 11.948651 | |||
| 5/6 | 12.456553 | |||
| 16-QAM | 1/2 | 15.037432 | 60 | 101 |
| 3/5 | 18.07038 | |||
| 2/3 | 20.107323 | |||
| 3/4 | 22.619802 | |||
| 4/5 | 24.136276 | |||
| 5/6 | 25.162236 | |||
| 64-QAM | 1/2 | 22.481705 | 60 | 151 |
| 3/5 | 27.016112 | |||
| 2/3 | 30.061443 | |||
| 3/4 | 33.817724 | |||
| 4/5 | 36.084927 | |||
| 5/6 | 37.618789 | |||
| 256-QAM | 1/2 | 30.074863 | 60 | 202 |
| 3/5 | 36.140759 | |||
| 2/3 | 40.214645 | |||
| 3/4 | 45.239604 | |||
| 4/5 | 48.272552 | |||
| 5/6 | 50.324472 |
Read more about this topic: DVB-T2
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