Another way to look at this :
DVB-T modulator maximum play rate depends on code rate, constellation, guard interval, bandwidth.
The maximum bit rate can be calculated as below.
The maximum bit rate can be calculated as below.
Tbandwidth = {6,000,000, 7,000,000, 8,000,000} in Hz for 6MHz, 7MHz, 8MHz
Tcode_rate = {1/2, 2/3, 3/4, 5/6, 7/8}
TConstellation = {2, 4, 6} <- QPSK = 2, 16QAM=4, 64QAM = 6
TGuardInterval = {4/5, 8/9, 16/17, 32/33}, 1/4 = 4/5, 1/8 = 8/9, 1/16 => 16/17, 1/32 => 32/33}
2K/8K mode does not matter
Tcode_rate = {1/2, 2/3, 3/4, 5/6, 7/8}
TConstellation = {2, 4, 6} <- QPSK = 2, 16QAM=4, 64QAM = 6
TGuardInterval = {4/5, 8/9, 16/17, 32/33}, 1/4 = 4/5, 1/8 = 8/9, 1/16 => 16/17, 1/32 => 32/33}
2K/8K mode does not matter
Maximum bit rate = 1512 / 2048 * 188 / 204 * 64 / 56 * TBandwidth * Tcode_rate * TConstellation * TGuardInterval (bps)
= 423 / 544 * TBandwidth * Tcode_rate * TConstellation * TGuardInterval (bps)
B (DVB-T) = 6.75 * 188*6*7/8*32/33*204 = 31.668
Bit Rate Calculation for DVB-T
8 MHz DVB-T COFDM Payload Data Rate
| ||||||
Useable Symbol Rate
|
6.75000
| Msym/s | ||||
OFDM Bandwidth
|
7.61161
| MHz | ||||
Modulation
Type
|
Code
Rate
|
Guard Interval
| ||||
1/4
|
1/8
|
1/16
|
1/32
| |||
QPSK
2
Bits/sym
|
1/2
|
4.976
|
5.529
|
5.855
|
6.032
| |
2/3
|
6.635
|
7.373
|
7.806
|
8.043
| ||
3/4
|
7.465
|
8.294
|
8.782
|
9.048
| ||
5/6
|
8.294
|
9.216
|
9.758
|
10.053
| ||
7/8
|
8.709
|
9.676
|
10.246
|
10.556
| ||
16-QAM
4
Bits/sym
|
1/2
|
9.953
|
11.059
|
11.709
|
12.064
| |
2/3
|
13.271
|
14.745
|
15.612
|
16.086
| ||
3/4
|
14.929
|
16.588
|
17.564
|
18.096
| ||
5/6
|
16.588
|
18.431
|
19.516
|
20.107
| ||
7/8
|
17.418
|
19.353
|
20.491
|
21.112
| ||
64-QAM
6
Bits/sym
|
1/2
|
14.929
|
16.588
|
17.564
|
18.096
| |
2/3
|
19.906
|
22.118
|
23.419
|
24.128
| ||
3/4
|
22.394
|
24.882
|
26.346
|
27.144
| ||
5/6
|
24.882
|
27.647
|
29.273
|
30.16
| ||
7/8
|
26.126
|
29.029
|
30.737
|
31.668
| ||
Payload Data Rates Mbit/s
| ||||||
Sys
Mode
|
Symbol
Time (us)
|
Guard Interval Length (us)
| ||||
1/4
|
1/8
|
1/16
|
1/32
| |||
2K
|
224
|
56
|
28
|
14
|
7
| |
8K
|
896
|
224
|
112
|
56
|
28
| |
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