Troll Systems Corporation SLLBTX646501 用户手册

23

 for the system modulation bit-rates

The coding rate setting determines how much forward error correction is used to reduce the video data 
loss while in use on moving vehicles, particularly aircraft. If the coding rate is set to 1/2,then half of the 
available data rate is being used for error correction and the remaining available data for video. 

NOTE: a code rate of 1/2 consumes most of the bandwidth for error correction, but also provides the 
highest degree of protection against video interference.

The guard interval provides resistance to multipath and co-channel interference. Longer guard intervals 
are used in areas where high levels of multipath are found such as dense metro areas. A guard interval of 
1/4 is the longest while, conversely, a guard interval 1/32 is the shortest

1/2

13.063

14.515

15.369

15.834

2/3

17.418

19.353

20.491

21.112

64-QAM

3/4

19.595

21.772

23.053

23.751

5/6

21.772

24.191

25.614

26.390

7/8

22.861

25.401

26.895

27.710

1/2

4.976

5.529

5.855

6.032

2/3

6.635

7.373

7.806

8.043

QPSK

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

1/2

9.953

11.059

11.709

12.064

2/3

13.271

14.745

15.612

16.086

16-QAM

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

1/2

14.929

16.588

17.564

18.096

2/3

19.906

22.118

19.516

24.128

64-QAM

3/4

22.394

24.882

26.346

27.144

5/6

24.882

27.647

29.273

30.160

7/8

26.126

29.029

30.737

31.668